JPS61213554A - Refrigerant ratio variable controller for refrigeration cycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for varying the concentration of a refrigerant circulating in a compression type refrigeration cycle using a non-azeotropic mixed refrigerant.

BACKGROUND OF THE INVENTION A conventional refrigeration cycle using a non-azeotropic mixed refrigerant was purchased as shown in FIG. 6, for example, as shown in Japanese Patent Laid-Open No. 59-5942.

In the figure, 1 is a compressor, and a condenser 2 is on the discharge side.
is connected. 3 is a fractionator, and a first throttle device 4
It is connected to the outlet side of the condenser 2 via. Further, a conduit 5 branches between the outlet of the condenser 2 and the first throttle device 4, and this conduit 5 is connected to a second throttle device 7 via a first electromagnetic valve 6.

The gas reservoir side of the fractionator 3 is connected to the inlet side of the liquid receiver 9 via the second solenoid valve 8, and the liquid reservoir side is connected to the liquid receiver 9 via the second throttle device 7. Condensing heat exchanger 1 installed
Connected to the inlet side of 0.

Further, the outlet side of the condensing heat exchanger 10 is connected to an evaporator 11 and then to a compressor 1. Furthermore, the outlet side of the liquid receiver 9 is connected via a third electromagnetic valve 12 and a third throttle device 13 to the middle of a pipe connecting a condensing heat exchanger 10 and an evaporator 11.

The operation of this cycle configured as above will be explained.

First, during normal cooling operation, the first solenoid valve 6 is open and the second and third solenoid valves 8.12 are closed, so that only the high boiling point components are circulated in the cycle, and the low boiling point components are the receiving liquid. The high-boiling point component gas accumulated in the container 9 as a liquid and compressed by the compressor 1 is condensed in the condenser 2 and passed through the conduit 5 to the second throttle device 7.
The pressure is reduced in the evaporator 11 through the condensing heat exchanger 10
It becomes a gas and returns to the compressor 1, where a normal low temperature is obtained.

Next, during rapid cooling operation, the first and second solenoid valves 6.8 are in the same state as during normal operation, and the third solenoid valve 12 is opened, and the low boiling point component stored in the liquid receiver 9 is released under high pressure. The pressure is reduced by the third throttling device 13 and the refrigerant is discharged into the refrigeration cycle, and the non-azeotropic mixed refrigerant of high boiling point components and low boiling point components circulates through the refrigeration cycle in the same circuit as during normal cooling operation.

Also, when returning from rapid cooling operation to normal cooling operation, the first
, the third solenoid valve 6.12 closes and the second solenoid valve 8 opens, so that the non-azeotropic mixed refrigerant gas compressed by the compressor 1 is
It is condensed in the condenser 2, depressurized in the first throttle device 4, and enters the fractionator 1a. Due to the pressure reducing action of the first throttling device 4, only the high-boiling point components of the non-azeotropic mixed refrigerant that entered the fractionator 3 are liquefied and accumulated in the lower liquid reservoir side, while the low-boiling point components are converted into gas in the upper part. The high-boiling components are separated so as to accumulate on the gas reservoir side, and the liquefied high-boiling components are reduced in pressure by the second expansion device 7, enter the condensing heat exchanger 10, evaporate to some extent, and then pass through the evaporator 11 to the compressor. Enter 1.

Since the second electromagnetic valve 8 is open, the low boiling point component in the gaseous state enters the liquid receiver 9, where it is heat exchanged with the condensing heat exchanger 10, and is condensed and stored as a liquid. It accumulates in In this way, the high boiling point component and the low boiling point component are separated, and when the liquid receiver 9 is filled with the low boiling point component, the first solenoid valve 6 opens and the second and third solenoid valves 8.12 close. As a result, the cycle returns to normal cooling operation.

Problems to be Solved by the Invention However, with the above configuration, there is a problem in that the refrigerant concentration cannot be controlled to vary in order to perform capacity control that matches the cooling load.

The present invention solves the above problems by providing a control device that freely varies the ratio of low boiling point components of the refrigerant circulating in the non-azeotropic mixed refrigerant cycle, thereby controlling the capacity in accordance with the cooling load. The purpose is to do something.

Means for Solving the Problem In order to solve this problem, the present invention provides a flow control valve and a throttling device on the outlet side of the liquid receiver that stores the refrigerant with low boiling point components separated by the fractionator. , a temperature detection means connected in the middle of the pipe connecting the condensing heat exchanger and the evaporator, and a temperature detection means for detecting the temperature of the object to be cooled and converting it into an electric signal, and an electric signal of the temperature set value and the temperature. Comparing means for comparing and determining the electrical signals output from the detecting means and outputting a control signal;
a storage means storing an output mode for controlling the valve opening degree of the flow control valve; and a transition means for sequentially transmitting a signal to the storage means based on a control signal output from the comparison means;
A control device is provided for varying the ratio of low boiling point components of the refrigerant circulating in the non-azeotropic mixed refrigerant cycle, which is constituted by an output means that changes the valve opening of the flow control valve according to the output mode of the storage means. .

Effect: With the above configuration, the present invention changes the valve opening of the flow rate control valve according to the difference between the temperature of the object to be cooled and the set temperature, and changes the ratio of low boiling point components during the cycle, thereby achieving cooling according to the load. It is also possible to easily maintain the temperature of the object to be cooled almost constant.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 to 5.

First, FIG. 5 shows a cycle using a non-azeotropic mixed refrigerant.

In the figure, in the refrigeration cycle, the third solenoid valve 12 is replaced with the flow rate control valve 14 in the conventional cycle, and opening and closing of the third solenoid valve 12 corresponds to full opening and full opening of the flow rate control valve 14.

Furthermore, a temperature detector (thermistor) 15 is attached to the evaporator 11 to detect the temperature of the object to be cooled, and a microcomputer (hereinafter referred to as a microcomputer) determines and controls the signal from the thermistor 15 and the signal of the set temperature. It has a structure in which the flow control valve 14 is controlled.

Next, in FIG. 1, the control circuit includes a microcomputer 16 that controls the entire refrigerator, a thermistor 15 that detects the temperature Tr, a temperature detection circuit 17, a resistance circuit 18 that outputs the set temperature T1, and the flow control valve 14. It is composed of a step motor 19 that controls the valve opening degree.

Here, the block diagram shown in FIG. 2 and the control circuit shown in FIG. 1 will be explained.

The resistance circuit 18 that outputs the set temperature T1 shown in FIG. 1 corresponds to the temperature set value shown in FIG.
5. The temperature detection circuit 17 corresponds to the temperature detection means in Fig. 2, and the microcomputer 16 in Fig. 1 compares the electric signal of the temperature setting value shown in Fig. 2 with the electric signal output from the temperature detection means. a comparison means for determining and comparing control signals and outputting a control signal; a storage means for storing first to third output modes for controlling the valve opening of the flow rate regulating valve 14; This corresponds to a transition means that sequentially transmits signals to the storage means based on the output control signals. Furthermore, the step motor 19 in FIG. 1 corresponds to the output means in FIG.

In the above configuration, the configuration and operation of the control circuit that changes the ratio of refrigerant with a low boiling point component in the refrigeration cycle by controlling the valve opening of the flow rate regulating valve 14 according to the set temperature and the temperature of the object to be cooled is shown in Figure 3. , will be explained with reference to FIG.

First, in normal cooling operation, the first solenoid valve 4 is closed, the second solenoid valve 8 is opened, and the flow control valve 14 is fully opened. In this state, 100 inches of refrigerant with a high boiling point component is circulating in the cycle.

Here, the temperature Tv is detected by the thermistor 15, and when the detected temperature Tv is higher than the set temperature T1, the microcomputer 16
The arithmetic circuit outputs a control signal to the step motor 19 so that the valve opening degree is 1 (fully open) in the first output mode of the storage circuit. In this state, the ratio of high boiling point component and low boiling point component refrigerant circulating through the cycle is set to 1:1.

Next, when the detected temperature Tv is equal to the set temperature T1, the arithmetic circuit of the microcomputer 16 outputs a control signal to the step motor 19 so that the valve opening degree is 2 (half open) in the second output mode of the memory circuit. Therefore, the flow control valve 14 is in a half-open state, and the ratio of high boiling point components and low boiling point components circulating in the cycle is 2:1.

Furthermore, when the detected temperature fiTv is lower than the set value T1, the arithmetic circuit of the microcomputer 16 sends a control signal to the step motor 19 so that the valve opening is 3 (total -P#) in the third output mode of the memory circuit. Output. Therefore, the flow rate control valve 14 is fully closed, and only the high boiling point components of the refrigerant circulate in the cycle, returning to normal operation.

As described above, according to this embodiment, the cooling load is determined by detecting the temperature of the object to be cooled and comparing it with the set temperature,
The refrigerant ratio can be variably controlled to match the load.

In this embodiment, the step motor 19 performs three-stage flow control, but the same effect can be obtained by performing stepless flow control depending on the magnitude of the difference between the set temperature and the detected temperature.

Effects of the Invention As described above, the present invention determines the cooling load by detecting the temperature of the object to be cooled and comparing it with the set temperature, and controls the valve opening of the flow rate control valve to reduce the low temperature during the refrigeration cycle. The ratio of the boiling point refrigerant can be freely changed, and the operation can be performed in accordance with the load.

[Brief explanation of the drawing]

Fig. 1 is a control circuit diagram according to an embodiment of the present invention, Fig. 2 is a block diagram thereof, Fig. 3 is a flowchart thereof, and Fig. 4 shows the valve opening degree of the flow control valve according to temperature changes by the control device. The characteristic diagram, FIG. 5 is a refrigeration cycle diagram of one embodiment, and FIG. 6 is a refrigeration cycle diagram of a conventional example. 1... Compressor, 2... Condenser, 3...
... Fractionator, 9 ... Receiver, 1o ...
・・Condensing heat exchanger, 11・・Evaporator, 14・
...Flow control valve, 16...Thermistor,
16...Microcomputer, 17...Temperature detection circuit, 18...Resistance circuit, 19...Step motor. Name of agent: Patent attorney Toshio Nakao and 1 other person15
--Ichijo-Misuku No. 1 Figure 16--Microcomputer 17--Rinsha concave, path, 13-m-Resistance circuit! ? ---Step motor Fig. 2 Fig. 3 Fig. 4
Riki t /6---Rukiichi Sujiri Saki! d(
microcomputer) and -11 second solenoid valve

Claims (1)

[Claims] A refrigeration cycle is constructed by connecting a compressor, a condenser, a throttle device, and an evaporator in sequence, and uses a non-azeotropic mixed refrigerant consisting of a low-boiling point component and a high-boiling point component, and a first throttle is installed on the outlet side of the condenser. A fractionator that fractionates the non-azeotropic mixed refrigerant into a low boiling point component and a high boiling point component via a device, and a low boiling point component is stored on the gas reservoir side of the fractionator via a solenoid valve. A condensing heat exchanger is installed in each of the liquid receivers, and a temperature detection means for detecting the temperature of the object to be cooled and converting it into an electric signal is provided. a comparison means for comparing and determining the electric signal outputted from the temperature detection means and outputting a control signal, and a storage means for storing an output mode for controlling the valve opening of the flow rate regulating valve;
A transition means for sequentially transmitting a signal to the storage means based on a control signal output from the comparison means, and an output means for changing the valve opening degree of a flow rate control valve for the low boiling point component refrigerant according to the output mode of the storage means. Refrigerant cycle refrigerant ratio variable control device.