Screw refrigerating unit

Abstract

The utility model discloses a screw refrigerating unit which comprises a screw compressor, an oil separator and an oil cooler, the oil separator is connected with an outlet of the screw compressor, and the oil separator is provided with an oil port and a refrigerant port for discharging refrigerant. The oil cooler is provided with an oil inlet, an oil outlet, a refrigerant inlet allowing a refrigerant to enter and a refrigerant outlet allowing the refrigerant to be discharged, the oil inlet is connected with the oil port, and the oil outlet is connected with the screw compressor; the refrigerant inlet is provided with an electric valve, the oil outlet is provided with a temperature monitoring device, and the temperature monitoring device is in signal connection with the electric valve. According to the screw refrigerating unit, the temperature fluctuation range of engine oil cooled by the oil cooler can be reduced, so that the energy loss of the screw refrigerating unit is reduced, and the operation condition of the screw refrigerating unit is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of refrigeration units, specifically to a screw refrigeration unit. Background Technology

[0002] As a core piece of equipment in the industrial refrigeration field, the operating efficiency and stability of screw chiller units are crucial for ensuring the continuity of the production process and product quality. The core component of a screw chiller unit is the screw compressor (also known as the compressor head). After being compressed by the screw compressor, the refrigerant first enters an oil separator to separate refrigerant and oil. The refrigerant then enters the economizer, while the oil returns to the screw compressor after passing through an oil cooler. During this process, oil temperature control is greatly affected by ambient temperature, requiring frequent and cumbersome manual adjustments. Furthermore, this leads to significant oil temperature fluctuations, resulting in substantial energy loss and impacting the operating conditions of the screw chiller unit. Utility Model Content

[0003] This utility model aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of this utility model propose a screw chiller unit that can reduce the temperature fluctuation of the oil after cooling by the oil cooler, thereby reducing the energy loss of the screw chiller unit and improving its operating conditions.

[0005] The screw refrigeration unit of this utility model embodiment includes a screw compressor, an oil separator, and an oil cooler. The oil separator is connected to the outlet of the screw compressor and has an oil port and a refrigerant port for refrigerant discharge. The oil cooler has an oil inlet, an oil outlet, a refrigerant inlet for refrigerant entry, and a refrigerant outlet for refrigerant discharge. The oil inlet is connected to the oil port, and the oil outlet is connected to the screw compressor. The refrigerant inlet is equipped with an electric valve, and the oil outlet is equipped with a temperature monitoring device, which is signal-connected to the electric valve.

[0006] In some embodiments, the refrigerant inlet is provided with a refrigerant inlet pipe, and the electric valve is connected to the refrigerant inlet pipe.

[0007] In some embodiments, the electric valve is connected to the refrigerant inlet pipe via a flange.

[0008] In some embodiments, the oil outlet is provided with an oil outlet pipe, and the temperature monitoring device is connected to the oil outlet pipe.

[0009] In some embodiments, the temperature monitoring device is a temperature sensor.

[0010] In some embodiments, the temperature sensor is detachably connected to the oil outlet pipe.

[0011] In some embodiments, the screw compressor unit further includes a cooler, an economizer, an evaporator, and a gas-liquid separator connected in sequence, wherein the refrigerant port of the oil separator is connected to the inlet of the cooler, and the outlet of the gas-liquid separator is connected to the screw compressor.

[0012] In some embodiments, the economizer includes a gas phase tube, one end of which is connected to the inlet of the gas-liquid separator.

[0013] In some embodiments, a three-way pipe is provided between the evaporator and the gas-liquid separator. The three-way pipe has a first connection port, a second connection port and a third connection port. The first connection port is connected to the evaporator, the second connection port is connected to the gas-liquid separator, and the third connection port is connected to the gas phase pipe.

[0014] In this embodiment of the screw refrigeration unit, the refrigerant is compressed by the screw compressor to form an oil-gas mixture. The refrigerant and oil are separated by an oil separator. The separated oil flows through an oil cooler and is cooled by the refrigerant before flowing back into the screw compressor, and the cycle continues.

[0015] The screw chiller unit of this utility model can monitor the oil temperature of the oil discharged from the oil outlet of the oil cooler in real time through a temperature monitoring device. Based on the oil temperature, the opening of the electric valve is controlled, and then the amount of refrigerant flowing through the oil cooler is controlled to control the oil temperature. This makes the temperature fluctuation of the oil after being cooled by the oil cooler smaller, thereby reducing the energy loss of the screw chiller unit and improving the operating conditions of the screw chiller unit. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process of a screw chiller unit according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram showing the connection of the evaporator, gas-liquid separator, and gas phase pipe of a screw chiller unit according to an embodiment of this utility model.

[0018] Figure label:

[0019] 100. Screw chiller unit;

[0020] 1. Screw compressor;

[0021] 2. Oil separator; 21. Oil port; 22. Refrigerant port;

[0022] 3. Oil cooler; 31. Oil inlet; 32. Oil outlet; 321. Oil outlet pipe; 33. Refrigerant inlet; 331. Refrigerant inlet pipe; 34. Refrigerant outlet;

[0023] 41. Electric valve; 42. Temperature sensor;

[0024] 5. Cooler;

[0025] 6. Economizer; 61. Gas phase tube;

[0026] 7. Evaporator;

[0027] 8. Gas-liquid separator;

[0028] 9. T-joint; 91. First connection port; 92. Second connection port; 93. Third connection port. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] like Figure 1 As shown, the screw refrigeration unit 100 of this utility model embodiment includes a screw compressor 1, an oil separator 2, and an oil cooler 3. The oil separator 2 is connected to the outlet of the screw compressor 1 and has an oil port 21 and a refrigerant port 22 for refrigerant discharge. The oil cooler 3 has an oil inlet 31, an oil outlet 32, a refrigerant inlet 33 for refrigerant entry, and a refrigerant outlet 34 for refrigerant discharge. The oil inlet 31 is connected to the oil port 21, and the oil outlet 32 ​​is connected to the screw compressor 1. The refrigerant inlet 33 is equipped with an electric valve 41, and the oil outlet 32 ​​is equipped with a temperature monitoring device. The temperature monitoring device is signal-connected to the electric valve 41.

[0031] In the screw compressor 100 of this utility model embodiment, the refrigerant is compressed by the screw compressor 1 to form a mixture of refrigerant and oil. The mixture is separated into refrigerant and oil by the oil separator 2. The separated oil flows through the oil cooler 3 and is cooled by the refrigerant, and then flows back into the screw compressor 1, and so on.

[0032] The screw chiller unit 100 of this utility model embodiment can monitor the oil temperature of the oil discharged from the oil outlet 32 ​​of the oil cooler 3 in real time through a temperature monitoring device. Based on the oil temperature, the opening degree of the electric valve 41 is controlled, and the amount of refrigerant flowing through the oil cooler 3 is controlled to control the oil temperature. This makes the temperature fluctuation of the oil after being cooled by the oil cooler 3 smaller, thereby reducing the energy loss of the screw chiller unit 100, improving the operating conditions of the screw chiller unit 100, and enabling the screw chiller unit 100 to operate stably at full load under rated operating conditions.

[0033] For example, when the ambient temperature is low, the engine oil temperature is too low. The oil temperature monitoring device sends a signal to the electric valve 41, controlling the opening of the electric valve 41 to decrease the amount of refrigerant flowing through the oil cooler 3, thereby increasing the oil temperature. When the ambient temperature is low, the engine oil temperature is too high. The oil temperature monitoring device sends a signal to the electric valve 41, controlling the opening of the electric valve 41 to increase the amount of refrigerant flowing through the oil cooler 3, thereby decreasing the oil temperature. In this way, the oil temperature can be controlled within a certain range, reducing the fluctuation range of the oil temperature.

[0034] Before the temperature monitoring device and electric valve 41 were installed, the oil temperature fluctuated between 20°C and 55°C; in this embodiment of the present invention, the oil temperature fluctuates between 40°C and 50°C.

[0035] Optionally, the refrigerant is R22.

[0036] Optionally, the refrigerant for the oil cooler 3 is water.

[0037] In some embodiments, such as Figure 1 As shown, the refrigerant inlet 33 is equipped with a refrigerant inlet pipe 331, and the electric valve 41 is connected to the refrigerant inlet pipe 331.

[0038] In some embodiments, the electric valve 41 is connected to the refrigerant inlet pipe 331 via a flange.

[0039] The electric valve 41 and the refrigerant inlet pipe 331 are detachably connected by a flange and multiple bolt assemblies, which makes it easier to disassemble and install the electric valve 41 for maintenance.

[0040] Of course, in other embodiments, the electric valve 41 and the refrigerant inlet pipe 331 can also be connected by threaded connection, welding or other methods.

[0041] In some embodiments, such as Figure 1 As shown, the oil outlet 32 ​​is equipped with an oil outlet pipe 321, and the temperature monitoring device is connected to the oil outlet pipe 321.

[0042] In some embodiments, the temperature monitoring device is a temperature sensor 42.

[0043] The temperature sensor 42 has high accuracy and can realize real-time monitoring and accurate detection of oil temperature. In turn, the temperature sensor 42 can realize accurate and real-time control of the opening degree of electric valve 41, thereby ensuring the stable operation of the screw chiller unit 100.

[0044] In some embodiments, the temperature sensor 42 is detachably connected to the oil outlet pipe 321.

[0045] With the above settings, the temperature sensor 42 can be detached and installed, which makes it easier to remove and install the temperature sensor 42, so as to facilitate the maintenance of the temperature sensor 42.

[0046] In some embodiments, such as Figure 1 As shown, the screw compressor unit 100 also includes a cooler 5, an economizer 6, an evaporator 7, and a gas-liquid separator 8 connected in sequence. The refrigerant port 22 of the oil separator 2 is connected to the inlet of the cooler 5, and the outlet of the gas-liquid separator 8 is connected to the screw compressor 1.

[0047] After being compressed by the screw compressor 1, the refrigerant forms a mixture of liquid refrigerant and oil. This mixture is separated into liquid refrigerant and oil by the oil separator 2. The oil is cooled by the oil cooler 3 and then flows back into the screw compressor 1. The liquid refrigerant flows through the cooler 5 and the economizer 6 in sequence to be cooled down. After evaporating and absorbing heat by the evaporator 7, it becomes gaseous. It is then separated into gas and liquid by the gas-liquid separator 8, so that the refrigerant returns to the screw compressor 1 in gaseous state. This cycle continues.

[0048] In this embodiment of the invention, by setting a temperature monitoring device and an electric valve 41, the fluctuation range of oil temperature can be reduced and the stability of oil temperature can be improved. At the same time, since the oil temperature entering the screw compressor 1 is relatively stable, the oil temperature has little impact on the refrigerant temperature inside the screw compressor 1, resulting in a smaller fluctuation range of refrigerant temperature exiting the screw compressor 1. This further reduces the fluctuation range of the liquid supply temperature (the liquid supply temperature is the temperature of the liquid refrigerant from the economizer 6 to the evaporator 7), thereby improving the operating conditions of the screw refrigeration unit 100.

[0049] Specifically, before the temperature monitoring device and electric valve 41 are installed, the fluctuation range of the liquid supply temperature is -7℃ to 2℃. In this embodiment of the present invention, the fluctuation range of the liquid supply temperature is 0℃ to 3℃.

[0050] Both cooler 5 and economizer 6 are used to cool and lower the refrigerant. The refrigerant in cooler 5 is water, and the refrigerant in economizer 6 is R22. The liquid refrigerant first passes through cooler 5 for initial cooling and then passes through economizer 6 for further cooling and lowering, which can reduce the amount of R22 used and achieve energy-saving effect on R22.

[0051] The function of the gas-liquid separator 8 is to separate the liquid refrigerant from the gaseous refrigerant to prevent the liquid refrigerant from entering the screw compressor 1.

[0052] In this embodiment of the invention, when the ambient temperature is high, the evaporator 7 can basically achieve the vaporization of all liquid refrigerant; when the ambient temperature is low, adding electric heating to the liquid refrigerant can achieve the vaporization of all liquid refrigerant.

[0053] In some embodiments, such as Figure 1 and Figure 2 As shown, the economizer 6 includes a gas phase pipe 61, the end of which is away from the economizer 6 and connected to the inlet of the gas-liquid separator 8.

[0054] It is known that in related technologies, the vapor phase pipe 61 of the economizer 6 is connected to the screw compressor 1, that is, part of the liquid refrigerant is throttled and evaporated twice in the economizer 6, and the generated gas is returned to the screw compressor 1 through the vapor phase pipe 61 to replenish the screw compressor 1; however, the direct return of gas from the economizer 6 to the screw compressor 1 can easily cause unstable suction pressure and large load fluctuations in the screw compressor 1, affecting the operating conditions of the screw refrigeration unit 100.

[0055] In this embodiment of the present invention, the gaseous refrigerant in the economizer 6 returns to the gas-liquid separator 8 through the gas phase pipe 61. The gas-liquid separator 8 can play a buffering role, thereby making the suction pressure of the screw compressor 1 more stable, reducing load fluctuations, and thus improving the operating conditions of the screw refrigeration unit 100.

[0056] In some embodiments, such as Figure 2 As shown, a three-way pipe 9 is provided between the evaporator 7 and the gas-liquid separator 8. The three-way pipe 9 has a first connection port 91, a second connection port 92 and a third connection port 93. The first connection port 91 is connected to the evaporator 7, the second connection port 92 is connected to the gas-liquid separator 8, and the third connection port 93 is connected to the gas phase pipe 61.

[0057] The outlet of the evaporator 7, the inlet of the gas-liquid separator 8, and the gas phase pipe 61 can be stably connected through the three-way pipe 9.

[0058] Optionally, the first connection port 91, the second connection port 92, and the third connection port 93 of the tee pipe 9 are all provided with threaded connection structures.

[0059] Therefore, the outlet of evaporator 7, the inlet of gas-liquid separator 8, and the gas phase pipe 61 are all detachably connected to the three-way pipe 9 through a threaded connection structure, which makes maintenance work more convenient.

[0060] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0063] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0064] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0065] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A screw chiller unit (100), characterized in that, The system includes a screw compressor (1), an oil separator (2), and an oil cooler (3). The oil separator (2) is connected to the outlet of the screw compressor (1). The oil separator (2) has an oil port (21) and a refrigerant port (22) for refrigerant discharge. The oil cooler (3) has an oil inlet (31), an oil outlet (32), a refrigerant inlet (33) for refrigerant entry, and a refrigerant outlet (34) for refrigerant discharge. The oil inlet (31) is connected to the oil port (21), and the oil outlet (32) is connected to the screw compressor (1). The refrigerant inlet (33) is equipped with an electric valve (41), and the oil outlet (32) is equipped with a temperature monitoring device. The temperature monitoring device is signal-connected to the electric valve (41).

2. The screw chiller unit (100) according to claim 1, characterized in that, The refrigerant inlet (33) is provided with a refrigerant inlet pipe (331), and the electric valve (41) is connected to the refrigerant inlet pipe (331).

3. The screw chiller unit (100) according to claim 2, characterized in that, The electric valve (41) is connected to the refrigerant inlet pipe (331) via a flange.

4. The screw chiller unit (100) according to claim 1, characterized in that, The oil outlet (32) is provided with an oil outlet pipe (321), and the temperature monitoring device is connected to the oil outlet pipe (321).

5. The screw chiller unit (100) according to claim 4, characterized in that, The temperature monitoring device is a temperature sensor (42).

6. The screw chiller unit (100) according to claim 5, characterized in that, The temperature sensor (42) is detachably connected to the oil outlet pipe (321).

7. The screw chiller unit (100) according to any one of claims 1-6, characterized in that, It also includes a cooler (5), an economizer (6), an evaporator (7) and a gas-liquid separator (8) connected in sequence. The refrigerant port (22) of the oil separator (2) is connected to the inlet of the cooler (5), and the outlet of the gas-liquid separator (8) is connected to the screw compressor (1).

8. The screw chiller unit (100) according to claim 7, characterized in that, The economizer (6) includes a gas phase pipe (61), one end of which is connected to the inlet of the gas-liquid separator (8) away from the economizer (6).

9. The screw chiller unit (100) according to claim 8, characterized in that, A three-way pipe (9) is provided between the evaporator (7) and the gas-liquid separator (8). The three-way pipe (9) has a first connection port (91), a second connection port (92) and a third connection port (93). The first connection port (91) is connected to the evaporator (7), the second connection port (92) is connected to the gas-liquid separator (8), and the third connection port (93) is connected to the gas phase pipe (61).

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