JP4377843B2 - Hot water storage water heater - Google Patents

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. When 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 particularly configured as follows. In claim 1, a hot water storage tank for storing hot water heated by the heating means, a bath circulation circuit connected to the bathtub, and hot water in the bathtub are provided. A bath circulation pump that circulates in the bath circulation circuit, and a bath heat exchanger that exchanges the hot water in the bathtub circulating in the bath circulation circuit with the hot water in the hot water storage tank, provided in the upper part of the hot water storage tank, The amount of heat in the hot water storage tank is reduced, and the heated hot water during the heating operation by the heating means is returned to the upper part of the hot water storage tank through an intermediate return pipe facing the bath heat exchanger, and the heated hot water from the heating means is The flow rate by driving the heating circulation pump returned to the hot water storage tank is increased as the boiling point increases and the target temperature is lower.

Further, in claim 2, a hot water storage tank for storing hot water heated by the heating means, a bath circulation circuit connected to the bathtub, a bath circulation pump for circulating hot water in the bathtub to the bath circulation circuit, and a circulation through the bath circulation circuit A bath heat exchanger for exchanging heat from the hot water in the hot water tank with the hot water in the hot water storage tank is provided outside the hot water storage tank. The heated hot water is returned to the upper part of the hot water storage tank through an intermediate return pipe facing the hot water supply pipe to the bath heat exchanger, and the flow rate by driving the heating circulation pump for returning the heated hot water from this heating means to the hot water storage tank is increased. The higher the boiling point and the lower the target temperature, the faster.

According to the first and second aspects of the present invention, the hot water heated by the heating means at the time of boiling is not returned to the upper end of the hot water storage tank, the position of the bath heat exchanger and the hot water supply pipe of the bath heat exchanger Because it is returned directly to the upper part where is located, boiling can be completed in a short time and the waiting time until reheating can be shortened, and efficient heating can be performed with economical boiling, making it extremely easy to use. It ’s good.
In addition, when the bath set temperature is low or the remaining hot water temperature of the bath is high, the target boiling temperature is also low. Therefore, the flow rate by driving the heating circulation pump can be increased to further shorten the boiling time. is there.

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, it is possible to boil low temperature water 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. Insulation or chasing is performed.

  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.

  A bath return temperature sensor 25 detects the temperature of the bath water flowing into the bath heat exchanger 18 through the bath return pipe 21, and 26 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.

  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 has a hot water filling valve 32 for starting / stopping 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 hot water set by a hot water amount setting switch (not shown) and keeps it warm for a predetermined time, and when the water level in the bathtub 6 falls by a predetermined amount, replenishes the water to the set temperature. 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 controller 40 wirelessly or by wire so that the user can set an arbitrary hot water set temperature and bath set temperature. This bath set temperature + alpha (about + 10 ° C. or so) Increases to the target temperature.

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

  43 is an automatic warming means for reheating for automatic bathing when the bath automatic switch 38 is turned on, and has a timer means 44 to drive the bath circulation pump 20 every 20 minutes during the 4-hour warming. 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, 45 is an overpressure relief valve for releasing the overpressure of the hot water storage tank 2, 46 is a pressure reducing valve for reducing the pressure of the water supply, 47 is a hot water supply flow rate counter for counting the amount of hot water to be supplied, and 48 is for 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 control section 40 determines the mixing ratio of the hot water supply mixing valve 30. 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.

  On the other hand, when reheating the bath, if the reheating switch 39 of the remote controller 5 is pressed in step 49, the process proceeds to step 50 with YES and the heat amount of the bath heat exchanger 18 in the hot water storage tank 2 and the heat amount necessary for reheating. The remaining heat quantity is calculated by the hot water storage temperature sensor 35, and the temperature and quantity are calculated by the hot water supply control section 40, and the necessary heat quantity is calculated by the hot water supply control section 40 based on the bath set temperature and the current bath water temperature. If it is determined that the amount of remaining heat can be reclaimed, the process proceeds to step 51 with YES, and the bath circulating pump 20 is driven to turn the bath water whose temperature has decreased into the hot water in the hot water storage tank 2 by the bath heat exchanger 18. A reheating operation is performed in which the temperature is raised by exchanging heat with the water and returning to the bathtub 6.

  If the remaining heat cannot be replenished in step 50, the process proceeds to step 52 with NO to start the reheating operation by the heat pump unit 3, and since the three-way valve 24 is reheating operation, the return pipe 10 side is closed. At the same time, the intermediate return pipe 23 side is opened, and then the process proceeds to step 53 to determine whether the target temperature is 60 ° C. or higher. If YES, the heating circulation pump 16 is driven at a normal flow rate in step 54. In step 55, the heating circulation pump 16 is driven at a flow rate faster than usual. In step 56, the heating operation is completed by storing hot water of a target temperature and a target amount of heated hot water.

  Accordingly, 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 that needs to be heated up is directly adjusted. Therefore, it is possible to carry out efficient heating with an economical boiling, and it is very convenient to use.

  Further, when the bath set temperature is low or the remaining hot water temperature of the bath is high, the boiling target temperature is also lowered. Therefore, the flow rate of the heating circulation pump 16 can be increased to further increase the boiling time. .

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.
The bath heat exchanger 18 is connected to the outside of the hot water tank 2, and the upper part of the hot water tank 2 and the bath heat exchanger 18 are communicated with each other via a hot water supply pipe 58. Heat is exchanged, and the hot and cold water is returned to the lower part of the hot water storage tank 2 via the hot water return pipe 60 provided with the heat exchange pump 59.

  In this configuration, as in the first embodiment, the heated hot water is returned from the intermediate return pipe 23 opposed to the connection port portion of the hot water supply pipe 58 at the time of boiling, so that the bath heat exchanger 18 Hot water sent for heat exchange is preferentially formed, and the same effect as that provided with the bath heat exchanger 18 in the hot water storage tank 2 can be obtained.

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 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)
6 Bath 10 Return pipe 18 Bath heat exchanger 20 Bath circulation pump 22 Bath circulation circuit 23 Intermediate return pipe 24 Three-way valve (flow path switching means)

Claims (2)

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 the 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 is provided at the upper part in the hot water storage tank, and the amount of heat in the hot water storage tank is reduced, and the heated hot water at the time of heating operation by the heating means is: While returning to the upper part of the hot water storage tank through the intermediate return pipe facing the bath heat exchanger, the flow rate by the heating circulation pump that returns the heated hot water from this heating means to the hot water storage tank is increased as the target temperature is increased. Hot water storage hot water supply device characterized by things. 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 the 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 is provided outside the hot water storage tank. The amount of heat in the hot water storage tank is reduced, and the heated hot water during the heating operation by the heating means is a bath. While returning to the upper part of the hot water storage tank via the intermediate return pipe facing the hot water supply pipe to the heat exchanger, the flow rate by driving the heating circulation pump that returns the heated hot water from this heating means to the hot water storage tank is increased and the target temperature is increased. Hot water storage type hot water supply device characterized by being faster as it is lower.

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