JP2006308124A - Storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage type water heater capable of preventing elongation of a waiting time to reheating because of long additional heating time. <P>SOLUTION: This storage type water heater comprises a storage tank 2 for storing hot water heated by a heating means 3, a bath circulation circuit 22 connected with a bathtub 6, a bath circulation pump 20 circulating hot water in the bathtub 6 to the bath circulation circuit 22, and a bath heat exchanger 18 exchanging heat between the hot water in the bathtub 6 circulated in the bath circulation circuit 22 and the hot water in the storage tank 2, and the bath is kept warm or reheated by heat exchange with the hot water in the storage tank 2 by the bath heat exchanger 18. As the bath is kept warm or reheated under a condition that it is instructed by switching operation of a remote controller 5, and a heat quantity securing means 41 is mounted to perform the additional heating operation by the heating means 3 when the heat quantity in the storage tank 2 is reduced and the bath can not be kept warm or reheated, the demand by a user can be surely fulfilled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water storage type hot water supply apparatus that uses hot water stored in a hot water storage tank to replenish hot water in a bathtub.

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 was lower than a predetermined temperature, the boiling operation was increased and then the chasing operation was performed. (For example, see Patent Document 1)
Japanese Patent No. 3632653

  By the way, with this conventional one, it takes a long time to increase the boiling time, and during this time the user has to wait, and it is necessary to interrupt the bathing once during bathing, which is extremely inconvenient and problematic. Moreover, in order to prevent this, if the water is heated frequently, the electricity cost is increased, the economic efficiency is poor, and the efficiency is lowered.

  Therefore, in order to solve the above-described problems, the present invention is configured to circulate the hot water storage tank for storing hot water heated by the heating means, the bath circulation circuit connected to the bathtub, and the hot water in the bathtub to the bath circulation circuit. And a bath heat exchanger for exchanging the hot water in the bathtub circulating in the bath circulation circuit with the hot water in the hot water storage tank, and the bath heat exchanger exchanges heat with the hot water in the hot water storage tank. In the heating and reheating, the heating target temperature is varied according to the remaining hot water temperature of the bathtub during the heating increase operation with the amount of heat in the hot water storage tank decreasing.

  According to the present invention, if the remaining hot water temperature in the bathtub is high, the temperature difference from the bath setting temperature is small, and the amount of heat necessary for reheating is reduced accordingly, so the boiling time is shortened and the time until reheating is reduced. It is shortened and extremely easy to use. Further, unnecessary boiling is prevented, a necessary amount of heat is surely secured, and an economical and efficient operation can be performed.

Next, a first embodiment of the present invention will be described with reference to the drawings.
In this hot water storage type hot water supply apparatus, hot water is boiled and stored in the midnight hours when the unit price of contracted power by time zone is low, and the hot water stored in the hot water is used 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, an outgoing pipe 9 constituting a heat pump circulation circuit at the lower portion, and a heat pump circulation circuit at the upper end. Connected to the return pipe 10, the hot water in the hot water storage tank 2 taken out from the forward pipe 9 is boiled by the heat pump unit 3, returned to the hot water storage tank 2 from the return pipe 10, and stored in hot water. Hot water in the hot water storage tank 2 is pushed up, and hot water in the upper part of the hot water storage tank 2 is pushed out from the hot water discharge pipe 7 to supply 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 heating circulation pump 16 that circulates to the refrigerant-water heat exchanger 12 through the forward pipe 9 and the return pipe 10 and a heat pump control unit 17 that controls driving thereof are provided. Carbon dioxide is used as 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 water to be heated 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 becomes 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.

  Next, 18 is a bath heat exchanger composed of a stainless steel snake pipe for heating the hot water in the bathtub 6, which is arranged at the upper part in the hot water storage tank 2, and the bath heat exchanger 18 is connected to the bath heat exchanger 18. A bath circulation circuit 22 composed of a pipe 19 and a bath return pipe 21 provided with a bath circulation pump 20 is connected so that hot water in the bathtub 6 can be circulated, and hot water in the bathtub 6 is heated by high-temperature water in the hot water storage tank 2. Insulating or chasing is done.

  If the amount of heat in the hot water storage tank 2 is insufficient at the time of heat insulation or reheating, the heating pump unit 3 performs a boiling operation. At this time, the heated hot water is not the return pipe 10 but the bath heat exchanger. 18 is returned via an intermediate return pipe 23 communicated with the upper part of the hot water storage tank 2 facing the pipe 18, and a three-way valve 24 constituting a flow path switching means is provided at a branch portion between the return pipe 10 and the intermediate return pipe 23. The three-way valve 24 is provided so that the return pipe 10 is selected in the heating operation during the midnight time zone, and the intermediate return pipe 23 is selected in the heating operation other than this time zone.

  Reference numeral 25 denotes a bath return temperature sensor that detects the remaining hot water temperature that flows into the bath heat exchanger 18 through the bath return pipe 21, and reference numeral 26 denotes an outflow from the bath heat exchanger 18 to the bathtub 6 through the bath outlet pipe 19. It is a bath temperature sensor that detects the temperature of bathtub water.

  Next, 27 is 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 28 branched from the water supply pipe 9. The mixing ratio is controlled so that the hot water temperature detected by the provided hot water temperature sensor 30 becomes the hot water supply set temperature set by the user using the remote controller 5.

  31 is a hot water pipe that branches off from the hot water supply pipe 29 and communicates with the bath return pipe 21. The hot water pipe 31 includes a hot water valve 32 that starts / stops hot water filling the bathtub 6, and a bathtub 6. A bath flow rate counter 33 that counts the amount of hot water filled in and a check valve 34 that prevents the bath water from flowing back to the hot water supply pipe 29 is provided.

  Next, a plurality of hot water storage temperature sensors 35 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 35a, 35b, 35c, 35d, 35e from the top. The temperature information detected by the temperature sensor 35 detects how much heat remains in the hot water storage tank 2 and how far it has been replenished by boiling, and also detects the vertical temperature distribution in the hot water storage tank 2 It is.

  The remote controller 5 is provided with a hot water supply temperature setting switch 36 for setting the hot water supply set temperature and a bath temperature setting switch 37 for setting the bath set temperature, respectively. Automatic bathing that fills the amount of water filled with a water filling amount setting switch (not shown) and keeps it warm for a predetermined time and replenishes water at a predetermined temperature to the set water level when the water level in the bathtub 6 drops by a predetermined amount. A switch 38 and a reheating switch 39 that repels bathtub water are provided.

  A hot water supply control unit 40 includes a microcomputer that receives the input of each sensor in the hot water storage tank unit 1 and controls the driving of each actuator, and constitutes a control unit. The remote controller 5 is connected to the hot water supply control unit 40 wirelessly or by wire so that the user can set an arbitrary hot water set temperature and bath set temperature, and the bath set temperature + alpha is heated up to the target temperature. This + alpha is variable depending on the remaining hot water temperature of the bathtub 6, and when the remaining hot water temperature is 15 ° C and the bath set temperature is 40 ° C, 25 ° C is set as + alpha, and the remaining hot water temperature is 40 ° C. When the bath set temperature is 42 ° C., the hot water supply control unit 40 is preset for each temperature difference so that the minimum value of 10 ° C. becomes + alpha.

  On the condition that the bath automatic switch 38 or the reheating switch 39 of the remote controller 5 is pressed in the hot water supply control unit 40, the amount of heat in the hot water storage tank 2 has decreased to a temperature or amount at which heat retention or reheating cannot be performed. It is provided with a heat quantity securing means 41 that detects this and automatically makes the above-described heating operation to drive the heat pump unit 3.

  42 is an automatic water replenishing means for automatically replenishing water when the bath automatic switch 38 is turned on, and automatically monitors the water level of the bathtub 6 with a water level sensor 43 comprising a pressure sensor provided in the bath outlet pipe 19. Is detected, and hot water at the bath set temperature is replenished through the hot water pipe 31 to the set water level.

  44 is an automatic heat retaining means for reheating for automatic bath operation when the automatic bath switch 38 is turned on, and has a timer means 45 to drive the bath circulation pump 20 every 20 minutes during the heat retention for 4 hours. The bath return temperature sensor 25 detects the current temperature of the hot water in the bathtub 6 and performs reheating using the bath heat exchanger 18 when the temperature is equal to or lower than a predetermined temperature. To keep warm.

  In addition, 46 is an overpressure relief valve for releasing the overpressure of the hot water storage tank 2, 47 is a pressure reducing valve for reducing the pressure of the water supply, 48 is a hot water supply flow rate counter for counting the amount of hot water to be supplied, and 49 is detecting the temperature of the water supply. It is a feed water temperature sensor.

Next, the operation of the first embodiment will be described.
First, when the hot water storage temperature sensor 35 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 40 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 compressor 11 and then starts to drive the heating circulation pump 16, and cools the low temperature water of about 5 to 20 ° C. taken out from the forward pipe 9 connected to the lower part of the hot water storage tank 2. The water heat exchanger 12 is heated to a high temperature of about 70 to 90 ° C., returned to the hot water storage tank 2 from the 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 to store the high temperature water. Go. When the hot water storage temperature sensor 35 detects that the necessary amount of heat has been stored, the hot water supply control unit 40 issues a boiling stop command to the heat pump control unit 17, and the heat pump control unit 17 stops the compressor 11 and performs heating circulation. The pump 16 is also stopped to end the boiling operation.

  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 27 through the hot water discharge pipe 7 and is mixed with the low temperature water from the hot water supply bypass pipe 28, and the hot water supply control unit 40 sets the mixing ratio of the hot water supply mixing valve 30. The adjusted hot water of 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.

  On the other hand, bathing is performed by pressing the bath automatic switch 38 or the chasing switch 39 of the remote controller 5, and the bath water whose temperature has been lowered by driving the bath circulation pump 20 is circulated through the bath heat exchanger 18. Then, heat is exchanged with the hot water in the hot water storage tank 2 so that the temperature is raised and returned to the bathtub 6 in order, and when the return hot water temperature by the bath temperature sensor 26 reaches the bath set temperature, the reheating of the bath is finished. This is the same as the chasing during the heat insulation.

  Next, the determination of the reheating operation will be described with reference to the flow chart of FIG. 2. The hot water storage temperature sensor 35 detects the amount of heat in the upper part of the hot water storage tank 2 where the bath heat exchanger 18 is located. 2, when the heat quantity securing means 41 determines that the heat quantity is insufficient for reheating, the process proceeds to step 51 with YES, and the bath automatic switch 38 and the reheating switch 39 of the remote controller 5 are further pressed by the heat quantity securing means 41. It is determined whether or not it is in a state of being lifted, and only when it is pressed and YES, in step 52, the reheating operation is performed.

  The reheating operation is performed by driving the heating circulation pump and heat pump controller 17 and the three-way valve 24. The reheating operation by the heat pump unit 3 is started, and the three-way valve 24 is reheating operation. The pipe 10 side is closed, the intermediate return pipe 23 side is opened, and hot water heated to a high temperature by the heat pump unit 3 is intensively supplied to a portion of the hot water storage tank 2 where the bath heat exchanger 18 is located. In order to shorten the boiling time, the completion of the boiling operation is performed at step 53 by setting the bath set temperature + alpha to the temperature of the bath heat exchanger 18 portion of the hot water storage tank 2 as shown in the flowchart of FIG. If YES, the process proceeds to step 54 with YES and ends.

  + Alpha, as described above, the smaller the difference between the bath set temperature and the remaining hot water temperature of the bathtub 6, the smaller the temperature. The lower the target temperature, the shorter the boiling time, and the longer the reheating operation. As a result, it is possible to reduce the waiting time of the user, improve the usability, and prevent unnecessary boiling, and it is economical and improves the efficiency.

  Furthermore, only when the remote control 5 instructs the warming and reheating of the bath, and the user's request is clear, when the amount of heat in the hot water storage tank 2 decreases and the heat cannot be kept or reheated, it will boil automatically. It is designed to increase the amount of heat that can be kept warm and recharged when instructed, and to respond to the user's request without fail. Since it is performed only when the user's request can be confirmed, the user's consent is obtained and it is economically good.

  The heated hot water heated by the heat pump unit 3 at the time of boiling is directly returned to the upper part of the hot water storage tank 2 where the bath heat exchanger 18 is located via the intermediate return pipe 23, so that the portion requiring boiling is directly boiled. It is possible to increase the temperature, and since it does not needlessly increase the temperature, it can shift to reheating in a short time, and can perform efficient heating with an economical temperature increase, which is extremely convenient to use.

Next, a second embodiment of the present invention shown in FIG. 4 will be described. The same parts as those of the first embodiment are denoted by the same reference numerals, the description thereof will be omitted, and only different parts will be described.
In the external heat exchange system in which the bath heat exchanger 18 goes out of the hot water tank 2, the upper portion of the hot water tank 2 and the bath heat exchanger 18 communicate with each other through a hot water supply pipe 53, Heat is exchanged, and the low temperature hot water is returned to the lower part of the hot water storage tank 2 through a hot water return pipe 55 provided with a heat exchange pump 54.

  In this configuration, an effect similar to that of the first embodiment can be obtained only by having the bath heat exchanger 18 outside, and an intermediate return pipe facing the connection port portion of the hot water supply pipe 53 at the time of heating. Since the heated hot water is returned from 23, hot water sent to the bath heat exchanger 18 for heat exchange can be preferentially formed.

The schematic block diagram of the hot water storage type hot water supply apparatus which shows 1st Embodiment of this invention. The block diagram of the principal part electric circuit. The flowchart explaining the determination of the same boiling increase driving | operation. The schematic block diagram of the hot water storage type hot water supply apparatus which shows 2nd Embodiment of this invention.

Explanation of symbols

2 Hot water storage tank 3 Heat pump unit (heating means)
5 Remote control 6 Bath 18 Bath heat exchanger 20 Bath circulation pump 22 Bath circulation circuit

Claims (1)

  The hot water storage tank for storing hot water heated by the heating means, the bath circulation circuit connected to the bathtub, the bath circulation pump for circulating hot water in the bathtub to the bath circulation circuit, and the hot water in the bathtub circulating in the bath circulation circuit are described above. A bath heat exchanger for exchanging heat with the hot water in the hot water storage tank, wherein the bath heat exchanger performs heat exchange with the hot water in the hot water storage tank to heat and retreat the bath. A hot water storage type hot water supply apparatus characterized in that, at the time of reheating operation with a reduced amount of heat, the reheating target temperature is varied according to the remaining hot water temperature of the bathtub.

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