JPH0460384A - Controlling method for heat accumulation type hot water supplying apparatus and heat accumulation type hot water supplying apparatus for executing the same - Google Patents

Abstract

PURPOSE:To prevent excess generation of operating fluid vapor by closing a steam tube when a hot water supply is stopped to raise the pressure of an evaporator, forcibly returning back the fluid to a liquid return tube, and then closing the tube to stop flow the fluid to the evaporator side. CONSTITUTION:The upper parts of an evaporator 5 and a condenser 9 are connected via a steam tube 11 having a first opening/closing valve. The lower parts of the evaporator 5 and the condenser 9 are connected via a liquid return tube 13 having a second opening/closing valve. When hot water supply is stopped, if a hot water supply valve 10 is closed, the first valve is initially closed. As a result, when steam is filled in the evaporator 5 and operating fluid 16 is forcibly returned back to the tube 13 side, the second valve is closed to prevent flow of the fluid 16 to the evaporator 5. Simultaneously, the valve 12 is opened, and the steam is fed to the condenser 9 to be condensed. Accordingly, since the steam is not generated any more in the evaporator 5, excess generation of the steam can be prevented to prevent rise of inner pressure in a pipe.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a method for controlling a water heater using a heat storage material as a heat source, and a water heater for carrying out the method, and in particular to a method for controlling a water heater using a heat storage material as a heat source, and particularly to a method for controlling a water heater using a heat storage material as a heat source. The present invention relates to a control method for a type of water heater that feeds running water, and a water heater for implementing the method.

Conventional technology For water heaters that obtain hot water using electrical energy, it is preferable to use late-night electricity, where the energy unit price is low, so in the past, a large-capacity hot water storage tank was installed to store hot water at night and then use it when needed. I am trying to use . However, in facilities with a high demand for hot water, it is necessary to increase the volume of the hot water storage tank, so there is a problem that a large installation space must be secured.

Therefore, the present applicant and others have already proposed a water heater that can utilize late-night electricity and can be downsized. This heats water by extracting the heat stored in a heat storage material using a loop heat pipe, and the evaporating section and condensing section are connected by a steam pipe and a liquid return pipe, forming a circulation path as a whole. A working fluid is sealed inside the evaporator, and a heat storage material such as a sensible heat storage material or a latent heat storage material is provided in the evaporation section so that heat can be exchanged.
Further, the condensing section is configured as a heat exchanger to give heat to the flowing water to make it hot water, and the liquid return pipe is further provided with an on-off valve for controlling the flow of the working liquid. In this water heater, by flowing water around the outer circumference of the condensing section, a temperature difference is created between the evaporating section and the condensing section, so when the on-off valve is opened, the working fluid flows into the evaporating section and evaporates, resulting in the vapor Since the water radiates heat and condenses in the condensing section, hot water can be quickly obtained. Since the heat storage temperature can be increased to increase the heat storage capacity, it is possible to reduce the size.

Problems to be Solved by the Invention In the above-mentioned water heater, in order to obtain hot water at the required temperature almost at the same time as the hot water operation such as opening the faucet,
It is common practice to reduce the heat capacity in the condensing part as much as possible. Specifically, for example, in a loop heat pipe, a water jacket is attached to the outer periphery of the condensing part to form a water passage with a small volume. The water supplied to the water passage is heated to a required temperature while passing through the water passage. On the other hand, heat pipes operate when there is a temperature difference, so in the water heaters mentioned above, an on-off valve installed in the liquid return pipe is used to stop and stop the hot water output in order to prevent unnecessary heat radiation from the heat storage material. At the same time, it is closed to stop the supply of working fluid to the evaporator. However, even if the on-off valve is closed and the supply of hydraulic fluid is stopped due to the stoppage of hot water output, some hydraulic fluid remains inside the evaporator and in the pipes between the evaporator and the on-off valve. The so-called residual working fluid absorbs heat from the heat storage material and evaporates. In conventional water heaters, the heat capacity of the condensing section, which is the heat dissipation point, is small, so the steam generated by the evaporation of the remaining working fluid does not provide heat to the steam pipe between the evaporating section and the condensing section. Since it does not dissipate heat, it cannot be condensed, and as a result, the internal pressure of the heat vibrator becomes abnormally high, which may lead to leakage of working fluid from the heat vibrate, decrease in durability, and even damage to the heat vibre. Ta.

This invention has been made in view of the above circumstances, and provides a method for controlling a regenerative water heater and a method for quickly removing residual working fluid from the evaporator to prevent an abnormal increase in the internal pressure of the heat vibrator. The purpose is to provide a water heater for

Means for Solving the Problems In order to achieve the above object, the method of the present invention includes an evaporation section capable of exchanging heat with the heat storage material and a condensation section located higher than the evaporation section capable of exchanging heat with running water. are connected to form a closed circulation path by a steam pipe and a liquid return pipe, and a working fluid that evaporates and condenses is sealed inside the circulation path to form a loop heat pipe. When stopping hot water supply, the steam pipe is closed to stop the flow of working fluid vapor to increase the pressure in the evaporator, and after the liquid-phase working fluid is pushed back from the evaporator to the liquid return pipe, the liquid return pipe is closed. This method is characterized by closing and stopping the flow of liquid-phase working fluid toward the evaporation section.

In addition, in order to carry out the above method, the water heater of the present invention includes an evaporator section capable of exchanging heat with the heat storage material and a condensing section located higher than the evaporator section and capable of exchanging heat with flowing water, which are connected to the steam pipe. Stopping hot water supply in a regenerative water heater that is connected to a liquid return pipe to form a closed circulation path, and a working fluid that evaporates and condenses is sealed inside the circulation path to form a loop heat pipe. A first on-off valve that is closed in accordance with the above is installed in the steam pipe, and a detector is provided to detect the amount of liquid-phase working fluid in the evaporator section, and the It is characterized in that a second on-off valve that is closed is interposed in the liquid return pipe.

Function: In the water heater targeted by this invention, when water is allowed to flow into the condensing section with sufficient thermal energy stored in the heat storage material and working fluid is supplied to the evaporation section, the working fluid is heated by the heat possessed by the heat storage material. The water is evaporated, and after the vapor flows to the condensing section, it radiates heat and condenses, thereby heating the water and producing hot water. When the hot water supply is stopped in this manner, the flow of the working fluid vapor in the steam pipe is first stopped, and this is done by closing the first on-off valve. Since the working fluid continues to evaporate in the evaporator,
When the pressure in the evaporator gradually increases and the working fluid in the liquid phase is pushed from the evaporator toward the liquid return pipe and almost disappears, that is, when the detector outputs a signal, the flow from the liquid return pipe to the evaporator increases. The inflow of liquid-phase working fluid is stopped, and this is done by closing the second on-off valve.

Therefore, in this invention, the pressure rises to the extent that the liquid-phase working fluid remaining in the evaporator is pushed back toward the liquid return pipe, but after that, the evaporator is in a dry-out state, so that working fluid vapor is generated. This prevents pressure from rising in the evaporator.

Example Next, the present invention will be explained with reference to examples.

First, an example of a heat storage type water heater according to the present invention will be described. FIG. 1 is a schematic diagram of the heat storage type water heater according to the present invention. It is configured to be performed using a vibrator 3. That is, the heat storage material 1 is composed of a metal block, a ceramic block, or the like, and has a built-in heater 4 such as an electric heater, and the evaporation part 5 of the heat vibe 3 penetrates the heat storage material 1. The heat exchange section 2 also includes a water supply pipe 6 and a hot water supply pipe 7.
The condensing part 9 of the heat vibe 3 penetrates the inside of the chamber 8 connected to the
0 is inserted.

The upper part of the evaporating part 5 and the upper part of the condensing part 9 are the steam pipe 11.
The steam pipe 11 is connected to the steam pipe 11 by a first on-off valve 12 such as a solenoid valve that opens and closes the pipe. Further, the lower part of the evaporating part 5 and the lower part of the condensing part 9 are connected by a liquid return pipe 13, and this liquid return pipe 13 includes a liquid reservoir part 14 and a solenoid valve located below the liquid reservoir part 14. A second on-off valve 15 consisting of the following is interposed.

The evaporating section 5 and the condensing section 9 are connected to a steam pipe 11 and a liquid return pipe 13.
In the closed circulation path connected as above,
A working fluid 16 that evaporates and condenses in a target temperature range, such as fluorocarbon, water, or alcohol, is sealed in a vacuum deaerated state. Inside the evaporator 5 or at a predetermined location closer to the evaporator 5 than the second on-off valve 15 is a detector 17 that detects that there is no liquid-phase working fluid 16 in the evaporator 5 and outputs a signal. The second on-off valve 15 is closed based on the output signal from the detector 17.

Next, the operation of the water heater described above, that is, the control method according to the present invention will be explained. When the heat storage material 1 is sufficiently heated by the heater 4, the on-off valves 12 and 15 are opened, and the hot water supply valve 10 is opened. 16 is heated by the heat of the heat storage material 1 and evaporates, and after the vapor flows to the condensing section 9, it radiates heat and condenses. As a result, the water supplied to the chamber 8 is heated and turned into hot water, which is sent to a predetermined location such as the kitchen via the hot water supply pipe 7. On the other hand, the condensed working fluid 16 flows back to the evaporator 5 via the liquid reservoir 14 and the liquid return pipe 13.

When stopping hot water supply, close the hot water supply valve 10 and the first
The on-off valve 12 is closed. As a result, the vapor of the working fluid 16 stops flowing to the condensing section 9 and fills the evaporating section 5, so that the internal pressure of the evaporating section 5 increases and the liquid-phase working fluid 16 in the evaporating section 5 flows toward the liquid return pipe 13. be pushed back. When almost the entire amount of the liquid-phase working fluid 16 is pushed out from the evaporator 5, the detector 17 outputs a signal, and the output signal closes the second on-off valve 15, causing the liquid-phase working fluid 16 to flow into the evaporator 5. This will be prevented. At the same time, the first on-off valve 12 opens and the working fluid vapor in the evaporator 5 flows into the condenser 9 to radiate heat and condense it. Therefore, the evaporator 5 dries out and no more working fluid vapor is generated, so that its internal pressure does not increase.

The above-mentioned control at the time of stopping the hot water supply can be performed by a simple relay circuit or a controller using a microcomputer, and the control routine for this purpose is shown in FIG. 2 for reference.

That is, when the hot water supply valve 10 is closed (YES in step 1), the first on-off valve 12 is closed (step 2), and then it is determined whether the detector 17 is ON or not (step 3).
), if "no", the process returns to step 2; if "yes", the process proceeds to step 4, where the second on-off valve 15 is closed and the first on-off valve 12 is opened (step 5).

As described in detail, according to the water heater control method of the present invention and the water heater for carrying out the method, after the hot water supply is stopped, a portion of the working fluid remaining in the evaporator part is removed. By evaporating, the entire amount of working fluid is pushed back to the liquid return pipe side,
After that, the liquid-phase working fluid will not flow into the evaporator and the evaporator will be in a dry-out state, so after stopping hot water supply,
That is, it is possible to prevent the working fluid vapor from being excessively generated after the working fluid vapor cannot be condensed in the condensing section, and to prevent the internal pressure of the heat pipe from becoming high pressure.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a water heater according to the present invention, and FIG. 2 is a flowchart showing a control routine of an example of the method of the present invention. DESCRIPTION OF SYMBOLS 1... Heat storage material, 2... Heat exchange part, 3... Loop heat pipe, 5... Evaporation part, 9... Condensation part, 10... Hot water supply valve, 11... Steam pipe , 12
...First on-off valve, 13...Liquid return pipe, 15...
- Second on-off valve, 16... Working fluid, 17... Detector.

Claims (2)

[Claims] (1) An evaporation section that can exchange heat with the heat storage material and a condensation section that is located higher than the evaporation section and can exchange heat with flowing water are connected to form a closed circulation path by a steam pipe and a liquid return pipe. In addition, when stopping hot water supply in a regenerative water heater in which a working fluid that evaporates and condenses is sealed inside the circulation path to form a loop heat pipe, the steam pipe is closed to stop the flow of working fluid vapor. The liquid phase working fluid is pushed back from the evaporator to the liquid return pipe, and then the liquid return pipe is closed to stop the flow of the liquid phase working fluid to the evaporator. A method of controlling a heat storage type water heater. (2) An evaporation section that can exchange heat with the heat storage material and a condensation section that is located higher than the evaporation section and can exchange heat with flowing water are connected to form a closed circulation path by a steam pipe and a liquid return pipe. In a regenerative water heater in which a working fluid that evaporates and condenses is sealed inside the circulation path to form a loop heat pipe, a first on-off valve that is closed when hot water supply stops is connected to the steam pipe. A detector for detecting the amount of liquid-phase working fluid in the evaporator is provided, and a second on-off valve that is closed based on the output signal of the detector is provided in the liquid return pipe. A heat storage type water heater characterized by: