JP2005049002A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: In an air conditioner, there are problems that a conventional outdoor unit anti-freezing method cannot be heated sufficiently, a power consumption is greatly increased, or a heating capacity is lowered.
In the present invention, a compressor 111, a four-way valve 112, an outdoor heat exchanger 102, a bottom plate heater 203, an outer expansion valve 213, an inner expansion valve 214, and an indoor heat exchanger 115 are configured. Further, a regulating valve 219 is provided in the bypass pipe 217, and thermistors 216 and 218, which are temperature detecting means, are provided at the entrance and exit of the bottom plate heater 203. The outer expansion valve 213, the inner expansion valve 214, and the adjustment valve 219 are adjusted in accordance with the operating state, and the heat absorption / release state of the bottom plate heater 203 is controlled.
[Selection] Figure 3

Description

  The present invention is an air conditioner that performs heating using a vapor compression heat pump cycle, prevents freezing of drain water generated in an outdoor heat exchanger, and is highly reliable even if heating operation is continued for a long time in a cold district or the like. It is related with the air conditioner from which the property is acquired.

  Conventionally, in a vapor compression type air conditioner, when a heating operation is performed, an outdoor heat exchanger becomes an evaporator, and condensation and frost formation occur. When the outside air temperature becomes low, the drainage after defrosting freezes and grows and may cause operational troubles such as outdoor fan lock.

  As a method for solving this problem by heating, a method using a heater is general and easy.

  As a method of suppressing power consumption and preventing freezing, the heating element of the power supply unit is arranged near the dew pan of the outdoor heat exchanger and heated, the method using a heat pipe, and the discharge of the compressor There are a method using an oil return pipe from an oil separator and a method using heat of a compressor using a metal heat transfer member (see, for example, Patent Documents 1, 2, 3, and 4).

  Further, as a method of reliably suppressing the growth of ice with less power consumption with respect to the heating amount, there is a method of extracting heat from a heat pump cycle and heating (see Patent Document 5). As shown in FIG. 4, the outdoor unit body 1 is provided with a blower circuit including an outdoor heat exchanger 2, a cross flow fan 3, a stabilizer 4, and an air guider 5, and heating operation at a low outdoor temperature is performed. Since ice sometimes grows from the stabilizer 4 and may come into contact with the cross flow fan 3 to cause a blowing failure, the anti-freezing pipe 6 is provided on the stabilizer 4 to prevent freezing.

The refrigerant discharged from the compressor 7 heats indoor air in the indoor heat exchanger 8, flows into the antifreezing pipe 6 through the first pressure reducing device 9, heats the stabilizer 4, and then the second reduced pressure. Heat is absorbed by the outdoor heat exchanger 2 through the device 10 and returned to the compressor 7.
JP-A-3-213927 JP-A-6-249465 JP-A-7-318108 Japanese Utility Model Publication 2-73573 JP-A-63-254365

  However, in the case of preventing the air blow failure due to the freezing of the outdoor unit, the method using the conventional heater consumes the electric power to be turned to the heating if possible, so that the heating capacity is reduced during the heater operation, and the power consumption is increased. Will be invited. In addition, in the method of using the heat of the conventional power supply unit, heat pipe, oil return pipe from the oil separator, it is difficult to heat the whole amount of the condensed water drainage path, Ice can grow from places where there is insufficient heating.

  Further, in the conventional method using the heat of the heat pump cycle, the antifreeze pipe is always at an intermediate pressure and is always radiating heat during the heating operation. The required heat absorption in the outdoor heat exchanger per capacity increases. In order to increase the amount of heat absorbed by the outdoor heat exchanger, it is necessary to increase the air volume of the outdoor blower or lower the evaporation temperature. It becomes. And there existed a subject that a freezing prevention pipe might be in an endothermic state at the time of air_conditionaing | cooling operation, and the air_conditioning | cooling capability may fall.

  In order to solve the above-mentioned problems, the present invention obtains sufficient anti-freezing performance, has little decrease in heating capacity and increase in power consumption, has no decrease in cooling capacity, and is heated for a long time at a low outside temperature. A highly reliable air conditioner is provided even if the operation is continued.

  In order to solve the above-mentioned conventional problems, the air conditioner of the present invention is provided with a heating means in the lower part of the outdoor heat exchanger or in the drain water drainage path, and the heating means is defrosted from a predetermined time before the start of the defrosting operation. It is operated until a predetermined time after the end of operation. Thereby, while obtaining sufficient freezing prevention performance, the increase in power consumption can be suppressed, without reducing heating performance.

  In the air conditioner of the present invention, the heating means transfers heat from the refrigerant. Thereby, the increase in the power consumption per heating amount can be suppressed rather than using a heater.

  In addition, the air conditioner of the present invention includes a first reduced pressure expansion means and a second reduced pressure expansion means, and the heating means is arranged between the first reduced pressure expansion means and the second reduced pressure expansion means, and according to the operating conditions. The first decompression expansion means and the second decompression expansion means are adjusted so that the refrigerant flowing through the heating means is in a high pressure and heat dissipation state during cooling operation and during the operation of the heating means, and the refrigerant flowing through the heating means is low pressure during the heating operation. Control is performed in an endothermic state or a state in which heat transfer is suppressed at an intermediate pressure. As a result, a decrease in heating capacity and an increase in power consumption are small, and freezing can be prevented without reducing the cooling capacity.

  The air conditioner of the present invention is provided with temperature detecting means at the inlet and outlet of the heating means, and adjusts the first reduced pressure expansion means and the second reduced pressure expansion means according to the output of the temperature detection means. Thereby, the control accuracy of the refrigerant heat absorption / release state in the heating means is improved.

  In addition, the air conditioner of the present invention includes a refrigerant flow rate adjusting unit that bypasses the heating unit and connects the first reduced pressure expansion unit and the second reduced pressure expansion unit to adjust the flow rate of the refrigerant, and the heating unit according to the operation mode. The refrigerant is made to flow by bypassing. Thereby, the loss at the time of controlling to a state with little heat transfer can further be suppressed.

  As is apparent from the above, the air conditioner of the present invention is provided with a heating means in the lower part of the outdoor heat exchanger or in the drain water drainage path, and the heating means is defrosted from the predetermined time before the start of the defrosting operation. The operation is continued until after a predetermined time, and sufficient freezing prevention performance can be obtained and an increase in power consumption can be suppressed without lowering the heating performance. According to this structure, there exists an effect that it is reliable and can perform heating operation more efficient than performing anti-freezing operation continuously.

  Further, in the air conditioner of the present invention, the heating means transmits heat from the refrigerant, and an increase in power consumption per heating amount can be suppressed. According to this configuration, there is an effect that it is possible to perform the heating operation with high reliability and less power consumption than when the anti-freezing operation is performed by the heater.

  In addition, the air conditioner of the present invention includes a first reduced pressure expansion means and a second reduced pressure expansion means, and the heating means is arranged between the first reduced pressure expansion means and the second reduced pressure expansion means, and according to the operating conditions. The first decompression expansion means and the second decompression expansion means are adjusted so that the refrigerant flowing through the heating means is in a high pressure and heat dissipation state during cooling operation and during the operation of the heating means, and the refrigerant flowing through the heating means is low pressure during the heating operation. Control is performed in an endothermic state or in a state in which the heat transfer is suppressed by an intermediate pressure, and the heat transfer can be finely controlled in accordance with the operating conditions. According to this structure, there exists an effect that air conditioning can be performed by efficient operation according to all the driving | running conditions.

  Further, the air conditioner of the present invention is provided with temperature detection means at the inlet and outlet of the heating means, and adjusts the first decompression expansion means and the second decompression expansion means according to the output of the temperature detection means. The heat transfer control accuracy can be improved, such as the heat release state, the heat absorption state, or the heat transfer state. According to this configuration, it is possible to perform optimal control for all driving situations, and there is an effect that air conditioning can be performed with the most efficient operation.

  In addition, the air conditioner of the present invention includes a refrigerant flow rate adjusting unit that bypasses the heating unit and connects the first reduced pressure expansion unit and the second reduced pressure expansion unit to adjust the flow rate of the refrigerant, and the heating unit according to the operation mode. The heat loss in a state where there is little movement of heat can be suppressed. According to this configuration, it is possible to perform optimal control for all operating conditions, and it is possible to perform the most efficient air conditioning with little loss.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, Embodiment 1 of the present invention includes a compressor 111, a four-way valve 112, an outdoor heat exchanger 102, a heater 103 corresponding to a heating means, an expansion valve 113, and an indoor heat exchanger 115. ing. The cycle shown in FIG. 1 is a circuit during de-ice operation or cooling operation.

  In order to discharge condensed water generated in the outdoor heat exchanger 102 by heating operation, the outdoor plate 110 of the outdoor unit 110 has an outdoor heat exchange in the drainage channel 107, the drainage port 105, and the drainage channel 107 that are one step lower than the surroundings. The heat exchanger support part 104 which installs the apparatus 102 is provided. And in order to prevent freezing, the heater 103 for heating the periphery of the baseplate 101 especially the drainage channel 107 is provided. Further, the water channel outlet 108 around the drain port 105 is connected to the drain port 105 by being lowered by one level from the drain channel 107 in order to ensure drainage.

  The heater 103 is a heater formed in a sheet shape so that the entire drainage channel 107 can be efficiently warmed, and power is supplied from the input ends 106a and 106b. In the heater 103, holes are formed in the drainage port 105 and the heat exchanger support 104, and the heater 103 is configured to fit between the outdoor heat exchanger 102 and the drainage channel 107 of the bottom plate 101.

  When the air conditioner continues the heating operation when the outside air temperature is about 0 ° C., the water that has flowed down from the outdoor heat exchanger 102 due to the de-ice operation or the moisture in the air is frozen on the leeward side of the outdoor heat exchanger 102 of the bottom plate 101. If left unattended, it may grow and lock the outdoor fan. In order to prevent this, heating is performed by the heater 103, but if power is always supplied, an increase in power consumption cannot be avoided. In addition, spending power to prevent freezing within a limited power capacity would lead to a reduction in maximum capacity.

  FIG. 2 shows the transition of the current value before and after the de-ice operation during the heating operation under a low outside temperature. The horizontal axis represents time and the vertical axis represents the current value of the apparatus. The main body current value 121 performs heating with the maximum capacity up to the time Ta with the maximum allowable current value Amax as an upper limit. The driving speed of the compressor 111 is reduced from the time Ta, and the four-way valve 112 is switched to perform de-ice. As the de-ice operation proceeds, the current value increases from time Tb, and the compressor 111 is stopped and the four-way valve 112 is switched at time Tc when the outlet temperature of the outdoor heat exchanger 102 reaches a predetermined temperature. Then, during the period from time Td to the heating operation and until the time Te, the driving operation of the compressor 111 is suppressed and the starting operation is performed. Thereafter, the normal operation is returned to and the heating operation is performed with the maximum capacity at the time Tf.

  The main body current value 121 is lower than the maximum allowable current value Amax from the time Ta when the de-ice operation is started to the time Tf when returning to the maximum capacity. During this time, it is possible to supply power to the heater 103. In FIG. 2, if the input of the entire apparatus is allowed to the maximum, it is possible to supply power to the heater 103 according to the pattern of the heater allowable current value 122. Heating is not originally performed during this time period, and power supply to the heater 103 does not lead to a decrease in heating capacity. Furthermore, since a large heating capacity can be obtained during the time when the condensed water flows down, it is possible to efficiently prevent freezing.

  In particular, when the outside air temperature is low and the temperature of the bottom plate 101 is difficult to rise, the main body current value 123, the heater is reduced by reducing the driving speed of the compressor 111 before the de-ice operation start time Ta. If an operation pattern such as the allowable current value 124 is adopted, it is possible to reliably prevent freezing.

(Embodiment 2)
As shown in FIG. 3, the second embodiment of the present invention includes a compressor 111, a four-way valve 112, an outdoor heat exchanger 102, a bottom plate heater 203 corresponding to a heating means, and an outer expansion valve corresponding to a first reduced pressure expansion means. 213, the inner expansion valve 214 corresponding to the second decompression expansion means, and the indoor heat exchanger 115. Further, the bypass pipe 217 is provided with an adjustment valve 219 corresponding to a flow rate adjusting means, and thermistors 216 and 218 as temperature detecting means are provided at the entrance and exit of the bottom plate heater 203. The cycle shown in FIG. 3 is a circuit during the de-ice operation or the cooling operation.

  As in Embodiment 1, the bottom plate 101 of the outdoor unit 110 discharges condensed water generated in the outdoor heat exchanger 102 by heating operation, so that the drainage channel 107, the drainage port 105, and the drainage channel that are one step lower than the surroundings are discharged. A heat exchanger support 104 for installing the outdoor heat exchanger 102 is provided in 107. In order to prevent freezing, a bottom plate heater 203 for heating the periphery of the bottom plate 101, particularly the drainage channel 107, is provided. Further, the water channel outlet 108 around the drain port 105 is connected to the drain port 105 by being lowered by one level from the drain channel 107 in order to ensure drainage.

  The bottom plate heater 203 is formed in a shape along the drainage channel 107 so that the entire drainage channel 107 can be efficiently heated, and is accommodated between the outdoor heat exchanger 102 and the drainage channel 107 of the bottom plate 101. ing.

  During the heating operation, high-temperature and high-pressure refrigerant is discharged from the compressor 111, passes through the four-way valve 112, dissipates heat and is condensed in the indoor heat exchanger 115, and then reaches the inner expansion valve 214. From the inner expansion valve, through the bottom plate heater 203 or the regulating valve 219 and the bypass pipe 217, the outer expansion valve 213 passes through the outdoor heat exchanger 102, passes through the four-way valve 112, and returns to the compressor 111 suction. During the de-ice operation and the cooling operation, the four-way valve 112 is switched, and the refrigerant flow is reversed and flows from the outdoor heat exchanger 102 toward the indoor heat exchanger 115.

  When the outside air temperature is high and there is no fear of freezing the bottom plate 101, it is meaningless to dissipate heat from the bottom plate heater 203, and the necessary heat absorption amount in the outdoor heat exchanger 102 increases, the evaporation temperature decreases, and the compressor As a result of the suction pressure of 111 being lowered and the drive rotation speed of the compressor 111 being increased in order to obtain a predetermined capacity, the electrical input may be increased. On the other hand, if there is no concern about freezing, if the bottom plate heater 203 is in an endothermic state, it can absorb heat not only from the indoor heat exchanger 102 but also from the bottom plate 101, so that the evaporation temperature and suction pressure rise and the electrical input is reduced. Can do.

  On the other hand, when there is a possibility of freezing, radiating heat from the bottom plate heater 203 is effective in preventing freezing, but at the expense of an increase in electrical input as in the case described above. Therefore, at this time, in order to minimize the increase in the electric input, the pressure of the bottom plate heater 203 is set to the saturation temperature corresponding to the outside temperature during the heating operation to reduce the heat transfer between the bottom plate 101 and the deice operation. It is preferable to radiate heat from the bottom plate heater 203 for a predetermined time before and after the interval.

  Furthermore, when performing heat dissipation or heat absorption from the bottom plate heater 203, the adjustment valve 219 is closed to increase the refrigerant flow rate of the bottom plate heater 203, and when reducing heat transfer in the bottom plate heater 203, the adjustment valve 219 is set. If it is opened and the refrigerant flow rate of the bottom plate heater 203 is reduced, the heat transfer can be controlled with high accuracy.

  Therefore, when the bottom plate 101 is not likely to freeze during the heating operation, the outer expansion valve 213 is opened, the adjustment valve 219 is closed, and the inner expansion valve 214 is adjusted to realize a predetermined heat pump cycle. If there is a risk of freezing, the adjustment valve 219 is opened, the inner expansion valve 214 is adjusted so that the temperature detected by the thermistors 216 and 218 is equivalent to the outside air temperature, and the outer expansion valve 213 is adjusted to obtain a predetermined heat pump. It is better to realize the cycle.

  During the de-ice operation, the refrigerant flow is reversed from that during heating, and the refrigerant discharged from the compressor 111 reaches the outer expansion valve 213 through the four-way valve 112 and the outdoor heat exchanger 102, but dissipates heat from the bottom plate heater 203. Therefore, the outer expansion valve 213 is opened, the adjustment valve 219 is closed, and the inner expansion valve 214 is adjusted so as to be in a predetermined cycle state. At this time, if the determination of the end of the de-ice operation is made when the detected temperature of the thermistor 218 exceeds a predetermined temperature, or when the difference between the detected temperatures of the thermistor 216 and the thermistor 218 becomes smaller than a predetermined value, the de-ice operation is reliably determined. Deice and condensed water can be drained.

  Also, during cooling operation, the same movement as during de-ice operation, if heat is radiated from the bottom plate heater 203, heat can be radiated not only from the indoor heat exchanger 102 but also from the bottom plate 101, so the condensation temperature is lowered and electric input is reduced. be able to.

  Further, particularly when the outside air temperature is low and the temperature of the bottom plate 101 is low, from the state where there is a risk of freezing before the predetermined time before entering the de-ice operation, from the bottom plate heater 203 in the heating operation. When shifting to a state of radiating heat, the bottom plate 101 can be preheated and freeze prevention is more reliable. The state of releasing heat from the bottom plate heater 203 in the heating operation means that the adjusting valve 219 that has been opened is closed, the inner expansion valve 214 is opened, and the cycle is adjusted by the outer expansion valve 213.

Explanatory drawing of the air conditioner which shows this invention and Embodiment 1 Explanatory drawing of control of the air conditioner which is this invention and one Example Explanatory drawing of the air conditioner which shows this invention and Embodiment 2 Illustration of a conventional air conditioner

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Bottom plate 102 Outdoor heat exchanger 103 Heater 113 Expansion valve 115 Indoor heat exchanger 203 Bottom plate heater 213 Outer expansion valve 214 Inner expansion valve 216, 218 Thermistor 217 Bypass pipe 219 Adjustment valve

Claims (7)

A compressor, an indoor heat exchanger, a decompression expansion means, and an outdoor heat exchanger are connected in order to form a heat pump cycle, and a heating means is provided in the lower part of the outdoor heat exchanger or the drain water drainage path, and the heating An air conditioner characterized in that the means is operated from a predetermined time before the start of the defrosting operation to a predetermined time after the end of the defrosting operation. The air conditioner according to claim 1, wherein the heating means is an electric heater. 2. The air conditioner according to claim 1, wherein during the operation of the heating unit, the power consumption of the heating unit is controlled so that the total power consumption or current value of the apparatus does not exceed a predetermined value. The air conditioner according to claim 1, wherein the heating means is means for transferring heat from a refrigerant. A first depressurizing expansion unit and a second depressurizing expansion unit, wherein the heating unit is arranged between the first depressurizing expansion unit and the second depressurizing expansion unit, and the first depressurizing expansion unit and the The second decompression / expansion means is controlled so that the refrigerant flowing through the heating means is in a high heat release state during cooling operation and during operation of the heating means, and the refrigerant flowing through the heating means is low pressure during heating operation. The air conditioner according to claim 4, wherein the air conditioner is controlled to be in an endothermic state or a state in which heat transfer is suppressed at an intermediate pressure. 6. The air according to claim 5, wherein temperature detection means are provided at an inlet and an outlet of the heating means, and the first reduced pressure expansion means and the second reduced pressure expansion means are controlled according to the output of the temperature detection means. Harmony machine. 6. The air conditioner according to claim 5, further comprising a refrigerant flow rate adjusting means for adjusting the flow rate of the refrigerant while connecting the first reduced pressure expansion means and the second reduced pressure expansion means by bypassing the heating means. Machine.

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