Refrigeration cycle system and air conditioning system

Abstract

The application discloses a refrigeration cycle system and an air conditioning system. The refrigeration cycle system comprises a compressor, a condenser, an evaporator and at least one throttling device connected between the condenser and the evaporator. The throttling device comprises: a first throttling flow path connected between the condenser and the evaporator and comprising a first throttling element; and a second throttling flow path connected between the condenser and the evaporator and having an inlet and an outlet connected in parallel with the inlet and the outlet of the first throttling flow path respectively. The second throttling flow path comprises a differential pressure regulating valve and a second throttling element connected in series. When the pressure difference between the inlet and the outlet of the differential pressure regulating valve is less than a first threshold value, the fluid passage of the differential pressure regulating valve is open. When the pressure difference between the inlet and the outlet of the differential pressure regulating valve is greater than the first threshold value, the fluid passage of the differential pressure regulating valve is closed. The refrigeration cycle system of the application is suitable for occasions such as mine-used explosion-proof refrigeration devices and can automatically adjust the throttling capacity in a large range and is safe and reliable.

Description

Technical Field

[0001] This invention relates to the field of refrigeration cycle technology, and particularly to a refrigeration cycle system and an air conditioning system. Background Technology

[0002] The refrigeration cycle includes compression, condensation, expansion, and evaporation. Correspondingly, the compressor, condenser, throttling element, and evaporator are the four main components of the refrigeration cycle system in air conditioning and other refrigeration equipment. Commonly used throttling elements include electric electronic expansion valves, orifice plates, thermostatic expansion valves, dual electric electronic expansion valves, and electronic or thermostatic expansion valves with capillary tubes. For electronic throttling elements, temperature and pressure sensors are typically installed on the compressor's discharge line to detect exhaust superheat and convert it into an electrical signal. This signal is then applied to a stepper motor to directly drive the valve piston, controlling the valve opening and regulating the refrigerant flow. However, for refrigeration equipment used in specific applications, such as explosion-proof refrigeration systems in coal mines, where the air contains a mixture of methane, carbon dioxide, and nitrogen, exposure to electrical signals can easily lead to explosions or other accidents. Therefore, commonly used throttling elements requiring electrical signals, such as electronic expansion valves, are unsuitable. Furthermore, mine explosion-proof refrigeration units employ a multi-system combined operation. During operation, the different systems exhibit significant differences in water temperature and load, necessitating a wide range of throttling capabilities during actual unit operation. While traditional throttling devices such as thermostatic expansion valves meet safety requirements, their adjustment range is limited. Using a thermostatic expansion valve with a small throttling capacity fails to meet the unit's throttling requirements, impacting unit performance. Conversely, using a thermostatic expansion valve with a large throttling capacity results in excessive throttling under normal operating conditions, potentially leading to liquid carryover within the unit. Summary of the Invention

[0003] The purpose of this invention is to provide a safe and reliable refrigeration cycle system that can automatically adjust its throttling capacity over a wide range of applications, such as explosion-proof refrigeration devices for mining.

[0004] The first aspect of this invention discloses a refrigeration cycle system, including a compressor, a condenser, an evaporator, and at least one throttling device connected between the condenser and the evaporator, the throttling device comprising:

[0005] The first throttling flow path is connected between the condenser and the evaporator, and includes a first throttling element;

[0006] The second throttling flow path is connected between the condenser and the evaporator, and its inlet and outlet are connected in parallel with the inlet and outlet of the first throttling flow path, respectively. The second throttling flow path includes a differential pressure regulating valve and a second throttling element connected in series. When the pressure difference between the inlet and outlet of the differential pressure regulating valve is less than a first threshold, the fluid passage of the differential pressure regulating valve is opened. When the pressure difference between the inlet and outlet of the differential pressure regulating valve is greater than the first threshold, the fluid passage of the differential pressure regulating valve is closed.

[0007] In some embodiments, the second throttling element is a thermostatic expansion valve connected between the condenser and the evaporator, the outlet of the thermostatic expansion valve is connected to the evaporator, the temperature sensing bulb of the thermostatic expansion valve detects the temperature at the outlet of the evaporator, and the differential pressure regulating valve is located between the inlet of the thermostatic expansion valve and the condenser.

[0008] In some embodiments, the differential pressure regulating valve includes a differential pressure valve body, a differential pressure valve core located in the differential pressure valve body, and an elastic device connected to the differential pressure valve core. The inlet and outlet of the differential pressure valve body are respectively connected to the condenser and the evaporator. The pressure at the inlet of the differential pressure valve body causes the differential pressure valve core to tend to move in the direction of closing the differential pressure regulating valve, and the pressure at the outlet of the differential pressure valve body and the elastic force of the elastic device on the differential pressure valve core cause the differential pressure valve core to tend to move in the direction of opening the differential pressure regulating valve.

[0009] In some embodiments, the second throttling flow path further includes an on / off valve connected in series with the differential pressure regulating valve and the second throttling element for controlling the on / off state of the second throttling flow path.

[0010] In some embodiments, the first throttling element is a thermostatic expansion valve.

[0011] In some embodiments, a third throttling flow path is further included, connected between the condenser and the evaporator, the inlet and outlet of the third throttling flow path being connected to the inlet and outlet of the first throttling flow path, respectively, and the third throttling flow path including a throttling orifice plate for throttling the refrigerant.

[0012] In some embodiments, a reservoir is also included connected between the condenser and the throttling device.

[0013] In some embodiments, the differential pressure regulating valve is an adjustable differential pressure regulating valve with a first threshold adjustable.

[0014] In some embodiments, the system includes two compressors, two throttling devices, an evaporator, and a condenser. The two compressors include a first compressor and a second compressor. The two throttling devices include a first throttling device and a second throttling device. The inlets of the first throttling device and the second throttling device are interconnected and simultaneously connected to the outlet of the condenser. The evaporator has independent first and second pipes. The first pipe connects the outlet of the first throttling device to the inlet of the first compressor. The second pipe connects the outlet of the second throttling device to the inlet of the second compressor. The outlets of the first compressor and the second compressor are interconnected and connected to the inlet of the condenser.

[0015] A second aspect of the present invention discloses an air conditioning system, including any of the aforementioned refrigeration cycle systems.

[0016] In some embodiments, the air conditioning system is a water-cooled screw chiller unit.

[0017] Based on the refrigeration cycle system provided by this invention, a second throttling flow path is set in parallel with the first throttling flow path, and a differential pressure regulating valve and a second throttling element are set in series on the second throttling flow path. When the pressure difference between the inlet and outlet of the differential pressure regulating valve is less than a first threshold, the fluid passage of the differential pressure regulating valve opens, and the second and first throttling elements jointly throttle the refrigerant output from the condenser to the evaporator. When the pressure difference between the inlet and outlet of the differential pressure regulating valve is greater than the first threshold, the fluid passage of the differential pressure regulating valve closes, the second throttling element does not participate in throttling, and only the first throttling element throttles the refrigerant output from the condenser to the evaporator. Therefore, when the heat load temperature on the evaporator side is high and the superheat at the evaporator outlet is high, the differential pressure regulating valve can be automatically opened, and the throttling device has a large throttling capacity. When the heat load temperature on the evaporator side is low and the superheat at the evaporator outlet is low, the fluid passage of the differential pressure regulating valve closes, and the throttling device has a smaller throttling capacity, which can better match the heat load on the evaporator side. At the same time, by using hydraulic components to adjust the throttling capacity, it can be more safely applied to special occasions where the use of electrical signals is prohibited.

[0018] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0020] Figure 1This is a schematic diagram illustrating the structural principle of the refrigeration cycle system according to an embodiment of the present invention;

[0021] Figure 2 for Figure 1 The diagram shows an enlarged schematic of the differential pressure regulating valve in the refrigeration cycle system. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0024] In the description of this invention, it should be understood that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0027] like Figure 1 As shown, the refrigeration cycle system of this embodiment includes a compressor 1, a condenser 2, an evaporator 4, and at least one throttling device 3 connected between the condenser 2 and the evaporator 4. Correspondingly, the compressor 1, the condenser 2, the evaporator 4, and the throttling device 3 are used to complete the compression process, condensation process, evaporation process, and expansion process (throttling process) of the refrigerant in the refrigeration cycle, respectively.

[0028] The throttling device 3 includes a first throttling flow path 31 and a second throttling flow path 32. The first throttling flow path 31 is connected between the condenser 2 and the evaporator 4, and the first throttling flow path 31 includes a first throttling element 311 for throttling and expanding the refrigerant.

[0029] As shown in the figure, the second throttling flow path 32 is connected between the condenser 2 and the evaporator 4, and its inlet and outlet are connected in parallel with the inlet and outlet of the first throttling flow path 31, respectively. That is, the inlet of the second throttling flow path 32 is connected to the inlet of the first throttling flow path 31, and the outlet of the second throttling flow path 32 is connected to the outlet of the first throttling flow path 31. The second throttling flow path 32 includes a differential pressure regulating valve 322 and a second throttling element 321 connected in series. Specifically, the inlet of the differential pressure regulating valve 322 is connected to the outlet of the second throttling element 321, or vice versa. When the pressure difference between the inlet and outlet of the differential pressure regulating valve 322 is less than a first threshold, the fluid passage of the differential pressure regulating valve 322 opens, the fluid passage of the second throttling flow path 32 opens, and the second throttling element 321 can then exert its throttling capability on the refrigerant. The first threshold is the opening pressure difference value of the differential pressure regulating valve 322. The first threshold of the differential pressure regulating valve 322 can be designed to be either non-adjustable or adjustable. When the pressure difference between the inlet and outlet of the differential pressure regulating valve 322 is greater than the first threshold, the fluid passage of the differential pressure regulating valve 322 is closed, and the second throttling flow path 32 does not perform its throttling function. The inlet of the differential pressure regulating valve 322 is connected to the condenser, and the outlet of the differential pressure regulating valve 322 is connected to the evaporator. When the heat load temperature on the evaporator side rises, the superheat at the outlet of the evaporator increases, the pressure of the refrigerant in the evaporator increases, and thus the outlet pressure of the differential pressure regulating valve 322 increases, and the pressure difference between the inlet and outlet of the differential pressure regulating valve 322 decreases. When it decreases to the designed first threshold, the fluid passage of the differential pressure regulating valve 322 automatically opens, thereby automatically and better meeting the cooling requirements of the heat load. In the embodiment shown in the figure, the heat load is chilled water flowing in from the evaporator heat exchange inlet 41 of the evaporator 4. After exchanging heat with the refrigerant in the evaporator, the chilled water flows out from the evaporator heat exchange outlet 42.

[0030] In this embodiment of the refrigeration cycle system, a second throttling flow path 32 is set in parallel with the first throttling flow path 31, and a differential pressure regulating valve 322 and a second throttling element 321 are connected in series on the second throttling flow path 32. Thus, when the pressure difference between the inlet and outlet of the differential pressure regulating valve 322 is less than a first threshold, the differential pressure regulating valve 322 automatically opens, and the second throttling element 321 and the first throttling element 311 together throttle the refrigerant output from the condenser 2 to the evaporator 4. When the pressure difference between the inlet and outlet of the differential pressure regulating valve 322 is greater than the first threshold, the differential pressure regulating valve 322 automatically closes the fluid passage. The second throttling element 321 does not participate in throttling; only the first throttling element 311 throttles the refrigerant output from the condenser 2 to the evaporator 4. Therefore, when the heat load temperature on the evaporator 4 side is high and the superheat at the evaporator 4 outlet is high, the differential pressure regulating valve 322 can open, giving the throttling device 3 a large throttling capacity. When the heat load temperature on the evaporator 4 side is low and the superheat at the evaporator 4 outlet is low, the differential pressure regulating valve 322 automatically closes the fluid passage, giving the throttling device 3 a smaller throttling capacity. This prevents excessive throttling from increasing the liquid content of the refrigerant output from the evaporator to the compressor, which could damage the compressor. Furthermore, by using hydraulic components to adjust the throttling capacity, it is safer to apply to special applications where the use of electrical signals is prohibited.

[0031] In some embodiments, as shown in the figure, the second throttling element 321 is a thermostatic expansion valve connected between the condenser 2 and the evaporator 4. The outlet of the thermostatic expansion valve is connected to the evaporator 4, and the temperature sensing bulb of the thermostatic expansion valve detects the temperature at the outlet of the evaporator 4. A differential pressure regulating valve 322 is located between the inlet of the thermostatic expansion valve and the condenser 2. When the differential pressure regulating valve 322 is closed, the refrigerant does not flow between the inlet and outlet of the thermostatic expansion valve on the second throttling flow path 32, the thermostatic expansion valve does not produce a throttling effect, and there is no pressure difference between the inlet and outlet of the thermostatic expansion valve. The pressure at the outlet of the differential pressure regulating valve 322 connected to the inlet of the thermostatic expansion valve is also the refrigerant pressure at the inlet of the evaporator. When the heat load temperature of the evaporator increases, the differential pressure regulating valve opens, and the thermostatic expansion valve on the second throttling flow path 32 begins to throttle the refrigerant together with the first throttling element. The thermostatic expansion valve can adjust the flow rate of the refrigerant entering the evaporator according to the temperature of the temperature sensing bulb.

[0032] In some embodiments, such as Figure 1 and Figure 2As shown, the differential pressure regulating valve 322 includes a differential pressure valve body 3221, a differential pressure valve core 3222 located in the differential pressure valve body 3221, and an elastic device 3223 connected to the differential pressure valve core 3222. The inlet 3224 and outlet 3225 of the differential pressure valve body are connected to the condenser 2 and the evaporator 4, respectively. The pressure at the inlet 3224 of the differential pressure valve body causes the differential pressure valve core 3222 to tend to move towards closing the differential pressure regulating valve 322. The pressure at the outlet 3225 of the differential pressure valve body and the elastic force of the elastic device 3223 on the differential pressure valve core 3222 cause the differential pressure valve core 3222 to tend to move towards opening the differential pressure regulating valve 322. In the embodiment shown, the elastic device is an adjustable spring connected between the differential pressure valve body 3221 and the differential pressure valve core 3222. The differential pressure regulating valve 322 is an adjustable differential pressure regulating valve 322 with an adjustable first threshold. The first threshold of the differential pressure regulating valve 322 can be adjusted by adjusting the preload of the adjustable spring.

[0033] In some embodiments, the second throttling flow path 32 further includes an on / off valve 323 connected in series with the differential pressure regulating valve 322 and the second throttling element 321 for controlling the on / off state of the second throttling flow path 32. The on / off valve 323 can additionally control the on / off state of the second throttling flow path 32. In the embodiment shown in the figure, the on / off valve 323 is a ball valve.

[0034] In some embodiments, the first throttling element 311 is a thermostatic expansion valve.

[0035] In some embodiments, the refrigeration cycle system further includes a third throttling flow path 33 connected between the condenser 2 and the evaporator 4. The inlet and outlet of the third throttling flow path 33 are connected to the inlet and outlet of the first throttling flow path 31, respectively. The third throttling flow path 33 includes a throttling orifice plate for throttling the refrigerant. Providing a third throttling flow path increases the throttling capacity of the throttling device under normal operating conditions. When the differential pressure regulating valve is closed, the throttling orifice plate of the third throttling flow path 33 and the first throttling element of the first throttling flow path together throttle the refrigerant. When the differential pressure regulating valve is open, the first throttling element, the second throttling element, and the throttling orifice plate together throttle the refrigerant.

[0036] In some embodiments, the refrigeration cycle system further includes a receiver 5 connected between the condenser 2 and the throttling device 3. The receiver stores refrigerant, which flows from the condenser into the receiver 5 and then from the receiver 5 to the throttling device. The receiver also compensates for changes in the condenser liquid level due to load variations. In some embodiments, the receiver can also serve as an additional container to help separate the liquid refrigerant from the refrigerant vapor, ensuring that only pure liquid refrigerant leaves the receiver.

[0037] In some embodiments, such as Figure 1As shown, the refrigeration cycle system includes two compressors 1, two throttling devices 3, an evaporator 4, and a condenser 2. The two compressors 1 include a first compressor and a second compressor. The two throttling devices 3 include a first throttling device and a second throttling device. The inlets of the first and second throttling devices are interconnected and simultaneously connected to the outlet of the condenser 2. The evaporator 4 has independent first and second pipes. The first pipe connects the outlet of the first throttling device to the inlet of the first compressor, and the second pipe connects the outlet of the second throttling device to the inlet of the second compressor. The outlets of the first and second compressors are interconnected and connected to the inlet of the condenser 2. In the embodiment shown, the two compressors share a single condenser 2 to dissipate heat from the refrigerant. After the refrigerant is throttled by two sets of throttling devices, it enters the evaporator through two independent pipes for heat exchange with the heat load. This significantly improves the cooling and heat exchange capacity of the heat load, enhances the refrigeration effect, and improves the utilization efficiency of system components. The system is compact and easy to arrange.

[0038] In some embodiments, an air conditioning system is also disclosed, including any of the above-described refrigeration cycle systems.

[0039] In some embodiments, the air conditioning system includes a water-cooled screw chiller. A water-cooled screw chiller is a type of chiller whose main component uses a screw compressor. The chilled water is cooled by heat exchange at the evaporator 4, and cooling water enters the condenser 2 through the condenser heat dissipation inlet 21 to cool the refrigerant. The cooled water is then discharged from the condenser heat dissipation outlet 22.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A refrigeration cycle system comprising a compressor (1), a condenser (2), an evaporator (4), and at least one throttling device (3) connected between the condenser (2) and the evaporator (4), characterized in that, The throttling device (3) includes: The first throttling flow path (31) is connected between the condenser (2) and the evaporator (4), and includes a first throttling element (311), which is a thermal expansion valve; The second throttling flow path (32) is connected between the condenser (2) and the evaporator (4), and its inlet and outlet are connected in parallel with the inlet and outlet of the first throttling flow path (31), respectively. The second throttling flow path (32) includes a differential pressure regulating valve (322) and a second throttling element (321) connected in series. When the pressure difference between the inlet and outlet of the differential pressure regulating valve (322) is less than a first threshold, the fluid passage of the differential pressure regulating valve (322) is opened. When the pressure difference between the inlet and outlet of the differential pressure regulating valve (322) is greater than the first threshold, the fluid passage of the differential pressure regulating valve (322) is closed.

2. The refrigeration cycle system as described in claim 1, characterized in that, The second throttling element (321) is a thermostatic expansion valve connected between the condenser (2) and the evaporator (4). The outlet of the thermostatic expansion valve is connected to the evaporator (4). The temperature sensing bulb of the thermostatic expansion valve detects the temperature at the outlet of the evaporator (4). The differential pressure regulating valve (322) is located between the inlet of the thermostatic expansion valve and the condenser (2).

3. The refrigeration cycle system as described in claim 1 or 2, characterized in that, The differential pressure regulating valve (322) includes a differential pressure valve body (3221), a differential pressure valve core (3222) located in the differential pressure valve body (3221), and an elastic device (3223) connected to the differential pressure valve core (3222). The inlet and outlet of the differential pressure valve body are connected to the condenser (2) and the evaporator (4), respectively. The pressure at the inlet of the differential pressure valve body causes the differential pressure valve core (3222) to tend to move in the direction of closing the differential pressure regulating valve (322). The pressure at the outlet of the differential pressure valve body and the elastic force of the elastic device (3223) on the differential pressure valve core (3222) cause the differential pressure valve core (3222) to tend to move in the direction of opening the differential pressure regulating valve (322).

4. The refrigeration cycle system as described in claim 1 or 2, characterized in that, The second throttling flow path (32) also includes an on / off valve (323) connected in series with the differential pressure regulating valve (322) and the second throttling element (321) for controlling the on / off state of the second throttling flow path (32).

5. The refrigeration cycle system as described in claim 1 or 2, characterized in that, It also includes a third throttling flow path (33) connected between the condenser (2) and the evaporator (4), the inlet and outlet of the third throttling flow path (33) being connected to the inlet and outlet of the first throttling flow path (31) respectively, and the third throttling flow path (33) including a throttling orifice plate (331) for throttling the refrigerant.

6. The refrigeration cycle system as described in claim 1 or 2, characterized in that, It also includes a reservoir (5) connected between the condenser (2) and the throttling device (3).

7. The refrigeration cycle system as described in claim 1 or 2, characterized in that, The differential pressure regulating valve (322) is an adjustable differential pressure regulating valve (322) with a first threshold adjustable.

8. The refrigeration cycle system as described in claim 1 or 2, characterized in that, It includes two compressors (1), two throttling devices (3), an evaporator (4), and a condenser (2). The two compressors (1) include a first compressor and a second compressor. The two throttling devices (3) include a first throttling device and a second throttling device. The inlets of the first throttling device and the second throttling device are interconnected and simultaneously connected to the outlet of the condenser (2). The evaporator (4) is provided with a first pipeline and a second pipeline that are independent of each other. The first pipeline connects the outlet of the first throttling device and the inlet of the first compressor. The second pipeline connects the outlet of the second throttling device and the inlet of the second compressor. The outlet of the first compressor and the outlet of the second compressor are interconnected and connected to the inlet of the condenser (2).

9. An air conditioning system, characterized in that, Includes the refrigeration cycle system as described in any one of claims 1 to 8.

10. The air conditioning system as described in claim 9, characterized in that, The air conditioning system includes a water-cooled screw chiller unit.

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