Variable-frequency helium compressor with electric control cooling circulation system

Abstract

The invention discloses a variable-frequency helium compressor with an electric control cooling circulation system. The variable-frequency helium compressor is mainly composed of a helium compressor, an electric control unit and the electric control cooling circulation system. According to the system, high-temperature lubricating oil discharged from the oil discharge outlet of the vortex pressing bag enters the water-cooling heat exchanger, and the high-temperature lubricating oil exchanges heat with cold water introduced from the outside to achieve the purpose of cooling; impurities of the cooled lubricating oil are filtered through the first filter, then the cooled lubricating oil is throttled and depressurized through the first throttling device and then enters the cooling plate to cool the electric control unit, an outlet of the cooling plate is connected to an oil return opening of the vortex pressing bag, the cooled lubricating oil returns to the vortex pressing bag again, and the whole cooling circulation process is completed. Efficient heat dissipation of the electric control unit is achieved through an oil return system of the helium compressor, only one small cooling plate needs to be additionally arranged, and the whole machine integration degree and the space utilization rate are improved; the temperature of lubricating oil flowing through the electric control unit is usually about 30-50 DEG C, so that the condensation phenomenon is effectively prevented, and electrical elements such as a circuit board and a frequency converter are protected from being influenced.

Description

Technical Field

[0001] This invention relates to the field of helium compressors, and more particularly to a variable frequency helium compressor with an electronically controlled cooling cycle system. Background Technology

[0002] In numerous industrial and commercial applications of cryogenics, particularly in the field of cryogenic physics research instruments, the installation space for cryogenic equipment is extremely limited, leading to a growing demand for lightweight and portable designs. In variable frequency helium compressor systems, inverters are required to regulate the compressor's speed. However, inverters generate significant heat. To ensure that the electrical components in the control unit can operate continuously and efficiently within their optimal temperature range, effective heat dissipation and temperature control measures must be implemented. Currently, the commonly used heat dissipation methods require the installation of fins and fans, as well as the design and installation of air vents within the overall unit. This method occupies a large space, has uneven cooling effects, and is highly sensitive to ambient temperature. Furthermore, the fans increase the overall energy consumption of the unit. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a variable frequency helium compressor with an electronically controlled cooling circulation system. It utilizes the ambient temperature lubricating oil in the compressor's oil return system to cool the compressor's electronic control unit, resulting in high space utilization.

[0004] Technical solution: The present invention discloses a variable frequency helium compressor with an electronically controlled cooling circulation system, comprising a helium compressor with a scroll compressor, an electronic control unit, and an electronically controlled cooling circulation system for dissipating heat from the electronic control unit. The system cools the high-temperature lubricating oil discharged from the oil outlet of the scroll compressor via a water-cooled heat exchanger, and then flows through a cooling plate to cool the electronic control unit. The outlet of the cooling plate is connected to the oil return port of the scroll compressor.

[0005] Furthermore, a first filter for filtering impurities in the lubricating oil and a first throttling device for reducing the pressure of the lubricating oil in the pipeline are sequentially connected between the water-cooled heat exchanger and the cooling plate. The lubricating oil, after being throttled and depressurized by the first throttling device, enters the cooling plate at a temperature higher than the dew point temperature of the working environment.

[0006] Preferably, the electronically controlled cooling circulation system also includes a first temperature sensor located at the inlet of the cooling plate, used to detect the temperature of the lubricating oil entering the cooling plate, and to regulate the temperature of the lubricating oil in the cooling plate by adjusting the inlet water flow and temperature of the water-cooled heat exchanger.

[0007] Furthermore, a three-way diverter valve is added at the outlet of the first throttling device. One end of the three-way diverter valve is connected to the inlet pipe of the cooling plate, and the other end is connected to the outlet pipe of the cooling plate. A second temperature sensor is installed on the housing of the electronic control unit to monitor the housing temperature of the electronic control unit and adjust the opening of the three-way diverter valve at any time to control the amount of lubricating oil entering the cooling plate, so as to ensure that the electronic control unit always operates within the optimal temperature range.

[0008] Furthermore, the water-cooled heat exchanger also cools the high-temperature helium gas discharged from the vortex compressor. The high-temperature helium gas at the exhaust port is cooled by the water-cooled heat exchanger and then enters the oil-gas separator for separation.

[0009] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0010] (1) The cooling cycle of the electronic control unit is realized by using the oil return system of the helium compressor. Based on the helium compressor system, only a small cooling plate is added, which improves the integration of the whole machine and the space utilization rate, and also reduces energy consumption.

[0011] (2) Use lubricating oil to cool the electronic control unit. Lubricating oil has good thermal conductivity but slow temperature rise and good "heat storage" capacity. The oil temperature after throttling and pressure reduction is usually 30℃~50℃, which is within the normal temperature range. Using normal temperature lubricating oil to cool the electronic control unit can effectively prevent condensation and protect the circuit board and frequency converter and other electrical components from the effects of condensation.

[0012] (3) The temperature sensor detects the temperature of the lubricating oil after throttling and pressure reduction in the return oil system. Using an external chiller, the inlet water flow and temperature of the water-cooled heat exchanger are adjusted. While ensuring the stable operation of the compressor, the temperature of the lubricating oil in the cooling plate is precisely controlled to cool and control the temperature of the electrical control unit, so that the electrical components of the compressor can work continuously and efficiently within the optimal temperature range. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0014] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention. Detailed Implementation

[0015] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0016] Example 1

[0017] like Figure 1As shown, this embodiment provides a variable frequency helium compressor with an electronically controlled cooling circulation system. The GM refrigeration unit's cold head 11 utilizes high-pressure helium from the compressor outlet to provide cooling, and returns ambient-temperature, low-pressure helium to the compressor 2. The electronically controlled cooling circulation system includes a water-cooled heat exchanger 4, a first filter 6, a first throttling device 7, a cooling plate 5, a first temperature sensor 8, and an electronic control unit 3. The scroll compressor 1 can be a vertical or horizontal compressor. High-temperature lubricating oil discharged from the scroll compressor 1's drain port 101 is heated by the water-cooled heat exchanger 4, then filtered by the first filter 6 to remove impurities. The oil pressure is then regulated by the first throttling device 7 before entering the cooling plate 5 to cool the electronic control unit 3. Ambient-temperature, low-pressure lubricating oil re-enters the scroll compressor 1 through the oil return port 102, utilizing the helium compressor's oil return system to cool the electronic control unit. The electronic control unit 3 is used to precisely control the various components of the helium compressor. In order to effectively cool the electronic control unit 3, the first temperature sensor 8 at the inlet of the cooling plate 5 detects the temperature of the lubricating oil in the oil return system. The external chiller unit is used to adjust the inlet water flow and temperature of the water-cooled heat exchanger to precisely control the temperature of the lubricating oil entering the cooling plate, thereby cooling and controlling the temperature of the electronic control unit 3.

[0018] The water-cooled heat exchanger 4 uses chilled water supplied by an external chiller to cool the high-temperature helium and lubricating oil at the outlet of the pressure tank. The vortex pressure tank 1 compresses the helium and lubricating oil working fluid at the inlet and outlet to high pressure. The helium separates under gravity and is discharged from the exhaust port 103. The high-temperature helium is cooled by the water-cooled heat exchanger 4 and then enters the oil-gas separator 21 for further separation. Cooling water enters the water-cooled heat exchanger from the inlet pipe 12 and then flows out through the outlet pipe 13. When the first temperature sensor detects that the lubricating oil temperature is too high, the chiller inlet water flow rate can be increased or the chiller inlet water temperature can be decreased to reduce the lubricating oil temperature entering the cooling plate. When the lubricating oil temperature is detected as too low, the chiller inlet water flow rate can be decreased or the chiller inlet water temperature can be increased to increase the lubricating oil temperature entering the cooling plate. The water-cooled heat exchanger 4 can be a shell-and-tube heat exchanger or a plate heat exchanger. When a shell-and-tube heat exchanger is selected, it can be placed on the adsorber 14 to effectively improve the overall integration of the unit.

[0019] After heat exchange in the water-cooled heat exchanger, the ambient temperature lubricating oil, after being throttled and depressurized by the first throttling device 7, enters the cooling plate 5 at a temperature close to ambient temperature, typically between 30℃ and 50℃, which is higher than the dew point temperature of the working environment. The lubricating oil has a high specific heat capacity and a slow temperature rise. The heat exchange temperature of the lubricating oil ensures that the compressor's electronic control unit 3 is cooled to its optimal operating temperature range, effectively preventing condensation on the electronic control unit. This allows the helium compressor to operate without being constrained by ambient temperature, eliminating the need for special sealing or dehumidification treatment of the electronic control unit and improving the unit's safety. Furthermore, the lubricating oil has strong thermal conductivity, good cooling effect, and a high specific heat capacity. Its temperature rise after being heated by the electronic control unit is small, having no impact on the scroll compressor 1, allowing it to resume operation.

[0020] Figure 1 The detailed settings of other components in this embodiment are shown. In practical applications, they can be modified as needed. Figure 1 The helium circulation system is as follows: One end of the cold head outlet of the GM refrigerator is connected to the inlet pipe. Low-pressure helium enters the helium compressor system through the make-up pipe 22 and the inlet pipe 23. The make-up pipe and the inlet pipe are connected to one end of the buffer tank 15, and the first pressure sensor 24 is on the inlet pipe. The other end of the buffer tank 15 is connected to the inlet 104 of the scroll compressor 1. Room temperature helium mixes with ambient temperature lubricating oil in this section. The room temperature low-pressure oil-gas mixture is compressed in the scroll plate of the scroll compressor. After the high temperature and high pressure helium separates under gravity, it is discharged from the exhaust port 103. The other end of the exhaust port is connected to the water-cooled heat exchanger. One end of the heat exchanger 4 is connected to the water-cooled heat exchanger, and the other end is connected to one end of the oil-gas separator 21. The other end of the oil-gas separator 21 is connected to one end of the check valve 25, the solenoid valve 26, and the adsorber 14. The other end of the check valve 25 is connected to the inlet of the buffer tank to bypass helium. The other end of the solenoid valve 26 is connected to the second throttling device 28 to balance the compressor's shutdown pressure. The other end of the second throttling device is connected to the inlet of the buffer tank 15. The other end of the adsorber 14 is connected to the exhaust pipe 29. The other end of the exhaust pipe is connected to the inlet of the GM refrigerator's cold head, thus forming a helium circulation system. A third temperature sensor and a fourth temperature sensor are respectively installed on the inlet pipe 12 and the outlet pipe 13 of the water-cooled heat exchanger. A safety valve 27 is installed on the oil-gas separator to prevent excessive pressure.

[0021] Figure 1The lubricating oil circulation system is as follows: the room temperature high-pressure lubricating oil separated by the oil-gas separator 21 enters one end of the second filter 30 to filter impurities; the other end of the second filter 30 is connected to one end of the third throttling device 31 to throttle and reduce pressure; the other end of the third throttling device 31 is connected to one end of the outlet of the buffer tank 15 and flows into the helium circulation system; the room temperature lubricating oil cooled by the water-cooled heat exchanger 4 enters one end of the first filter 6; the other end of the first filter is connected to one end of the first throttling device 7; the other end of the first throttling device 7 is connected to one end of the cooling plate 5; the other end of the cooling plate 5 is connected to the oil return port 102; after being pressurized by the scroll plate, the lubricating oil undergoes oil-gas separation under gravity and passes downward through the gap between the motor rotor and the motor stator coils and the gap between the motor stator silicon steel sheet and the scroll pressure tank housing, finally depositing at the bottom of the scroll pressure tank 1 to form a relatively stable oil surface. During the process of the motor passing through the scroll pressure tank 1, the lubricating oil can absorb some of the heat of the motor and play a role in cooling the motor. The lubricating oil deposited at the bottom of the vortex pressure tank 1 is drawn in through the oil suction port 106 of the lower rotating shaft 105 and flows upward along the upper rotating shaft 107 to lubricate the rotating mechanism of the vortex disk. The lubricating oil deposited at the bottom of the vortex pressure tank 1 is led out of the vortex pressure tank through one end of the oil discharge port 101, and the other end of the oil discharge port is sequentially connected to the oil replenishment port 32 and one end of the water-cooled heat exchanger 4 to form a lubricating oil circulation system.

[0022] Taking an ambient temperature of 30℃ and a relative humidity of 80% as an example, the dew point temperature of the ambient air is around 26℃. At this time, the temperature of the lubricating oil after throttling and pressure reduction measured by the first temperature sensor is 31.5℃, and the lubricating oil flow rate measured by the oil flow meter is 10L / min. It is known that the specific heat capacity of the lubricating oil in the helium compressor is 2.0kJ / (kg·K), and the heat generated by the frequency converter under high load is 300W. According to the heat calculation formula Q=cm∆t, the lubricating oil temperature at the outlet of the cooling plate is 32.6℃. The excellent heat storage capacity of the lubricating oil makes its own temperature rise very small. After passing through the cooling plate, it enters the pressure tank at room temperature and low pressure. The oil temperature at the outlet of the cooling plate is 32.6℃, which is higher than the ambient air dew point temperature of 26℃. The heat exchange temperature of the lubricating oil ensures that the electronic control unit of the helium compressor is cooled to the optimal operating temperature range, while also effectively avoiding the condensation problem of the electronic control unit. This allows the operation of the helium compressor to be unrestricted by the ambient temperature, eliminating the need for special sealing or dehumidification treatment of the electronic control unit, thus improving safety.

[0023] Example 2

[0024] like Figure 2As shown, this embodiment provides a variable frequency helium compressor with an electronically controlled cooling circulation system. The difference from Embodiment 1 is that a three-way diverter valve 9 is added at the outlet of the first throttling device 7. The three-way diverter valve 9 divides the room-temperature lubricating oil cooled by the water-cooled heat exchanger 4 into two paths. One path connects to the inlet pipe of the cooling plate to cool and control the temperature of the electronic control unit 3. The other path connects to the outlet pipe of the cooling plate and mixes with the heated lubricating oil in the cooling plate. After balancing the oil temperature, the mixture enters the scroll compressor 1. A second temperature sensor 10 is installed on the housing of the electronic control unit 3 to monitor the housing temperature and adjust the three-way diverter valve 9 to control the amount of lubricating oil entering the cooling plate. In this embodiment, the second temperature sensor 10 reads the housing temperature of the electronic control unit in real time and adjusts the opening of the three-way diverter valve accordingly to ensure that the electronic control unit always operates within the optimal temperature range. When the temperature detected by the second temperature sensor is higher than the optimal operating temperature range of the electronic control unit, the opening of one of the three-way diverter valves connected to the cooling plate inlet pipe increases, the flow rate of room temperature lubricating oil in the cooling plate increases, the heat exchange is enhanced, and the cooling capacity of the electronic control unit is strengthened. When the temperature detected by the second temperature sensor is lower than the optimal operating temperature range of the electronic control unit, the opening of one of the three-way diverter valves connected to the cooling plate inlet pipe decreases or even closes, the flow rate of room temperature lubricating oil in the cooling plate decreases, the heat exchange decreases, and the electronic control unit does not need to be cooled.

[0025] Example 2 utilizes a three-way diverter valve to regulate the flow rate of circulating lubricating oil within the compressor system. This eliminates the need to adjust the external chiller unit, enabling precise temperature control of the electronic control unit. Compared to Example 1, this method is suitable for situations where adjusting the flow rate and temperature of the external chiller unit is inconvenient.

Claims

1. A variable frequency helium compressor with an electrically controlled cooling cycle system, comprising a helium compressor (2) with a scroll compression package (1) and an electric control unit (3), characterized in that, The electric control cooling circulation system is also used for cooling the electric control unit (3), and the high-temperature lubricating oil discharged from the oil discharge port (101) of the scroll compression package (1) is cooled by the water-cooled heat exchanger (4), and then flows through the cooling plate (5) to cool the electric control unit (3), and the outlet of the cooling plate (5) is connected to the oil return port (102) of the scroll compression package (1).

2. The variable frequency helium compressor with electrically controlled cooling cycle system of claim 1, wherein, The first filter (7) for filtering impurities in the lubricating oil and the first throttling device (6) for throttling and depressurizing the lubricating oil in the pipeline are sequentially connected between the water-cooled heat exchanger (4) and the cooling plate (5).

3. The variable frequency helium compressor with electrically controlled cooling cycle system of claim 2, wherein, The temperature of the lubricating oil after being throttled and depressurized by the first throttling device (6) and then entering the cooling plate (5) is higher than the dew point temperature of the working environment.

4. The variable frequency helium compressor with electrically controlled cooling cycle system of claim 2, wherein, The electric control cooling circulation system further comprises a first temperature sensor (8) arranged at the inlet of the cooling plate (5), and the first temperature sensor (8) detects the temperature of the lubricating oil entering the cooling plate (5), so as to realize the regulation and control of the lubricating oil temperature of the cooling plate (5) by adjusting the water inflow and temperature of the water-cooled heat exchanger (4).

5. The variable frequency helium compressor with electrically controlled cooling cycle system of claim 1, wherein, The first filter (7) for filtering impurities in the lubricating oil, the first throttling device (6) for throttling and depressurizing the lubricating oil in the pipeline and the three-way diverter valve (9) are sequentially connected between the water-cooled heat exchanger (4) and the cooling plate (5), and the three-way diverter valve (9) is connected to the inlet pipe of the cooling plate (5) in one way and connected to the outlet pipe of the cooling plate (5) in another way.

6. The variable frequency helium compressor with electrically controlled cooling cycle system of claim 5, wherein, A second temperature sensor (10) is arranged on the shell of the electric control unit (3) to monitor the shell temperature of the electric control unit (3) to adjust the three-way diverter valve (9) to control the amount of lubricating oil entering the cooling plate (5).

7. The variable frequency helium compressor with electrically controlled cooling cycle system of claim 1, wherein, The water-cooled heat exchanger (4) also cools the high-temperature helium gas discharged from the scroll compression package (1), and the high-temperature helium gas of the exhaust port (103) is cooled by the water-cooled heat exchanger (4) and then enters the oil-gas separator (21) for separation.

8. The variable frequency helium compressor with electrically controlled cooling cycle system of claim 1, wherein, The water-cooled heat exchanger (4) is a double-pipe heat exchanger or a plate heat exchanger.

Images