JP2015148426A - Heat pump type heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type heating device capable of adjusting a circulation flow rate of a heating medium while maintaining a feeding pressure of the heating medium to a heating terminal at a value equal to or greater than a predetermine value.SOLUTION: A heat pump type heating device includes: a low order-side refrigerant circuit 10 in which a refrigerant circulates in a compressor 12, a heating medium/refrigerant heat exchanger 13, a cascade heat exchanger 14, an expansion valve 15 and an evaporator 16 in this order; a high order-side refrigerant circuit 20 in which the refrigerant circulates in a compressor 22, a heating medium/refrigerant heat exchanger 23, an expansion valve 24, the cascade heat exchanger 14 in this order; a heating medium circuit 30 which has a flow rate control valve 34 on a heating medium outlet side and a heating medium pump 33 on a heating medium inlet side of a heating terminal 31, and which is configured so as to allow a return heating medium which has passed the flow rate control valve 34 to pass through the low order-side heating medium/refrigerant heat exchanger 13 and/or the high order-side heating medium/refrigerant heat exchanger 23, and then, to send it out to the heating terminal 31 by the heating medium pump 33; and a control unit 40 which controls the heating medium pump 33 and the flow rate control valve 34.

Description

  The present invention relates to a heat pump type heating device, and more particularly to a heat pump type heating device using a dual heat pump cycle.

  As this type of device, for example, a heat pump hot water supply device described in Patent Document 1 is known. This heat pump water heater operates a high-side refrigerant circuit, a low-side refrigerant circuit, and a load circuit, and a space around a place where a radiator (that is, a heating terminal) is installed by water (hot water) circulating through the load circuit. Heating operation to warm up. In the heat pump hot water supply apparatus, the load circuit is configured to send water (hot water) heated by exchanging heat with the high-side refrigerant and the low-side refrigerant to the radiator by a circulation pump, The number of revolutions of the circulation pump is adjusted so that the hot water temperature (that is, the temperature of water (hot water) sent to the radiator) becomes the target hot water temperature. In this case, basically, the greater the difference between the target hot water temperature and the hot water temperature, the lower the number of revolutions of the circulation pump and the lower the circulating flow rate of water (hot water) in the load circuit.

JP 2012-52767 A

  However, when the rotational speed of the circulation pump is reduced, the discharge pressure, that is, the delivery pressure of water (hot water) to the radiator is also reduced. For this reason, when the circulation pump is operated at a low rotational speed, water (warm water) hardly flows through a portion of the radiator having high piping resistance, and so-called “temperature unevenness” may occur. On the other hand, if the lower limit of the number of rotations of the circulation pump is set so that the supply pressure of water (warm water) to the radiator is not insufficient, the circulation flow rate of water (warm water) in the load circuit cannot be sufficiently reduced. In some cases, it takes time for the tapping temperature to reach the target tapping temperature.

  Therefore, the present invention provides a heat pump heating device capable of adjusting the circulating flow rate of the heating medium while maintaining the delivery pressure of the heating medium such as water to the heating terminal such as a radiator to a predetermined value or more. Objective.

A heat pump heating device according to one aspect of the present invention includes a low-source side refrigerant circuit, a high-source side refrigerant circuit, a heat medium circuit, and a control unit.
The low-side refrigerant circuit is configured such that the refrigerant circulates in the order of a low-side compressor, a low-side heat medium / refrigerant heat exchanger, a cascade heat exchanger, a low-side expansion valve, and an evaporator. Yes. The high-side refrigerant circuit is configured so that the refrigerant circulates in the order of a high-side compressor, a high-side heat medium / refrigerant heat exchanger, a high-side expansion valve, and the cascade heat exchanger. The heating medium circuit is a circuit in which a heating medium circulates via a heating terminal, and is disposed on a heating medium inlet side of the heating terminal and a flow rate adjusting valve arranged on the heating medium outlet side of the heating terminal. A heat medium pump that has flowed out of the heating terminal and passed through the flow rate adjustment valve. The heat medium / refrigerant heat exchanger and the high-source side heat medium / refrigerant heat exchanger The heat medium that has passed through at least one of the low-source side heat medium / refrigerant heat exchanger and the high-source side heat medium / refrigerant heat exchanger is sent out to the heating terminal by the heat medium pump. It is configured as follows. The control unit controls the heat medium pump and the flow rate adjustment valve.

  In the heat pump heating device, the heat medium circuit in which the heat medium circulates via the heating terminal is disposed on the heat medium inlet side of the heating terminal and the flow rate adjustment valve disposed on the heat medium outlet side of the heating terminal. The flow rate adjusting valve and the heat medium pump are controlled by the control unit. Thereby, the temperature of the heat medium sent out to a heating terminal can be rapidly raised by decreasing the rotation speed of a heat medium pump and reducing a heat medium circulation amount. In addition, for example, if the rotational speed of the heat medium pump is decreased, the heat medium pump rotation is reduced when the discharge pressure of the heat medium pump, that is, the supply pressure of the heat medium to the heating terminal is insufficient or may be. By operating the flow regulating valve in the closing direction while maintaining the number, it is possible to reduce the circulating amount of the heating medium while maintaining or increasing the delivery pressure of the heating medium to the heating terminal. It is possible to achieve both rapid rise and suppression of occurrence of temperature unevenness in the heating terminal.

It is a circuit diagram which shows the heat pump type heating apparatus by embodiment. It is a figure which shows an example of the change of the operating point of the pump (heat medium pump) by the action | operation of a flow regulating valve. It is a flowchart which shows control of the flow regulating valve which a control part implements.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a circuit diagram of a heat pump heating device according to an embodiment of the present invention.
The heat pump heating device according to the present embodiment uses a dual heat pump cycle. As shown in FIG. 1, a low-side refrigerant circuit 10 through which a low-temperature side refrigerant circulates and a high-side refrigerant through which a high-temperature side refrigerant circulates. The former side refrigerant circuit 20, the heat medium circuit 30 in which a heat medium circulates, and the control part 40 which controls each component of the said heat pump type heating apparatus are included.
In the present embodiment, a CO ₂ refrigerant is used as the low-side refrigerant and the high-side refrigerant, and an antifreeze liquid is used as the heat medium. However, the present invention is not limited to this, and a refrigerant other than the CO ₂ refrigerant may be used as the low-side refrigerant and / or the high-side refrigerant, or water may be used as the heat medium. Moreover, a panel heater, a floor heating panel, etc. correspond as a heating terminal.

  The low-source-side refrigerant circuit 10 has a refrigerant circulation path 11 through which the (low-source-side) refrigerant circulates. The refrigerant circulation path 11 includes a low-side compressor 12, a first heat medium / refrigerant heat exchanger (low-side heat medium / refrigerant heat exchanger) 13, and a refrigerant / refrigerant heat exchanger (cascade heat exchanger). 14, the low-side expansion valve 15 and the evaporator 16 are arranged in this order. In the low-side refrigerant circuit 10, the refrigerant is a low-side compressor 12, a first heat medium / refrigerant heat exchanger 13, a refrigerant / refrigerant heat exchanger 14, a low-side expansion valve 15, and an evaporator 16. The heat pump cycle is executed by circulating in this order. That is, the refrigerant (on the low side) is compressed by the low side compressor 12 to be in a high-temperature and high-pressure state, and the heat medium and heat circulating in the heat medium circuit 30 in the first heat medium / refrigerant heat exchanger 13. After that, the refrigerant / refrigerant heat exchanger 14 exchanges heat with the refrigerant circulating in the high-side refrigerant circuit 20 (high-side refrigerant). Next, the refrigerant is expanded by the low-side expansion valve 15 to become a low-temperature and low-pressure state, evaporates by absorbing heat from the outside air in the evaporator 16, and then (re) supplied to the low-side compressor 12. The

Here, in the present embodiment, the low-side refrigerant circuit 10 includes a refrigerant that flows between the refrigerant / refrigerant heat exchanger 14 and the low-side expansion valve 15, an evaporator 16, and the low-side compressor 12. An internal heat exchanger 17 for exchanging heat with the refrigerant flowing between them is provided. Thereby, the temperature of the refrigerant | coolant supplied to the low original side compressor 12 can be raised, and the increase in the compression ratio of the low original side compressor 12 and the fall of the COP (coefficient of performance) accompanying this are suppressed. .
Note that an accumulator (gas-liquid separator) 18 is provided on the refrigerant inlet side of the low-source compressor 12, and a fan 19 for blowing is provided in the evaporator 16.

The high-source side refrigerant circuit 20 has a refrigerant circulation path 21 through which the refrigerant (on the high temperature side) circulates. The refrigerant circuit 21 includes a high-side compressor 22, a second heat medium / refrigerant heat exchanger (high-side heat medium / refrigerant heat exchanger) 23, a high-side expansion valve 24, and refrigerant / refrigerant heat. The exchanger (cascade heat exchanger) 14 is arranged in this order. In the high-side refrigerant circuit 20, the refrigerant circulates in the order of the high-side compressor 22, the second heat medium / refrigerant heat exchanger 23, the high-side expansion valve 24, and the refrigerant / refrigerant heat exchanger 14. Thus, the heat pump cycle is executed. That is, the refrigerant (on the high side) is compressed by the high side compressor 22 to be in a high temperature and high pressure state, and the heat medium and heat circulating in the heat medium circuit 30 in the second heat medium / refrigerant heat exchanger 23. Exchange. Next, the refrigerant is expanded by the high-side expansion valve 24 to become a low-temperature and low-pressure state, and absorbs heat from the refrigerant (low-side refrigerant) circulating in the low-side refrigerant circuit 10 in the refrigerant / refrigerant heat exchanger 14. Then, it evaporates and is (re) supplied to the high-end compressor 22.
As with the low-side refrigerant circuit 10, an accumulator (gas-liquid separator) 25 is provided on the refrigerant inlet side of the high-side compressor 22.

The heat medium circuit 30 has a heat medium circulation path 32 that circulates the heat medium via the heating terminal 31. In the heating medium circulation path 32, a pump (heating medium pump) 33 for sending the heating medium to the heating terminal 31 is provided on the heating medium inlet side of the heating terminal 31, and the heating medium outlet side of the heating terminal 31. Is provided with a flow rate adjusting valve 34 that can adjust the flow rate of the heat medium flowing out from the heating terminal 31. In the heat medium circuit 30, the pump 33 sends out the heat medium to the heating terminal 31 so that the heat medium circulates through the heating terminal 31 and opens the rotation speed and / or flow rate adjustment valve 34 of the pump 33. The circulating flow rate of the heating medium is adjusted according to the degree. Here, the heat medium sent to the heating terminal 31 by the pump 33 is referred to as “outward heat medium”, and the heat medium that passes through the heating terminal 31 and flows out of the heating terminal 31 is referred to as “return heat medium”.
In the present embodiment, it is assumed that the flow rate adjustment valve 34 is fully open during normal times.

  Further, the heat medium circulation path 32 is branched into two flow paths (a low flow path 32a and a high flow path 32b) on the downstream side of the flow rate adjustment valve 34 in the flow direction of the return heat transfer medium. The return heat medium that has passed through the flow rate adjustment valve 34 is transferred to the first heat medium / refrigerant heat exchanger 13 of the low-source side refrigerant circuit 10 and the second heat medium / refrigerant heat exchanger 23 of the high-source side refrigerant circuit 2. It is comprised so that it can be made to shunt. In this embodiment, the branch point of the return heat medium that has passed through the flow rate adjustment valve 34, in other words, a branch point where the heat medium circulation path 32 branches into the low-source side flow path 32a and the high-source side flow path 32b. According to the opening degree, the part includes a flow rate of the diverted flow to the low-source side flow path 32a (that is, the first heat medium / refrigerant heat exchanger 13) and the high-source side flow path 32b (that is, the second heat medium). / A three-way valve 35 is provided that can adjust the flow rate of the diverted flow to the refrigerant heat exchanger 23).

  The low-source side channel 32a and the high-side channel 32b are respectively connected to a buffer tank 36 disposed on the heat medium suction side of the pump 33, and the buffer tank 36 and the pump 33 are a single channel 32c. Connected by. Therefore, the flow is divided into the low flow channel 32a and divided into the high flow channel 32b and the divided heat medium after the first heat medium / refrigerant heat exchanger 13 exchanges heat with the low flow medium. The diverted heat medium after heat exchange with the high-side refrigerant in the second heat medium / refrigerant heat exchanger 22 joins in the buffer tank 36 and is sent out to the heating terminal 31 by the pump 33 after joining. Become. In this case, the two divided heat transfer media are joined in the buffer tank 36, but are joined before the buffer tank 36 (before reaching the buffer tank 36) and flow into the buffer tank 36 after joining. It may be configured.

Output signals of various sensors are input to the control unit 40, and the control unit 40, based on the output signals of the various sensors, each component of the heat pump heating device, specifically, the low-source side refrigerant The low-end compressor 12 and the low-end expansion valve 15 in the circuit 10, the high-end compressor 22 and the high-end expansion valve 24 in the high-end refrigerant circuit 20, the pump 33 in the heat medium circuit 30, and the flow rate adjustment valve 34. And the three-way valve 35 is controlled.

  In the present embodiment, the various sensors include the outside air temperature sensor 51 that detects the outside air temperature, the low-side discharge temperature sensor 52 that detects the discharge temperature of the low-side compressor 12, and the high-side compressor 22. A high-end side discharge temperature sensor 53 that detects the discharge temperature, a first heat medium temperature sensor 54 that detects the temperature of the heat medium that has passed through the first heat medium / refrigerant heat exchanger 13, and a second heat medium / refrigerant heat exchanger. 23, a second heat medium temperature sensor 55 that detects the temperature of the heat medium that has passed through 23, a forward heat medium temperature sensor 56 that detects the temperature of the forward heat medium, a return heat medium temperature sensor 57 that detects the temperature of the return heat medium, and a pump A rotation sensor 58 for detecting the number of rotations 33 is provided.

  For example, the control unit 40 is configured so that the evaporation temperature of the refrigerant in the high-side refrigerant circuit 20 is higher than the evaporation temperature of the refrigerant in the low-side refrigerant circuit 10 and the heat pump heating device achieves a good COP. The number of revolutions of the low-side compressor 12 and / or the high-side compressor 22 is controlled. The control unit 40 controls the opening degree of the low-side expansion valve 14 and / or the high-side expansion valve 24 in accordance with the rotational speed control of the low-side compressor 12 and / or the high-side compressor 22. You may do it.

Moreover, the control part 40 controls the opening degree of the three-way valve 35 according to a heating load and its fluctuation | variation, and the heat-medium partial flow rate to the low-source side flow path 32a in the heat-medium circuit 30 and the high-source side flow path 32b. Adjust the heat medium flow rate to the. Such adjustment includes a case where all of the return heat medium that has passed through the flow rate adjustment valve 34 is caused to flow only in one of the low-side channel 32a and the high-side channel 32b. Thereby, according to a heating load and its fluctuation | variation, the heat-medium flow volume to the 1st heat medium / refrigerant heat exchanger 13 and the heat to the 2nd heat medium / refrigerant heat exchanger 23 of the high-side refrigerant circuit 2 are carried out. The medium flow rate is adjusted more appropriately, and the heat pump heating device can be operated efficiently.
Note that the heating load and its fluctuation are the target outgoing heat medium temperature (target hot water temperature) set based on the operation command of the heat pump heating device by the user, the output value of the outside air temperature sensor 51, the first heat. It can be calculated based on the output value of the medium temperature sensor 54, the output value of the second heat medium temperature sensor 55, the output value of the forward heat medium temperature sensor 56, the output value of the return heat medium temperature sensor 57, and the like.

  Further, the control unit 40 controls the rotational speed of the pump 33 in the heat medium circuit 30 based on the target forward heat medium temperature and the output value of the forward heat medium temperature sensor 56 (that is, the actual forward heat medium temperature). To do. For example, when the difference between the target forward heat medium temperature and the actual forward heat medium temperature (<target forward heat medium temperature) is greater than a predetermined temperature difference, the control unit 40 decreases the rotational speed of the pump 33. The flow rate of the heat medium circulating in the heat medium circuit 30 is decreased, thereby rapidly increasing the forward heat medium temperature to the target forward heat medium temperature.

  By the way, as described above, when the rotational speed of the pump 33 is decreased, the discharge pressure of the pump 33 is also decreased. For example, when the rotational speed of the pump 33 is significantly decreased, the heating medium is sent to the heating terminal 31. There is a possibility that the heat medium does not sufficiently flow in a portion where the pressure is insufficient and the piping resistance of the heating terminal 31 is high. On the other hand, in order to prevent this, if the lower limit of the rotation speed of the pump 33 is set, the heat medium circulation flow rate cannot be reduced sufficiently, and it takes time to raise the outgoing heat medium temperature to the target outgoing heat medium temperature. May occur.

Therefore, when the number of rotations of the pump 33 is reduced to a predetermined value, the control unit 40 controls the flow rate adjustment valve 34 in the closing direction (that is, the direction in which the opening degree is reduced). While reducing the amount of circulating heat medium, the piping resistance of the heat medium circuit 30 is increased.
For example, as shown in FIG. 2, the rotational speed of the pump 33 decreases (the operating point of the pump 33 changes from point A to point B), and the discharge pressure is the minimum required according to the heating terminal 31. When the pressure is lower than the discharge pressure, the control unit 40 controls the flow rate adjustment valve 34 in the closing direction to increase the piping resistance in the heat medium circuit 30 and change the operating point of the pump 33 from the B point to the C point. Let Thereby, without changing the number of rotations of the pump 33, while maintaining the discharge pressure of the pump 33 (the discharge pressure of the heat medium to the heating terminal 31) above the minimum discharge pressure, the amount of circulating heat medium is reduced. The outgoing heat medium temperature is quickly raised to the target outgoing heat medium temperature.

FIG. 3 is a flowchart showing the control of the flow rate adjustment valve 34 performed by the control unit 40. This flow is repeatedly performed every predetermined period.
In step S1, the rotational speed (pump rotational speed) Np of the pump 33 is detected. Such detection is performed based on the output signal of the rotation sensor 58. The control unit 40 may detect the pump rotation speed Np based on a control signal output to the pump 33 by itself, and in this case, the rotation sensor 58 can be omitted.

  In step S2, it is determined whether or not the operation flag f of the flow rate adjusting valve 34 is set, that is, whether or not the operation flag f = 1. If the operation flag f is not set (if the operation flag f = 0), the process proceeds to step S3. If the operation flag f is set (if the operation flag f = 1), the process proceeds to step S6. The operation flag f is set when the flow rate adjustment valve 34 in the fully opened state is operated (that is, when the opening degree of the flow rate adjustment valve 34 is reduced) (steps S4 and S5), and the set operation flag is set. f is canceled when the flow regulating valve 34 is fully opened (S12).

  In step S3, it is determined whether or not the pump rotation speed Np detected in step S1 is equal to or less than a first threshold value Nth1. If the pump rotation speed Np is equal to or less than the first threshold value Nth1 (Np ≦ Nth1), the process proceeds to step S4. If the pump rotation speed Np exceeds the first threshold value Nth1 (if Np> Nth1), this flow is performed. finish. The first threshold value Nth1 is the number of rotations of the pump 33 at which the discharge pressure of the pump 33 is equal to or lower than the minimum discharge pressure, and is set based on the performance of the pump 33, the piping load of the heating terminal 31, and the like.

In step S4, the flow rate adjustment valve 34 is closed by a predetermined opening. As a result, the flow path area of the heat medium circuit 32 is reduced, the piping resistance of the heat medium circuit 30 is increased, and the amount of heat medium circulation in the heat medium circuit 30 is decreased.
In step S5, the operation flag f is set (operation flag f = 1).

  In step S6, as in step S3, it is determined whether or not the pump speed Np detected in step S1 is equal to or less than the first threshold value Nth1. If the pump speed Np is equal to or lower than the first threshold value Nth1 (Np ≦ Nth1), the process proceeds to step S7. If the pump speed Np exceeds the first threshold value Nth1 (if Np> Nth1), the process proceeds to step S9. move on.

In step S7, it is determined whether or not the opening degree of the flow control valve 34 is a preset minimum opening degree. If the opening degree of the flow control valve 34 is the minimum opening degree, this flow is terminated. If the opening degree of the flow control valve 34 is not the minimum opening degree, the process proceeds to step S8.
In step S8, as in step S4, the flow rate adjustment valve 34 is closed by a predetermined opening.

On the other hand, in step S9, it is determined whether or not the pump rotation speed Np detected in step S1 is equal to or greater than a second threshold value Nth2 (> first threshold value Nth1). If the pump speed Np is equal to or greater than the second threshold value Nth2 (Np ≧ Nth2), the process proceeds to step 10, and if the pump speed Np is less than the second threshold value Nth2 (Np <Nth2), this flow is terminated.
In step S10, the flow rate adjustment valve 34 is opened by a predetermined opening. This predetermined amount may be the same as or different from the predetermined amount in step S4 or step S8.

  In step S11, it is determined whether or not the flow rate adjustment valve 34 is fully open. If the flow rate adjustment valve 34 is not fully open, this flow ends. If the flow rate adjustment valve 34 is fully open, the operation flag f is canceled in step S12, that is, the operation flag f = 0, and this flow ends. .

  As described above, in the heat pump heating device according to the present embodiment, the control unit 40 further describes the target outgoing heat medium temperature based on the temperature of the outgoing heat medium sent to the heating terminal 31 by the pump 33. The rotational speed Np of the pump 33 is controlled based on the temperature difference between the actual heat transfer medium and the actual heat transfer medium. On the other hand, when the rotational speed Np of the pump 33 decreases to the first threshold value Nth1, the flow control valve 34 is closed. (See steps S3 and S4). Thereby, while maintaining the delivery pressure of the heating medium that can flow the heating medium over the entire heating terminal 31, the amount of circulation of the heating medium in the heating medium circuit 30 is reduced and the temperature of the outgoing heating medium is quickly increased. The temperature can be raised to the target heat transfer medium temperature.

  Further, after the control unit 40 controls the rotational speed Np of the pump 33 to the first threshold value Nth1 and closes the flow rate control valve 34, the rotational speed Np of the pump 33 is set to the second threshold value Nth2 (> the above-mentioned value). When the first threshold value Nth1) is reached, the flow control valve 34 is controlled to open. Thereby, the excessive piping load of the heat medium circuit 30 can be reduced while suppressing the occurrence of hunting in the opening / closing control of the flow control valve 34.

  Here, the control unit 40 controls the flow rate control valve 34 by a predetermined opening degree, that is, the opening degree of the flow rate control valve 34 both when controlling the flow rate control valve 34 in the closing direction and when controlling the flow rate control valve 34 in the opening direction. Control in a stepwise manner (see steps S8 and S10). Thereby, the rapid change of the piping resistance of the heat medium circuit 30 and the heat medium circulation amount can be suppressed, and the stable operation of the heat pump heating device can be realized.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that further modifications and the like can be made based on the technical idea of the present invention. .

  For example, in the above-described embodiment, the heat medium circuit 30 uses the return heat medium that has passed through the flow control valve 34 as the first heat medium / refrigerant heat exchanger 13 of the low-side refrigerant circuit 10 and the high-side refrigerant circuit. The second heat medium / refrigerant heat exchanger 23 is divided into two. However, the present invention is not limited to this, and after the return heat medium that has passed through the flow control valve 34 has passed through the second heat medium / refrigerant heat exchanger 23 of the high-source side refrigerant circuit 2, You may form so that the 1st heat medium / refrigerant heat exchanger 13 of the refrigerant circuit 10 may be passed. In this case, instead of the low-side circuit 32a and the high-side circuit 32b, the flow control valve 34 is connected to the pump 33 via the first heat medium / refrigerant heat exchanger 14 and the second heat medium / refrigerant heat exchanger 23. The three-way valve 35 and the buffer tank 36 are not necessary.

In the above-described embodiment, the three-way valve 35 provided in the return heat medium diverting portion that has passed through the flow rate adjusting valve 34 supplies the low-source side flow path 32a (first heat medium / refrigerant heat exchanger 13). The diversion flow rate and the diversion flow rate to the high-end side flow path 32b (second heat medium / refrigerant heat exchanger 23) are adjusted. However, the present invention is not limited to this, and the heat medium circuit 30 is configured such that the flow rate of the diverted flow to the low-source side flow channel 32a (first heat medium / refrigerant heat exchanger 13) and the high-source side flow channel 32b (second heat medium). It is only necessary to have a diversion controller capable of adjusting the diversion flow rate to the refrigerant heat exchanger 23). For example, a flow control valve may be provided in the low-source side channel 32a and / or the high-side channel 32b.
Furthermore, in the above-described embodiment, the low-side refrigerant circuit 10 includes the internal heat exchanger 17, but this may be omitted.

  DESCRIPTION OF SYMBOLS 10 ... Low side refrigerant circuit, 11 ... Refrigerant circuit, 12 ... Low side compressor, 13 ... 1st heat medium / refrigerant heat exchanger (low side heat medium / refrigerant heat exchanger), 14 ... Refrigerant / Refrigerant heat exchanger (cascade heat exchanger), 15 ... low-side expansion valve, 16 ... evaporator, 17 ... internal heat exchanger, 20 ... high-side refrigerant circuit, 21 ... refrigerant circuit, 22 ... high-side Compressor, 23 ... second heat medium / refrigerant heat exchanger (high-side heat medium / refrigerant heat exchanger), 24 ... high-side expansion valve, 30 ... heat medium circuit, 31 ... heating terminal, 32 ... heat medium Circulation path, 32a ... Low source side channel, 32b ... High source side channel, 33 ... Pump (heat medium pump), 34 ... Flow control valve, 35 ... Three-way valve, 36 ... Buffer tank, 40 ... Control unit, 56 ... Walking medium temperature sensor, 58 ... Rotation sensor

Claims (6)

A low-side compressor circuit, a low-side heat medium / refrigerant heat exchanger, a cascade heat exchanger, a low-side expansion valve, and a low-side refrigerant circuit in which the refrigerant circulates in that order,
A high-end side refrigerant circuit in which refrigerant circulates in the order of a high-end side compressor, a high-end side heat medium / refrigerant heat exchanger, a high-end side expansion valve, and the cascade heat exchanger;
A heating medium circuit in which a heating medium circulates via a heating terminal, the flow rate adjusting valve arranged on the heating medium outlet side of the heating terminal, and the heating medium pump arranged on the heating medium inlet side of the heating terminal And the heat medium flowing out of the heating terminal and passing through the flow rate adjusting valve passes through at least one of the low-source side heat medium / refrigerant heat exchanger and the high-source side heat medium / refrigerant heat exchanger. And the heat medium that has passed through at least one of the low-side heat medium / refrigerant heat exchanger and the high-side heat medium / refrigerant heat exchanger is sent out to the heating terminal by the heat medium pump. Heating medium circuit,
A control unit for controlling the heat medium pump and the flow rate adjusting valve;
Including a heat pump type heating device.   The heat medium circuit divides the heat medium that has passed through the flow rate adjusting valve into the low-source-side heat medium / refrigerant heat exchanger and the high-source-side heat medium / refrigerant heat exchanger, and the low-source-side heat A structure in which the divided heat medium that has passed through the medium / refrigerant heat exchanger and the divided heat medium that has passed through the high-source side heat medium / refrigerant heat exchanger are merged and then sent to the heating terminal by the heat medium pump. The heat pump type heating device according to claim 1, wherein   The said heat-medium circuit has a shunt control valve which can adjust the shunt flow rate to the said low original side heat medium / refrigerant heat exchanger, and the shunt flow rate to the said high original side heat medium / refrigerant heat exchanger. 2. A heat pump heating device according to 2.   The control unit controls the number of revolutions of the heat medium pump based on the temperature of the forward heat medium sent to the heating terminal, while the number of revolutions of the heat medium pump decreases to a first predetermined value. The heat pump type heating apparatus according to any one of claims 1 to 3, wherein the flow control valve is controlled in a closing direction.   The controller controls the direction of opening the flow rate adjusting valve when the rotation speed of the heat medium pump decreases to the first predetermined value and then becomes a second predetermined value larger than the first predetermined value. The heat pump type heating device according to claim 4.   The heat pump heating device according to claim 4 or 5, wherein the control unit controls the opening degree of the flow rate adjustment valve step by step by a predetermined amount.