JP2011226682A - Storage type water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage type water heater, capable of wastelessly carrying out efficient boiling up operation, in which hot water discharged as expanded water becomes unheated water in the lower part of a hot water tank, even when high temperature water of about half of the hot water tank is present in the upper part of the hot water tank.SOLUTION: The storage type water heater includes a hot water discharge pipe 6 whose one end is connected to the outlet of heat pump unit 200, a tank upper part pipe 7 whose one end is connected to the upper part of the hot water tank 1, a bypass pipe 8 whose one end is connected to the part lower than the center of the hot water tank 1, and a pressure releasing pipe 10 whose one end is connected to a pressure releasing valve 9. The storage type water heater includes: an electric four-way valve 5, capable of selecting the first flowing passage configuration in which the hot water discharge pipe 6 and the upper pipe 7 are in communication, and the bypass pipe 8 and the pressure releasing pipe 10 are in communication, and the second flowing passage configuration in which the hot water discharge pipe 6 and the bypass pipe 8 are in communication, and the tank upper part pipe 7 and the pressure releasing pipe 10 are in communication; and a controller 14 for controlling the electric four-way valve 5.

Description

  The present invention relates to a hot water storage type hot water heater that stores hot water heated by a heating means.

  As a conventional hot water storage type hot water heater, one that controls a flow path so that an intermediate pressure water discharge pipe connected to an intermediate portion of a hot water storage tank and an overpressure relief valve communicate with each other at the beginning of the boiling operation is known. (For example, refer to Patent Document 1). As a result, the water discharged as the expansion water is changed to medium-temperature water that has not yet been heated, so that efficient pressure adjustment can be performed without waste.

JP 2006-64344 A

  However, in the conventional hot water storage type hot water heater, when the temperature of the hot water storage tank intermediate part to which the intermediate hot water take-out pipe is connected is high, that is, when about half of the hot water hot water exists on the upper side of the hot water storage tank. The temperature of the hot water discharged as the expanded water increases, and it cannot be said that efficient pressure adjustment is always performed.

  The present invention has been made to solve the above-described problems. Even when high-temperature water about half of the hot water storage tank exists on the upper side of the hot water storage tank, the hot water discharged as the expanded water is not discharged. It is an object of the present invention to provide a hot water storage type hot water heater capable of performing efficient heating (boiling) operation without wasting water that has not yet been heated at the bottom of the hot water storage tank.

  A hot water storage type water heater according to the present invention comprises a hot water storage tank for storing hot water, a heating means for heating the hot water stored in the hot water storage tank, a hot water flow path having one end connected to the outlet of the heating means, and one end of the hot water storage tank. A tank upper channel connected to the upper part, a tank lower channel connected at one end to a part below the center of the hot water storage tank, a pressure relief channel connected at one end to the pressure relief valve, and a hot water flow channel And the tank upper flow path, the tank lower flow path and the pressure relief flow path communicate with each other, the hot water flow path and the tank lower flow path communicate with each other, and the tank upper flow path and A flow path switching means capable of selecting a second flow path form communicating with the pressure relief flow path, and a control unit for controlling the flow path switching means are provided.

  According to the present invention, even when high-temperature water about half of the hot water storage tank exists on the upper side of the hot water storage tank, the hot water discharged as the expansion water becomes unheated water at the lower part of the hot water storage tank, and is wasted. It is possible to perform an efficient heating (boiling) operation.

It is a block diagram of the hot water storage type water heater in Embodiment 1 of this invention. It is a figure (A), (B), and (C) showing the detailed structure of electric four-way valve 5. It is a flowchart which shows a boiling operation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a hot water storage type hot water supply apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, a hot water storage type water heater of this embodiment includes a hot water storage tank unit 100 and a heat pump unit 200 that functions as a heating means for heating (boiling) low temperature water led from the hot water storage tank unit 100. And.

  The hot water storage tank unit 100 includes a hot water storage tank 1 that stores hot water and can supply hot water to a desired hot water supply destination (shower, faucet, bathtub, etc.). One end of a water supply pipe 2 whose other end is connected to a water source is connected to the lower part (bottom part) of the hot water storage tank 1. In addition, one end of a water intake pipe 3 whose other end is connected to the inlet of the heat pump unit 200 (internal water refrigerant heat exchanger) is connected to the lower part (bottom part) of the hot water storage tank 1. In the middle of the incoming water pipe 3, a circulation pump 4 for conveying hot water in the lower part of the hot water storage tank 1 to the heat pump unit 200 is installed.

  One end of a hot water supply pipe (hot water flow path) 6 whose other end is connected to the first port 5a of the electric four-way valve 5 is connected to the outlet of the heat pump unit 200 (internal water refrigerant heat exchanger). The electric four-way valve 5 has four ports, that is, first to fourth ports 5a to 5d. One end of a tank upper pipe (tank upper channel) 7 whose other end is connected to the upper portion of the hot water storage tank 1 is connected to the second port 5b. One end of a bypass pipe (tank lower passage) 8 whose other end is connected to the lower part of the hot water storage tank 1 is connected to the third port 5c. The part to which the other end of the bypass pipe 8 is connected is a part below the center in the longitudinal direction of the hot water storage tank 1 and a part above the connection position of the water inlet pipe 3 described above.

  Further, one end of a pressure relief pipe (pressure relief flow path) 10 whose other end is connected to the pressure relief valve 9 is connected to the fourth port 5d. The other end of the pressure relief pipe 10 is open to the atmosphere. One end of a hot water supply pipe 11 is connected to the tank upper pipe 7. Hot water supplied to the hot water supply pipe 11 from the upper part of the hot water storage tank 1 is mixed with water supplied from the water supply pipe 2 side at the mixing valve 12 or 13 at an arbitrary ratio, and then supplied to the shower, faucet or bathtub. It has become so.

  A control unit 14 is built in the hot water storage tank unit 100. Further, a temperature detecting means 15 for detecting the temperature of the upper portion of the hot water storage tank 1 is attached to the upper portion of the hot water storage tank 1, and in the vicinity of the other end where the bypass pipe 8 and the hot water storage tank 1 are connected, A temperature detecting means 16 for detecting the temperature of the lower part of the hot water storage tank 1 is attached at that portion. The control unit 14 is configured to be able to switch the electric four-way valve 5 based on the temperatures detected by these temperature detection means 15 and 16.

  FIG. 2 is a diagram showing a detailed structure of the electric four-way valve 5. More specifically, FIG. 2 (A) is a view showing a first flow path configuration, FIG. 2 (B) is a view showing a second flow path configuration, and FIG. 2 (C) is a view of a ball valve 5f. It is a figure which shows the time of fixation on the way. As shown in FIG. 2, the electric four-way valve 5 includes an electric four-way valve body 5e in which the first to fourth ports 5a to 5d are formed. Inside the electric four-way valve body 5e, a ball valve 5f for switching the flow path is rotatably arranged. The ball valve 5f is rotationally driven by an electric motor 17 controlled by the control unit 14.

  The electric four-way valve 5 of this embodiment is configured to be able to select a first flow path configuration shown in FIG. 2 (A) and a second flow path configuration shown in FIG. 2 (B). As shown in FIG. 2 (A), the first flow path configuration is such that the tapping pipe 6 and the tank upper pipe 7 communicate with each other via the first port 5a and the second port 5b, and the third port 5c and the second port 5b are connected to each other. This is a flow path configuration in which the bypass pipe 8 and the pressure relief pipe 10 communicate with each other through the 4 port 5d. Further, as shown in FIG. 2B, the second flow path configuration is such that the hot water discharge pipe 6 and the bypass pipe 8 communicate with each other via the first port 5a and the third port 5c, and the second port 5b and This is a flow path configuration in which the tank upper pipe 7 and the pressure relief pipe 10 communicate with each other through the fourth port 5d.

  Further, the ball valve 5f of the electric four-way valve 5 can be used even when the ball valve 5f is stuck on the way and cannot rotate when switching between the first flow path configuration and the second flow path configuration. Each of the first to fourth ports 5a to 5d is configured to always maintain a state where it communicates with either one of the two left and right ports adjacent to each other. As described above, it is desirable that the valve utilized as the electric four-way valve 5 adopts a valve having a configuration in which the hot water storage tank 1 and the pressure relief valve 9 are always in communication in any switching state.

  By adopting the above configuration, even when the ball valve 5f is stuck in the middle and cannot be rotated, the pressure relief valve 9 connected to the electric four-way valve 5 and having the other end opened to the atmosphere is It becomes possible to communicate with the hot water storage tank 1. Thereby, it becomes possible to discharge the expanded water without fail, and it is possible to prevent an excessive pressure from being applied to the hot water storage tank 1.

  Next, the boiling operation of the hot water storage type water heater configured as described above will be described. FIG. 3 is a flowchart showing the boiling operation. As shown in FIG. 3, in step S <b> 1, it is determined whether or not there is an instruction to start boiling operation. The instruction to start the boiling operation is given by the control unit 14 when it is determined by the timepiece built in the control unit 14 that the time of midnight power has come, for example. As a result, when there is a boiling start instruction, the process proceeds to step S2, and the operation of the circulation pump 4 and the heat pump unit 200 is started, whereby the boiling operation is started. On the other hand, if there is no instruction to start boiling in step S1, the process waits.

  Next, in step S3, the electric four-way valve 5 is controlled so that the first flow path configuration (solid line a in FIG. 1) is obtained. When the first flow path form is selected, the hot water heated by the heat pump unit 200 to a high temperature passes through the hot water discharge pipe 6, the electric four-way valve 5 and the tank upper pipe 7 as shown in step S4. Hot water is stored from the top of 1. When the first flow path configuration is selected, the upper part of the hot water storage tank 1 is connected from the lower part of the hot water storage tank 1 through the bypass pipe 8, the electric four-way valve 5, and the pressure relief pipe 10 provided with the pressure relief valve 9. Expansion water having a temperature lower than that of hot water is discharged. In addition, when water containing air dissolved in water is heated by the heat pump unit 200 during the boiling operation, the solubility of air in water is lowered, and air is generated as a gas. The generated air accumulates in the upper part of the hot water storage tank 1.

  Next, in step S <b> 5, it is determined whether or not the temperature of the lower part of the hot water storage tank 1 detected by the temperature detection means 16 is equal to or higher than the temperature of the upper part of the hot water storage tank 1 detected by the temperature detection means 15. Alternatively, the determination may be made based on whether or not the detection value of the temperature detection means 16 is in the range from the temperature detected by the temperature detection means 15 to a value obtained by subtracting a predetermined value (temperature due to heat dissipation during boiling). Driving with the reduction in mind). As a result, when this determination is established, it is determined that hot water has been stored up to a place where the bypass pipe 8 and the lower part of the hot water storage tank 1 are connected, and the process proceeds to step S6. On the other hand, if this determination is not established, the process waits.

  Next, in step S6, the electric four-way valve 5 is controlled so that the second flow path configuration (broken line b in FIG. 1) is obtained. When the second flow path configuration is selected, the hot water heated by the heat pump unit 200 to a high temperature passes through the hot water discharge pipe 6, the electric four-way valve 5 and the bypass pipe 8 as shown in step S7. Hot water is stored from the bottom of the. When the second flow path configuration is selected, the hot water storage tank 1 is connected from the upper part of the hot water storage tank 1 through the tank upper pipe 7, the electric four-way valve 5, and the pressure relief pipe 10 provided with the pressure relief valve 9. The air accumulated in the upper part is discharged and the expanded water is discharged.

  Next, in step S8, it is determined whether or not there is an instruction to stop the boiling operation. As a result, when there is a boiling stop instruction, the process proceeds to step S9, and the boiling operation is stopped. For example, when the controller 14 determines that the incoming water temperature to the heat pump unit 200 has become a predetermined value or more by a temperature sensor provided in the incoming water pipe 3 (not shown), the controller 14 determines that the boiling operation is stopped. Made. On the other hand, if there is no boiling stop instruction in step S8, the process waits. Thereafter, as shown in step S10, when the user performs a hot water supply operation from a shower or a faucet, the air in the upper part of the hot water storage tank 1 is discharged as shown in step S7. Hot water supply with hot water not included is performed.

  As described above, the hot water storage type water heater of the present embodiment has a first flow path configuration in which the tap water pipe 6 and the tank upper pipe 7 communicate with each other, and the bypass pipe 8 and the pressure relief pipe 10 communicate with each other. There is provided an electric four-way valve 5 capable of selecting a second flow path configuration in which the hot water discharge pipe 6 and the bypass pipe 8 communicate with each other and the tank upper pipe 7 and the pressure relief pipe 10 communicate with each other. At the start of the boiling operation, first, the first flow path configuration is selected. Thereby, even when there is about half of the hot water in the hot water storage tank 1, the hot water discharged as the expanded water becomes unheated water present in the lower part of the hot water storage tank 1. For this reason, it becomes possible to perform efficient boiling operation (heating operation) without waste.

  In addition, when the temperature of the lower part of the hot water storage tank 1 becomes equal to or higher than the temperature of the upper part of the hot water storage tank 1 during the boiling operation performed by selecting the first flow path form, the second flow path form is selected. Thus, the electric four-way valve 5 is switched. Thereby, the air accumulated in the upper part of the hot water storage tank 1 can be discharged from the pressure relief valve 9 together with the expanded water. For this reason, it is possible to prevent hot water mixed with air from being discharged from a shower, a faucet or the like, and to improve convenience when supplying hot water.

  Moreover, since the connection site of the bypass pipe 8 is located above the hot water storage tank 1 relative to the connection site of the incoming water pipe 3, the temperature of the hot water discharged from the hot water storage tank 1 via the bypass piping 8 during boiling is The temperature of the hot water entering the heat pump unit 200 from the incoming water pipe 3 becomes higher. For this reason, the temperature of water entering the heat pump unit 200 can be lowered, and the boiling efficiency by the heat pump unit 200 can be improved.

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 3 Intake piping 4 Circulation pump 5 Electric four-way valve 5a-5d 1st-4th port 5e Electric four-way valve body 5f Ball valve 6 Hot water piping 7 Tank upper piping 8 Bypass piping 9 Pressure relief valve 10 Pressure relief piping 14 Control 15 and 16 Temperature detection means 17 Electric motor 100 Hot water storage tank unit 200 Heat pump unit

Claims (6)

A hot water storage tank for storing hot water,
Heating means for heating hot water stored in the hot water storage tank;
A hot water flow path having one end connected to the outlet of the heating means;
A tank upper channel, one end of which is connected to the upper part of the hot water storage tank;
A tank lower passage whose one end is connected to a portion below the center of the hot water storage tank;
A pressure relief flow path with one end connected to a pressure relief valve;
A first flow path configuration in which the hot water flow path and the tank upper flow path communicate with each other, and the lower tank flow path and the pressure relief flow path communicate with each other, and the hot water flow path and the tank lower flow path are provided. A flow path switching means capable of selecting a second flow path configuration that communicates with the tank upper flow path and the pressure relief flow path; and
A control unit for controlling the flow path switching means;
A hot water storage type water heater characterized by comprising:   The flow path switching means is connected to the first port connected to the other end of the hot water flow path, the second port connected to the other end of the tank upper flow path, and the other end of the tank lower flow path. The hot water storage type hot water heater according to claim 1, wherein the hot water storage type hot water heater is an electric four-way valve having a third port formed and a fourth port connected to the other end of the pressure relief passage. First temperature detecting means for detecting the temperature of the upper part of the hot water storage tank;
Second temperature detecting means for detecting the temperature of the lower part of the hot water storage tank;
Further comprising
The controller is configured to control the electric four-way valve based on the temperature of the upper part of the hot water storage tank detected by the first temperature detection means and the temperature of the lower part of the hot water storage tank detected by the second temperature detection means. The hot water storage type water heater according to claim 2, wherein the hot water storage type water heater is switched.   The control unit controls the electric four-way valve so that the first flow path configuration is selected at the start of a boiling operation for boiling hot water in the hot water storage tank using the heating means. The hot water storage type water heater according to claim 2 or 3.   The controller is configured such that, during execution of the boiling operation, the temperature of the lower part of the hot water storage tank detected by the second temperature detection means is the temperature of the upper part of the hot water storage tank detected by the first temperature detection means. The hot water storage type hot water supply device according to claim 4, wherein the electric four-way valve is switched so that the second flow path configuration is selected in the case described above. The electric four-way valve includes an electric four-way valve body in which the first to fourth ports are formed, a ball valve rotatably disposed inside the electric four-way valve body, and an electric motor that rotationally drives the ball valve; Including
When the ball valve rotates to switch between the first flow path configuration and the second flow path configuration, each of the first to fourth ports communicates with one of two adjacent ports. The hot water storage type hot water heater according to any one of claims 2 to 5, wherein the state is maintained.

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