Refrigerating system capable of effectively solving frequent start and stop of compressor

Abstract

The utility model provides a refrigerating system capable of effectively solving frequent start and stop of a compressor. The refrigerating system comprises the compressor, a condenser, a liquid storage barrel and a plurality of evaporators which are connected through pipelines. An outlet of the compressor communicates with an inlet of the condenser, an outlet of the condenser communicates with a first inlet of the liquid storage barrel, a first outlet of the liquid storage barrel communicates with inlets of the multiple evaporators, outlets of the multiple evaporators communicate with a second inlet of the liquid storage barrel, and a second outlet of the liquid storage barrel communicates with an inlet of the compressor. A liquid level sensor is arranged on the liquid storage barrel; the plurality of evaporators are connected in parallel between the first outlet and the second inlet of the liquid storage barrel, and refrigerant pumps are respectively arranged on pipelines between the plurality of evaporators and the liquid storage barrel; an expansion valve is arranged on a pipeline between the condenser and the liquid storage barrel, and a pressure sensor is arranged on the condenser. According to the system, sufficient coolant supply can be guaranteed to be provided for the evaporators under various working conditions through the liquid storage barrel, and then the problem of frequent start and stop of the compressor is avoided.

Description

Technical Field

[0001] This utility model relates to the field of vapor compression system technology, specifically a refrigeration system that can effectively solve the problem of frequent compressor start-stop. Background Technology

[0002] A multi-split air conditioning system (VRF) refers to a system that connects multiple indoor units to a single outdoor unit, enabling temperature control of multiple independent rooms. Compared to traditional vapor compression systems, VRF systems are widely used in commercial buildings, public facilities, and residential buildings. Through modular design, the number of operating indoor units can be dynamically adjusted to achieve temperature control in different rooms.

[0003] During operation, multi-split air conditioning systems often experience different load demands from multiple indoor units. This results in some branches requiring more refrigerant while others require less. Consequently, some evaporators may experience insufficient refrigerant supply, and the compressor may frequently start and stop, significantly shortening the compressor's lifespan and reducing system stability. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model provides a refrigeration system that can effectively solve the problem of frequent compressor start-stop.

[0005] The technical solution of this utility model is as follows:

[0006] A refrigeration system that can effectively solve the problem of frequent compressor start-stop, comprising a compressor, a condenser, a liquid receiver and several evaporators connected by pipes;

[0007] The compressor outlet is connected to the condenser inlet, the condenser outlet is connected to the first inlet of the liquid receiver, the first outlet of the liquid receiver is connected to the inlets of several evaporators, the outlets of several evaporators are connected to the second inlet of the liquid receiver, and the second outlet of the liquid receiver is connected to the compressor inlet.

[0008] The first inlet and first outlet of the storage tank are positioned at a lower height than its second inlet and second outlet, and the storage tank is equipped with a liquid level sensor;

[0009] Several evaporators are connected in parallel between the first outlet and the second inlet of the liquid storage tank, and refrigerant pumps are installed on the pipelines between the several evaporators and the liquid storage tank.

[0010] An expansion valve is installed on the pipeline between the condenser and the liquid storage tank, and a pressure sensor is installed on the condenser.

[0011] By setting up a liquid storage tank to store sufficient refrigerant, it is possible to ensure that each evaporator receives a sufficient supply of refrigerant.

[0012] The liquid storage tank is equipped with a minimum liquid level and a maximum liquid level. When the liquid level in the storage tank is lower than the minimum liquid level or higher than the maximum liquid level, the liquid volume in the storage tank is adjusted by controlling the opening of the expansion valve to ensure the reserve of refrigerant and thus ensure that each evaporator can obtain a sufficient supply of refrigerant.

[0013] Preferably, the height of the first inlet and the first outlet of the storage tank is lower than the lowest liquid level.

[0014] Preferably, the second inlet and the second outlet of the storage tank are both located at heights higher than the highest liquid level.

[0015] Furthermore, the storage tank is equipped with a buffer tank, which is connected to the inside of the storage tank via two passages, each equipped with an electronic valve. When the liquid level in the storage tank is higher than the maximum level, some of the refrigerant can be transferred to the buffer tank for storage, relieving pressure inside the storage tank. When the liquid level is lower than the minimum level, the refrigerant stored in the buffer tank can be returned to the storage tank to quickly restore the normal liquid level.

[0016] For ease of manufacturing, the buffer tank is located on the outside of the side wall of the liquid storage tank.

[0017] Preferably, the buffer tank is horizontally arranged around the side wall of the liquid storage tank to make efficient use of space.

[0018] Preferably, the buffer tank is located in the middle between the lowest and highest liquid levels of the storage tank, and both channels are located between the lowest and highest liquid levels of the storage tank, with a preset distance between them, so that the flow of liquid between the storage tank and the buffer tank can be achieved by the hydraulic pressure of the refrigerant itself.

[0019] Preferably, the distance between the upper and lower channels of the buffer tank and the highest and lowest liquid levels is one-third of the distance between the lowest and highest liquid levels of the storage tank.

[0020] Preferably, the volume of the buffer tank is equal to or greater than one-third of the volume between the lowest and highest liquid levels of the storage tank.

[0021] This utility model provides a refrigeration system that can effectively solve the problem of frequent compressor start-stop. By setting up a liquid storage tank to pre-store a certain amount of coolant, it can ensure that each evaporator has a sufficient supply of coolant under various operating conditions, thereby avoiding the problem of frequent compressor start-stop.

[0022] In addition, by setting up a buffer tank, the space pressure of the liquid storage tank is relieved, and the liquid level in the liquid storage tank can be quickly adjusted to restore the normal liquid level, thereby reducing the load on the compressor and condenser. Attached Figure Description

[0023] In the attached diagram:

[0024] Figure 1 This is a schematic diagram of a refrigeration system;

[0025] Figure 2 This is a cross-sectional view of the liquid storage tank;

[0026] Figure 3 This is a schematic diagram of the control method for a refrigeration system.

[0027] The components represented by the various reference numerals in the diagram are:

[0028] 1. Compressor; 2. Condenser; 3. Receiver; 31. First inlet; 32. First outlet; 33. Second inlet; 34. Second outlet; 4. Evaporator; 5. Liquid level sensor; 6. Refrigerant pump; 7. Expansion valve; 8. Pressure sensor; 9. Buffer tank; 91. Passage; 10. Electronic switching valve. Detailed Implementation

[0029] like Figure 1 As shown, this utility model embodiment provides a refrigeration system that can effectively solve the problem of frequent compressor start-stop, including a compressor 1, a condenser 2, a liquid receiver 3 and several evaporators 4 connected by pipelines;

[0030] The outlet of compressor 1 is connected to the inlet of condenser 2, the outlet of condenser 2 is connected to the first inlet 31 of liquid storage tank 3, the first outlet 32 ​​of liquid storage tank 3 is connected to the inlet of several evaporators 4, the outlet of several evaporators 4 is connected to the second inlet 33 of liquid storage tank 3, and the second outlet 34 of liquid storage tank 3 is connected to the inlet of compressor 1.

[0031] The first inlet 31 and the first outlet 32 ​​of the liquid storage tank 3 are positioned at a lower height than its second inlet 33 and the second outlet 34. The liquid storage tank 3 is equipped with a liquid level sensor 5.

[0032] Several evaporators 4 are connected in parallel between the first outlet 32 ​​and the second inlet 33 of the liquid storage tank 3, and refrigerant pumps 6 are respectively installed on the pipelines between the several evaporators 4 and the liquid storage tank 3.

[0033] An expansion valve 7 is installed on the pipeline between the condenser 2 and the liquid storage tank 3, and a pressure sensor 8 is installed on the condenser 2.

[0034] The refrigeration system of this application is equipped with a liquid storage tank 3, which stores a predetermined amount of refrigerant. When each evaporator 4 is working, the liquid storage tank 3 supplies refrigerant, ensuring that each evaporator 4 can obtain a sufficient supply of refrigerant, thereby avoiding the problem of frequent start-stop of the compressor 1.

[0035] The liquid volume in the storage tank 3 can be adjusted by the opening degree of the expansion valve 7.

[0036] The liquid storage tank 3 is equipped with minimum and maximum liquid levels. When the liquid level in the storage tank 3 is below the minimum level, the opening of the expansion valve 7 is increased, ensuring that the inflow of liquid into the storage tank 3 exceeds the outflow, thus increasing the liquid volume in the storage tank 3. When the liquid level is above the maximum level, the expansion valve 7 is closed, allowing only outflow from the storage tank 3, reducing the liquid volume. Simultaneously, the pressure sensor 8 monitors the pressure in the condenser 2 in real time. If the pressure becomes too high, the expansion valve 7 is opened promptly to prevent damage to the condenser 2. By controlling the opening of the expansion valve 7 to regulate the liquid volume in the storage tank 3, the reserve of refrigerant in the storage tank 3 is ensured, thereby guaranteeing that each evaporator 4 receives a sufficient supply of refrigerant under various operating conditions.

[0037] The first inlet 31 and the first outlet 32 ​​of the liquid storage tank 3 are both below the lowest liquid level, while the second inlet 33 and the second outlet 34 of the liquid storage tank 3 are both above the highest liquid level.

[0038] For example Figure 2 As shown, a buffer tank 9 is further provided on the liquid storage tank 3. The buffer tank 9 is connected to the inside of the liquid storage tank 3 through two passages 91 set at the top and bottom. Electronic switching valves 10 are provided on the two passages 91. When the liquid level in the liquid storage tank 3 is higher than the maximum liquid level, the upper passage 91 is opened, allowing some of the refrigerant in the liquid storage tank 3 to flow into the buffer tank 9 for storage. This prevents the liquid level in the liquid storage tank 3 from not dropping below the maximum liquid level or dropping too little when the expansion valve 7 opens due to excessive pressure in the condenser 2, thus relieving the pressure in the space inside the liquid storage tank 3.

[0039] Furthermore, when the liquid level is below the minimum level, if there is refrigerant in the buffer tank 9, the refrigerant stored in the buffer tank 9 can be replenished back into the liquid storage tank 3 to quickly restore the liquid level in the liquid storage tank 3 and reduce the load on the compressor 1 and the condenser 2.

[0040] The buffer tank 9 is located on the outside of the side wall of the liquid storage tank 3 for easy manufacturing and installation.

[0041] The buffer tank 9 can be a ring-shaped box that horizontally surrounds the side wall of the liquid storage tank 3, effectively utilizing the circumferential space of the liquid storage tank 3 and minimizing space occupation.

[0042] The buffer tank 9 is located in the middle between the lowest and highest liquid levels of the storage tank 3. Both channels are located between the lowest and highest liquid levels of the storage tank 3, and are respectively spaced at a preset distance from the lowest and highest liquid levels, so that when the electronic switch valve 10 is opened, the liquid flow between the storage tank 3 and the buffer tank 9 can be achieved by using the hydraulic pressure of the refrigerant itself.

[0043] Furthermore, the distance between the upper and lower channels of the buffer tank 9 and the highest and lowest liquid levels is one-third of the distance between the lowest and highest liquid levels of the storage tank 3, and the volume of the buffer tank 9 is greater than or equal to one-third of the volume between the lowest and highest liquid levels of the storage tank 3.

[0044] When the liquid level in storage tank 3 is higher than the maximum liquid level, opening the electronic switch valve 10 corresponding to the upper channel of buffer tank 9 will lower the liquid level in storage tank 3 to a distance of one-third of the liquid level difference between the minimum and maximum liquid levels. When the liquid level in storage tank 3 is lower than the minimum liquid level, opening the electronic switch valve 10 corresponding to the lower channel of buffer tank 9 will raise the liquid level in storage tank 3 to a level higher than the minimum liquid level, and the distance between the liquid level and the minimum liquid level will be one-third of the liquid level difference between the minimum and maximum liquid levels.

[0045] In both of the above processes, the liquid flow can be achieved by using liquid pressure, and the buffer tank 9 can be emptied while the refrigerant is being added to the storage tank 3.

[0046] See also Figure 3 As shown, the refrigeration system of this application also includes a control unit (not shown in the figure), and the control method of the refrigeration system during use includes the following steps:

[0047] S1. Obtain the liquid level value in storage tank 3 and compare it with the lowest liquid level value. If it is higher than the lowest liquid level value, execute S2; if it is lower than the lowest liquid level value, execute S3.

[0048] During this step, expansion valve 7 remains at its normal opening.

[0049] S2. Compare the obtained liquid level value with the highest liquid level value. If it is higher than the highest liquid level value, execute S4. If it is lower than the highest liquid level value, execute S5.

[0050] S3. Increase the opening of expansion valve 7 by 10%, delay for 5 minutes and then close it. Execute S1.

[0051] During this step, the system will simultaneously shut off the superheat control, and the expansion valve 7 will increase its opening by 10% within 10 minutes.

[0052] S4. Close expansion valve 7, and monitor the pressure value of condenser 2 in real time and compare it with the maximum pressure setting value. If the pressure value of condenser 2 is greater than or equal to the maximum pressure setting value, then execute S5; otherwise, continue to keep expansion valve 7 closed.

[0053] S5. Open expansion valve 7 to activate superheat control;

[0054] In this step, the expansion valve 7 is opened at its normal size.

[0055] In S3, while increasing the opening of the expansion valve 7, the electronic switch valve 10 corresponding to the lower channel of the buffer tank 9 can also be opened. If the buffer tank 9 contains refrigerant, the liquid level in the storage tank 3 can be quickly increased.

[0056] In S4, if the pressure value of condenser 2 is greater than or equal to the maximum pressure setting value, when S5 is executed, the electronic switch valve 10 corresponding to the upper channel of buffer tank 9 can also be opened at the same time, so that the refrigerant in the liquid storage tank 3 flows into the buffer tank 9, quickly reducing the liquid level in the liquid storage tank 3, and preventing the liquid level in the liquid storage tank 3 from remaining high when the expansion valve 7 is opened.

[0057] The maximum liquid level value of the storage tank 3, the minimum liquid level value, the maximum pressure setting value of the condenser 2, the opening adjustment of the expansion valve 7, the preset liquid level height in the storage tank 3, and the continuous opening delay time of the expansion valve 7 described above should all be set separately according to the specific system.

Claims

1. A refrigeration system that can effectively solve the problem of frequent compressor start-stop, characterized in that, It includes a compressor (1), a condenser (2), a liquid receiver (3), and several evaporators (4) connected by pipelines; The outlet of the compressor (1) is connected to the inlet of the condenser (2), the outlet of the condenser (2) is connected to the first inlet (31) of the liquid storage tank (3), the first outlet (32) of the liquid storage tank (3) is connected to the inlet of a plurality of evaporators (4), the outlet of the plurality of evaporators (4) is connected to the second inlet (33) of the liquid storage tank (3), and the second outlet (34) of the liquid storage tank (3) is connected to the inlet of the compressor (1). The first inlet (31) and the first outlet (32) of the liquid storage tank (3) are positioned at a height lower than its second inlet (33) and the second outlet (34), and the liquid storage tank (3) is equipped with a liquid level sensor (5); The plurality of evaporators (4) are connected in parallel between the first outlet (32) and the second inlet (33) of the liquid storage tank (3), and a refrigerant pump (6) is provided on the pipeline between the plurality of evaporators (4) and the liquid storage tank (3); An expansion valve (7) is provided on the pipeline between the condenser (2) and the liquid storage tank (3), and a pressure sensor (8) is provided on the condenser (2).

2. A refrigeration system as described in claim 1 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The storage tank (3) is equipped with a minimum liquid level and a maximum liquid level.

3. A refrigeration system as described in claim 2 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The first inlet (31) and the first outlet (32) of the liquid storage tank (3) are both located at heights below the lowest liquid level.

4. A refrigeration system as described in claim 3 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The second inlet (33) and the second outlet (34) of the liquid storage tank (3) are both located at heights higher than the highest liquid level.

5. A refrigeration system as described in claim 2 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The liquid storage tank (3) is equipped with a buffer tank (9), which is connected to the inside of the liquid storage tank (3) through two passages (91) set at the top and bottom. The two passages (91) are equipped with electronic switch valves (10).

6. A refrigeration system as described in claim 5 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The buffer tank (9) is located on the outside of the side wall of the liquid storage tank (3).

7. A refrigeration system as described in claim 6 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The buffer tank (9) is horizontally arranged around the side wall of the liquid storage tank (3).

8. A refrigeration system as described in claim 7 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The buffer tank (9) is located in the middle between the lowest and highest liquid levels of the storage tank (3). Both channels are located between the lowest and highest liquid levels of the storage tank (3) and are respectively at a preset distance from the lowest and highest liquid levels.

9. A refrigeration system as described in claim 8 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The distance between the upper and lower channels of the buffer tank (9) and the highest and lowest liquid levels is one-third of the distance between the lowest and highest liquid levels of the storage tank (3).

10. A refrigeration system as described in claim 9 that can effectively solve the problem of frequent compressor start-stop, characterized in that, The volume of the buffer tank (9) is greater than or equal to one-third of the volume between the lowest and highest liquid levels of the storage tank (3).

Images