One-button starting system and starting method of multi-stage reciprocating compressor

Abstract

The present invention relates to the field of offshore oil and gas extraction technology, and more specifically, to a one-button start system for a multi-stage reciprocating compressor and a method for starting the system. The one-button start system comprises a controller, a one-button start control unit, a positive pressure ventilation and fire and gas system detection unit, an external auxiliary system detection unit, an alarm unit, and a signal acquisition unit. The present invention overcomes the disadvantage of the prior art that multi-stage reciprocating compressors cannot be started with one button. By integrating the entire startup process of the multi-stage reciprocating compressor through sequential control, a highly automated, safe, and efficient startup solution is formed, which avoids the safety risks of manual startup, saves manpower, reduces labor costs, and also improves the production and operation efficiency of offshore oil and gas extraction platforms.

Description

Technical Field

[0001] The present invention relates to the technical field of marine oil and gas exploitation, and more particularly to a one-button starting system for a multi-stage reciprocating compressor and a starting method thereof. Background Art

[0002] Compressors are key equipment for natural gas boosting in the field of offshore oil and gas extraction. They are mainly divided into centrifugal compressors, screw compressors and reciprocating compressors. Among them, reciprocating compressors include single-stage compressors and multi-stage compressors. Multi-stage compressors adopt a multi-stage compression method. With multi-stage compression, an intercooler can be set between the stages to make the compressed gas undergo isobaric cooling after the first stage of compression to reduce the temperature before entering the next stage of cylinder compression. Compared with single-stage compression, it saves more power and reduces the temperature of the final exhaust gas. Therefore, multi-stage reciprocating compressors are often used in offshore oil and gas extraction. At present, the multi-stage reciprocating compressor skids on offshore platforms use imported core components and select domestic accessories to assemble them into skids, including control cabinet positive pressure ventilation system, fire and gas system, lubrication system, oil injection system, instrument air system, control system, multi-stage compressor unit, natural gas cooling system and gas-liquid separation tank. The entire compressor structure is complex and large in size. There are the following problems in starting the compressor:

[0003] (1) The key equipment of existing reciprocating compressors is provided by different manufacturers, and the control system, auxiliary system and starting system are independent of each other, lacking effective sequential control connection and interlocking protection;

[0004] (2) Starting the compressor requires high-quality staff and carries the risk of misoperation. It also requires multiple staff to cooperate and check each system one by one, and then manually start the relevant systems in sequence before the compressor can be started. The entire startup process is time-consuming and labor-intensive, resulting in low startup efficiency.

[0005] (3) During the start-up of the compressor, workers need to adjust the relevant equipment several times. These devices are located around the rotating parts, which may cause casualties to the workers.

[0006] (4) The development of offshore oil and gas production platforms is gradually tending towards unmanned, less-manned and intelligent operations. Currently, the startup automation level of multi-stage reciprocating compressors is low and cannot meet the development needs. Summary of the Invention

[0007] In response to the problem in the above-mentioned prior art that multi-stage reciprocating compressors cannot be started with one button, the present invention provides a multi-stage reciprocating compressor one-button start system and a start method thereof, which can realize the automation of the adjustment of each system, avoid manual operation errors, and improve the compressor start-up efficiency.

[0008] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0009] A one-button starting system for a multi-stage reciprocating compressor, comprising:

[0010] A controller; an alarm unit electrically connected to the controller, for sounding an alarm; a one-button start control unit, including a start button; a positive pressure ventilation and fire and gas system detection unit, including an air pressure transmitter, a combustible gas probe and a flame probe electrically connected to the controller, for detecting whether the pressure of the positive pressure ventilation hood is within the explosion-proof pressure range, and for detecting whether there is a fire or combustible gas leak in the compressor fire and gas system; an external auxiliary system detection unit, including an instrument air pressure transmitter and a cooling water pressure transmitter electrically connected to the controller respectively, for detecting whether the instrument air supply pressure of the compressor and the cooling water pressure of the compressor are normal; a signal acquisition unit electrically connected to the controller, the combustible gas probe, the flame probe, the positioners of the valves in the compressor unit, the transmitters and the frequency converters are electrically connected to the signal acquisition unit respectively.

[0011] In the above technical solution, after the start button is pressed, the controller receives the start signal, and the positive pressure ventilation and fire and gas system detection unit starts detection. After the detection is passed, the controller controls the external auxiliary system detection unit to perform detection. After the detection is passed, the transmitters in the compressor unit transmit the signal to the controller. At the same time, the signal acquisition unit collects the signals of the positioners, transmitters and inverters on the valves in the compressor unit and transmits the signal to the controller. The controller makes a judgment based on the signal. If the signal is normal, the compressor pre-lubrication oil pump is controlled to pre-lubricate the compressor unit. After the pre-lubrication is completed, the compressor main motor is controlled to start. After the main motor is started, manual adjustment is made or the controller automatically adjusts the load of each level of the compressor to balance. The unit runs stably and the compressor is started with one button. During the entire startup process, if the controller determines that a signal is not within the normal range, the currently executed step is exited. The controller controls the alarm unit to sound an alarm or shut down the compressor main motor according to the signal situation. After the staff makes corresponding adjustments, they re-enter the one-button start program.

[0012] Preferably, the system also includes an air booster unit connected to the compressor instrument air supply pipeline and a cooling water booster pump connected to the compressor cooling water pipeline, so as to increase the instrument air supply pressure and cooling water pressure, ensuring that the instrument air pressure is sufficient to open each air valve and the cooling water pressure is sufficient to enable the compressor unit to dissipate heat normally.

[0013] Preferably, the system further comprises a lubricating oil heater for heating the lubricating oil in the crankcase of the compressor, wherein the lubricating oil heater is electrically connected to the controller. By heating the lubricating oil in the crankcase, the warm-up time of the compressor is reduced.

[0014] The present invention also provides a one-button starting method for a multi-stage reciprocating compressor, which is applied to the above-mentioned one-button starting system for a multi-stage reciprocating compressor, comprising:

[0015] Step S1: Start the one-button start control unit and proceed to step S2;

[0016] Step S2: positive pressure ventilation and fire and gas system detection, the air pressure transmitter transmits a signal to the controller, the combustible gas probe and the flame probe transmit a signal to the signal acquisition unit, the signal acquisition unit transmits a signal to the controller, the controller determines whether the signal meets the startup conditions, if so, proceeds to step S3, if not, the controller controls the alarm unit to sound an alarm and exits step S2;

[0017] Step S3: External auxiliary system detection: the instrument air pressure transmitter and the cooling water pressure transmitter transmit signals to the controller, and the controller determines whether the signals meet the startup conditions. If so, the process proceeds to step S4. If not, the controller controls the alarm unit to sound an alarm, readjusts the compressor instrument air supply pressure and the compressor cooling water pressure to normal, and then re-enters step S3.

[0018] Step S4: The internal electrical instrument system of the unit is tested. The signal acquisition unit collects the signals of the valve positioners, transmitters and inverters of each valve in the compressor and transmits the signals to the controller. The controller determines whether the status of each valve, transmitter and inverter meets the startup conditions based on the signals. If so, the process proceeds to step S5. If not, the controller controls the alarm unit to sound an alarm and exits step S4.

[0019] Step S5: System purge, the controller controls the purge valve and vent valve in the compressor unit to purge the compressor unit working chamber, compressor process pipeline and return pipeline. After the set purge time, the controller controls the pressure charging valve and vent valve in the compressor unit to pressurize the compressor unit working chamber to the set pressure and then enters step S6;

[0020] Step S6: The compressor unit is pre-lubricated. The liquid level transmitter in the compressor crankcase and the hydraulic pressure transmitter at the oil outlet of the compressor pre-lubricating oil pump transmit signals to the controller. The controller determines whether the lubricating oil level in the crankcase and the lubricating oil pressure pumped out by the pre-lubricating oil pump are qualified. If so, the controller enters step S7 after a preset lubrication time. If not, the controller controls the alarm unit to sound an alarm. After adjusting to qualified conditions, the controller re-enters step S6.

[0021] Step S7: Start the main motor of the compressor. The speed transmitter on the main motor of the compressor and the hydraulic pressure transmitter at the oil outlet of the main lubricating oil pump transmit signals to the controller. The controller determines whether the speed of the main motor of the compressor and the pressure of the lubricating oil pumped out by the main lubricating oil pump are within the normal range. If so, the process proceeds to step S8. If not, the controller controls the alarm unit to sound an alarm and controls the compressor unit to shut down. After adjusting to normal, the process re-enters step S6.

[0022] Step S8: The controller controls the valve positioners of the compressor to control the opening and closing of the valves to adjust the loads of the compressor at each level. After the adjustment is completed, the controller determines whether the pressure signals, liquid level signals, vibration signals, and temperature signals in the compressor unit are all within the normal range. If so, the controller proceeds to step S9. If not, the controller controls the alarm unit to sound an alarm and control the compressor unit to shut down, and exits step S8.

[0023] Step S9: The compressor one-button start is completed.

[0024] Preferably, in step S1, before starting the one-button start control unit, it is first confirmed that the upstream and downstream process flows of the compressor meet the start-up conditions, that is, the upstream production well of the compressor has been opened, the upstream and downstream processing equipment of the compressor has been put into use, and the subsea pipeline has been ready for external transmission. Then, it is confirmed that the internal process flow of the compressor and the manual valves of the auxiliary system meet the start-up conditions, that is, the high-pressure safety valve, low-pressure safety valve and return valve of the internal process flow of the compressor are all in the open state, the cooling water circuit and the lubricating oil circuit are in the conducting state, and the manual valves at each discharge point and the waste oil discharge point are all in the closed state.

[0025] Preferably, in step S2, before detecting the pressure of the positive pressure fume hood cabinet, the air inlet valve of the control cabinet is opened to ventilate the control cabinet for 4 to 6 minutes. Since there may be flammable and explosive gases or water vapor in the control cabinet at the beginning, it is necessary to replace these flammable and explosive gases and water vapor by inputting clean gas, and ventilating for 4 to 6 minutes can ensure that the clean gas replaces all the gas in the control cabinet cabinet out of the cabinet.

[0026] Preferably, in step S3, if the air supply pressure of the compressor instrument air system is insufficient and remains insufficient after adjusting the valves, the standby air compressor unit is activated to increase the pressure of the instrument air. If the compressor cooling water pressure is insufficient and remains insufficient after adjusting the valves, the standby cooling water booster pump is activated to increase the pressure of the cooling water. The instrument air supply pressure is the power source for opening the valves of the compressor unit. If the instrument air supply pressure is insufficient, the pneumatic valves in the compressor cannot open and the compressor cannot operate normally. Therefore, the instrument air supply pressure must be guaranteed to be qualified. Insufficient cooling water pressure will lead to poor heat dissipation of the compressor, which may cause safety accidents. Therefore, it is necessary to ensure that the cooling water reaches normal pressure.

[0027] Preferably, in step S4, the specific process of detecting whether the status of each valve, each transmitter and each inverter meets the startup conditions is that the controller controls the action of each valve according to the set opening values ​​of 0, 25%, 50%, 75% and 100% respectively, and the positioner on each valve detects the actual opening information of each valve and transmits the information to the controller, and the controller then determines whether the status of each valve is consistent with the setting. If so, it means that each valve meets the startup conditions; if the controller can receive signals from each transmitter and each inverter, it means that each transmitter and each inverter are online and meet the startup conditions.

[0028] Preferably, in step S5, the specific process of system purge is that the controller controls the purge valve and the vent valve in the compressor unit to open simultaneously, purge the working chamber of the compressor unit, the compressor process pipeline and the return pipeline, and purge the condensate and debris. After each purge for 80 to 100 seconds, the charging valve is opened and the vent valve is closed to pressurize the working chamber of the compressor unit. After the compressor unit reaches the starting pressure of 600 to 800 kPa, the controller controls the closing of the purge valve and the charging valve.

[0029] Preferably, in step S7, 8 to 12 seconds after the pre-lubricating oil pump is started, the controller starts to determine whether the lubricating oil level signal in the crankcase and the lubricating oil pressure pumped out by the pre-lubricating oil pump are qualified. A stable lubricating oil pressure has been established 8 to 12 seconds after the pre-lubricating oil pump is started, thereby preventing misjudgment.

[0030] The beneficial effects of the present invention are as follows: the entire startup process of a multi-stage reciprocating compressor is sequentially integrated to form a startup solution with a high degree of automation, safety and efficiency, thereby avoiding the safety risks in the manual startup process, saving manpower, reducing employment costs, and also improving the production and operation efficiency of offshore oil and gas production platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a principle flow chart of a one-button start system for a multi-stage reciprocating compressor;

[0032] Figure 2 It is a flow chart of a one-button starting method for a multi-stage reciprocating compressor;

[0033] Figure 3 This is a flow chart of the positive pressure fume hood cabinet pressure detection in step S3. DETAILED DESCRIPTION

[0034] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. It should be noted that the following embodiments are used to illustrate the present invention but are not intended to limit the scope of use of the present invention.

[0035] At the same time, the description of the following exemplary embodiments is actually only illustrative and does not constitute any limitation on the application of the technical solution of the present invention. The technical solutions and startup methods and equipment known to technicians in the relevant fields are not discussed in detail. However, in certain special cases, the technical solutions, equipment methods should be regarded as part of the authorization specification.

[0036] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0037] Example 1

[0038] like Figure 1 A multi-stage reciprocating compressor one-button start system is shown, comprising:

[0039] Controller; an alarm unit electrically connected to the controller, used to issue an alarm; a one-button start control unit, including a start button and a digital input card; a positive pressure ventilation and fire and gas system detection unit, including an air pressure transmitter, a combustible gas probe and a flame probe electrically connected to the controller, used to detect whether the pressure of the positive pressure ventilation hood is within the explosion-proof pressure range, and used to detect whether there is a fire or combustible gas leak in the compressor fire and gas system; an external auxiliary system detection unit, including an instrument air pressure transmitter and a cooling water pressure transmitter electrically connected to the controller respectively, used to detect whether the instrument air supply pressure of the compressor and the cooling water pressure of the compressor are normal; a signal acquisition unit electrically connected to the controller, and the combustible gas probe, the flame probe, the positioners of the valves in the compressor unit, the transmitters and the frequency converters are electrically connected to the signal acquisition unit respectively.

[0040] Specifically, the controller is a PLC controller, the start button is set on the compressor LCP control panel, and a human-machine interface is also established on the compressor LCP control panel.

[0041] Furthermore, the system also includes an air booster unit connected to the compressor instrument air supply pipeline and a cooling water booster pump connected to the compressor cooling water pipeline, thereby increasing the instrument air supply pressure and cooling water pressure, ensuring that the instrument air pressure is sufficient to open each air valve and the cooling water pressure is sufficient to enable the compressor unit to dissipate heat normally.

[0042] Furthermore, the system also includes a lubricating oil heater for heating the lubricating oil in the crankcase of the compressor, the lubricating oil heater being electrically connected to the controller. By heating the lubricating oil in the crankcase, the warm-up time of the compressor is reduced.

[0043] The working principle or workflow of this embodiment is as follows: Pressing the start button transmits a digital signal to the digital input card. The digital input card converts the digital signal into a signal recognizable by the controller and transmits it to the controller. After the controller receives the start signal from the digital input card, the positive pressure ventilation and fire and gas system detection unit begins detection. If the detection passes, the controller controls the external auxiliary system detection unit to conduct detection. After the detection passes, the transmitters in the compressor unit transmit signals to the controller. Simultaneously, the signal acquisition unit collects signals from the positioners, transmitters, and inverters on the valves in the compressor unit and transmits the signals to the controller. The controller makes a judgment based on the signals. If the signals are normal, the compressor pre-lubrication oil pump is controlled to pre-lubricate the compressor unit. After pre-lubrication is completed, the compressor main motor is controlled to start. After the main motor starts, manual adjustment or automatic adjustment by the controller to balance the load of each level of the compressor is performed, and the unit operates stably, completing the one-button start of the compressor. During the entire startup process, if the controller determines that a signal is not within the normal range, the currently executed step is exited. The controller controls the alarm unit to sound an alarm or shut down the compressor main motor based on the signal condition. After the staff makes corresponding adjustments, the one-button start procedure is re-entered.

[0044] The beneficial effects of this embodiment are as follows: the entire startup process of a multi-stage reciprocating compressor is sequentially integrated to form a highly automated, safe and efficient startup solution, thereby avoiding the safety risks during manual startup, saving manpower, reducing labor costs, and improving the production and operation efficiency of offshore oil and gas production platforms.

[0045] Example 2

[0046] A one-button starting method for a multi-stage reciprocating compressor, applied to the one-button starting system for a multi-stage reciprocating compressor of Example 1, comprises:

[0047] Step S1: Start the one-button start control unit and proceed to step S2;

[0048] Step S2: Positive pressure ventilation and fire and gas system detection: the air pressure transmitter transmits a signal to the controller, the combustible gas probe and the flame probe transmit a signal to the signal acquisition unit, and the signal acquisition unit transmits the signal to the controller. The controller determines whether the signal meets the startup conditions. If so, it proceeds to step S3. If not, the controller controls the alarm unit to sound an alarm and exits step S2.

[0049] Step S3: External auxiliary system detection: The instrument air pressure transmitter and the cooling water pressure transmitter transmit signals to the controller. The controller determines whether the signals meet the startup conditions. If so, the process proceeds to step S4. If not, the controller controls the alarm unit to sound an alarm, readjusts the compressor instrument air supply pressure and the compressor cooling water pressure to normal, and then re-enters step S3.

[0050] Step S4: The unit's internal electrical instrument system detects signals from the valve positioners, transmitters, and inverters of each valve in the compressor, and transmits the signals to the controller. The controller determines whether the status of each valve, transmitter, and inverter meets the startup conditions based on the signals. If so, the process proceeds to step S5. If not, the controller controls the alarm unit to sound an alarm and exits step S4.

[0051] Step S5: System purging: The controller controls the purge valve and vent valve in the compressor unit to purge the working chamber, process pipeline and return pipeline of the compressor unit. After the set purge time, the controller controls the charge valve and vent valve in the compressor unit to charge the working chamber of the compressor unit to the set pressure, and then enters step S6;

[0052] Step S6: The compressor unit is pre-lubricated. The liquid level transmitter in the compressor crankcase and the hydraulic pressure transmitter at the oil outlet of the compressor pre-lubricating oil pump transmit signals to the controller. The controller determines whether the lubricating oil level in the crankcase and the lubricating oil pressure pumped out by the pre-lubricating oil pump are qualified. If so, the controller enters step S7 after the preset lubrication time. If not, the controller controls the alarm unit to sound an alarm. After adjusting to qualified conditions, the controller re-enters step S6.

[0053] Step S7: Start the main motor of the compressor. The speed transmitter on the main motor of the compressor and the hydraulic pressure transmitter at the oil outlet of the main lubricating oil pump transmit signals to the controller. The controller determines whether the speed of the main motor of the compressor and the pressure of the lubricating oil pumped out by the main lubricating oil pump are within the normal range. If so, the process proceeds to step S8. If not, the controller controls the alarm unit to sound an alarm and control the compressor unit to shut down. After adjusting to normal, the process re-enters step S6.

[0054] Step S8: The controller controls the valve positioners of the compressor to control the opening and closing of the valves to adjust the loads of the compressor at each level. After the adjustment is completed, the controller determines whether the pressure signals, liquid level signals, vibration signals, and temperature signals in the compressor unit are all within the normal range. If so, the controller proceeds to step S9. If not, the controller controls the alarm unit to sound an alarm and control the compressor unit to shut down, and exits step S8.

[0055] Step S9: The compressor one-button start is completed.

[0056] The implementation process of this embodiment is as follows Figure 2 shown.

[0057] The beneficial effects of this embodiment are consistent with those of embodiment 1.

[0058] Example 3

[0059] This embodiment further defines the steps based on Example 2. Before activating the one-button start control unit, it is first confirmed that the upstream and downstream process flows of the compressor meet the startup conditions, namely, the upstream production well of the compressor has been drilled, the upstream and downstream processing equipment of the compressor has been put into use, and the offshore pipeline is ready for external transmission. It is then confirmed that the internal process flow of the compressor and the manual valves of the auxiliary system meet the startup conditions, namely, the high-pressure safety valve, low-pressure safety valve, and return valve of the internal process flow of the compressor are all open, the cooling water circuit and lubricating oil circuit are in a conducting state, and the manual valves at the various drain points and waste oil discharge points are all closed.

[0060] In step S2, the specific process is as follows Figure 3 As shown, first open the control cabinet air inlet valve, and power on the positive pressure fume hood. Manually open the positive pressure fume hood's regulating filter pressure reducing valve and precision pressure reducing valve. The instrument air passes through the filter pressure reducing valve, precision pressure reducing valve and control cabinet air inlet valve into the control cabinet, and ventilate the control cabinet for 5 minutes. Since there may be flammable and explosive gases or water vapor in the control cabinet at the beginning, it is necessary to replace these flammable and explosive gases and water vapor by inputting clean gas. Ventilating for 5 minutes can ensure that the clean gas replaces all the gases in the control cabinet out of the cabinet. After the ventilation is completed, the air pressure transmitter in the positive pressure fume hood transmits the detected air pressure signal to the controller. The controller then determines whether the air pressure of the positive pressure fume hood is qualified. If qualified, it continues to the next step. If unqualified, the alarm unit is controlled to sound an alarm and exit the current step. After manual adjustment, it re-enters the step.

[0061] Furthermore, step S2 also includes bursting membrane status detection. The signal acquisition unit collects the status signal of the bursting membrane of the compressor fire and gas system and transmits the signal to the controller. When a natural gas leak occurs, the bursting membrane ruptures. At this time, the bursting membrane circuit cannot transmit the electrical signal to the controller, and the controller exits the positive pressure fume hood and fire and gas system detection steps. The staff makes corresponding adjustments and then re-enters step S2.

[0062] In step S3, if the instrument air pressure transmitter detects that the compressor's instrument air system supply pressure is less than 800 kPa and remains insufficient after adjusting the valves, the standby air compressor unit is manually activated to boost the instrument air pressure. If the compressor's cooling water pressure is less than 600 kPa and remains insufficient after manually adjusting the valves, the standby cooling water booster pump is manually activated to boost the cooling water pressure. The instrument air supply pressure is the power source for opening the valves in the compressor unit. If the instrument air supply pressure is insufficient, the pneumatic valves in the compressor cannot open, and the compressor cannot operate normally. Therefore, the instrument air supply pressure must be guaranteed to be qualified. Insufficient cooling water pressure can lead to poor heat dissipation in the compressor and affect the operation of the compressor unit, so the cooling water must be ensured to reach normal pressure.

[0063] In step S4, the specific process of detecting whether the status of each valve, each transmitter and each inverter meets the startup conditions is that the controller controls the action of each valve according to the set opening values ​​of 0, 25%, 50%, 75% and 100% respectively, and the positioner on each valve detects the actual opening information of each valve and transmits the information to the controller. The controller then determines whether the status of each valve is consistent with the setting. If so, it means that each valve meets the startup conditions; if the controller can receive signals from each transmitter and each inverter, it means that each transmitter and each inverter are online and meet the startup conditions; if one of the conditions is not met, the current step is exited, the controller controls the alarm unit to sound an alarm, and then re-enters step S4 after manual inspection and adjustment.

[0064] In step S5, the specific process of system purge is that the controller controls the purge valve and the vent valve in the compressor unit to open at the same time, purge the working chamber of the compressor unit, the compressor process pipeline and the return pipeline, and blow away the condensate and debris. After 90 seconds of purge, the charging valve is opened and the vent valve is closed to pressurize the working chamber of the compressor unit. After the working chamber of the compressor unit reaches the starting pressure of 700KPa, the controller controls the closing of the purge valve and the charging valve to ensure that the compressor can discharge air normally, to prevent the gas from being repeatedly compressed in the working chamber due to insufficient starting pressure, causing the exhaust temperature to rise, and finally damaging the outlet valve.

[0065] In step S6, the liquid level transmitter in the high-level oil tank of the compressor transmits the liquid level signal to the controller, and at the same time, the liquid level transmitter in the crankcase of the compressor transmits the liquid level signal to the controller. The controller determines that the liquid level in the high-level oil tank reaches above one-third of the liquid level and the liquid level in the crankcase is between one-third and two-thirds of the liquid level. The controller then controls the pre-lubricating oil pump to start; 10 seconds after the pre-lubricating oil pump is started, the controller determines whether the lubricating oil pressure pumped out by the pre-lubricating oil pump is greater than 300KPa. If the lubricating oil pressure is greater than 300KPa, the controller starts the pre-lubricating oil pump. This indicates that the lubricating oil pressure is qualified, and then pre-lubrication is performed for 120 seconds. During this process, if the lubricating oil temperature transmitter detects that the lubricating oil pressure is less than 40°C, the controller controls the lubricating oil heater in the crankcase to start, and heats the lubricating oil in the crankcase to 40°C, thereby reducing the warm-up time of the compressor; if the lubricating oil pressure pumped out by the pre-lubricating oil pump is less than 300KPa, the controller controls the pre-lubricating oil pump to shut down, and at the same time controls the alarm unit to sound an alarm and exit step S6. The staff checks and adjusts the compressor lubrication system before re-entering step S8.

[0066] In step S7, after the pre-lubrication is completed, the controller controls the main lubricating oil pump to start, increases the lubricating oil pressure to 375KPa, and keeps it for 10 seconds before controlling the pre-lubricating oil pump to shut down; then the controller controls all the return valves in the compressor unit to open, and the main motor inverter adjusts the starting power of the main motor to 30HZ, and the controller then controls the main motor speed to increase slowly.

[0067] In step S8, the load adjustment mode of each stage of the compressor includes a manual adjustment mode and an automatic adjustment mode. The specific process of manual adjustment is that the pressure difference information before and after the inlet loading valve of each stage of the compressor is sent to the controller through the signal acquisition unit, and the controller determines whether the pressure difference is qualified. If it is lower than the qualified range, the alarm unit is controlled to sound an alarm, and the staff manually reduces the opening of the return valve, and then adjusts the main motor speed to redistribute the pressure of each stage of the compressor to ensure that each stage can play a role in compressing gas; the specific process of the automatic adjustment mode is that the pressure difference information before and after the inlet loading valve of each stage of the compressor is sent to the controller through the signal acquisition unit, and the controller determines whether the pressure difference is lower than the qualified range. If it is lower than the qualified range, the controller controls the return valve opening to decrease, and adjusts the main motor speed at the same time until the load distribution of each stage is reasonable; if it is found that the air intake in the compressor chamber is insufficient during the process of adjusting the load at each stage, the controller controls the main motor speed to be reduced to the minimum rated speed, and then controls the adjustment of the return valve opening until the load distribution of each stage is reasonable.

[0068] It is understandable that after the compressor is running stably, the controller can choose to control the alarm unit to sound an alarm or shut down the compressor main motor according to the size of the signal. Each time the alarm unit sounds an alarm, an alarm record is made on the compressor LCP control panel.

[0069] It is understandable that the shutdown methods after the compressor is successfully started can be divided into normal shutdown, emergency shutdown and abnormal operation shutdown. The specific process of normal shutdown is that the start button is manually pressed, and the digital input card transmits the shutdown signal to the controller. The controller controls the main motor to automatically reduce the frequency to 30HZ first, then opens the return valves at all levels to complete the unloading, and then shuts down the main motor. The pre-lubrication oil pump is started to lubricate the compressor unit for five minutes and then stops lubrication. The compressor completes normal shutdown. The specific process of emergency shutdown is that the controller shuts down the compressor main motor urgently according to the signal obtained. After shutting down the compressor main motor, the compressor will no longer be lubricated. The specific process of abnormal operation shutdown is that there is an abnormality in the signal obtained by the controller. After the controller controls the compressor main motor to shut down, the pre-lubrication oil pump is started to lubricate the compressor unit for five minutes and then stops lubrication.

[0070] The beneficial effects of this embodiment are consistent with those of embodiment 2.

[0071] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A one-button starting method for a multi-stage reciprocating compressor, characterized in that: A one-button start system for a multi-stage reciprocating compressor includes a controller; an alarm unit electrically connected to the controller for sounding an alarm; a one-button start control unit including a start button; a positive pressure ventilation and fire and gas system detection unit including an air pressure transmitter, a combustible gas probe, and a flame probe electrically connected to the controller, for detecting whether the pressure in the positive pressure ventilation hood is within the required explosion-proof pressure range, and for detecting whether there is a fire or combustible gas leak in the compressor fire and gas system; an external auxiliary system detection unit including an instrument air pressure transmitter and a cooling water pressure transmitter electrically connected to the controller, for detecting whether the compressor instrument air supply pressure and the compressor cooling water pressure are normal; a signal acquisition unit electrically connected to the controller, the combustible gas probe, the flame probe, the positioners of the valves in the compressor unit, the transmitters, and the frequency converters being electrically connected to the signal acquisition unit; an air booster unit connected to the compressor instrument air supply pipeline and a cooling water booster pump connected to the compressor cooling water pipeline; and a lubricating oil heater disposed in the compressor crankcase to heat the lubricating oil, the lubricating oil heater being electrically connected to the controller. The method comprises the following steps: Step S1: Start the one-button start control unit and proceed to step S2; Step S2: positive pressure ventilation and fire and gas system detection, the air pressure transmitter transmits a signal to the controller, the combustible gas probe and the flame probe transmit a signal to the signal acquisition unit, the signal acquisition unit transmits a signal to the controller, the controller determines whether the signal meets the startup conditions, if so, proceeds to step S3, if not, the controller controls the alarm unit to sound an alarm and exits step S2; Step S3: External auxiliary system detection: the instrument air pressure transmitter and the cooling water pressure transmitter transmit signals to the controller, and the controller determines whether the signals meet the startup conditions. If so, the process proceeds to step S4. If not, the controller controls the alarm unit to sound an alarm, readjusts the compressor instrument air supply pressure and the compressor cooling water pressure to normal, and then re-enters step S3. Step S4: The internal electrical instrument system of the unit is tested. The signal acquisition unit collects signals from the valve positioners, transmitters, and inverters of each valve in the compressor and transmits the signals to the controller. The controller determines whether the status of each valve, transmitter, and inverter meets the startup conditions based on the signals. If so, the process proceeds to step S5. If not, the controller controls the alarm unit to sound an alarm and exits step S4. Step S5: System purge, the controller controls the purge valve and vent valve in the compressor unit to purge the compressor unit working chamber, compressor process pipeline and return pipeline. After the set purge time, the controller controls the pressure charging valve and vent valve in the compressor unit to pressurize the compressor unit working chamber to the set pressure and then enters step S6; Step S6: The compressor unit is pre-lubricated. The liquid level transmitter in the compressor crankcase and the hydraulic pressure transmitter at the oil outlet of the compressor pre-lubricating oil pump transmit signals to the controller. The controller determines whether the lubricating oil level in the crankcase and the lubricating oil pressure pumped out by the pre-lubricating oil pump are qualified. If so, the controller enters step S7 after a preset lubrication time. If not, the controller controls the alarm unit to sound an alarm. After adjusting to qualified conditions, the controller re-enters step S6. Step S7: Start the main motor of the compressor. The speed transmitter on the main motor of the compressor and the hydraulic pressure transmitter at the oil outlet of the main lubricating oil pump transmit signals to the controller. The controller determines whether the speed of the main motor of the compressor and the pressure of the lubricating oil pumped out by the main lubricating oil pump are within the normal range. If so, the process proceeds to step S8. If not, the controller controls the alarm unit to sound an alarm and controls the compressor unit to shut down. After adjusting to normal, the process re-enters step S6. Step S8: The controller controls the valve positioners of the compressor to control the opening and closing of the valves to adjust the loads of the compressor at each level. After the adjustment is completed, the controller determines whether the pressure signals, liquid level signals, vibration signals, and temperature signals in the compressor unit are all within the normal range. If so, the controller proceeds to step S9. If not, the controller controls the alarm unit to sound an alarm and control the compressor unit to shut down, and exits step S8. Step S9: The compressor one-button start is completed; In step S3, if the air supply pressure of the compressor instrument air system is insufficient and is still insufficient after adjusting the valves, the standby air compressor unit is activated to increase the pressure of the instrument air; if the compressor cooling water pressure is insufficient and is still insufficient after adjusting the valves, the standby cooling water booster pump is activated to increase the pressure of the cooling water; In step S4, the specific process of detecting whether the status of each valve, each transmitter, and each inverter meets the startup conditions is as follows: the controller controls the operation of each valve according to the set opening values ​​of 0, 25%, 50%, 75%, and 100%, respectively; the positioner on each valve detects the actual opening information of each valve and transmits the information to the controller; the controller then determines whether the status of each valve is consistent with the setting; if so, it means that each valve meets the startup conditions; if the controller can receive signals from each transmitter and each inverter, it means that each transmitter and each inverter are online and meet the startup conditions; In step S5, the specific process of system purge is that the controller controls the purge valve and the vent valve in the compressor unit to open at the same time, and purges the working chamber of the compressor unit, the compressor process pipeline and the return pipeline. After each purge lasts for 80 to 100 seconds, the charging valve is opened and the vent valve is closed to pressurize the working chamber of the compressor unit. After the compressor unit reaches the starting pressure of 600 to 800 kPa, the purge valve and the charging valve are closed.

2. A one-button starting method for a multi-stage reciprocating compressor according to claim 1, characterized in that: Before starting the one-button start control unit, first confirm that the upstream and downstream process flows of the compressor meet the start-up conditions, that is, the upstream production well of the compressor has been opened, the upstream and downstream processing equipment of the compressor has been put into use, and the subsea pipeline is ready for external transmission. Then confirm that the internal process flow of the compressor and the manual valves of the auxiliary system meet the start-up conditions, that is, the high-pressure safety valve, low-pressure safety valve and return valve of the internal process flow of the compressor are all in the open state, the cooling water circuit and lubricating oil circuit are in the conducting state, and the manual valves at each discharge point and waste oil discharge point are all in the closed state.

3. The one-button starting method for a multi-stage reciprocating compressor according to claim 1, characterized in that: In step S2, before detecting the pressure of the positive pressure fume hood, the instrument air inlet valve of the control cabinet is opened to ventilate the control cabinet for 4 to 6 minutes.

4. A one-button starting method for a multi-stage reciprocating compressor according to claim 1, characterized in that: In step S7 , after the pre-lubricating oil pump is started and the oil pressure is established for 8 to 12 seconds, the controller starts to determine whether the lubricating oil level signal in the crankcase and the lubricating oil pressure pumped out by the pre-lubricating oil pump are qualified.

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