WO2008122175A1

WO2008122175A1 - A stepped compressing method and system of a reciprocating piston compressor

Info

Publication number: WO2008122175A1
Application number: PCT/CN2007/070004
Authority: WO
Inventors: Chunsheng Jiang
Original assignee: Chunsheng Jiang
Priority date: 2007-04-10
Filing date: 2007-05-09
Publication date: 2008-10-16
Also published as: CN101285462A; CN101285462B

Abstract

A stepped compressing method and system of a reciprocating piston compressor has four-stage compressing output. Every stage has individual input and output tube line. Valves control the compressing stage, and a programmable logic controller (PLC) controls the valves. The output line of every stage is divided into two sub-lines, one of which is connected with the input line of the next stage compressing. A transducer controls the driving motor. The stepped compressing method and system greatly improves the compressing efficiency, saves cost and energy sources.

Description

Piston reciprocating compressor step compression method and system

Technical field

The present invention relates to a gas compression technique, and more particularly to a piston reciprocating compressor step compression method and system. Background technique

Piston reciprocating compressors are widely used in petroleum, natural gas and chemical industries. A common driving method for piston reciprocating compressors is motor drive. The rated output power of the motor is slightly larger than the input power required by the piston reciprocating compressor. The piston reciprocating compressor is usually operated according to the user's requirements. Under working conditions (inlet pressure, outlet pressure, gas flow, etc.), different series compression stages are designed. The higher the compression stage, the greater the motor output power required. For example, natural gas filling, when the natural gas inlet pressure is 0. 8Mpa, the outlet pressure of the filling tank after compression by the piston reciprocating compressor is 25 MPa, and the gas flow rate is 2220M7h. If the compression stage is continuously operated from the first stage to the fourth stage, the gas with an outlet pressure of 25 MPa is directly charged into the user's gas storage container, and the power consumed is 320 kW. Since the pressure in the tank is low at the beginning of the refueling of the user's gas tank, the four-stage compressor is used in series at the same time, and the gas is added to the gas tank at the highest pressure, which is undoubtedly a waste and will waste a lot of power. Consumption.

Summary of the invention

In order to compensate for the above deficiencies and reduce the power consumption of the piston reciprocating compressor, the present invention provides a piston reciprocating compressor step compression method and system.

The step compression method for the piston reciprocating compressor of the present invention comprises:

In the application of the coaxial multi-stage piston reciprocating compressor, each stage piston compressor is provided with a separate intake line and an outlet line, and the control system connected to the output line is connected to a series system capable of converting the compression system. ;

When the output pressure is less than 0.9 times the outlet rated pressure of the first stage of the piston reciprocating compressor, the first stage of the piston reciprocating compressor is directly output;

The piston reciprocating compressor is at a pressure of 0.9 times higher than the outlet rated pressure of the first stage of the piston reciprocating compressor, and the output pressure is 0.9 times higher than the outlet rated pressure of the first stage of the piston reciprocating compressor. The first stage and the second stage are connected in series, and are output by the second stage;

The piston reciprocating compressor is 9.0 times higher than the outlet rated pressure of the second stage of the piston reciprocating compressor, and the output pressure is 0.9 times higher than the outlet rated pressure of the second stage of the piston reciprocating compressor. The first stage, the second stage and the third stage are connected in series, and are outputted by the third stage;

When the output pressure is lower than the outlet rated pressure of the fourth stage of the piston reciprocating compressor and is higher than 0.9 times of the outlet rated pressure of the third stage of the piston reciprocating compressor, the first stage of the piston reciprocating compressor The second, third and fourth stages are connected in series, and are output by the fourth stage; The change of the series mode is controlled by the PLC. The PLC detects the pressure at each point through the pressure sensor, and switches the on/off of each valve according to the above pressure interval to form different series modes, and controls the drive motor through a frequency converter to determine the drive according to different series modes. The input power of the motor.

The piston reciprocating compressor step compression system of the invention comprises a piston reciprocating compressor and various input pipelines and output pipelines, pneumatic ball valves, electromagnetic reversing valves, coolers, gas-liquid separators, recovery tanks, pressure reducing valves, and drives The motor, the frequency converter, the PLC, the first-stage input pipeline is connected to the air inlet of the first-stage cylinder of the piston reciprocating compressor via an input pneumatic ball valve, and the first-stage output pipeline connected by the first-stage cylinder outlet port passes through the first-stage output pneumatic a ball valve is connected to the gas-liquid separator, and is connected to an intake port of the secondary cylinder of the piston reciprocating compressor via a primary branch pneumatic ball valve, and the secondary output line connected to the secondary cylinder outlet port passes through the secondary output a pneumatic ball valve is connected to the gas-liquid separator, and is connected to a gas inlet of a three-stage cylinder of the piston reciprocating compressor via a two-stage pneumatic ball valve, and the three-stage output pipeline connected to the three-stage cylinder air outlet passes through three stages An output pneumatic ball valve is connected to the gas-liquid separator, and a three-stage branch pneumatic ball valve is connected to an air inlet of the four-stage cylinder of the piston reciprocating compressor, The four-stage output line connected to the cylinder outlet is connected to the gas-liquid separator via a four-stage output pneumatic ball valve, and the main pressure sensor is respectively installed on the four output lines of the compressor, and all of the piston reciprocating compressor a common driving shaft of the cylinder, the driving motor is connected, the driving motor is connected to the frequency converter, and the input, output and branch pneumatic ball valves are respectively connected to a main electromagnetic reversing valve, the inverter, a main electromagnetic reversing valve and A main pressure sensor is connected to the PLC.

In the piston reciprocating compressor step compression system of the present invention, a one-way valve is connected in series to the connecting line between the output pneumatic ball valve and the gas-liquid separator.

In the piston reciprocating compressor step compression system of the present invention, the output line between the air outlet of each cylinder of the piston reciprocating compressor and the pneumatic ball valve is connected in series with a cooler and a filter, and a temperature sensor is connected in parallel.

In the piston reciprocating compressor step compression system of the present invention, on the first three stages of the filter, there is a road connection recovery pneumatic ball valve, and the three recovery pneumatic ball valves are connected to the recovery tank, and the recovery tank is connected through a return pressure reducing valve. The intake port of the first stage cylinder of the piston reciprocating compressor, and the three recovered pneumatic ball valves are respectively connected to the auxiliary electromagnetic reversing valve.

In the piston reciprocating compressor step compression system of the present invention, a branch line is connected to the primary cylinder output line of the piston reciprocating compressor, and is connected to all of the electromagnetic reversing valves by controlling a pressure reducing valve, the recovery tank There is also a branch line connecting all solenoid reversing valves.

The piston reciprocating compressor step compression system of the present invention has an input pressure sensor and an input pressure gauge on the inlet line of the inlet port and the input pneumatic ball valve, and an output pressure sensor is arranged on the gas-liquid separator and Output pressure gauge.

In the piston reciprocating compressor step compression system of the present invention, safety valves are installed on the four output lines, the gas-liquid separator and the recovery tank.

DRAWINGS Figure 1 is a schematic view of a step compression system of a piston reciprocating compressor of the present invention;

2 is an electrical connection diagram of a step compression system of a piston reciprocating compressor of the present invention.

detailed description

To further illustrate the stepped compression system of the piston reciprocating compressor of the present invention, a more detailed description will be given below in conjunction with the embodiments. The piston reciprocating compressor is changed from continuous power consumption of each stage to stepped power consumption. Since the piston reciprocating compressor consumes different amounts of power when compressing the gas, and is superimposed step by step according to the increase of the compression stage, the user's gas storage container is at different inflation pressures when reaching the required gas storage volume. At the point, the time required is different, and the power consumed by the piston reciprocating compressor is different when it is compressed to different inflation pressure points. Therefore, we have devised a new control method to change the piston reciprocating compressor from continuous power consumption to stepped power consumption.

The specific system is shown in Figure 1.

The system includes piston reciprocating compressor YS, pneumatic ball valve 4, B, C, electromagnetic reversing valve SV, cooler LQ, gas-liquid separator QYF, recovery tank PV, pressure reducing valve PR, safety valve SRV, check valve CV, pressure sensor PT, temperature sensor TS, drive motor, inverter, PLC;

The first input line connected to the air inlet port is connected to the air inlet of the first stage cylinder YS1 of the piston reciprocating compressor YS via the input pneumatic ball valve A1, and the first output line G1 connected to the air outlet of the first stage cylinder YS 1 is connected. Connected to the primary cooler LQ1 and the primary filter Fl, the primary filter F1 has one output through the primary output pneumatic ball valve B1 and a one-way valve CV1 connected to the gas-liquid separator QYF, the other branch through the primary branch The pneumatic ball valve A2 is connected to the intake port of the secondary cylinder of the piston reciprocating compressor, and is connected to the recovery tank PV via the first-stage recovery pneumatic ball valve C1; and connected to the primary output line G1 connected to the air outlet of the first-stage cylinder YS1. There is temperature sensor TS1, after the first cooler LQ1 is connected with safety valve SRV1, before the first-stage output pneumatic ball valve B1 is equipped with main pressure sensor PT11, before the primary branch pneumatic ball valve A2 is connected with pressure sensor PT12;

The secondary output line G2 connected to the outlet of the secondary cylinder YS2 is connected in series with the secondary cooler LQ2 and the secondary filter F2, and the secondary filter F2 has an output through the secondary output pneumatic ball valve B2 and a check valve CV2. Connecting the gas-liquid separator QYF, the other branch is connected to the intake port of the three-stage cylinder of the piston reciprocating compressor via the secondary branch pneumatic ball valve A3, and is connected to the recovery tank PV through the secondary recovery pneumatic ball valve C2; The secondary output line G2 connected to the outlet of the secondary cylinder YS2 is connected with a temperature sensor TS2, a safety valve SRV2 is connected after the secondary cooler LQ2, and a main pressure sensor PT21 is installed in front of the secondary output pneumatic ball valve B2. The pressure sensor PT22 is connected to the front side pneumatic ball valve A3;

The three-stage output line G3 connected to the outlet of the three-stage cylinder YS3 is connected in series with the three-stage cooler LQ3 and the third-stage filter F3, and the three-stage filter F3 has one output through the three-stage output pneumatic ball valve B3 and a one-way valve CV3. Connecting the gas-liquid separator QYF, the other branch is connected to the intake port of the four-stage cylinder of the piston reciprocating compressor through the three-stage branch pneumatic ball valve A4, and is connected to the recovery tank PV through the three-stage recovery pneumatic ball valve C3; The three-stage output line G3 connected to the air outlet of the three-stage cylinder YS3 is connected with the temperature sensor TS3, the safety valve SRV3 is connected after the third-stage cooler LQ3, and the main pressure is installed before the three-stage output pneumatic ball valve B3. Force sensor PT31, a pressure sensor ΡΤ32 is connected before the three-stage branch pneumatic ball valve Α4;

The four-stage output line G4 connected to the outlet of the four-stage cylinder YS4 is connected in series with the four-stage cooler LQ4 and the four-stage filter F4, and the four-stage filter F4 has one output through the four-stage output pneumatic ball valve Β4 and a one-way valve CV4. Connected to the gas-liquid separator QYF, the temperature sensor TS4 is connected to the fourth-stage output line G4 connected to the air outlet of the four-stage cylinder YS4, and the safety valve SRV4 and the bleed valve FQ1 are connected to the fourth-stage cooler LQ4. The main pressure sensor PT4 is installed in front of the output pneumatic ball valve B4.

All the pneumatic ball valves Al, Α2, A3, A4, Bl, Β2, Β3, Β4, Cl, C2, C3, have the pipeline and the electromagnetic reversing valve SV1-11 connected (the connection pair in this embodiment is: Al-SVll; A2-SV6; A3-SV4; A4-SV2; B1-SV10; B2-SV5; B3-SV3; B4-SV1; C1-SV8; C2-SV7; C3-SV9, but this is not the only way to connect The difference between the connection and the separate control can be), the recovery tank PV has a pipeline connecting all the electromagnetic reversing valves SV1—11, and the branch of the primary output line G1 is connected to all the electromagnetic reversing valves through a pressure reducing valve PR1 to provide pneumatic ball valve control. Use compressed gas.

The recovery tank PV is equipped with a pressure sensor PT6, a pressure gauge and a safety valve SRV6, and is connected to the input line via a pressure reducing valve PR2.

A pressure gauge can also be installed on the input line after the pneumatic ball valve A1 is input to the air inlet, and a pressure gauge can also be installed on the gas-liquid separator.

Gas-liquid separator QYF is connected to a safety valve SRV5, - Stage filter The road connected to F1 is also connected to a safety valve SRV0. Inverter, solenoid reversing valve SV1, SV2, SV3, SV4, SV5, SV6, SV10, SV11 and pressure sensor PT11, PT21, PT31, PT41 are connected to the PLC.

The different on-off states of the pneumatic ball valve change the working state of the system:

State 1: The first stage of the piston reciprocating compressor will take natural gas from P. =0.8 MPa compression to Pi<2.1=2.1X0.9=1.89 MPa,

A1, A3, A4, Bl, Cl, C2, C3 are valve open.

A2, B2, B3, B4 are valve closed.

At this time, the piston reciprocating compressor operates in the first stage. Until the user's gas storage container is charged to 1.89 MPa, the piston reciprocating compressor consumes <86 KW during this time period.

At MPa, the second stage of the piston reciprocating compressor begins to operate.

State 2: The second stage of the piston reciprocating compressor will take natural gas from? When 1.89 MPa is compressed to P ₂ <4.6=4.6X0.9=4.14 MPa,

A1, A2, A4, B2, C2, C3 are valve open states.

A3, B1, B3, B4, CI are valve closed. At this time, the piston reciprocating compressor operates in the second stage. Until the user's gas storage container is charged to 4. 14 MPa, the piston reciprocating compressor consumes < 160 KW during this time period. When P ₂ 4. 14 MPa, the third stage of the piston reciprocating compressor starts to operate.

State 3: The third stage of the piston reciprocating compressor compresses the natural gas from P ₂ =4.14 MPa to P ₃ < 12. 3=12. 3X0. 9=11. 07 MPa,

Al, A2, A3, B3, C3 are valve open.

A4, B1, B2, B4, Cl, C2 are valve closed.

At this time, the piston reciprocating compressor is operated in the second stage, the second stage, and the third stage. Until the user's gas storage container is charged to 11.07 MPa, the piston reciprocating compressor consumes power during this period. 251 KW. When P ₃ 11.07 MPa, the fourth stage of the piston reciprocating compressor starts to operate.

State 4: The fourth stage of the piston reciprocating compressor compresses the natural gas from P3=l l. 07 MPa to P4=25X0. 9=22. 5 MPa,

A1, A2, A3, A4, B4, are valve open.

B1, B2, B3, C1, C2, and C3 are valve closed states.

At this time, the second stage, the second stage, the third stage, and the fourth stage of the piston reciprocating compressor are continuously operated until the user's gas storage container is charged to 22.5 MPa, at this time, the piston reciprocating Compressor power consumption <320 KW.

Industrial applicability

The piston reciprocating compressor step compression system of the present invention is applied to the natural gas filling tank car gas tank. The invention can effectively reduce the electric energy required for the filling process by 36%, specifically:

When the first stage of the piston reciprocating compressor compresses natural gas from 0.8 MPa to 2. 1X0. 9=1. 89 MPa, when the user's gas storage container reaches 1.89 MPa, it is converted to two-stage compression. During this time period, the piston reciprocating compressor consumes < 86 KW.

When the second stage of the piston reciprocating compressor compresses the natural gas from 1.89 MPa to 4. 6X0. 9=4. 14 MPa, when the user's gas storage container reaches 4.14MPa, it is converted to the third-stage compression. During the time period, the piston reciprocating compressor consumes < 160 KW.

When the third stage of the piston reciprocating compressor compresses the natural gas from 4. 14 MPa to 12. 3X0. 9=11. 07 MPa, when the user's gas storage container reaches 11.07 MPa, it is converted to four-stage compression. During the time period, the piston reciprocating compressor consumes <251 KW. When the fourth stage of the piston reciprocating compressor compresses the natural gas from 11.07 MPa to 25×0. 9=22. 5MPa, when the user's gas storage container reaches 22. 5MPa, during this period, the piston reciprocating compressor consumes Power <320 KW.

We still superimpose the power consumed by the compression of the piston reciprocating compressor on the power divided by four to get the average power consumption (86+160+251+322) /4=205 KW.

From this we can calculate that stepwise than continuous can save 1- (205/320) = 36% energy consumption.

The above four states are controlled by the inverter to control the motor in different working states and output different powers. The electronic control system uses a PLC (Programmable Logic Controller) to control each operation of the piston reciprocating compressor. The device uses a variety of sensors, transmitters, solenoid valves to control and detect the operation of the equipment, as well as safety shutdown and fault alarms in the event of abnormal operation or failure, the operating status can be displayed in real time on the panel of the control cabinet On the tube, the touch screen of the full Chinese interface provides users with two easy-to-operate and friendly platforms that can be unattended.

The step compression system of the piston reciprocating compressor of the invention can be applied not only to natural gas tanker cans, but also to other similar compressed tanks of air, petroleum gas, simple gas (such as oxygen, nitrogen, etc.), and consumes The power consumption is reduced by 36% compared with the traditional continuous type. It is of great significance for the piston reciprocating compressor users to reduce operating expenses, energy saving and consumption reduction, which fully conforms to the current development trend of building an energy-saving society.

Claims

Rights request

1. A step compression method for a piston reciprocating compressor, characterized in that:

In the application of a coaxial multi-stage piston reciprocating compressor, each stage piston compressor is provided with a separate input line and an output line, and is connected to a series-convertible compression system through the control of the valve on the output input line;

When the output pressure is lower than the outlet rated pressure of the fourth stage of the piston reciprocating compressor and is higher than 0.9 times of the outlet rated pressure of the third stage of the piston reciprocating compressor, the first stage of the piston reciprocating compressor The second, third and fourth stages are connected in series, and are output by the fourth stage;

The change of the series mode is controlled by the PLC. The PLC detects the pressure of each point through the pressure sensor, changes the on/off of each valve according to the above interval, forms different series mode, and controls the drive motor through a frequency converter to determine the drive motor according to different series modes. Input power.

2. Stepped compression system for piston reciprocating compressor, including piston reciprocating compressor (YS) and input and output lines (G), pneumatic ball valves (A, B, C), electromagnetic reversing valve (SV), cooling (LQ), gas-liquid separator (QYF), recovery tank (PV), pressure reducing valve (PR), drive motor, frequency converter, PLC, characterized in that the primary input line is connected via the input pneumatic ball valve (A1) An intake port of a primary cylinder (YS1) of the piston reciprocating compressor (YS), the first stage cylinder

(YS1) The primary output line (G1) connected to the air outlet is connected to the gas-liquid separator (QYF) via a primary output pneumatic ball valve (B1), and the piston is reciprocated via a primary branch pneumatic ball valve (A2) An intake port of a secondary cylinder (YS2) of a compressor (YS), a secondary output line (G2) connected to an outlet of the secondary cylinder (YS2) is connected to the gas-liquid via a secondary output pneumatic ball valve (B2) a separator (QYF) connected to an intake port of a three-stage cylinder (YS3) of the piston reciprocating compressor (YS) via a secondary branch pneumatic ball valve (A3), and the three-stage cylinder (YS3) air outlet connection The three-stage output line (G3) is connected to the gas-liquid separator (QYF) through a three-stage output pneumatic ball valve (B3), and is connected to the piston reciprocating compressor (YS) via a three-stage branch pneumatic ball valve (A4). The inlet of the four-stage cylinder (YS4), the outlet of the four-stage cylinder (YS4) The four-stage output line (G4) is connected to the gas-liquid separator (QYF) via a four-stage output pneumatic ball valve (B4); the main output is installed on the four output lines (Gl, G2, G3, G4) of the compressor a pressure sensor (PT11, ΡΤ21, ΡΤ31, ΡΤ4), a common drive shaft of all the cylinders of the piston reciprocating compressor, connected to the drive motor, the drive motor is connected to the inverter, the input, the output and the branch Pneumatic ball valves (Al, Α2, A3, A4, Bl, Β2, Β3, Β4) are respectively connected to the main electromagnetic directional control valves (SV11, SV6, SV4, SV2, SV10, SV5, SV3, SV1), the inverter, the main Electromagnetic directional valves (SV11, SV6, SV4, SV2, SV10, SV5, SV3, SV1) and main pressure sensors (PT11, ΡΤ21, ΡΤ31, ΡΤ4) are connected to the PLC.

A stepped compression system for a piston reciprocating compressor according to claim 2, wherein a connection line between said output pneumatic ball valve (B1, B2, B3, B4) and a gas-liquid separator (QYF) is provided. Connect a check valve (CV1, CV2, CV3, CV4) in series.

4. The piston reciprocating compressor step compression system according to claim 3, wherein an output line between the air outlet of each cylinder of the piston reciprocating compressor (YS) and the output pneumatic ball valve (Gl, G2, G3, G4) are connected in series with the cooler (LQU LQ2, LQ3, LQ4) and the filter (Fl, F2, F3, F4), and a temperature sensor (TS1, TS2, TS3, TS4) is connected in parallel.

5. The piston reciprocating compressor step compression system according to claim 4, characterized in that, in the first three stages of filters (Fl, F2, F3), there is a road connection to recover the pneumatic ball valves (Cl, C2, respectively). C3), the three recovery pneumatic ball valves (Cl, C2, C3) are connected to a recovery tank (PV), and the recovery tank (PV) is connected to the piston reciprocating compressor via a reflux pressure reducing valve (PR2) ( YS) - the primary intake line of the stage cylinder (YS1); the three recovery pneumatic ball valves (Cl, C2, C3) are respectively connected to the auxiliary electromagnetic reversing valves (SV8, SV7, SV9).

6. The piston reciprocating compressor step compression system according to claim 5, wherein a branch line is connected to the primary cylinder (YS1) output line (G1) of the piston reciprocating compressor (YS) Connected to all of the electromagnetic reversing valves (SV1-11) by a control pressure reducing valve (PR1), which also has a branch line connecting all the electromagnetic reversing valves (SV1-11).

7. The piston reciprocating compressor step compression system according to claim 6, wherein an input pressure sensor (PT0) is connected in parallel to the intake port and the input line after the input pneumatic ball valve (A1). And an input pressure gauge, an output pressure sensor (PT5) and an output pressure gauge are mounted on the gas-liquid separator (QYF).

8. The piston reciprocating compressor step compression system according to claim 7, wherein said four output lines (Gl, G2, G3, G4), a gas-liquid separator (QYF), and a recovery tank Safety valves (SRV1, SRV2, SRV3, SRV4, SRV5, SRV6) are installed on (PV).