JPS60233454A - Solar heat water heater - Google Patents

Abstract

PURPOSE:To raise the utility of solar energy as well as enhance the raisability of temperature by a method in which a heat pipe independent of the closed circuit of both modes is provided, the difference of temperature between the evaporating portion and condensing portion of the heat pipe is detected, and switching of both modes is exactly made. CONSTITUTION:The situation that insolation amount is increased, a heat pipe 11 is operated, and the temperature of the evaporating portion of the heat pipe 11 in the heat collector 1 becomes higher than the condensing portion is detected by temperature difference detectors 12a and 12b. A compressor 8 is then stopped by a controller 13, and the temperature of water in a hot water storage tank 4 is raised by the solar energy by a loop-type heat pipe mode operation in which the working liquid in the circuit is returned through a heat exchanger 5b from the evaporating portion 3 to the evaporating portion 3. On the contrary, when the insolation amount is less and the heat pipe 11 does not work, the compressor 8 is operated by detection of the detectors 12a and 12b, and the temperature of water in the tank 4 is raised by the atmospheric heat mainly by a heat pump mode operation in which the working liquid in the circuit is returned through the compressor 8 and the heat exchanger 5a from the evaporating portion 3 to the evaporating portion 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solar water heater having both a loop heat pipe action and a heat pump action.

Conventional configuration and its problems Conventional solar water heaters do not raise the temperature when there is insufficient solar radiation, on rainy days, or at night. Therefore, water heaters that switch to heat pump operation have been devised in such cases, but this type of solar water heater is installed inside a heat collecting plate 1, as shown in Figures 1 and 2. The working fluid naturally flows down into the refrigerant pipes 2 in the heat collecting plate 1 inside the hot water storage tank 3, in which the refrigerant pipes 2, in which the working fluid as a latent heat medium is sealed, are installed above the heat collecting plate 1. An expansion valve 4 and a solenoid valve 5 are installed in parallel in the middle of the refrigerant pipe 2, which is connected in a closed loop and returns from the hot water storage tank 3 to the heat collection plate 1. A compressor 6 is provided in the middle of the refrigerant pipe 2 from the heat plate 1 to the hot water storage tank 3, and the heat collecting plate 1 and the compressor 6
A three-way valve 7, an expansion valve 8, and a fin tube 9 are installed on the way
, and an accumulator 10 are connected in series, and the other connection port of the three-way valve 7 bypasses the compressor 6 and is connected to the refrigerant pipe 2 in the hot water storage tank 3. Further, the solenoid valve 11 was provided to bypass the three-way valve 7 and the expansion valve 8 and short-circuit the fin tube 9 and the refrigerant pipe 2 of the heat collecting plate 1.

In the above WR configuration: If the amount of solar radiation exceeds a certain set value, the three-way valve 7 is switched to connect the pipes A and B, the solenoid valve 11 is closed, and the solenoid Open the valve 5 to operate in the loop heat pipe mode shown by the arrow in Figure 1. If the amount of solar radiation does not reach a certain set value, open the three-way valve 7 to operate the pipe as shown in Figure 2. Switch B and C to communicate, close solenoid valve 5, and close compressor 6.
First, the working fluid accumulated in the refrigerant pipe 2 in the heat collecting plate 1 is introduced into the expansion valve 8 and gasified, and when the working fluid in the refrigerant pipe 2 in the heat collecting plate 1 runs out, the electromagnetic The valve 11 was opened and the heat pump mode was operated as indicated by the arrow in FIG.

In such a conventional configuration, switching between loop heat pipe mode operation and Bee 1 pump mode operation is performed depending on whether the amount of solar radiation is higher or lower depending on a certain set value.
Even if the amount of solar radiation is higher than the set value, the water temperature in the hot water storage tank 3 may be too high to operate in the loop heat pipe mode.Also, even if the amount of solar radiation is lower than the set value, if the outside temperature is high and the water temperature is low, the loop type heat pipe In some cases, it is possible to drive in mode. Furthermore, when the amount of solar radiation fluctuates, switching between both modes becomes more frequent, and the operating time of the loop heat pipe mode, which contributes solar heat, actually becomes shorter. Therefore, switching control using the amount of solar radiation as a detection means has a problem in that it is not a reliable means for obtaining sufficient temperature raising performance.

OBJECT OF THE INVENTION The present invention solves such conventional problems, and provides a simple device for switching between the L-rap type heat pipe mode and the heat pump mode in a solar water heater that also serves as a collector serving as an evaporation section. The purpose is to increase the contribution rate of solar heat and improve temperature rise performance.

Structure of the Invention To achieve this object, the present invention provides a heat collector having an evaporator section equipped with heat collecting fins for evaporating a working liquid of a latent heat medium, and a heat collector located above the heat collector to collect heat for condensation. A closed circuit is constructed with a hot water storage tank containing two exchangers, an outgoing pipe from the heat collector to each heat exchanger, and a source pipe, and a compressor is installed on the way to one of the outgoing pipes to the heat exchanger. The base tube of the heat exchanger is equipped with an expansion valve, and a loop heat pipe mode circuit and a heat pump mode circuit are purchased, and the basic configuration is that the heat collector serves as the evaporation part of both circuits. . In addition, a heat pipe is provided that is independent of the closed circuit in both modes, and has an evaporation section with heat collection fins in the heat collector and a condensation section in the hot water storage tank. This system is equipped with a temperature difference detector and a controller that determines mode switching based on the temperature difference detection.

With this configuration, under conditions where the temperature of the evaporating section in the heat collector is higher than that of the condensing section in the hot water storage tank and operation is possible in the loop heat pipe mode, the heat pipe is also activated, and the evaporating section of the heat pipe condenses. By detecting this temperature difference, the compressor is stopped and operated in loop heat pipe mode, and conversely, when the temperature in the evaporating part of the heat pipe is lower than the condensing part, the compressor is operated in loop heat pipe mode. , the compressor can be activated and operated in heat pump mode.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 3, 1 is a heat collector having an evaporation section 3 equipped with heat collecting fins 2, 4 is located above the heat collector 1, and a condensing heat exchanger 5a for heat pump mode; This is a hot water storage tank that houses a condensing heat exchanger 5b for loop-type heat pipe mode. Heat exchanger 5a and heat exchanger 5b
A closed circuit is constituted by the heat collector 1, the outgoing pipe 6, and the original pipe 7. The outgoing pipe 6 branches in the middle, and one side is connected to the heat exchanger 5a via the compressor 8, and the other side is connected to the heat exchanger 5a via the compressor 8. It is connected to the heat exchanger 5b. Furthermore, the heat exchanger 5a is connected to the base pipe 7 via an expansion valve 9, and the heat exchanger 5b is connected to the raw pipe 7 via a check valve 10.

In addition, a heat pipe 11 is provided in the heat collector 1, which is independent of the closed circuit, and has an evaporating part equipped with heat collecting fins 2 and a condensing part in the hot water storage tank 4. Temperature difference detectors 12a and 12b between the evaporating section and the condensing section of the pipe and a controller 13 that determines whether to start or stop the compressor 8 based on the temperature difference detection are provided.

In the above configuration, the amount of solar radiation increases and the heat pipe 11
is activated, and the temperature difference detectors 12a and 12b detect that the temperature of the evaporating part of the heat pipe 11 in the heat collector 1 has become higher than that of the condensing part of the heat pipe 11 in the hot water storage tank 4, and the controller 13 By stopping the compressor 8, the heat collector 1
The temperature of the heat collecting fins 2 in the circuit rises, and the working fluid in the circuit passes from the evaporator 3 to the outgoing pipe 6, passes through the condensing heat exchanger 5b, passes through the raw pipe 7, and returns to the heat collector 1. The temperature of the water in the hot water storage tank 4 is raised by solar heat due to the loop heat pipe mode operation in which the water returns to the evaporator section 3 in the hot water tank 4 repeatedly. vice versa,
When the amount of solar radiation is such that the girl heat pipe 11 does not operate,
The controller 13 operates the compressor 8 upon detection by the temperature difference detectors 12 & 12b, and the working fluid in the circuit passes from the evaporator 3 through the outgoing pipe 6, is adiabatically compressed by the compressor 8, and generates heat for condensation. Due to the heat pump mode operation, which repeats the cycle of passing through the exchanger 5a, passing through the expansion valve 9, the original tube 7, and returning to the evaporation section 3 in the heat collector 1, the water temperature in the hot water storage tank 4 is mainly atmospheric heat. The temperature rises due to Note that the check valve 10 is provided to prevent a short circuit of the backflow circuit to the heat exchanger 5b during operation in the heat pump mode.

In this way, with the above configuration, it is possible to accurately determine which mode is more advantageous to operate between the loop heat pipe mode, which mainly uses solar heat, and the heat pump mode, which mainly uses atmospheric heat. In driving mode,
This has the effect of increasing the temperature of the water in the hot water storage tank.

Effects of the Invention As described above, according to the solar water heater of the present invention, one heat collector serves as the evaporation section for the ρ-type heat pipe mode and the heat pump mode, and the condition detection for mode switching is performed for both modes. A heat pipe is provided that is independent of the circuit, and the operation is performed using the difference in temperature between the evaporating and condensing parts of the heat pipe, so the operating conditions for the loop heat pipe mode, which is a more energy-saving mode of operation than the heat pump mode that requires power, are as follows: It can be selected accurately regardless of the water temperature of the hot water storage tank or the amount of solar radiation, and even if the amount of solar radiation fluctuates, the temperature of the heat pie can be efficiently raised using solar heat and atmospheric heat.

[Brief explanation of drawings]

1 and 2 are block diagrams of a conventional solar water heater, and FIG. 3 is a block diagram of a solar water heater showing an embodiment of the present invention. 1... Heat collector, 2... Heat collecting fin, 3
...Evaporation section, 4...Hot water storage tank, 5a, 5
b... Heat exchanger, 6... Outgoing pipe, 7...
... Master tube, 8 ... Compressor, 9 ...
Expansion valve, 11...Heat pipe, 12a, 12
b... Temperature difference detector, 13... Controller. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] a heat collector having an evaporation section equipped with heat collecting fins for evaporating the working fluid of the latent heat medium; a hot water storage tank located above the heat collector and containing two heat exchangers for condensation; A closed circuit is constituted by an outgoing pipe and a return pipe from the heating device to each of the heat exchangers,
A compressor is provided on the outgoing pipe to one of the heat exchangers, an expansion valve is provided in the return pipe of the weak exchanger, and a loop heat pipe mode circuit and a heat pump mode circuit are connected through the compressor and the expansion valve. , the evaporation section of both mode circuits is shared by the heat collector, and the mode switching is determined by an evaporator equipped with heat collecting fins in the heat collector independently of the closed circuit. and a heat pipe having a condensing part in the hot water storage tank, and comprising a temperature difference detector between an evaporating part and a condensing part of the heat pipe, and a controller that determines mode switching based on the temperature difference detection. Solar water heater.