Electric scroll compressor oil pumping system and method

Abstract

The invention relates to the field of air conditioner compressors, in particular to an electric scroll compressor oil pumping system and method.The electric scroll compressor oil pumping system comprises an electric scroll compressor, an oil-gas separator, an oil cooler, an oil filter, an oil storage tank and a PLC control unit; sensors are arranged in the electric scroll compressor, the oil-gas separator, the oil cooler, the oil filter and the oil storage tank and are in signal connection with the PLC control unit, so that the problems of oil oxidation caused by high temperature and difficulty in low-temperature starting at the present stage and influence on the system stability are solved; mechanical wear and motor damage caused by frequent start and stop and impurity sensitivity; due to low-load energy efficiency sudden drop and frequency conversion control oscillation, the operation economy is reduced; the adaptability to high-viscosity or corrosive oil products is poor, and the maintenance cost is high.

Description

Technical Field

[0001] The present invention relates to the field of air-conditioning compressors, and in particular to an oil extraction system and method for an electric scroll compressor. Background Art

[0002] The oil extraction system of electric scroll compressors for automotive air conditioners is primarily responsible for lubrication, sealing, and cooling, ensuring efficient and stable compressor operation while safeguarding the reliability and lifespan of the air conditioning system. However, electric scroll compressors face numerous challenges within the oil extraction system, including: insufficient oil sealing, leading to oil seepage or reverse leakage, affecting lubrication and exhaust purity; low oil-gas separation efficiency, making it difficult to capture tiny oil droplets, increasing fuel consumption and contamination risks; high-temperature-induced oil oxidation and low-temperature startup difficulties, impacting system stability; frequent starts and stops and impurity sensitivity leading to mechanical wear and motor damage; sudden drops in low-load energy efficiency and variable frequency control oscillation, reducing operational economics; and poor adaptability to high-viscosity or corrosive oils, limiting their application scenarios. Furthermore, high maintenance costs further increase operational burdens.

[0003] In summary, an electric scroll compressor oil extraction system and method are proposed to solve the problems raised in the above background technology. Summary of the Invention

[0004] The purpose of the present invention is to provide an electric scroll compressor oil pumping system and method, which uses sensors for detection and monitoring and a PLC control unit for logical control to improve the trouble-free time of the electric scroll compressor under oil pumping conditions and solve the problems raised in the above background technology.

[0005] An electric scroll compressor oil pumping method, the specific steps are as follows: Step S10: The electric oil pump is started and an oil pressure of 0.2 MPa is pre-established within 3 seconds; In step S20, the electric scroll compressor is started, and the oil and gas mixture is extracted through the oil suction port. The oil enters the scroll lubrication point of the electric scroll compressor from the oil storage tank for lubrication. The temperature sensor of the compressor housing determines whether the oil temperature is between -20°C and 120°C, and whether the pressure at the oil suction port is between -0.5MPa and 1.5MPa. If not, the oil circuit is closed. If so, step S30 is executed. In step S30, the mixture carrying lubricating oil enters the oil-gas separator, the gas is discharged, and the oil is deposited. When the response time of the solenoid valve in the oil-gas separator exceeds 50ms, the solenoid valve is closed, and it is determined whether the pressure of the oil outlet of the electric scroll compressor is between 0-3MPa. If not, the oil circuit is closed. If so, step S40 is executed. Step S40: The separated oil enters the oil cooler and oil filter for cooling and filtration and then returns to the compressor for lubrication.

[0006] It is further defined that it includes an electric scroll compressor, an oil-gas separator, an oil cooler, an oil filter, an oil storage tank and a PLC control unit, and the electric scroll compressor, oil-gas separator, oil cooler, oil filter and oil storage tank are all provided with sensors and are signal-connected to the PLC control unit.

[0007] It is further defined that the oil suction port and the oil outlet port of the electric scroll compressor are both provided with pressure sensors, and a temperature sensor is provided on the compressor housing. The electric scroll compressor adopts an oil-resistant material with an aluminum alloy scroll disk and a Teflon coating. Different oil pumping rates are matched by exhaust volume, and can be adjusted according to different oil well depths. The electric scroll compressor is also provided with a variable frequency motor.

[0008] It is further defined that the oil-gas separator adopts a multi-stage centrifugal and coalescing filter element, and an electric oil pump, an ultrasonic liquid level sensor and a normally closed solenoid valve are installed in the oil storage tank. The electric oil pump, ultrasonic liquid level sensor and normally closed solenoid valve are all connected to the PLC control unit signal.

[0009] It is further defined that the oil cooler is provided with three-stage filters, and the filtering precisions are 25 μm, 10 μm and 3 μm from high to low.

[0010] It is further defined that the base of the electric scroll compressor is equipped with a rubber shock-absorbing pad, the oil extraction pipeline adopts a flexible connection, the joint in the oil extraction pipeline adopts a ferrule joint, and the sealing part of the ferrule joint adopts a double-lip sealing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Schematic diagram of the logic control flow of the present invention. DETAILED DESCRIPTION

[0012] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments. Example

[0013] like Figure 1As shown, an electric scroll compressor oil pumping system includes an electric scroll compressor, an oil-gas separator, an oil cooler, an oil filter, an oil storage tank and a PLC control unit. The electric scroll compressor adopts an aluminum alloy scroll disk and an oil-resistant material with a Teflon coating. Different oil pumping rates are matched by exhaust volume matching and adjusted according to different oil well depths. The oil suction port and oil outlet of the electric scroll compressor are both provided with pressure sensors, and a temperature sensor is provided on the compressor housing. The electric scroll compressor is also provided with a variable frequency motor. The pressure sensor, temperature sensor and variable frequency motor are all connected to the PLC control unit signal. At the same time, a pressure relief valve is also provided in the electric scroll compressor to avoid overload. The oil-gas separator adopts a multi-stage centrifugal and coalescing filter element with a separation efficiency of >99.5%. The capacity of the oil storage tank is ≥ The oil volume of the compressor is 1.5 times that of the circulating oil. An electric oil pump, an ultrasonic liquid level sensor and a normally closed solenoid valve are installed in the oil storage tank. The electric oil pump, ultrasonic liquid level sensor and normally closed solenoid valve are all connected to the PLC control unit signal. The oil cooler is plate-type water-cooled. The oil cooler is also equipped with a temperature sensor. The temperature sensor is connected to the PLC control unit signal to maintain the oil temperature at a high temperature of 40-60°C and start water cooling. The oil cooler is equipped with a three-stage filter with filtration accuracy of 25μm, 10μm and 3μm from high to low. A rubber shock-absorbing pad is installed on the base of the electric scroll compressor. The oil extraction pipeline adopts a flexible connection. The joints in the oil extraction pipeline adopt a compression joint. The sealing of the compression joint adopts a double-lip sealing ring made of fluororubber to enhance the sealing of the connection.

[0014] A method for pumping oil from an electric scroll compressor, comprising the following steps: Step S10: The electric oil pump is started and an oil pressure of 0.2 MPa is pre-established within 3 seconds; In step S20, the electric scroll compressor is started, and the oil and gas mixture is extracted through the oil suction port. The oil enters the scroll lubrication point of the electric scroll compressor from the oil storage tank for lubrication. The temperature sensor of the compressor housing determines whether the oil temperature is between -20°C and 120°C, and whether the pressure at the oil suction port is between -0.5MPa and 1.5MPa. If not, the oil circuit is closed. If so, step S30 is executed. In step S30, the mixture carrying lubricating oil enters the oil-gas separator, the gas is discharged, and the oil is deposited. When the response time of the solenoid valve in the oil-gas separator exceeds 50ms, the solenoid valve is closed, and it is determined whether the pressure of the oil outlet of the electric scroll compressor is between 0-3MPa. If not, the oil circuit is closed. If so, step S40 is executed. Step S40: The separated oil enters the oil cooler and oil filter for cooling and filtration and then returns to the compressor for lubrication.

[0015] It is also equipped with automatic start-stop control logic. When the oil level is lower than the threshold, the solenoid valve is activated to replenish oil. When it is higher than the threshold, the pump is stopped. When the temperature is higher than 90°C, the machine is shut down. When it is lower than 0.2MPa, an alarm is issued. When the current is greater than 110% of the rated value, it indicates that the motor is overloaded and the power supply is cut off. The speed is dynamically adjusted according to the load (PID control), saving 15%-30% energy.

[0016] The above is a detailed introduction to an electric scroll compressor oil extraction method provided by the present invention. The description of the specific embodiment is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for pumping oil from an electric scroll compressor, characterized in that: The specific steps are as follows: Step S10: The electric oil pump is started and an oil pressure of 0.2 MPa is pre-established within 3 seconds; In step S20, the electric scroll compressor is started, and the oil and gas mixture is extracted through the oil suction port. The oil enters the scroll lubrication point of the electric scroll compressor from the oil storage tank for lubrication. The temperature sensor of the compressor housing determines whether the oil temperature is between -20°C and 120°C, and whether the pressure at the oil suction port is between -0.5MPa and 1.5MPa. If not, the oil circuit is closed. If so, step S30 is executed. In step S30, the mixture carrying lubricating oil enters the oil-gas separator, the gas is discharged, and the oil is deposited. When the response time of the solenoid valve in the oil-gas separator exceeds 50ms, the solenoid valve is closed, and it is determined whether the pressure of the oil outlet of the electric scroll compressor is between 0-3MPa. If not, the oil circuit is closed. If so, step S40 is executed. Step S40: The separated oil enters the oil cooler and oil filter for cooling and filtration and then returns to the compressor for lubrication.

2. A system suitable for the oil extraction method of an electric scroll compressor according to claim 1, characterized in that: The system comprises an electric scroll compressor, an oil-gas separator, an oil cooler, an oil filter, an oil storage tank and a PLC control unit. The electric scroll compressor, the oil-gas separator, the oil cooler, the oil filter and the oil storage tank are all provided with sensors and are connected to the PLC control unit by signal.

3. The oil pumping system for an electric scroll compressor according to claim 2, characterized in that: The oil suction port and oil outlet of the electric scroll compressor are both provided with pressure sensors, and a temperature sensor is provided on the compressor housing. The electric scroll compressor adopts an oil-resistant material with an aluminum alloy scroll disk and a Teflon coating. Different oil pumping rates are matched by exhaust volume matching and adjusted according to different oil well depths. The electric scroll compressor is also provided with a variable frequency motor.

4. The oil pumping system for an electric scroll compressor according to claim 2, characterized in that: The oil-gas separator adopts a multi-stage centrifugal and coalescing filter element, and an electric oil pump, an ultrasonic liquid level sensor and a normally closed solenoid valve are arranged in the oil storage tank. The electric oil pump, ultrasonic liquid level sensor and normally closed solenoid valve are all connected to the PLC control unit signal.

5. The oil extraction system for an electric scroll compressor according to claim 2, characterized in that The oil cooler is equipped with three-stage filters, and the filtration accuracy is 25μm, 10μm and 3μm from high to low.

6. The oil extraction system for an electric scroll compressor according to claim 2, characterized in that: The base of the electric scroll compressor is equipped with a rubber shock-absorbing pad, the oil extraction pipeline adopts a flexible connection, the joint in the oil extraction pipeline adopts a ferrule joint, and the sealing part of the ferrule joint adopts a double-lip sealing ring.

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