Refrigerating system for low-temperature scroll compressor stable starting and low-load operation
By using a balancing bypass expansion valve and a check valve in a low-temperature refrigeration system, the high and low-pressure pressures are quickly balanced, and by balancing the bypass expansion valve and low-pressure sensor combined, the low-load non-negative pressure operation state is maintained, which solves the problems of large load torque during starting and cannot be maintained during low-load operation in the prior art, and the effect of smooth start of the compressor and long-term operation of low load is achieved.
Patent Information
- Application Number
- CN202510219095.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2025-06-06
AI Technical Summary
The existing low-temperature refrigeration system has a large instantaneous load torque when starting under high pressure ratio in summer, and cannot maintain long-term operation during low-load operation, which cannot meet certain refrigeration process requirements.
It uses a combination of a balancing by-circuit expansion valve and a check valve to quickly balance the high and low pressure pressure of the refrigeration system, reduce the starting current, and maintain a low-load non-negative pressure operating state through a combination of a balancing by-circuit expansion valve and a low-pressure sensor.
It realizes smooth and reliable start of the compressor, reduces the starting current and impact on the power grid, meets the demand for low loads to run for a long time, and improves the operating reliability of the refrigeration system.
Smart Images
Figure CN120101334A_ABST
Abstract
Description
Technical Field
[0001] The invention discloses a low-temperature scroll compressor smooth start and low-load operation refrigeration system, which relates to the technical field of low-temperature refrigeration, and in particular to a low-temperature scroll compressor smooth start and low-load operation refrigeration system. Background Art
[0002] At present, low-temperature refrigeration technology has a wide range of application scenarios. The refrigeration process is that after the high-temperature and high-pressure refrigerant is condensed by the condenser, the high-pressure refrigerant liquid is throttled and depressurized, and the refrigerant enters the evaporator to absorb heat to complete the refrigeration and cooling process requirements. The suction pressure of the compressor is controlled by a low-pressure sensor to achieve the low-temperature refrigeration process requirements for the use scenario. At present, low-temperature refrigeration is widely used in food, medicine, chemical industry, military industry, aerospace, semiconductors and scientific research.
[0003] When the existing low-temperature refrigeration system is started up in the summer when facing a high pressure ratio, the starting torque of the compressor is closely related to the suction and exhaust pressure. The starting torque increases with the increase of the compression ratio. The higher the exhaust pressure, the greater the torque the motor needs to provide. When starting after a short shutdown, there is a torque required to overcome the pressure difference, especially for a single-phase refrigeration system, which greatly increases the instantaneous load torque at startup. This refrigeration system can quickly balance the high and low pressures by using a balanced bypass expansion valve 2 and a one-way valve 4 in combination, reduce the starting current, improve the starting performance of the low-temperature scroll compressor, and improve the operating reliability of the refrigeration system.
[0004] In the existing low-temperature refrigeration system, when the load span is large and the system is running at low load, the compressor cannot maintain low load operation for a long time and does not meet certain refrigeration process requirements. This refrigeration system uses a balanced bypass expansion valve 2 and a low-pressure sensor 15 in combination to meet the purpose of maintaining low load non-negative pressure operation with a large load span. The low-pressure sensor in the refrigeration system sets a low-pressure shutdown value. When the load becomes low, a control logic is set to ensure that the compressor maintains low load non-negative pressure operation. When the difference between the low-pressure operating pressure and the low-pressure shutdown value is less than 0.3 bar, the balanced bypass expansion valve is opened and operated. The balanced bypass expansion valve is an electronic expansion valve that can be completely closed. The balanced bypass expansion valve can control the low-pressure operating pressure by controlling its opening steps through a program, thereby achieving the purpose of maintaining stable operation at low load and meeting special refrigeration process requirements.
[0005] In view of the problems existing in the above-mentioned prior art, it is very necessary to study and design a new type of low-temperature scroll compressor smooth start and low-load operation refrigeration system to overcome the problems existing in the prior art. Summary of the invention
[0006] In view of the problems existing in the above-mentioned prior art, a refrigeration system with a low-temperature scroll compressor having smooth start and low-load operation is provided.
[0007] The technical means adopted by the present invention are as follows:
[0008] A low-temperature scroll compressor smooth start and low-load operation refrigeration system is a closed-loop refrigeration system consisting of a compressor, a high-pressure switch, a check valve, an oil separator, a condenser, a liquid storage device, a drying filter, a liquid pipe solenoid valve, a sight glass, an expansion valve, an evaporator, a gas-liquid separator, an air intake filter, a low-pressure sensor and then a compressor connected in sequence;
[0009] Furthermore, the exhaust pipe and the suction pipe of the compressor are respectively connected to the inlet end A and the outlet end B of the balanced bypass expansion valve to form a gas refrigerant circuit.
[0010] Furthermore, the compressor has a scroll-type internal low-pressure chamber structure.
[0011] Furthermore, the inlet end A of the balanced bypass expansion valve is the high-pressure side, and the outlet end B is the low-pressure side.
[0012] Further, the inlet port A of the balanced bypass expansion valve is arranged on the pipeline between the high pressure side of the compressor and the one-way valve;
[0013] Furthermore, the outlet port B of the balanced bypass expansion valve is arranged on the pipeline between the evaporator and the gas-liquid separator.
[0014] Furthermore, the combined use of the balanced bypass expansion valve and the one-way valve can meet the requirement of quickly balancing the high and low pressures to achieve rapid startup when the refrigeration system faces a large pressure ratio when the ambient temperature is high, ensuring the smooth and reliable operation of the compressor.
[0015] Furthermore, the combined use of the balanced bypass expansion valve and the one-way valve can meet the needs of quickly balancing the pressure of the refrigeration system when the ambient temperature is high, thereby reducing the starting current of the compressor and reducing the impact on the power grid.
[0016] Furthermore, the balanced bypass expansion valve and the low-pressure sensor need to be used in combination. The low-pressure shutdown value and the startup pressure starting value are set for the low-temperature refrigeration system low-pressure sensor. For refrigeration systems with a large load span, when the load becomes low, in order to ensure that the compressor maintains low-load non-negative pressure operation, a control logic is set. When the difference between the low-pressure operating pressure and the low-pressure shutdown value is less than 0.3 bar, the balanced bypass expansion valve opens and operates. The balanced bypass expansion valve is an electronic expansion valve that can be completely closed. This balanced bypass expansion valve can control the low-pressure operating pressure by controlling its opening steps through a program, thereby achieving the purpose of maintaining the refrigeration system in low-load operation.
[0017] Furthermore, the compressor equalized pressure starting can reduce the starting current and reduce the impact on the power grid.
[0018] Furthermore, HFC refrigerants include: R404A, R448A, R449A, and R507A.
[0019] Furthermore, the low-temperature refrigeration system can be used in low-temperature cold storage, low-temperature testing equipment and low-temperature related fields.
[0020] Compared with the prior art, the present invention has the following advantages:
[0021] 1. The present invention provides a low-temperature scroll compressor stable start and low-load operation refrigeration system, which uses a balanced bypass expansion valve and a one-way valve in combination; it can quickly balance the high and low pressures of the refrigeration system to avoid the compressor starting and running under pressure;
[0022] 2. The present invention provides a low-temperature scroll compressor smooth start and low-load operation refrigeration system, in which a balanced bypass expansion valve and a low-pressure sensor are used in combination; the purpose of maintaining a large refrigeration load span and low-load non-negative pressure operation can be achieved, and the refrigeration process requirements of the refrigeration system can be met.
[0023] 3. The present invention provides a low-temperature scroll compressor smooth start and low-load operation refrigeration system. The function of the balanced bypass expansion valve is to make the high-pressure gaseous refrigerant on the exhaust side flow to the low-pressure suction side. The principle is similar to the function of a one-way valve. When the compressor needs to start, the balanced bypass expansion valve opens. After the compressor starts, the balanced bypass expansion valve closes. When the unit needs to maintain low-load non-negative pressure operation, the balanced bypass expansion valve opens again. Through the above-mentioned control logic, the low-temperature refrigeration process requirements are achieved. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0025] Figure 1 Schematic diagram of the system of the present invention.
[0026] In the figure: 1, compressor 2, balanced bypass expansion valve 3, high-pressure switch 4, non-return valve 5, oil separator 6, condenser 7, liquid reservoir 8, dry filter 9, liquid pipe solenoid valve 10, sight glass 11, expansion valve 12, evaporator 13, gas-liquid separator 14, suction filter 15, low-pressure sensor. DETAILED DESCRIPTION
[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.
[0030] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts and steps described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.
[0031] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.
[0032] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0033] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.
[0034] like Figure 1 As shown, the present invention provides a low-temperature scroll compressor smooth start and low-load operation refrigeration system;
[0035] Compressor 1 is a low-pressure scroll compressor, that is, the compressor motor is located in the low-pressure chamber of the compressor.
[0036] like Figure 1 As shown, the compressor 1, the balanced bypass expansion valve 2, the high pressure switch 3, the check valve 4, the oil separator 5, the condenser 6, the liquid storage 7, the drying filter 8, the liquid pipe solenoid valve 9, the sight glass 10, the expansion valve 11, the evaporator 12, the gas-liquid separator 13, the suction filter 14, and the low pressure sensor 15 are connected in sequence to form a refrigeration system;
[0037] In the refrigeration system, a balanced bypass expansion valve 2 and a one-way valve 4 are used in combination, wherein the inlet A of the balanced bypass expansion valve 2 is connected to the exhaust pipe at the high-pressure end of the compressor 1, and the outlet B of the balanced bypass expansion valve 2 is connected to the suction pipe at the low-pressure end of the compressor 1, and the inlet A of the balanced bypass expansion valve 2 is arranged between the compressor 1 and the exhaust one-way valve 4. This system can quickly balance the high and low pressures of the refrigeration system before restarting after a short shutdown in a high-temperature environment in summer, and at the same time can reduce the starting current and reduce the impact on the power grid, creating conditions for smooth operation at startup; especially for the vortex single-phase refrigeration system, the application of this system can make its refrigeration system run more smoothly.
[0038] The combined use of the balanced bypass expansion valve 2 and the low-pressure sensor 15 in the refrigeration system can meet the requirement of maintaining low-load non-negative pressure operation when the load span of the refrigeration system is large; the low-pressure sensor in the refrigeration system sets a low-pressure shutdown value and sets a control logic. When the load becomes low, when the difference between the low-pressure operating pressure and the low-pressure shutdown value is less than 0.3 bar, the balanced bypass expansion valve opens and operates. The balanced bypass expansion valve is an electronic expansion valve that can be completely closed. This balanced bypass expansion valve can control the low-pressure operating pressure by controlling its opening steps through a program, thereby achieving the purpose of maintaining low-load non-negative pressure operation. The application of this system can enable the refrigeration system to meet certain refrigeration process requirements.
[0039] The refrigerant is HFC refrigerant such as R404A, R448A, R449A, R507A, etc.
[0040] In addition to being used in low-temperature cold storage, the refrigeration system can also be used in low-temperature environmental test chambers and other low-temperature application fields.
[0041] In use: Low-temperature scroll compressor refrigeration system, the refrigeration process is that after the high-temperature and high-pressure refrigerant is condensed by the condenser, the high-pressure refrigerant liquid is throttled and depressurized, and the refrigerant enters the evaporator to absorb heat to complete the refrigeration and cooling process requirements. When the temperature rises in the use scenario and needs to be turned on again for cooling, the high and low pressures of the refrigeration system can be quickly balanced by combining the balanced bypass expansion valve 2 and the exhaust check valve 4 in the system, reducing the starting current, thereby ensuring the smooth operation of the compressor 1 when it is turned on.
[0042] In use: Low-temperature scroll compressor refrigeration system, when the use scenario is in a state of large refrigeration load span, effective adjustment can be performed through the combined use of the balanced bypass expansion valve 2 and the low-pressure sensor 15 in the system, thereby ensuring that the compressor 1 maintains a low-load non-negative pressure state and operates reliably.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A low-temperature scroll compressor smooth start and low-load operation refrigeration system, characterized in that: The low-temperature scroll compressor smooth start and low-load operation refrigeration system is a closed-loop refrigeration system consisting of a compressor (1), a high-pressure switch (3), a one-way valve (4), an oil separator (5), a condenser (6), a liquid storage device (7), a drying filter (8), a liquid pipe solenoid valve (9), a sight glass (10), an expansion valve (11), an evaporator (12), a gas-liquid separator (13), an air intake filter (14), a low-pressure sensor (15) and then the compressor (1) connected in sequence; The exhaust pipe and the intake pipe of the compressor (1) are respectively connected to the inlet end A and the outlet end B of the balanced bypass expansion valve (2), forming a gas refrigerant circuit.
2. The low-temperature scroll compressor smooth start and low-load operation refrigeration system according to claim 1, characterized in that: The compressor (1) is a scroll-type internal low-pressure chamber structure.
3. The low-temperature scroll compressor smooth start and low-load operation refrigeration system according to claim 1, characterized in that: The inlet end A of the balanced bypass expansion valve (2) is the high-pressure side, and the outlet end B is the low-pressure side.
4. The low-temperature scroll compressor smooth start and low-load operation refrigeration system according to claim 1, characterized in that: The inlet end A of the balanced bypass expansion valve (2) is arranged on the pipeline between the high-pressure side of the compressor (1) and the one-way valve (4); The outlet end B of the balanced bypass expansion valve (2) is arranged on the pipeline between the evaporator (12) and the gas-liquid separator (13).
5. The low-temperature scroll compressor smooth start and low-load operation refrigeration system according to claim 4, characterized in that: The combined use of the balanced bypass expansion valve (2) and the one-way valve (4) can meet the requirement of quickly balancing the high and low pressures to achieve rapid startup when the refrigeration system faces a large pressure ratio when the ambient temperature is high, thereby ensuring the smooth and reliable operation of the compressor.
6. The low-temperature scroll compressor smooth start and low-load operation refrigeration system according to claim 4, characterized in that: The combined use of the balanced bypass expansion valve (2) and the one-way valve (4) can meet the requirement of quickly balancing the pressure of the refrigeration system when the ambient temperature is high, thereby reducing the starting current of the compressor and reducing the impact on the power grid.
7. The low-temperature scroll compressor smooth start and low-load operation refrigeration system according to claim 1, characterized in that: The balanced bypass expansion valve (2) and the low-pressure sensor (15) need to be used in combination. A low-pressure shutdown value and a startup pressure starting value are set for the low-temperature refrigeration system low-pressure sensor. For a refrigeration system with a large load span, when the load becomes low, in order to ensure that the compressor maintains low-load non-negative pressure operation, a control logic is set. When the difference between the low-pressure operating pressure and the low-pressure shutdown value is less than 0.3 bar, the balanced bypass expansion valve is opened and operated. The balanced bypass expansion valve is an electronic expansion valve that can be completely closed. The balanced bypass expansion valve can control the low-pressure operating pressure by controlling its opening steps through a program, thereby achieving the purpose of maintaining low-load operation of the refrigeration system.