JPS60233458A - Solar heat collector - Google Patents

Abstract

PURPOSE:To prevent the lowering of operational efficiency during the low-temperature period of the open air by extending the time of heat collecting operations by providing a controller by which to stop or restore the heat collecting operations when the temperature of the inlet of a heat collector reaches minus or plus set temperature. CONSTITUTION:In case where the temperature of the open air is lowered or frosting occurs on a heat collector 1, the temperature of the inlet of the heat collector is lowered. When a temperature sensor 12 reaches a minus set temperature T1, the heat collecting operation is stopped to prevent the liquid return operation of the compressor 3. After the stoppage of heat collecting operations, the temperature of the inlet of the heat collector becomes temperatures above the plus set temperature T2 in a short time by leak of refrigerant from high pressure side to lower pressure in a decompression device and then comes near the temperature of the open air. After the lapse of a fixed time period after the stoppage of heat collecting operations, the output of the temperature sensor 12 is detected by the controller 13, and when temperatures above the plus set temperature T2 are reached, frost on the heat collector is almost lost. Heat collecting operations are controllably made again.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solar heat collecting device comprising a heat collecting circuit that collects solar heat and atmospheric heat, and a hot water heating circuit that heats water using the collected heat. This relates to heat collection operation control at low outside temperatures.

Structure of a conventional example and its problems A conventional solar heat collecting device of this type is shown in FIG. 1
is a collector that evaporates refrigerant using solar and atmospheric heat;
2 is an accumulator, 3 is a compressor, 4 is a condenser for condensing the refrigerant, 5 is a temperature-type expansion valve, 6 is a temperature-sensitive tube, and 7 is a capillary tube.

Further, 8 is a heat exchanger that absorbs heat released from the refrigerant from the condenser 4, 9 is a pump, and 10 is a heat storage tank.

In the above configuration, in order to prevent liquid return operation of the compressor at low outside temperatures, an outside temperature sensor 11 is provided, and an operation control is used in which the heat collection operation is turned on and off according to the set temperature. The above method does not include the installation conditions of the outside temperature sensor, the amount of solar radiation, and the weather conditions such as outside air wind speed, so it is indirect and cannot be said to be a sufficient method for detecting the prevention of liquid backflow in the compressor. . As a result, there was a problem in that even though heat collection operation was possible, heat collection operation was not performed and the temperature of the hot water supply in the heat storage tank could not be increased.

OBJECT OF THE INVENTION The present invention solves the problems of the prior art, and provides a system that prevents fluid from returning to the compressor during low outside temperatures or when the collector is frosted by directly detecting the temperature of the refrigerant circulation closed circuit. The purpose of this project is to improve the reliability of the system, extend the heat collection operation time, prevent a drop in operating efficiency at low outside temperatures, and increase the temperature of the hot water supply.

Structure of the Invention To achieve this object, the present invention consists of a heat collection circuit consisting of a heat collector, an accumulator, a compressor, a condenser, and a pressure reducing device, a heat exchanger pump that exchanges heat with the condenser, and a heat storage tank. A solar heat collection device consisting of a hot water heating circuit is equipped with a temperature sensor that detects the temperature at the collector inlet, and a control device that stops and restarts the heat collection operation when the collector inlet temperature reaches negative or the glass's set temperature. It is arranged. Here, the reason why the heat collection operation is returned to a positive set temperature is to allow natural defrosting of the heat collector.

With this configuration, the liquid return prevention detection of the compressor is performed directly at the collector inlet temperature, which is a closed refrigerant circulation circuit, when the outside temperature is low or the collector is frosted, and the collector inlet temperature is set to be negative. If it is below this value, the heat collection operation will be stopped. After the operation is stopped, there is a temporary rise in temperature to the positive side at the collector inlet due to the leakage of refrigerant from the pressure reducing device from the high pressure side to the low pressure side. Since the increase in temperature at the heater inlet occurs regardless of the completion of natural defrosting of the heat collector, it is not detected as a dead zone, but is detected after a certain period of time has elapsed, and control is performed to determine whether to return to heat collection operation.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1
2 is a temperature sensor that detects the inlet temperature of the heat collector 10 and has two set temperatures T1 and T2, negative and positive; 13 is a control device that detects the output of the temperature sensor 12 and produces a preset predetermined output; be. Note that the same members as in FIG. 1 are given the same numbers, and therefore their explanations will be omitted.

Next, the operation of the solar heat collecting device having the above configuration will be explained.

The high-temperature, high-pressure refrigerant gas compressed by the compressor a flows into the condenser 4, and uses the heat of condensation to heat and raise the temperature of the low-temperature water sent by the pump 9 of the hot water heating circuit, and stores it in the heat storage tank 10. On the other hand, the refrigerant that has been liquefied by being deprived of the heat of condensation flows into the thermostatic expansion valve 5 and the capillary tube 7 and is depressurized into the heat collector 1.
It flows into the air, absorbs solar heat and atmospheric heat, evaporates into gas, and returns to the compressor 3 through the Akie emulator 2.

When the outside temperature decreases or when frost forms on the heat collector 1, the heat collector inlet temperature decreases, and the temperature sensor 1
2 reaches the negative set temperature T1, the heat collecting operation is stopped in order to prevent the compressor 3 from returning to liquid. After the heat collection operation is stopped, the temperature at the inlet of the heat collector rises to above the positive set temperature of 12 for a short period of time due to the leakage of refrigerant from the high pressure to the low pressure in the pressure reducing device, and then returns to the outside temperature. Getting closer. After a certain period of time has passed after the heat collection operation is stopped, the control device 14 detects the output of the temperature sensor 12, and if the positive set temperature is 12 or higher, the frost on the heat collector is almost gone and the heat is collected again. Controls the start of operation.

During the above operation, the compressor's liquid return operation is prevented by detecting the collector inlet temperature, and the collector inlet temperature is set to a positive value after a certain period of time has passed after the heat collector operation is stopped. As this is carried out at the above times, reliability is improved by directly detecting the temperature of the refrigeration cycle regardless of complex outside weather conditions in order to prevent liquid back-up, and recovery of heat collection operation is possible due to frost formation on the collector. In this case, operation can be restarted from a state where no frost has formed on the heat collector #1, and frequent turning on and off of the compressor can be avoided, thereby preventing a decrease in operating efficiency.

Effects of the Invention The present invention provides a solar heat collection system consisting of a heat collection circuit consisting of a heat collector, an achiemulator, a compressor, and a pressure reducing device, and a hot water heating circuit, which has two set temperatures T, negative and positive.
1. A temperature sensor with T2 is installed at the collector inlet, and when the collector inlet temperature TE is TE≦T1, the heat collection operation is stopped, and a dead zone of the collector inlet temperature is provided for a certain period of time after the operation is stopped. After that, when the natural defrosting of the heat collector is almost completed and the temperature reaches TE≧T2, the heat collection operation is controlled to resume, thereby improving the reliability of preventing liquid return to the compressor and preventing frequent compressor operation. This prevents deterioration in operating efficiency due to on/off switching, and increases the temperature of hot water supply by extending the heat collection operation time at low outside temperatures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional solar heat collecting device, FIG. 2 is a block diagram of a solar heat collecting device according to an embodiment of the present invention, and FIG. 3 is a time-collection diagram of the solar heat collecting device. It is a heating device inlet temperature characteristic diagram. 1... Heat collector, 2... Accumulator, 3... Compressor, 4... Condenser, 5...
... Temperature expansion valve, 12 ... Temperature sensor, 13 ... Control device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 1 Figure 2

Claims (1)

[Claims] (1) Consisting of a heat collection circuit consisting of a heat collector, an accumulator, a compressor, a condenser, and a pressure reducing device, and a hot water heating circuit consisting of a heat exchanger that exchanges heat with the condenser, a pump, and a heat storage tank, the negative and A temperature sensor having two positive set temperatures T1 and T2 is disposed at the collector inlet, and when the collector inlet temperature TE is TE≦T1, the heat collection operation is stopped, and when TE≧T2, the heat collection operation is started. A solar heat collecting device equipped with a control device that enables recovery. (b) The solar heat collecting device according to claim 1, wherein the positive set temperature T2 is detected after a certain period of time has passed after the heat collecting operation is stopped.