JP2007147153A - Hot-water storage type hot-water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot-water storage type hot-water supply device capable of preventing increase of electric power consumption and increase of noise, and capable of positively preventing freezing of a pipe arrangement for a bath circulation passage. <P>SOLUTION: When it is judged that an outside air temperature T3 is a predetermined temperature or less, a selector valve 50 is put into a first state, unheated bathtub is circulated between a bypass pipe 49 and a bathtub B, and freezing prevention operation is carried out for a predetermined time. After passage of the predetermined time, if a bath temperature T6 is less than a predetermined temperature, the selector valve 50 is changed to a second state, and bathtub water heated by a bath heat exchanger 43 is circulated between the bath heat exchanger 43 and the bathtub B to carry out freezing prevention operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water storage type hot water supply apparatus that can prevent freezing of piping between a hot water storage tank and a bathtub.

Conventional hot water storage hot water supply systems, such as a reheating function for warming the bathtub water filled in the bathtub, and a heat retaining function for keeping the bathtub water filled in the bathtub at a constant temperature, etc. There is a thing equipped with. The reheating function and the heat retaining function are performed by, for example, a circulation system in which a bath circulation path for circulating hot water is provided between the heating means and the bathtub, and the hot water taken out from the bathtub is heated by the heating means and returned to the bathtub. ing. However, when used in a low temperature environment where the temperature drops below freezing point such as in a cold district or in winter, piping used for the bath circulation path may freeze. In order to prevent such freezing, a bypass pipe that bypasses the heating means is provided in the bath circulation path to circulate the hot water in the bathtub (see Patent Document 1).
Japanese Patent Laying-Open No. 2003-50048 (FIG. 1)

  However, in the conventional hot water storage type hot water supply apparatus, when the hot water is circulated through the bypass pipe when used in a low temperature environment, there is a problem that the temperature of the hot water gradually decreases and freezes. Therefore, control for continuously operating the bath pump is conceivable as a countermeasure for this, but there are problems that the noise during the operation of the bath pump lasts for a long time and the power consumption increases. There is also a method of using a heater for preventing freezing in the pipe, but this further increases the power consumption.

  The present invention solves the above-described conventional problems, and provides a hot water storage type hot water supply apparatus that can prevent an increase in power consumption and noise, and can reliably prevent freezing of piping in a bath circuit. Objective.

  The hot water storage type hot water supply apparatus of the present invention includes a hot water storage tank for storing heated hot water, heating means for heating hot water in the hot water storage tank, hot water stored in the hot water storage tank, and a bathtub in the bathtub. A bath comprising a heat exchanger for exchanging heat with water, the heat exchanger, a bath outlet pipe for flowing bathtub water to the heat exchanger, and a bath return pipe for flowing bathtub water that has passed through the heat exchanger to the bathtub A circulation path, temperature detection means for detecting the temperature of bathtub water flowing in the bath circulation path, a bath pump for circulating the bathtub water to the bath circulation path, a switching valve provided in the bath outlet pipe, and one end In a hot water storage hot water supply apparatus comprising a bypass pipe connected to the downstream side of the heat exchanger and the other end connected to the switching valve, the switching valve is operated to pass the bath water from the bath outlet pipe through the bypass pipe And return to the bath return pipe in the first state for a predetermined time When the temperature of the bath water in the bath circuit after the elapse of the predetermined time is less than the predetermined temperature, the switching valve is operated to return the bath water from the bath going pipe to the bath return pipe through the heat exchanger. In the second state, the bath water is circulated through the bath circuit.

  According to the present invention, the bath water is first circulated through the bypass pipe, and then the bath water is circulated through the heat exchanger as necessary, so that the bath circulation path can be reliably prevented from freezing. Therefore, since it is not necessary to use a heater, power consumption can be reduced. Further, since the bath water can be circulated through the heat exchanger, it is possible to prevent the bath pump from driving for a long time and increasing noise.

  In addition, an outside air temperature detecting means for detecting the outside air temperature is provided, and when the outside air temperature detected by the outside air temperature detecting means falls below a predetermined temperature, the bath water is circulated for a predetermined time in the first state, and after a predetermined time has elapsed. When the temperature of the bath water in the bath circulation path is lower than the predetermined temperature, the switching valve is operated to return the bath water to the bath return pipe from the bath return pipe to the bath return pipe in the second state. Is returned to the first state when the temperature of the bath water in the bath circulation path exceeds a predetermined temperature. Thus, even if it is a case where it drive | operates based on external temperature, freezing of a bath circuit can be prevented.

  According to the present invention, increase in power consumption and noise can be prevented, and freezing of piping in the bath circulation path can be reliably prevented.

FIG. 1 is an overall configuration diagram showing a hot water storage type hot water supply apparatus according to the present embodiment, FIG. 2 is a flowchart showing processing at the time of freeze prevention operation, FIG. 3 is an explanatory view of the bypass side freeze prevention operation in this embodiment, and FIG. These are explanatory drawings of the freeze prevention operation by the side of the heat exchanger in this embodiment.
As shown in FIG. 1, a hot water storage type hot water supply apparatus A of the present embodiment includes a heat pump unit (heating means) 1, a hot water storage tank unit 2, a hot water supply control unit 3, and the like. In this embodiment, the hot water taken out from the lower part of the hot water storage tank 21 to be described later is low temperature water (low temperature water; for example, about 5 to 20 ° C.), and the hot water heated by the heat pump unit 1 is high temperature water (high temperature). For example, about 70 to 90 ° C.).

  The heat pump unit 1 includes a compressor 11, a refrigerant-water heat exchanger 12 as a condenser, an expansion valve 13 as a decompressor, and a heat pump circuit 15 including a forced air-cooled evaporator 14. And a heat pump control unit 5 that drives and controls the heat pump circuit 15. In the heat pump circuit 15, for example, carbon dioxide is used as a refrigerant to constitute a supercritical heat pump cycle. Further, since carbon dioxide is used as the refrigerant, it is possible to boil low temperature water to a high temperature of about 90 ° C. without an electric heater.

  In the heat pump unit 1, a heat pump return pipe (outflow pipe) 25 extending from the hot water storage tank unit 2 described later is connected to one end of a flow path provided separately from the heat pump circuit 15 of the refrigerant-water heat exchanger 12. The heat pump return pipe 25 is provided with a heat exchanger inlet temperature sensor T1. The other end of the refrigerant-water heat exchanger 12 is connected to a heat pump forward pipe (inflow pipe) 26 extending from the hot water storage tank unit 2 described later. The heat pump outlet pipe 26 is provided with a heat exchanger outlet temperature sensor T2. It has been. Further, the heat pump unit 1 is provided with an outside air temperature sensor T3 for detecting the temperature of the outside air.

  The refrigerant-water heat exchanger 12 employs a counter flow system in which the refrigerant and heated water (low temperature water) face each other, and the refrigerant is supercritical during heat exchange by the supercritical heat pump cycle. Since it is condensed in the state, the water to be heated can be efficiently heated to a high temperature. Further, the expansion valve described above so that the temperature difference between the temperature of the heat exchanger inlet temperature sensor T1 on the inlet side of the refrigerant-water heat exchanger 12 and the temperature of the heat exchanger outlet temperature sensor T2 on the outlet side becomes constant. 13 or by controlling the compressor 11, the COP (energy consumption efficiency) is reduced when the inlet temperature of the refrigerant-water heat exchanger 12 of the water to be heated (low temperature water) is a low temperature of about 5 to 20 ° C. It is possible to heat the water to be heated with a high efficiency of 3.0 or more.

  The hot water storage tank unit 2 has a hot water storage tank 21 that is elongated in the vertical direction (vertical direction). The hot water storage pipe 21 communicates with the interior of the hot water storage tank 21 at the upper part thereof and the hot water supply pipe 24 at the lower part thereof. It is connected. The water supply pipe 24 is connected to a water pipe so that water (tap water) is supplied. Further, the water supply pipe 24 is provided with a pressure reducing valve 36 for reducing the water supply pressure from the water pipe to a predetermined pressure, a water supply temperature sensor 37 for detecting the temperature of the water flowing through the water supply pipe 24, and the like.

  The hot water storage tank 21 is provided with a hot water storage temperature sensor T4 including a plurality of temperature sensors arranged in the vertical direction. The hot water storage temperature sensor T4 detects the temperature distribution in the vertical direction in the hot water storage tank 21 and detects how much heat remains in the hot water storage tank 21.

  Further, the hot water storage tank 21 is connected so that the end of the heat pump return pipe 25 is communicated with the inside of the hot water storage tank 21 at the lower part and the end of the heat pump forward pipe 26 is communicated with the upper part. In addition, a circulation pump 27 is provided in the heat pump return pipe 25, and the water to be heated (low temperature water) in the hot water storage tank 21 is exchanged between the refrigerant and the water through the heat pump return pipe 25 by the driving force of the circulation pump 27. It is sent to the vessel 12 and sent out from the refrigerant-water heat exchanger 12 via the heat pump forward pipe 26. In addition, in this embodiment, although the circulation pump 27 is provided in the heat pump unit 1 side, it is not limited to this, You may provide in the hot water storage tank unit 2 side.

  The hot water discharge pipe 23 is connected to a branch pipe 30 branched from the water supply pipe 24 via a hot water supply mixing valve 31. This hot-water supply mixing valve 31 is a valve that mixes high-temperature water taken out from the hot-water supply pipe 23 and water (tap water) from the branch pipe 30, and has a hot-water supply set temperature set by the user with the remote controller 4 described later. Thus, the mixing ratio can be controlled. A hot water supply pipe 32 is connected downstream of the hot water supply mixing valve 31. A hot water supply temperature sensor T 5 for detecting the temperature of the hot water mixed by the hot water supply mixing valve 31 and a hot water supply for detecting the flow rate of the hot water are connected to the hot water supply pipe 32. A flow sensor 34 is provided. In addition, a hot water tap 35 is provided at the end of the hot water supply pipe 32, and this hot water tap 35 is provided in a kitchen, a bathroom, a bathroom and the like. The hot water discharge pipe 23 is provided with a pressure relief valve 38 for releasing the pressure of the hot water storage tank 21.

  In addition, the hot water storage type hot water supply apparatus A of the present embodiment includes a bathtub B. In the bathtub B, one end of the bath return pipe 41 and one end of the bath return pipe 42 are connected to each other. In the hot water storage tank 21, a bath heat exchanger 43 made of a stainless steel serpentine tube for heating the hot water stored in the bathtub B is provided, and a bath pipe 41 is provided at the entrance of the bath heat exchanger 43. The other end of the return pipe 42 is connected to the outlet. In addition, this bath heat exchanger 43 is arrange | positioned so that it may be located near the upper part where the high temperature water of the hot water storage tank 21 is accumulate | stored, for example.

  The bath tube 41 includes a bath temperature sensor (temperature detection means) T6 for detecting the temperature of the bath water flowing from the bath B to the bath heat exchanger 43, and bath water between the bath B and the bath heat exchanger 43. A bath pump 48 for circulating the gas is provided. The bath return pipe 42 is provided with a bath return temperature sensor T7 for detecting the temperature of bath water flowing from the bath heat exchanger 43 to the bath B. By operating the bath pump 48, the bath water stored in the bath B is sent to the bath heat exchanger 43, and the bath water is heated by the bath heat exchanger 43, so that the bath water in the bath B is heated. Insulation or chasing is done. The bath circulation pipe according to claim 1 is constituted by the bathing pipe 41 and the bath return pipe 42.

  Further, an end portion of a bypass pipe 49 is connected to each of the flow forward pipe 41 and the wide return pipe 42. The bypass pipe 49 is a pipe for bypassing the bath heat exchanger 43, and is provided near the bath heat exchanger 43. Moreover, the connection part of the bypass pipe 49 and the throat pipe 41 has the 1st state which circulates a bathtub between the bathtub B so that the warm water of the bathtub B may pass the bypass pipe 49, and the bathtub B and the bath heat A switching valve 50 that can be switched to the second state in which the bath water is circulated with the exchanger 43 is provided. The switching valve 50 is configured by, for example, an electromagnetic three-way valve, and is switched between a first state and a second state based on an output signal from a hot water supply control unit 3 to be described later.

  Further, the bath pipe 41 is connected to the hot water supply pipe 32 through a hot water filling pipe 44. The hot water filling pipe 44 includes a hot water filling valve 45 that opens when hot water filling to the bathtub B starts and closes when the hot water filling stops, a bath flow counter 46 that counts the amount of hot water filling the bathtub B, and a bathtub A check valve 47 for preventing the bathtub water in B from flowing back to the hot water supply pipe 32 is provided. Thus, when filling the bathtub B, the hot water valve 45 is opened so that the hot water set at a desired bath temperature from the remote controller 4 to be described later is supplied from the hot water supply mixing valve 31 to the hot water pipe 44 and the bath. It is supplied to the bathtub B through the forward pipe 41.

  The hot water storage tank unit 2 is provided with a hot water supply control unit 3. The hot water supply control unit 3 includes a CPU (Central Processing Unit), a storage unit, an input / output unit, and the like, and the rotation of the motors of the circulation pump 27 and the bath pump 48 based on information from various temperature sensors T1 to T7. It controls speed, flow path switching of the switching valve 50, mixing ratio of the hot water supply mixing valve 31, opening and closing of the hot water filling valve 45, and the like.

  The remote controller 4 includes a hot water supply temperature setting switch 4a for setting the hot water supply temperature, a bath temperature setting switch 4b for setting the bath temperature, and a hot water amount setting switch provided in the remote controller 4 for hot water having the set bath temperature. The bath automatic switch 4c is used to fill with the amount of hot water set in (not shown) and keep warm for a predetermined time, the reheating switch 4d for reheating, and the hot water in the hot water storage tank 21 in the daytime period. In addition, a heating switch 4e for boiling a certain amount, a display unit 4f comprising a liquid crystal display panel for displaying the hot water supply temperature, the amount of remaining hot water in the hot water storage tank 21 and the like, a speaker for buzzer sound and voice guidance (not shown) A remote control unit (not shown) for comprehensively controlling them is provided. The remote controller 4 is connected to the hot water supply control unit 3 by wire or wirelessly, and information set by the remote control 4 is sent to the hot water supply control unit 3.

Next, operation control of the hot water storage type hot water supply apparatus A of the present embodiment will be described.
First, the boiling operation of the hot water storage type hot water supply apparatus A will be described. When the hot water supply control unit 3 detects that the amount of heat necessary for the next day does not remain in the hot water storage tank 21 based on the hot water storage temperature sensor T4 in the late-night electricity time zone in which the electricity rate is set to be cheap, the heat pump control A boiling start command is issued to the unit 5. The heat pump control unit 5 provided in the heat pump unit 1 that has received this command starts driving the circulation pump 27 after starting the compressor 11. Subsequently, low temperature water of about 5 to 20 ° C. is taken out from the lower part of the hot water storage tank 21, and this taken out low temperature water is sent to the refrigerant-water heat exchanger 12 through the heat pump return pipe 25 to be 70 to 90. Heated to a high temperature of about ℃. The high-temperature water sent out from the refrigerant-water heat exchanger 12 to the heat pump forward pipe 26 is put into the upper part of the hot water storage tank 21. Incidentally, in the hot water storage tank 21, for example, high temperature water is stored in the upper part and low temperature water is stored in the lower part. This is caused by a difference in specific gravity due to the temperature difference, forming a temperature boundary layer and a high temperature with a low specific gravity. Since water is located in the upper part and low-temperature water having a higher specific gravity is located in the lower part, they do not mix with each other. Thereafter, when the hot water supply control unit 3 detects that the necessary amount of heat has been stored based on the temperature distribution information of the hot water storage tank 21 obtained from the hot water storage temperature sensor T4, it issues a boiling stop command to the heat pump control unit 5. Then, the compressor 11 is stopped and the circulation pump 27 is stopped, and the boiling operation is finished.

  Further, during the hot water supply operation of the hot water storage type hot water supply apparatus A, when the user opens the hot water tap 35, the hot water in the hot water storage tank 21 is directed toward the hot water discharge pipe 23 by the supply water pressure (back pressure) from the water supply pipe 24. Extruded. High-temperature water of about 70 to 90 ° C. pushed out from the hot water storage tank 21 and water supplied from the water supply pipe 24 through the branch pipe 30 become the hot water supply temperature set by the user with the remote controller 4 in the hot water supply mixing valve 31. After being mixed as described above, hot water is supplied from the hot water tap 35 through the hot water supply pipe 32.

Next, control during freezing prevention operation of the hot water storage type hot water supply apparatus A of the present embodiment will be described with reference to FIGS. 2 to 4 (refer to FIG. 1 as appropriate).
As shown in FIG. 2, the hot water supply control unit 3 (see FIG. 1) is based on the temperature information obtained from the outside air temperature sensor T3 (see FIG. 1). Is determined to be 5 ° C. or less (step S100). If the outside air temperature (T3) is not 5 ° C. or lower in step S100 (No), it is determined that the bath circulation path composed of the forward and backward pipes 41 and 42 is not frozen, and the process of step S100 is repeated. When it is determined that the outside air temperature (T3) is 5 ° C. or less (Yes), it is determined that there is a possibility that the bath circulation path composed of the furrow pipe 41 and the furrow return pipe 42 may be frozen, thereby preventing freezing. The operation is started, the switching valve 50 is switched to the first state (bypass side) (S101), and the bath pump 48 is turned on (S102). Thereby, as shown by a thick line in FIG. 3, the bathtub water taken out from the bathtub B is circulated so as to return to the bathtub B through the bath pipe 41, the bypass pipe 49 and the bath return pipe 42. In this way, the switching valve 50 is set to the first state, and the bypass pipe 49 is circulated between the bypass pipe 49 and the bathtub B by circulating the bathtub water (hot water) stretched on the bathtub B. It is possible to prevent freezing of the bath circulation path composed of the passage pipe 41 and the passage return pipe. In step S103, it is determined whether or not a predetermined time has elapsed since the bath water was circulated in the bath circulation path. If it is determined that the predetermined time has elapsed (Yes), the process of step S104 is performed. Transition. The predetermined time in step S103 is set within a range where there is no possibility of freezing according to the outside air temperature (T3), but can be changed as appropriate, for example, about 10 minutes.

  In step S104, the hot water supply control unit 3 determines whether or not the bath temperature is less than 5 ° C. based on the temperature information obtained from the bath temperature sensor T6. If it is determined in step S104 that the bath temperature (denoted as T6 in the flow of FIG. 2) is less than 5 ° C. (Yes), the switching valve 50 is set to the second state and the hot water is bathed. It switches so that it may pass through the exchanger 43 (step S105). Accordingly, as shown by a thick line in FIG. 4, the bath water introduced from the bath B to the bath heat exchanger 43 through the bath pipe 41 is heated hot water (hot water) accumulated in the hot water storage tank 21. After being heated by the circulatory circuit, it is circulated so as to return to the bathtub B through the bath return pipe 42. Thus, since the bath water heated by the bath heat exchanger 43 is circulated through the bath circulation path composed of the bath tube 41 and the bath return tube 42, the bath tube 41 and the bath return tube 42 are formed. The freezing of the bath circuit can be reliably prevented.

  In step S106, it is determined whether the bath temperature (T6) has exceeded 10 ° C. When it is determined in step S106 that the bath temperature (T6) does not exceed 10 ° C. (No), the process of step S106 is repeated, and the bath temperature (T6) is determined to exceed 10 ° C. (Yes), the bath pump 48 is turned off (step S107), and the freeze prevention operation is terminated.

  On the other hand, if it is determined in step S104 that the bath temperature (T6) is not less than 5 ° C. (No), the bath pump 48 is turned off and the freeze prevention operation is performed without switching the switching valve 50 to the second state. Is finished (step S107). After the freeze prevention operation is completed, the processes after step S100 are repeated.

  As described above, in the hot water storage type hot water supply apparatus A of the present embodiment, the freezing pipe 41 and the free return pipe 42 can be reliably prevented from freezing. Moreover, since the freezing prevention is aimed at by circulating the hot water stretched in the bathtub B which is not heated with the bath heat exchanger 43 first, the heat in the hot water storage tank 21 is wasted by the bath heat exchanger 43. This eliminates the need for re-boiling operation due to a decrease in the amount of heat in the hot water storage tank 21 and is excellent in terms of economy. Further, since it is not necessary to provide a pipe heater in the forward pipe 41 and the long return pipe 42, an increase in power consumption can be prevented, and the assembly process can be simplified and the cost can be reduced. When the switching valve 50 is switched to the first state and unheated bath water is circulated to perform the freeze prevention operation, the bath pump 48 can be turned off after a predetermined time has passed. Is switched to the second state and the bath water heated by the bath heat exchanger 43 is circulated to perform the freeze-preventing operation, the bath pump when the bath temperature (T6) rises to a predetermined temperature. 48 can be turned off, that is, in any case, since the bath pump 48 can be turned off early, it is possible to prevent the bath pump 48 from driving for a long time at midnight and increasing noise.

  In addition, when hot water is not stretched in the bathtub B, since warm water does not exist in the bath circulation path of the bathing pipe 41 and the bathing return pipe 42, the bathing pipe 41 and the bathing return pipe 42 do not freeze.

  In the present embodiment, the temperature sensor T6 is used as the temperature detection means for detecting the temperature of the bath, but the present invention is not limited to this, and the temperature may be determined using the temperature return temperature sensor T7.

It is a whole lineblock diagram showing the hot water storage type hot-water supply device of this embodiment. It is a flowchart which shows the process in a freeze prevention driving | operation. It is explanatory drawing of the antifreezing operation which passes along the bypass pipe in this embodiment. It is explanatory drawing of the freezing prevention driving | operation which passes along the heat exchanger in this embodiment.

Explanation of symbols

1 Heat pump unit (heating means)
2 Hot water storage tank unit 21 Hot water storage tank 41 Bathing pipe (bath circuit)
42 bath return pipe (bath circuit)
43 bath heat exchanger (heat exchanger)
49 Bypass pipe 50 Switching valve A Hot water storage type hot water supply device T3 Outside temperature sensor (outside temperature detecting means)
T6 bathing temperature sensor (temperature detection means)

Claims (2)

A hot water storage tank for storing heated hot water,
Heating means for heating the hot water in the hot water storage tank;
A heat exchanger provided in the hot water storage tank for exchanging heat between the hot water stored in the hot water and the bathtub water in the bathtub;
A bath circuit comprising the heat exchanger, a bath outlet pipe for flowing bathtub water to the heat exchanger, and a bath return pipe for flowing bathtub water that has passed through the heat exchanger to the bathtub;
Temperature detecting means for detecting the temperature of the bathtub water flowing in the bath circulation path;
A bath pump that circulates bathtub water in the bath circuit,
A switching valve provided in the bath outlet pipe;
In a hot water storage type hot water supply apparatus provided with a bypass pipe having one end connected to the downstream side of the heat exchanger and the other end connected to the switching valve,
The bathtub water is circulated for a predetermined time in the first state in which the switching valve is operated to return the bathtub water from the bath outlet pipe to the bath return pipe through the bypass pipe, and the bath water in the bath circulation path after the predetermined time has elapsed. When the temperature of the bath is lower than the predetermined temperature, the switching valve is operated to circulate the bath water in the bath circulation path in the second state in which the bath water is returned from the bath going pipe through the heat exchanger to the bath return pipe. Hot water storage type hot water supply device characterized by   An outside air temperature detecting means for detecting the outside air temperature is provided, and when the outside air temperature detected by the outside air temperature detecting means falls below a predetermined temperature, the bath water is circulated for a predetermined time in the first state, and the bath after the predetermined time has passed. When the temperature of the bath water in the circulation path is lower than the predetermined temperature, the switching valve is operated to bathe the bath water in the second state in which the bath water is returned from the bath outlet pipe to the bath return pipe through the heat exchanger. The hot water storage type hot water supply apparatus according to claim 1, wherein the hot water storage type hot water supply apparatus is returned to the first state when the temperature of the bath water in the bath circulation path becomes equal to or higher than a predetermined temperature.

Images