JPH0221493B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a solar heat pump that utilizes solar heat as a heat source for a gas compression heat pump by flowing a fluorocarbon refrigerant directly through a solar collector. Regarding control method.

(Prior Art) In a heat pump that utilizes solar heat, the amount of solar radiation changes rapidly, so the load on the evaporator changes rapidly and is large. Therefore, a liquid pump type heat pump having only a flow rate regulator and a flow rate adjustment valve that operate to maintain a constant liquid level in a low-pressure liquid receiver has insufficient operation.

In other words, in the case of a liquid pump type heat pump, for example, in response to a sudden decrease in solar radiation, if only the flow rate control is performed to keep the liquid level in the low pressure receiver constant, and the capacity of the compressor is not controlled, the low pressure receiver The fluorocarbon refrigerant in the liquid container self-evaporates, and as a result, the liquid pump sucks in the fluorocarbon gas, causing large vibrations and noise, making it inoperable.

In addition, in heat pumps that utilize solar heat, the system from the flow rate adjustment valve to the solar collector is long, so there is a large time delay that often impedes operation.

(Problems to be Solved by the Invention) The present invention eliminates the above-mentioned drawbacks of the prior art and provides stable and efficient operation for systems with severe load fluctuations, large dead times, and large time delays. The purpose is to obtain a possible control method for

[Structure of the invention]

(Means for Solving the Problems) The present invention is a method for controlling a liquid pump type solar heat pump that uses solar heat as a heat source for a gas compression type heat pump by directly circulating a fluorocarbon-based refrigerant through a solar collector. The signal from the liquid level detector of the low-pressure liquid receiver operates the flow rate regulator to operate the flow rate adjustment valve, and at the same time, a signal of the amount of solar radiation or the temporal change rate of the amount of solar radiation is given to the capacity controller of the compressor to perform compression. It also controls the capacity of the machine.

Note that the capacity of the compressor can also be controlled by also giving a signal from the pressure detector of the low-pressure liquid receiver to the capacity regulator of the compressor.

(Function) The liquid level of the low-pressure liquid receiver is controlled by operating the flow regulator and operating the flow rate adjustment valve based on the signal from the liquid level detector of the low-pressure liquid receiver, and
By giving a signal of the amount of solar radiation or the temporal change rate of the amount of solar radiation to the capacity regulator of the compressor, the operation of the liquid pump can be maintained appropriately in the face of sudden changes in the amount of solar radiation.

(Example) An example of implementation of the present invention will be explained with reference to the drawings.

The high-temperature, high-pressure fluorocarbon gas refrigerant compressed by the compressor 1 releases heat by heating hot water in the water heater 2 and is condensed and liquefied, and the refrigerant liquid from the water heater 2 is depressurized in the flow rate regulating valve 3. The liquid becomes a low-temperature, low-pressure liquid and is temporarily stored in the low-pressure liquid receiver 12. Then, the liquid is sent to the solar collector 4 by the liquid pump 14, absorbs solar heat, evaporates and gasifies, and once flows into the low-pressure liquid receiver 12 through the gas pipe 16.
The gas is then sucked into the compressor 1 through the gas suction pipe 10. The flow rate regulator 11 issues a command to the flow rate regulating valve 3 so that the liquid level in the low-pressure liquid receiver 12 measured by the liquid level detector 13 becomes constant.

A capacity regulator 1 of the compressor according to the amount of solar radiation measured by the pyranometer 9 or the temporal change rate of the amount of solar radiation.
7 issues a command to the compressor 1 so that the pressure in the low pressure liquid receiver 12 measured by the pressure detector 15 becomes constant.

Furthermore, when the amount of solar radiation changes rapidly, the capacity regulator 17 can freely change the setting value of the pressure of the low-pressure liquid receiver 12, giving priority to the above-mentioned normal control. .

In addition, the flow rate regulator 11 and the compressor capacity regulator 17
The same regulator can also serve as both.

〔Effect of the invention〕

The present invention directly measures the amount of solar radiation when controlling a liquid pump solar heat pump that uses solar heat as a heat source for a gas compression heat pump by flowing a fluorocarbon refrigerant directly through a solar collector.
This assists the liquid level adjustment function of the low-pressure liquid receiver in the liquid pump type control method in which information on the amount or its rate of change over time (amount of variation) is given to the flow rate regulator, enabling stable and efficient operation. It became. Furthermore, the time constant of a pyranometer is usually very small, on the order of several seconds, and by directly measuring this and using this information for control, it is possible to compensate for the time delay factor in the control method.

[Brief explanation of drawings]

The figure is a flow sheet diagram of an example of implementing the control method of the present invention. 3...Flow rate adjustment valve, 4...Solar collector, 9
...Pyranometer, 11...Flow rate regulator, 12...Low pressure liquid receiver, 13...Liquid level detector, 14...Liquid pump, 15...Pressure detector, 17...Capacity regulator.

Claims (1)

[Claims] 1. A high-pressure fluorocarbon-based gas refrigerant discharged from a compressor is liquefied in a condenser, the pressure of the liquid refrigerant is reduced by a flow rate adjustment valve, and the liquid refrigerant is temporarily stored in a low-pressure liquid receiver. In the liquid pump type solar heat pump method, in which the gas refrigerant is passed directly to the solar collector by a pump and the gas refrigerant that has absorbed heat and evaporated is sucked into the compressor, the flow rate regulator is operated by the signal from the liquid level detector of the low-pressure liquid receiver to control the flow rate. A liquid pump type characterized in that the flow rate of refrigerant is controlled by operating a regulating valve, and the capacity of the compressor is controlled by giving a signal of the amount of solar radiation or the temporal change rate of the amount of solar radiation to the capacity regulator of the compressor. Control method for solar heat pump. 2. A liquid pump type solar heat pump according to claim 1, wherein the capacity of the compressor is controlled by giving a signal from a pressure detector of a low-pressure liquid receiver to a capacity regulator of the compressor. control method.