A cryogenic refrigeration device

Abstract

This utility model discloses a low-temperature refrigeration device, comprising a circuit consisting of a compressor, a first condenser, a liquid receiver, a first expansion valve, an evaporator, and a gas-liquid separator; it also includes a second condenser, a three-way valve, a one-way valve, a solenoid valve, and a second expansion valve; the first port of the three-way valve is connected to one end of the second condenser, the second port of the three-way valve is bypassed to the evaporator and the gas-liquid separator, and the third port of the three-way valve is connected to the compressor and the first condenser; the other end of the second condenser is bypassed to the first condenser and the liquid receiver via a one-way valve pipeline; the inlet end of the second expansion valve is bypassed to the first condenser and the liquid receiver, and the outlet end of the second expansion valve is bypassed to the second condenser and the one-way valve; the solenoid valve is connected between the liquid receiver and the first expansion valve. This utility model enables the air conditioning compressor to start normally at low temperatures.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration and air conditioning, specifically a low-temperature refrigeration device. Background Technology

[0002] Some refrigeration and air conditioning units need to operate in winter. In low outdoor temperatures, the compressor often struggles to start because refrigerant accumulates in the outdoor unit's condenser, leaving the indoor evaporator without sufficient refrigerant, making it increasingly difficult to start the refrigeration system. Common methods to achieve low-temperature cooling include using variable-speed condenser fans and receiver-heating systems. However, these methods are often unreliable, failing to reliably start at even lower temperatures and are costly. While variable-speed condenser fans can ensure normal operation of the refrigeration system in low-temperature environments, they still cannot overcome the difficulty of starting the compressor at low temperatures. Receiver-heating systems require a long preheating time, cannot be started immediately, and require a larger electric heating capacity at even lower ambient temperatures; otherwise, they still cannot start. Furthermore, the fire safety of the electric heating and insulation materials cannot be ignored. Utility Model Content

[0003] This invention provides a low-temperature refrigeration device to solve the problem of compressor start-up difficulties in existing refrigeration and air conditioning devices at low temperatures.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A low-temperature refrigeration device includes a compressor (1), a first condenser (2), a liquid receiver (8), a first expansion valve (10), an evaporator (11), and a gas-liquid separator (12). The refrigerant outlet of the compressor (1) is connected to one end of the first condenser (2) through a pipeline, and the other end of the first condenser (2) is connected to the liquid receiver (8) through a pipeline. The inlet end of the first expansion valve (10) is connected to the liquid receiver (8) through a pipeline, and the outlet end of the first expansion valve (10) is connected to one end of the evaporator (11) through a pipeline. The other end of the evaporator (11) is connected to the inlet end of the gas-liquid separator (12) through a pipeline. The outlet end of the gas-liquid separator (12) is connected to the refrigerant return port of the compressor (1) through a pipeline. The device also includes a second condenser (6), a three-way valve (7), a one-way valve (4), a solenoid valve (9), and a second expansion valve (5). The first valve port (7a) of the three-way valve (7) is connected to one end of the second condenser (6) through a pipeline, the second valve port (7b) of the three-way valve (7) is connected to the pipeline between the evaporator (11) and the gas-liquid separator (12) through a pipeline bypass, and the third valve port (7c) of the three-way valve (7) is connected to the pipeline between the compressor (1) and the first condenser (2) through a pipeline bypass; The other end of the second condenser (6) is connected to the inlet end of the check valve (4), and the outlet end of the check valve (4) is connected to the pipeline between the first condenser (2) and the liquid receiver (8) through a pipeline bypass. The inlet end of the second expansion valve (5) is connected to the pipeline between the first condenser (2) and the liquid receiver (8) via a bypass pipeline, and the outlet end of the second expansion valve (5) is connected to the pipeline between the second condenser (6) and the check valve (4) via a bypass pipeline. The solenoid valve (9) is connected to the pipeline between the liquid reservoir (8) and the first expansion valve (10).

[0005] Furthermore, the first condenser (2) and the second condenser (6) share a condenser fan (3).

[0006] Furthermore, the reservoir (8) is a dual-flow reservoir.

[0007] Furthermore, when the solenoid valve (9) is open and the three-way valve (7) is switched to connect the third valve port (7c) and the first valve port (7a), the first condenser (2) and the second condenser (6) are connected in parallel to cooperate with the evaporator, thereby forming the first refrigeration cycle.

[0008] Furthermore, when the solenoid valve (9) is closed and the three-way valve (7) is switched to connect the second valve port (7b) and the first valve port (7a), the first condenser (2) and the second condenser (6) are connected in series to realize the second refrigeration cycle.

[0009] This invention divides the outdoor condenser of the refrigeration system into two groups. One group of condensers always maintains the role of a condenser, while the other group of condensers can form a second refrigeration cycle by switching refrigeration components such as a three-way valve, a second expansion valve, and a one-way valve. At the same time, the solenoid valve of the original refrigeration system on the indoor side is in the closed state, so the indoor evaporator does not participate in the refrigeration cycle at this time.

[0010] When the refrigeration system switches to normal operation, both sets of condensers operate in parallel as condensers. This design makes full use of the condenser's heat exchange area, resulting in a very compact refrigeration system without the need for additional heat dissipation area. Because the refrigeration system only requires a small heat exchange area in low-temperature environments, using one set of condensers as an evaporator has no impact on the refrigeration system.

[0011] In addition, to ensure the normal operation of the entire refrigeration system, this invention is equipped with a dual-flow liquid receiver, which can store excess liquid refrigerant and balance the refrigeration system in both the first and second refrigeration cycles.

[0012] The refrigeration solenoid valve is an essential component of all low-temperature refrigeration systems. In the refrigeration cycle designed in this invention, when the second refrigeration cycle starts, the solenoid valve is in the closed state. At this time, there is no refrigerant supply to the indoor evaporator, so there is sufficient refrigerant to ensure the operation of the second refrigeration cycle.

[0013] Once the refrigeration system starts normally and establishes sufficient high and low pressures, the three-way valve can be switched to the first refrigeration cycle, and the solenoid valve can be opened to supply refrigerant to the indoor evaporator. At this time, the outdoor condenser fan can be adjusted to maintain the high pressure of the refrigeration system within a reasonable range, ensuring the system continues to operate normally.

[0014] This invention enables the compressor in a refrigeration system to start normally at relatively low ambient temperatures, and its design is simple and easy to implement, offering the following advantages: 1. The refrigeration system has no extra heat dissipation area, its structure is relatively simple, and the main refrigeration components are easy to purchase.

[0015] 2. No heating is required for the outdoor liquid receiver, ensuring that the refrigeration system can start quickly, making it more energy-efficient and safer.

[0016] 3. High reliability, with no substantial technical obstacles. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of this utility model. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] like Figure 1 As shown, this embodiment discloses a low-temperature refrigeration device, including a compressor 1, a first condenser 2, a one-way valve 4, a second expansion valve 5, a second condenser 6, a three-way valve 7, a liquid receiver 8, a solenoid valve 9, a first expansion valve 10, an evaporator 11, and a gas-liquid separator 12. The evaporator 11 is located on the indoor side and is equipped with an evaporation fan. The first condenser 2 and the second condenser 6 are both located on the outdoor side, and the first condenser 2 and the second condenser 6 share the same condenser fan 3.

[0020] The refrigerant outlet of compressor 1 is connected to one end of the first condenser 2 via a pipeline. The other end of the first condenser 2 is connected to one interface of the liquid receiver 8 via a pipeline. The other interface of the liquid receiver 8 is connected to the inlet end of the first expansion valve 10 via a pipeline. The outlet end of the first expansion valve 10 is connected to one end of the evaporator 11 via a pipeline. The other end of the evaporator 11 is connected to the inlet end of the gas-liquid separator 12 via a pipeline. The outlet end of the gas-liquid separator 12 is connected to the refrigerant return port of compressor 1 via a pipeline.

[0021] The first valve port 7a of the three-way valve 7 is connected to one end of the second condenser 6 through a pipeline. The second valve port 7b of the three-way valve 7 is connected to the pipeline between the other end of the evaporator 11 and the inlet end of the gas-liquid separator 12 through a bypass pipeline. The third valve port 7c of the three-way valve 7 is connected to the pipeline between the refrigerant outlet of the compressor 1 and one end of the first condenser 2 through a bypass pipeline.

[0022] The other end of the second condenser 6 is connected to the inlet end of the one-way valve 4, and the outlet end of the one-way valve 4 is connected to the pipeline between the other end of the first condenser 2 and one interface of the liquid receiver 8 through a pipeline bypass.

[0023] The inlet of the second expansion valve 5 is connected via a bypass pipeline to the other end of the first condenser 2 and one interface of the liquid receiver 8. The outlet of the second expansion valve 5 is connected via a bypass pipeline to the other end of the second condenser 6 and the inlet of the check valve 4.

[0024] The solenoid valve 9 is connected to the pipeline between another interface of the liquid reservoir 8 and the inlet of the first expansion valve 10.

[0025] In this embodiment, the liquid reservoir 8 is a dual-flow liquid reservoir, that is, the liquid reservoir 8 has two interfaces 8a and 8b, each of which can be used as an input port or an output port.

[0026] When the refrigeration system needs to be started in a low-temperature environment, the refrigeration system enters the second refrigeration cycle mode. At this time, the solenoid valve 9 is closed, and the three-way valve 7 switches to connect the first valve port 7a and the second valve port 7b, while the third valve port 7c is closed. The exhaust gas from the compressor 1 flows through the first condenser 2 and condenses into liquid refrigerant. Then, the liquid refrigerant flows through the second expansion valve 5 and enters the second condenser 6. As a result, the solenoid valve 9 closes, and the refrigerant cannot enter the evaporator 11 on the indoor side. At this time, the second condenser 6 is used as an evaporator. The liquid refrigerant is depressurized and evaporates into gaseous refrigerant in the second condenser 6, and then flows through the first valve port 7a and the second valve port 7b of the three-way valve 7, enters the gas-liquid separator 12, and then enters the suction port of the compressor 1. The refrigeration cycle continues in this way. In this second refrigeration cycle, if there is excess liquid refrigerant, it will enter the dual-flow receiver 8 through its first port 8a. If the second refrigeration cycle requires more liquid refrigerant, the liquid refrigerant stored in the dual-flow receiver 8 will return to the second refrigeration cycle through its own first port 8a to replenish the required amount. Since the solenoid valve 9 is in the closed state, refrigerant cannot enter the indoor evaporator 11. Therefore, the function of the dual-flow receiver 8 at this time is to maintain a stable refrigerant circulation volume in the second refrigeration cycle.

[0027] Once the second refrigeration cycle is operating stably, it can switch to the first refrigeration cycle mode according to the user's cooling needs. At this time, the three-way valve 7 switches to the first valve port 7a and the third valve port 7c being connected, while the second valve port 7b is closed; in addition, the solenoid valve 9 is connected; at this time, the second condenser 6 switches to condenser mode and forms a parallel condenser relationship with the first condenser 2. At this time, the exhaust gas from the compressor 1 will be divided into two paths: one path flows through the first condenser 2 and condenses into liquid refrigerant therein; the other path flows through the 7c and 7a ports of the three-way valve 7 and enters the second condenser 6 to dissipate heat and condense into liquid refrigerant, then splits into two paths, flowing through the one-way valve 4 and the second expansion valve 5 respectively (at this time, the second expansion valve 5 is in a counter-current state and forms a parallel flow relationship with the one-way valve 4, because the second expansion valve 5 enters...). The outlet liquid refrigerant pressure is the same, and the expansion valve has extremely high flow resistance and is in a counter-current state. Therefore, the flow rate of refrigerant flowing through expansion valve 5 is very small and can be ignored. Since the first condenser 2 and the second condenser 6 are in parallel condenser state, the second condenser 6 mixes with the liquid refrigerant from the first condenser 2. At this time, the liquid refrigerant from the condenser enters the dual-flow liquid receiver 8 from the first port 8a. The liquid refrigerant required for the first refrigeration cycle flows out from the second port 8b of the dual-flow liquid receiver 8 and flows through the solenoid valve 9. It then enters the first expansion valve 10, is depressurized, and enters the evaporator 11, where it absorbs heat and evaporates into gaseous refrigerant. After passing through the gas-liquid separator 12, it enters the suction port of the compressor 1 and continues to circulate.

[0028] During the first refrigeration cycle, the condenser fan 3 can automatically adjust according to the high pressure of the refrigeration system to ensure that the high and low pressures of the refrigeration system are within a reasonable range.

[0029] In addition, if the user's cooling capacity is met while the first refrigeration cycle is running, but the compressor does not want to stop, the second refrigeration cycle can be switched to continue running.

[0030] As described above, this utility model, through a very reasonable refrigeration system design, enables the refrigeration system to start reliably in low-temperature environments and then smoothly switch to the normal refrigeration cycle. It has a simple and reliable structure, no complex redundant parts, and has great practical value.

[0031] The preferred embodiments of this utility model have been described in detail above with reference to the accompanying drawings. These embodiments are merely descriptions of preferred embodiments and are not intended to limit the concept and scope of this utility model. The various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. Such combinations, as long as they do not violate the spirit of this utility model, should also be considered as part of this disclosure. To avoid unnecessary repetition, this utility model will not further describe all possible combinations.

[0032] This utility model is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this utility model and without departing from the design idea of ​​this utility model, all modifications and improvements made by those skilled in the art to the technical solution of this utility model should fall within the protection scope of this utility model. The technical content for which protection is sought in this utility model has been fully recorded in the claims.

Claims

1. A cryogenic refrigeration device, comprising a compressor (1), a first condenser (2), a liquid receiver (8), a first expansion valve (10), an evaporator (11), and a gas-liquid separator (12), wherein the refrigerant outlet of the compressor (1) is connected to one end of the first condenser (2) via a pipeline, the other end of the first condenser (2) is connected to the liquid receiver (8) via a pipeline, the inlet end of the first expansion valve (10) is connected to the liquid receiver (8) via a pipeline, the outlet end of the first expansion valve (10) is connected to one end of the evaporator (11) via a pipeline, the other end of the evaporator (11) is connected to the inlet end of the gas-liquid separator (12) via a pipeline, and the outlet end of the gas-liquid separator (12) is connected to the refrigerant return port of the compressor (1) via a pipeline, characterized in that, It also includes a second condenser (6), a three-way valve (7), a one-way valve (4), a solenoid valve (9), and a second expansion valve (5); The first valve port (7a) of the three-way valve (7) is connected to one end of the second condenser (6) through a pipeline, the second valve port (7b) of the three-way valve (7) is connected to the pipeline between the evaporator (11) and the gas-liquid separator (12) through a pipeline bypass, and the third valve port (7c) of the three-way valve (7) is connected to the pipeline between the compressor (1) and the first condenser (2) through a pipeline bypass; The other end of the second condenser (6) is connected to the inlet end of the check valve (4), and the outlet end of the check valve (4) is connected to the pipeline between the first condenser (2) and the liquid receiver (8) through a pipeline bypass. The inlet end of the second expansion valve (5) is connected to the pipeline between the first condenser (2) and the liquid receiver (8) via a bypass pipeline, and the outlet end of the second expansion valve (5) is connected to the pipeline between the second condenser (6) and the check valve (4) via a bypass pipeline. The solenoid valve (9) is connected to the pipeline between the liquid reservoir (8) and the first expansion valve (10).

2. The cryogenic refrigeration device according to claim 1, characterized in that, The first condenser (2) and the second condenser (6) share a condenser fan (3).

3. The cryogenic refrigeration device according to claim 1, characterized in that, The liquid reservoir (8) is a dual-flow liquid reservoir.

4. A cryogenic refrigeration device according to any one of claims 1-3, characterized in that, When the solenoid valve (9) is open and the three-way valve (7) is switched to connect the third valve port (7c) and the first valve port (7a), the first condenser (2) and the second condenser (6) are connected in parallel to cooperate with the evaporator, thereby forming the first refrigeration cycle.

5. A cryogenic refrigeration device according to any one of claims 1-3, characterized in that, When the solenoid valve (9) is closed and the three-way valve (7) is switched to connect the second valve port (7b) and the first valve port (7a), the first condenser (2) and the second condenser (6) are connected in series to realize the second refrigeration cycle.

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