JP7125888B2 - Cooling exhaust heat hot water storage device - Google Patents

Description

The present invention relates to a cooling exhaust heat hot water storage device for heating hot water in a hot water storage tank.

Conventionally, as a hot water storage type water heater, as described in Patent Document 1, a heat pump device for high temperature boiling and a heat pump device for medium temperature boiling are provided, and high temperature water from the heat pump device for high temperature boiling is supplied to the upper part of the hot water storage tank. On the other hand, there is a type in which medium-temperature hot water is supplied from a medium-temperature boiling heat pump device to an intermediate portion in the vertical direction of a hot water storage tank. By returning the intermediate hot water with a low temperature to the middle portion of the hot water storage tank instead of the upper portion, the high temperature water layer in the upper portion of the hot water storage tank, which is used for reheating the bath, for example, is not broken. can do.

JP 2009-002585 A

In the configuration of the prior art, it is conceivable to heat the hot water in the hot water storage tank by using the exhaust heat during the cooling operation instead of the heat pump for boiling the medium temperature. That is, in this case, the indoor heat exchanger and the refrigerant side of the water-refrigerant heat exchanger are connected to form a refrigerant circulation circuit, and the water side of the water-refrigerant heat exchanger and the hot water storage tank are connected to form a hot water circulation circuit. configure. As a result, the heat absorbed from the indoor heat exchanger during the cooling operation can be radiated to the water side in the water-refrigerant heat exchanger, and the hot water in the hot water storage tank can be heated.

Here, when hot water is heated (boiling to medium-temperature water) using cooling exhaust heat as described above, the number of revolutions of the circulation pump of the hot water circulation circuit is usually detected by an appropriate detection means. Feedback control is performed so that the actual boiling temperature of the hot water detected by is matched with the target boiling temperature. As a result, when the output (cooling output) of the refrigerant circulation circuit increases, the rotation speed of the circulation pump increases in order to maintain the actual boiling temperature at the target boiling temperature, and the flow rate of hot water increases. As a result, the output (boiling output) in the hot water circulation circuit increases. When the cooling output decreases, the rotation speed of the circulation pump decreases to maintain the actual boiling temperature, and the boiling output also decreases.

When the boiling output increases or decreases in conjunction with the cooling output in this way, when the cooling output increases to a certain extent, the boiling output also increases and the flow rate of the middle-temperature water increases. As a result, the medium-temperature water is returned into the hot water tank at a relatively high speed, and breaks the boundary layer between the upper high-temperature water layer and the middle medium-temperature water layer in the hot water storage tank. There was a problem that there was a risk of it being lost.

In order to solve the above problems, in claim 1 of the present invention, a water-refrigerant heat exchanger that functions as a condenser that exchanges heat between refrigerant and water, and heat exchange between the refrigerant and indoor air. an indoor heat exchanger functioning as an evaporator; the water-refrigerant heat exchanger; a compressor connected to the indoor heat exchanger; A hot water circulation circuit is formed by annularly connecting the water side and the hot water storage tank with hot water piping, and the refrigerant side of the water refrigerant heat exchanger, the compressor, and the indoor heat exchanger are connected by refrigerant piping. The indoor heat exchanger is connected to form a refrigerant circulation circuit, the inlet side of the water-refrigerant heat exchanger communicates with the discharge side of the compressor, and the outlet side communicates with the suction side of the compressor. In a cooling exhaust heat hot water storage device, the outlet side of the water-refrigerant heat exchanger communicates with the inlet side, and hot water heated by the water-refrigerant heat exchanger is supplied to the hot water storage tank, boiling temperature detection means for detecting the actual boiling temperature of hot water flowing out from the water side of the water-refrigerant heat exchanger to the hot water pipe; a circulation pump for circulating the hot water in the hot water pipe; pump control means for increasing or decreasing the number of revolutions of the circulation pump in accordance with the deviation between the actual boiling temperature detected by the detecting means and a predetermined target boiling temperature; and a return pipe connected to an intermediate portion in the vertical direction of the hot water storage tank for returning hot water to the inside of the hot water storage tank. By increasing the rotation speed of the circulation pump until the predetermined flow rate is reached, the actual boiling temperature detected by the boiling temperature detecting means is controlled to be the target boiling temperature. Rotational speed increase processing; Flow rate stabilization processing for controlling the pump flow rate to be substantially constant while increasing and correcting the target boiling temperature after the pump flow rate reaches the predetermined flow rate; be.

Further, in claim 2, the flow rate stabilization process includes a first processing period in which the pump flow rate is kept substantially constant while increasing the actual boiling point temperature, and during the first processing period, the actual boiling point temperature is After reaching the corrected target boiling point temperature, a second processing period in which the pump flow rate is kept substantially constant in that state, and after the second processing period, the actual boiling point temperature is decreased while the pump and a third processing period in which the flow rate is kept substantially constant.

Further, in claim 3, the pump control means reduces the rotation speed of the circulation pump when the actual boiling point temperature decreases and reaches the target boiling point temperature before performing the increase correction in the flow rate stabilization process. By reducing the actual boiling temperature detected by the boiling temperature detection means, the rotational speed reduction process is executed to control the actual boiling temperature to become the target boiling temperature.

In a fourth aspect of the present invention, the pump control means includes flow rate determination means for determining the actual pump flow rate of the circulation pump, and in the rotation speed increasing process, the pump flow rate determined by the flow rate determination means is determined by the The rotation speed of the circulation pump is increased until the predetermined flow rate is reached, and in the flow rate stabilization process, the pump flow rate determined by the flow rate determination means is controlled to be kept substantially constant .

Moreover, in claim 5, the flow rate determining means includes a rotation speed sensor provided in the circulation pump or a flow rate sensor provided in the hot water pipe.

In a sixth aspect of the present invention, the pump control means includes flow rate limiting means for limiting the upper limit of the actual pump flow rate by the circulation pump to the predetermined flow rate, and in the rotation speed increasing process, the flow rate limiting means limits the flow rate. The rotation speed of the circulation pump is increased until the flow rate of the pump in the state where the flow rate reaches the predetermined flow rate. control.

Moreover, in claim 7, the flow rate limiting means is a constant flow valve provided in the hot water pipe.

Further, in claim 8, a heat pump heat exchanger connected in parallel with the water-refrigerant heat exchanger for exchanging heat between the refrigerant and the outside air, and a heat pump heat exchanger connected to the discharge side of the compressor An air exhaust heat cooling mode in which the inlet side of the heat exchanger is communicated and the outlet side of the heat pump heat exchanger is communicated with the inlet side of the indoor heat exchanger, and the water refrigerant heat is communicated with the discharge side of the compressor. A mode switching is possible between a cooling mode using waste heat in which the inlet side of the exchanger is communicated and the outlet side of the water-refrigerant heat exchanger is communicated with the inlet side of the indoor heat exchanger to perform the hot water supply process. and means.

According to claim 1 of the present invention, the indoor heat exchanger has the inlet side of the water-refrigerant heat exchanger communicated with the discharge side of the compressor and the outlet side of the water refrigerant heat exchanger communicated with the suction side of the compressor. The outlet side of the water-refrigerant heat exchanger communicates with the inlet side. The high-temperature, high-pressure refrigerant gas discharged from the compressor releases heat in the water-refrigerant heat exchanger (functioning as a condenser) and condenses to become liquid refrigerant. absorbs heat and returns to the compressor.

On the other hand, at this time, the water side of the water-refrigerant heat exchanger is annularly connected to the hot water storage tank via the hot water pipe to form a hot water circulation circuit. As described above, a refrigeration cycle is formed in the path of compressor discharge side→water-refrigerant heat exchanger→indoor heat exchanger→compressor suction side. The heat of the hot gas discharged from the compressor after absorbing heat from the air is radiated to the water side in the water-refrigerant heat exchanger (functioning as a condenser). As a result, the heat received by the heat exchange can be used to heat hot water (hot water supply process) to the hot water storage tank through the hot water pipe.

At this time, the hot water pipe is provided with a circulating pump and boiling temperature detecting means. The rotation speed of the circulating pump is controlled by the pump control means according to the deviation between the actual boiling temperature of hot water detected by the boiling temperature detecting means and a predetermined target boiling temperature. Feedback control is performed so that As a result, when the output (cooling output) of the refrigeration cycle increases, the rotation speed of the circulation pump increases in order to maintain the actual boiling point temperature at the target boiling point temperature, and the flow rate of hot water increases, causing the hot water pipe to The output (boiling output) increases. When the cooling output decreases, the rotation speed of the circulation pump decreases to maintain the actual boiling temperature, and the boiling output also decreases.

At this time, the hot water circulation circuit is provided with a return pipe, and the hot water from the water side of the water-refrigerant heat exchanger is returned to the middle portion in the height direction of the hot water storage tank via the return pipe. This has the following significance. That is, since the boiling output increases or decreases according to the magnitude of the cooling output as described above, the target boiling temperature of hot water is usually relatively low (for example, 45° C.) in order to maintain a high cooling COP. etc. So-called medium temperature water) is set. At this time, in the upper part of the hot water storage tank, hot water having a temperature higher than the above (so-called high-temperature water), which is boiled separately from the hot water supply process using the cooling exhaust heat, is stored. Therefore, as described above, by returning the medium-temperature hot water having a relatively low temperature not to the upper part of the hot water storage tank but to the middle part in the height direction of the hot water storage tank, It is possible not to destroy a layer of said hot water.

Here, since the boiling output increases and decreases in conjunction with the cooling output as described above, when the cooling output increases to a certain extent, the boiling output also increases and the flow rate of the intermediate water increases. . As a result, the medium-temperature water is returned into the hot water tank at a relatively high speed, and there is a risk of destroying the boundary layer between the upper high-temperature water layer and the intermediate medium-temperature water layer in the hot water storage tank. There is

Therefore, according to claim 1, the pump control means executes the rotation speed increasing process and the flow rate stabilization process. That is, for a while after the start of the hot water supply process (until the flow rate of the circulation pump reaches the predetermined flow rate), the rotation speed of the circulation pump is gradually increased to increase the actual boiling point temperature of the hot water. , the target boiling temperature is maintained (rotation speed increasing process).

After the pump flow rate reaches the predetermined flow rate, the target boiling point temperature is corrected to increase , and the actual boiling point temperature is allowed to increase up to the target boiling point temperature corrected to increase. As a result, even if the cooling output further increases after the pump flow rate reaches the predetermined flow rate, the corresponding increase in the boiling power output is absorbed by the increase in the actual boiling temperature. The predetermined flow rate can be kept substantially constant (flow rate stabilization process).

As a result, since a certain upper limit can be set for the speed of medium-temperature water returning into the hot water tank through the return pipe, the boundary layer between the high-temperature water layer and the medium-temperature water layer in the hot water tank can be prevented from being destroyed.

Further, according to claim 2, for example, by appropriately setting the target boiling point temperature after correction, in the flow rate stabilization process of the pump control means, the cooling output increases, thereby increasing the actual boiling point temperature. period (first processing period), after which the cooling output stops rising and becomes constant and the actual boiling temperature reaches the target boiling temperature (second processing period), after which the cooling output decreases By decreasing, the actual boiling point temperature decreases in order of the period (third processing period), and the pump flow rate can be kept substantially constant during that period.

In addition, according to claim 3, when the actual boiling point temperature has decreased to the target boiling point temperature before the increase correction, the original control is resumed, and the rotation speed of the circulation pump is decreased while the actual boiling point temperature is reduced. is controlled to be the original (before correction) target boiling temperature. As a result, it is possible to return the cooling COP, which had been reduced (due to the increase correction of the target boiling temperature), to the original desired high level in the flow rate stabilization process.

Further, according to claim 4, the flow rate determination means determines the pump flow rate, and the rotation speed increasing process and the flow rate stabilization process are performed based on the determined pump flow rate. As a result, the pump flow rate can be reliably kept substantially constant after the target boiling temperature is corrected to increase.

Further, according to claim 5, the rotational speed increasing process and the flow rate stabilization process are accurately performed based on the flow rate determination (detection) result of the rotation speed sensor or the flow rate determination (detection) result of the flow sensor. can be done.

Further, according to claim 6, the rotation speed increasing process and the flow rate stabilization process are performed using the flow rate limiting function of the flow rate limiting means. As a result, the pump flow rate can be reliably kept substantially constant .

Further, according to claim 7, by using the constant flow discharge function of the constant flow valve, the rotational speed increasing process and the flow constant process can be performed with high reliability and accuracy.

Also, according to claim 8, the cooling operation can be performed in two modes (atmospheric exhaust heat cooling mode and exhaust heat utilizing cooling mode). In the exhaust heat utilization cooling mode, the path of compressor discharge side→water refrigerant heat exchanger→indoor heat exchanger→compressor suction side compressor discharge side→water refrigerant heat exchanger→indoor heat exchanger → A refrigeration cycle is realized in the path on the compressor suction side.

On the other hand, in the atmospheric exhaust heat cooling mode, the indoor heat exchanger as the indoor heat exchanger communicates the inlet side of the heat pump heat exchanger with the discharge side of the compressor and communicates the outlet side with the suction side of the compressor. The outlet side of the heat pump heat exchanger communicates with the inlet side of the heat exchanger. In this case, the high-temperature, high-pressure refrigerant gas discharged from the compressor radiates heat to the outside air in the heat pump heat exchanger (functioning as a condenser), condenses into liquid refrigerant, and then evaporates in the indoor heat exchanger (functioning as an evaporator). By doing so, it is possible to realize a normal cooling operation in which heat is absorbed from the indoor air and returned to the compressor.

1 is a circuit configuration diagram of an entire cooling exhaust heat hot water storage device according to an embodiment of the present invention; Functional configuration diagram of the outdoor unit control unit Functional configuration diagram of the heat exchange control unit Functional configuration diagram of the indoor unit control unit Functional configuration diagram of hot water storage controller Functional block diagram of the heat pump control unit Diagram explaining operation during normal cooling operation using exhaust heat from the atmosphere Diagram for explaining the operation during hot water supply operation using exhaust heat Diagram explaining the operation during boiling operation Graph showing the behavior of the target boiling temperature over time, the graph showing the behavior of the boiling temperature over time, and the behavior of the boiling power output, cooling output, and pump flow rate over time after starting the hot water supply operation using waste heat. A graph diagram representing FIG. 4 is a flow chart for explaining a processing procedure executed by an outdoor unit control unit, a hot water storage control unit, an indoor unit control unit, a heat exchange control unit, and a heat pump control unit;

An embodiment of the present invention will be described below with reference to FIGS. 1 to 11. FIG.

FIG. 1 shows an overall circuit configuration of a heat pump water heater 1 (corresponding to a cooling exhaust heat hot water storage device) with a cooling/heating function according to the present embodiment.

1, the heat pump water heater 1 of the present embodiment includes a hot water storage unit 100 having a hot water storage tank 2, an outdoor unit 300 as an air conditioner outdoor unit, an indoor unit 200 as an air conditioner indoor unit, and a heat exchange unit. 400 and a heat pump unit 500 .

The heat exchange unit 400 is a water-refrigerant heat exchanger that has a refrigerant-side flow path 15b and a water-side flow path 15a for circulating the refrigerant, and exchanges heat between the high-temperature and high-pressure refrigerant and the hot water in the hot water storage tank 2. 15 and a boiling pump 19 (corresponding to a circulation pump). That is, the water-side flow path 15a of the water-refrigerant heat exchanger 15 and the hot water storage tank 2 are annularly connected by a heating supply pipe 5 and a heating return pipe 6 as hot water piping, and the hot water storage unit 100 and heat exchange are connected. A heating circulation circuit 4 is formed as a hot water circulation circuit within the unit 400 .

The heating supply pipe 5 includes a pipe 5 a and a pipe 5 b , and the pipe 5 b is connected to the lower part of the hot water storage tank 2 .

The heating return pipe 6 includes a pipe 6a, a pipe 6b, a pipe 6c, a pipe 6d (corresponding to a return pipe), and a pipe 6e. It is The pipe 6b is connected to the upper portion of the hot water storage tank 2, and the pipes 6d and 6e are branched and connected from the pipe 6c via a three-way valve 10D. The pipe 6d is connected to the middle portion of the hot water storage tank 2 in the height direction, and the pipe 6e is connected to the water supply pipe 7 that is connected to the lower portion of the hot water storage tank 2 and supplies water to the hot water storage tank 2. . A water supply bypass pipe 9 is branched from the water supply pipe 7 .

The boiling pump 19 is provided in the middle of the pipe 5a, and circulates hot water from the heating supply pipe 5 to the heating return pipe 6 through the water-side flow path 15a, while pumping hot water from the hot water storage tank 2. Circulate. The heating supply pipe 5 is provided with an incoming water temperature sensor 23 for detecting an incoming water temperature T1 (inlet temperature of hot water) flowing into the water-side flow path 15a of the water-refrigerant heat exchanger 15. The return pipe 6 is provided with a boiling-up temperature sensor 24 (as boiling-up temperature detecting means) for detecting the boiling-up temperature Tb (equivalent to the actual boiling-up temperature) flowing out from the water-side flow path 15a toward the hot water storage tank 2. equivalent) is provided.

Further, a flow rate sensor 28 (flow rate determination means) is provided. Instead of the flow rate sensor 28, the pump flow rate may be detected (determined) based on the rotation speed detected by a rotation speed sensor (corresponding to flow rate determination means in this case) provided in the boiling pump 19 itself. good.

A hot water discharge pipe 8 for discharging stored hot water is also connected to the upper portion of the hot water storage tank 2, and the hot water discharge pipe includes a pipe 8a, a pipe 8b, a pipe 8c, and a pipe 8d. The pipe 8a is connected to the upper portion of the hot water storage tank 2, and takes out relatively high temperature hot water (hereinafter simply referred to as "high temperature water" as appropriate) near the upper portion of the hot water storage tank 2 and supplies it to the mixing valve 10B. lead to The pipe 8d is connected to the middle portion in the height direction of the hot water storage tank 2, and is located in the middle portion in the vertical direction of the hot water storage tank 2 and is in a medium temperature range that is neither relatively high nor low (hereinafter referred to simply as " (referred to as “medium temperature water”) is taken out. The hot water storage tank 2 side of the pipe 8b is connected through a branch point B to the pipe 8d. The side of the pipe 8b opposite to the hot water storage tank 2 is connected to the mixing valve 10B. That is, the pipes 8a and 8b are connected to join the pipe 8c through the mixing valve 10B. The mixing valve 10B mixes the high-temperature water from the pipe 8a and the medium-temperature water from the pipes 8d and 8b at a desired ratio, and leads the mixture to the pipe 8c.

At this time, the hot water storage tank 2 side of the pipe 6d is connected to the branch point B as described above. As a result, hot water introduced into the pipe 6d from the water-side flow path 15a of the water-refrigerant heat exchanger 15 through the pipes 6a and 6c flows into the hot water storage tank 2 through the pipe 8d. returned. Note that the pipe 6d may be connected to the middle portion of the hot water storage tank 2 in the height direction independently of the pipe 8d without being connected to the pipe 8d.

The pipe 8c and the water supply bypass pipe 9 are connected so as to merge with the hot water discharge pipe 11 via the mixing valve 10A. The hot water supply pipe 11 is provided with a hot water supply temperature sensor 37 for detecting the hot water supply temperature after mixing by the mixing valve 10A. The mixing valve 10A mixes the hot water from the pipe 8c and the water from the water supply bypass pipe 9 based on the detection result of the hot water supply temperature sensor 37 to produce hot water at the hot water supply set temperature.

On the side surface of the hot water storage tank 2, there are a plurality of stored hot water temperature sensors 12 extending vertically for detecting the temperature of the hot water in the hot water storage tank 2 (hot water temperature) and for detecting the heating state of the hot water (in other words, the hot water storage state). is provided.

On the other hand, in the water-refrigerant heat exchanger 15, a refrigerant circulation circuit 30 (including refrigerant pipes 18, 25, and 26, which will be described later) capable of exchanging heat (details will be described later) with hot water in the hot water storage tank 2, It is provided over the heat exchange unit 400 , the outdoor unit 300 , and the indoor unit 200 .

That is, in the outdoor unit 300, the compressor 14 that compresses the refrigerant, the four-way valve 31, and the heat pump that selectively functions as a condenser or an evaporator by heat exchange between the refrigerant and the outside air (details will be described later). An outdoor heat exchanger 17 as a heat exchanger is connected by the refrigerant pipe 18 . The outdoor heat exchanger 17 is provided with an outdoor fan 67 for passing outside air through the outdoor heat exchanger 17 .

Specifically, the refrigerant pipe 18 includes a pipe portion 18a on the discharge side of the compressor 14, a pipe portion 18c on the suction side of the compressor 14, and a pipe portion 18c on the suction side of the compressor 14. and a pipe portion 18b connected to 18a. The refrigerant pipe 18 includes pipe portions 18d and 18e connecting the compressor 14 side of the outdoor heat exchanger 17 to the pipe portion 18c via the four-way valve 31 during the heating operation, and the outdoor heat exchanger 17. and a pipe portion 18f connected to the opposite side of the compressor 14. The piping portion 18e has a two-way valve 122, and the piping portion 18f has an expansion valve 113 with a fully closed function as a first on-off valve.

The four-way valve 31 is a valve having four ports, and of the refrigerant pipe 18, each of the two ports for the pipe portions 18b and 18d (constituting the refrigerant main path) is connected to the remaining pipe portions. It switches which of the two ports for 18a and 18c to communicate. The two ports for the piping portions 18a and 18c are connected to each other by a refrigerant subpath composed of the piping portions 18a and 18c arranged in a loop, and the compressor 14 is provided on this refrigerant subpath. ing. For example, when the four-way valve 31 is switched to the heating side, the piping portion 18a, which is the discharge side of the compressor 14, communicates with the piping portion 18b, which is the inlet side of the indoor heat exchanger 27, which will be described later. When switched to the side, the piping portion 18a is communicated with the piping portions 18d and 18e on the outdoor heat exchanger 17 side.

On the other hand, the heat exchange unit 400 is provided with a refrigerant pipe 25 that serves as a flow path for the refrigerant. ing.

Specifically, the refrigerant pipe 25 includes a pipe portion 25a that connects the pipe portion 18d and one side of the water-refrigerant heat exchanger 15 (more specifically, the refrigerant-side flow path 15b), and the water-refrigerant heat exchanger. It includes a pipe portion 25b that connects the pipe portion 18f with the other side opposite to the pipe portion 25a of the exchanger 15 (more specifically, the flow path 15b on the refrigerant side). The piping portion 25a includes a two-way valve 121 as a second on-off valve capable of opening and closing the four-way valve 31 and the one side of the water-refrigerant heat exchanger 15, and the piping portion 25b has a fully closed function. It has an expansion valve 111 with.

On the other hand, the indoor unit 200 is provided with a refrigerant pipe 26 that serves as a flow path for the refrigerant, and selectively functions as a condenser or an evaporator by heat exchange between the refrigerant and indoor air (details will be described later). ) is connected to the refrigerant pipe 26 . The indoor heat exchanger 27 is provided with an indoor fan 77 for passing the indoor air through the indoor heat exchanger 27 .

Specifically, the refrigerant pipe 26 is provided in communication with the pipe portion 18b, and the pipe portion 26a connected to the inlet side of the indoor heat exchanger 27 during heating operation or the like, and the indoor heat exchanger 27 and a pipe portion 26b that connects the outlet side of the pipe portion 27 to the pipe portion 18f during a heating operation or the like.

The heat pump unit 500 has a refrigerant-side flow path 115b and a water-side flow path 115a for circulating the refrigerant, and is capable of exchanging heat between the high-temperature and high-pressure refrigerant and the hot water in the hot water storage tank 2. An exchanger 115 and a boiling pump 119 are provided. That is, the pipe 105a branched from the three-way valve 10F provided in the pipe 5a of the heating supply pipe 5 is connected to one side (lower side in the drawing) of the water-side flow path 115a of the water-refrigerant heat exchanger 115. A pipe 106a branched from the pipe 6a of the heating return pipe 6 is connected to the other side (upper side in the drawing) of the water-side flow path 115a. A heating circulation circuit 104 as a hot water circulation circuit is formed in the heat pump unit 500 by means of piping. The boiling pump 119 is provided in the middle of the pipe 105a, and circulates hot water from the heating supply pipe 5 to the heating return pipe 6 through the water-side flow path 115a, and pumps hot water from the hot water storage tank 2. can be circulated.

The heat pump unit 500 is also provided with a refrigerant circulation circuit 130 capable of exchanging heat with hot water in the hot water storage tank 2 in the water-refrigerant heat exchanger 115 . That is, in the refrigerant circulation circuit 130, a compressor 114 that compresses refrigerant, an outdoor heat exchanger 117 that selectively functions as a condenser or an evaporator by exchanging heat between the refrigerant and the outside air, and an expansion valve 123. , are connected by the refrigerant pipe 118 . The outdoor heat exchanger 117 is provided with an outdoor fan 167 for passing outside air through the outdoor heat exchanger 117 .

Here, in the refrigerant circulation circuits 30 and 130, R32 refrigerant, for example, is used as a refrigerant to constitute a heat pump cycle. Note that the refrigerant may be an HFC refrigerant, an HFO refrigerant, or a carbon dioxide refrigerant. In the refrigerant pipe 18, the pipe portion 18a is provided with a discharge temperature sensor 20 for detecting the refrigerant discharge temperature Tout discharged from the compressor 14. A suction temperature sensor 32 is provided for detecting a refrigerant suction temperature Tin of the refrigerant. The outdoor heat exchanger 17 is provided with an outside air temperature sensor 22 for detecting the outside air temperature Tair. The detection results of these sensors 20, 32, 22 are input to the outdoor unit controller 410 provided in the outdoor unit 300, and further to the hot water storage controller 420 provided in the hot water storage unit 100 and the indoor unit 200 as appropriate. It is also input to the indoor unit control unit 430 provided, the heat exchange control unit 440 provided in the heat exchange unit 400, and the heat pump control unit 450 provided in the heat pump unit 500 (it may be received via the outdoor unit control unit 410 and may be received directly from the sensors 20, 32, 22).

Further, in the refrigerant pipe 25 of the heat exchange unit 400, the refrigerant outflow temperature T2 (third detection value) flowing out from the refrigerant-side flow path 15b toward the expansion valve 111 is detected in the pipe portion 25b. An outflow temperature sensor 21 is provided. The water-refrigerant heat exchanger 15 is provided with a condensation temperature sensor 33 for detecting the refrigerant condensation temperature when the refrigerant is condensed in the refrigerant-side passage 15b. The detection results of these sensors 21 and 33 are input to the heat exchange control section 440 provided in the heat exchange unit 400, and further appropriately the outdoor unit control section 410, the indoor unit control section 430, and the hot water storage control section. 420 and the heat pump control unit 450 (it may be received via the heat exchange control unit 440 or may be received directly from the sensors 21 and 33).

Further, in the refrigerant pipe 26 of the indoor unit 200, the indoor heat exchanger 27 is provided with an indoor temperature sensor 34 for detecting the indoor temperature Tr of the air-conditioned space. The detection result of the sensor 34 is input to the indoor unit control unit 430 provided in the indoor unit 200, and furthermore, the outdoor unit control unit 410, the hot water storage control unit 420, the heat exchange control unit 440, and the heat pump are input as appropriate. It is also input to the control unit 450 (it may be received via the indoor unit control unit 430 or may be received directly from the sensor 34).

The hot water storage controller 420 of the hot water storage unit 100, the heat exchange controller 440 of the heat exchange unit 400, the outdoor unit controller 410 of the outdoor unit 300, and the indoor unit controller of the indoor unit 200 430 and the heat pump controller 450 of the heat pump unit 500 are connected to each other so as to be able to communicate with each other, and based on the detection results of the sensors, operate the hot water storage unit 100 and the heat exchange unit 400 in cooperation with each other. , the operation of each device/actuator in the outdoor unit 300 , the indoor unit 200 , and the heat pump unit 500 .

At this time, the indoor unit 200 can be operated by an appropriate operating section 60 such as a remote controller (hereinafter simply referred to as "remote controller 60"). That is, the remote controller 60 is connected to, for example, the indoor unit control unit 430 so that information can be transmitted and received. , atmospheric exhaust heat cooling operation (hereinafter referred to as “normal cooling operation” as appropriate), exhaust heat hot water supply cooling operation (hereinafter referred to as “exhaust heat hot water supply operation” as appropriate), hot water storage tank only by the heat pump unit 500 2 (hereinafter referred to simply as "boiling operation"), or the like. The instruction contents from these remote controllers 60 are input to the indoor unit control section 430 provided in the indoor unit 200, and furthermore, the outdoor unit control section 410, the heat exchange control section 440, and the hot water storage control section 420 are appropriately controlled. and the heat pump control unit 450 (may be received via the indoor unit control unit 430 or may be received directly from the remote controller 60).

Next, the outdoor unit controller 410 provided in the outdoor unit 300 will be described. Although not shown in detail, the outdoor unit control unit 410 includes a storage unit that stores various data and programs, and a control unit that performs arithmetic and control processing. A functional configuration of the outdoor unit control section 410 will be described with reference to FIG.

As shown in FIG. 2, the outdoor unit control section 410 includes a four-way valve control section 410A, a compressor control section 410B, an expansion valve control section 410C, an outdoor fan control section 410D, and a two-way valve control section 410E. , are functionally provided.

The four-way valve control unit 410A receives an operation instruction from the remote controller 60 indicating which operation should be performed and the stored hot water temperature detected by the stored hot water temperature sensor 12 .

The four-way valve control unit 410A actually controls the heat pump water heater 1 in what kind of operation mode (the above-mentioned normal cooling operation , hot water supply operation using exhaust heat, boiling operation), and the corresponding operation information is sent to the compressor control unit 410B, the expansion valve control unit 410C, the outdoor fan control unit 410D, and the two-way valve control unit 410E. , and to the hot water storage controller 420 , the indoor unit controller 430 , the heat exchange controller 440 , and the heat pump controller 450 . In addition, the four-way valve control unit 410A outputs an open/close signal corresponding to the determined operation mode to the four-way valve 31 to switch the four-way valve 31 (details of control will be described later).

The outside air temperature Tair detected by the outside air temperature sensor 22, the indoor temperature Tr detected by the indoor temperature sensor 34, and the air conditioner set temperature Tcon set by the remote controller 60 are stored in the compressor control unit 410B. is input (in addition to direct input, the above-mentioned indirect input is also included. The same applies hereinafter). The compressor control unit 410B controls the rotation of the compressor 14 based on at least one of the input temperature and setting according to the operation information input from the four-way valve control unit 410A as described above. control the numbers. Note that the rotational speed (control value) of the compressor 14 at this time is also output to an expansion valve control section 440B of the heat exchange control section 440 described later (not shown).

The expansion valve control unit 410C stores the refrigerant discharge temperature Tout detected by the discharge temperature sensor 20, the refrigerant outflow temperature T2 detected by the outflow temperature sensor 21, and the refrigerant outflow temperature T2 detected by the intake temperature sensor 32. Refrigerant intake temperature Tin is input. The expansion valve control unit 410C controls the degree of opening of the expansion valve 113 based on at least one of the input temperatures according to the operation information from the four-way valve control unit 410A (detailed control). content will be described later).

The two-way valve control section 410E controls opening and closing of the two-way valve 122 according to the operation information from the four-way valve control section 410A (details of the control will be described later).

The outdoor air temperature Tair detected by the outdoor air temperature sensor 22 is input to the outdoor fan control unit 410D. The outdoor fan controller 410D controls the rotation speed of the outdoor fan 67 based on the outside air temperature Tair in accordance with the operation information from the four-way valve controller 410A.

The operation mode may be determined by the hot water storage controller 420 , the indoor unit controller 430 , the heat exchange controller 440 , or the heat pump controller 450 . In this case, the operation information corresponding to the determined operation mode is input to the outdoor unit control unit 410 from the hot water storage control unit 420, the indoor unit control unit 430, the heat exchange control unit 440, and the heat pump control unit 450. The four-way valve control section 410A, the compressor control section 410B, the expansion valve control section 410C, the outdoor fan control section 410D, and the two-way valve control section 410E perform various controls according to the input operation information.

Next, the heat exchange control section 440 provided in the heat exchange unit 400 will be described. The heat exchange control section 440 includes a storage section and a control section, similarly to the outdoor unit control section 410, and its functional configuration will be described with reference to FIG.

As shown in FIG. 3, the heat exchange control section 440 functionally includes a pump control section 440A, an expansion valve control section 440B, and a two-way valve control section 440C.

The pump control unit 440A receives the operation information from the outdoor unit control unit 410, the boiling temperature Tb detected by the boiling temperature sensor 24, the pump flow rate detected by the flow rate sensor 28, is entered. The pump control unit 440A controls the rotation speed of the boiling pump 19 based on the input boiling temperature Tb in accordance with the operation information input from the outdoor unit control unit 410 as described above. In the present embodiment, the pump control unit 440A always adjusts the above boiling temperature according to the deviation between the boiling temperature Tb and a predetermined target boiling temperature Tbo (see FIG. The rotation speed of the boiling pump 19 is controlled.

The expansion valve control unit 440B receives the operation information from the outdoor unit control unit 410, the outside air temperature Tair detected by the outside air temperature sensor 22, and the compressor control unit 410B of the outdoor unit control unit 410. The input rotation speed of the compressor 14 (control value. However, the actual rotation speed of the compressor 14 detected by a known method may be input) and the refrigerant detected by the outflow temperature sensor 21 The outflow temperature T2, the refrigerant suction temperature Tin detected by the suction temperature sensor 32, and the refrigerant discharge temperature Tout detected by the discharge temperature sensor 20 are input. The expansion valve control section 440B controls the opening/closing and the degree of opening of the expansion valve 1110 based on at least one of the input temperature and rotation speed in accordance with the operation information from the outdoor unit control section 410. do.

The operation information from the outdoor unit control unit 410 is input to the two-way valve control unit 440C. The two-way valve control unit 440C controls the opening/closing operation of the two-way valve 121 based on the operation information (details of control will be described later).

Note that, similarly to the above, the operation mode may be determined in the heat exchange control section 440 (for example, the two-way valve control section 440C), the indoor unit control section 430, the hot water storage control section 420, or the heat pump control section 450. In this case, the pump control unit 440A, the expansion valve control unit 440A, and the expansion valve control unit 440A according to the operation information corresponding to the operation mode determined by the two-way valve control unit 440C, the indoor unit control unit 430, the hot water storage control unit 420, and the heat pump control unit 450. 440B performs various controls.

Next, the indoor unit controller 430 provided in the indoor unit 200 will be described. The indoor unit control unit 430 includes a storage unit and a control unit, similarly to the outdoor unit control unit 410 and the heat exchange control unit 440, and the functional configuration thereof will be described with reference to FIG.

As shown in FIG. 4, the indoor unit controller 430 functionally includes an indoor fan controller 430A. The indoor fan controller 430A receives the operation information from the outdoor unit controller 410, the indoor temperature Tr detected by the indoor temperature sensor 34, and the air conditioner set temperature Tcon set by the remote controller 60. is entered. 430 A of indoor fan control parts control the rotation speed of the said indoor fan 77 based on the said indoor temperature Tr and the air-conditioner preset temperature Tcon according to the said operation information from the said outdoor unit control part 410. FIG.

It should be noted that the operation mode may be determined in the indoor unit control unit 430, the heat exchange control unit 440, the hot water storage control unit 420, or the heat pump control unit 450, as described above. In this case, the indoor fan control unit 430A performs the control according to the operation information corresponding to the operation mode determined by the indoor unit control unit 430, the heat exchange control unit 440, the hot water storage control unit 420, and the heat pump control unit 450. .

Next, the hot water storage controller 420 provided in the hot water storage unit 100 will be described. Like the outdoor unit control unit 410, the heat exchange control unit 440, and the indoor unit control unit 430, the hot water storage control unit 420 includes a storage unit and a control unit, and its functional configuration will be described with reference to FIG.

As shown in FIG. 5, the hot water storage controller 420 functionally includes a return controller 420B and a temperature controller 420C.

The return control unit 420B receives the operation information from the outdoor unit control unit 410, the stored hot water temperature detected by the stored hot water temperature sensor 12, and the boiling temperature Tb detected by the boiling temperature sensor 24. , is entered. The return control unit 420B appropriately controls the opening degrees of the three-way valves 10C and 10D in accordance with the operation information from the outdoor unit control unit 410 and the heating status of the hot water (hot water storage status) corresponding to the hot water storage temperature. do. As a result, whether the hot water to the hot water storage tank 2 is returned to the lower portion of the hot water storage tank 2 via the pipes 6c and 6e, or to the middle portion of the hot water storage tank 2 via the pipes 6c and 6d, or the pipe 6b It is controlled whether the hot water is returned to the upper part of the hot water storage tank 2 via . In the present embodiment, basically, during the exhaust heat utilization hot water supply operation, hot water (intermediate hot water) after heat exchange in the water-refrigerant heat exchanger 15 is supplied to the hot water storage tank 2 via the pipes 6c and 6d. During the boiling operation, the hot water (high temperature water) heated by the heat pump unit 500 is returned to the upper portion of the hot water storage tank 2 through the pipe 6b.

The operation information from the outdoor unit control unit 410, the stored hot water temperature detected by the stored hot water temperature sensor 12, and the hot water supply temperature detected by the hot water supply temperature sensor 37 are input to the temperature control unit 420C. . The temperature control unit 420C determines whether the temperature of the hot water supplied from the hot water supply temperature sensor 37 is adjusted according to the operation information from the outdoor unit control unit 410 and the heating status (storage status) of the hot water corresponding to the stored hot water temperature. , the opening degrees of the mixing valves 10A and 10B are appropriately controlled so as to achieve the hot water supply set temperature.

Note that the operation mode may be determined in the hot water storage control unit 420, the heat exchange control unit 440, the indoor unit control unit 430, or the heat pump control unit 450, as described above. In this case, the return control section 420B and the temperature control section 420C perform the above control according to the operation information corresponding to the operation mode determined by the hot water storage control section 420, the heat exchange control section 440 and the indoor unit control section 430.

Next, the heat pump control section 450 provided in the heat pump unit 500 will be described. The heat pump control unit 450 includes a storage unit and a control unit, similarly to the outdoor unit control unit 410, the heat exchange control unit 440, the indoor unit control unit 430, and the hot water storage control unit 420. The functional configuration of the heat pump control unit 450 is shown in FIG. will be explained.

As shown in FIG. 6, the heat pump control section 450 functionally includes a pump control section 450A, a compressor control section 450B, an expansion valve control section 450C, and an outdoor fan control section 450D.

The pump control unit 450A receives the operation information from the outdoor unit control unit 410 and the temperature sensor (not shown) provided on the outlet side of the water-side flow path 115a of the water-refrigerant heat exchanger 115. and outlet temperature are entered. The pump control unit 450A controls the rotation speed of the boiling pump 119 based on at least one of the input temperature and setting according to the operation information input as described above.

The operating information from the outdoor unit control unit 410 and the outside air temperature Tair detected by the outside air temperature sensor 22 are input to the compressor control unit 450B. The compressor control unit 450B controls the rotation speed of the compressor 114 based on at least one of the input temperature and setting according to the operation information input as described above.

The expansion valve control unit 450C receives the operating information from the outdoor unit control unit 410 and the refrigerant discharge temperature detected by a discharge temperature sensor 20 (not shown) provided on the discharge side of the compressor 114. is entered. The expansion valve control unit 450C controls the degree of opening of the expansion valve 123 based on at least one of the input temperatures according to the operating information.

The operating information from the outdoor unit control section 410 and the outdoor air temperature Tair detected by the outdoor air temperature sensor 22 are input to the outdoor fan control section 450D. The outdoor fan control unit 450D controls the rotation speed of the outdoor fan 167 based on the outside air temperature Tair according to the operation information.

Note that, similarly to the above, the operation mode may be determined in the heat pump control unit 450, the hot water storage control unit 420, the indoor unit control unit 430, or the heat exchange control unit 440. In this case, according to the operation information corresponding to the operation mode determined by the heat pump control unit 450, the hot water storage control unit 420, the indoor unit control unit 430, and the heat exchange control unit 440, the compressor control unit 450B, the expansion valve control The control is performed by the section 450C and the outdoor fan control section 450D.

The heat pump control unit 450 controls the compressor control unit 450B, the expansion valve control unit 450C, and the outdoor fan control unit 450D even when the heat exchange in the water-refrigerant heat exchanger 15 is not performed (or Together with the execution of the heat exchange in the water-refrigerant heat exchanger 15, the boiling-up operation and the like for heating and supplying the hot water in the hot water storage tank 2 can be executed.

Here, as described above, the heat pump water heater 1 of the present embodiment can selectively execute various types of operations such as the normal cooling operation, the hot water supply operation using exhaust heat, and the boiling operation. Details of each operation will be described below.

<Normal cooling operation>
First, normal cooling operation will be described with reference to FIG. During the normal cooling operation (corresponding to the air exhaust heat cooling mode) shown in FIG. It is switched to the position (the above-described cooling side) in which the portion 18c is communicated with the pipe portion 18b. The two-way valve control units 410E and 440C switch the two-way valve 122 to the open state and the two-way valve 121 to the closed state. Furthermore, the expansion valve control units 410C and 440B control the expansion valve 113 to be adjusted to an appropriate degree of opening and the expansion valve 111 to be fully closed.

As a result, the piping section 18a on the discharge side of the compressor 14→piping section 18d→piping section 18e (two-way valve 122)→outdoor heat exchanger 17→piping section 18f (expansion valve 113)→piping section 26b→indoor heat exchange Refrigerant path of vessel 27→piping portion 26a→piping portion 18b→piping portion 18c on the suction side of compressor 14 is formed.

As a result, the gaseous refrigerant sucked at low temperature and low pressure is compressed by the compressor 14 to become high temperature and high pressure gas, and then the outdoor heat exchanger functions as a condenser as the outdoor fan 67 rotates. At 17, it changes into a high-pressure liquid while exchanging heat with the outside air and releasing heat. The refrigerant thus liquefied is appropriately decompressed by the expansion valve 113 to become a low-temperature, low-pressure liquid, and is in a state where it is easy to evaporate. It absorbs heat from the indoor air, evaporates, and changes to gas, thereby cooling the air-conditioned space, and returns to the compressor 14 again as a low-temperature, low-pressure gas.

<Exhaust heat utilization hot water supply operation>
Next, the exhaust heat utilization hot water supply operation will be described with reference to FIG. During the hot water supply operation using exhaust heat (corresponding to the cooling mode using exhaust heat) shown in FIG. be done. The two-way valve control units 410E and 440C switch the two-way valve 122 to the closed state and the two-way valve 121 to the open state. Further, the expansion valve control units 410C and 440B control the expansion valve 113 to be fully closed and the expansion valve 111 to be adjusted to an appropriate opening.

As a result, the piping portion 18a on the discharge side of the compressor 14 → the piping portion 18d → the piping portion 25a (the two-way valve 121) → the water refrigerant heat exchanger 15 → the piping portion 25b (the expansion valve 111) → the piping portion 26b → the indoor heat A refrigerant path of the exchanger 27→the pipe portion 26a→the pipe portion 18b→the pipe portion 18c on the suction side of the compressor 14 is formed.

As a result, after the gaseous refrigerant sucked at low temperature and low pressure is compressed by the compressor 14 to become a high temperature and high pressure gas, the refrigerant side of the water-refrigerant heat exchanger 15 functioning as a condenser It changes into a high-pressure liquid while releasing heat in the flow path 15b. The refrigerant thus liquefied is appropriately decompressed by the expansion valve 111 to become a low-temperature, low-pressure liquid and is in a state where it is easy to evaporate. It absorbs heat from the indoor air, evaporates, and changes to gas, thereby cooling the air-conditioned space, and returns to the compressor 14 again as a low-temperature, low-pressure gas.

Further, the boiling pump 19 is rotated under the control of the pump control section 440A, so that the low-temperature water (unheated water) taken out from the pipe 5b connected to the lower part of the hot water storage tank 2 is transferred to the heat exchange unit 400. After receiving heat from the condensing refrigerant in the water-side passage 15a of the water-refrigerant heat exchanger 15 and heating it to become the middle-temperature water, it is returned to the hot water storage tank 2 (hot water supply process). That is, the heat exchange unit 400 functions as a medium-temperature heat source for storing medium-temperature water in the hot water storage tank 2 . As a result of the above, it is possible to utilize the cooling exhaust heat in summer for heating (supplying) hot water to the hot water storage tank 2 .

As described in the above operation mode, in the present embodiment, the four-way valve 31, the two-way valves 122 and 121, the expansion valves 113 and 111, and the outdoor unit control section for controlling these 410, the hot water storage control unit 420, the indoor unit control unit 430, and the heat exchange control unit 440 function as mode switching means described in each claim.

<Boiling operation>
Next, boiling operation will be described with reference to FIG. During the boiling-up operation shown in FIG. 9, the expansion valve control section 450C controls the expansion valve 123 to be adjusted to an appropriate opening degree.

As a result, a refrigerant path of the discharge side of the compressor 114→flow path 115b on the refrigerant side of the water refrigerant heat exchanger 115→refrigerant pipe 118 (expansion valve 123)→outdoor heat exchanger 117→compressor 114 is formed. .

As a result, after the gaseous refrigerant sucked at low temperature and low pressure is compressed by the compressor 114 to become a high temperature and high pressure gas, the refrigerant side flow of the water refrigerant heat exchanger 115 functioning as a condenser In the passage 115b, heat is exchanged with the water flowing through the passage 115a on the water side, heat is released to the water, and the water changes into a high-pressure liquid while being heated. The refrigerant thus liquefied is decompressed by the expansion valve 123 to become a low-temperature, low-pressure liquid and is in a state where it is easy to evaporate. It absorbs heat by changing to a gas at the bottom, and returns to the compressor 114 again as a low-temperature, low-pressure gas.

In addition, by rotating the boiling pump 119 under the control of the pump control section 450A, the low-temperature water (unheated water) taken out from the heating pipe 5 connected to the lower part of the hot water storage tank 2 is transferred to the heat pump unit 500. In the water-side flow path 115a of the water-refrigerant heat exchanger 115, heat is received from the condensed refrigerant and heated to a high temperature of about 65 ° C. to 90 ° C., which is easy to use as a heat source on the heat utilization side such as reheating the bath. After that, the high-temperature water (heated water) is sequentially stored in the hot water tank 2 in a layered manner by being returned into the hot water tank 2 through the heating return pipe 6 connected to the top of the hot water tank 2 . That is, the heat pump unit 500 functions as a high temperature heat source for storing the high temperature water in the hot water storage tank 2 .

<Features of Embodiment>
The feature of this embodiment having the above configuration and basic operation is that the target boiling temperature Tbo is temporarily corrected to increase when the cooling output is increased during the hot water supply operation using exhaust heat. The details will be explained step by step.

<Feedback control of pump speed>
As described above, the rotation speed of the boiling pump 19 that circulates hot water in the heating circulation circuit 4 is controlled by the pump control unit 440A to match the boiling temperature Tb of the hot water detected by the boiling temperature sensor 24 and the target value. Feedback control is performed so that the boiling temperature Tb reaches the target boiling temperature Tbo in accordance with the deviation from the boiling temperature Tbo. As a result, for example, when the output (cooling output) of the refrigeration cycle increases, the rotation speed of the boiling pump 19 increases to maintain the boiling temperature Tb at the target boiling temperature Tbo, and the flow rate of hot water increases. As a result, the output (boiling output) in the heating circulation circuit 4 increases. Conversely, when the cooling output decreases, the rotation speed of the boiling pump 19 decreases in order to maintain the boiling temperature Tb, and the boiling output also decreases.

<Return medium-temperature water to the hot water storage tank>
At this time, the hot water from the water-side flow path a of the water-refrigerant heat exchanger 15 is returned to the middle portion in the height direction of the hot water storage tank 2 via the above-described pipes 6d and 8d. This has the following significance. That is, since the boiling output increases or decreases according to the magnitude of the cooling output as described above, the target boiling temperature Tbo is usually relatively low (for example, 45 ° C., etc., which will be the above-described medium temperature) is set. At this time, the upper part of the hot water storage tank 2 stores hot water (high-temperature water described above) which is heated by the above-described boiling operation and has a temperature higher than the above-mentioned temperature. Therefore, as described above, the hot water storage tank 2 can be used, for example, for reheating the bath by returning the medium-temperature water having a relatively low temperature not to the upper portion of the hot water storage tank 2 but to the middle portion in the height direction of the hot water storage tank 2. It is possible to prevent the high-temperature water layer in the inner upper part from being broken.

Here, since the boiling output increases and decreases in conjunction with the cooling output as described above, when the cooling output increases to a certain extent, the boiling output also increases and the flow rate of the intermediate water increases. . As a result, the medium-temperature water is returned into the hot water tank 2 at a relatively high speed, destroying the boundary layer between the upper high-temperature water layer and the intermediate medium-temperature water layer in the hot water storage tank 2. There is a risk that it will be lost.

<Correction of target boiling temperature>
Therefore, in the present embodiment, the pump control section 440A corrects the increase of the target boiling temperature Tbo in order to prevent the boundary layer from breaking. Details of this process will be described with reference to FIGS. FIG. 10(a) shows the temporal behavior of the target boiling temperature Tbo set by the pump control unit 440A after the exhaust heat utilization hot water supply operation is started, and FIG. 10(b) shows the target boiling temperature Tbo. An example of the temporal behavior of the boiling-up temperature Tb corresponding to the setting of the upper temperature Tbo is shown, and FIG. An example of temporal behavior of the output, the cooling output, and the pump flow rate is shown.

In FIGS. 10(a) to 10(c), first, after the exhaust heat utilization hot water supply operation is started, the cooling output gradually increases, and the boiling output gradually increases accordingly. Corresponding to this, the rotation speed of the boiling pump 19 is controlled to gradually increase under the control of the pump control section 440A, thereby increasing the pump flow rate. Thereby, the boiling-up temperature Tb detected by the boiling-up temperature sensor 24 is maintained at the target boiling-up temperature Tbo (45° C. in this example) at this time (that is, before the increase correction described later is performed). controlled to be This increase control is continued until the pump flow rate reaches a predetermined flow rate (4 liters/min in the example of FIG. 10(c)) (section L1) (rotational speed increase processing).

At this time, if the pump control unit 440A maintains the target boiling temperature Tbo at 45° C., the further increase in the cooling output and the boiling output causes the pump flow rate to rise beyond the predetermined flow rate. (see B indicated by the two-dot chain line). As a result, the boundary layer between the high-temperature water and the medium-temperature water may be destroyed due to the increased flow velocity of the medium-temperature water returning to the hot water storage tank 2 as described above. Therefore, in this embodiment, after the pump flow rate reaches the predetermined flow rate (4 liters/min in this example), the pump control section 440A sets the target boiling temperature Tbo to a predetermined value ΔT (for example, In the example shown in (a), the correction is increased by 3°C). As a result, the boiling-up temperature Tb is allowed to rise to the increased value of the target boiling-up temperature Tbo (48° C. in this example) (see A in FIG. 10(b)). , until the boiling temperature Tb increases to 48° C. (section L2), the pump flow rate is kept substantially constant, that is, at the predetermined flow rate (section L2 as the first processing period).

Thereafter, in this example, the cooling output and the boiling output become substantially constant values at the timing when the boiling temperature Tb becomes the corrected target boiling temperature Tbo (48° C. in the above example). As a result, under the control of the pump control unit 440A, the pump flow rate is kept substantially constant for a while (section L3 as the second processing period) while the boiling temperature Tb=the post-correction target boiling temperature Tbo. drip.

After that, a certain amount of time passes (for example, the cooling load decreases), and the cooling output and the boiling output decrease. Boiling temperature Tb gradually decreases (section L4 as the third processing period).

Then, in this example, when the detected boiling-up temperature Tb drops to the target boiling-up temperature Tbo (45° C. in this example) before performing the increase correction, the pump control unit 440A controls As the target boiling temperature Tbo returns to the value before the increase correction, the rotational speed of the boiling pump 19 is controlled to gradually decrease, thereby decreasing the pump flow rate. As a result, the detected boiling temperature Tb is controlled so as to become the target boiling temperature Tbo after the recovery (rotational speed reduction process executed in section L5).

Note that the processing executed in the sections L2, L3, and L4 corresponds to the flow constant processing.

As described above, in the present embodiment, during the hot water supply operation using exhaust heat, even if the cooling output further increases after the pump flow rate reaches the predetermined flow rate, the boiling output correspondingly increases. The pump flow rate can be kept constant at the predetermined flow rate by absorbing the amount by increasing the boiling-up temperature Tb.

<Processing procedure>
In order to realize the above method, the processing procedure executed by the outdoor unit control unit 410, the hot water storage control unit 420, the indoor unit control unit 430, the heat exchange control unit 440, and the heat pump control unit 450 is shown in the flowchart of FIG. explained by

In FIG. 11, first, in step S10, for example, the outdoor unit control unit 410 determines whether or not an instruction to start the exhaust heat utilization hot water supply operation has been given by an appropriate operation on the remote controller 60 or not. If the command to start driving is not given, this determination is not satisfied (S110: NO), and the loop waits until this determination is satisfied. If the start is instructed, this determination is satisfied (S10: YES), and the process proceeds to step S20.

In step S20, for example, the pump control section 440A of the heat exchange control section 440 initializes a flag F indicating whether or not the target boiling temperature Tbo is to be corrected to increase to F=0.

After that, in step S30, the outdoor unit control unit 410, the hot water storage control unit 420, the indoor unit control unit 430, and the heat exchange control unit 440 cooperate with each other to start the hot water supply operation using exhaust heat. As a result, as shown in FIG. 8, hot water after heat exchange in the water-refrigerant heat exchanger 15 is returned to the middle portion in the height direction of the hot water storage tank 2 via the pipes 6c, 6d, and 8d. .

Then, in step S40, for example, the pump control section 440A determines whether the flag F is 1 or not. As described above, immediately after the start of the hot water supply operation using exhaust heat, the flag F remains at 0, so the determination is not satisfied (S40: NO), and the process proceeds to step S50.

In step S50, the pump control unit 440A determines whether or not the pump flow rate has increased to the predetermined flow rate (4 liters per minute in the example of FIG. 10) based on the detection result of the flow rate sensor 28 described above. Immediately after the exhaust heat utilization hot water supply operation is started, the pump flow rate has not yet increased sufficiently and this determination is not satisfied (S50: NO), and the process proceeds to step S120.

In step S120, the pump control section 440A controls the rotation speed of the boiling pump 19 so that the boiling temperature Tb detected by the boiling temperature sensor 24 becomes the target boiling temperature Tbo at this time. After that, the process returns to step S40 and repeats the same procedure. As a result, step S40→step S50→step S120→step S40→ . . . are repeated until the pump flow rate reaches the predetermined flow rate. increases while being controlled to match the target boiling temperature Tbo, and the pump flow rate gradually increases.

Then, when the pump flow rate reaches the predetermined flow rate in the above repetition, the determination in step S50 is satisfied (S50: YES), and the process proceeds to step S60.

In step S60, the pump control unit 440A performs an increase correction by adding a predetermined value ΔT (3° C. in the example above) to the target boiling temperature Tbo (45° C. in the example above) at this time.

After that, in step S70, the pump control section 440A controls the rotation speed of the boiling pump 19 (fixes it at a constant value) so as to keep the pump flow rate constant. Then, in step S80, the pump control section 440A sets the flag F to F=1 indicating that the target boiling temperature Tbo has been corrected to increase, and returns to step S40.

In the step S40 returned in this way, since F=1 in the step S80, the determination is satisfied (S40: YES), and the process proceeds to step S90.

In step S90, the pump control unit 440A controls the boiling temperature Tb detected by the boiling temperature sensor 24 to be the predetermined value ΔT from the target boiling temperature Tbo at this time (that is, after the correction for increase). , that is, whether or not it has decreased to the target boiling temperature Tbo before the increase correction. As described above in the example of the section L4 in FIG. 10, the cooling output and the boiling output are lowered so that the boiling temperature Tb reaches the target boiling temperature Tbo (45° C. in the above example) before the increase correction. The determination in step S90 is not satisfied (S90: NO) until the temperature drops, and the loop waits.

In step S100, the pump control unit 440A changes the target boiling temperature Tbo at this time (that is, the target boiling temperature Tbo after the increase correction; 48° C. in the above example) to the predetermined value ΔT (the above example 3°C) to return to the value before correction. Then, in step S110, the pump control unit 440A sets the flag F to F=0 corresponding to the return to the state before the increase correction, returns to step S40, and repeats the same procedure thereafter.

In the above, the pump control unit 440A that executes steps S40, S50, S120, S60, S70, S80, S90, S100, and S110 of the flow of FIG. 11, and the flow rate sensor 28 ( or the rotational speed sensor) functions as the pump control means described in each claim.

Even if it is determined in step S50 that the pump flow rate has increased to the predetermined flow rate, if the stored hot water temperature sensor 12 detects that there is no high-temperature water in the hot water storage tank 2, steps S60 to S80 are performed. It is also possible to proceed to step 120 without executing .

<Effects of Embodiment>
As described above, in the present embodiment, during the hot water supply operation using exhaust heat, even if the cooling output further increases after the pump flow rate reaches the predetermined flow rate, the boiling output correspondingly increases. The pump flow rate can be kept constant at the predetermined flow rate by absorbing the amount by increasing the boiling-up temperature Tb. As a result, a certain upper limit can be set for the speed of medium-temperature water returning into the hot water storage tank 2 via the pipes 6d and 8d. The boundary layer between can be prevented from being destroyed.

Further, particularly in the present embodiment, for example, by appropriately setting the value of the corrected target boiling-up temperature Tbo (in other words, by appropriately setting the value of the predetermined value ΔT), the pump control unit 440A can be controlled. Thus, during the period (the section L2) in which the boiling temperature Tb increases due to the increase in the cooling output, the cooling output stops increasing and becomes constant, and the boiling temperature Tb reaches the target boiling temperature Tbo. (section L3), and then the period (section L4) in which the boiling temperature Tb decreases as the cooling output decreases. can be kept constant.

Further, particularly in the present embodiment, when the boiling-up temperature Tb has decreased to the target boiling-up temperature Tbo (45° C. in the above example) before the increase correction, the pump control unit 440A returns to the original control. While decreasing the rotational speed of the upper pump 19, the boiling temperature Tb is controlled to become the original (before correction) target boiling temperature Tbo. As a result, the cooling COP, which has decreased due to the increase correction of the target boiling-up temperature Tbo, can be returned to the original desired high level.

Further, particularly in this embodiment, the pump flow rate is determined by the flow rate sensor 28 (or the rotation speed sensor), and the above-described processing is performed by the pump control section 440A based on the pump flow rate. As a result, the pump flow rate can be reliably kept constant after the target boiling temperature Tbo is corrected to increase.

Further, particularly in this embodiment, based on the detection result of the flow rate sensor 28 or the detection result of the rotation speed sensor, the control for increasing the rotation speed of the pump and the control for stabilizing the flow rate are accurately performed. be able to.

In addition, particularly in this embodiment, the cooling operation can be performed in two modes (an atmospheric exhaust heat cooling mode in the normal cooling operation, and an exhaust heat utilization cooling mode in the exhaust heat utilization hot water supply operation). During the exhaust heat utilization hot water supply operation, a refrigeration cycle is realized in the route of compressor 14 discharge side→water-refrigerant heat exchanger 15→indoor heat exchanger 27→compressor 14 suction side as described above. On the other hand, during the normal cooling operation, the indoor heat exchanger 27 communicates with the discharge side of the compressor 14 at the inlet side of the outdoor heat exchanger 17 and communicates with the suction side of the compressor 14 at the outlet side. The outlet side of the outdoor heat exchanger 17 communicates with the inlet side of . In this case, the high-temperature and high-pressure refrigerant gas discharged from the compressor 14 releases heat to the outside air in the outdoor heat exchanger 17 (functioning as a condenser) and condenses to become a liquid refrigerant, and then in the indoor heat exchanger 27 (functioning as an evaporator). ), the heat is absorbed from the indoor air and returned to the compressor 14, thereby realizing a normal cooling operation.

In addition, instead of setting the upper limit of the pump flow rate of the boiling pump 19 by the control of the pump control section 440A in the sections L2, L3, and L4 in FIG. The pump flow rate may be limited to the predetermined flow rate by providing a valve (corresponding to flow rate limiting means in this case). In this case, even if the pump control unit 440A does not correct the target boiling temperature Tbo as described above (that is, even if the target boiling temperature Tbo remains fixed), the flow rate limiting function of the constant flow valve is used to , the rotation speed increasing process corresponding to the section L1 and the flow rate stabilization process corresponding to the sections L2, L3, and L4 can be performed.

That is, in the rotation speed increasing process, the pump control unit 440A is kept in the The number of revolutions of the circulation pump 19 is increased, and in the flow rate stabilization process, the pump flow rate is controlled to be kept constant by the function of the constant flow rate valve.

In this case, the pump control unit 440A, which corresponds to step S120 in FIG. functions as the pump control means described in each claim.

In this modification, the flow rate of the pump can be reliably kept constant. It is possible to prevent the boundary layer in the from being destroyed. Moreover, in this modification, in particular, by using the constant flow discharge function of the constant flow valve, the rotational speed increasing process and the flow constant process can be performed with high reliability and accuracy.

The present invention is not limited to the above embodiments, and can be applied without changing the gist of the invention. can be replaced with Also, instead of the expansion valves 111 and 113, an ejector may be used as a decompressor.

Further, in the above-described embodiment, the heat pump unit 500 is used as an example of the heat pump unit 500 as a high-temperature heat source for boiling hot water at a temperature higher than the boiling temperature in the hot water supply operation using exhaust heat. It is not limited to this. That is, for example, an electric heater may be arranged in the hot water storage tank 2 and hot water may be boiled into the hot water storage tank 2 by the electric heater. Also in this case, the same effect as described above is obtained.

1 Heat pump water heater (cooling exhaust heat hot water storage device)
2 hot water storage tank 6d piping (return pipe)
REFERENCE SIGNS LIST 12 hot water storage temperature sensor 14 compressor 15 water-refrigerant heat exchanger 15a refrigerant-side flow path 15b water-side flow path 17 outdoor heat exchanger (heat pump heat exchanger)
19 boiling pump (circulation pump)
24 boiling temperature sensor (boiling temperature detection means)
27 indoor heat exchanger 28 flow rate sensor (flow rate determining means)
30 refrigerant circulation circuit 104 heating circulation circuit (hot water circulation circuit)
105a piping (hot water piping)
106a piping (hot water piping)
410B Compressor control unit 440 Heat exchange control unit 440A Pump control unit Tb Boiling temperature (actual boiling temperature)
Tbo Target boiling temperature

Claims (8)

a water-refrigerant heat exchanger functioning as a condenser that exchanges heat between the refrigerant and water;
an indoor heat exchanger functioning as an evaporator that exchanges heat between the refrigerant and indoor air;
a compressor connected to the water-refrigerant heat exchanger and the indoor heat exchanger;
a hot water storage tank for storing hot water;
has
forming a hot water circulation circuit by annularly connecting the water side of the water-refrigerant heat exchanger and the hot water storage tank with a hot water pipe;
connecting the refrigerant side of the water-refrigerant heat exchanger, the compressor, and the indoor heat exchanger with refrigerant pipes to form a refrigerant circulation circuit;
With respect to the inlet side of the indoor heat exchanger, the inlet side of the water-refrigerant heat exchanger communicates with the discharge side of the compressor, and the outlet side communicates with the suction side of the compressor. In a cooling exhaust heat hot water storage device that communicates with the outlet side of the vessel and performs hot water supply processing to supply hot water heated by the water-refrigerant heat exchanger to the hot water storage tank,
boiling temperature detection means for detecting the actual boiling temperature of hot water flowing out from the water side of the water-refrigerant heat exchanger to the hot water pipe;
a circulation pump for circulating the hot water in the hot water pipe;
pump control means for increasing or decreasing the rotation speed of the circulation pump according to the deviation between the actual boiling point temperature detected by the boiling point temperature detecting means and a predetermined target boiling point temperature;
has
The hot water circulation circuit is
A return pipe connected to the middle portion of the hot water storage tank in the vertical direction for returning hot water to the hot water storage tank,
The pump control means is
After the start of the hot water supply process, by increasing the rotation speed of the circulation pump until the pump flow rate of the circulation pump reaches a predetermined flow rate, the actual temperature detected by the boiling temperature detection means is increased. Rotational speed increase processing for controlling the boiling temperature to be the target boiling temperature;
Flow rate stabilization processing for controlling the pump flow rate to be kept substantially constant while increasing and correcting the target boiling temperature after the pump flow rate reaches the predetermined flow rate;
A cooling exhaust heat hot water storage device characterized by executing The flow rate stabilization process is
a first processing period in which the pump flow rate is kept substantially constant while increasing the actual boiling point temperature;
a second processing period in which the pump flow rate is kept substantially constant after the actual boiling-up temperature reaches the corrected target boiling-up temperature in the first processing period;
a third processing period, after the second processing period, in which the pump flow rate is kept substantially constant while the actual boiling point temperature is decreased;
The cooling exhaust heat and hot water storage device according to claim 1, characterized by comprising: The pump control means is
When the actual boiling point temperature decreases in the flow rate stabilization process and reaches the target boiling point temperature before performing the increase correction, the rotation speed of the circulation pump is decreased to detect the boiling point temperature by the boiling point temperature detecting means. 3. The cooling exhaust heat and hot water storage device according to claim 1, wherein a rotational speed reduction process is executed to control the actual boiling temperature to be the target boiling temperature. The pump control means is
Flow rate determination means for determining the actual pump flow rate by the circulation pump,
In the rotation speed increasing process,
increasing the rotation speed of the circulation pump until the pump flow rate determined by the flow rate determining means reaches the predetermined flow rate;
In the flow rate stabilization process,
4. The cooling exhaust heat and hot water storage device according to any one of claims 1 to 3, wherein said pump flow rate determined by said flow rate determination means is controlled to be kept substantially constant . The flow rate determining means is
A rotation speed sensor provided in the circulation pump, or
5. The cooling exhaust heat and hot water storage device according to claim 4, further comprising a flow rate sensor provided in said hot water pipe. The pump control means is
Flow rate limiting means for limiting the upper limit of the actual pump flow rate by the circulating pump to the predetermined flow rate,
In the rotation speed increasing process,
increasing the rotation speed of the circulation pump until the pump flow rate, which is restricted by the flow rate limiting means, reaches the predetermined flow rate;
In the flow rate stabilization process,
4. The cooling exhaust heat and hot water storage device according to any one of claims 1 to 3, wherein the pump flow rate is controlled to be kept substantially constant by the flow rate limiting means. The flow rate limiting means is
7. The cooling exhaust heat and hot water storage device according to claim 6, wherein said hot water pipe is provided with a constant flow valve. a heat pump heat exchanger connected in parallel with the water-refrigerant heat exchanger for the compressor and performing heat exchange between the refrigerant and the outside air;
an air exhaust heat cooling mode in which the inlet side of the heat pump heat exchanger communicates with the discharge side of the compressor and the outlet side of the heat pump heat exchanger communicates with the inlet side of the indoor heat exchanger; The hot water supply process is performed by connecting the inlet side of the water-refrigerant heat exchanger to the discharge side of the machine and the outlet side of the water-refrigerant heat exchanger to the inlet side of the indoor heat exchanger. a mode switching means capable of switching between a cooling mode and
8. The cooling exhaust heat and hot water storage device according to any one of claims 1 to 7, wherein a

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