JP4955375B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type hot water supply apparatus that keeps hot water in a bathtub using hot water storage hot water in a hot water storage tank.

Conventionally, in this type of electric water heater and heat pump hot water storage type hot water supply device, if there is a reheating command, the temperature of the hot water stored in the hot water storage tank is detected, and if this temperature is higher than the predetermined temperature, the reheating operation is performed. If the temperature is lower than the predetermined temperature, the reheating operation is not performed, and hot water in the hot water storage tank is poured into the bathtub.
JP 2003-50048 A

  However, in this conventional one, when the bath water drops below the bath set temperature at regular intervals over a predetermined time, when performing a heat insulation operation to maintain the bath water at the bath set temperature in the same way as reheating, If the hot water storage temperature of the hot water storage tank is higher than the specified temperature, the temperature is maintained. Therefore, even when the temperature of the bath water is high and the temperature difference from the hot water storage temperature of the hot water tank is small, the hot water storage temperature is predetermined. If the temperature is higher than the temperature, the heat insulation is continued, and it takes a long time to raise the bath water to the temperature desired by the user, and the heat insulation operation is continued indefinitely. There was a problem that the temperature was lowered by exchanging heat with the bath water, and the efficiency was lowered due to an increase in the amount of hot water storage that could not be used as a heat source for heat insulation and was difficult to use for hot water supply.

Therefore, in order to solve the above-described problems, the present invention is particularly provided with a hot water storage tank for storing hot water heated by the heating means, a bath circulation circuit for circulating hot water in the bathtub, and in the middle of the bath circulation circuit. In the operation of the bath heat exchanger that heats the bath water with hot water stored in the hot water storage tank and the hot water supply control unit that heats the hot water in the hot water storage tank by the heating means, an entrusted mode that places importance on not running out of hot water, There is a saving mode that emphasizes that there is no cost of electricity, and in the case of selecting one of them, when performing a heat insulation operation in which the bath water is circulated through the bath heat exchanger and the temperature is kept constant, continued maintenance operation in selection of the Random mode up operation, in the saving mode selection is obtained by a maintenance operation time shortened to so that.

According to the present invention, since the heat insulation specification of the bath is automatically determined according to the boiling mode selected by the user, there is a sufficient amount of heat in the hot water storage tank in the mode that places importance on not running out of hot water, If there is a shortage during heat insulation, boiling is automatically increased, so normal heat insulation operation using a bath heat exchanger is performed, and in the saving mode that emphasizes that there is no cost for electricity, because sufficient heat without marginal state is predicted, the continuation of the maintenance operation is judged to force, the maintenance operation time by shortening, waste heat of the hot water storage tank maintenance operation is continued for a long time to Therefore, it is possible to obtain an efficient operation while saving and saving.

Next, an embodiment of the present invention will be described with reference to the drawings.
This hot water storage type hot water supply device boils and stores hot water in the midnight hours when the unit price of contracted power by time is low, and uses the hot water stored for hot water supply. 1 is a hot water storage tank 2 for storing hot water. 3 is a heat pump unit as a heating means for heating hot water in the hot water storage tank, 4 is a hot water tap provided in a kitchen or a washroom, etc. 5 is a remote control for remotely operating the hot water storage type hot water supply device , 6 is a bathtub.

  The hot water storage tank 2 of the hot water storage tank unit 1 has a hot water discharge pipe 7 connected to the upper end, a water supply pipe 8 connected to the lower end, a heat pump forward pipe 9 constituting a heat pump circulation circuit in the lower part, and a heat pump circulation circuit in the upper part. To the heat pump return pipe 10, the hot water in the hot water storage tank 2 taken out from the heat pump forward pipe 9 is boiled by the heat pump unit 3, returned to the hot water storage tank 2 from the heat pump return pipe 10, and stored in the hot water supply pipe 8. The hot water in the hot water storage tank 2 is pushed up by the water supply from the hot water, and the hot water in the upper part of the hot water storage tank 2 is pushed out from the hot water discharge pipe 7 to be supplied with hot water.

  The heat pump unit 3 includes a compressor 11, a refrigerant-water heat exchanger 12 as a condenser, an electronic expansion valve 13, a forced air-cooled evaporator 14, and hot water in the hot water storage tank 2. A heat pump circulation pump 16 that circulates to the refrigerant-water heat exchanger 12 through the heat pump forward pipe 9 and the heat pump return pipe 10 and a heat pump control unit 17 that controls driving thereof are provided in the heat pump circuit 15. Is one in which carbon dioxide is used as a refrigerant to constitute a supercritical heat pump cycle. Since carbon dioxide is used as the refrigerant, low-temperature water can be boiled up to a high temperature of about 90 ° C. without an electric heater.

  Here, the refrigerant-water heat exchanger 12 employs a counter flow system in which the refrigerant and hot water in the hot water storage tank 2 that is heated water are opposed to each other. In the supercritical heat pump cycle, the refrigerant is exchanged during heat exchange. Since it is condensed in the supercritical state, the heated water can be efficiently heated to a high temperature so that the temperature difference between the refrigerant-water heat exchanger 12 inlet temperature and the refrigerant outlet temperature is constant. Further, by controlling the electronic expansion valve 12 or the compressor 11, the water to be heated can be heated in a state where the COP (energy consumption efficiency) is very good.

  18 is a bath heat exchanger composed of a stainless steel snake pipe for heating the hot water in the bathtub 6, and is disposed at the upper part in the hot water storage tank 2. The bath heat exchanger 18 includes a bath outlet pipe 19 and A bath circulation circuit 22 comprising a bath return pipe 21 equipped with a bath circulation pump 20 is connected so that hot water in the bathtub 6 can be circulated, and the hot water in the bathtub 6 is heated by the high-temperature water in the hot water storage tank 2 to keep it warm. Reaping is done.

  A bath return temperature sensor 23 detects the temperature of the bath water flowing into the bath heat exchanger 18 through the bath return pipe 21, and 24 flows out of the bath heat exchanger 18 to the bath 6 through the bath outlet pipe 19. It is a bath temperature sensor for detecting the temperature of flowing bathtub water.

  Reference numeral 25 denotes a hot water mixing valve composed of an electric mixing valve for mixing hot water from the hot water discharge pipe 7 and low temperature water from the water supply bypass pipe 26 branched from the water supply pipe 9, and hot water supply provided in the hot water supply pipe 27 downstream thereof. The mixing ratio is controlled so that the hot water temperature detected by the temperature sensor 28 becomes the hot water supply set temperature set by the user using the remote controller 5.

  Reference numeral 29 denotes a hot water filling pipe branched from the hot water supply pipe 27 and communicated with the bath return pipe 21. The hot water filling pipe 29 includes a hot water filling valve 30 for starting / stopping hot water filling to the bathtub 6, and a bathtub 6. A bath flow counter 31 that counts the amount of hot water filled in and a check valve 32 that prevents the bath water from flowing back to the hot water supply pipe 27 are provided, and the hot water in the hot water storage tank 2 is directly supplied to the bath 6. The hot water filling pipe 29 is also used when pouring hot water and chasing.

  A plurality of hot water storage temperature sensors 33 are arranged in the vertical direction of the hot water storage tank 2. In this embodiment, five hot water storage temperature sensors are arranged and are called 33 a, 33 b, 33 c, 33 d, 33 e from the top. Is used to detect how much heat is left in the hot water storage tank 2 and to detect the temperature distribution in the vertical direction in the hot water storage tank 2.

  The remote controller 5 is provided with a hot water supply temperature setting switch 34 for setting a hot water supply set temperature and a bath temperature setting switch 35 for setting a bath set temperature, respectively. An automatic bath switch 36 that fills the hot water by the amount of hot water set by a hot water amount setting switch (not shown) and keeps it warm for a predetermined time, and a reheating switch 37 that replenishes the bath water are provided.

  Reference numeral 38 denotes a hot water supply control unit which constitutes a control unit including a microcomputer which receives inputs from the respective sensors in the hot water storage tank unit 1 and controls the driving of each actuator and also has a timer function during a heat insulation operation. The remote controller 5 is connected to the hot water supply control unit 38 by wireless or wired so that the user can set an arbitrary hot water supply set temperature and bath set temperature, and the bath automatic switch 36 and the reheating switch 37 can be simultaneously set. When it is pressed for more than 5 seconds, it enters the boiling mode setting of hot water in the hot water tank 2 by the heat pump unit 3, and when the control is focused on not running out of hot water anyway, the amount of heat in the hot water tank 2 is monitored and the hot water is about to run out The hot water supply temperature setting switch 34 selects either the entrusted mode that makes the heater run even in the daytime when the electricity bill is high, or the saving mode that keeps the heater running as much as possible with emphasis on not taking the electricity bill. It is determined by pressing the automatic switch 36, and when it is not set, the auto mode is automatically set by default. That.

  39 is an overpressure relief valve for releasing the overpressure of the hot water storage tank 2, 40 is a pressure reducing valve for reducing the pressure of the water supply, 41 is a hot water supply flow rate counter for counting the amount of hot water supplied, and 42 is a water supply temperature for detecting the temperature of the water supply. It is a sensor.

Next, the operation of this embodiment will be described.
First, when the hot water storage temperature sensor 39 detects that the necessary amount of heat does not remain in the hot water storage tank 2 in the midnight power time zone, the hot water supply control unit 38 issues a boiling start command to the heat pump control unit 17. To emit. Upon receiving the command, the heat pump control unit 17 starts driving the heat pump after starting the compressor 11, and cools the low temperature water of about 5 to 20 ° C. taken out from the heat pump forward pipe 9 connected to the lower part of the hot water storage tank 2 as a refrigerant. -Heated to a high temperature of about 70 to 90 ° C by the water heat exchanger 12, returned to the hot water storage tank 2 from the heat pump return pipe 10 connected to the upper part of the hot water storage tank 2, and sequentially stacked from the upper part of the hot water storage tank 2 Store hot water. When the hot water storage temperature sensor 33 detects that the necessary amount of heat has been stored, the hot water supply control unit 38 issues a boiling stop command to the heat pump control unit 17, and the heat pump control unit 17 stops the compressor 11 and heat pump circulation. The pump 16 is also stopped to end the boiling operation.

  In addition, when the heating mode is the entrusted mode, the hot water supply control unit 38 calculates the required boiling temperature based on the amount of hot water used in the past week and the amount of hot water used at 17:00 to 23:00. The heat pump unit 3 is automatically driven during the daytime to increase the amount of water that is deficient, and the heater is heated at the low-power of the electricity bill in the saving mode, and it is automatically increased during the daytime. Is a mode that is not performed.

  Next, the hot water supply operation will be described. When the hot water tap 4 is opened, the water supplied from the water supply pipe 8 flows into the hot water storage tank 2. Then, the hot water stored in the hot water storage tank 2 flows into the hot water supply mixing valve 25 through the hot water discharge pipe 7 and is mixed with the low temperature water from the hot water supply bypass pipe 26, and the hot water control section 38 sets the mixing ratio of the hot water supply mixing valve 28. The adjusted hot water at the hot water supply set temperature is supplied from the hot water tap 4. Then, the hot water supply is completed by closing the hot water tap 4.

  Next, the hot water filling operation to the bathtub 6 will be described. When the bath automatic switch 36 of the remote controller 5 is operated, the hot water supply control unit 38 opens the hot water filling valve 30. Then, hot water adjusted to the bath set temperature by the hot water supply mixing valve 28 is filled from the hot water filling pipe 29 to the bathtub 6 through the bath return pipe 21, and a bath flow rate counter 31 provided in the middle of the hot water filling pipe 29 is predetermined. When the amount of hot water filling is counted, the hot water supply control unit 38 closes the hot water filling valve 30 and ends the hot water filling operation.

  Next, after the hot water filling operation, the warming operation is automatically started for a predetermined time, here, 4 hours, and the bath circulation pump 20 is driven once every 30 minutes, and the bath return temperature sensor 24 detects the bath water temperature. If the temperature is lower by 2 to 3 ° C. than the set temperature, a warm-up operation is performed in which the bath water is returned to the bath set temperature by the reheating operation using the bath heat exchanger 18 and the bath circulation circuit 22. As shown in the flowchart of FIG. 2, first, in step 43, it is determined whether the boiling mode is the entrusted mode. If YES, the process proceeds to step 44 to perform the above-described normal heat insulation operation. If the boiling mode is the saving mode, step In step 43, the process proceeds to step 45, where the warming operation is prohibited, and the fact is displayed on the remote controller 5 or the like to notify the user.

  In this way, since the specification of the heat insulation operation is automatically determined according to the boiling mode, it is determined that there is a sufficient amount of heat in the hot water storage tank 2 in the entrusted mode that places importance on not running out of hot water, and the heat is being kept. If the amount of water is insufficient, the operation of reheating is automatically performed, so that the normal heat insulation operation using the bath heat exchanger 18 is performed. Since there is not enough heat in the interior, it is predicted that the state will be barely heated, and even if the amount of heat is insufficient, it will not be heated up, so by prohibiting the heat insulation operation to preserve the heat quantity, the heat insulation operation will continue for a long time or hot water supply However, there is no low-temperature hot water that cannot be used, and efficient operation can be performed.

  Next, a flow chart of another embodiment shown in FIG. 3 will be described. Two or more boiling modes are set, and in the saving mode, the boiling temperature is 80 ° C. to 90 ° C. If you select from “standard” of 60 ° C to 90 ° C and “moderate” with a boiling temperature of 65 ° C, it will be decided in step 46 whether it is “hot water” in the saving mode. If YES, the process proceeds to step 47, and the normal heat insulation operation is performed, but the heat insulation time is reduced from 4 hours to 2 hours. In step 44, NO is judged as “standard” or “moderate”. In step 45, the heat insulation operation is prohibited.

  This makes it possible to select a boiling mode with finer texture and to perform a heat insulation operation according to this mode, and to obtain a good heat insulation operation with good usability.

The schematic block diagram of the hot water storage type hot-water supply apparatus which shows one Embodiment of this invention. The flowchart explaining the heat retention driving | operation of one Embodiment. The flowchart explaining the heat retention driving | operation of other embodiment.

Explanation of symbols

2 Hot water storage tank 3 Heat pump unit (heating means)
6 Bath 18 Bath Heat Exchanger 22 Bath Circulation Circuit 23 Hot Water Supply Control Unit 29 Hot Water Pipe 33 Hot Water Storage Temperature Sensor

Claims (1)

A hot water storage tank for storing hot water heated by the heating means, a bath circulation circuit for circulating hot water in the bathtub, and a bath heat exchanger provided in the middle of the bath circulation circuit for heating the bathtub water with hot water stored in the hot water storage tank And, in the operation of the hot water supply controller that boils the hot water in the hot water storage tank by the heating means, there are provided an entrusted mode that emphasizes not to run out of hot water and a saving mode that emphasizes that no electricity bill is charged, In the selection, when performing the heat insulation operation in which the bath water is circulated to the bath heat exchanger to keep the temperature constant, the heat insulation operation is continued in the selection of the entrusted mode in the boiling operation, hot water storage type water heater, characterized in that you shorten the maintenance operation time is selected.

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