JP2007271163A - Returned hot water recovering method and hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply system capable of improving operation efficiency of a heat pump unit in heating up of a tank without lowering high-temperature hot water supply performance. <P>SOLUTION: In this hot water supply system storing hot water heated by the heat pump unit 1 in the hot water storage tank 2, a plurality of hot water recovering ports D are formed on a side face of the hot water storage tank 2 at various height positions. The returned hot water is distributed to the plurality of hot water recovering ports D to be returned to the hot water storage tank 2 on the basis of a temperature of the returned hot water and a temperature distribution of hot water in the hot water storage tank 2 in returning the returned hot water from a liquid-liquid heat exchanger 3 to the hot water storage tank 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a return hot water recovery method and a hot water supply system, and more specifically, in a hot water supply system of a type that stores hot water generated by a heat pump in a hot water storage tank, the hot water radiated by a liquid heat exchanger is returned to the hot water storage tank. Regarding technology.

Recently, as a hot water supply system for general households, a hot water supply system of a type in which hot water heated and heated using an electric heat pump using natural refrigerant (CO ₂ ) as a heat source is stored in a hot water storage tank has been proposed. In this type of hot water supply system, hot water stored in the tank is supplied for hot water from hot water taps such as currants and showers (used for general hot water supply), and is provided for heating and bathing. It has been proposed that it can be heated and reheated by circulating it through a liquid heat exchanger.

  By the way, in the hot water supply system in which the hot water circulation path to the liquid heat exchanger is provided in the hot water storage tank as described above, the coefficient of performance (COP) indicating the operation efficiency of the heat pump is reduced when the tank is lifted by the operation of the heat pump. In order to prevent the hot water from being radiated by the liquid heat exchanger and reducing its temperature (hereinafter referred to as “return hot water”) to the hot water storage tank, the temperature stratification formed in the tank ( The device has been devised so as not to break the hot water layer naturally formed by the temperature difference of the hot water in the tank.

  Patent Document 1 and Patent Document 2 disclose a technique for returning hot water to a hot water storage tank so as not to break such temperature stratification. That is, each of these is provided with a temperature sensor for detecting the temperature of the hot water in the tank and a return pipe for returning the return hot water to the tank at different height positions of the hot water storage tank. While detecting the temperature stratification condition in the tank, it is configured to detect the temperature of the return warm water and collect the return warm water in the tank from the return pipe in the temperature stratification closest to the temperature of the return warm water in the tank. ing.

JP 2003-114053 A JP 2004-218920 A

  However, in the configuration in which one return pipe is selected in accordance with the temperature of the return warm water as described above, there are the following problems when the temperature of the return warm water does not match the temperature of the temperature stratification, and the improvement is desired. It was.

  That is, when the temperature of the return warm water does not match the temperature of the temperature stratification, the return warm water is returned to the temperature stratification on either the higher temperature side or the lower temperature side than that temperature. If is selected, the low temperature warm water at the bottom of the tank is not mixed with the return warm water, so the low temperature can be maintained, and the operation efficiency of the heat pump unit when the tank is raised can be maintained high (energy saving can be achieved) However, on the other hand, the hot water at the top of the tank is warmed and mixed with the hot water, and the hot water discharge capacity is reduced.

  On the other hand, if you choose to return the return warm water to the low temperature side, a lot of hot water remains in the upper part of the tank, and the high temperature hot water discharge capacity can be maintained, but the low temperature warm water at the bottom of the tank is mixed with the return warm water and the temperature rises. Can not be maintained, and the operation efficiency of the heat pump unit at the time of tank raising is lowered.

  The present invention has been made in view of such conventional problems, and the object of the present invention is to increase the operation efficiency of the heat pump unit at the time of raising the tank without reducing the high temperature hot water discharge capacity. The main object is to provide a method and a hot water supply system for recovering return warm water that can be maintained.

  In order to achieve the above object, a return hot water recovery method according to claim 1 of the present invention is a hot water supply system in which hot water heated by a heat pump unit is stored in a hot water storage tank, and a liquid is stored in the hot water storage tank. What has a hot water outlet pipe for supplying hot water to the heat exchanger, is a method of collecting the return hot water from the liquid heat exchanger to the hot water storage tank, the hot water storage tank in the height direction A plurality of hot water recovery ports are provided at different positions, and when returning the return hot water from the liquid heat exchanger to the hot water storage tank, the temperature of the return hot water and the temperature distribution of the hot water in the hot water storage tank are determined. Each return is detected, and the return hot water is distributed and returned to a plurality of hot water recovery ports according to the detected temperature of the return hot water and the temperature distribution of the hot water in the hot water storage tank.

  That is, according to the first aspect of the present invention, when returning the return hot water from the liquid heat exchanger to the hot water storage tank, the return hot water is recovered in accordance with the temperature of the return hot water and the temperature distribution of the hot water in the hot water storage tank. Since it is distributed and collected from the mouth to the hot water storage tank, the return hot water is less likely to mix with the hot hot water at the top of the tank and the low temperature hot water at the bottom of the tank. The operation efficiency of the heat pump unit can be maintained high, and a hot water supply system that can maintain a balance between both without sacrificing either the high temperature hot water discharge capacity or the operation efficiency of the heat pump unit as in the past can be provided.

  The return warm water recovery method according to claim 2 of the present invention is the return warm water recovery method according to claim 1, wherein the return warm water distribution is closest to the temperature of the return warm water in the hot water storage tank. The temperature stratification on both the high and low sides is set to be distributed at a predetermined distribution ratio.

  That is, in the invention according to claim 2, when the return hot water from the liquid heat exchanger is distributed and recovered to the hot water storage tank, the return hot water is returned to the high and low temperature stratification closest to the temperature of the return hot water in the hot water storage tank. It is possible to reduce the medium hot water generated by mixing the hot water in the hot water storage tank. In addition, the distribution ratio at the time of distributing the return hot water is set so that more return hot water returns to the temperature stratification closest to the temperature of the return hot water, for example, so that the generation of intermediate temperature water can be extremely reduced. it can.

  According to a third aspect of the present invention, there is provided a hot water supply system in which hot water heated by a heat pump unit is stored in a hot water storage tank for supplying hot water to the liquid heat exchanger. In the hot water storage pipe having the hot water outlet piping, the hot water storage tank is provided with a plurality of hot water recovery ports that also serve as hot water outlets for general hot water supply with different positions in the height direction, and each of these hot water recovery ports has a flow control valve. Each of the hot water return pipes from the liquid heat exchanger is connected to the mixing header via a flow rate adjusting valve, and is connected to each of the hot water recovery ports. A tank temperature sensor for detecting the temperature of hot water in the hot water storage tank is provided, and a return temperature sensor for detecting the temperature of the return hot water is also provided in the hot water return pipe, When returning the return hot water from the liquid-to-liquid heat exchanger to the hot water storage tank, the control means responds to the temperature of the return hot water detected by the return temperature sensor and the tank temperature sensor and the temperature distribution of the hot water in the hot water storage tank. And a control structure for controlling the flow rate adjusting valve so that the return hot water is recovered to the hot water storage tank through a plurality of hot water recovery ports.

  That is, in the invention according to claim 3, the hot water storage tank is provided with a plurality of hot water recovery ports that also serve as hot water outlets for general hot water supply with different positions in the height direction, and each of these hot water recovery ports has a flow rate adjustment. Each header is connected to the mixing header via a header pipe, and the hot water return pipe from the liquid-to-liquid heat exchanger is connected to the mixing header, so the flow control valve provided in the header pipe is controlled. By doing so, the return hot water from the liquid heat exchanger can be distributed and recovered to a plurality of hot water recovery ports. Moreover, since the distribution ratio at that time can be freely set by adjusting the valve opening degree and the valve opening time of the flow control valve, a hot water supply system suitable for carrying out the invention of claim 1 or 2 can be provided.

  According to a fourth aspect of the present invention, there is provided a hot water supply system according to the third aspect, wherein a bypass directly connected to the hot water storage tank is provided upstream of a flow rate adjustment valve provided in a hot water return pipe from the liquid heat exchanger. A pipe is provided, and a bypass valve is provided in the bypass pipe for adjusting the flow rate of the return warm water flowing through the bypass pipe.

  That is, in the invention according to claim 4, a bypass pipe directly connected to the hot water storage tank is provided in the hot water return pipe from the liquid heat exchanger, and a bypass valve for adjusting the flow rate is provided in the bypass pipe. Therefore, even when the hot water for general hot water supply is taken out from the mixed header, the return hot water to the hot water storage tank can be secured by opening the bypass valve, so that it is possible to prevent a decrease in the capacity of the liquid heat exchanger.

  According to a fifth aspect of the present invention, there is provided a hot water supply system in which hot water heated by a heat pump unit is stored in a hot water storage tank, in which hot water is supplied to the hot water storage tank for supplying hot water to the liquid heat exchanger. In one having a pipe, the hot water storage tank is provided with two hot water recovery ports at different heights, and the hot water outlet pipe has two hot water intake ports as hot water intake paths. The hot water outlet of the first flow path switching valve is connected to the liquid heat exchanger, and is connected to one hot water intake port of the first flow path switching valve. A warm water return pipe is connected to a warm water inlet of a second flow path switching valve having two hot water discharge ports, and one of the warm water discharge ports is the other warm water intake port of the first flow path switching valve Connected to one hot water recovery port of the hot water storage tank. Rutotomoni, the other of the hot water discharge port, characterized in that it is connected to the other of the hot water recovery port of the hot water storage tank.

  That is, in the invention according to claim 5, the hot water storage tank is provided with two hot water recovery ports at different positions in the height direction. The hot water outlet pipe for supplying hot water from the hot water storage tank to the liquid heat exchanger has one hot water intake port of the first flow path switching valve having two hot water intake ports as the hot water intake path. And the hot water outlet of the first flow path switching valve is connected to the liquid-to-liquid heat exchanger, and the hot water return pipe from the liquid-to-liquid heat exchanger has two hot water discharge ports. Connected to the hot water inlet of the second channel switching valve, and one of the hot water discharge ports is connected to the other hot water intake port of the first channel switching valve and one hot water recovery port of the hot water storage tank. In addition, since the other of the hot water discharge ports is connected to the other hot water recovery port of the hot water storage tank, by switching the flow paths of the first and second flow path switching valves, from the liquid heat exchanger The return hot water can be distributed and recovered to the two hot water recovery ports. Further, in this distribution and recovery, the distribution ratio of the return hot water to each hot water recovery port can be freely set by controlling the second flow path opening switching valve, and therefore suitable for the implementation of the invention of claim 1 or 2. A hot water supply system can be provided.

  According to the present invention, when returning the return hot water from the liquid heat exchanger to the hot water storage tank, the return hot water is returned to the hot water storage tank in the height direction according to the temperature of the return hot water and the temperature distribution of the hot water in the hot water storage tank. Since it is distributed and returned to a plurality of hot water recovery ports provided at different positions, the return hot water that has radiated heat from the liquid heat exchanger and the temperature has dropped is the hot hot water or tank in the upper part of the tank. Since it becomes difficult to mix with the low-temperature hot water in the lower part, it is possible to prevent a decrease in the high-temperature hot water discharge capacity and to maintain a high operating efficiency of the heat pump unit at the time of firing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1
FIG. 1 is a schematic configuration diagram showing an example of a hot water supply system to which the present invention is applied. This hot water supply system is a hot water supply system in which hot water heated by a heat source is stored in a hot water storage tank, and in the example shown in the figure, a general hot water supply (a hot water tap such as a caran or a hot water is dropped into a bath). ) And a hot water supply system that can perform both bathing simultaneously.

  Specifically, the illustrated hot water supply system includes a heat pump unit 1 as a heat source, a hot water storage tank 2 for storing hot water heated by the heat pump unit 1, a liquid heat exchanger 3 for reheating a bath, The main part includes a mixing header 4 to which piping for general hot water supply is connected and a controller (control means) 5 for controlling the entire system.

The heat pump unit 1 is an electric heat pump having a known configuration using a natural refrigerant (CO ₂ ), and a detailed description thereof is omitted here, but a heat exchanger for causing the refrigerant to absorb atmospheric heat. 41, an electric compressor 42 for compressing the refrigerant to a high temperature, a heat exchanger 43 for heating and heating water with the heat of the raised refrigerant, and a pressure for reducing the pressure of the compressed refrigerant The expansion valve 44 is a main part.

  And in the heat exchanger 43 of this heat pump unit 1, the water pipe 6 connected with the city water supply and the tank lower part of the said hot water storage tank 2, and the hot water heated and heated by the heat exchanger 43 are sent to the said hot water storage tank 2 And a circulating pump 8 is provided in either one of the water inlet pipe 6 or the hot water outlet pipe 7 (in the illustrated example, the case where it is provided on the side of the water inlet pipe 6 is shown). The circulating pump 8 is driven when the hot water storage tank 2 is lifted so that hot water is forcibly circulated between the hot water storage tank 2 and the heat pump unit 1.

  On the other hand, the hot water storage tank 2 is a sealed tank, and is connected to the hot water inlet A for taking in the hot water heated by the heat pump unit 1 and the liquid heat exchanger 3 for reheating the bath in the upper part of the tank. A hot water outlet B for taking out the hot water to be supplied is provided, the hot water inlet A is provided with the hot water outlet pipe 7, and the hot water outlet B is provided with a hot water outlet pipe 9 communicating with the liquid heat exchanger 3. It is connected. In addition, a water inlet / outlet C is provided at the lower part of the tank, and a lower pipe 10 is provided between the water inlet / outlet C and the water inlet pipe 6, and a water amount sensor 28 is provided in the lower pipe 10. Is provided.

  In this embodiment, the hot water storage tank 2 is provided with a plurality of hot water recovery ports D serving as hot water outlets for general hot water supply at different positions in the height direction (four in the illustrated example). Yes. Specifically, in the illustrated hot water supply system, the hot water recovery port D has a total of one location at the top of the hot water storage tank 2, two locations on the side of the tank, and a single location that also serves as the water inlet / outlet C at the bottom of the tank. Hot water recovery ports D are provided at four locations.

  Each of these hot water recovery ports D is connected to the mixing header 4 via a header pipe 11 provided with a flow rate adjusting valve 12. In the vicinity of each hot water recovery port D, a tank temperature sensor (temperature sensor) 13 for detecting the temperature of the hot water in the hot water storage tank 2 is disposed, and the detected value of each temperature sensor 13 is the controller 5. It is comprised so that it may be input.

  In the following description, in order to distinguish the individual hot water recovery ports D and the header pipes 11, the flow rate adjustment valves 12, and the tank temperature sensors 13 connected to the hot water recovery ports D from the other, It is assumed that “a” to “d” are added to the end of the reference numerals in order from the provided one.

  The liquid heat exchanger 3 is a heat exchanger for reheating a bath. The hot water outlet pipe 9 is connected to the primary hot water inlet side, and the outlet side of the hot water after returning heat (return hot water). Is connected to a hot water return pipe 14 having a flow rate adjusting valve 15, and the tip of the hot water return pipe 14 is connected to the mixing header 4. The hot water outlet pipe 9 is provided with a circulation pump 16 for bathing the bath. By driving the circulation pump 16, the hot water taken out from the hot water outlet B of the hot water storage tank 2 is liquefied. The heat exchanger 3 is configured to be supplied to the hot water inlet side.

  On the other hand, the warm water return pipe 14 is provided with a return temperature sensor (temperature sensor) 17 for detecting the temperature of the return warm water from the liquid heat exchanger 3, and the detected value of the return temperature sensor 17 is also temperature information. Is input to the controller 5. The hot water return pipe 14 is provided with a bypass pipe 18 branched from the upstream side of the flow rate adjusting valve 15 so that the bypass pipe 18 communicates with the hot water storage tank 2 via the flow rate adjusting valve 19. It is arranged.

  In addition, the secondary side of the liquid-liquid heat exchanger 3 is configured such that hot water (tub water) in the bathtub 20 driven by the liquid-liquid heat exchanger 3 circulates. Specifically, one end of the secondary side of the liquid-liquid heat exchanger 3 is connected to a circulation adapter (not shown) provided on the inner surface of the bathtub 20, and the liquid-temperature heat exchanger 3 is heated and heated. A recirculation pipe 21 for supplying the bathtub water to the circulation adapter (tub 20) is connected, and a recirculation return pipe 22 for returning the bathtub water to the liquid heat exchanger 3 is connected to the other end. The recirculation return pipe 22 is provided with a circulation pump 23 for circulating the bathtub water. By driving the circulation pump 23, hot water in the bathtub 20 is forcibly circulated to the secondary side of the liquid heat exchanger 3. It is comprised so that it can be made to.

  As will be described later, the mixing header 4 constitutes a part of a hot water return path for returning the hot water returned from the liquid heat exchanger 3 to the hot water storage tank 2 and mixes hot water flowing into the pipe during general hot water supply. Thus, the header device has a function of stabilizing the temperature of the hot water, and as described above, the header pipes 11a to 11d from the hot water storage tank 2 and the hot water return pipe 14 from the liquid heat exchanger 3 are connected. In addition, a general hot water supply pipe 25 provided with a hot water tap (hot water supply valve) 24 is connected. The pipe 25 is also provided with a hot water temperature sensor 26 for detecting the temperature of the hot water flowing in the pipe 25. The detected value of the hot water temperature sensor 26 is also supplied to the controller 5 as temperature information. The

  The controller 5 is a control device that controls the entire system, and includes a microcomputer having a predetermined control program as a main part. More specifically, the controller 5 includes an operation device (remote controller) 27 having a predetermined operation unit. Operation information input by the remote controller 27, the tank temperature sensors 13a to 13d, the return temperature sensor, and the like. 17 and further controlling the flow rate adjusting valves 12a to 12d, 15 and 19 based on temperature information inputted from the hot water supply temperature sensor 26, as well as operating control such as operation / stop of the heat pump unit 1 (details will be described later). To do).

The operation of the hot water supply system configured as described above will be described.
A: About Bath Reheating and Recovery of Returned Hot Water In the hot water supply system of this embodiment, when performing bath reheating, the controller 5 that has received a bath reheating operation with the remote controller 27 is configured to use the circulation pump 16 for reheating the bath. And the circulation pump 23 for bath water circulation is driven, and hot water is circulated to each of the primary side and the secondary side of the liquid heat exchanger 3. That is, when the circulation pump 16 is driven, hot hot water stored in the upper part of the hot water storage tank 2 is supplied from the hot water outlet B to the primary side of the liquid heat exchanger 3 through the hot water outlet pipe 9, and the circulation pump By driving 23, the bathtub water in the bathtub 20 is replenished and supplied from the return pipe 22 to the secondary side of the liquid-liquid heat exchanger 3, heated by the liquid-liquid heat exchanger 3 (heated), and reheated. It is returned to the bathtub 20 via the forward piping 21.

  On the other hand, regarding the return hot water on the primary side of the liquid heat exchanger 3, in the hot water supply system of the present invention, when the return hot water from the liquid heat exchanger 3 is collected in the hot water storage tank 2, the temperature of the return hot water and the hot water storage tank 2 are recovered. The return hot water is distributed and returned to a plurality of hot water recovery ports D provided in the hot water storage tank 2 at different positions in the height direction in accordance with the temperature distribution of the hot water inside.

  An example of the procedure for collecting the return warm water will be described with reference to FIG. In the following description, it is assumed that the temperature stratification in the hot water storage tank 2 is formed as shown in FIG. 2 and the temperature of the return hot water from the liquid heat exchanger 3 is 55 ° C.

  In this case, the tank temperature sensors 13a to 13d detect 13 ° at 80 ° C., 13b at 60 ° C., 13c at 30 ° C. and 13d at 15 ° C., and the return temperature sensor 17 detects 55 ° C. Information is input to the controller 5.

  When returning the return hot water to the hot water storage tank 2, the controller 5 depends on the temperature distribution of the hot water in the tank detected by the tank temperature sensors 13 a to 13 d and the temperature of the return hot water detected by the return temperature sensor 17. The return hot water is distributed to the plurality of hot water recovery ports D and returned to the hot water storage tank 2. Specifically, the controller 5 determines tank temperature sensors (in this case, 13b and 13c) that indicate the closest temperatures for both high and low with respect to the detection value of the return temperature sensor 17 (the temperature of the return warm water). The flow rate control valves 12b and 12c in the vicinity of the temperature sensors 13b and 13c are opened (the other flow rate adjustment valves 12a and 12d are fully closed), and the header pipes 11b and 11c and the hot water recovery ports Db and Dc are connected to the predetermined flow rate control valves 12b and 12c. The return hot water is distributed and collected at a distribution ratio P.

  As described above, in the hot water supply system of the present invention, the return hot water from the liquid heat exchanger 3 is distributed and recovered to the two high temperature stratifications indicating the temperature closest to the temperature of the return hot water. By returning the hot water into the hot water storage tank 2, it is possible to prevent one of the high temperature hot water discharge capacity and the operation efficiency of the heat pump unit 1 from being significantly impaired.

  Here, the distribution ratio P is determined as follows, for example, based on the temperature difference between the temperature of the return hot water and each temperature of the two layers of the high and low temperature layers indicating the temperature closest to the temperature of the return hot water. Is done. That is, as described above, when the temperature of the return warm water is 55 ° C., the value x obtained by subtracting the temperature (55 ° C.) of the return warm water from the temperature of the temperature stratification (60 ° C.) on the high temperature side, and the return warm water Depending on the ratio (x: y = 1: 5) of the value y obtained by subtracting the temperature (30 ° C.) of the low temperature side temperature stratification from the temperature (55 ° C.), the one with the smaller temperature difference from the return hot water The distribution ratio to the temperature stratification side (in this case, the high temperature side) is set to be large. That is, in this case, the distribution ratio P between the high temperature side and the low temperature side is set to be 5: 1.

  As described above, the distribution ratio P can be configured so that the controller 5 is uniformly determined based on a predetermined calculation formula, but is obtained based on the calculation formula, for example. It is also possible to configure so that the distribution ratio P can be corrected by operating the remote controller 27 or the like.

  That is, in the above-described example, the distribution ratio P is set so as to return more warm water to the temperature stratification with the smaller temperature difference from the return warm water, but depending on whether the returned warm water is returned to the higher temperature side or the lower temperature side. Since the high temperature hot water discharge capacity and the operation efficiency of the heat pump unit 1 are affected, whether the high temperature hot water discharge capacity is important (function-oriented) or the operation efficiency of the heat pump unit 1 (energy-saving priority) is determined by operating the remote controller 27. The distribution ratio A obtained by the above calculation can be modified based on this selection.

  For example, when the distribution ratio P between the high temperature side and the low temperature side obtained by calculation is 5 to 1, and the user selects function-oriented, the ratio of the distribution ratio P to the high temperature side is lowered to reduce the temperature. Increase the ratio to the side (for example, correct to 4 to 2), and conversely if energy saving is selected, adopt a configuration that increases the ratio to the high temperature side and decreases the ratio to the low temperature side Can do.

  As for the specific procedure of the distribution and recovery of the return warm water, as described above, when returning the return warm water at a ratio of 5: 1 to the temperature stratification at 60 ° C. and 30 ° C., the controller 5 has a temperature of 60 ° C. Open the flow control valves 12b and 12c of the header pipes 11b and 11c connected to the hot water recovery port Db in the stratification and the hot water recovery port Dc in the temperature stratification at 30 ° C. (other flow control valves 12a and 12d are fully closed). The flow rate adjusting valves 12b and 12c are controlled so that the distribution ratio to the hot water recovery ports Db and Dc is 5 to 1 by adjusting the valve opening or the valve opening time.

  As described above, in the hot water supply system of the present invention, when returning the return hot water from the liquid heat exchanger 3 to the hot water storage tank 2 from the plurality of hot water recovery ports D, the temperature stratification of the two layers high and low closest to the temperature of the return hot water is performed. On the other hand, since the distribution ratio P is determined so as to return most of the warm water to the temperature stratification with a small temperature difference according to the temperature difference with the return warm water, the influence on the temperature stratification formed in the hot water storage tank 2 is affected. The returned warm water can be returned to the hot water storage tank 2 in a small state.

B: General Hot Water Supply Next, general hot water supply from the hot water tap 24 will be described. The hot water supply set temperature in the general hot water supply is set by the remote controller 27, and the information is given to the controller 5. The controller 5 controls the flow rate adjusting valves 12 a to 12 d so that hot water having a hot water supply set temperature is discharged from the hot water tap 24 based on the setting by the remote controller 27.

  In this control, the controller 5 is configured to actively use so-called medium-temperature water (specifically, hot water of about 20 ° C. to 60 ° C.) in the hot water storage tank 2 for general hot water supply. Specifically, for example, when the hot water supply set temperature set by the remote controller 27 is 40 ° C. and the temperature distribution of the hot water in the hot water storage tank 2 is distributed as shown in FIG. In generating hot water of 40 ° C., which is the preset temperature, hot water of two layers of high and low temperature (in this case, 60 ° C. and 30 ° C.) showing the temperature closest to the hot water supply preset temperature (40 ° C.) is used.

  That is, based on the temperature information obtained from the tank temperature sensors 13a to 13d, the controller 5 determines the tank temperature sensors 13b and 13c that indicate the closest temperatures for both high and low relative to the hot water supply set temperature (40 ° C.). The flow rate control valves 12b and 12c in the vicinity of the temperature sensors 13b and 13c are opened (the other flow rate adjustment valves 12a and 12d are fully closed), their valve opening degrees are adjusted, and the hot water supply set temperature is set in the mixing header 4 (40 ° C) warm water is generated. As a result, hot water generated in the mixing header 4, that is, hot water having a hot water supply set temperature is discharged from the hot water tap 24.

  On the other hand, also when the hot water supply set temperature set by the remote controller 27 exceeds the temperature range of the medium temperature water and is set to a high temperature or a low temperature, the controller 5 performs the same control as the above-described control. That is, for example, a case where the hot water supply set temperature is 65 ° C. will be described as an example. In this case, the tank temperature sensors 13a and 13b indicating the temperatures closest to the hot water set temperature (65 ° C.) are determined. The flow rate control valves 12a and 12b in the vicinity of the temperature sensors 13a and 13b are opened (the other flow rate adjustment valves 12c and 12d are fully closed), their valve openings are adjusted, and the hot water supply set temperature is set in the mixing header 4 (65 ° C) warm water is generated. As a result, hot water generated in the mixing header 4, that is, hot water having a hot water supply set temperature is discharged from the hot water tap 24.

  In addition, although the control in the general hot water supply mentioned above demonstrated the case where the reheating operation of a bath was not performed (in the case of a general hot water supply alone), when the reheating operation of a bath is performed simultaneously, return to warm water Since the return hot water returns from the pipe 14 into the mixing header 4, the controller 5 uses temperature information from the return temperature sensor 17 in addition to the hot water supply set temperature and the temperature information from the tank temperature sensors 13 a to 13 d described above. The valve opening degree of the flow control valve 15 is also adjusted so that the temperature of the hot water in the mixing header 4 is controlled to the hot water supply set temperature. At that time, if the flow rate of the return hot water is too narrowed by the flow rate control valve 15, the ability to retreat the bath is lowered. In this case, the flow rate adjustment valve 19 of the bypass pipe 18 is opened (the valve opening degree of the flow rate adjustment valve 19 ) And adjust so that the ability of bathing is not reduced.

  With regard to this bath reheating operation, as another embodiment, when the hot water tap is opened during the bath reheating operation and general hot water supply is performed, the bath reheating operation is temporarily stopped and the general hot water supply is stopped. It may be configured so that the bath reheating operation is resumed after the operation is completed. Further, when a bath reheating operation is requested during the general hot water supply, h, the bath reheating operation is once waited, and the bath reheating operation is started after the general hot water supply is finished. Good.

  Moreover, although the case where the circulation circuit for bath reheating was connected to the secondary side of the liquid-liquid heat exchanger 3 was shown in the above-described embodiment, as a load connected to the secondary side of the liquid-liquid heat exchanger 3 A hot water heater (circulation circuit for hot water heating) can also be used. FIG. 3 shows an example in which a circulation circuit for hot water heating is connected to the secondary side of the liquid-to-liquid heat exchanger 3, and in the illustrated case, the secondary side of the liquid-to-liquid heat exchanger 3 is connected to the heating side. A heating return pipe 30 and a heating return pipe 31 connected to the header 29 are connected, and individual hot water heaters (in the illustrated example, a bathroom dryer 32 and a floor heating panel 33) are connected to the header 29 by heating. The circulation pump 34 is configured so that the heat medium can be forcedly circulated between the hot water heaters 32 and 33 and the secondary side of the liquid heat exchanger 3.

Embodiment 2
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic configuration diagram illustrating an example of a hot water supply system according to the second embodiment.

  As shown in the figure, this hot water supply system is a hot water supply system in which hot water heated by a heat pump unit is stored in a hot water storage tank, and the hot water is supplied to the hot water storage tank for supplying hot water to the liquid heat exchanger. Although the configuration is the same as that of the first embodiment described above in that it has a piping and a hot water storage tank with different positions in the height direction and includes a plurality of hot water recovery ports, the hot water outlet for general hot water supply is independent. The point provided, the path of the return hot water from the liquid heat exchanger, and the like are different from the first embodiment.

  Specifically, the illustrated hot water supply system includes a heat pump unit 101 as a heat source, a hot water storage tank 102 for storing hot water heated by the heat pump unit 101, and a liquid heat exchanger 103 for heating a heating heat medium. And a controller (control means) 104 for controlling the entire system.

The heat pump unit 101 is an electric heat pump having a known configuration using a natural refrigerant (CO ₂ ), and a detailed description thereof is omitted here, but a heat exchanger for causing the refrigerant to absorb atmospheric heat. 131, an electric compressor 132 for compressing the refrigerant to a high temperature, a heat exchanger 133 for heating and heating water with the heat of the raised refrigerant, and a pressure for reducing the pressure of the compressed refrigerant The expansion valve 134 is a main part.

  In the heat exchanger 133 of the heat pump unit 101, a water pipe 105 connected to the city water supply and the tank lower part of the hot water storage tank 102 and hot water heated by the heat exchanger 133 are heated and stored in the hot water storage tank 102. And a circulating pump 107 is provided in either one of the water inlet pipe 105 or the hot water outlet pipe 106 (provided on the side of the water inlet pipe 105 in the illustrated example). By driving this circulation pump 107 when the tank 102 is lifted, the hot water is forcibly circulated between the hot water storage tank 102 and the heat pump unit 101.

  On the other hand, the hot water storage tank 102 is a hermetically sealed tank, and has a hot water inlet E for taking hot water heated by the heat pump unit 101 into the tank and taking out hot water for general hot water supply. A hot water outlet F and a hot water outlet G for taking out hot water as a heat source of the liquid heat exchanger 103 for heating the heating medium are provided.

  The hot water inlet E is connected to the hot water outlet pipe 106, the hot water outlet F is connected to a hot water supply pipe 108 connected to a hot water tap (not shown), and the hot water outlet G is connected to a liquid heat exchanger. A hot water going-out pipe 109 communicating with 103 is connected (details will be described later).

  In addition, a water inlet / outlet H is provided at the lower part of the tank, and a lower pipe 110 is provided between the water inlet / outlet H and the water inlet pipe 105, and a water amount sensor 111 is provided in the lower pipe 110. Is provided.

  In this embodiment, the hot water storage tank 102 is provided with a plurality of hot water recovery ports I for recovering the hot water returned from the liquid heat exchanger 103 to the hot water storage tank 102 at different positions in the height direction. ing. Specifically, in the illustrated hot water supply system, as the hot water recovery port I, two hot water recovery ports Ia and Ib are provided on the side surface of the hot water storage tank 102.

  These hot water recovery ports Ia and Ib are opened at a height position where so-called medium-temperature water (specifically, hot water of about 20 ° C. to 60 ° C.) tends to accumulate in the hot water storage tank 102, that is, in the middle of the tank. In the present embodiment, the upper hot water recovery port Ia is opened slightly above the middle of the tank (specifically, at a height of about 2/3 of the entire tank length), and the lower hot water recovery port Ib is The tank is opened below the tank (specifically, at a height of about 1/3 of the total length of the tank).

  In addition, a plurality of temperature sensors 120 for detecting the temperature (temperature distribution) of the hot water in the tank are disposed in each part of the hot water storage tank 102. Specifically, a temperature sensor 120 indicated by 120a in the vicinity of the hot water outlet G, 120b and 120c in the vicinity of the hot water recovery ports Ia and Ib, and 120d in the vicinity of the water inlet / outlet H are provided. The detection values of each of these temperature sensors 120 are given to the controller 104 as temperature information.

  Next, the connection between the hot water storage tank 102 and the liquid-liquid heat exchanger 103 will be described in detail.

  That is, the warm water outlet pipe 109 is connected to one hot water intake port a of the first flow path switching valve 112 having two systems of hot water intake ports a and b and one hot water outlet c. The first flow path switching valve 112 is a valve device configured to be able to switch between the hot water intake ports a and b under the control of the controller 104, and the hot water outlet c is a circulation for heating the heating medium. The pipe 114 is connected to the primary hot water containing side of the liquid heat exchanger 103 via a pipe 113.

  The primary hot water outlet side of the liquid-to-liquid heat exchanger 103 is connected to a second flow path switching valve 116 having one hot water inlet d and two hot water outlets e and f via a pipe 115. Connected to hot water inlet d. Similarly to the first flow path switching valve 112 described above, the second flow path switching valve 116 is also configured by a valve device configured to be able to switch the hot water discharge ports e and f under the control of the controller 104. .

  One of the discharge ports (discharge port e) is connected to the other hot water intake port b of the first flow path switching valve 112 by a pipe 117. A branch pipe 118 is provided in the middle of the pipe 117 connecting the first flow path switching valve 112 and the second flow path switching valve 116, and the branch pipe 118 is provided in the hot water storage tank 102. Of the two hot water recovery ports I, the upper hot water recovery port Ia is connected. The other of the discharge ports (discharge port f) is connected to the lower hot water recovery port Ib via a pipe 119.

  The liquid-liquid heat exchanger 103 is a heat exchanger for heating a heating medium for hot water heating, and heats the heating heating medium flowing on the secondary side by using hot water supplied to the primary side as a heat source. Let

  The secondary side of the liquid heat exchanger 103 is connected to a heating forward pipe 122 and a heating return pipe 123 connected to the heating header 121, and individual hot water heaters (illustrated examples) are connected to the header 121. Then, the bathroom dryer 124 and the floor heating panel 125) are connected by piping, and a heating medium circulating between the hot water heaters 124 and 125 and the secondary side of the liquid heat exchanger 103 is connected by a heating circulation pump 126. It is configured to allow forced circulation.

  The controller 104 is a control device that controls the entire system, and includes a microcomputer having a predetermined control program as a main part. More specifically, the controller 104 includes an operation device (remote controller) 127 having a predetermined operation unit. Operation information input from the remote controller 127 and input from the tank temperature sensors 120a to 120d. In addition to controlling the first and second flow path switching valves 112 and 116 based on the temperature information, operation control such as operation / stop of the heat pump unit 101 is performed (details will be described later).

Next, operation | movement of the hot water supply system of this embodiment comprised in this way is demonstrated.
C: Heating Operation In the hot water supply system shown in the present embodiment, when an operation for instructing the start of the heating operation is performed with the remote controller 127, the controller 104 that has received the operation performs the operation of the first flow path switching valve 112. The flow path is set to ac (b is fully closed), the flow path of the second flow path switching valve 116 is set to df (e is fully closed), and the circulation pump 113 is driven in this state.

  Thereby, at the beginning of the heating operation, that is, at the initial stage of the heating operation, hot hot water (for example, 80 ° C. hot water) stored in the upper part of the hot water storage tank 102 is supplied from the hot water outlet G to the hot water outlet pipe. 109, the heating temperature of the heat medium supplied to the primary side of the liquid-to-liquid heat exchanger 103 via the first flow path switching valve 112 and flowing on the secondary side is started.

  By the way, in such an initial stage of the heating operation, the temperature of the heating heat medium flowing on the secondary side of the liquid heat exchanger 103 is not sufficiently increased, so that the liquid heat exchange from the hot water storage tank 102 is performed. The hot water supplied to the vessel 103 dissipates a lot of heat in the liquid-to-liquid heat exchanger 103, and the temperature of the return hot water is significantly reduced. Therefore, in the initial stage of the heating operation, the controller 104 sets the flow path of the second flow path switching valve 116 so that the low temperature return warm water is not mixed with the high temperature warm water stored in the upper part of the tank. df (e is fully closed) is set so that the low temperature return warm water is returned from the warm water recovery port Ib to the lower part of the tank.

  After a while after the heating operation is started, the temperature of the heating heat medium flowing on the secondary side of the liquid-liquid heat exchanger 103 rises, the heat load of the liquid-liquid heat exchanger 103 decreases, and the liquid heat The temperature of the return warm water from the exchanger 103 rises. Therefore, as the next step, the controller 104 sets the flow path of the second flow path switching valve 116 to both df and de (e, f) as the temperature of the return hot water increases. Both are fully opened), and both the two channels of the second channel switching valve 116 are opened.

  Thereby, the return hot water from the liquid heat exchanger 103 returns to the hot water storage tank 102 from both the hot water recovery ports Ia and Ib. In other words, since the temperature of the return warm water has risen, if all the return warm water is returned to the lower part of the tank, the temperature of the low temperature warm water at the lower part of the tank will rise, reducing the operating efficiency of the heat pump unit 101 at the time of firing. In the second stage, the controller 104 is configured to reduce the amount of warm water returning to the lower part of the tank in order to prevent such a decrease in operating efficiency.

  Here, regarding the timing of switching the flow paths of the first and second flow path switching valves 112 and 116, for example, a temperature sensor (not shown) for detecting the temperature of the return hot water is arranged in the hot water return pipe 115. In addition, the controller 104 can be configured to determine (specifically, determine whether or not the return hot water has reached a predetermined temperature) based on the detection result of the temperature sensor. It is also possible to configure the controller to measure the elapsed time from the heating operation start operation at 127 and to switch with the passage of a predetermined time.

  In the above-described example, as the second stage, the case where both d and e of the second flow path switching valve 116 are fully opened is shown. However, as shown in the first embodiment, the return hot water Based on the temperature of the hot water storage tank 102 and the temperature distribution in the hot water storage tank 102, the hot water can be recovered from the hot water recovery ports Ia and Ib at a predetermined distribution ratio. That is, also in the hot water supply system of the present embodiment, the distribution ratio to the hot water recovery ports Ia and Ib is adjusted by adjusting the opening degree of each of the valves d and e and adjusting the opening time of the valves d and e. Can be set.

  When the heating operation is continued and the heat load of the liquid heat exchanger 103 is further reduced, the controller 104 sets the flow path of the first flow path switching valve 112 to bc as the next stage. (A is fully closed) The flow path of the second flow path switching valve 116 is set to df (e is fully closed).

  That is, when a certain amount of time has elapsed from the start of the heating operation and the heating circuit side is in a so-called equilibrium state, the controller 104 stops taking out hot hot water from the upper part of the hot water storage tank 102 and accumulates in the middle of the hot water storage tank 102. Hot water is used as a heat source for heating medium heating. In other words, at this stage, the hot water recovery port Ia is used as a hot water outlet to the liquid-liquid heat exchanger 103. On the other hand, since the temperature of the return warm water decreases as the temperature of the warm water supplied to the liquid heat exchanger 103 decreases, the return warm water is returned to the lower part of the tank.

  It should be noted that a temperature sensor (not shown) for detecting the temperature of the return hot water is arranged in the hot water return pipe 115 in the same manner as described above to determine whether or not the heating circuit is in an equilibrium state. In addition, the controller 104 can be configured to make a determination based on the detection result of the temperature sensor (more specifically, the heating circuit is determined to be in an equilibrium state when the change in the temperature of the return hot water decreases). It is also possible to cause the controller to measure the elapsed time from the heating operation start operation in and to determine that the vehicle is in an equilibrium state after a predetermined time.

  When the heat load of the liquid heat exchanger 103 further decreases, as a final step, the controller 104 sets the flow path of the second flow path switching valve 116 to de (f is fully closed). . That is, in this last stage, since the heat load by the liquid heat exchanger 103 is extremely small and there is almost no heat radiation by the heat exchanger, the return hot water from the liquid heat exchanger 103 is supplied to the second and first flow paths. The liquid is again returned to the liquid heat exchanger 103 via the switching valves 116 and 112. That is, in this case, the warm water recovery port Ia does not take out or collect the warm water, and the return warm water flows to the first flow path switching valve 112, and the first flow path switching valve 112, the liquid-liquid heat exchanger 103 circulates between the second flow path switching valve 116.

  As described above, in the hot water supply system shown in the present embodiment, the first condition depends on the usage state of the load connected to the secondary side of the liquid-liquid heat exchanger 103, the temperature of the return hot water from the liquid-liquid heat exchanger 103, and the like. And the second flow path switching valves 112 and 116 are configured to switch the flow path, so that the medium-temperature water in the hot water storage tank 102 can be actively used, and there is little destruction of temperature stratification due to the return hot water, It is possible to provide a hot water supply system that can cope with high-temperature hot water discharge and that is less likely to reduce the operation efficiency of the heat pump unit 101.

D: General Hot Water Supply In the hot water supply system of the present embodiment, the hot water outlet F for general hot water is provided at the upper part of the hot water storage tank 102, and the hot water supply pipe 108 is connected to the outlet F. Is always capable of supplying hot water. Therefore, if a hot-water tap such as a mixed water tap is provided at the tip of the hot-water supply pipe 108, hot water can be discharged at a desired temperature.

  In addition, embodiment mentioned above shows the preferred embodiment of this invention, Comprising: This invention is not limited to these, A various design change is possible within the range.

  For example, in the above-described embodiment, a case where a heat pump unit using a natural refrigerant is used as a heat source of a hot water supply system is shown. However, the present invention is a type of storing hot water heated by a heat source and heated in a hot water storage tank. If it is a hot water supply system, it is also possible to use a heat pump unit, cogeneration, etc. using other refrigerants as a heat source.

  In the first embodiment described above, the case where the hot water recovery port D in the lower part of the tank is provided so as to be used also as the water inlet / outlet C is shown. Of course, the hot water recovery port D can be provided separately from the water inlet / outlet C. It is. Moreover, the hot water collection | recovery port D provided in the hot water storage tank 2 should just be provided with two or more positions in the height direction, and is not limited to four places like the example of illustration.

  In addition, although Embodiment 2 mentioned above showed the case where a hot-water heating appliance was used as a load of the liquid-liquid heat exchanger 103, the bath follower as shown in Embodiment 1 is used as the load of the liquid-liquid heat exchanger 103. It is also possible to use a whisper circuit. In that case, when performing normal bath replenishment, the hot water taken out from the hot water outlet G at the top of the hot water storage tank 102 is supplied to the liquid heat exchanger 103. For example, in the case of slowly chasing the bather without discomfort, the hot water recovery port Ia is switched by switching the flow paths of the first and second flow path switching valves 112 and 116. The liquid heat exchanger 103 is heated using the hot water from. That is, in this case, the flow path of the first flow path switching valve 112 is set to bc, and the flow path of the second flow path switching valve 116 is set to be df.

It is a schematic structure figure showing an example of a hot-water supply system concerning the present invention. It is explanatory drawing for demonstrating the collection | recovery procedure of the return warm water in the hot-water supply system. It is a schematic block diagram which shows the modification of the secondary side of the liquid-liquid heat exchanger in the hot-water supply system. It is a schematic block diagram which shows 2nd embodiment of the hot water supply system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Heat pump unit 2,102 Hot water storage tank 3,103 Liquid heat exchanger 4 Mixing header 5,104 Controller 11a-11d Header piping 12a-12d Flow control valve 13a-13d Temperature sensor 27,127 Remote control 112 First flow Channel switching valve 116 Second channel switching valve A, E Hot water inlet B, F, G Hot water outlet C, H Water outlet D, I Hot water recovery port

Claims (5)

A hot water supply system for storing hot water heated by a heat pump unit in a hot water storage tank, wherein the hot water storage tank has hot water outlet piping for supplying hot water to a liquid heat exchanger. A method for recovering the hot water returned from the heat exchanger to the hot water storage tank,
In the hot water storage tank, a plurality of hot water recovery ports are provided at different positions in the height direction,
When returning the return hot water from the liquid heat exchanger to the hot water storage tank, the temperature of the return hot water and the temperature distribution of the hot water in the hot water storage tank are respectively detected.
A return hot water recovery method, wherein the return hot water is distributed and returned to a plurality of hot water recovery ports according to the detected temperature of the return hot water and the temperature distribution of the hot water in the hot water storage tank.   The return hot water is distributed so as to be distributed at a predetermined distribution ratio to temperature stratifications on both sides of the hot and cold water closest to the temperature of the return hot water in the hot water storage tank. Hot water recovery method. A hot water supply system that stores hot water heated by a heat pump unit in a hot water storage tank, and has a hot water supply pipe for supplying hot water to the liquid heat exchanger in the hot water storage tank.
In the hot water storage tank, a plurality of hot water recovery ports serving as hot water outlets for general hot water supply are provided with different positions in the height direction,
Each of these hot water recovery ports is connected to the mixing header via a header pipe provided with a flow rate adjustment valve, and a hot water return pipe from the liquid heat exchanger is connected to the mixing header via a flow rate adjustment valve. ,
A tank temperature sensor for detecting the temperature of the hot water in the hot water storage tank is provided in the vicinity of each hot water recovery port, and a return temperature sensor for detecting the temperature of the return hot water is also provided in the hot water return pipe.
When returning the return hot water from the liquid heat exchanger to the hot water storage tank, the control means responds to the temperature of the return hot water detected by the return temperature sensor and the tank temperature sensor and the temperature distribution of the hot water in the hot water storage tank. A hot water supply system comprising a control structure for controlling the flow rate adjustment valve so that the return hot water is recovered to the hot water storage tank through a plurality of hot water recovery ports.   A bypass pipe directly connected to the hot water storage tank is provided on the upstream side of the flow rate adjustment valve provided in the hot water return pipe from the liquid heat exchanger, and the flow rate of the return hot water flowing through the bypass pipe is adjusted to the bypass pipe. The hot water supply system according to claim 3, wherein a bypass valve is provided. In a hot water supply system that stores hot water heated by a heat pump unit in a hot water storage tank, the hot water storage tank has a hot water outlet pipe for supplying hot water to a liquid heat exchanger.
The hot water storage tank is provided with two hot water recovery ports at different height positions,
The hot water outlet pipe is connected to one hot water intake port of a first flow path switching valve having two hot water intake ports as a hot water intake path, and the hot water of the first flow path switching valve The outlet is connected to the liquid heat exchanger,
A hot water return pipe from the liquid heat exchanger is connected to a hot water inlet of a second flow path switching valve having two hot water discharge ports, and one of the hot water discharge ports is the first flow path switching The other hot water intake port of the valve is connected to one hot water recovery port of the hot water storage tank, and the other of the hot water discharge port is connected to the other hot water recovery port of the hot water storage tank. Hot water system.

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