A multi-temperature zone refrigerator system based on a multi-ejector device and a working method thereof

Abstract

The present invention relates to a multi-temperature zone refrigerator system and operating method based on a multi-ejector device. The system structure is as follows: the compressor outlet is connected to the inlet of a first three-way valve through a condenser, the first outlet of the first three-way valve is connected to the first inlet of a first ejector, and the first ejector outlet is connected to the inlet of the compressor through a first evaporator in turn; the second outlet of the first three-way valve is connected to the first inlet of a second ejector, the second ejector outlet is connected to the inlet of a gas-liquid separator, the liquid phase outlet of the gas-liquid separator is connected to the inlet of the second three-way valve, the first outlet of the second three-way valve is connected to the second inlet of the second ejector in turn through a throttle valve and a third evaporator; the gas phase outlet of the gas-liquid separator is connected to the first inlet of the third three-way valve, the second outlet of the second three-way valve is connected to the second inlet of the third three-way valve through the second evaporator, and the outlet of the third three-way valve is connected to the second inlet of the first ejector. This achieves a single cycle with multiple evaporation pressures and reduces irreversible losses in the system.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration technology, and in particular to a multi-temperature zone refrigerator system based on a multi-ejector device and a working method. Background Art

[0002] The refrigeration cycle systems currently used in multi-temperature zone refrigerators can be broadly categorized as: a) single-cycle; b) compressor dual-cycle; c) separate dual-cycle; and d) bypass dual-cycle. In traditional multi-temperature zone refrigerators, the evaporation temperature of the evaporators in each compartment is the same, the same as that in the freezer compartment. Because the freezer compartment's temperature is very low, the evaporation temperatures of the evaporators in other compartments are also low. This results in large heat exchange temperature differences, causing significant irreversible losses and inaccurate temperature control. Irreversible losses refer to unavoidable losses caused by heat transfer temperature differences, friction, and other factors. These losses refer to the loss of available energy. For example, a refrigerant with an evaporation temperature of -26°C can achieve a low-temperature environment of -18°C. However, traditional single-cycle multi-temperature refrigerators not only use a refrigerant with an evaporation temperature of -26°C to achieve a low-temperature environment of -18°C, but also directly use the refrigerant at this temperature to achieve low temperatures of -6°C, 0°C, and 5°C, increasing the available energy loss. The dual-circuit compressor system used in traditional multi-temperature zone refrigerators allows for independent dual temperature control, but the available compressors are smaller, reducing efficiency, increasing costs, and complicating the system. The discrete dual-circuit system employed by traditional multi-temperature zone refrigerators cannot simultaneously provide cooling to multiple evaporators, resulting in unstable temperature control. In a bypass dual-circuit system, connecting the bypass circuit to the freezer evaporator fails to address the significant irreversible losses. Connecting the bypass circuit to the refrigerator evaporator results in the evaporation temperature in both compartments being the same most of the time, resulting in significant irreversible losses. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the present invention provides a multi-temperature zone refrigerator system and working method based on a multi-ejector device, the purpose of which is to achieve a single cycle with multiple evaporation pressures, reduce the heat exchange temperature difference, and reduce irreversible losses.

[0004] The technical solution adopted in the present invention is as follows:

[0005] On one hand, the present invention provides a multi-temperature zone refrigerator system based on a multi-ejector device, comprising a compressor, a condenser, a first three-way valve, a first ejector, a second ejector, a third three-way valve, a first evaporator, a second evaporator, a third evaporator, a second three-way valve, a throttle valve, and a gas-liquid separator. The connection structure along the refrigerant flow direction is as follows:

[0006] The outlet of the compressor is connected to the inlet of the first three-way valve through the condenser, the first outlet of the first three-way valve is connected to the first inlet of the first ejector, and the outlet of the first ejector is connected to the inlet of the compressor through the first evaporator in turn;

[0007] The second outlet of the first three-way valve is connected to the first inlet of the second ejector, the outlet of the second ejector is connected to the inlet of the gas-liquid separator, the liquid phase outlet of the gas-liquid separator is connected to the inlet of the second three-way valve, and the first outlet of the second three-way valve is connected to the second inlet of the second ejector in sequence through the throttle valve and the third evaporator;

[0008] The gas phase outlet of the gas-liquid separator is connected to the first inlet of the third three-way valve, the second outlet of the second three-way valve is connected to the second inlet of the third three-way valve through the second evaporator, and the outlet of the third three-way valve is connected to the second inlet of the first ejector.

[0009] Further technical solutions are:

[0010] The condenser is an air-cooled condenser.

[0011] On the other hand, the present invention provides a working method of the multi-temperature zone refrigerator system based on the multi-ejector device. According to the loads of the three temperature zones corresponding to the first evaporator, the second evaporator and the third evaporator, the refrigerant flow entering the first ejector, the second ejector and the first evaporator, the second evaporator and the third evaporator is adjusted through the first three-way valve and the second three-way valve to achieve the adjustment of the cooling capacity of the three temperature zones.

[0012] Further technical solutions are:

[0013] The second ejector is used to increase the refrigerant pressure in the third evaporator to the refrigerant pressure in the gas-liquid separator and the second evaporator.

[0014] The first ejector is used to increase the pressure of the gas-phase refrigerant in the second evaporator and the gas-liquid separator to the refrigerant pressure in the first evaporator.

[0015] The evaporation temperature of the third evaporator is -26 to -23°C.

[0016] The evaporation temperature of the second evaporator is -12 to -8°C.

[0017] The evaporation temperature of the first evaporator is -4 to -1°C.

[0018] The beneficial effects of the present invention are as follows:

[0019] This application realizes a single cycle with multiple evaporation pressures, and uses an ejector to divert the refrigerant in a low-pressure state to a medium-pressure state, thereby increasing the suction pressure of the compressor, reducing the power consumption of the compressor, reducing throttling losses, and improving the efficiency of the entire system. It also improves the operating conditions of the air-conditioning system in a high-temperature environment and provides new ideas for the design of multi-temperature refrigerators and multi-temperature systems.

[0020] The present invention also specifically includes the following advantages:

[0021] 1) A single cycle is achieved with small irreversible losses.

[0022] Although the present invention is a single-circulation system, the heat transfer temperature difference between each evaporator in the system and each corresponding temperature zone (chamber) of the refrigerator is small, thereby reducing irreversible losses.

[0023] 2) Accurate control of cooling capacity and temperature is achieved.

[0024] In the present invention, precise control of temperature and cooling capacity is mainly achieved through adjustment of two three-way valves. When the load in a certain room of the refrigerator changes, the refrigerant flow in different pipelines is adjusted by the three-way valve to achieve cooling capacity and temperature control in each evaporator.

[0025] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the system structure of an embodiment of the present invention.

[0027] In the figure: 1. compressor; 2. condenser; 3. first three-way valve; 4. first ejector; 5. second ejector; 6. third three-way valve; 7. first evaporator; 8. second evaporator; 9. third evaporator; 10. second three-way valve; 11. throttle valve; 12. gas-liquid separator. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are described below with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the embodiment of the present application provides a multi-temperature zone refrigerator system based on a multi-ejector device, including a compressor 1, a condenser 2, a first three-way valve 3, a first ejector 4, a second ejector 5, a third three-way valve 6, a first evaporator 7, a second evaporator 8, a third evaporator 9, a second three-way valve 10, a throttle valve 11 and a gas-liquid separator 12. The connection structure along the refrigerant flow direction is:

[0030] The outlet of the compressor 1 is connected to the inlet of the first three-way valve 3 through the condenser 2, the first outlet of the first three-way valve 3 is connected to the first inlet of the first ejector 4, and the outlet of the first ejector 4 is connected to the inlet of the compressor 1 through the first evaporator 7 in turn;

[0031] The second outlet of the first three-way valve 3 is connected to the first inlet of the second ejector 5, the outlet of the second ejector 5 is connected to the inlet of the gas-liquid separator 12, the liquid phase outlet of the gas-liquid separator 12 is connected to the inlet of the second three-way valve 10, and the first outlet of the second three-way valve 10 is connected to the second inlet of the second ejector 5 through the throttle valve 11 and the third evaporator 9 in sequence;

[0032] The gas phase outlet of the gas-liquid separator 12 is connected to the first inlet of the third three-way valve 6 , the second outlet of the second three-way valve 10 is connected to the second inlet of the third three-way valve 6 through the second evaporator 8 , and the outlet of the third three-way valve 6 is connected to the second inlet of the first ejector 4 .

[0033] Specifically, the condenser 2 is an air-cooled condenser.

[0034] An embodiment of the present application also provides a working method of the multi-temperature zone refrigerator system based on the multi-ejector device. According to the loads of the three temperature zones corresponding to the first evaporator 7, the second evaporator 8 and the third evaporator 9, the refrigerant flow entering the first ejector 4, the second ejector 5 and the first evaporator 7, the second evaporator 8 and the third evaporator 9 is adjusted through the first three-way valve 3 and the second three-way valve 10 to achieve the adjustment of the cooling capacity of the three temperature zones.

[0035] The ejector also uses high-pressure fluid to increase the pressure of low-pressure fluid: the second ejector 5 increases the refrigerant pressure in the third evaporator 9 to the refrigerant pressure in the gas-liquid separator 12 and the second evaporator 8. The first ejector 4 increases the gas-phase refrigerant pressure in the second evaporator 8 and the gas-liquid separator 12 to the refrigerant pressure in the first evaporator 7.

[0036] Specifically, the function of the second ejector 5 is to mix the higher-pressure refrigerant from the outlet of the first three-way valve 3 with the lower-pressure refrigerant from the third evaporator 9 to form a medium-pressure refrigerant (greater than the outlet pressure of the third evaporator 9 and less than the outlet pressure of the first three-way valve 3) that enters the gas-liquid separator 12. Similarly, the function of the first ejector 4 is to mix the higher-pressure refrigerant from the outlet of the first three-way valve 3 with the lower-pressure refrigerant from the third three-way valve 6 (the pressure of the gas-phase refrigerant in the gas-liquid separator 12 is equal to that of the second evaporator 8) to form a medium-pressure refrigerant that enters the first evaporator 7, thereby causing the refrigerant pressures in the first evaporator 7, the second evaporator 8, and the third evaporator 9 to decrease in sequence, forming three pressure levels corresponding to the three evaporation temperature levels.

[0037] The present application utilizes an ejector to divert the refrigerant in a low-pressure state to a medium-pressure state, thereby increasing the suction pressure of the compressor, reducing the power consumption of the compressor, reducing throttling losses, improving the efficiency of the entire system, and improving the operation of the compressor under high-temperature conditions.

[0038] The evaporation temperature of the third evaporator 9 is -26 to -23°C during operation.

[0039] The evaporation temperature of the second evaporator 8 during operation is -12 to -8°C.

[0040] The evaporation temperature of the first evaporator 7 during operation is -4 to -1°C.

[0041] According to the Carnot cycle principle, efficiency is improved by increasing the evaporation temperature. This increases the system's Carnot cycle efficiency. Evaporation temperature is proportional to evaporation pressure. In this application, the third evaporator 9 has the lowest evaporation pressure, while the second evaporator 8 and the first evaporator 7 have the highest evaporation pressure. Because each evaporation temperature matches the desired cooling load, the heat transfer temperature difference between each evaporator and each refrigerator compartment is reduced, significantly minimizing irreversible losses.

[0042] The precise control of evaporation temperature and cooling capacity in this application is primarily achieved through the regulation of the first and second three-way valves. When the load within a particular compartment (temperature zone) of the refrigerator changes, the three-way valves adjust the refrigerant flow in different pipelines to achieve cooling capacity and temperature control in each evaporator. Those skilled in the art will understand that, while the total refrigerant flow remains constant, adjusting two of the three-way valves can achieve flow control for all evaporators and ejectors.

[0043] Those skilled in the art will understand that the foregoing descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will be able to modify the technical solutions described in the foregoing embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A multi-temperature zone refrigerator system based on a multi-ejector device, characterized in that: The invention comprises a compressor (1), a condenser (2), a first three-way valve (3), a first ejector (4), a second ejector (5), a third three-way valve (6), a first evaporator (7), a second evaporator (8), a third evaporator (9), a second three-way valve (10), a throttle valve (11) and a gas-liquid separator (12), wherein the connection structure along the flow direction of the refrigerant working medium is as follows: The outlet of the compressor (1) is connected to the inlet of the first three-way valve (3) through the condenser (2), the first outlet of the first three-way valve (3) is connected to the first inlet of the first ejector (4), and the outlet of the first ejector (4) is connected to the inlet of the compressor (1) through the first evaporator (7) in turn; The second outlet of the first three-way valve (3) is connected to the first inlet of the second ejector (5), the outlet of the second ejector (5) is connected to the inlet of the gas-liquid separator (12), the liquid phase outlet of the gas-liquid separator (12) is connected to the inlet of the second three-way valve (10), and the first outlet of the second three-way valve (10) is connected to the second inlet of the second ejector (5) in sequence through the throttle valve (11) and the third evaporator (9); The gas phase outlet of the gas-liquid separator (12) is connected to the first inlet of the third three-way valve (6), the second outlet of the second three-way valve (10) is connected to the second inlet of the third three-way valve (6) through the second evaporator (8), and the outlet of the third three-way valve (6) is connected to the second inlet of the first ejector (4).

2. The multi-temperature zone refrigerator system based on the multi-ejector device according to claim 1, characterized in that: The condenser (2) is an air-cooled condenser.

3. A method for operating a multi-temperature zone refrigerator system based on a multi-ejector device according to claim 1, characterized in that: According to the loads of the three temperature zones corresponding to the first evaporator (7), the second evaporator (8) and the third evaporator (9), the refrigerant flow rates entering the first ejector (4), the second ejector (5) and the first evaporator (7), the second evaporator (8) and the third evaporator (9) are adjusted through the first three-way valve (3) and the second three-way valve (10), thereby achieving the adjustment of the cooling capacity of the three temperature zones.

4. The operating method of the multi-temperature zone refrigerator system based on the multi-ejector device according to claim 3, characterized in that: The second ejector (5) is used to increase the refrigerant pressure in the third evaporator (9) to the refrigerant pressure in the gas-liquid separator (12) and the second evaporator (8).

5. The operating method of the multi-temperature zone refrigerator system based on the multi-ejector device according to claim 3, characterized in that: The first ejector (4) is used to increase the pressure of the gas-phase refrigerant in the second evaporator (8) and the gas-liquid separator (12) to the pressure of the refrigerant in the first evaporator (7).

6. The operating method of the multi-temperature zone refrigerator system based on the multi-ejector device according to claim 3, characterized in that: The evaporation temperature of the third evaporator (9) is -26 to -23°C.

7. The operating method of the multi-temperature zone refrigerator system based on the multi-ejector device according to claim 3, characterized in that: The evaporation temperature of the second evaporator (8) is -12 to -8°C.

8. The operating method of the multi-temperature zone refrigerator system based on the multi-ejector device according to claim 3, characterized in that: The evaporation temperature of the first evaporator (7) is -4 to -1°C.

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