JP2007285571A - Heat pump equipment - Google Patents

Abstract

The present invention provides a heat pump device capable of heating a compressor in a short time and reducing energy loss and improving operating efficiency.
A compressor is driven when a temperature of the compressor becomes equal to or lower than a first reference temperature (T1). The temperature of the compressor 25 is detected as the discharge pipe temperature (Td) of the compressor 25. The driving frequency during driving is set to the lower limit operating frequency (Fmin), and when the temperature of the compressor 25 becomes equal to or higher than the second reference temperature (T2), the driving of the compressor 25 is stopped.
[Selection] Figure 4

Description

  The present invention relates to a heat pump device.

  The heat pump type hot water heater includes a hot water supply cycle 1 and a refrigerant cycle 2 as shown in FIG. 1 which is also a diagram showing an embodiment of the present invention. The hot water supply cycle 1 includes a hot water storage tank 3, and hot water stored in the hot water storage tank 3 is supplied to a bathtub or the like (not shown). That is, the hot water storage tank 3 is provided with a water supply port 5 on its bottom wall and a hot water supply port 6 on its upper wall. Then, tap water is supplied from the water supply port 5 to the hot water storage tank 3, and hot hot water is discharged from the hot water supply port 6. The hot water storage tank 3 has a water intake 10 at the bottom wall and a hot water inlet 11 at the top of the side wall (peripheral wall). The water intake 10 and the hot water inlet 11 are connected by a circulation path 12. Has been. The circulation path 12 is provided with a water circulation pump 13 and a heat exchange path 14. A water supply channel 8 is connected to the water supply port 5.

  The circulation path 12 is provided with a bypass flow path 15. That is, the bypass flow path 15 branches from the hot water inlet 11 side and is connected to the lower part (in this case, the bottom wall) of the hot water storage tank 3. A first opening / closing valve 17 is interposed between the branching portion 16 and the hot water inlet 11, and a second opening / closing valve 18 is interposed on the branching portion 16 side of the bypass flow path 15. Each on-off valve 17, 18 constitutes a bypass switching means 19. The on-off valves 17 and 18 of the bypass switching means 19 are controlled by a control means 20 described later.

  Accordingly, when the first on-off valve 17 of the bypass switching means 19 is opened and the second on-off valve 18 is closed and the water circulation pump 13 is driven, the hot water that has flowed out of the intake port 10 into the circulation path 12 is reached. Flows through the heat exchange path 14 and flows into the upper part of the hot water storage tank 3 from the heat exchange path 14 via the hot water inlet 11. Hereinafter, the state of flowing into the upper part of the hot water storage tank 3 through the hot water inlet 11 will be referred to as a normal circulation state. On the other hand, when the first on-off valve 17 of the bypass switching means 19 is closed and the second on-off valve 18 is opened and the water circulation pump 13 is driven, the water intake 10 is connected to the circulation path 12. The hot water that has flowed out flows through the heat exchange path 14, enters the bypass flow path 15 via the branch portion 16 from the heat exchange path 14, and flows into the lower portion of the hot water storage tank 3 from the bypass flow path 15. Hereinafter, such a state of flowing from the bypass flow path 15 to the lower part of the hot water storage tank 3 is referred to as a bypass circulation state. For this reason, warm water (low temperature water) does not flow into the upper part of the hot water storage tank 3 in the bypass circulation state.

  The circulation path 12 includes a pipe 21 on the hot water supply cycle 1 side and a pipe 22 of the refrigerant cycle 2, and the pipes 21 and 22 are connected by connecting pipes 23 and 24. Since the communication pipes 23 and 24 are disposed on the outdoor side, the inside may be frozen when the outside air temperature is low.

  Next, the refrigerant cycle (heat pump type heating) 2 includes a refrigerant circulation circuit, and this refrigerant circulation circuit includes a compressor 25, a water heat exchanger 26 that constitutes the heat exchange path 14, and a pressure reducing mechanism (electric expansion valve). 27 and the air heat exchanger 28 are connected in order. That is, the discharge pipe 29 of the compressor 25 is connected to the water heat exchanger 26, the water heat exchanger 26 and the electric expansion valve 27 are connected by the refrigerant passage 30, and the electric expansion valve 27 and the air heat exchanger 28 are connected. Are connected by a refrigerant passage 31, and the air heat exchanger 28 and the compressor 25 are connected by a refrigerant passage 33 in which an accumulator 32 is interposed. Moreover, as a refrigerant | coolant, the supercritical refrigerant | coolant (for example, carbon dioxide gas) used supercritically for a refrigerant | coolant is used. The air heat exchanger 28 is provided with a fan 34 that adjusts the capacity of the air heat exchanger 28.

  The circulation path 12 includes an incoming thermistor 35 a that detects the temperature (incoming water temperature) of hot water (low temperature water) that flows out from the water intake 10 and enters the heat exchange path 14, and hot water heated in the heat exchange path 14. And a hot water thermistor 36a for detecting the temperature (hot water temperature) of the hot water. Further, the air heat exchanger 28 is provided with an air heat exchange thermistor 48 a that detects the temperature of the air heat exchanger 28. In FIG. 1, reference numeral 37a denotes an outside air temperature detection thermistor for detecting the outside air temperature, and reference numeral 40a denotes a discharge pipe temperature detection thermistor.

  Further, the discharge pipe 29 and the refrigerant passage 31 (the position immediately before the air heat exchanger 28 in the passage connecting the electric expansion valve 27 and the air heat exchanger 28) are connected by a defrost circuit 38 having a defrost valve 39. Has been. That is, the hot gas from the compressor 25 can be directly supplied to the air heat exchanger 28 functioning as an evaporator, thereby enabling a defrost operation for removing the frost of the evaporator 28. Therefore, this refrigerant cycle 2 can perform a normal hot water heating operation and a defrost operation.

  Further, the refrigerant circulation circuit is provided with a bypass circuit 42 that branches on the high-pressure side and merges at a position downstream of the branch portion, and a refrigerant regulator 43 is provided in the bypass circuit 42. An adjustment valve 44 for adjusting the flow rate is provided on the outlet side of the refrigerant regulator 43. That is, the bypass circuit 42 branches from the upstream side of the water heat exchanger 26 and is connected to the refrigerant regulator 43, and is led out from the refrigerant regulator 43 and is branched from the branch portion of the first passage 45. And a second passage 46 that merges with the water heat exchanger 26 on the downstream side. The flow rate adjusting valve 44 is interposed in the second passage 46.

  A passage 47 that constitutes a part of the refrigerant passage 31 is disposed in the refrigerant regulator 43, and the high-pressure refrigerant that has entered the refrigerant regulator 43 via the bypass circuit 42 and the passage 47 Heat exchange with low-pressure refrigerant flowing through In this case, the refrigerant flow rate in the refrigerant regulator 43 is adjusted by adjusting the opening degree of the adjustment valve 44 to adjust the refrigerant temperature in the refrigerant regulator 43. This is because the required refrigerant temperature can be maintained by controlling the opening degree of the flow rate adjusting valve 44, and the refrigerant regulator 43 can be set to an appropriate refrigerant capacity, and the refrigerant circulation amount in this circuit can be set to an optimum amount. This is because.

  By the way, as shown in FIG. 2, the control unit of the heat pump type hot water heater includes an incoming water temperature detection means 35, a hot water temperature detection means 36, an outside air temperature detection means 37, a discharge pipe temperature detection means 40, and air heat. An exchanger temperature detecting means 48, a timer means 50, a control means 20 and the like are provided. Data from these detection means 35, 36, 37, 48, timer means 50 and the like is input to the control means 20, and the control means 20 uses the compressor 25 and the defrost valve 39 based on these data and the like. A control signal is transmitted to the compressor 25, and the compressor 25 and the like are operated based on the control signal. The incoming water temperature detecting means 35 can be constituted by the incoming water thermistor 35a, the hot water temperature detecting means 36 can be constituted by the outgoing hot water thermistor 36a, and the outside air temperature detecting means 37 can be constituted by the outside air temperature detecting thermistor 37a. The discharge pipe temperature detection means 40 can be constituted by a discharge pipe temperature detection thermistor 40a, and the air heat exchanger temperature detection means 48 can be constituted by the air heat exchange thermistor 48a. Furthermore, the timer means 50 can be configured by an existing timer or the like that measures time. The control means 20 can be constituted by a microcomputer, for example.

  According to the heat pump type water heater configured as described above, the bypass switching means 19 is set in the normal circulation state, the defrost valve 39 is closed, the compressor 25 is driven, and the water circulation pump 13 is driven ( When activated), the stored water (low temperature water) flows out from the water intake 10 provided at the bottom of the hot water storage tank 3, and this flows through the heat exchange path 14 of the circulation path 12. At this time, the hot water is heated (boiling) by the water heat exchanger 26 and returned (inflow) from the hot water inlet 11 to the upper portion of the hot water storage tank 3. By continuously performing such an operation, hot hot water can be stored in the hot water storage tank 3. In addition, this kind of heat pump apparatus is well-known as it is disclosed by patent document 1, for example.

By the way, in the heat pump apparatus as described above, when the compressor 25 is continuously stopped and its temperature is lowered in winter or the like, it is possible to prevent the stagnation of the refrigerant and to ensure the startability. When the carbon dioxide refrigerant is used, it is necessary to heat the compressor 25 in order to ensure electrical insulation and durability. For this reason, as is well known, measures have been taken to cause phase loss energization of the motor of the compressor 25 (for example, Patent Document 2 and Patent Document 3).
JP 2003-222391 A Japanese Patent Laid-Open No. 08-110102 JP 2002-266762 A

  However, in the case of adopting the method of performing phase loss energization to heat the heat pump device as described above, it takes a long time to heat the compressor, and the electric power consumed for the heating is the heat pump Since it does not contribute to the function at all, it is a wasteful electric power.

  The present invention has been made to solve the above-mentioned conventional drawbacks, and its purpose is to be able to heat the compressor in a short time, and to reduce the energy loss and improve the operation efficiency. An object of the present invention is to provide a heat pump device capable of performing the above.

  Therefore, the heat pump device of the present invention is characterized in that in the heat pump device having the hermetic compressor 25, the compressor 25 is driven when the temperature of the compressor becomes equal to or lower than the first reference temperature (T1).

  The heat pump device according to the present invention is characterized in that the temperature of the compressor 25 is detected as a discharge pipe temperature (Td) of the compressor 25.

  Furthermore, the heat pump device of the present invention is characterized in that the compressor 25 has a variable compression capability, and the drive frequency at the time of the drive is the lower limit operation frequency (Fmin).

  The heat pump device of the present invention is characterized in that after the compressor 25 is operated for a predetermined time, the compressor 25 is stopped.

  The heat pump device of the present invention stops the driving of the compressor 25 when the temperature of the compressor 25 becomes equal to or higher than the second reference temperature (T2) higher than the first reference temperature (T1). Features.

  In the heat pump device of the present invention, the compressor 25 is subjected to open loop control immediately after startup, and then closed loop control is started when the temperature of the compressor 25 rises to a predetermined temperature. The second reference temperature (T2) is set lower than the predetermined temperature.

  In the heat pump device, since the compressor 25 is driven to heat the compressor 25, the driving electric power contributes to the heat pump function, so that energy loss can be reduced and operating efficiency can be improved. It becomes possible. In addition, it is possible to heat the compressor 25 in a shorter time than when performing phase loss energization. Further, if the lower limit frequency (Fmin) is used as the operating frequency at that time, use of electric power unnecessary for heating the compressor 25 can be suppressed, and energy efficiency can be improved. Furthermore, when the temperature of the compressor 25 is replaced with the discharge pipe temperature (Td), or the driving of the compressor 25 is stopped in a predetermined time, the control configuration can be simplified. Further, if the driving of the compressor 25 is stopped when the temperature of the compressor 25 becomes equal to or higher than the second reference temperature (T2), the energy efficiency can be further improved and the closed loop control is not performed. In this case, the control configuration can be simplified.

  Next, specific embodiments of the heat pump device of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a simplified circuit diagram of a heat pump device (heat pump type water heater) in the embodiment, and FIG. 2 shows a simplified block diagram of its control unit, which have been described in relation to the conventional example. The description is omitted because it is the same as the above. The compressor 25 in this heat pump type hot water heater is an inverter compressor having a variable compression capability, and includes a compression element and an electric element that drives the compression element in a hermetic container, like the known compressor 25 ( Not shown). The compressor 25 is subjected to start-up control as shown in FIG. First, when a starting operation is performed, the operating frequency of the compressor 25 is raised to the lower limit circumferential operating wave number (Fmin). This lower limit operating frequency (Fmin) is appropriately determined in consideration of torque necessary for the compression element when the operation of the compressor 25 is continued, and is normally set to about 40 Hz, for example. . Then, after being held for a certain time in this state, it is raised stepwise and finally raised to the target operating frequency (Fsr). The target operating frequency (Fsr) is determined by the control means 20 according to the outside air temperature, the incoming water temperature, the target hot water temperature, and the like.

  In the heat pump device, when the compressor 25 is started, open loop control is performed from immediately after the compressor 25 is started until the discharge pipe temperature (Td) reaches a predetermined temperature (for example, 60 ° C.). When the discharge pipe temperature (Td) of the compressor 25 rises to the predetermined temperature, the closed loop control is started.

  FIG. 4 shows a flowchart of the heating operation control method when the compressor 25 is stopped. First, in step S1, the heating operation is started when the discharge pipe temperature (Td) becomes equal to or lower than the first reference temperature (for example, 10 ° C.) (T1). At this time, the operating frequency of the compressor 25 is set to the lower limit operating frequency (Fmin) (step S2). Moreover, in the said water heater, while switching the bypass switching means 19 to a bypass circulation state, the water circulation pump 13 is driven. That is, when the first on-off valve 17 of the bypass switching means 19 is closed and the second on-off valve 18 is opened and the water circulation pump 13 is driven, the hot water flowing out from the water intake 10 to the circulation path 12 is Since the heat exchange path 14 flows into the bypass flow path 15 from the heat exchange path 14 via the branching portion 16 and flows into the lower part of the hot water storage tank 3 from the bypass flow path 15, such a bypass circulation state It is set as. In step S3, the operation of the compressor 25 is stopped when the discharge pipe temperature (Td) becomes equal to or higher than the second reference temperature (for example, 40 ° C.) (T2). In this case, in the heat pump device, since the discharge pipe temperature (Td) is kept below the start temperature of the closed loop control, the compressor 25 is not closed loop controlled, and the opening degree of the electric expansion valve 27 is initially set. The set opening is maintained.

  In the heat pump device, since the compressor 25 is driven to heat the compressor 25, the driving power is consumed to heat the hot water inside the hot water storage tank 3. As a result, the energy loss can be reduced and the driving efficiency can be improved. In addition, it is possible to heat the compressor 25 in a short time as compared with the case where the phase loss energization is performed, and the start-up performance can be improved. Moreover, since the operation of the compressor 25 is often performed regardless of the user's intention, the heat pump water heater has little discomfort on the user even if the compressor 25 is suddenly operated. Impairing comfort is suppressed. Further, since the lower limit frequency (Fmin) is used as the operating frequency at that time, use of electric power unnecessary for heating the compressor 25 can be suppressed, and energy efficiency can be improved. Furthermore, since the temperature of the compressor 25 is replaced by the discharge pipe temperature (Td), the control configuration can be simplified. Further, if the drive of the compressor 25 is stopped when the temperature of the compressor 25 becomes equal to or higher than the second reference temperature (T2), energy efficiency can be further improved. Further, when the closed loop control is not performed as described above, the control configuration can be simplified. Further, as described above, the bypass passage 15 that bypasses the interior of the hot water storage tank 3 and communicates the upper hot water inlet 11 and the lower water intake 10 is provided in parallel with the water heat exchanger 14. When the hot water heated by the water heat exchanger 15 is allowed to flow into the bypass flow path 15 during the operation, the driving power of the compressor 25 is connected to the connecting pipe 23, 24 can contribute to prevention of freezing, and energy efficiency can be further improved.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, in the above, when the temperature of the compressor 25 becomes equal to or higher than the second reference temperature (T2), the operation of the compressor 25 is stopped, but after the drive of the compressor 25 is started as described above. After a predetermined time has elapsed, the operation may be uniquely stopped regardless of the temperature of the compressor 25. In this case, there is an advantage that the control configuration can be simplified. Moreover, as a heat pump apparatus, it is applicable not only to a hot water supply machine but to various apparatuses, such as an air conditioner. Carbon dioxide gas is preferably used as the refrigerant of this heat pump device, but other refrigerants such as dichlorodifluoromethane (R-12) and chlorodifluoromethane (R-22) can also be used in the ozone layer. An alternative refrigerant such as 1,1,1,2-tetrafluoroethane (R-134a) may be used because of problems such as destruction and environmental pollution.

It is a simplified circuit diagram of the heat pump type hot water heater as an embodiment of the present invention. It is a simplified block diagram of the control part of the said heat pump type water heater. It is a time chart which shows the frequency control at the time of starting of the said heat pump type water heater. It is a flowchart figure of the heating method of the said heat pump type water heater.

Explanation of symbols

25 Compressor T1 First reference temperature T2 Second reference temperature Td Discharge piping temperature

Claims (6)

  A heat pump apparatus having a hermetic compressor (25), wherein the compressor (25) is driven when the temperature of the compressor (25) becomes equal to or lower than a first reference temperature (T1).   The heat pump device according to claim 1, wherein the temperature of the compressor (25) is detected as a discharge pipe temperature (Td) of the compressor (25).   The heat pump device according to claim 1 or 2, wherein the compressor (25) has a variable compression capacity, and the driving frequency during the driving is a lower limit operating frequency (Fmin).   The heat pump device according to any one of claims 1 to 3, wherein the compressor (25) is stopped after the compressor (25) has been operated for a predetermined time.   When the temperature of the compressor (25) becomes equal to or higher than the second reference temperature (T2) higher than the first reference temperature (T1), the driving of the compressor (25) is stopped. The heat pump apparatus in any one of Claims 1-3.   The compressor (25) is subjected to open loop control immediately after startup, and then closed loop control is started when the temperature of the compressor (25) rises to a predetermined temperature. 6. The heat pump device according to claim 5, wherein the temperature (T2) is set lower than the predetermined temperature.