JPS6266065A - Liquid-return preventive method of refrigerator - 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 Application of the Invention] The present invention relates to a method for preventing liquid return in a refrigeration system, and more particularly to a method for preventing liquid return to a compressor by determining the humidity of suction gas.

[Background of the invention]

In refrigeration equipment, liquid return sometimes occurs due to sudden changes in the refrigeration load, so it is necessary to take measures to prevent liquid return. As a conventional liquid return prevention method, for example, Kobe Steel Technical Report R&D Vol. 2
As disclosed on page 23 of B, No. 1, a liquid sensor is provided to detect the temperature of the discharged gas, and when the discharged gas temperature decreases when the discharged gas pressure is constant (the discharged gas temperature decreases when the liquid returns). There is a method of preventing the liquid from returning to the pressurizer by issuing five alarms based on the signal from the sensor. However, this method has good responsiveness when the discharge gas temperature continues to decrease, but if the liquid returns instantaneously, the discharge gas temperature may not decrease, so the response is poor. There is a problem with delays.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for preventing liquid return in a refrigeration system that can quickly respond and prevent liquid return whether liquid return occurs continuously or instantaneously.

[Summary of the invention]

The liquid return prevention method of the present invention includes disposing an electric coil and a temperature sensor in the suction pipe of a refrigeration cycle, and detecting a temperature change of the electric coil with the temperature sensor, thereby preventing moisture in the refrigerant gas flowing in the suction pipe. This system is designed to prevent liquid from returning to the compressor by determining the opening degree of the expansion valve, stopping the refrigeration cycle, etc.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 shows a refrigeration cycle diagram of a refrigeration unit in which the liquid return prevention method according to the present invention is implemented, and these devices include a 1-digit compressor, 2 a condenser, 3 an expansion valve, and 4 an evaporator. The pipes are connected to form a refrigeration cycle. VC in the suction pipe 5 of this refrigeration cycle is connected to an electric coil 6 and a temperature leech sensor 7 that detects the temperature at both ends of the electric coil 6.
A and 7B are arranged. The electric coil 6 power source 8
It is connected to the.

Next, the operation of the liquid return prevention method according to the present invention will be explained.

When refrigerant gas with droplets mixed in, so-called wet refrigerant gas, flows into the suction pipe 5, the heat of the electric coil 6 is consumed to evaporate the droplets, so the temperature rise V'i gradually decreases. come. Since this drop rate is proportional to the amount of droplets, that is, the wetness, if the relationship between the drop rate and the wetness is calibrated in advance and understood as a characteristic as shown in Figure 2, it is possible to use a temperature sensor. From the temperature changes detected at 7A and 7B, it can be determined that the refrigerant gas is 19 degrees Celsius, and depending on the degree of humidity, the opening degree of the expansion valve 3 is adjusted, the refrigeration cycle is stopped, etc.

Therefore, in the liquid return prevention method according to the present invention, liquid return can be controlled by determining the wetness of the refrigerant gas from the temperature change of the electric coil 6. Therefore, when liquid return occurs continuously, instantaneous liquid return is possible. It is possible to quickly respond to any situation that occurs.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to respond quickly and prevent liquid return, whether it occurs continuously or instantaneously.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of a refrigeration system in which the liquid return prevention method of the present invention is implemented, and FIG. 2 is a characteristic diagram showing the relationship between the temperature change rate of the electric coil and the wetness of the refrigerant gas. 1... Compressor 2... Condenser 3... Expansion valve 4... Evaporator 5... Suction piping 6... Electric coils 7A, 7B... Temperature sensor. Built 10 years old

Claims (1)

[Claims] In a refrigeration system in which a refrigeration cycle is formed by a compressor, a condenser, an expansion valve, an evaporator, etc., an electric coil and a temperature sensor are arranged in a suction pipe of the refrigeration cycle,
The humidity level of the refrigerant gas flowing in the suction pipe is determined by detecting the temperature change of the electric coil with the temperature sensor, and the opening degree of the expansion valve is adjusted, the refrigeration cycle is stopped, etc. Method for preventing liquid return in refrigeration equipment.