Oil return device of centrifugal refrigerator

Abstract

One end of the oil return device of the centrifugal refrigerator is connected with an inlet pipeline, the other end of the oil return device is connected with an evaporator, and the oil return device receives oil-gas mixed liquid from the inlet pipeline and separates the oil-gas mixed liquid. The device comprises a low-pressure machine which is connected with an inlet pipeline and is used for receiving oil-gas mixed liquid and carrying out primary separation on the oil-gas mixed liquid; and the high-pressure machine is respectively connected with the low-pressure machine and the evaporator and is used for receiving the primarily separated liquid and carrying out secondary separation on the primarily separated liquid. Oil gas which is not separated flows back to the oil collector and then is pressed back into the unit, so that the effect of no oil leakage is achieved, and oil leakage is reduced by 60% compared with oil leakage before transformation.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, and in particular to an oil return device for a centrifugal refrigeration machine. Background Technology

[0002] In the operation of the original centrifugal chiller, the lubricating oil and Freon come into contact, playing a role in cooling, sealing and lubrication. When the oil temperature is low, the separation effect of lubricating oil and Freon is poor. The lubricating oil is carried with Freon to the evaporator and other refrigeration systems, which leads to the inability to recover the lubricating oil normally. At the same time, the unit is short of oil and the heat exchange effect of the evaporator decreases, making it unable to reach the design conditions. Utility Model Content

[0003] The purpose of this invention is to provide an oil return device for a centrifugal refrigeration machine, which has the advantages of separating gas and liquid and returning oil.

[0004] To achieve the above objectives, this utility model provides an oil return device for a centrifugal chiller. One end of the device is connected to an inlet pipe, and the other end is connected to an evaporator. The device receives and separates an oil-gas mixture from the inlet pipe. The device includes: a low-pressure compressor connected to the inlet pipe, receiving the oil-gas mixture and performing preliminary separation; and a high-pressure compressor connected to both the low-pressure compressor and the evaporator, receiving the pre-separated liquid and performing secondary separation. The low-pressure compressor includes at least one filter screen located at the connection between the low-pressure and high-pressure compressors for preliminary liquid separation. The high-pressure compressor includes an oil collector for secondary separation of the pre-separated liquid and a liquid inlet located on the surface of the high-pressure compressor, which extracts the oil-gas mixture collected by the oil collector in the high-pressure compressor.

[0005] Preferably, the low-pressure compressor further includes a low-pressure compressor oil tank, which is located at the bottom of the low-pressure compressor, connected to all filters, and receives and stores the oil collected from the filters.

[0006] Preferably, the high-pressure machine further includes a high-pressure machine oil tank, which is located at the bottom of the high-pressure machine and connected to an oil collector and a liquid inlet, respectively, to receive and store the oil separated in the secondary process.

[0007] Preferably, the device further includes: an oil tank balance pipe, which is connected to the low-pressure oil tank and the high-pressure oil tank respectively, so that the low-pressure oil tank and the high-pressure oil tank maintain the same pressure inside.

[0008] Preferably, the device further includes: a first balancing pipe, which is connected to the low-pressure machine and the high-pressure machine (8) respectively, to balance the internal pressure in real time.

[0009] Preferably, the device further includes: a second balancing pipe, which is connected to the high-pressure machine and the inlet pipe (4) respectively, so that the pressure of the low-pressure machine, the high-pressure machine and the inlet pipe are balanced.

[0010] Preferably, both the first and second balance tubes are equipped with several pressure valves, which can automatically open when the internal pressure is too high.

[0011] Preferably, the device further includes a drive unit, which is connected to the low-pressure generator and the high-pressure generator respectively, and provides drive for the low-pressure generator and the high-pressure generator.

[0012] In summary, compared with the prior art, the oil return device for a centrifugal chiller provided by this utility model has the following beneficial effects:

[0013] First, add a filter screen to filter and block the oil and gas mixture in the Freon from entering the low-pressure oil tank. At the same time, add a liquid collection point on the high-pressure machine head to ensure that the lubricating oil and Freon can be separated, so that the lubricating oil will not enter the evaporator with the Freon and clog the system, thus affecting the heat exchange effect.

[0014] Secondly, this utility model returns the unseparated oil and gas to the oil collector and then pressurizes it back into the unit, thereby achieving the effect of no oil leakage, reducing oil leakage by 60% compared to before the modification. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an oil return device for a centrifugal refrigeration machine proposed in this utility model.

[0016] Figure label:

[0017] 1-Low-pressure compressor, 2-Filter screen, 3-Low-pressure compressor oil tank, 4-Inlet pipe, 5-Oil tank balance pipe, 6-High-pressure compressor oil tank, 7-Liquid outlet, 8-High-pressure compressor, 9-Oil collector, 10-First balance pipe, 11-Second balance pipe, 12-Drive device. Detailed Implementation

[0018] The following will be combined with the appendix in the embodiments of this utility model. Figure 1 The technical solutions, structural features, objectives and effects achieved in the embodiments of this utility model are described in detail.

[0019] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the illustration of the embodiments of this utility model, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in this utility model, provided that they do not affect the effects and objectives that this utility model can produce.

[0020] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0021] This invention provides an oil return device for a centrifugal chiller. One end of the device is connected to an inlet pipe 4, and the other end is connected to an evaporator (not shown). The device can receive a mixture of oil and gas (generally from the chiller) from the inlet pipe 4. For example, a mixture of lubricating oil and Freon from the chiller can be separated by this device.

[0022] like Figure 1 As shown, the device includes:

[0023] Low-pressure unit 1 is connected to inlet pipe 4 to receive the oil-gas mixture and perform preliminary separation on it;

[0024] High pressure unit 8 is connected to low pressure unit 1 and evaporator respectively, and receives the liquid after preliminary separation and performs secondary separation on it;

[0025] The low-pressure unit 1 includes at least one filter screen 2, which is disposed at the connection between the low-pressure unit 1 and the high-pressure unit 8 to perform preliminary separation of the liquid;

[0026] The high-pressure unit 8 includes:

[0027] Oil collector 9 performs secondary separation on the liquid after initial separation to collect oil and gas.

[0028] A liquid inlet 7 is provided on the surface of the high-pressure compressor 8. The oil and gas collected by the oil collector 9 in the high-pressure compressor 8 can be extracted through the liquid inlet 7 (see details below). This allows a small amount of oil and gas that comes to the high-pressure compressor 8 with Freon to flow back to the refrigeration unit, preventing Freon from carrying the oil and gas to the subsequent evaporator, clogging the evaporator, affecting the heat exchange effect of the system, and causing the entire industrial system to fail to reach the design operating conditions.

[0029] The above is the basic structure of this utility model. The following will describe the specific embodiments of this utility model.

[0030] In a preferred embodiment, in order to ensure the smooth operation of the low-pressure compressor 1 and the high-pressure compressor 8, and to store the collected oil.

[0031] The low-pressure compressor 1 also includes a low-pressure compressor oil tank 3, which is located at the bottom of the low-pressure compressor 1 and connected to all the filter screens 2. It receives and stores the oil collected from the filter screens 2.

[0032] The high-pressure compressor 8 also includes a high-pressure compressor oil tank 6, which is located at the bottom of the high-pressure compressor 8 and connected to both an oil collector 9 and a liquid extraction port 7. The oil tank 6 receives and stores the oil separated in the secondary process and extracts it through the liquid extraction port 7, as described above. Therefore, this device ensures that the refrigeration unit does not lack oil and the evaporator does not accumulate oil.

[0033] To further facilitate the extraction of oil from the low-pressure oil tank 3 and the high-pressure oil tank 6, the device also includes:

[0034] The oil tank balance pipe 5 is connected to the low-pressure oil tank 3 and the high-pressure oil tank 6 respectively, so that the low-pressure oil tank 3 and the high-pressure oil tank 6 maintain the same pressure. When the oil in the high-pressure oil tank 6 is extracted through the liquid extraction port 7, the oil in the low-pressure oil tank 3 can be extracted at the same time because the low-pressure oil tank 3 and the high-pressure oil tank 6 maintain the same pressure.

[0035] In a preferred embodiment, since the pressure difference between the low-pressure compressor 1 and the high-pressure compressor 8 during operation may lead to dangerous operation of the entire oil return device, the device further includes: a first balancing pipe 10, connected to both the low-pressure compressor 1 and the high-pressure compressor 8, to ensure real-time pressure balance during operation; and a second balancing pipe 11, connected to both the high-pressure compressor 8 and the inlet pipe 4, to balance the pressure between the high-pressure compressor 8 and the inlet pipe 4. This achieves pressure balance among the low-pressure compressor 1, the high-pressure compressor 8, and the inlet pipe 4, ensuring the safe operation of the entire device.

[0036] Based on the pressure balance, both the first balancing pipe 10 and the second balancing pipe 11 are equipped with several pressure valves. The pressure valves can automatically open when the internal pressure is too high, so as to ensure the safety of the device operation without affecting the device's operating efficiency.

[0037] In addition, the device also includes:

[0038] The drive unit 12 is connected to the low-voltage generator 1 and the high-voltage generator 8 respectively, providing drive for the low-voltage generator 1 and the high-voltage generator 8. Figure 1 As shown, its position is generally set in the middle part, in the lower part between the low-pressure unit 1 and the high-pressure unit 8. In this way, the overall layout of the device is not affected, and the corresponding installation is achieved.

[0039] Based on the above description, the oil-gas mixture enters the low-pressure compressor 1 through the inlet pipe 4. It passes through the filter screen 2 of the low-pressure compressor 1, achieving initial oil-gas separation. The oil-gas is collected in the low-pressure compressor oil tank 3. The high-pressure compressor 8 receives the initially separated liquid and performs secondary separation through its oil collector 9. The separated oil-gas is collected in the high-pressure compressor oil tank 6 and extracted through the liquid outlet 7, ensuring that the refrigeration unit does not lack oil and the evaporator does not accumulate oil. Furthermore, this invention employs a first balance pipe 10 and a second balance pipe 11, further enhancing the overall safety of the entire device. This invention returns any unseparated oil-gas to the oil collector 9 and then pressurizes it back into the unit, thus achieving a 60% reduction in oil leakage compared to the previous method.

[0040] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above content. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. An oil return device for a centrifugal chiller, characterized in that, One end of the device is connected to the inlet pipe (4), and the other end is connected to the evaporator. The device receives the oil-gas mixture from the inlet pipe (4) and separates it. The device includes: The low-pressure unit (1) is connected to the inlet pipe (4) to receive the oil-gas mixture and perform preliminary separation on it; The high-pressure unit (8) is connected to the low-pressure unit (1) and the evaporator respectively, and receives the liquid after preliminary separation and performs secondary separation on it; The low-pressure unit (1) includes at least one filter screen (2) disposed at the connection between the low-pressure unit (1) and the high-pressure unit (8) for preliminary separation of liquid; The high-pressure generator (8) includes: The oil collector (9) performs secondary separation on the liquid after the initial separation; A liquid extraction port (7) is provided on the surface of the high-pressure machine (8). The liquid extraction port (7) extracts the oil and gas collected by the oil collector (9) in the high-pressure machine (8).

2. The oil return device for a centrifugal chiller according to claim 1, characterized in that, The low-pressure compressor (1) further includes a low-pressure compressor oil tank (3), which is located at the bottom of the low-pressure compressor (1), connected to all filters (2), receiving and storing the oil collected from the filters (2).

3. The oil return device for a centrifugal chiller according to claim 2, characterized in that, The high-pressure machine (8) also includes a high-pressure machine oil tank (6), which is located at the bottom of the high-pressure machine (8) and is connected to the oil collector (9) and the liquid outlet (7) respectively to receive the oil separated in the second stage and store it.

4. The oil return device for a centrifugal chiller according to claim 3, characterized in that, The device also includes an oil tank balance pipe (5), which is connected to the low-pressure oil tank (3) and the high-pressure oil tank (6) respectively, so that the low-pressure oil tank (3) and the high-pressure oil tank (6) maintain the same pressure inside.

5. The oil return device for a centrifugal chiller according to claim 4, characterized in that, The device further includes a first balancing pipe (10), which is connected to the low-pressure unit (1) and the high-pressure unit (8) respectively, and balances their internal pressure in real time.

6. The oil return device for a centrifugal chiller according to claim 5, characterized in that, The second balancing pipe (11) is connected to the high-pressure machine (8) and the inlet pipe (4) respectively, so that the pressure of the low-pressure machine (1), the high-pressure machine (8) and the inlet pipe (4) are balanced.

7. The oil return device for a centrifugal chiller according to claim 6, characterized in that, Both the first balance tube (10) and the second balance tube (11) are equipped with several pressure valves, which can automatically open when the internal pressure is too high.

8. The oil return device for a centrifugal chiller according to claim 7, characterized in that, The device further includes a drive unit (12) connected to the low-pressure unit (1) and the high-pressure unit (8) respectively, providing drive for the low-pressure unit (1) and the high-pressure unit (8).

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