Compressor cold oil system, compressor and refrigeration equipment

Abstract

The present invention discloses a compressor cold oil system, a compressor, and a refrigeration device. The compressor cold oil system includes: at least one oil return chamber, a motor cooling flow channel opened on the housing of the compressor, a pre-cooling pipe disposed in the oil return chamber, a pre-cooling diversion branch that diverts the refrigerant flowing out of the motor cooling flow channel to the pre-cooling pipe, and a heat exchange device connected to the pre-cooling pipe and the oil return chamber. The refrigerant flowing out of the pre-cooling pipe and the lubricating oil flowing out of the oil return chamber exchange heat in the heat exchange device. The pre-cooling diversion branch is opened on the housing of the compressor. The motor cooling flow channel is further connected with a cooling diversion branch that diverts the refrigerant to the heat exchange device. The refrigerant flowing out of the cooling diversion branch converges with the refrigerant flowing out of the pre-cooling pipe in the heat exchange device. The present invention can simplify the external pipeline structure of the compressor, optimize the seismic performance of the compressor, fully cool the lubricating oil, fully vaporize the refrigerant, prevent liquid carry-over during compressor suction, and improve the energy efficiency of the compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and particularly to a compressor cold oil system, a compressor, and a refrigeration device. Background Art

[0002] When a compressor is operating, under high-speed conditions, the bearing uses the high-pressure oil film generated by the significant dynamic pressure effect to support the rotating body. Since the lubricating oil has viscosity, the oil film consumes mechanical work and generates heat during the movement process. Especially under high-speed and heavy-load conditions, the temperature of the oil film will rise to form a non-uniformly distributed temperature field, and the increase in temperature will cause the viscosity of the lubricating oil to decrease, resulting in a non-uniformly distributed viscosity field of the oil film. Moreover, the change in temperature will also bring a series of problems such as bearing deformation, affecting the operating characteristics of the entire shafting. It can be seen that controlling the temperature of the lubricating oil is a key factor to ensure the normal operation of the compressor.

[0003] The prior art generally arranges an external heat exchanger on the external pipeline of the compressor to cool the lubricating oil used in the compressor. The lubricating oil is led out to the external heat exchanger for heat exchange. Existing external heat exchangers have structures such as air-cooled and water-cooled types. Not only are the structures complex, there are many suspended pipelines outside the compressor, affecting its seismic performance during transportation and operation, but also the cooling capacity of the plate heat exchanger is limited by volume, and the physical properties of the lubricating oil are greatly affected by temperature. If the lubricating oil cannot be fully cooled, the increase in oil temperature will cause bearing failure.

[0004] In addition, the existing compressor structure usually opens a spiral flow channel on the compressor housing. After the refrigerant cools the motor through the spiral flow channel on the compressor housing, it directly returns to the flash tank from the gas return port at the bottom of the cylinder body. At this time, the refrigerant is not fully utilized, the refrigerant temperature is relatively low and the gasification is not sufficient, and the return of more liquid refrigerant to the compressor intake port easily causes liquid carry-over during suction, affecting the energy efficiency of the compressor. Summary of the Invention

[0005] In order to solve the problems of complex external pipelines of the existing compressor and insufficient gasification of the refrigerant for cooling the motor, the present invention provides a compressor cold oil system, a compressor, and a refrigeration device. This compressor cold oil system can not only simplify the external pipeline structure of the compressor and optimize the seismic performance of the compressor, but also fully cool the lubricating oil and fully gasify the refrigerant, improving the energy efficiency of the compressor.

[0006] The technical solution adopted by the present invention is to design a compressor cold oil system, including: at least one oil return cavity, a motor cooling flow channel opened on the housing of the compressor, a pre-cooling pipe arranged in the oil return cavity, and a pre-cooling diversion branch that leads the refrigerant flowing out of the motor cooling flow channel to the pre-cooling pipe, and the pre-cooling diversion branch is opened on the compressor housing.

[0007] Further, the pre-cooling pipe is located at the bottom of the oil return cavity where it is located, and the pre-cooling pipe is immersed in the lubricating oil of the oil return cavity.

[0008] Further, the shape of the pre-cooling pipe in the oil return cavity is spiral, which increases the contact area between the pre-cooling pipe and the lubricating oil and improves the heat exchange efficiency.

[0009] Further, each oil return cavity is separately provided with a pre-cooling pipe and a pre-cooling diversion branch, and the ratio of the flow channel cross-sectional areas of different pre-cooling diversion branches is the same as the ratio of the bearing heat generation of the corresponding oil return cavity.

[0010] Further, the compressor cold oil system further includes: a heat exchange device connected to the pre-cooling pipe and the oil return cavity, and the refrigerant flowing out of the pre-cooling pipe and the lubricating oil flowing out of the oil return cavity exchange heat in the heat exchange device.

[0011] Further, the motor cooling flow channel is further connected with a cooling diversion branch for guiding the refrigerant to the heat exchange device, and the refrigerant flowing out of the cooling diversion branch converges with the refrigerant flowing out of the pre-cooling pipe in the heat exchange device.

[0012] Further, a control valve for adjusting the refrigerant flow rate is installed in the cooling diversion branch and / or the pre-cooling diversion branch.

[0013] Further, the compressor cold oil system further includes: a temperature sensor connected to the control valve, and the temperature sensor detects the temperature of the lubricating oil flowing out of the heat exchange device or the temperature of the lubricating oil in the compressor oil tank; the control valve increases the opening degree when the lubricating oil temperature is higher than the set temperature, and the control valve decreases the opening degree when the lubricating oil temperature is lower than the set temperature.

[0014] In some embodiments, the heat exchange device includes: a housing, a partition that divides the inner cavity of the housing into a lubricating oil cavity and a refrigerant cavity, and rib plates that are arranged at intervals in the refrigerant cavity to form a refrigerant flow channel.

[0015] Further, the refrigerant cavity surrounds the lubricating oil cavity, and the refrigerant flow channel spirally surrounds the lubricating oil cavity.

[0016] The present invention also provides a compressor, including: a housing having at least one oil return cavity, a motor installed inside the housing, and a motor cooling flow channel opened on the housing, and this compressor adopts the above compressor cold oil system.

[0017] Further, the compressor is a centrifugal compressor, the centrifugal compressor has two oil return cavities, which are the first bearing oil return cavity and the second bearing oil return cavity provided at both ends of the motor respectively, the housing includes a housing body, a box body, a cylinder body and an end cover connected in sequence, the housing body is provided with a compression cavity, the box body is provided with the first bearing oil return cavity, the motor cooling flow channel is opened on the cylinder body, and the end cover is provided with the second bearing oil return cavity.

[0018] The present invention also provides a refrigeration device, including: a compressor, and this compressor adopts the above compressor, and the refrigeration device can be an air conditioner or a refrigerator.

[0019] Compared with the prior art, a pre-cooling pipe is arranged in the oil return cavity of the compressor of the present invention, and the refrigerant in the motor cooling flow path is led into the pre-cooling pipe. The lubricating oil is pre-cooled through the preset cooling pipe inside the oil return cavity, reducing complex and redundant external pipelines, optimizing the seismic performance of the compressor. At the same time, the heat exchange amount between the lubricating oil and the refrigerant in the heat exchange device outside the compressor is reduced, which is beneficial to reducing the volume of the heat exchange device. Moreover, the heat of the lubricating oil can be used to fully vaporize the refrigerant, preventing the compressor from sucking liquid and improving the energy efficiency of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be described in detail below with reference to the embodiments and the drawings, wherein:

[0021] Figure 1 is a simplified schematic diagram of the compressor of the present invention;

[0022] Figure 2 is a structural schematic diagram of the compressor of the present invention;

[0023] Figure 3 is a schematic diagram of the principle of the cold oil system of the compressor of the present invention;

[0024] Figure 4 is a structural schematic diagram of the heat exchange device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the drawings and the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] As Figure 1 、 2 shown, the cold oil system of the compressor proposed by the present invention is applicable to the cooling of the lubricating oil of the compressor, especially the centrifugal compressor. The compressor 1 generally has a housing 10, a motor 11 and an oil tank, etc. The housing 10 is provided with a compression chamber 12 and at least one oil return cavity 13. The motor 11 is installed in the housing 10, and the motor 11 provides power for the refrigeration cycle circuit where the compressor 1 is located. The main shaft 111 of the motor 11 is supported by bearings. The lubricating oil in the oil tank is pumped to the bearings for lubrication, and the lubricating oil flowing down from the bearings flows into the oil return cavity 13 and is sent back to the oil tank after being cooled. A motor cooling flow path 14 for cooling the motor 11 is opened on the housing. The low-temperature refrigerant in the refrigeration cycle where the compressor 1 is located is sent back to the suction port after passing through the motor cooling flow path 14. The motor cooling flow path 14 can be connected to the outlet end of the evaporator or the outlet end of the condenser, and its connection method can be designed according to actual needs, and the present invention does not limit this.

[0027] As Figure 3As shown in the figure, the compressor's cold oil system includes: an oil return chamber 13, a motor cooling flow channel 14, a pre-cooling pipe 15, and a pre-cooling diversion branch 16. The pre-cooling pipe 15 is arranged inside the oil return chamber 13. The pre-cooling diversion branch 16 connects the outlet of the motor cooling flow channel 14 and the inlet of the pre-cooling pipe 15, and diverts the refrigerant flowing out of the motor cooling flow channel 14 to the pre-cooling pipe 15 through the pre-cooling diversion branch 16. When the refrigerant passes through the pre-cooling pipe 15, it absorbs the heat of the lubricating oil and vaporizes while the lubricating oil is preliminarily cooled in the oil return chamber 13, reducing the heat exchange amount between the lubricating oil and the refrigerant in the heat exchange device 2 outside the compressor 1, which is beneficial to reducing the volume of the heat exchange device 2. To improve the cooling effect of the pre-cooling pipe 15, the pre-cooling pipe 15 is located at the bottom of the oil return chamber 13 where it is located, so that the pre-cooling pipe 15 is immersed in the lubricating oil. The shape of the pre-cooling pipe 15 in the oil return chamber 13 is spiral. Using a spiral thin pipe can increase the heat exchange area between the refrigerant and the lubricating oil.

[0028] In a preferred embodiment, each oil return chamber 13 is separately provided with a pre-cooling pipe 15 and a pre-cooling diversion branch 16. Since the cross-sectional area of the flow channel of the pre-cooling diversion branch 16 determines the refrigerant flow rate entering its corresponding oil return chamber 13, and the more heat-generating bearings require more refrigerant, the ratio of the cross-sectional areas of the flow channels of different pre-cooling diversion branches 16 is the same as the ratio of the bearing heat generation amounts of their corresponding oil return chambers 13. At the same time, the pre-cooling diversion branch 16 is opened on the housing 10 of the compressor 1, which is achieved by drilling holes in the housing 10. Both the pre-cooling pipe 15 and the pre-cooling diversion branch 16 are arranged inside the housing 10 of the compressor 1, which can reduce the heat exchange pipelines suspended outside the compressor 1 and improve the appearance aesthetics and seismic performance of the compressor 1.

[0029] As Figure 3 、 4 shown in the figure, the compressor's cold oil system further includes: a heat exchange device 2 installed outside the compressor 1. The heat exchange device 2 is connected to the oil return chamber 13 and the pre-cooling pipe 15 respectively through pipelines. The refrigerant flowing out of the pre-cooling pipe 15 and the lubricating oil flowing out of the oil return chamber 13 exchange heat in the heat exchange device 2, and the lubricating oil is further cooled. In practical applications, the pipeline connecting the pre-cooling pipe 15 and the heat exchange device 2 can be separately provided or integrally designed on the pre-cooling pipe 15. To improve the heat exchange efficiency, the outlet of the motor cooling flow channel 14 is also connected with a cooling diversion branch 17 that diverts the refrigerant to the heat exchange device 2. The refrigerant flowing out of the cooling diversion branch 17 converges with the refrigerant flowing out of the pre-cooling pipe 15 in the heat exchange device 2, and the lubricating oil flowing out of all the oil return chambers 13 converges in the heat exchange device 2.

[0030] A control valve 18 is installed in the cooling drainage branch 17 or the pre-cooling drainage branch 16 to regulate the refrigerant flow rate of the branch where it is located. In practical applications, control valves can also be installed in both the cooling drainage branch 17 and the pre-cooling drainage branch 16 at the same time. The compressor cold oil system is provided with a temperature sensor connected to the control valve 18, and the temperature sensor detects the temperature of the lubricating oil flowing out of the heat exchange device 2 or the temperature of the lubricating oil in the oil tank.

[0031] When the compressor load is small, the heat generated by the bearings and the motor is less. Excessive cold supply will cause the lubricating oil temperature to be too low, and the increase in lubricating oil viscosity will lead to an increase in bearing energy consumption. Therefore, the control valve 18 reduces the opening degree when the lubricating oil temperature is lower than the set temperature to reduce the cold supply. When the compressor load is large, the heat generated by the bearings and the motor is more. Insufficient cold supply will cause the lubricating oil temperature to be too high, and the high temperature of the lubricating oil will cause the bearing to fail. Therefore, the control valve 18 increases the opening degree when the lubricating oil temperature is higher than the set temperature to increase the cold supply.

[0032] It should be noted that when the compressor 1 is working, the temperature sensor continuously detects the lubricating oil temperature in real time, and the control valve 18 continuously adjusts dynamically according to the comparison result between the lubricating oil temperature and the set temperature, so as to keep the lubricating oil temperature basically constant, improve the bearing life and working stability, and enhance the energy efficiency of the compressor.

[0033] As Figure 4 shown, the specific structure of the heat exchange device 2 is as follows. The heat exchange device 2 includes: a housing 21, a partition 22, and a rib plate 23. The partition 22 divides the inner cavity of the housing 21 into an independent lubricating oil cavity 211 and a refrigerant cavity 212. The rib plates 23 are arranged at intervals in the refrigerant cavity 212 to form a refrigerant flow channel. The refrigerant flowing out of the cooling drainage branch 17 and the refrigerant flowing out of the pre-cooling pipe 15 converge in the refrigerant flow channel, and the lubricating oil flowing out of all the oil return cavities 13 converges in the lubricating oil cavity. The refrigerant cavity 212 surrounds the lubricating oil cavity 211 externally, and the refrigerant flow channel spirally surrounds the lubricating oil cavity 211. The spiral refrigerant flow channel can increase the heat exchange area on the one hand, and on the other hand, it can increase the flow channel length of the refrigerant passing through the heat exchange device 2, extend the heat exchange time, and effectively improve the heat exchange efficiency.

[0034] As Figure 1 、 2As shown, for a centrifugal compressor, the main shaft 111 of the motor 11 is supported by a compound bearing 112 and a motor bearing 113 arranged at intervals. The compound bearing 112 is located at one end of the main shaft 111 close to the compression chamber 12, and the motor bearing 113 is located at the other end of the main shaft 111 away from the compression chamber 12. The compressor 1 has two oil return chambers 13, namely a first bearing oil return chamber 13A and a second bearing oil return chamber 13B. The first bearing oil return chamber 13A is located below the compound bearing 112, and the lubricating oil flowing down from the compound bearing 112 falls into the first bearing oil return chamber 13A. The second bearing oil return chamber 13B is located below the motor bearing 113, and the lubricating oil left by the motor bearing 113 falls into the second bearing oil return chamber 13B.

[0035] As Figure 3 shown, the first bearing oil return chamber 13A is provided with a first pre-cooling pipe 15A, and the second bearing oil return chamber 13B is provided with a second pre-cooling pipe 15B. Two pre-cooling diversion branches 16 corresponding to the pre-cooling pipes 15 are opened on the housing 10. The two pre-cooling diversion branches 16 are a first pre-cooling diversion branch 16A and a second pre-cooling diversion branch 16B respectively. The ratio of the flow channel cross-sectional areas of the two pre-cooling diversion branches 16 is the same as the ratio of the bearing heat generation amounts of the corresponding oil return chambers 13. The refrigerant flowing out of the motor cooling flow channel 14 flows to the heat exchange device 2 in three paths. The cooling diversion branch 17 diverts a part of the refrigerant flowing out of the motor cooling flow channel 14 to the heat exchange device 2. The first pre-cooling diversion branch 16A diverts a part of the refrigerant flowing out of the motor cooling flow channel 14 to the first pre-cooling pipe 15A, and the refrigerant flows through the first pre-cooling pipe 15A to the heat exchange device 2. The second pre-cooling diversion branch 16B diverts a part of the refrigerant flowing out of the motor cooling flow channel 14 to the second pre-cooling pipe 15B, and the refrigerant flows through the second pre-cooling pipe 15B to the heat exchange device 2.

[0036] As Figure 1 、 2 shown, in some embodiments, the housing 10 includes a housing 101, a box body 102, a cylinder body 103 and an end cover 104 connected in sequence. The housing 101 is provided with a compression chamber 12, the box body 102 is provided with a first bearing oil return chamber 13A, the motor cooling flow channel 14 and the pre-cooling diversion branch 16 are opened on the cylinder body 103, and the end cover 104 is provided with a second bearing oil return chamber 13B.

[0037] The present invention also provides a refrigeration device, including: a compressor, which adopts the above compressor, and the refrigeration device can be an air conditioner or a refrigerator.

[0038] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Compressor cold oil system, comprising: At least one oil return cavity and a motor cooling flow channel opened on the housing of the compressor. The low-temperature refrigerant in the refrigeration cycle where the compressor is located is sent back to the suction port after passing through the motor cooling flow channel. It is characterized in that the compressor cold oil system further includes: a pre-cooling pipe arranged in the oil return cavity, a pre-cooling diversion branch for guiding the refrigerant flowing out of the motor cooling flow channel to the pre-cooling pipe, and a heat exchange device connected to the pre-cooling pipe and the oil return cavity. The refrigerant flowing out of the pre-cooling pipe and the lubricating oil flowing out of the oil return cavity exchange heat in the heat exchange device; The motor cooling flow channel is further connected with a cooling diversion branch for guiding the refrigerant to the heat exchange device, and the refrigerant flowing out of the cooling diversion branch converges with the refrigerant flowing out of the pre-cooling pipe in the heat exchange device.

2. The compressor cold oil system according to claim 1, characterized in that, The pre-cooling diversion branch is opened on the housing of the compressor.

3. The compressor cold oil system according to claim 1, characterized in that, The pre-cooling pipe is located at the bottom of the oil return cavity where it is located.

4. The compressor cold oil system according to claim 1, wherein, The shape of the pre-cooling pipe in the oil return cavity is spiral.

5. The compressor cold oil system according to claim 1, wherein Each oil return cavity is separately provided with the pre-cooling pipe and the pre-cooling diversion branch, and the ratio of the flow channel cross-sectional areas of different pre-cooling diversion branches is the same as the ratio of the bearing heat generation amounts of the corresponding oil return cavities.

6. The compressor cold oil system according to claim 1, wherein, A control valve for adjusting the refrigerant flow rate is installed on the cooling diversion branch and / or the pre-cooling diversion branch.

7. The compressor cold oil system according to claim 6, characterized in that, It further includes: A temperature sensor connected to the control valve. The temperature sensor detects the temperature of the lubricating oil flowing out of the heat exchange device or the temperature of the lubricating oil in the compressor oil tank. The control valve increases the opening degree when the lubricating oil temperature is higher than the set temperature, and the control valve decreases the opening degree when the lubricating oil temperature is lower than the set temperature.

8. The compressor cold oil system according to claim 1, wherein, The heat exchange device includes: a housing, a partition for separating the inner cavity of the housing into a lubricating oil cavity and a refrigerant cavity, and rib plates arranged at intervals in the refrigerant cavity to form a refrigerant flow channel.

9. The compressor cold oil system according to claim 8, characterized in that, The refrigerant cavity surrounds the outside of the lubricating oil cavity, and the refrigerant flow channel spirally surrounds the lubricating oil cavity.

10. Compressor, comprising: A housing having at least one oil return cavity, a motor installed inside the housing, and a motor cooling flow channel opened on the housing. It is characterized in that the compressor adopts the compressor cold oil system according to any one of claims 1 to 9.

11. The compressor according to claim 10, wherein, The compressor is a centrifugal compressor, and the centrifugal compressor has two oil return cavities, namely a first bearing oil return cavity and a second bearing oil return cavity provided at both ends of the motor.

12. The compressor according to claim 11, characterized in that, The housing includes a housing body, a box body, a cylinder body and an end cover connected in sequence. The housing body is provided with a compression cavity, the box body is provided with a first bearing oil return cavity, the motor cooling flow channel is opened on the cylinder body, and the end cover is provided with a second bearing oil return cavity.

13. Refrigeration equipment, comprising: A compressor, characterized in that the compressor adopts the compressor according to any one of claims 10 to 12.

14. The refrigeration device according to claim 13, wherein, The refrigeration equipment is an air conditioner or a refrigerator.

Images