Compressor unit

Description

[0001] Technical field

[0002] The utility model relates to compressor engineering, namely to devices for regulating the performance of piston compressor units.

[0003] Technology Level

[0004] A piston compressor with a hydraulic drive is known, consisting of two cylinders located on the same axis, a piston hydraulic drive, a common piston rod and hydraulic drive, a pump, and an automatic hydraulic fluid distribution system. The drive pump supplies the working fluid to the system, where it is distributed among the cavities of the hydraulic drive, the main spool valve, and the auxiliary spool valve. When the hydraulic drive is operating, the common piston rod, in its extreme positions, interacts with the auxiliary spool valve via clutches and rods, switching its positions and opening hydraulic channels for switching the main spool valve, thereby enabling compressor drive operation.A disadvantage of the known compressor is the low degree of compression; this limitation is caused by an increase in the temperature of the compressed gas, which, in turn, leads to increased wear of the compression rings, to linear expansion of the cylinder and gas piston, as a result of which leaks of compressed gas increase, reducing the efficiency of the compressor (see SU89087).

[0005] A piston compressor is known that comprises a cylindrical housing with two oppositely mounted compressor and drive cylinders. Each cylinder contains pistons secured to a common piston rod. The compressor comprises inlet and outlet lines connecting the cylinder's working chambers and a system for supplying the working fluid to the cylinder's working chambers, a working fluid source with pressure and return lines, a distribution device, and a heat exchanger. The housing is provided with a cooling jacket and contains a plunger micropump, which is the working chamber formed by the housing cover and the end of the common piston rod, which serves as the plunger of the micropump. Its other end is mechanically connected to the distribution device. The heat exchanger is installed in the pressure line and is capable of converting the working fluid into a vaporous state.An additional heat exchanger is installed in the drain line, capable of converting a vaporous working fluid, such as freon, into a liquid state. The drain line is connected via a pressure relief valve to the working fluid source, a tank, which is connected via a suction line to a micropump. A check valve is installed in the pressure line at the inlet to the heat exchanger (see RU 2638143).

[0006] A hydraulic compressor is known that has a fixed piston and a fixed compression or outer cylinder. A drive or intermediate cylinder is located between the piston and the outer cylinder. A compression chamber is formed between the drive cylinder and the outer cylinder. Drive fluid is pumped into and released from the inner chamber of the drive cylinder to cause reciprocating motion of the drive cylinder. The drive fluid also provides cooling for the interior of the compressor (see US 11680560).

[0007] A technical solution known from the prior art, adopted as the closest analogue, is a multi-stage gas compressor consisting of two units with central hydraulic drives and oppositely arranged cylinders. The hydraulic drive is a cylinder with two chambers separated by a piston. The hydraulic piston of the first unit is connected to the pistons of the first and third compression stages, and the hydraulic piston of the second unit is connected to the pistons of the second and fourth stages, respectively. The first and second-stage compression cylinders are equipped with cooling jackets, and the third and fourth-stage compression cylinders are located within the hydraulic drive cylinder. Gas is supplied (discharged) to the third and fourth-stage compression cylinders through a pipeline located inside the first and second-stage compression cylinders, coaxial with their housings.

[0008] A disadvantage of the known solution (see EP0064177B1) is the lack of cooling of the third and fourth stages of compression. Since the gas is supplied to them through pipelines located inside the first and second stage cylinders, which have only external cooling, these pipelines will always be "hot", receiving heat from the compressed gas in these cylinders. As a result, the gas after the second stage of compression and the refrigerator enters the "hot" pipeline, is heated in it and enters the third stage cylinder, where, being compressed, it heats up even more and exits through the same pipeline, heating it up even more. The gas then enters the fourth stage of compression through the refrigerator, where the same processes occur as in the third stage. The hot pipelines will also heat the gas entering the first and second stages of compression, reducing their mass flow rate.

[0009] The technical result is an increase in the operating life of the compressor unit.

[0010] The technical result is achieved by a compressor unit comprising a base formed as a single frame with a drive pump mounted thereon. The drive pump is connected via at least one hydraulic distributor to a central hydraulic drive. The drive contains a piston with a double-ended piston rod, connected to oppositely arranged compression stages, each of which includes a pneumatic cylinder with a piston and a compression chamber. The pneumatic cylinder is equipped with a cooling jacket, and the compression chambers located within the compression stages are elongated, with the length of each compression chamber ranging from 10 to 15 mm.

[0011] The cooling jacket is made in the form of external and internal contours adjacent to the pneumatic cylinder.

[0012] The cooling jacket is designed with the possibility of connection from the hydraulic drive drain.

[0013] Brief description of drawings

[0014] The claimed utility model is explained by an illustration.

[0015] The figure shows a compressor unit.

[0016] Where: 1 - base; 2 - drive pump; 3, 5, 6, 22, 26, 31 - line; 4, 15 - hydraulic distributor; 7 - central hydraulic drive; 7a, 7b - hydraulic drive chambers; 8 - piston with double-sided rod; 9, 10 - pistons; 11, 13 - pneumatic cylinder; 12 - first stage compression block; 14 - second stage compression block; 16, 17 - safety valve; 18 - supply tank; 19 - oil cooler; 20, 24, 28 - inlet valve; 21 - outlet valve; 23, 29 - cooler; 25, 30 - cooling jacket; 27, 32 - check valve.

[0017] The compressor unit comprises a base 1 made in the form of a single frame with a drive pump 2 mounted on it, which is connected to a hydraulic distributor 4 via a line 3. The hydraulic distributor 4 is connected by lines 5, 6 to a central hydraulic drive 7 formed by chambers 7a and 7b and containing a piston with a double-sided rod 8. The piston 8 has a rigid connection with pistons 9 and 10 located in the pneumatic cylinder 11 of the first-stage compression unit 12 and in the pneumatic cylinder 13 of the second-stage compression unit 14, respectively. The hydraulic distributor 4 is connected to the hydraulic distributor 15 by a line (not shown in the figure). A safety valve 16 is located on the line 3, and safety valves 17 are located on the lines 5 and 6. Safety valves 16 and 17 discharge the working fluid into the supply tank 18 in cases where the pressure in the pressure lines exceeds the opening pressure of the safety valve.The supply tank 18, being a source of the working fluid, is connected to the drive pump 2 for feeding the entire system, and, being a reservoir for collecting the working fluid after cooling the pneumatic cylinders 13, 11, is connected to the oil cooler of the liquid 19 for collecting the working fluid. In the first stage compression block 12 there is a pneumatic cylinder 11, inside of which there is a piston 9. Gas from the source is supplied to the first stage compression block 12 into the pneumatic cylinder 11 through the inlet valve 20. The outlet valve 21 of the pneumatic cylinder 11 is connected to the gas cooler 23 by the line 22. In the second stage compression block 14 there is a pneumatic cylinder 13, inside of which there is a piston 10. The drive pump 2 creates pressure of the working fluid in the line 3, from where the fluid enters the chamber 7b of the hydraulic drive 7 through the hydraulic distributor 4 and the line 6, setting the piston 8 of the hydraulic cylinder 7 in motion. The piston 8 of the hydraulic cylinder, having a rigid connection with the pistons 9 and 10, sets them in motion.By filling chamber 7b, piston 8 compresses the gas in pneumatic cylinder 7. Having reached the opening pressure of exhaust valve 21, the gas exits pneumatic cylinder 11, enters line 22, is cooled in gas cooler 23, and through inlet valve 24 enters pneumatic cylinder 13, the second-stage compression stage. The compression chambers are elongated, with a chamber length of 10 to 15 mm. Using a compression chamber shorter than 10 mm will result in insufficient air compression. The chamber will not be able to accumulate the required amount of air to create the required operating pressure. This will reduce the force acting on the piston and reduce the efficiency of the cylinder and the compressor unit as a whole. Using a compression chamber longer than 15 mm reduces air compression efficiency and increases the risk of piston rod load, which will reduce the efficiency of the compressor unit as a whole. As an example, the length of the compression chamber ψ=Sn / D, where Sn is the piston stroke, D is the piston diameter, ψ≥10.

[0018] The working fluid, displaced from chamber 7a along line 5 through hydraulic distributors 4 and 15, enters cooling jacket 25, heats up, cooling pneumatic cylinder 11, leaves the cooling jacket into line 26, through check valve 27, enters oil cooler 19 and then into supply tank 18.

[0019] Using the unit on a single frame ensures mobility and rigidity of the structure, since the frame dampens all possible vibrations from the operation of the compressor unit, reducing the load on the components.

[0020] Piston 8 of hydraulic drive 7, having reached the extreme position, is fixed automatically (not shown in the figure), after which hydraulic distributors 4 and 15 are switched, and the working fluid from the drive pump through hydraulic distributor 4 enters the line 5, the filling of chamber 7a of hydraulic drive 7 begins, and piston 8 moves in the opposite direction, while the pneumatic cylinder 11 of the first-stage compression unit 12 is filled and gas is compressed in the pneumatic cylinder 13 of the second-stage compression unit 14. Gas from the second-stage compression unit 14, having reached the opening pressure of the exhaust valve 28, is supplied to the consumer through the gas cooler 29. The working fluid, displaced from 7b along line 6, through hydraulic distributors 4 and 15, enters cooling jacket 30, heats up, cooling pneumatic cylinder 13, leaves the cooling jacket into line 31, through check valve 32, enters oil cooler 19 and then into supply tank 18.Each pneumatic cylinder (11, 13) is equipped with a cooling jacket consisting of an outer and inner circuit adjacent to the pneumatic cylinder. Hydraulic fluid, supplied by the hydraulic distributor, is fed into the outer circuit through a line. The fluid circulates within the circuit, cooling the pneumatic cylinder and reducing the temperature of the compressed gas. Heated hydraulic fluid exits the circuit through a line equipped with a check valve and then enters the working fluid cooler for cooling before being discharged into the supply tank. Thus, the outer cooling circuit effectively removes heat from the outer surface of the pneumatic cylinder, reducing the thermal impact on the pneumatic cylinder components and the thermal expansion of the compressed gas. This reduces the load on the compressor components, improves operational stability, and extends the compressor's service life.

[0021] The working fluid is supplied to the internal cooling circuit through a line from the hydraulic distributor and flows through the circuit, removing heat from the hot working surfaces of the pneumatic cylinder. Heated working fluid exits the internal cooling circuit through a line equipped with a check valve and is directed to the working fluid cooler for cooling before being discharged into the supply tank. Internal cooling removes heat directly from the inner surface of the pneumatic cylinder, reducing thermal stress and component expansion. This reduces the load on compressor components, improves operational stability, and extends the compressor's service life. Thus, a cooling system consisting of external and internal cooling improves compressor performance and reliability.

Claims

1. A compressor unit comprising a base made in the form of a single frame with a drive pump mounted thereon, connected through a hydraulic distributor to a central hydraulic drive, inside which a piston with a double-sided rod is located, connected to oppositely arranged compression stage blocks, each of which includes a pneumatic cylinder with a piston and a compression chamber, characterized in that each pneumatic cylinder is equipped with a cooling jacket, and the compression chambers located in the compression stage blocks are made elongated, while the length of each compression chamber is from 10 to 15 mm.

2. A compressor unit according to paragraph 1, characterized in that the cooling jacket is made in the form of external and internal circuits adjacent to the pneumatic cylinder.

3. A compressor unit according to paragraph 1, characterized in that the cooling jacket is designed with the possibility of connection from the hydraulic drive drain.

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