JP6646554B2 - Cold and hot water supply device - Google Patents

Description

  The present invention relates to a cold / hot water supply device.

  Various devices utilizing thermoacoustic phenomena that exchange energy between heat and sound waves have been put into practical use. For example, a thermoacoustic heat pump hot water supply that has a U-shaped resonance tube filled with a working fluid, pumps heat in a low-temperature stack by acoustic vibration generated in a high-temperature stack, and heats water with a high-temperature feedwater heat exchanger An apparatus is known (for example, see Patent Document 1).

JP 2005-188846 A

  However, in the thermoacoustic heat pump water heater according to Patent Literature 1, the acoustic wave generated in the U-shaped resonance tube is a standing wave, so that it may be difficult to improve the heat exchange efficiency.

  The present invention has been made in view of the above, and an object of the present invention is to provide a cold and hot water supply device with improved energy conversion efficiency.

  According to the cold and hot water supply device according to one aspect of the present invention, a loop-shaped thermoacoustic tube, an acoustic wave generator provided in the thermoacoustic tube to generate an acoustic wave, and the thermoacoustic tube connected to the thermoacoustic tube, A loop-shaped heat pump pipe through which an acoustic wave is guided, a heat exchanger provided in the heat pump pipe to perform heat exchange, a heater to heat the acoustic wave generator, the acoustic wave generator, and the heat exchanger And a preheater for preheating water supplied from the water supply to the heat exchanger with waste heat of the heater, and the acoustic wave generator is heated by the heater. A high-temperature portion, and a low-temperature portion cooled by water supplied from the water supply device, wherein the heat exchanger is a low-temperature heat exchange portion for cooling water supplied from the water supply device, A high-temperature heat exchange section for heating water preheated by the preheater. That.

  According to the embodiment of the present invention, a cold / hot water supply device with improved energy conversion efficiency is provided.

It is a figure which illustrates the structure of the cold and hot water supply device in a 1st embodiment. It is a figure which illustrates the structure containing the control part of the cold / hot water supply device in 1st Embodiment. It is a figure which illustrates the structure of the hot and cold water supply device in a 2nd embodiment. It is a figure which illustrates the structure containing the control part of the cold / hot water supply device in 2nd Embodiment. It is a figure explaining the high temperature control of the cold and hot water supply device in a 2nd embodiment. It is a figure explaining middle temperature control of a cold and hot water supply device in a 2nd embodiment. It is a figure explaining low temperature control of the cold and hot water supply device in a 2nd embodiment. It is a figure which illustrates the flow chart of the tap water temperature control processing in a 2nd embodiment.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

[First Embodiment]
FIG. 1 is a diagram illustrating a cold / hot water supply device 100 according to the first embodiment.

  As shown in FIG. 1, the cold / hot water supply device 100 includes an acoustic wave generation unit 10, a heat pump unit 20, and a water supply unit 30.

  The acoustic wave generator 10 includes a thermoacoustic tube 11, a heater 40, and an acoustic wave generator HP1. The acoustic wave generator HP1 has a high temperature section 12, a low temperature section 13, and a stack 14.

  The thermoacoustic tube 11 is formed in a loop shape, and an acoustic wave generated by the stack 14 propagates. Although the thermoacoustic tube 11 in the present embodiment is formed of a steel tube so as to withstand heat and internal pressure, the material, the cross-sectional shape, and the like are not limited thereto.

  The high-temperature portion 12 is formed, for example, of a metal material into a cylindrical shape having a plurality of heat transfer fins inside. The high temperature section 12 is connected to the thermoacoustic tube 11 and is heated by the heater 40.

  The heater 40 is, for example, a burner and heats the high temperature section 12. The heater 40 heats the high temperature part 12 to about 600 ° C., for example.

  The low-temperature part 13 is formed in a cylindrical shape from, for example, a metal material. The low-temperature portion 13 has a flow path formed in the peripheral wall and through which water flows, and a plurality of heat transfer fins formed in the cylinder and transmitting heat. The low-temperature section 13 is connected to the thermoacoustic tube 11 and is cooled by water supplied from the water supply device 31 and flowing through the flow path in the peripheral wall. The low-temperature section 13 is cooled to about 20 ° C. by supplying normal-temperature water from the water supply device 31, for example. The low-temperature section 13 may have a configuration different from that of the present embodiment as long as water can be supplied from the water supply device 31.

  The stack 14 is, for example, formed in a cylindrical shape from a metal material. The inside of the stack 14 has a honeycomb structure in which a plurality of thin tubes are arranged. The stack 14 is provided between the high-temperature section 12 and the low-temperature section 13 so that the inner thin tube communicates with the thermoacoustic tube 11 via the high-temperature section 12 and the low-temperature section 13.

  In the stack 14, an acoustic wave is generated by a thermoacoustic phenomenon due to a temperature gradient generated between the high temperature section 12 and the low temperature section 13. The acoustic wave generated in the stack 14 becomes a traveling wave propagating in the thermoacoustic tube 11, and is amplified, for example, by looping the thermoacoustic tube 11 in the direction of an arrow in FIG.

  The heat pump unit 20 has a heat pump tube 21, a mixer 50, and a heat exchanger HP2. The heat exchanger HP2 has a low-temperature heat exchange unit 22, a high-temperature heat exchange unit 23, and a stack 24.

  The heat pump tube 21 is formed in a loop shape, and is connected to the thermoacoustic tube 11 by a connecting portion 15. A part of the acoustic wave propagating in the thermoacoustic tube 11 is guided to the heat pump tube 21 through the connecting portion 15. The acoustic wave guided to the heat pump tube 21 loops inside the heat pump tube 21. Although the heat pump tube 21 in the present embodiment is formed of a steel tube so as to withstand heat and internal pressure, the material, the cross-sectional shape, and the like are not limited thereto.

  The low-temperature heat exchange section 22 is formed in a cylindrical shape by, for example, a metal material. The low-temperature heat exchange section 22 has a flow path formed in the peripheral wall and through which water flows, and a plurality of heat transfer fins formed in the cylinder and transmitting heat. The low-temperature heat exchange section 22 is connected to the heat pump pipe 21, and the water supplied from the water supply 31 flows through the flow path in the peripheral wall. Note that the low-temperature heat exchange unit 22 may have a configuration different from that of the present embodiment as long as water can be supplied from the water supply device 31.

  The high-temperature heat exchange section 23 is formed in a tubular shape, for example, from a metal material. The high-temperature heat exchange section 23 has a flow path formed in the peripheral wall and through which water flows, and a plurality of heat transfer fins formed in the cylinder and transmitting heat. The high-temperature heat exchange unit 23 is connected to the heat pump pipe 21, and water supplied from the water supply unit 31 flows through a flow path in the peripheral wall. Note that the high-temperature heat exchange unit 23 may have a configuration different from that of the present embodiment as long as water can be supplied from the water supply device 31.

  The stack 24 is formed, for example, in a cylindrical shape from a metal material. The inside of the stack 24 has a honeycomb structure composed of a plurality of thin tubes. The stack 24 is provided between the low-temperature heat exchange unit 22 and the high-temperature heat exchange unit 23 so that the inner thin tube communicates with the heat pump tube 21 via the low-temperature heat exchange unit 22 and the high-temperature heat exchange unit 23.

  In the stack 24, a thermoacoustic phenomenon occurs due to an acoustic wave propagating through the heat pump tube 21, and a temperature gradient is generated by pumping heat from the low-temperature heat exchange unit 22 to the high-temperature heat exchange unit 23.

  As the heat is pumped by the stack 24, the water supplied from the water supply 31 to the low-temperature heat exchange unit 22 is deprived of heat and cooled. As a result, for example, cold water cooled to 10 ° C. or lower is discharged from the low-temperature heat exchange unit 22. Moreover, the water supplied from the water supply device 31 to the high-temperature heat exchange unit 23 is heated by the heat being pumped up by the stack 24. As a result, for example, hot water heated to about 80 ° C. is discharged from the high-temperature heat exchange unit 23.

  The mixer 50 is connected to the low-temperature heat exchange unit 22 and the high-temperature heat exchange unit 23, and mixes the cold water discharged from the low-temperature heat exchange unit 22 and the hot water discharged from the high-temperature heat exchange unit 23, for example. The hot water adjusted to a temperature set between 40 ° C. and 80 ° C. is discharged.

  The water supply section 30 includes a water supply device 31 and a preheater 35. The water supply unit 31, the low-temperature unit 13, the low-temperature heat exchange unit 22, the high-temperature heat exchange unit 23, the preheater 35, and the mixer 50 are connected by a water supply pipe shown by a solid line in FIG.

  The water supply device 31 supplies water to each part through a water supply pipe. The water supply device 31 supplies water to the low-temperature heat exchange section 22 through the first path W1. The water supply device 31 supplies water to the preheater 35 through the second path W2 and supplies water to the low-temperature heat exchange section 22 through the third path W3. The water supplied to the low temperature section 13 is supplied to the high temperature heat exchange section 23 through the fourth path W4. The second path W2 is connected to the fourth path W4, and the water that has passed through the preheater 35 is supplied to the high-temperature heat exchange unit 23.

  The preheater 35 is, for example, a gas-liquid heat exchanger, and receives waste heat (heat of high-temperature combustion exhaust gas) from the heater 40 to preheat water supplied from the water supply unit 31. The preheater 35 heats, for example, water at room temperature of about 20 ° C. supplied from the water supply unit 31 to 30 ° C. to 40 ° C. In the low-temperature section 13, for example, normal-temperature water of about 20 ° C. supplied from the water supply device 31 is heated from 30 ° C. to 40 ° C.

  The water heated in the low temperature section 13 and the preheater 35 is supplied to the high temperature heat exchange section 23 through the fourth path W4. The high-temperature heat exchange section 23 discharges high-temperature water by heating the water preheated in the preheater 35 and the low-temperature section 13.

  As described above, by preheating the water supplied to the high-temperature heat exchange unit 23 by the low-temperature unit 13 and the preheater 35, the water supply unit 31 is more efficiently used than when water is directly supplied from the water supply unit 31 to the high-temperature heat exchange unit 23. It is possible to heat the water supplied from.

  In addition, the mixer 50 discharges at least one of the cold water and the hot water separately from the mixed water together with the mixed water of the cold water cooled by the low-temperature heat exchange unit 22 and the hot water heated by the high-temperature heat exchange unit 23. Good. With such a configuration, it is possible to supply cold water and hot water separately.

  FIG. 2 is a diagram illustrating a configuration including the control unit 60 of the cold and hot water supply device 100 according to the first embodiment.

  As shown in FIG. 2, the cold / hot water supply device 100 includes a water supply 31, a heater 40, a mixer 50, a temperature sensor 51, and a controller 60.

  The temperature sensor 51 detects the temperature of the hot water discharged from the mixer 50, and transmits a temperature detection result to the control unit 60.

  The control unit 60 controls each unit of the cold / hot water supply device 100 such as the water supply device 31, the heater 40, and the mixer 50. The function of the control unit 60 is realized by, for example, a program or a plurality of circuits that the CPU reads from the ROM and executes in cooperation with the RAM.

  The control unit 60 performs switching of start or stop of water supply to each unit, adjustment of water supply amount, and the like by controlling, for example, an electromagnetic valve provided in the water supply device 31. The control unit 60 switches the start or stop of the heating of the high-temperature unit 12 and adjusts the heating temperature, for example, by controlling the supply amount of the fuel gas to the heater 40 and the ignition device. The control unit 60 adjusts the temperature of the hot water discharged from the mixer 50 by controlling, for example, an electromagnetic valve provided in the mixer 50 based on a result of temperature detection by the temperature sensor 51.

  As described above, the cold / hot water supply device 100 in the first embodiment is set by mixing the cold water cooled by the low temperature heat exchange unit 22 and the hot water heated by the high temperature heat exchange unit 23. Hot water at a different temperature can be supplied.

  According to the cold / hot water supply device 100, the acoustic wave generated by the thermoacoustic phenomenon in the stack 14 becomes a traveling wave, propagates through the thermoacoustic tube 11 formed in a loop, and is repeatedly amplified by the stack 14. For this reason, the energy conversion efficiency in the stack 24 of the heat pump unit 20 is improved.

  Further, by preheating the water to be supplied to the high-temperature heat exchange section 23 by the low-temperature section 13 and the preheater 35, the hot water is supplied more efficiently than in the case where water is directly supplied from the water supply apparatus 31 to the high-temperature heat exchange section 23. It becomes possible.

  Further, the cold / hot water supply device 100 can obtain the cold water cooled by the low-temperature heat exchange unit 22 separately from the hot water. Therefore, the cold / hot water supply device 100 can separately supply cold water and hot water adjusted to the set temperature.

[Second embodiment]
Next, a second embodiment will be described with reference to the drawings. The description of the same components as those of the embodiment described above is omitted.

  FIG. 3 is a diagram illustrating a configuration of a cold / hot water supply device 200 according to the second embodiment.

  In the cold / hot water supply device 200 according to the second embodiment, a fifth path W5, a sixth path W6, a first valve V1, a second valve V2, a third valve V3, and a fourth valve V4 are provided in the water supply unit 30. This is different from the cold / hot water supply device 100 in the first embodiment. Further, the cold / hot water supply device 200 is not provided with the mixer 50 in the first embodiment.

  The fifth route W5 is a bypass route that bypasses the preheater 32 in the second route W2. The sixth route W6 is a drainage route that branches off from the fourth route W4 and drains outside the device.

  The first valve V1 is provided on a fifth path W5 that bypasses the preheater 32. The second valve V2 is provided on a second path W2 leading to the preheater 32. When the first valve V1 is closed and the second valve V2 is opened, the water supplied from the water supply device 31 is preheated through the preheater 32, and the high-temperature heat exchange is performed through the fourth path W4. It is led to the unit 23. Further, when the first valve V1 is in the open state and the second valve V2 is in the closed state, the water supplied from the water supply device 31 bypasses the preheater 32 and passes through the fourth path W4 without being preheated. Then, it is led to the high-temperature heat exchange section 23.

  The third valve V3 is provided on a fourth path W4 that leads from the low-temperature section 13 to the high-temperature heat exchange section 23. The fourth valve V4 is provided in a sixth path W6 that branches off from the fourth path W4. When the third valve V3 is opened and the fourth valve V4 is closed, the water supplied from the water supply device 31 and preheated by the low-temperature section 13 is guided to the high-temperature heat exchange section 23. When the third valve V3 is closed and the fourth valve V4 is opened, the water supplied from the water supply 31 to the low-temperature section 13 through the first path W1 is discharged out of the apparatus.

  FIG. 4 is a diagram illustrating a configuration including a control unit 60 of the cold and hot water supply device 200 according to the second embodiment.

  As shown in FIG. 4, the control unit 60 is connected to the temperature sensor 25, the water supply device 31, the heater 40, the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4. . The temperature sensor 25 detects the temperature of the hot water discharged from the high-temperature heat exchange unit 23 and transmits the temperature detection result to the control unit 60. The first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 are, for example, electromagnetic valves, and are controlled by the control unit 60 to open and close the respective paths.

  Next, a method in which the control unit 60 controls the temperature of hot water from the high-temperature heat exchange unit 23 will be described.

  FIG. 5 is a diagram illustrating high-temperature control of the cold / hot water supply device 200 according to the second embodiment.

  When controlling the temperature of the hot water from the high-temperature heat exchange unit 23 to a high temperature, the control unit 60 closes the first valve V1 and opens the second valve V2 to switch the water supply device 31 to the second path W2. The supplied water is preheated by a preheater 32. In addition, the control unit 60 opens the third valve V3 and closes the fourth valve V4 to heat the water supplied from the water supply unit 31 to the first path W1 and preheated in the low temperature unit 13 to high temperature heat. It leads to the exchange unit 23.

  In this way, by pre-heating the water supplied to the high-temperature heat exchange unit 23 by the low-temperature unit 13 and the pre-heater 32, the temperature of the hot water from the high-temperature heat exchange unit 23 can be increased. In the high-temperature control, for example, water preheated to about 40 ° C. by the low-temperature section 13 and the preheater 32 is heated in the high-temperature heat exchange section 23 and taps at about 80 ° C.

  FIG. 6 is a diagram illustrating the medium temperature control of the cold / hot water supply device 200 according to the second embodiment.

  When controlling the temperature of hot water from the high-temperature heat exchange unit 23 to a medium temperature, the control unit 60 closes the first valve V1 and opens the second valve V2 to switch the water supply 31 to the second path W2. The supplied water is preheated by a preheater 32. Further, the control unit 60 closes the third valve V3 and opens the fourth valve V4, and supplies the water supplied from the water supply device 31 to the first path W1 and preheated in the low temperature unit 13 to the outside of the apparatus. To be discharged.

  In this way, the water preheated by the preheater 32 is supplied to the high-temperature heat exchange section 23, and the water preheated by the low-temperature section 13 is discharged out of the apparatus, so that the temperature of the hot water from the high-temperature heat exchange section 23 becomes medium. be able to. In the medium temperature control, for example, water preheated by the preheater 32 and preheated to about 30 ° is heated in the high temperature heat exchange unit 23 and discharged at about 60 ° C.

  FIG. 7 is a diagram illustrating low-temperature control of the cold / hot water supply device 200 according to the second embodiment.

  When controlling the temperature of the hot water from the high-temperature heat exchange unit 23 to a low temperature, the control unit 60 opens the first valve V1 and closes the second valve V2 to switch from the water supply device 31 to the second path W2. The supplied water is guided to the fifth path W5 to bypass the preheater 32. Further, the control unit 60 closes the third valve V3 and opens the fourth valve V4 to supply water supplied from the water supply device 31 to the first path W1 and preheated in the low-temperature unit 13 to the outside of the apparatus. To be discharged.

  In this way, the water bypassing the preheater 32 is supplied to the high-temperature heat exchange section 23, and the water preheated by the low-temperature section 13 is discharged out of the apparatus, so that the temperature of tap water from the high-temperature heat exchange section 23 is reduced. can do. In the low-temperature control, for example, water of about 20 ° C. supplied from the water supply unit 31 is heated in the high-temperature heat exchange unit 23 and discharged at about 40 ° C.

  As described above, the control unit 60 controls the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 to set the tapping temperature from the high-temperature heat exchange unit 23 to “high temperature”, “ It can be switched to "medium temperature" or "low temperature".

  FIG. 8 is a diagram illustrating a flowchart of a tapping temperature control process according to the second embodiment.

  When hot water is supplied from the cold / hot water supply device 200, the control unit 60 first checks the set temperature set in the cold / hot water supply device 200 in step S101. In the cold / hot water supply device 200, the temperature at which the user taps the hot water is set to one of “high temperature”, “medium temperature”, and “low temperature”. The control unit 60 confirms the set temperature set by the user.

  Next, in step S102, control unit 60 starts high-temperature control regardless of the set temperature. First, by performing the high temperature control, even when the set temperature is “medium temperature” or “low temperature”, the tapping temperature can be set to the set temperature in a shorter time.

  Subsequently, in step S103, control unit 60 checks whether or not the set temperature is “high temperature”. If the set temperature is “high temperature” (step S103: YES), the control unit 60 continues the high temperature control in step S104. In step S105, high-temperature (for example, about 80 ° C.) hot water is discharged from the high-temperature heat exchange unit 23 by the high-temperature control.

  If the set temperature is not “high temperature” (step S103: NO), in step S106, control unit 60 checks whether the set temperature is “medium temperature”. If the set temperature is “medium temperature” (step S106: YES), the process proceeds to step S107.

  In step S107, the control unit 60 confirms whether or not the temperature of the hot water from the high-temperature heat exchange unit 23 has reached a medium temperature (for example, about 60 ° C.) based on the temperature detection result of the temperature sensor 25. The control unit 60 continues the high-temperature control until the temperature of the hot water from the high-temperature heat exchange unit 23 reaches the medium temperature.

  If the hot water temperature from high-temperature heat exchange unit 23 has reached the medium temperature (step S107: YES), control unit 60 switches to medium temperature control in step S108. In step S109, medium-temperature hot water (for example, about 60 ° C.) flows out of the high-temperature heat exchange unit 23 by medium temperature control.

  If the set temperature is not "medium temperature" (step S106), it is determined that the set temperature is "low temperature" and the process proceeds to step S110. In step S110, control unit 60 confirms whether or not the tapping temperature from high-temperature heat exchange unit 23 has reached a low temperature (for example, about 40 ° C.) based on the temperature detection result of temperature sensor 25. The control unit 60 continues the high-temperature control until the hot water temperature from the high-temperature heat exchange unit 23 reaches a low temperature.

  When the hot water temperature from high-temperature heat exchange unit 23 has reached a low temperature (step S110: YES), control unit 60 switches to low-temperature control in step S111. In step S112, low-temperature (eg, about 40 ° C.) hot water flows from the high-temperature heat exchange unit 23 by low-temperature control.

  As described above, the control unit 60 switches the control to one of the high-temperature control, the medium-temperature control, and the low-temperature control based on the set temperature set by the user, thereby changing the tapping temperature from the high-temperature heat exchange unit 23. it can.

  As described above, according to the cold / hot water supply device 200 in the second embodiment, the control unit 60 switches the control, thereby changing the hot water temperature from the high-temperature heat exchange unit 23 to high, medium, and low temperatures. Can be. Further, the cold / hot water supply device 200 can also supply the cold water cooled in the low temperature heat exchange section 22. Therefore, in the cold / hot water supply device 200, it is possible to supply the cooling water and the hot water at the set temperature without using a mixer for mixing the cold water and the hot water.

  As described above, the cold / hot water supply device according to the embodiment has been described, but the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the present invention. For example, if an acoustic wave can be generated in the thermoacoustic tube 11, the configuration of the acoustic wave generator HP1 is not limited to the configuration including the high-temperature section 12, the low-temperature section 13, and the stack 14 illustrated as the embodiment. Further, for example, as long as heat exchange is possible in the heat pump tube 21, the configuration of the heat exchanger HP2 is not limited to the configuration including the low-temperature heat exchange unit 22, the high-temperature heat exchange unit 23, and the stack 24 illustrated as the embodiment. Absent. Further, for example, the first valve V1 as the first opening / closing unit, the second valve V2 as the second opening / closing unit, and the third valve V3 as the third opening / closing unit can open and close each path to switch the water supply path. If it is, each may not be a valve.

DESCRIPTION OF SYMBOLS 10 Acoustic wave generation part 11 Thermoacoustic tube 12 High temperature part 13 Low temperature part 14 Stack 20 Heat pump part 21 Heat pump tube 22 Low temperature heat exchange part 23 High temperature heat exchange part 24 Stack 30 Water supply part 31 Water supply device 35 Preheater 40 Heater 50 Mixer 100, 200 Cold / hot water supply device HP1 Acoustic wave generator HP2 Heat exchanger W1 First path W2 Second path (first preheating path)
W3 Third path W4 Fourth path (second preheating path)
W5 5th route (detour route)
W6 Sixth path V1 First valve (first opening / closing unit)
V2 2nd valve (2nd opening / closing part)
V3 Third valve (third opening / closing part)
V4 4th valve

Claims (3)

A loop-shaped thermoacoustic tube,
An acoustic wave generator that is provided in the thermoacoustic tube and generates an acoustic wave;
A loop-shaped heat pump tube connected to the thermoacoustic tube and guided by the acoustic wave,
A heat exchanger provided in the heat pump tube and performing heat exchange,
A heater for heating the acoustic wave generator,
A water supply device for supplying water to the acoustic wave generator and the heat exchanger,
A preheater for preheating water supplied from the water supply to the heat exchanger with waste heat of the heater,
The acoustic wave generator has a high-temperature portion heated by the heater, and a low-temperature portion cooled by water supplied from the water supply device,
The heat exchanger includes a low-temperature heat exchange unit that cools water supplied from the water supply unit, and a high-temperature heat exchange unit that heats water preheated by the preheater. apparatus. A mixer that mixes the cold water cooled by the low-temperature heat exchange unit and the hot water heated by the high-temperature heat exchange unit,
The cold / hot water supply device according to claim 1, further comprising: a control unit that controls a temperature of the hot water discharged from the mixer by changing a mixing amount of the cold water and the hot water in the mixer. A first preheating path for guiding water supplied from the water supply device to the high-temperature heat exchange section through the preheater;
A bypass path bypassing the preheater in the first preheating path;
A second preheating path for guiding water that has passed through the cooled part to the high-temperature heat exchange part;
A first opening / closing unit that opens / closes the bypass route;
A second opening / closing unit that opens and closes the first preheating path;
A third opening / closing unit that opens and closes the second preheating path;
A control unit that switches the open / close state of the first opening / closing unit, the second opening / closing unit, and the third opening / closing unit to control the temperature of the hot water discharged from the high-temperature heat exchange unit. The cold / hot water supply device according to claim 1.

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