A semi-hermetic screw compressor with automatically continuously adjustable volumetric ratio

Abstract

The present invention belongs to a semi-hermetic screw compressor with an automatically continuously adjustable internal volume ratio. The problem to be solved is that in the background art: the motor is installed on the suction side of the compressor, and the space is narrow, resulting in difficulties in designing the internal volume ratio adjustment mechanism. The on and off of a single solenoid valve cannot achieve the automatic continuous adjustment of the internal volume ratio slide valve. The key points of the technical solution adopted to solve this technical problem are: Part A and Part B form a combined semi-hermetic screw compressor through the connection between the exhaust end seat and the intermediate body; the internal volume ratio piston cavity is divided into an internal volume ratio piston right cavity and an internal volume ratio piston left cavity by the internal volume ratio piston, and the internal volume ratio loading solenoid valve and the internal volume ratio unloading solenoid valve control the power oil circuit to communicate with or cut off the internal volume ratio piston right cavity and the internal volume ratio piston left cavity. It is applicable to refrigeration compressor equipment.

Description

[0001] Technical Field: The present invention belongs to the refrigeration technology, and specifically relates to a semi-hermetic screw compressor with an automatically continuously adjustable internal volume ratio.

[0002] Background Art: Energy conservation is the primary energy source, and it is the main path to achieve carbon neutrality in the future. Solving the over-compression and under-compression of screw compressors, that is, achieving adjustable internal volume ratio of the compressor, is an important measure to improve the COP. For existing suction-cooled semi-hermetic screw compressors or refrigerant injection-cooled semi-hermetic screw compressors, the motor is installed on the suction side of the compressor, and the motor drive shaft and the compressor rotor drive shaft are made into one body. In order to reduce the deformation of the motor drive shaft and control the gap between the motor stator and the motor rotor within a safe range, the space between the motor and the compressor rotor tooth profile is narrow, and the outer dimension of the motor is much larger than the diameter of the compressor rotor. Considering these factors together, it is difficult to design the internal volume ratio adjustment mechanism of the semi-hermetic screw compressor, and the traditional structure semi-hermetic screw compressors all have a fixed internal volume ratio. The authorized announcement number CN105626520B "A Semi-Enclosed Screw Compressor with Adjustable Internal Volume Ratio", its structural form can achieve manual intermittent adjustment of the internal volume ratio. However, in its hydraulic control scheme, the Vi adjustment piston only has a cavity at the top, and the lower part is a cut surface that directly contacts the end face of the Vi slide valve, and no cavity can be formed. And only relying on the on and off of a solenoid valve connected to the top cavity, it is impossible to reliably control the hydraulic oil to enter and exit the cavity, and thus it is impossible to achieve automatic continuous adjustment of the internal volume ratio slide valve.

[0003] SUMMARY OF THE INVENTION: The object of the present invention is to provide a semi-hermetic screw compressor with an automatically continuously adjustable internal volume ratio, so as to solve the problems existing in the background technology: the motor is installed on the suction side of the compressor, and the space is narrow, resulting in difficulties in designing the internal volume ratio adjustment mechanism. The on and off of a single solenoid valve cannot achieve the automatic continuous adjustment of the internal volume ratio slide valve. The technical solution adopted to solve this technical problem is: a semi-hermetic screw compressor with an automatically continuously adjustable internal volume ratio. Part A includes: an intermediate partition divides the inner cavity of the oil cylinder body into an energy adjustment piston cavity and an internal volume ratio piston cavity. An energy adjustment solenoid valve is provided on the oil cylinder body. An intake end seat is arranged between the oil cylinder body and the machine body. The internal volume ratio piston in the internal volume ratio piston cavity is connected to the internal volume ratio slide valve through an internal volume ratio guide rod. The internal volume ratio slide valve slides in the cavity where the intake end seat and the machine body are connected. The machine body is connected to the exhaust end seat. The energy adjustment piston in the energy adjustment piston cavity is connected to the energy adjustment slide valve through an energy adjustment guide rod. The energy adjustment slide valve slides in the cavity where the machine body and the exhaust end seat are connected. Part B includes: the rotor is connected to the motor shaft through a coupling. The motor rotor, motor stator and motor shaft are arranged in the motor housing. The intermediate body is connected to the exhaust end seat and the motor housing on both sides to form a sealed structure. The junction box is arranged on the intermediate body or the motor housing. It is characterized in that: Part A and Part B form a combined structure of a semi-hermetic screw compressor through the connection between the exhaust end seat and the intermediate body; the oil cylinder body is provided with an internal volume ratio increasing solenoid valve and an internal volume ratio decreasing solenoid valve; the internal volume ratio piston cavity is divided into an internal volume ratio piston right cavity and an internal volume ratio piston left cavity by the internal volume ratio piston. The internal volume ratio increasing solenoid valve and the internal volume ratio decreasing solenoid valve control the power oil circuit to be connected or cut off with the internal volume ratio piston right cavity and the internal volume ratio piston left cavity. By changing the position and / or quantity of the oil holes corresponding to the internal volume ratio increasing solenoid valve and the internal volume ratio decreasing solenoid valve, the stepped adjustment of the internal volume ratio can be achieved. The internal volume ratio increasing solenoid valve and the internal volume ratio decreasing solenoid valve are connected to the internal volume ratio piston cavity through pipelines.

[0004] Compared with the prior art, the present invention has the following beneficial effects: due to the adoption of the above technical solution, on the one hand, the installation position of the motor in part B is at one end of the semi-hermetic screw compressor, and the terminal box, the exhaust end and the motor form a closed area, realizing a semi-closed structure and reserving installation space for part A; on the other hand, part A has sufficient space to install the internal volume ratio load-increasing solenoid valve and the internal volume ratio load-reducing solenoid valve. When the internal volume ratio load-reducing solenoid valve in part A is energized, power oil is pumped into the right cavity of the internal volume ratio piston, and the power oil in the left cavity of the internal volume ratio piston is discharged at the same time, pushing the internal volume ratio piston and driving the internal volume ratio slide valve to move to the left through the internal volume ratio guide rod, thereby reducing the internal volume ratio. When the internal volume ratio load-increasing solenoid valve is energized, power oil is pumped into the left cavity of the internal volume ratio piston, and the power oil in the right cavity of the internal volume ratio piston is discharged at the same time, pushing the internal volume ratio piston and driving the internal volume ratio slide valve to move to the right through the internal volume ratio guide rod, thereby increasing the internal volume ratio, thereby realizing automatic and continuous adjustment of the internal volume ratio and solving the problems of over-compression and under-compression of the screw compressor. On the other hand, part A and part B form a combined structure through the connection between the exhaust end seat and the intermediate body, forming an organic combination of part A and part B. The two are scientifically coordinated and complement each other. They have the advantages of automatic and continuous adjustment of the content volume ratio of part A, and the advantages of the semi-enclosed structure of part B, resulting in an excellent combination effect.

[0005] Description of the drawings: Figure 1 It is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0006] Example 1: Reference Figure 1, a semi-hermetic screw compressor with an automatically continuously adjustable internal volume ratio. Part A includes: an intermediate partition 21 divides the inner cavity of the oil cylinder body 1 into an energy regulation piston cavity and an internal volume ratio piston cavity. An energy regulation solenoid valve 22 is provided on the oil cylinder body 1. An intake end seat 18 is arranged between the oil cylinder body 1 and the machine body 6. The internal volume ratio piston 3 in the internal volume ratio piston cavity is connected to the internal volume ratio slide valve 5 through an internal volume ratio guide rod 4. The internal volume ratio slide valve 5 slides in the cavity where the intake end seat 18 and the machine body 6 are connected. The machine body 6 is connected to the exhaust end seat 7. The energy regulation piston 2 in the energy regulation piston cavity is connected to the energy regulation slide valve 16 through an energy regulation guide rod 17. The energy regulation slide valve 16 slides in the cavity where the machine body 6 and the exhaust end seat 7 are connected. Part B includes: the rotor 8 is connected to the motor shaft 13 through a coupling 9. The motor rotor 14, the motor stator 15 and the motor shaft 13 are arranged in the motor housing 12. The intermediate body 10 is connected to the exhaust end seat 7 and the motor housing 12 on both sides to form a sealed structure. The junction box 11 is arranged on the intermediate body 10 or the motor housing 12. It is characterized in that: Part A and Part B form a combined structure of a semi-hermetic screw compressor through the connection between the exhaust end seat 7 and the intermediate body 10; an internal volume ratio increasing solenoid valve 19 and an internal volume ratio decreasing solenoid valve 20 are provided on the oil cylinder body 1; the internal volume ratio piston cavity is divided into an internal volume ratio piston right cavity and an internal volume ratio piston left cavity by the internal volume ratio piston 3. The internal volume ratio increasing solenoid valve 19 and the internal volume ratio decreasing solenoid valve 20 control the power oil circuit to be connected or cut off from the internal volume ratio piston right cavity and the internal volume ratio piston left cavity. By changing the position and / or quantity of the oil holes corresponding to the internal volume ratio increasing solenoid valve 19 and the internal volume ratio decreasing solenoid valve 20, the stepwise regulation of the internal volume ratio is realized. The internal volume ratio increasing solenoid valve 19 and the internal volume ratio decreasing solenoid valve 20 can also be connected to the internal volume ratio piston cavity through pipelines.

Claims

1. A semi-hermetic screw compressor with an automatically and continuously adjustable internal volume ratio, wherein part A comprises: The middle partition (21) divides the inner cavity of the oil cylinder body (1) into an energy regulating piston cavity and an internal volume ratio piston cavity. An energy regulating solenoid valve (22) is provided on the oil cylinder body (1). An air intake end seat (18) is provided between the oil cylinder body (1) and the machine body (6). The internal volume ratio piston (3) of the internal volume ratio piston cavity is connected to the internal volume ratio slide valve (5) through the internal volume ratio guide rod (4). The internal volume ratio slide valve (5) slides in the cavity connected to the air intake end seat (18) and the machine body (6). The machine body (6) is connected to the exhaust end seat (7). The energy regulating piston (2) of the energy regulating piston cavity is connected to the exhaust end seat (7) through the energy regulating guide rod (4). The rod (17) is connected to the energy regulating slide valve (16), and the energy regulating slide valve (16) slides in a cavity connected to the body (6) and the exhaust end seat (7); the B part includes: a rotor (8) connected to the motor shaft (13) through a coupling (9), a motor rotor (14), a motor stator (15) and a motor shaft (13) are arranged in the motor housing (12), the exhaust end seat (7) and the motor housing (12) are connected on both sides of the intermediate body (10) to form a sealing structure, and a junction box (11) is arranged on the intermediate body (10) or the motor housing (12); it is characterized in that: the A part and the B part are connected through The connection between the exhaust end seat (7) and the intermediate body (10) forms a semi-hermetic screw compressor of a combined structure; the oil cylinder body (1) is provided with a volume ratio load-increasing solenoid valve (19) and a volume ratio load-reducing solenoid valve (20), which are connected to the volume ratio piston cavity through a pipeline; the volume ratio piston cavity is divided into a volume ratio piston right cavity and a volume ratio piston left cavity by the volume ratio piston (3), and the volume ratio load-increasing solenoid valve (19) and the volume ratio load-reducing solenoid valve (20) control the power oil circuit and the volume ratio piston right cavity, The left cavity of the volume ratio piston is connected or cut off, the volume ratio load reduction solenoid valve is energized, the power oil is pumped into the right cavity of the volume ratio piston, and the power oil in the left cavity of the volume ratio piston is discharged at the same time, the volume ratio piston is pushed and the volume ratio slide valve is driven to move to the left through the volume ratio guide rod, and the volume ratio is reduced; the volume ratio load increase solenoid valve is energized, the power oil is pumped into the left cavity of the volume ratio piston, and the power oil in the right cavity of the volume ratio piston is discharged at the same time, the volume ratio piston is pushed and the volume ratio slide valve is driven to move to the right through the volume ratio guide rod, and the volume ratio is increased, thereby realizing automatic and continuous adjustment of the volume ratio.

2. A semi-hermetic screw compressor with automatically and continuously adjustable internal volume ratio according to claim 1, characterized in that: The positions and / or numbers of the oil holes corresponding to the internal volume ratio load-increasing solenoid valve (19) and the internal volume ratio load-reducing solenoid valve (20) are changed to achieve step-by-step regulation of the internal volume ratio.

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