TWI734601B - air conditioner - Google Patents

Abstract

Provided is an air conditioner that keeps the outdoor heat exchanger in a clean state. The air conditioner (100) is equipped with: a refrigerant circuit (Q) with a compressor (11), an indoor heat exchanger (16), an expansion valve (15), and an outdoor heat exchanger (12); and at least for the compressor (11) and the expansion valve (15) are used as a control unit, and the aforementioned control unit performs the first process of freezing or dew condensation on the lower part of the outdoor heat exchanger (12). With this, the outdoor heat exchanger (12) of the air conditioner (100) is in a clean state.

Description

air conditioner

The present invention relates to an air conditioner.

As a technique for cleaning the heat exchanger of an air conditioner, for example, Patent Document 1 describes "corresponding to the target evaporating temperature and the actual evaporating temperature of the heat exchanger to be cleaned to exchange heat The evaporation temperature of the heat exchanger is adjusted, and the heat exchanger to be cleaned is frosted.” [Prior Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2018/086176

[The problem to be solved by the invention]

However, in areas near the coast, the sea breeze is blowing, so the salt tends to adhere to the outdoor heat exchanger installed outdoors. If the outdoor heat exchanger is used for a long period of time in such a state where the salt is attached, the outdoor heat exchanger may be corroded due to the influence of the salt.

For example, when the outdoor heat exchanger is frosted based on the technique of Patent Document 1, the water produced by the dissolution of the frost drips through the fins of the outdoor heat exchanger, and the salt adheres to the fins. The ingredients will dissolve in the water. As a result, near the lower end of the outdoor heat exchanger, since high-concentration salt water flows down through the fins, there is a possibility that salt remains near the lower end of the outdoor heat exchanger. Regarding the technology of Patent Document 1, it is desired to make the outdoor heat exchanger in a cleaner state.

Therefore, the subject of the present invention is to provide an air conditioner that keeps the outdoor heat exchanger in a clean state. [Means to solve the problem]

In order to solve the aforementioned problems, the air conditioner of the present invention uses the control unit to perform the first process of making the outdoor heat exchanger function as an evaporator and freezing or condensing the lower part of the outdoor heat exchanger. In the aforementioned first process , At least a part of the lower part of the outdoor heat exchanger is frozen, and at least a part of the upper part of the outdoor heat exchanger is not frozen. In addition, other configurations are explained in the embodiment. [Effects of the invention]

According to the present invention, it is possible to provide an air conditioner that makes the outdoor heat exchanger in a clean state.

＜＜The first embodiment＞＞ 〈Constitution of air conditioner〉

Fig. 1 is a configuration diagram of an air conditioner 100 according to the first embodiment. In addition, the solid arrow in Fig. 1 represents the flow of refrigerant during the heating cycle. On the other hand, the dashed arrow in Fig. 1 represents the flow of refrigerant when the cold air is circulated. The air conditioner 100 is a device for air conditioning such as cooling operation or heating operation. As shown in FIG. 1, the air conditioner 100 includes a compressor 11, an outdoor heat exchanger 12, an outdoor heat exchanger temperature sensor 13, an outdoor fan 14, and an expansion valve 15. In addition, the air conditioner 100 also includes an indoor heat exchanger 16, an indoor fan 17, and a four-way valve 18 in addition to the aforementioned configuration.

The compressor 11 is a machine that compresses a low-temperature and low-pressure gas refrigerant and discharges it as a high-temperature and high-pressure gas refrigerant, and is equipped with a compressor motor 11a as a driving source. The outdoor heat exchanger 12 is a heat exchanger that exchanges heat between the refrigerant circulating in the heat transfer pipe g (refer to FIG. 2) and the outside air sent from the outdoor fan 14.

The outdoor heat exchanger temperature sensor 13 is a sensor that directly or indirectly detects the temperature of the outdoor heat exchanger 12. In the example of FIG. 1, when the refrigerant is circulated by the heating cycle (see the solid arrow in FIG. 1), it is located near the upstream end of the outdoor heat exchanger 12 (near the lower end in the vertical direction, refer to FIG. 3) ) Is provided with an outdoor heat exchanger temperature sensor 13 at the piping k1.

The outdoor fan 14 is a fan that sends outside air to the outdoor heat exchanger 12. The outdoor fan 14 is provided with an outdoor fan motor 14a as a driving source, and is installed in the vicinity of the outdoor heat exchanger 12. As such an outdoor fan 14, for example, a propeller fan can be used, but the system is not limited to this. The expansion valve 15 is a valve that decompresses the refrigerant condensed by the "condenser" (one of the outdoor heat exchanger 12 and the indoor heat exchanger 16). In addition, the refrigerant decompressed at the expansion valve 15 is guided to the "evaporator" (the other of the outdoor heat exchanger 12 and the indoor heat exchanger 16).

The indoor heat exchanger 16 is a heat exchange for heat exchange between the refrigerant circulating in the heat pipe (not shown) and the indoor air (air in the air-conditioned space) sent from the indoor fan 17 Device. The indoor fan 17 is a fan that sends indoor air to the indoor heat exchanger 16. The indoor fan 17 is provided with an indoor fan motor 17a (refer to FIG. 4) as a driving source, and is installed in the vicinity of the indoor heat exchanger 16.

In addition, the upper and lower wind direction plate r is installed at the indoor unit Ui to adjust the wind direction of the air blown from the indoor unit Ui in the upper and lower direction. In addition, although illustration is omitted in FIG. 1, a left and right wind direction plate for adjusting the wind direction of the air blown from the indoor unit Ui in the left and right direction is also provided.

The four-way valve 18 is a valve that switches the flow path of the refrigerant in accordance with the operation mode of the air conditioner 100. For example, during cooling operation (refer to the dashed arrow in FIG. 1), in the refrigerant circuit Q, the refrigerant sequentially passes through the compressor 11, the outdoor heat exchanger 12 (condenser), the expansion valve 15 and the indoor heat exchanger 16 ( Evaporator) for circulation.

On the other hand, during heating operation (refer to the solid arrow in FIG. 1), in the refrigerant circuit Q, the refrigerant sequentially passes through the compressor 11, the indoor heat exchanger 16 (condenser), the expansion valve 15 and the outdoor heat exchange The device 12 (evaporator) is circulated.

That is, in the refrigerant circuit Q that circulates the refrigerant through the compressor 11, the "condenser", the expansion valve 15 and the "evaporator" in this order, one of the aforementioned "condenser" and "evaporator", The system is the outdoor heat exchanger 12, and the other is the indoor heat exchanger 16.

In addition, in the example of FIG. 1, the compressor 11, the outdoor heat exchanger 12, the outdoor heat exchanger temperature sensor 13, the outdoor fan 14, the expansion valve 15, and the four-way valve 18 are installed at the outdoor unit Uo. . On the other hand, the indoor heat exchanger 16 and the indoor fan 17, as well as the upper and lower wind direction plates r, are installed in the indoor unit Ui.

Figure 2 is a perspective view of the state where the side plate and top plate of the frame of the outdoor unit Uo have been removed. In addition, in FIG. 2, the illustration of the expansion valve 15 (refer to FIG. 1) and the four-way valve 18 (refer to FIG. 1) is omitted. In the example of FIG. 2, the outdoor heat exchanger 12 which is L-shaped when viewed in plan is installed at the bottom plate d of the frame of the outdoor unit Uo. The outdoor heat exchanger 12 is provided with a plurality of fins f arranged at specific intervals, and a plurality of heat pipes g penetrating the fins f. However, through the aforementioned heat pipe g, the refrigerant circulates while performing a specific meandering.

The accumulator 19 (not shown in FIG. 1) is a shell-shaped member for separating the refrigerant toward the compressor 11 from gas and liquid, and is connected to the suction side of the compressor 11. In the example of FIG. 2, the space in which the compressor 11 and the accumulator 19 are installed, and the space in which the outdoor fan 14 is installed are partitioned by a partition wall e. The circuit component box h shown in FIG. 2 is a box for storing the substrate (not shown) on which the outdoor control circuit 32 (refer to FIG. 4) described later is installed.

As mentioned above, when the outdoor unit Uo is installed near the coast or the like, there are often cases in which air containing salt is introduced into the outdoor unit Uo. In this way, due to the natural wind or the driving of the outdoor fan 14, the salt will adhere to the outdoor heat exchanger 12.

Therefore, in the first embodiment, the control unit 30 (refer to FIG. 4) described later is configured to freeze the lower part of the outdoor heat exchanger 12. This control is called "freezing cleaning" (registered trademark) of the outdoor heat exchanger 12. By this, the lower part of the outdoor heat exchanger 12 is frozen in a short time, and the salt or dust adhering to the lower part of the outdoor heat exchanger 12 can be washed away. Hereinafter, the salt or dust is referred to as "salt, etc.".

Fig. 3 is an explanatory diagram showing the pass of the outdoor heat exchanger 12 of the air conditioner. In addition, in FIG. 3, the direction of the flow of the refrigerant in the freezing washing of the outdoor heat exchanger 12 (heating cycle) is shown as an arrow. In the example of FIG. 3, as the fin f of the outdoor heat exchanger 12, rectangular fins fa and fb elongated in the vertical direction are arranged side by side in the left-right direction. One of the fins fa is in front of the paper-the deep prescription is arranged in multiples at specific intervals, and the heat pipe g penetrates these fins fa. In addition, the same applies to the other fin fb. On the other hand, via the heat transfer pipe g, the refrigerant system specifically circulates in the upper part P1 and the lower part P2 of the outdoor heat exchanger 12.

Here, the upper part P1 of the outdoor heat exchanger 12 is, for example, a part higher than the middle position R of the height of the outdoor heat exchanger 12 in the up-down direction. On the other hand, the lower part P2 of the outdoor heat exchanger 12 is, for example, a part lower than the middle position R of the height of the outdoor heat exchanger 12 in the vertical direction.

In the example of FIG. 3, the refrigerant decompressed by the expansion valve 15 (refer to FIG. 1) circulates in the pipe k1, and is further divided into the pipes ka and kb at the distributor w1. The refrigerant flowing in these pipes ka and kb is guided to the heat transfer pipe g of the lower part P2 of the outdoor heat exchanger 12. In other words, in the process of freezing and washing the outdoor heat exchanger 12 (the first process), the refrigerant decompressed by the expansion valve 15 (see FIG. 1) is guided to the outdoor heat exchanger 12 The downstream ends v of the pipes ka and kb are connected to the lower part P2 of the outdoor heat exchanger 12.

With this, for example, in the freezing and washing of the outdoor heat exchanger 12, since the low-temperature and low-pressure refrigerant flows to the heat transfer pipe g of the lower part P2 of the outdoor heat exchanger 12, the lower part P2 of the outdoor heat exchanger 12 is It becomes easy to freeze. Therefore, afterwards, by melting the frost or ice in the lower part P2 of the outdoor heat exchanger 12, the salt in the lower part P2 is washed away.

In the example of FIG. 3, the refrigerant that circulates in the heat transfer pipe g and the pipe kh in the lower part P2 of the outdoor heat exchanger 12 through the pipe kb is distributed to the pipes ki and kj at the distributor w2. middle. The refrigerant flowing in one of the pipes ki is guided to the pipe km through the heat transfer pipe g on the upper part P1 of the outdoor heat exchanger 12. The refrigerant flowing in the other pipe kj is guided to the pipe kn via the heat transfer pipe g on the upper part P1 of the outdoor heat exchanger 12.

In the example of FIG. 3, the refrigerant flowing through the heat transfer pipe g and the pipe kc of the lower part P2 of the outdoor heat exchanger 12 through the pipe ka is diverted to the pipes kd and ke at the distributor w3. middle. The refrigerant flowing in one of the pipes kd is guided to the pipe kf via the heat transfer pipe g of the upper portion P1 of the outdoor heat exchanger 12. The refrigerant flowing in the pipe ke on the other side is guided to the pipe kg via the heat transfer pipe g on the upper part P2 of the outdoor heat exchanger 12. Although not shown, the refrigerant circulating in the aforementioned pipes kf, kg, km, and kn is specifically merged and guided to the suction side of the compressor 11 (refer to FIG. 1).

Fig. 4 is a functional block diagram of the air conditioner 100. The indoor unit Ui shown in FIG. 4, in addition to the aforementioned indoor fan motor 17a, also has a remote control transmitter and receiver 21, an indoor temperature sensor 22, a left and right wind direction board motor 23, and an up and down wind direction board. The motor 24, the indicator light 25, and the indoor control circuit 31 are used.

The remote control transmitting and receiving unit 21 exchanges specific information between itself and the remote control 40 through infrared communication or the like. The indoor temperature sensor 22 is a sensor that detects the indoor temperature (temperature of the air-conditioned space), and is installed in a specific place of the indoor unit Ui. The signal received from the remote controller 40 via the remote controller sending and receiving unit 21 and the detection value of the room temperature sensor 22 are output to the room control circuit 31 described later.

The indoor fan motor 17a is the driving source of the indoor fan 17 (refer to FIG. 1) as described above. The motor 23 for the left and right wind direction plates is a motor that adjusts the angle of the left and right wind direction plates (not shown) in the left and right directions. The motor 24 for the up and down wind direction board is a motor that adjusts the angle of the up and down direction of the up and down wind direction board r (refer to FIG. 1). The display lamp 25 is a lamp for performing a specific display, and is installed at a specific place of the indoor unit Ui. For example, in the process of freezing and washing the outdoor heat exchanger 12, the indicator lamp 25 is specifically lit (or turned off) by the control unit 30.

Although the indoor control circuit 31 is not shown in the figure, it is constituted by electronic circuits including CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), various interfaces, and the like. In addition, the program stored in the ROM is read out and expanded in the RAM, and the CPU executes various processes.

As shown in FIG. 4, the indoor control circuit 31 includes a memory unit 31a and an indoor control unit 31b. In the memory portion 31a, in addition to a specific program, the data received by the signal receiving portion 21 sent via the remote control and the detection values of each sensor are also stored. The indoor control unit 31b controls the indoor fan motor 17a, the left and right wind direction board motors 23, the up and down wind direction board motors 24, the indicator lights 25, etc., based on the data stored in the memory unit 31a.

The outdoor unit Uo is equipped with an outdoor temperature sensor 26 and an outdoor control circuit 32 in addition to the aforementioned configuration (refer to FIG. 1). The outdoor temperature sensor 26 is a sensor that detects the outdoor temperature and is installed at a specific place of the outdoor unit Uo. The outdoor heat exchanger temperature sensor 13 (also refer to FIG. 1) is a sensor that detects the temperature of the outdoor heat exchanger 12 as described above. The detection values of the outdoor temperature sensor 26 and the outdoor heat exchanger temperature sensor 13 are output to the outdoor control circuit 32.

Although not shown, the outdoor control circuit 32 is constituted by electronic circuits including CPU, ROM, RAM, various interfaces, etc., and is connected to the indoor control circuit 31 via a communication line. As shown in FIG. 4, the outdoor control circuit 32 includes a memory unit 32a and an outdoor control unit 32b.

In the memory portion 32a, in addition to the specific program and the data received from the indoor control circuit 31 via the communication line, the detection value of each sensor is also stored. The outdoor control unit 32b controls the compressor motor 11a, the outdoor fan motor 14a, the expansion valve 15, the four-way valve 18, etc., based on the data stored in the memory unit 32a. Hereinafter, the indoor control circuit 31 and the outdoor control circuit 32 are collectively referred to as the "control unit 30". Next, the processing of the control unit 30 related to the freezing and washing of the outdoor heat exchanger 12 will be described with reference to FIG. 5.

<Handling by the control department> Fig. 5 is a flowchart of the freezing and washing process related to the outdoor heat exchanger 12 (refer to Figs. 1 and 4 as appropriate). In addition, at the time of "START" in FIG. 5, it is assumed that the air conditioning operation of the air conditioner 100 is stopped. In step S101 in FIG. 5, the control unit 30 determines whether or not the start condition of the freezing washing of the outdoor heat exchanger 12 is satisfied. If a specific example is given, when a specific period has elapsed since the end of the previous freezing washing, the control unit 30 determines that the freezing washing start condition of the outdoor heat exchanger 12 has been changed. Satisfy (S101, Yes), and proceed to the processing of step S102. On the other hand, when the specific period has not elapsed since the end of the previous freezing washing, the control unit 30 determines that the freezing washing start condition of the outdoor heat exchanger 12 is not satisfied (S101 , No), and will be related to the end of the process of freezing and washing (END).

In step S102, the control unit 30 freezes the lower part P2 (refer to FIG. 3) of the outdoor heat exchanger 12 as a freeze cleaning of the outdoor heat exchanger 12 (that is, performs the "first process"). For a specific description, the control unit 30 circulates the refrigerant in the refrigerant circuit Q by circulating warm air, and makes the outdoor heat exchanger 12 function as an evaporator, and makes the lower part P2 of the outdoor heat exchanger 12 freeze.

In addition, the matter of "freezing the lower part P2 of the outdoor heat exchanger 12" includes the matter of freezing at least a part of the lower part P2 in addition to the aforementioned matter of freezing the entire lower part P2. In the freezing of the lower part P2 of the outdoor heat exchanger 12 (during the first process), the control unit 30 may also be configured to freeze at least a part of the lower part P2 of the outdoor heat exchanger 12 and to freeze the outdoor heat exchanger 12 At least a part of the upper part P1 of 12 is not frozen.

Also, during freezing (in the first process) of the lower part P2 of the outdoor heat exchanger 12 (refer to FIG. 3), the control unit 30, preferably, compares the opening degree of the expansion valve 15 with that during normal heating operation. Shrink even more. By this, the low pressure refrigerant whose saturation temperature (evaporation temperature) is lower than 0° C. flows into the lower part P2 of the outdoor heat exchanger 12. As a result, the moisture in the air forms frost and freezes at the lower part P2 of the outdoor heat exchanger 12. By this, if the frost or ice in the lower part P2 of the outdoor heat exchanger 12 melts, the salt and the like in the lower part P2 of the outdoor heat exchanger 12 are washed away by the water. Therefore, since the lower part P2 of the outdoor heat exchanger 12 where the salt is particularly likely to remain is cleaned, the corrosion of the lower part P2 can be suppressed.

Fig. 6 is a timing chart showing the states of the compressor 11, the four-way valve 18, the expansion valve 15, the outdoor fan 14, and the indoor fan 17 (refer to Figs. 1 and 4 as appropriate). In addition, the horizontal axis in FIG. 6 is time. In addition, the vertical axis in FIG. 6 shows the state of the compressor 11 and the four-way valve 18 and so on. In the example of FIG. 6, the air conditioner 100 is in a stopped state until time t1. After that, as shown in the state of the four-way valve 18, immediately before the aforementioned stop state, it is assumed that, for example, an operation with cooling air is performed. In addition, in FIG. 6, an example is shown in which "after freezing at the lower part P2 of the outdoor heat exchanger 12 (refer to FIG. 3), the control unit 30 sequentially performs thawing and drying of the outdoor heat exchanger 12". In addition, in the aforementioned flowchart of FIG. 5, the description of thawing and drying of the outdoor heat exchanger 12 is omitted.

When freezing the outdoor heat exchanger 12, the control unit 30 switches the four-way valve 18 to the heating cycle at time t1, and shrinks the expansion valve 15 to a specific opening degree u1 to drive the compressor 11. As mentioned above, the specific opening degree u1 is a smaller opening degree than during normal heating operation. As a result, at the lower part P2 of the outdoor heat exchanger 12, which is an evaporator, a low-temperature and low-pressure refrigerant circulates, and the lower part P2 is frozen. The control unit 30, for example, makes the detection value of the outdoor heat exchanger temperature sensor 13 (refer to FIG. 1 and FIG. 3) to be in a sub-freezing state for a specific time (time t1 to t2).

During the freezing of the outdoor heat exchanger 12 (time t1 to t2), the control unit 30 preferably drives the outdoor fan 14 and the indoor fan 17. By this, the heat exchange system between the outdoor heat exchanger 12 and the indoor heat exchanger 16 is promoted. In addition, in the process of freezing and washing the outdoor heat exchanger 12, the control unit 30 preferably rotates the outdoor fan 14 at a lower speed than during normal air-conditioning operation. As a result, even when the temperature of the outside atmosphere is relatively high, frost or ice can easily grow when the outdoor heat exchanger 12 freezes. That is, the outdoor heat exchanger 12 is made to function as an evaporator, and it is also possible to suppress a situation in which a large amount of high-temperature outside air is blown into the outdoor heat exchanger 12.

In addition, in the process of freezing and washing the outdoor heat exchanger 12, the control unit 30 preferably reduces the rotation speed of the outdoor fan 14 as the outdoor temperature becomes higher. With this, for example, in summer when the outdoor temperature is high, the air volume of the outdoor fan 14 is reduced, so the freezing of the outdoor heat exchanger 12 becomes easy to progress. In addition, the matter of "the higher the outdoor temperature is, the more the rotation speed of the outdoor fan 14 is reduced" also includes the matter of stopping the outdoor fan 14 when the outdoor temperature is higher.

Furthermore, in the freezing and washing process of the outdoor heat exchanger 12 (during the first process), the control unit 30, preferably, makes the indoor fan 17 rotate at the lowest rotation speed (lower than the rotation speed during normal air-conditioning operation). Limit) and rotate at a higher speed. By this, the freezing of the outdoor heat exchanger 12 can be further advanced. However, in order to reduce the air volume when warm air is blown from the indoor unit Ui, it is desirable to set the indoor fan 17 to a rotation speed lower than the central value of the rotation speed during normal air conditioning operation. The aforementioned "central value of rotation speed" refers to the median value between the minimum rotation speed and the maximum rotation speed during normal air-conditioning operation. In addition, although illustration is omitted in FIG. 6, in the process of freezing and washing the outdoor heat exchanger 12 (during the first process), the control unit 30, preferably, sets the upper and lower wind direction plates r (refer to FIG. 1) Set it to be more upward than the horizontal direction. That is, preferably, the control unit 30 adjusts the angle of the vertical wind direction plate r so that the direction of the warm wind blown from the indoor unit Ui becomes higher than the horizontal direction. By this, it is possible to prevent the warm wind from directly blowing on the user.

After freezing the lower part P2 of the outdoor heat exchanger 12 at times t1 to t2 in FIG. 6 (after the first processing), the control unit 30 defrosts the outdoor heat exchanger 12 at times t2 to t3. In the example of FIG. 6, the control unit 30 stops the compressor 11 and also stops the outdoor fan 14 and the indoor fan 17. In addition, the control unit 30 defrosts the outdoor heat exchanger 12 by setting the opening degree of the expansion valve 15 to be larger than when the outdoor heat exchanger 12 is frozen (at the time of the first process). In the example of FIG. 6, during the thawing of the outdoor heat exchanger 12, the expansion valve 15 is fully opened.

With this, the high-temperature refrigerant of the indoor heat exchanger 16 that functions as a condenser during the freezing of the outdoor heat exchanger 12 flows into the outdoor heat exchanger 12 on the low pressure side through the expansion valve 15. As a result, the frost or ice in the lower part P2 of the outdoor heat exchanger 12 is melted, and the outdoor heat exchanger 12 is washed. In addition, even if the opening degree of the expansion valve 15 is not increased during thawing, the frost or ice of the outdoor heat exchanger 12 will melt by heat exchange with the outside atmosphere, but the expansion The opening degree of the valve 15 is increased, and the thawing system of the outdoor heat exchanger 12 is promoted as described above.

After the outdoor heat exchanger 12 is defrosted at time t2 to t3 in FIG. 6, at time t3 to t4, the control unit 30 drives the outdoor fan 14 to dry the outdoor heat exchanger 12. For example, after the outdoor heat exchanger 12 is thawed, the control unit 30 drives the outdoor fan 14 at the first rotation speed to dry the outdoor heat exchanger 12. By this, the moisture on the surface of the outdoor heat exchanger 12 evaporates, and the outdoor heat exchanger 12 is dried. In addition, at time t3 to t4, the control unit 30 can also drive the compressor 11 in a cold air cycle to dry the outdoor heat exchanger 12. In addition, even if the outdoor fan 14 is not driven, the moisture in the outdoor heat exchanger 12 will evaporate due to the natural convection of the outside atmosphere. However, by driving the outdoor fan 14, the moisture in the outdoor heat exchanger 12 becomes easy. evaporation. With this evaporation of water, even if a small amount of salt remains in the outdoor heat exchanger 12, the corrosion of the outdoor heat exchanger 12 caused by the salt dissolved in the water can be suppressed.

In addition, in the example of FIG. 6, during the drying of the outdoor heat exchanger 12, the compressor 11 and the indoor fan 17 are in a stopped state. In addition, the four-way valve 18 and the expansion valve 15 are maintained in the state when the outdoor heat exchanger 12 is thawed.

Fig. 7 is a Mollier chart during normal heating operation and during freezing and cleaning of outdoor heat exchangers (refer to Fig. 1 as appropriate). In addition, the horizontal axis of Fig. 7 is the specific enthalpy of the refrigerant, and the vertical axis of Fig. 7 is the pressure of the refrigerant. The saturated vapor line α shown in Fig. 7 is the boundary line between the gas phase and the gas-liquid phase in the state of the refrigerant. The saturated liquid line β is the boundary line between the liquid phase and the gas-liquid phase in the state of refrigerant. In addition, in the area surrounded by the saturated vapor line α and the saturated liquid line β, the refrigerant is in a two-phase gas-liquid state. In addition, the boundary point between the saturated vapor line α and the saturated liquid line β is referred to as the critical point γ.

A dotted chain line M in the trapezoid shape shown in Fig. 7 is a Mollier chart during normal heating operation. On the other hand, the solid line N of the trapezoid shape shown in FIG. 7 is a Mollier chart of the outdoor heat exchanger 12 during freezing and washing. As shown in Figure 7, during normal heating operation, the refrigerant is compressed (state Ma→Mb), condensation (state Mb→Mc), expansion (state Mc→Md), and evaporation (state Md→Ma). The refrigeration cycle is carried out.

On the other hand, during the freezing and washing of the outdoor heat exchanger 12, as described above, the expansion valve 15 is always contracted to the opening degree u1 (refer to FIG. 6). As a result, the pressure of the refrigerant expanded at the expansion valve 15 (state Nd) becomes lower than that during normal heating operation (state Md), and with this, the temperature of the refrigerant also becomes lower. By this, the lower part P2 (refer to FIG. 3) of the outdoor heat exchanger 12 is frozen.

In addition, since the temperature difference between the refrigerant below the freezing point and the outside atmosphere circulating at the lower part P2 (see FIG. 3) of the outdoor heat exchanger 12 is large, the heat exchange system between the refrigerant and the outside atmosphere becomes easy. conduct. Furthermore, by constantly shrinking the expansion valve 15 to the opening degree u1 (refer to FIG. 6), the circulation amount of the refrigerant per unit time is reduced compared to the normal heating operation. As a result, at the lower portion P2 of the outdoor heat exchanger 12 (especially near the lower end), a low-temperature gas-liquid two-phase refrigerant flows, for example, between the pipe kc (refer to FIG. 3) and the pipe kh (refer to FIG. 3) Nearby, the state of the refrigerant changes to a gas phase (state Ne in Fig. 7).

In this way, in the process of freezing and cleaning the outdoor heat exchanger 12 (in the first process), at least a part of the lower part P2 (refer to FIG. 3) of the outdoor heat exchanger 12 is in the state of a gas-liquid refrigerant. Two-phase, at least a part of the upper part P1 (refer to FIG. 3) of the outdoor heat exchanger 12 is in a state of a refrigerant in a gaseous phase.

Furthermore, as it goes to the downstream side of the pipe kc (refer to FIG. 3) and the pipe kh (refer to FIG. 3), the degree of superheat of the refrigerant becomes higher due to heat exchange with the outside atmosphere (state Na in FIG. 7). For example, in the vicinity of the downstream end of the outdoor heat exchanger 12, the temperature of the refrigerant becomes approximately equal to the outside atmosphere. If such a refrigerant with a high degree of superheating is sucked into the compressor 11, the refrigerant discharged from the compressor 11 (state Nb) will have a higher degree of superheating during heating operation (state Mb). And higher (also refer to the specific enthalpy difference ΔH1).

Therefore, in order to ensure the reliability of the compressor 11, it is desirable to perform the following control. That is, in the freezing and washing process of the outdoor heat exchanger 12 (during the first process), the control unit 30, preferably, when the temperature on the discharge side of the compressor 11 becomes higher than the second specific temperature At this time, the rotation speed of the indoor fan 17 is increased more than that at the beginning of the freezing and washing process.

In addition, the aforementioned "second specific temperature" is a threshold value that serves as a criterion for determining whether or not to increase the rotation speed of the indoor fan 17 during freezing washing, and is set in advance. In this way, by increasing the rotation speed of the indoor fan 17, the heat exchange system at the indoor heat exchanger 16 is promoted. As a result, since the discharge pressure and the discharge temperature of the compressor 11 are lowered, the excessive temperature rise of the compressor 11 is suppressed, and the reliability of the compressor 11 can be ensured.

In addition, during the freezing and washing of the outdoor heat exchanger 12, since the expansion valve 15 is constantly contracted to the opening degree u1 (refer to FIG. 6), the flow rate of the refrigerant at the indoor heat exchanger 16 is also reduced. As a result, in the vicinity of the downstream end of the indoor heat exchanger 16 (state Nc in FIG. 7), the temperature of the refrigerant is lowered to near room temperature, and the state of the refrigerant is mostly in the liquid phase. The refrigerant that has been condensed in this manner is decompressed at the expansion valve 15 (state Nd). After that, the low-temperature and low-pressure refrigerant decompressed at the expansion valve 15 is guided to the outdoor heat exchanger 12. As described above, the lower part P2 of the outdoor heat exchanger 12 (refer to FIG. 3) is Was frozen.

<Effect> According to the first embodiment, the control unit 30 freezes the lower part P2 (refer to FIG. 3) of the outdoor heat exchanger 12 to flush out the salt and the like in the lower part P2. As a result, the outdoor heat exchanger 12 can be brought into a clean state. In particular, when the outdoor unit Uo is installed near the coast where salt damage is likely to occur, corrosion may occur at the lower part P2 of the outdoor heat exchanger 12 in many cases. By the aforementioned freezing and washing, the corrosion of the lower part P2 of the outdoor heat exchanger 12 can be suppressed.

In addition, suppose that when only the upper part P1 of the outdoor heat exchanger 12 is frozen, as the water flows down through the fin f (refer to FIG. 3) with subsequent thawing, it will become high-concentration salt water. As a result, there is a possibility that salt will remain in the lower part P2. On the other hand, if the lower part P2 of the outdoor heat exchanger 12 is frozen as in the first embodiment, the high-concentration salt water does not flow down from the upper part P1, so the salt content of the lower part P2 can be adjusted appropriately. Rinse it off.

In addition, according to the first embodiment, the lower part P2 (refer to FIG. 3) of the outdoor heat exchanger 12 is frozen. On the other hand, it is not necessary to freeze the upper part P1 (refer to FIG. 3) of the outdoor heat exchanger 12 . Therefore, compared to the case where both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 are frozen, the time for the warm air to be blown out into the room is shortened, and the increase in the indoor temperature can be suppressed.

In addition, the freezing washing of the outdoor heat exchanger 12 is completely different from the freezing washing of the indoor heat exchanger 16 (not specifically explained in the first embodiment). This is because as the outdoor heat exchanger 12 freezes, the indoor heat exchanger 16 functions as a condenser, and the warm air is blown out from the indoor unit Ui. In the freezing and washing of the indoor heat exchanger 16, even if warm air is blown from the outdoor unit Uo, it will not cause a particular problem. However, in the freezing and washing of the outdoor heat exchanger 12, if it is from the indoor unit Ui And if there is warm wind, it may cause discomfort to the user.

Therefore, in the first embodiment, taking into account the comfort for the user, the outdoor heat exchanger 12 can be frozen and cleaned in a short time, and the lower part P2 is frozen, and the The time for the indoor unit Ui to blow the warm wind becomes shorter. This view is related to the freezing and cleaning of the outdoor heat exchanger 12, and is the view that the inventors of the present invention have discovered for the first time in their diligent review.

In addition, after the outdoor heat exchanger 12 freezes, the control unit 30 increases the opening of the expansion valve 15 and flows a high-temperature refrigerant into the outdoor heat exchanger 12. Thereby, the thawing system of frost or ice in the lower part P2 (refer to FIG. 3) of the outdoor heat exchanger 12 becomes easy to progress. In addition, after the outdoor heat exchanger 12 is thawed, the control unit 30 drives the outdoor fan 14 to dry the outdoor heat exchanger 12. By this, even when a small amount of salt remains in the outdoor heat exchanger 12, the corrosion of the outdoor heat exchanger 12 caused by the salt dissolved in the water can be suppressed. In addition, the control unit 30 may also be configured to freeze the lower part P2 of the outdoor heat exchanger 12 in the first process, when the indoor temperature becomes the first specific temperature (for example, 32°C) or higher, or This is when the indoor temperature rises above a specific temperature (for example, 10°C) from the start of the first treatment, the first treatment is ended. By this, it is possible to reduce the user's discomfort caused by the increase in indoor temperature. In addition, the aforementioned "first specific temperature", etc., are threshold values that serve as a criterion for determining whether or not to end (suspend) the first process, and are set in advance.

＜＜The second embodiment＞＞ The second embodiment changes the manner in which the freezing of the outdoor heat exchanger 12 proceeds based on the indoor temperature, and is different from the first embodiment in this point. In addition, the other structures (the structure of the air conditioner 100, etc.: refer to FIGS. 1 to 4) are the same as those of the first embodiment. Therefore, the description will be given for the parts that are different from the first embodiment, and the description for the overlapping parts will be omitted.

FIG. 8 is a flowchart of the freezing and washing process related to the outdoor heat exchanger 12 (refer to FIG. 1 and FIG. 4 as appropriate). In addition, since the processing of step S201 is the same as that of step S101 in the first embodiment (refer to FIG. 5), the description thereof will be omitted. In step S201, when the freezing and washing start condition of the outdoor heat exchanger 12 is satisfied (S201, Yes), the processing of the control unit 30 proceeds to step S202.

In step S202, the control unit 30 determines whether the indoor temperature T detected by the indoor temperature sensor 22 (see FIG. 4) is equal to or higher than the third specific temperature T3. The aforementioned "third specific temperature T3" is a threshold value that serves as a criterion for determining whether to freeze the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 (S204), and is set in advance.

In step S202, when the room temperature T is equal to or higher than the third specific temperature T3 (step S202: Yes), the processing of the control unit 30 proceeds to step S203. In step S203, the control unit 30 freezes the lower part P2 (see FIG. 3) of the outdoor heat exchanger 12 as a process of freezing and washing the outdoor heat exchanger 12 (first process). By this, compared to the case where the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 are frozen (S204), the time required for the freezing and washing of the outdoor heat exchanger 12 can be shortened. Therefore, in the freezing washing of the outdoor heat exchanger 12, it is possible to shorten the time for blowing warm air into a relatively high-temperature room.

In addition, preferably, the expansion valve 15 is opened when the lower part P2 of the outdoor heat exchanger 12 is frozen (S203), compared to the case where the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 are frozen (S204). The degree system is smaller. By fully shrinking the expansion valve 15 in this way, the temperature of the refrigerant circulating in the piping k1 (refer to FIG. 1) downstream of the expansion valve 15 becomes very low, and the circulation amount of the refrigerant Fewer. As a result, the lower part P2 (particularly near the lower end) of the outdoor heat exchanger 12 freezes, and on the other hand, the upper part P1 (particularly near the upper end) flows a normal temperature gas refrigerant.

In addition, it is more desirable that compared to the case where the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 are frozen (S204), the lower part of the outdoor heat exchanger 12 is frozen and washed (the first process). When P2 is frozen (S203), the time for keeping the temperature of the outdoor heat exchanger 12 below the freezing point is shorter. With this, during freezing of the lower part P2 of the outdoor heat exchanger 12, the time for blowing warm air to the room can be shortened.

In addition, although the illustration is omitted in FIG. 8, the system may also be configured such that after freezing the lower portion P2 of the outdoor heat exchanger 12 at step S203, the control is performed in the same manner as in the first embodiment. Part 30, thawing and drying the outdoor heat exchanger 12 in sequence. After the process of step S203 is performed, the control unit 30 ends a series of processes related to the freezing and washing of the outdoor heat exchanger 12 (END).

Furthermore, in step S202, when the room temperature T is less than the third specific temperature T3 (step S202: No), the processing of the control unit 30 proceeds to step S204. In step S204, the control unit 30 freezes both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12. As described above, compared to the case of freezing the lower part P2 of the outdoor heat exchanger 12 (S203), the expansion valve 15 is used in the case of freezing both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 (S204). The opening degree is larger, but, other than that, it is the same as the processing of step S204 (also refer to "freezing" in FIG. 6).

In addition, in the matter of "freezing both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12", in addition to the aforementioned matter of freezing the entire upper part P1 and the lower part P2, it also includes the upper part P1 and the lower part P2. At least part of the frozen matters.

Next, in step S205, the control unit 30 defrosts both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12. For example, the control unit 30 is the same as the "thawing" in FIG. By this, the salt and the like of the outdoor heat exchanger 12 are washed away, and the entire system of the outdoor heat exchanger 12 is washed. In addition, at the time of thawing in step S205, the control unit 30 can stop the compressor 11 and the outdoor fan 14 and maintain the opening degree of the expansion valve 15 to be the same as that during freezing. Even with this treatment, the frost or ice of the outdoor heat exchanger 12 is naturally melted by the heat exchange with the outside atmosphere.

Next, in step S206, the control unit 30 freezes the lower part P2 of the outdoor heat exchanger 12. In addition, the control content of step S206 is the same as step S203 (also refer to "freezing" in FIG. 6), so the description is omitted.

In this way, when the indoor temperature T is less than the third specific temperature T3 (S202, No), the control unit 30 causes the outdoor heat exchanger 12 to function as an evaporator and causes the outdoor heat exchanger 12 to function as an evaporator. Both the upper part P1 and the lower part P2 are frozen (S204). After that, after freezing both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 (S204), the control unit 30 defrosts both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 (S205), and the After thawing, the first process of freezing the lower part P2 of the outdoor heat exchanger 12 is performed (S206). By this, even after the freezing of the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 (S204, S205), a little salt remains at the lower part P2, and this salt can be washed away.

In addition, since the indoor temperature T is less than the third specific temperature T3 (S202, No), the time required for freezing washing (S204 to S206) of the outdoor heat exchanger 12 is relatively long. There is almost no problem of unpleasant feeling caused by the blowing of warm air in the room.

In addition, although the illustration is omitted in FIG. 8, the system may also be configured such that after the lower portion P2 of the outdoor heat exchanger 12 is frozen at step S206, the control unit 30 sequentially performs outdoor heat exchange The thawing and drying of the container 12 (refer to Figure 6). After the process of step S206 is performed, the control unit 30 ends a series of processes related to the freezing and washing of the outdoor heat exchanger 12 (END).

<Effect> According to the second embodiment, when the indoor temperature T is higher than the third specific temperature T3 (S202, Yes), the control unit 30 freezes the lower part P2 of the outdoor heat exchanger 12 (S203). By this, it is possible to wash away the salt and the like attached to the lower part P2 of the outdoor heat exchanger 12 in a short time. In addition, it is possible to shorten the time for blowing warm air into a relatively high-temperature room.

On the other hand, when the indoor temperature T is less than the third specific temperature T3 (S202, No), the control unit 30 freezes both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12, and then Defrost (S204, S205), and further freeze the lower part P2 of the outdoor heat exchanger 12 (S206). With this, the outdoor heat exchanger 12 can be cleaned as a whole. In addition, even if it is “frozen and washed with the upper part P1 and the lower part P2 of the outdoor heat exchanger 12, the water system with a high salt concentration flows through the surface of the lower part P2 at the outdoor heat exchanger 12, and here When the salt remains in the lower part P2", the salt is also washed away by the processing of step S206. As a result, compared to the case where the freezing washing of the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 is repeated twice, the time required for the freezing washing can be shortened.

＜＜Modifications＞＞ In the above, although the air conditioner 100 of the present invention has been described with respect to each embodiment, the present invention is not limited to these descriptions, and various modifications can be made. For example, in each embodiment, although the outdoor heat exchanger 12 is provided with the fins fa and fb (refer to FIG. 3) arranged side by side in the left-right direction, the description has been made, but the system is not limited to this. In other words, the outdoor heat exchanger 12A may be constructed like FIG. 9.

Fig. 9 is an explanatory diagram showing the pass of the outdoor heat exchanger 12A of the air conditioner according to the modification. In the example of FIG. 9, the outdoor heat exchanger 12A is equipped with the fin f of a longitudinally long rectangular shape. However, in the front of the paper in Fig. 9-the deep prescription upward, plural fins f are arranged at specific intervals. On the other hand, during the freezing of the outdoor heat exchanger 12A (during the heating cycle), the refrigerant flows into the lower part P2 of the outdoor heat exchanger 12A via the pipe k1. By this, the lower part P2 of the outdoor heat exchanger 12A (especially the vicinity of the lower end) is frozen.

The refrigerant circulating in the lower part P2 of the outdoor heat exchanger 12A passes through the pipe kp and the distributor w4 in this order, and is branched to the pipes kq and kr. The refrigerant flowing through one of the pipes kq circulates through the upper portion P1 of the outdoor heat exchanger 12A, and then is guided to the suction side of the compressor 11 (see FIG. 1) through the pipe ks. The refrigerant circulating in the pipe kr on the other side circulates in the area including the intermediate position R of the outdoor heat exchanger 12A, and then is guided to the suction side of the compressor 11 (see FIG. 1) through the pipe kt Place. In addition, although not shown, the refrigerant circulating in the pipe kt and the pipe ks is merged and guided to the suction side of the compressor 11 (refer to FIG. 1). Even with this structure, the same effects as in the respective embodiments can be exerted.

In addition, the passages of the outdoor heat exchangers 12 and 12A described in FIG. 3 or FIG. 9 are only an example, and the aforementioned passages may be appropriately changed. In addition, the outdoor heat exchanger may be provided with three or more rows of fins (not shown) arranged side by side in the left-right direction.

In addition, in the first embodiment, although the process of freezing the lower portion P2 of the outdoor heat exchanger 12 (S102 in FIG. 5) has been described, the system is not limited to this. That is, it is also possible to replace the processing of step S102 shown in FIG. 5 to condense the lower part P2 of the indoor heat exchanger 12. In this way, when dew condensation occurs at the lower part P2 of the outdoor heat exchanger 12, the control unit 30 makes the temperature of the outdoor heat exchanger 12 lower than the dew point of the outside atmosphere and higher than the specified freezing temperature The method is to adjust the opening degree of the expansion valve 15 and make this state continue for a specific time. The aforementioned "freezing temperature" refers to the temperature at which moisture contained in the air starts to freeze at the outdoor heat exchanger 12 when the temperature of the outdoor heat exchanger 12 is gradually reduced. After condensing the lower part P2 of the outdoor heat exchanger 12 in this way, the control unit 30 may also drive the outdoor fan 14 to dry the outdoor heat exchanger 12.

In addition, compared to the case where the lower part P2 of the outdoor heat exchanger 12 is "frozen", the opening degree of the expansion valve 15 is greater in the case of "condensation". In the case of ", the control content (refer to Figure 6) is the same. In addition, the processing of steps S203, S204, and S206 in the second embodiment (refer to FIG. 8) can be said to be the same.

In addition, in the first embodiment, the control unit 30 rotates the outdoor fan 14 at a lower speed than during normal air-conditioning operation during the freezing of the outdoor heat exchanger 12 (during the first process). , And made an explanation, but the department is not limited to this. For example, during freezing of the outdoor heat exchanger 12 (during the first process), the control unit 30 may be configured to maintain the outdoor fan 14 in a stopped state. By performing this treatment, even in a high temperature environment, the frost or ice of the outdoor heat exchanger 12 becomes easy to grow. In addition, it can be said that the same applies to the second embodiment.

In addition, in the first embodiment, although it is for the case where the temperature on the discharge side of the compressor 11 becomes higher than the second specific temperature during freezing of the lower part P2 of the outdoor heat exchanger 12 (during the first process) The control unit 30 has been described as a process of increasing the rotation speed of the indoor fan 17, but it is not limited to this. For example, it may be configured such that during freezing of the lower part P2 of the outdoor heat exchanger 12 (during the first process), when the temperature of the indoor heat exchanger 16 (condenser) becomes equal to or higher than the second specific temperature, The control unit 30 increases the rotation speed of the indoor fan 17. Even with this kind of processing, the temperature rise of the compressor 11 can be suppressed. In addition, in the aforementioned control, the temperature of the discharge side of the compressor 11 and the temperature of the indoor heat exchanger 16 may be combined. That is, it may be configured such that during the freezing of the lower part P2 of the outdoor heat exchanger 12 (during the first process), the temperature of the discharge side of the compressor 11 and/or the temperature of the indoor heat exchanger 16 becomes When the temperature is equal to or higher than the second specific temperature, the control unit 30 increases the rotation speed of the indoor fan 17.

In addition, in the second embodiment, although the process of causing the control unit 30 to change the freezing method of the outdoor heat exchanger 12 based on the indoor temperature (S202 in FIG. 8) has been described, it is not Was limited to this. For example, regarding step S202 in FIG. 8, the outdoor temperature may be used instead of the indoor temperature, and the indoor temperature and the outdoor temperature may also be combined. That is, the system may also be configured such that when the indoor temperature and/or the outdoor temperature becomes equal to or higher than the third specific temperature, the control unit 30 performs the first process of freezing the lower part P2 of the outdoor heat exchanger 12 (Figure 8 of S203). In addition, the system may also be configured such that when the indoor temperature and/or the outdoor temperature is less than the third specific temperature, the control unit 30 freezes both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 (Fig. 8 S204).

In addition, it may be configured such that the control unit 30 performs freezing of both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12 regardless of the indoor temperature or the outdoor temperature. That is, the system may also be configured as: the control unit 30 makes the outdoor heat exchanger 12 function as an evaporator, and after freezing both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12, heat the outdoor Both the upper part P1 and the lower part P2 of the heat exchanger 12 are thawed, and after the thawing, a process of freezing the lower part P2 of the outdoor heat exchanger 12 is performed. By this, the outdoor heat exchanger 12 can be cleaned as a whole, and further, the salt and the like in the lower part P2 of the outdoor heat exchanger 12 can be washed away. In addition, when performing the aforementioned "thawing", the control unit 30 can increase the opening of the expansion valve 15 and can also maintain the opening of the expansion valve 15 during freezing. Stop the compressor 11 and other machines.

In addition, for example, the control unit 30 may be configured to freeze only the lower part P2 of the outdoor heat exchanger 12, and on the other hand, it does not freeze the upper part P1 of the outdoor heat exchanger 12. In addition, the control unit 30 may be configured to dry the outdoor heat exchanger 12 after repeatedly freezing and thawing the lower part P2 of the outdoor heat exchanger 12. In addition, the system may also be configured such that the control unit 30 does not take into account the increase in indoor temperature, but after repeatedly freezing and thawing the upper part P1 and the lower part P2 of the outdoor heat exchanger 12, The outdoor heat exchanger 12 is dried. Even through the aforementioned processes, the outdoor heat exchanger 12 can be brought into a clean state.

In addition, the system may also be configured such that when the indoor temperature is higher than the fourth specific temperature, the control unit 30 does not freeze the lower part P2 of the outdoor heat exchanger 12 or the upper part P1 of the outdoor heat exchanger 12 Freezing of the lower part P2. In addition, the aforementioned "fourth specific temperature" is a threshold value for determining whether or not to freeze the outdoor heat exchanger 12, and is set as a comparison with the aforementioned third specific temperature T3 (S202 in FIG. 8) Higher values are set in advance. By this, it is possible to prevent a situation in which warm air is blown from the indoor unit Ui when the indoor temperature is quite high. In addition, in the aforementioned treatment, the outdoor temperature may be used instead of the indoor temperature, and both the indoor temperature and the outdoor temperature may also be used. That is, the system may also be configured such that when the indoor temperature and/or the outdoor temperature becomes higher than the fourth specific temperature, the control unit 30 does not perform the freezing of the outdoor heat exchanger 12 including the aforementioned first process. (Or condensation).

In addition, the system may also be configured such that when the stop button (not shown) of the remote controller 40 is pressed during the freezing (or condensation) processing of the outdoor heat exchanger 12, the control unit 30 The aforementioned processing is suspended. For example, it may be configured such that when the stop button (not shown) of the remote controller 40 is pressed during the first process of freezing or dew condensation on the lower part P2 of the outdoor heat exchanger 12, the control unit 30 is to discontinue the aforementioned first treatment. By this, it is possible to reflect the intention of the user who "stops the freezing and washing of the outdoor heat exchanger 12 so that the warm air is not blown out from the indoor unit Ui".

In addition, the system may also be configured such that when a specific air-conditioning operation start command is received from the remote controller 40 during the freezing (or condensation) processing of the outdoor heat exchanger 12, the control unit 30 is After the aforementioned processing is terminated, the specific air-conditioning operation is started. For example, it may be configured such that when a specific air-conditioning operation start command is received from the remote controller 40 in the first process of freezing or dew condensation on the lower part P2 of the outdoor heat exchanger 12, the control unit 30, After stopping the aforementioned first process, the specific air-conditioning operation is started. By this, it is possible to reflect the user's intention "want to start a specific air-conditioning operation such as cooling operation or heating operation".

In addition, the system can also be configured such that the setting of "freezing (or condensation) of the outdoor heat exchanger 12 in each specific period" and "no outdoor heat exchange can be performed by the operation of the remote controller 40". Switch to other settings of "Freezing (or condensation) of device 12". For example, the system may also be configured such that by operating the remote controller 40, the setting of "the first process of freezing or condensation of the lower part P2 of the outdoor heat exchanger 12 in each specific period" can be set and "combined Switch to other settings of "Do not perform the aforementioned first processing". With this, for example, when the outdoor unit Uo is installed in an area near the coast where salt damage is prone to occur, the operation of the remote controller 40 by the user can make it possible to perform outdoor outdoor operations on a regular basis. The freezing and washing method of the heat exchanger 12 is set. On the other hand, in areas where there is almost no problem of salt damage, the operation of the remote controller 40 by the user can also adopt a setting that does not perform freezing and washing of the outdoor heat exchanger 12.

In addition, the system may also be configured to control when the temperature in the vicinity of the lower part P2 of the outdoor heat exchanger 12 is below the freezing point even after a certain period of time has elapsed since the freezing of the lower part P2 of the outdoor heat exchanger 12 The part 30 makes the outdoor heat exchanger 12 function as a condenser. That is, when the frost or ice of the outdoor heat exchanger 12 is difficult to melt, the control unit 30 can also circulate the refrigerant through the cold air circulation and actively defrost the outdoor heat exchanger 12.

Moreover, it is also possible to install a drainage-inducing part (not shown) at the lower part P2 of the outdoor heat exchanger 12, and it may be comprised so that moisture may not be kept in the lower part P2 of the outdoor heat exchanger 12.

In addition, the system may also be configured such that when moisture is retained at the lower portion P2 of the outdoor heat exchanger 12, vibration caused by the driving of the compressor 11, the outdoor fan 14, or both , To remove the moisture held at the lower part P2 of the outdoor heat exchanger 12.

Moreover, it is also possible to apply a specific water repellent treatment to the outdoor heat exchanger 12, and it is comprised so that water may not hold|maintain in the lower part P2 of the outdoor heat exchanger 12.

In addition, it may be configured such that the control unit 30 performs the first process of freezing and washing the outdoor heat exchanger 12, and performs the second process of rotating the outdoor fan 14 in the reverse direction while the normal air-conditioning operation is stopped. handle. For example, it may be configured to perform the second process after the normal air-conditioning operation ends (the end of the normal air-conditioning operation is set as the start condition of the second process). In addition, in a normal air-conditioning operation, the outdoor fan 14 rotates forward, and air flows so as to be drawn into the outdoor fan 14 from the outdoor heat exchanger 12. On the other hand, in the second process, the outdoor fan 14 is rotated in the reverse direction, and the air is sent from the outdoor fan 14 to the outdoor heat exchanger 12. By this, the relatively large dust attached to the outdoor heat exchanger 12 is removed. In this way, the larger dust attached to the outdoor heat exchanger 12 due to the operation of the air conditioner is removed by the second process in which the outdoor fan 14 is reversely rotated, and the smaller dust and salt are removed. The outdoor heat exchanger 12 can be frozen and cleaned.

The second process of causing the outdoor fan 14 to rotate in the reverse direction does not change the indoor environment. Therefore, it may be configured to be executed every time the normal air-conditioning operation ends. On the other hand, the process of freezing and washing the outdoor heat exchanger 12 increases the indoor temperature. Therefore, it can also be configured to start and end the normal air-conditioning operation several times. , The control unit 30 is caused to perform the first process of freezing the lower part P2 of the outdoor heat exchanger 12 once. In addition, since corrosion caused by salt damage, it will progress with the passage of time regardless of whether the air conditioner is running or not. Therefore, it is ideal to perform the process every few weeks or every few months. The first process is performed by freezing and washing the outdoor heat exchanger 12 periodically.

In addition, in each embodiment, although it is for the first process of freezing the lower part P2 of the outdoor heat exchanger 12, when the indoor temperature becomes equal to or higher than the first specific temperature, or when the first process When the indoor temperature rises above a certain temperature from the beginning, the structure of "ending the freezing of the outdoor heat exchanger 12" is explained, but the system is not limited to this. The system can also be configured to freeze both the upper part P1 and the lower part P2 of the outdoor heat exchanger 12. In freezing, when the indoor temperature becomes higher than the first specified temperature, or when the indoor temperature becomes higher than the specified temperature When it rises, the control unit 30 ends the freezing of the outdoor heat exchanger 12.

In addition, in each embodiment, the process of "after thawing of the outdoor heat exchanger 12, the control unit 30 drives the outdoor fan 14 at the first rotation speed and dries the outdoor heat exchanger 12" The description, however, the department is not limited to this. For example, the control unit 30 may be configured to temporarily drive the outdoor fan 14 at the second rotation speed during the thawing, drying, or after drying of the outdoor heat exchanger 12. The rotation speed is higher than the first rotation speed and is set in advance. By this, the thawing and drying of the outdoor heat exchanger 12 is promoted. In addition, in each embodiment, as the starting condition for the freezing and washing of the outdoor heat exchanger 12 (S101 in FIG. 5), although the series includes "a specific period has passed since the end of the previous freezing and washing" For example, but the line is not limited to this. For example, the system may also be configured such that a start key (not shown) for freezing and washing of the outdoor heat exchanger 12 is provided at the remote control 40, and when the start key is pressed, the control unit 30 starts Freeze and wash.

In addition, in each embodiment, although the control unit 30 causes the indicator lamp 25 (see FIG. 4) to perform specific lighting or extinguishing during the freezing and cleaning of the outdoor heat exchanger 12" The description, however, the department is not limited to this. For example, it can also be configured to display the content representing that it is freezing and washing on the remote controller 40 or a mobile terminal (not shown).

In addition, in each embodiment, although the air conditioner 100 (refer to FIG. 1) has been described as a configuration in which one expansion valve 15 is provided in the outdoor unit Uo, the system is not limited to this. For example, in addition to the aforementioned expansion valve 15, another expansion valve (not shown) may be installed near the indoor heat exchanger 16 at the pipe k1.

In addition, in each embodiment, although the indoor unit Ui (refer to FIG. 1) and the outdoor unit Uo (refer to FIG. 1) are each provided with one configuration, the system is not limited to this. That is, it is also possible to install a plurality of indoor units connected in parallel. In addition to room air conditioners, various embodiments can also be applied to various air conditioners such as a packaged air conditioner or a composite air conditioner for buildings.

In addition, each embodiment is described in detail in order to explain the present invention easily, and the present invention is not limited to those that include all the structures described. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. In addition, the aforementioned institutions and structures are representative of those deemed necessary for the explanation, and not all institutions and structures are absolutely marked on the product.

100: Air conditioner 11: Compressor 12, 12A: outdoor heat exchanger (evaporator, condenser) 13: Outdoor heat exchanger temperature sensor 14: Outdoor fan 15: Expansion valve 16: Indoor heat exchanger (evaporator, condenser) 17: Indoor fan 18: Four-way valve 19: Accumulator 21: Remote control sending and receiving department 22: Indoor temperature sensor 25: indicator light 26: Outdoor temperature sensor 30: Control Department 40: remote control k1, ka, kb: piping P1: Upper part (upper part of outdoor heat exchanger) P2: Lower part (lower part of outdoor heat exchanger) Q: Refrigerant circuit r: Up and down wind direction board R: middle position Ui: Indoor unit Uo: outdoor unit v: downstream end

[Fig. 1] is a block diagram of the air conditioner according to the first embodiment of the present invention. [Fig. 2] is a perspective view of a state in which the side plates and top plates of the casing of the outdoor unit included in the air conditioner according to the first embodiment of the present invention are removed. [Fig. 3] is an explanatory diagram showing the pass of the outdoor heat exchanger of the air conditioner according to the first embodiment of the present invention. [Fig. 4] is a functional block diagram of the air conditioner according to the first embodiment of the present invention. [Fig. 5] is a flowchart related to the freezing and washing process of the outdoor heat exchanger of the air conditioner according to the first embodiment of the present invention. [Figure 6] is a timing chart showing the states of the compressor, four-way valve, expansion valve, outdoor fan, and indoor fan in the air conditioner according to the first embodiment of the present invention. Fig. 7 is a Mollier chart of the air conditioner according to the first embodiment of the present invention during normal heating operation and during freezing and cleaning of the outdoor heat exchanger. [Fig. 8] is a flowchart related to the freezing and washing process of the outdoor heat exchanger of the air conditioner according to the second embodiment of the present invention. [Fig. 9] is an explanatory diagram showing a pass of an outdoor heat exchanger of an air conditioner according to a modification of the present invention.

100: Air conditioner 11: Compressor 11a: Compressor motor 12: Outdoor heat exchanger (evaporator, condenser) 13: Outdoor heat exchanger temperature sensor 14: Outdoor fan 14a: Outdoor fan motor 15: Expansion valve 16: Indoor heat exchanger (evaporator, condenser) 17: Indoor fan 18: Four-way valve k1: Piping Q: Refrigerant circuit r: Up and down wind direction board Ui: Indoor unit Uo: outdoor unit

Claims (20)

An air conditioner with: The refrigerant circuit has a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; and The control unit controls at least the aforementioned compressor and the aforementioned expansion valve, The control unit performs a first process for freezing or condensation of the lower part of the outdoor heat exchanger. In the first process, at least a part of the lower part of the outdoor heat exchanger is frozen and the outdoor heat exchanger is frozen. At least part of the upper part is not frozen. Such as the air conditioner described in claim 1, in which: The refrigerant decompressed by the expansion valve in the first process is guided to the downstream end of the pipe at the outdoor heat exchanger, and is connected to the lower part of the outdoor heat exchanger. Such as the air conditioner described in claim 1, in which: In the first treatment, at least a part of the lower part of the outdoor heat exchanger is in the state of a two-phase gas-liquid refrigerant, and at least part of the upper part of the outdoor heat exchanger is in a gas-phase state. . Such as the air conditioner described in claim 1, in which: It has an outdoor fan, In normal air-conditioning operation, the outdoor fan rotates positively, and the air flows in a manner of being sucked into the outdoor fan from the outdoor heat exchanger. The control unit performs the second process of causing the outdoor fan to reversely rotate during the stop of the normal air-conditioning operation. Such as the air conditioner described in claim 4, in which: The control unit periodically performs the first processing, and performs the second processing after the normal air-conditioning operation ends. Such as the air conditioner described in claim 1, in which: It has an outdoor fan, In the first process, the control unit rotates the outdoor fan at a lower speed than during normal air-conditioning operation, or maintains the outdoor fan in a stopped state. Such as the air conditioner described in claim 1, in which: It has an indoor fan, In the first processing, the control unit causes the indoor fan to rotate at a higher speed than the minimum rotation speed during normal air-conditioning operation. Such as the air conditioner described in claim 1, in which: The system is equipped with: up and down wind direction board, which adjusts the wind direction of the air blown from the indoor unit in the up and down direction, In the above-mentioned control unit, in the above-mentioned first process, the above-mentioned up-and-down wind direction plate is set to be more upward than the horizontal direction. Such as the air conditioner described in claim 1, in which: It has an indoor fan, In the first process, the control unit increases the rotation speed of the indoor fan when the temperature of the discharge side of the compressor and/or the temperature of the indoor heat exchanger becomes equal to or higher than the second specific temperature . Such as the air conditioner described in claim 1, in which: The control unit, after freezing the lower part of the outdoor heat exchanger as the first treatment, stops the compressor, and further sets the opening of the expansion valve to be larger than that during the first treatment, The aforementioned outdoor heat exchanger is defrosted. Such as the air conditioner described in claim 10, in which: It has an outdoor fan, The control unit drives the outdoor fan at a first rotation speed after thawing the outdoor heat exchanger to dry the outdoor heat exchanger. Such as the air conditioner described in claim 11, in which: The control unit temporarily drives the outdoor fan at the second rotation speed during thawing, drying, or after drying of the outdoor heat exchanger, and The aforementioned second rotation speed is higher than the aforementioned first rotation speed. Such as the air conditioner described in claim 1, in which: The control unit, after making the outdoor heat exchanger function as an evaporator and freezing both the upper and lower parts of the outdoor heat exchanger, defrosts both the upper and lower parts of the outdoor heat exchanger, and After this thawing, the aforementioned first treatment is performed. Such as the air conditioner described in claim 1, which includes: The indoor temperature sensor detects the indoor temperature; and The outdoor temperature sensor detects the outdoor temperature, The aforementioned control unit is When the indoor temperature and/or outdoor temperature is above the third specific temperature, perform the first treatment described above, When the indoor temperature and/or the outdoor temperature are less than the third specific temperature, the outdoor heat exchanger is made to function as an evaporator, and both the upper and lower parts of the outdoor heat exchanger are frozen. Such as the air conditioner described in claim 14, in which: The aforementioned control unit does not perform the freezing of the aforementioned outdoor heat exchanger including the aforementioned first treatment when the indoor temperature and/or the outdoor temperature are above the fourth specific temperature. The aforementioned fourth specific temperature is higher than the aforementioned third specific temperature. Such as the air conditioner described in claim 1, in which: When the stop key of the remote controller is pressed during the first processing, the control unit suspends the first processing. Such as the air conditioner described in claim 1, in which: When the control unit receives a command to start a specific air-conditioning operation from a remote controller in the first process, the specific air-conditioning operation is started after the first process is stopped. Such as the air conditioner described in claim 1, in which: It is possible to switch between the setting of performing the first process and the other setting of not performing the first process in each specific period by the operation of the remote controller. An air conditioner with: The refrigerant circuit has a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; and The indoor temperature sensor detects the indoor temperature; and The control unit controls at least the aforementioned compressor and the aforementioned expansion valve, The control unit performs a first process to freeze or condense the lower part of the outdoor heat exchanger. In the first process, when the indoor temperature becomes equal to or higher than the first specific temperature, or from the first process 1 When the indoor temperature rises above a certain temperature from the start of the treatment, the first treatment is terminated. An air conditioner with: The refrigerant circuit has a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; and The outdoor heat exchanger temperature sensor detects the temperature of the aforementioned outdoor heat exchanger; and The control unit controls at least the aforementioned compressor and the aforementioned expansion valve, The control unit performs the first process to freeze or condense the lower part of the outdoor heat exchanger, Compared with the case of freezing both the upper part and the lower part of the outdoor heat exchanger, the temperature of the outdoor heat exchanger is maintained when the lower part of the outdoor heat exchanger is frozen as the first treatment. The time below freezing is shorter.

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