JP2012032091A - Heat pump cycle system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump cycle system capable of efficiently carrying out a heating cycle operation at a low outside air temperature while improving the durability of a compressor by preventing the intake pressure of the compressor from becoming lower than a lower limit.SOLUTION: When detected condensation pressure or a water temperature and an outside air temperature are lower than predetermined values, an allowable maximum rotational frequency of the compressor 1 is set low compared with the case that these are equal to predetermined values or higher. When the condensation pressure or the water temperature, and the outside air temperature are low and when the intake pressure of the compressor 1 is low, the durability of the compressor 1 is improved by controlling the intake pressure of the compressor 1 so as not to become lower than the lower limit by decreasing a refrigerant circulation amount in an outdoor heat exchanger 5 by lowering the allowable maximum rotational frequency of the compressor 1. When the condensation pressure or the water temperature, and the outside air temperature are equal to the predetermined values or higher, the heating cycle operation can be efficiently carried out by improving an operation capacity of the compressor 1 by setting the allowable maximum rotational frequency of the compressor 1 high.

Description

  The present invention relates to a heat pump cycle device such as a heat pump type hot / cold water air conditioner or a heat pump type hot water supply device, and more specifically, to perform a more efficient operation while protecting a compressor at a low outside temperature. The present invention relates to a heat pump cycle device that can be used.

  Conventionally, a heat pump cycle apparatus has a refrigerant circuit in which a compressor, a four-way valve, a use-side heat exchanger, an electronic expansion valve, and an outdoor heat exchanger that is a heat source-side heat exchanger are sequentially connected by piping. is doing. When performing heating operation or hot water supply operation with this heat pump cycle device, the refrigerant circuit becomes a heating cycle, and the refrigerant compressed into high-temperature and high-pressure gas by the compressor passes through the four-way valve and heats it with the use side heat exchanger. It is discharged to become liquid refrigerant, further reduced in pressure by the electronic expansion valve, evaporated in the outdoor heat exchanger, exchanged with outdoor air, and converted into gas and compressed again by the compressor. In the cooling / defrosting operation, the refrigerant circuit is in a cooling cycle in which the four-way valve is switched to flow in the direction opposite to the refrigerant flow described above.

  In such a heat pump cycle device, the operating capability of the heat pump cycle device at the same compressor speed changes when the outside air temperature is low and high. Therefore, a heat pump cycle device has been proposed that detects the outside air temperature and controls the operating capacity by controlling the rotation speed of the compressor and the opening of the expansion valve in accordance with the detected change in the outside air temperature. (For example, see Patent Document 1).

  Patent Document 1 discloses a refrigeration cycle apparatus having a refrigerant circuit to which a compressor, a use side heat exchanger, an electronic expansion valve, and an outdoor heat exchanger that is a heat source side heat exchanger are connected, and the refrigeration cycle. A hot water storage tank for storing hot water heated by the device, and the outside air temperature are detected at regular intervals, and the compression function force (number of rotations) and the electronic expansion valve are opened according to a predetermined standard with respect to the detected change in the outside air temperature. A heat pump type hot water supply device provided with a control device for controlling the degree is described.

  In this heat pump type hot water supply device, the control device detects the outside air temperature every predetermined time, for example, every 30 minutes, and detects the change in the outside air temperature. Then, the control device, in accordance with the detected change in the outside air temperature, a predetermined reference, for example, a table in which the outside air temperature measured in advance in a test or the like and stored in the control device is associated with the rotation speed of the compressor, etc. Accordingly, by controlling the rotation speed of the compressor and the opening of the electric expansion valve, the operation capability of the heat pump hot water supply device can be controlled to operate efficiently.

  When the heat pump cycle apparatus as described above is operated in a heating cycle, when trying to obtain the same water temperature (the hot water temperature obtained by the water use side heat exchanger), the lower the outside air temperature, the lower the water temperature. Since control is performed to increase the operating capacity so as not to decrease, the evaporation pressure in the outdoor heat exchanger decreases and the suction pressure of the compressor decreases.

  Therefore, in the low outside air temperature region (for example, when the outside air temperature is −15 ° C. or lower), the suction pressure of the compressor is a lower limit value of the suction pressure individually determined for the compressor (for example, 0.16 megapascal). If the suction pressure of the compressor falls below the lower limit, phenomena such as breakage of the vane valve of the compressor and generation of abnormal noise may occur, and the reliability of the compressor may not be ensured.

  Therefore, as a solution to the above-described problem, when the outside air temperature is low, the allowable maximum number of rotations of the compressor is set low, the refrigerant circulation amount in the outdoor heat exchanger is reduced, and the temperature of the outdoor heat exchanger does not decrease. By doing so, a method is conceivable in which a decrease in the evaporation pressure and thus a decrease in the suction pressure is suppressed, so that the suction pressure of the compressor does not fall below a lower limit value.

  When the outside air temperature is constant, the evaporation pressure in the outdoor heat exchanger increases and the suction pressure increases as the water temperature increases. That is, even if the outside air temperature is low, if the water temperature is high, it is considered that the compressor suction pressure has a margin with respect to the lower limit value, so the allowable maximum rotational speed of the compressor is increased (for example, It can be considered that there is no problem even if it is set as the upper limit value of the rotational speed individually determined for the compressor. Therefore, in the method of determining the maximum allowable rotation speed of the compressor only with the outside air temperature in the low outside air temperature region, the allowable pressure of the compressor is high even though the water temperature is high and the intake pressure of the compressor has a margin with respect to the lower limit value. There was a case where the maximum number of revolutions was set low, and there was a possibility that efficient heating cycle operation could not be performed.

Japanese Unexamined Patent Publication No. 2003-74970 (pages 3 to 5, FIGS. 2 and 3)

  The present invention solves the above-described problems, and improves the durability of the compressor so that the suction pressure of the compressor does not fall below the lower limit value, and enables a more efficient heating cycle operation at a low outside air temperature. An object is to provide an apparatus.

  The present invention solves the above-mentioned problem, and the heat pump cycle device of the present invention includes a refrigerant circuit having a compressor, a use side heat exchanger, an expansion valve, and a heat source side heat exchanger, and a condensation pressure detecting means. And / or a water temperature detection means, an outside air temperature detection means, and a control means, wherein the control means detects the condensation pressure by the condensation pressure detection means or detects the water temperature by the water temperature detection means. When the outside air temperature is detected by the outside air temperature detecting means, and the detected condensing pressure or water temperature and the outside air temperature are respectively lower than predetermined values, the condensing pressure or water temperature and the outside air temperature are respectively predetermined values. Compared to the case described above, the allowable maximum rotational speed of the compressor is set low.

  Further, the control means has a compressor rotation speed table that stores a maximum allowable rotation speed of the compressor in correspondence with a plurality of condensing pressures or a plurality of water temperatures in the refrigerant circuit and an outside air temperature.

  In the heat pump cycle device of the present invention, when the detected condensing pressure or water temperature and the outside air temperature are each lower than a predetermined value, the condensing pressure or water temperature and the outside air temperature are respectively higher than or equal to a predetermined value. Therefore, the allowable maximum number of rotations of the compressor is set low. Therefore, when the condensing pressure or water temperature and the outside air temperature are low and the compressor suction pressure is low, the allowable maximum rotation speed of the compressor is lowered to control the compressor suction pressure so that it does not decrease. In addition to improving durability, when the condensing pressure or water temperature and the outside air temperature are above the specified values, compression is performed by increasing the maximum allowable rotational speed of the compressor and increasing the discharge pressure of the compressor. Efficient heating cycle operation can be performed by improving the operation capacity of the machine.

It is a block diagram of the heat pump cycle apparatus in the Example of this invention. It is a compressor rotation speed table in the Example of this invention. It is a flowchart explaining the control by the Example of this invention. It is a compressor rotation speed table in the other Example of this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. As an example, a heat pump cycle device having an indoor unit such as a floor heating device or an indoor unit and performing heat exchange between water and refrigerant in a use side heat exchanger will be described as an example. The present invention is not limited to the following embodiments, and can be variously modified without departing from the gist of the present invention.

  FIG. 1 shows a configuration of a heat pump cycle apparatus according to the present invention. The heat pump cycle device 100 includes a compressor 1, a four-way valve 2, a use side heat exchanger 3 that performs heat exchange between refrigerant and water, a first expansion valve 4, an outdoor heat exchanger 5 that is a heat source side heat exchanger, The accumulator 6 is connected by the refrigerant | coolant piping 12 in order, and the refrigerant circuit is comprised, and it is comprised so that the refrigerant | coolant circulation direction may be switched via the four-way valve 2. FIG. Further, between the use side heat exchanger 3 of the refrigerant pipe 12 and the first expansion valve 4 and a refrigerant inlet (not shown) of the compressor 1, an injection having a second expansion valve 15 and an electromagnetic opening / closing valve 16. They are connected by a pipe 14.

  The use side heat exchanger 3 has a use side heat exchange temperature sensor 20 that detects the temperature of the refrigerant flowing through the refrigerant pipe 12, and an outdoor temperature sensor 21 that is an outside air temperature detection means in the vicinity of the outdoor heat exchanger 5. A discharge temperature sensor 22 for detecting a refrigerant discharge temperature is detected near the discharge port of the compressor 1, and a refrigerant temperature near the first expansion valve is detected between the use side heat exchanger 3 and the first expansion valve 4. Between the first expansion valve 4 and the outdoor heat exchanger 5, an outdoor heat exchanger temperature sensor 25 for detecting the temperature of the outdoor heat exchanger 5 is installed. Furthermore, a pressure sensor 30 serving as a condensation pressure detecting means is disposed on the refrigerant 1 discharge side of the refrigerant pipe 12 (between the four-way valve 2 and the use-side heat exchanger 3).

  A refrigerant pipe 12 and a water pipe 13 are connected to the use side heat exchanger 3, and a circulation pump 17 for circulating water through the indoor unit 11 is connected to the water pipe 13. The flow of heat-exchanged water is configured to circulate in the direction of the arrow 62 shown in FIG. Further, an inlet-side water temperature sensor 24, which is a water temperature detecting means, is provided near the water inlet of the use-side heat exchanger 3, and an outlet-side water temperature sensor 26, which is a water temperature detecting means, is provided near the water outlet of the use-side heat exchanger 3. Are installed.

  The heat pump cycle apparatus 100 inputs the temperature detected by each temperature sensor and the condensing pressure detected by the pressure sensor 30, or the compressor 1 and the four-way valve 2 in response to an operation request from a user using a remote controller (not shown). And a control means 10 for controlling the heat pump cycle device 100 by controlling the driving of the circulation pump 17, the electromagnetic on-off valve 16, the first expansion valve 4 and the second expansion valve 15. The control means 10 controls the output frequency of the inverter (not shown) to control the rotational speed of the compressor 1, and the rotational speed of the compressor 1 is periodically stored as management data in a storage unit of the control means 10 (not shown). Yes.

  In FIG. 1, the refrigerant flow direction during heating operation, that is, during the heating cycle is indicated by an arrow 60, and the second expansion valve 15 and the electromagnetic opening / closing valve 16 are opened and the refrigerant flows into the injection pipe 14. The refrigerant flow directions are indicated by arrows 61, respectively. In addition, the refrigerant flow direction during cooling operation or defrosting operation, that is, during operation in the cooling cycle is opposite to the refrigerant flow direction during heating operation (the direction of arrow 60). Is omitted.

  The operation of the heat pump cycle apparatus 100 having the above-described configuration will be described by taking a case where the heating operation is performed as an example. When the user operates the remote control or the like of the indoor unit 11 to turn on the switch, the heat pump cycle device 100 starts operation, and the control means 10 rotates the circulation pump 17 to connect the use side heat exchanger 3 and the indoor unit 11. Circulate water between them.

  At the same time, the controller 10 sets the current water temperature detected by the outlet-side water temperature sensor 26, that is, the temperature of the water heated by the use-side heat exchanger 3, as a target temperature for heating operation determined by the user. The compressor 1 is rotated so that the temperature of water corresponds to. The refrigerant that has become a high-temperature and high-pressure gas in the compressor 1 passes through the four-way valve 2, becomes a liquid by exchanging heat with water in the use-side heat exchanger 3, and further depressurized in the first expansion valve 4, so that it is an outdoor heat exchanger. In step 5, heat is exchanged with outdoor air to evaporate, and the process of being converted into gas and compressed by the compressor 1 is repeated. The four-way valve 2 is used to reverse the direction of refrigerant circulation during cooling and defrosting operations.

  In addition, when the outside air temperature is low and a high water temperature is required during heating operation, the control means 10 opens the electromagnetic on-off valve 16 and adjusts the condensing pressure detected by the pressure sensor 30 and the rotation speed of the compressor 1. 2 Open the expansion valve 15 at a predetermined opening to turn on the injection. When the injection is turned on, liquid refrigerant is injected into the mechanical portion of the compressor 1 to lower the discharge temperature of the compressor 1 and increase the amount of refrigerant circulating in the use-side heat exchanger 3, so that the outside air temperature is high at a low temperature. Even when the water temperature is required, high heating capacity can be exhibited by increasing the refrigerant flow rate in the use side heat exchanger 3. During the cooling operation or the defrosting operation, the electromagnetic on-off valve 16 is kept closed, that is, the injection is OFF.

  Next, using FIG. 1 to FIG. 3, when the heating operation is performed at the low outside air temperature in this embodiment, the allowable maximum rotation speed of the compressor 1 is determined so that the suction pressure of the compressor 1 does not fall below the lower limit value. The principle and control will be described. In the compressor 1 of the present embodiment, the description will be made on the assumption that the upper limit value of the rotational speed individually determined for the compressor is 90 rps. A compressor speed table A shown in FIG. 2 is stored in the storage unit of the control means 10. In the compressor rotation speed table A, the allowable maximum rotation speed (unit: rps) of the compressor 1 is determined in correspondence with the condensation pressure and the outside air temperature during the heating operation in the low outside air temperature region. The item is the outside air temperature (unit: ° C). The low outside air temperature region means a temperature region where it is necessary to control the maximum allowable number of rotations of the compressor 1 in this embodiment. In this embodiment, the outside air temperature is a temperature of −15 ° C. or lower. The region is a low outside air temperature region. In addition, the outside air temperature range of −15 ° C. or lower is divided every 5 ° C. into the outside air temperature range.

  The allowable maximum rotation speed of the compressor 1 is “condensation pressure: less than 2.1 MPa (megapascal, hereinafter referred to as MPa)” and “condensation pressure: 2.1 MPa or more” for each outside air temperature range. When the condensation pressure is less than 2.1 MPa, the allowable maximum number of revolutions of the compressor 1 in each outside air temperature range is 80 rps when the outside air temperature is less than −20 ° C., and the outside air temperature is − When the temperature is 20 ° C. or higher and lower than −15 ° C. and −15 ° C. or higher, the upper limit rotation speed of the compressor 1 is 90 rps. When the condensing pressure is 2.1 MPa or higher, the allowable maximum rotational speed of the compressor 1 is 90 rps which is the upper limit rotational speed of the compressor 1 regardless of the outside air temperature range.

  When the heat pump cycle apparatus 100 is performing the heating operation, the lower the outside air temperature is, the lower the evaporation pressure in the outdoor heat exchanger 5 is, so that the suction pressure of the compressor 1 is lowered. In particular, the outside air temperature is −20. When it becomes less than ° C., the suction pressure of the compressor 1 approaches the lower limit value. On the other hand, also when the condensation pressure in the use side heat exchanger 3 is 2.1 MPa or less, the evaporation pressure in the outdoor heat exchanger 5 becomes low and the suction pressure of the compressor 1 becomes low.

  In consideration of the above, in the compressor rotation speed table A of FIG. 2, when the outside air temperature is −20 ° C. or less and the condensation pressure is less than 2.1 MPa (for example, the target water temperature is low, that is, For example, when the set temperature during heating operation is relatively low and the condensing pressure is low, the allowable maximum rotational speed of the compressor 1 is limited to 80 rps, which is lower than 90 rps, which is the upper limit rotational speed of the compressor 1. This is to reduce the refrigerant circulation amount in the outdoor heat exchanger 5 by lowering the maximum number of rotations of the compressor 1, thereby suppressing a decrease in the evaporation pressure so that the suction pressure of the compressor 1 does not fall below the lower limit value. It is to make it.

  Further, in the compressor rotation speed table A of FIG. 2, when the condensation pressure is less than 2.1 MPa and the outside air temperature is −20 ° C. or more, or when the condensation pressure is 2.1 MPa or more, the compressor 1 Is set to 90 rps, which is the upper limit number of rotations of the compressor 1. Under such conditions, the suction pressure of the compressor 1 is considered to be higher than the case where the outside air temperature is −20 ° C. or lower and the condensation pressure is less than 2.1 MPa. In order to increase the operating capacity of the compressor 1 and allow efficient heating operation at low outside air temperature by permitting an increase to the upper limit rotation speed of 90 rps without limiting the maximum allowable rotation speed. It is. In addition, the value of each allowable maximum number of rotations associated with the condensing pressure and the outside air temperature range defined in the compressor rotation number table A is obtained in advance by a test or the like.

  The operation of the heat pump cycle apparatus 100 storing the compressor rotation speed table A described above is as follows. When the user operates the remote controller or the like or starts the heating operation of the heat pump cycle apparatus 100 by starting the timer operation, the control means 10 detects the current condensing pressure detected by the pressure sensor 30 and the outside air temperature sensor 21. Extract the current outside air temperature detected by. The control means 10 refers to the compressor rotation speed table A in FIG. 2 and determines the allowable maximum rotation speed of the compressor 1 corresponding to the extracted condensing pressure and outside air temperature. And the control means 10 controls the rotation speed of the compressor 1 within the allowable maximum rotation speed in accordance with the operation load of the indoor unit 11 and the like.

  Next, the flow of processing in the control means 10 will be described using a control flowchart of the heat pump cycle apparatus 100 shown in FIG. FIG. 3A shows a main routine of the heat pump cycle apparatus 100. FIG. 3B is a routine for determining the maximum allowable number of rotations of the compressor 1 during the heating operation according to the present invention. The allowable maximum rotational speed determination routine of the compressor 1 determines the maximum rotational speed allowed by the compressor 1 during heating operation. In the main routine, the rotation speed of the compressor 1 is controlled in accordance with the operation load of the indoor unit 11 within the maximum rotation speed determined in the allowable maximum rotation speed determination routine of the compressor 1 during the heating operation.

  In the flowchart of FIG. 3, ST represents a step, and the number following this represents a step number. In FIG. 3, the processing according to the present invention is mainly described, and descriptions of general processing such as user setting operation processing and detailed water temperature control are omitted.

  As shown in FIG. 3 (A), when the heat pump cycle device 100 starts operation, the control means 10 starts rotating the circulation pump 17 and supplies water between the use side heat exchanger 3 and the indoor unit 11. Circulate (ST1). And the control means 10 takes in the water temperature of the circulating water which the exit side water temperature sensor 26 detected (ST2).

  Next, the control means 10 determines whether or not the operation mode of the heat pump cycle device 100 is set to the heating operation (ST3). When the operation mode is the heating operation (ST3-Yes), the control means 10 executes an allowable maximum rotational speed determination routine of the compressor 1 shown in FIG. 3B (ST4). And the control means 10 sets the rotation speed of the compressor 1 so that the detected value of the outlet side water temperature sensor 26 becomes the target water temperature within the allowable maximum rotation speed determined by the allowable maximum rotation speed determination routine of the compressor 1. Then, the operation of the compressor 1 is controlled to start or continue the heating operation (ST5). Then, the process is returned to ST2.

  In ST3, when the operation mode is not the heating operation, that is, in the cooling operation (ST3-No), the control means 10 compresses the detected value of the outlet side water temperature sensor 26 so as to become the target water temperature. The number of rotations of the machine 1 is determined, the operation of the compressor 1 is controlled, and the cooling operation is started or continued (ST6). Then, the process is returned to ST2.

  Next, the routine for determining the maximum allowable rotation speed of the compressor 1 shown in FIG. When the operation mode of heat pump cycle apparatus 100 is set to heating operation, control means 10 extracts the current condensing pressure and the current outside air temperature (ST11). Specifically, the control means 10 periodically takes in the condensation pressure detected by the pressure sensor 30 and the outside air temperature detected by the outside air temperature sensor 21 and stores them as management data in a storage unit of the control means 10 (not shown). The latest condensation pressure value and outside air temperature are extracted from this management data and recognized as the current condensation pressure and outside air temperature.

  In addition to the condensing pressure and the outside air temperature, the control means 10 determines the rotation speed of the compressor 1, the water temperature detected by the inlet side water temperature sensor 24 and the outlet side water temperature sensor 26, the discharge temperature detected by the discharge temperature sensor 22, and the outdoor heat. Various parameter values necessary for controlling the refrigeration cycle of the heat pump cycle device 100, such as the temperature of the outdoor heat exchanger 5 detected by the AC temperature sensor 25, and setting information such as the operation mode and temperature set by the user , Stored as management data in the storage unit.

  Next, the control means 10 refers to the compressor rotational speed table A stored in the storage unit and determines the allowable maximum rotational speed of the compressor 1 (ST12). Specifically, the allowable maximum rotational speed of the compressor 1 corresponding to the current condensing pressure and the current outside air temperature extracted in ST11 is extracted with reference to the compressor rotational speed table A shown in FIG. The maximum allowable number of rotations of the compressor 1 is determined. And the control means 10 complete | finishes a process.

  As described above, when the heat pump cycle device 100 is performing the heating operation, the allowable maximum number of rotations of the compressor 1 is set according to the condensation pressure and the outside air temperature, and further, less than the predetermined condensation pressure and the outside air temperature. (In the case of the present embodiment, the condensation pressure is less than 2.1 MPa and the outside air temperature is less than −20 ° C.), the condensation pressure is not less than the predetermined condensation pressure and not less than the outside temperature (in this embodiment, the condensation pressure is 2. Since the allowable maximum number of revolutions of the compressor 1 is set lower than when the outside air temperature is less than 1 MPa and the outside air temperature is −20 ° C. or higher, or the condensing pressure is 2.1 MPa or higher), the compressor is at a low outside air temperature. Thus, the suction pressure of the compressor 1 can be reduced so as not to fall below the lower limit value, and the durability of the compressor 1 can be improved.

  Further, when both the condensation pressure and the outside air temperature are equal to or higher than a predetermined value, the compressor 1 is allowed to rise up to the upper limit number of revolutions of 90 rps without limiting the allowable maximum number of revolutions of the compressor 1. Efficient heating operation can be performed by maximizing the operation capability and achieving the target temperature that is the target temperature even in the low outside air temperature region.

  In the embodiment described above, in the compressor rotation speed table A in FIG. 2, the allowable maximum rotation speed of the compressor 1 is defined in two cases where the condensation pressure is less than 2.1 MPa / more. However, the condensation pressure is less than 2.1 MPa / 2.1 MPa or more and less than 4.2 MPa / 4.2 MPa or more (4.2 MPa is individually determined for the compressor 1, for example. The allowable maximum number of rotations of the compressor 1 may be defined in three cases: the condensation pressure corresponding to the upper limit value of the discharge pressure.

  Further, in the compressor rotation speed table A of FIG. 2, the outside temperature range is set every 5 ° C. However, for example, even if the range width is changed such that the outside temperature range is set every 4 ° C. Good. Further, in the compressor rotation speed table A of FIG. 2, the allowable maximum rotation speed of the compressor 1 is all 90 rps except when the condensation pressure is less than 2.1 MPa and the outside air temperature is less than −20 ° C. The allowable maximum number of revolutions of the compressor 1 when the outside air temperature is −20 ° C. or more and less than −15 ° C. is 90 rps, and the allowable maximum number of revolutions of the compressor 1 when the outside temperature is −15 ° C. or more is 85 rps. In this way, the allowable maximum number of rotations of the compressor 1 that is different in a plurality of outside air temperature ranges may be set.

  Furthermore, in the compressor rotation speed table A of FIG. 2, the allowable maximum rotation speed of the compressor 1 is uniformly set for a temperature range where the outside air temperature is −15 ° C. or higher or a temperature range lower than −20 ° C. However, for a temperature range where the outside air temperature is −15 ° C. or higher and a temperature range below −20 ° C., for example, a plurality of outside air temperature ranges are set every 5 ° C., and the allowable maximum rotation speed of the compressor 1 is set for each. It may be set.

  Next, a second embodiment of the heat pump cycle apparatus according to the present invention will be described. In this embodiment, the configuration of the heat pump cycle device, the refrigerant circuit, the flow of control of the allowable maximum rotational speed of the compressor, and the effect of controlling the allowable maximum rotational speed of the compressor are the same as in the first embodiment. Since there is, explanation is omitted. The difference from the first embodiment is that the water temperature is used instead of the condensing pressure, and the allowable maximum rotation speed of the compressor is changed according to the water temperature.

  In the heat pump cycle apparatus 100 shown in FIG. 1, when the pressure sensor 30 is not provided, the condensation pressure cannot be detected, so the water temperature corresponding to the condensation pressure (the water temperature uses the value detected by the inlet side temperature sensor 24). ), The compressor rotation speed table B shown in FIG. 4 is stored in the storage unit of the control means 10 and the allowable maximum rotation speed of the compressor 1 is controlled. In this compressor rotation speed table B, the allowable maximum rotation speed (unit: rps) of the compressor 1 is determined corresponding to the water temperature and the outside air temperature during the heating operation in the low outside air temperature region. The item is the outside air temperature (unit: ° C). In this embodiment, the low outside air temperature region is a region where the outside air temperature is −15 ° C. or less, and the outside air temperature below −15 ° C. is divided every 5 ° C. to form an outside air temperature range.

  The maximum allowable number of rotations of the compressor 1 is defined in accordance with each outside air temperature range for each of “water temperature: less than 35 ° C.” and “water temperature: 35 ° C. or more”, and the water temperature is less than 35 ° C. The maximum allowable number of rotations of the compressor 1 in each outside air temperature range is 80 rps when the outside air temperature is less than −20 ° C., and when the outside air temperature is −20 ° C. or more and less than −15 ° C. and −15 ° C. or more. The upper limit number of rotations of the compressor 1 is 90 rps. When the water temperature is 35 ° C. or higher, the allowable maximum rotational speed of the compressor 1 is 90 rps, which is the upper limit rotational speed of the compressor 1, regardless of the outside air temperature range.

  In addition, the value of each allowable maximum number of rotations associated with the water temperature and the outside air temperature range, which is defined in the compressor rotation number table B, is obtained in advance by a test or the like. In addition, the control means 10 stores a table in which the water temperature and the condensation pressure, which have been obtained in advance by a test or the like, are associated with each other (for example, a table in which the condensation pressure is 2.1 MPa when the water temperature is 35 ° C.) I remember it.

  The operation of the heat pump cycle apparatus 100 storing the compressor rotation speed table B described above is as follows. When the user operates the remote controller or the like or starts the heating operation of the heat pump cycle apparatus 100 by starting the timer operation, the control means 10 detects the current water temperature detected by the inlet side water temperature sensor 24 and the outside air temperature sensor. The current outside air temperature detected at 21 is extracted. The control means 10 refers to the compressor rotation speed table B in FIG. 4 and determines the maximum allowable rotation speed of the compressor 1 corresponding to the extracted water temperature and outside air temperature. And the control means 10 controls the rotation speed of the compressor 1 within the allowable maximum rotation speed in accordance with the operation load of the indoor unit 11 and the like.

  As described above, when the heat pump cycle apparatus 100 is performing the heating operation, the allowable maximum number of rotations of the compressor 1 is set according to the water temperature and the outside air temperature, and further, less than the predetermined water temperature and less than the outside air temperature ( In this embodiment, when the water temperature is less than 35 ° C. and the outside air temperature is less than −20 ° C., the water temperature is less than 35 ° C. and the outside air temperature is − Since the allowable maximum number of revolutions of the compressor 1 is set lower than the case where the temperature is 20 ° C. or higher, or the water temperature is 35 ° C. or higher), the suction pressure of the compressor 1 becomes lower at low outside air temperature. The value can be kept below the value, and the durability of the compressor 1 can be improved.

  Further, when both the water temperature and the outside air temperature are equal to or higher than a predetermined value, the operation of the compressor 1 is allowed by allowing the compressor 1 to increase to the upper limit number of rotations of 90 rps without limiting the allowable maximum number of rotations. Efficient heating operation can be performed by maximizing the capability and achieving the target temperature that is the target temperature even in the low outside air temperature region.

  In the embodiment described above, in the compressor rotation speed table B of FIG. 4, the case where the allowable maximum rotation speed of the compressor 1 is defined in two cases where the water temperature is less than 35 ° C./more is described. However, this is three or more, for example, the water temperature is less than 35 ° C./35° C. or more and less than 60 ° C./60° C. or more (60 ° C. corresponds to the upper limit value of the discharge pressure individually determined for the compressor 1, for example. The allowable maximum number of rotations of the compressor 1 may be defined in three cases of (water temperature).

  Moreover, in the compressor rotation speed table B of FIG. 4, the outside air temperature range is set every 5 ° C. However, even if the range width is changed, for example, the outside air temperature range is set every 4 ° C. Good. Further, in the compressor rotation speed table B in FIG. 4, the allowable maximum rotation speed of the compressor 1 is all 90 rps except when the water temperature is less than 35 ° C. and the outside air temperature is less than −20 ° C. The allowable maximum rotational speed of the compressor 1 when the temperature is −20 ° C. or higher and lower than −15 ° C. is 90 rps, and the allowable maximum rotational speed of the compressor 1 when the outside air temperature is −15 ° C. or higher is 85 rps. The allowable maximum number of rotations of the compressor 1 that is different in a plurality of outside air temperature ranges may be set.

  Further, in the compressor rotation speed table B of FIG. 4, the allowable maximum rotation speed of the compressor 1 is uniformly set for a temperature range where the outside air temperature is −15 ° C. or higher and a temperature range lower than −20 ° C. However, for the temperature range where the outside air temperature is −15 ° C. or higher and the temperature range below −20 ° C., for example, a plurality of outside air temperature ranges are set every 5 ° C., and the maximum allowable rotation of the compressor 1 is set for each. A number may be set.

  As described above, according to the present invention, when the detected condensing pressure or water temperature and the outside air temperature are each less than a predetermined value, the condensing pressure or water temperature and the outside air temperature are each a predetermined value or more. Compared to the case, the allowable maximum rotational speed of the compressor is set low. Therefore, when the condensing pressure or water temperature and the outside air temperature are low and the compressor suction pressure is low, the allowable maximum rotation speed of the compressor is lowered to control the compressor suction pressure so that it does not decrease. In addition to improving durability, when the condensing pressure or water temperature and the outside air temperature are above the specified values, compression is performed by increasing the maximum allowable rotational speed of the compressor and increasing the discharge pressure of the compressor. Efficient heating cycle operation can be performed by improving the operation capacity of the machine.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Use side heat exchanger 4 1st expansion valve 5 Outdoor heat exchanger 6 Accumulator 10 Control means 11 Indoor unit 12 Refrigerant piping 13 Water piping 14 Injection piping 15 2nd expansion valve 16 Electromagnetic on-off valve DESCRIPTION OF SYMBOLS 17 Circulation pump 20 Heat exchange temperature sensor 21 Outside air temperature sensor 22 Discharge temperature sensor 23 Refrigerant temperature sensor 24 Inlet side water temperature sensor 25 Outdoor heat exchange temperature sensor 26 Outlet side water temperature sensor 30 Pressure sensor 60 Flow of refrigerant 61 Refrigerant flow at the time of injection ON Flow 62 Water flow 100 Heat pump cycle device

Claims (4)

A heat pump cycle apparatus comprising a refrigerant circuit having a compressor, a use side heat exchanger, an expansion valve, and a heat source side heat exchanger, a condensation pressure detection means, an outside air temperature detection means, and a control means,
The control means detects the condensation pressure by the condensation pressure detection means, and detects the outside air temperature by the outside air temperature detection means,
In the low outside air temperature region, the control means is configured to reduce the compression when the detected condensation pressure and the outside air temperature are each less than a threshold value, compared to when the condensation pressure and the outside air temperature are each greater than or equal to the threshold value, respectively. A heat pump cycle device characterized in that the allowable maximum number of rotations of the machine is set low. In the heat pump cycle device according to claim 1,
The said control means has a compressor rotation speed table which memorize | stored the allowable maximum rotation speed of the said compressor corresponding to the some condensing pressure and external temperature in the said refrigerant circuit, The heat pump cycle apparatus characterized by the above-mentioned. A heat pump cycle apparatus comprising a refrigerant circuit having a compressor, a use side heat exchanger, an expansion valve, and a heat source side heat exchanger, a water temperature detection means, an outside air temperature detection means, and a control means,
The control means detects the water temperature by the water temperature detection means, and detects the outside air temperature by the outside air temperature detection means,
When the detected water temperature and the outside air temperature are each lower than the threshold value in the low outside air temperature region, the control means is configured to reduce the compressor temperature compared to the case where the water temperature and the outside air temperature are respectively equal to or higher than the threshold value. A heat pump cycle device characterized in that the allowable maximum rotational speed is set low. In the heat pump cycle device according to claim 3,
The said control means has a compressor rotation speed table which memorize | stored the allowable maximum rotation speed of the said compressor corresponding to the some water temperature and external temperature in the said refrigerant circuit, The heat pump cycle apparatus characterized by the above-mentioned.

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