CN202133170U - A Liquid Level Control System of a Flooded Refrigeration Unit - Google Patents

Abstract

The utility model discloses a liquid level control system of a flooded refrigerating unit, comprising a flooded evaporator, a compressor, a condenser, an economizer, an injector and a heat exchanger; a flooded evaporator, a compressor , The condenser is connected in sequence, the liquid outlet of the condenser is connected with the liquid inlet of the economizer, the liquid outlet of the economizer is connected with the inlet of the flooded evaporator, the liquid level point interface of the flooded evaporator is connected with the heat exchange The inlet of the ejector is connected, and the high-pressure port, the exhaust port and the ejector port of the ejector are respectively connected with the exhaust port of the economizer, the suction port of the compressor, and the outlet of the heat exchanger. The utility model controls the main throttle valve through the exhaust ejection device of the economizer combined with the superheat degree of the refrigerant at the outlet of the heat exchanger of the ejected pipeline, so as to realize the stable control of the liquid level of the flooded evaporator and the high-efficiency ejection of the evaporator. Oil return, high efficiency, low cost, and great practical value.

Description

A Liquid Level Control System of a Flooded Refrigeration Unit

technical field

The utility model relates to an air-conditioning refrigeration system, in particular to a liquid level control system of a flooded refrigeration unit.

Background technique

Some refrigeration systems, especially for refrigeration systems using flooded evaporators, have the problem of high cost of liquid level control devices. Most of the liquid level control adopts electronic expansion valve, which uses the return air superheat to control the liquid level. However, the return air superheat of the flooded evaporator is very small, and the control is difficult, so that the thermal expansion valve cannot be used, and the electronic expansion valve controls the liquid level. The cost is higher and the control system is more complicated.

Utility model content

The technical problem to be solved by the utility model is to provide a liquid level control system of a flooded refrigerating unit, which solves the problem that the return air superheat of the flooded evaporator is very small and the control is difficult.

The technical scheme of the utility model is:

A liquid level control system of a flooded refrigeration unit, comprising a flooded evaporator, a compressor, a condenser, an economizer, an ejector, and a heat exchanger; the flooded evaporator, compressor, condenser The liquid outlet of the condenser is connected with the liquid inlet of the economizer, the liquid outlet of the economizer is connected with the inlet of the flooded evaporator, the liquid level point interface of the flooded evaporator is connected with the heat exchanger The inlet is connected, and the high-pressure port, the exhaust port and the ejector port of the ejector are respectively connected with the exhaust port of the economizer, the suction port of the compressor, and the outlet of the heat exchanger.

An evaporating oil outlet throttle valve is connected between the liquid level point interface of the flooded evaporator and the inlet of the heat exchanger; an economizer valve is connected between the condenser and the liquid inlet of the economizer. A flow valve; a secondary throttle valve is communicated between the drain port of the economizer and the inlet of the flooded evaporator.

The economizer is selected from a flash tank economizer or a plate-for-plate economizer.

The secondary throttle valve is selected from thermal expansion valve or electronic expansion valve.

The heating medium of the heat exchanger is chilled water, the liquid refrigerant between the condenser and the evaporator, or other media whose temperature is higher than the saturation temperature of the refrigerant at the suction port pressure of the ejector.

The utility model is provided with an economizer, and the intermediate pressure refrigerant vapor generated by the ejector sucks the frozen oil accumulated in the liquid surface of the evaporator into the suction port of the ejector after being heated by the heat exchanger, and then transports them to the compressor together. The suction port enables the refrigerated oil to return from the evaporator to the compressor smoothly, avoiding the failure of the compressor to lose oil, which is more energy-saving and efficient than the oil ejection and return through the exhaust of the compressor commonly used in existing flooded refrigeration units. At the same time, the superheat of the refrigerant in front of the suction port of the ejector is used to control the opening of the secondary throttle valve of the main refrigeration circuit, so the thermal expansion valve can be used instead of the electronic expansion valve, which not only has a better effect, but also can greatly reduce the flooding pressure. unit cost.

Advantage of the utility model:

(1) Adding a heat exchanger on the ejected circuit from the evaporator, using the superheated degree of the subsequent refrigerant to control the throttle valve of the main circuit, the effect is better than that of the current flooded unit used to control the liquid level. Thermally controlled electronic expansion valve with lower cost and more reliable effect;

(2) Through the exhaust of the economizer, the oil is ejected and returned, which not only improves the refrigeration efficiency, but also realizes the large flow of ejected and returned oil, and the economizer can also enhance the oil return, and the effect is obviously better than that of the commonly used compressor exhaust at present. Eject back oil;

(3) The utility model has the advantages of simple structure, low cost, high efficiency, reliability and high practical value, which can make the flooded refrigeration unit more mature and save precious energy for the society.

Description of drawings

Fig. 1 is the system schematic diagram of the utility model.

Detailed ways

See Figure 1, a liquid level control system of a flooded refrigeration unit, including a flooded evaporator 1, a compressor 2, a condenser 3, an economizer 5, an ejector 6 and a heat exchanger 8; The gas outlet 1b of the evaporator 1 is connected with the suction port of the compressor 2, the gas outlet of the compressor 2 is connected with the inlet port of the condenser 3, and the liquid outlet of the condenser 3 is connected with the economizer through the throttle valve 4 of the economizer. The liquid inlet 5a of the economizer 5 is connected, the liquid outlet 5b of the economizer 5 is connected with the inlet 1a of the flooded evaporator 1 through the secondary throttle valve 7, and the liquid level point interface 1c of the flooded evaporator 1 is connected with the evaporation outlet The inlet of the oil port throttle valve 9 is connected, the outlet of the evaporation oil outlet throttle valve 9 is connected with the inlet of the heat exchanger 8, and the high pressure port 6a, the exhaust port 6b and the injection port 6c of the ejector 6 are respectively connected with the economic The exhaust port 5c of the device 5, the suction port of the compressor 2, and the outlet of the heat exchanger 8 are connected. Between the injection port 6c and the heat exchanger 8. Among them, the economizer is a flash tank economizer or a heat exchanger economizer, and the secondary throttle valve is a thermal expansion valve or an electronic expansion valve.

The use principle of the utility model:

The flooded evaporator 1 evaporates the refrigerant, and the evaporated gaseous refrigerant directly enters the compressor 2 from the suction port of the compressor 2, and the incompletely evaporated liquid refrigerant enters the heat exchanger 8 through the throttle valve 9 of the evaporating oil outlet to be heated. It becomes a gaseous refrigerant, and its superheat controls the opening of the secondary throttle valve 7. The ejector 6 utilizes the pressure difference between the intermediate pressure of the economizer 5 and the heating and evaporating pressure of the heat exchanger 8. 6c absorbs the gaseous refrigerant treated by the heat exchanger 8; the subcooled liquid stabilized in the economizer 5 directly enters the flooded evaporator 1 for refrigeration, and the other part of the uncooled gaseous refrigerant in the economizer 5 is treated with the heat exchanger. The gaseous refrigerant enters the compressor 2 together to continue compression.

Claims (4)

1. the tank level control system of a full-liquid type refrigeration unit is characterized in that: comprise flooded evaporator, compressor, condenser, economizer, injector and heat exchanger; Described flooded evaporator, compressor, condenser are communicated with successively; The liquid outlet of condenser is communicated with the inlet of economizer; The leakage fluid dram of economizer is communicated with the import of flooded evaporator; The liquid level point interface of flooded evaporator is communicated with the import of heat exchanger, and the high-pressure mouth of injector, exhaust outlet and ejecting port are communicated with the exhaust outlet of economizer, the air entry of compressor, the outlet of heat exchanger respectively.

2. the tank level control system of full-liquid type refrigeration unit according to claim 1 is characterized in that: be communicated with evaporation oil-out choke valve between the liquid level point interface of described flooded evaporator and the import of heat exchanger; Be communicated with the economizer choke valve between the inlet of described condenser and economizer; Be communicated with the two-step throttle valve between the leakage fluid dram of described economizer and the import of flooded evaporator.

3. the tank level control system of full-liquid type refrigeration unit according to claim 1 is characterized in that: described economizer selects for use flash tank economizer or plate to change economizer.

4. the tank level control system of full-liquid type refrigeration unit according to claim 2 is characterized in that: described two-step throttle valve is selected heating power expansion valve or electric expansion valve for use.

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