Coal bed gas power generation system and control method thereof

Abstract

The invention discloses a coal bed gas power generation system and a control method thereof.The coal bed gas power generation system comprises a local end and a remote end, and the local end comprises a power generation unit used for combusting coal bed gas and converting heat energy into electric energy; the control unit is used for receiving the running state data of the power generation unit and controlling the power generation unit to start and stop; the data unit is in communication connection with the control unit through the switch and is in communication connection with a remote end; wherein the data unit receives the running state data, transmitted by the control unit, of the power generation unit, judges whether the power generation unit runs normally or not, generates a control instruction according to an instruction of a remote end or a built-in logic control program, and transmits the control instruction to the control unit to control the action of the power generation unit.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-bed methane power generation, and in particular to a coal-bed methane power generation system and a control method thereof. Background Art

[0002] Coalbed Methane (CBM) is a gas composed mainly of methane (CH 4 ) is widely found in coal seams. With the increasing demand for clean and renewable energy, the development and utilization of coalbed methane has received more and more attention and importance. Coalbed methane power generation refers to the process of using coalbed methane as fuel and converting it into electrical energy through gas turbines or internal combustion engines. This technology has significant advantages such as rich resource reserves, environmental friendliness and strong flexible scheduling capabilities, providing an important way to optimize the energy structure and improve the utilization rate of renewable energy.

[0003] At present, the startup of coal-bed methane units is basically carried out by manual intervention, which has many problems. First of all, the automation level of coal-bed methane power generation systems is generally low, and the operation process still requires a high proportion of human intervention, especially during the unit startup process, which is restricted by various factors. In particular, under the condition of fluctuating working conditions and coordinated operation of multiple units, the startup cycle is significantly extended, which suppresses production efficiency and also leads to an increase in labor costs. In addition, the existing power stations lack efficient remote monitoring and control systems, making it difficult to achieve unmanned or less-manned autonomous operation mode, which limits the flexibility and rapid response capabilities of the system, creates information islands, and makes it difficult to achieve data sharing and comprehensive analysis.

[0004] Safety hazards are also an important issue that needs to be urgently addressed in the manual startup of the current coalbed methane power generation system. Manual operation not only increases the risk of human error, but also increases the possibility of safety accidents during gas extraction and power station operation. Especially under high load or emergency conditions, the lack of timely automatic adjustment mechanisms may lead to system failures or damage to the power generation unit. At the same time, the existing units have insufficient response speed in key parameters (such as mother pipe pressure) and cannot adapt to rapidly changing operating conditions, which leads to operational instability. In addition, the production environment of coalbed methane power generation is noisy, and operators who are exposed to high noise environments for a long time may face health risks. Therefore, it is particularly important to improve the automation and intelligence level of remote one-button startup of coalbed methane power generation systems. Summary of the invention

[0005] In view of the above problems, the purpose of the present application is to provide a coalbed methane power generation system and a control method thereof.

[0006] According to one aspect of the present invention, there is provided a coalbed methane power generation system, comprising a local end and a remote end, wherein the local end comprises: a power generation unit, for burning coalbed methane and converting heat energy into electrical energy; a control unit, for receiving operating status data of the power generation unit, and controlling the start and stop of the power generation unit; a data unit, which is communicatively connected to the control unit via a switch, and is communicatively connected to the remote end; wherein the data unit receives the operating status data of the power generation unit transmitted by the control unit, and determines whether the power generation unit is operating normally, and generates control instructions according to instructions from the remote end or according to a built-in logic control program, and transmits the control instructions to the control unit to control the action of the power generation unit.

[0007] Optionally, the power generation unit includes: an internal combustion engine, which receives gas via a gas pipeline and receives air via an air pipeline, the internal combustion engine receives gas and air in a predetermined ratio and burns to convert heat energy generated by the combustion into mechanical energy; a generator, which converts the mechanical energy generated by the internal combustion engine into electrical energy; and a unit controller, which is respectively connected to the internal combustion engine and the generator, and the unit controller is communicatively connected to the control unit to receive control instructions from the control unit.

[0008] Optionally, the control unit includes a field controller and an extended communication module, and the field controller is communicatively connected with the unit controller via the communication module.

[0009] Optionally, the local end also includes a sensor unit, the control unit also includes an extended analog input module, and the field controller is communicated with the sensor unit via the analog input module; the sensor unit is used to collect field operation data, the analog input module converts the analog signal of the sensor unit into an electrical signal, and transmits the electrical signal to the field controller for logical calculation.

[0010] Optionally, the local end also includes a valve control unit, and the control unit also includes an extended analog output module. The field controller is communicated with the valve control unit via the analog input module. The valve control unit controls the opening of the gas valve to adjust the flow rate of the gas input, and at the same time controls the opening of the air valve to adjust the oxygen supply.

[0011] Optionally, the local end further includes a digital input and output module, and the control unit is connected to the field device of the power generation unit via the digital input and output module.

[0012] Optionally, the remote end includes an intelligent terminal and a server, and the intelligent terminal interacts with the data unit through the server.

[0013] According to another aspect of the present invention, there is provided a control method for a coalbed methane power generation system, including a starting method and a stopping method, the starting method including: judging whether the starting conditions are met; starting when the starting conditions are met; setting the target power after successful starting, and the power generation unit operates at the target power; the stopping method including setting the unloading power, reducing the speed and power of the power generation unit to the unloading power by adjusting the air and gas opening and reducing the gas, and when the water temperature and oil temperature reach the unloading conditions, the power generation unit is stopped; wherein, manual mode and automatic mode are included, the manual mode can operate the power generation unit through the human-computer interaction unit according to on-site needs, and in the automatic mode, the data unit automatically operates the power generation unit according to a preset program.

[0014] Optionally, after starting up, when the state parameters of the power generation unit reach the constant speed condition, the power generation unit is converted into the constant speed operation mode.

[0015] Optionally, after entering the constant speed operation mode, the gas and air openings are fine-tuned, and the grid is connected when the speed reaches a predetermined speed.

[0016] The embodiment of the present application improves the automation and intelligence level of the remote one-key start of the coalbed methane power generation system by setting a local end and a remote end. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings, in which:

[0018] Figure 1 A schematic block diagram of a coalbed methane power generation system provided according to an embodiment of the present application is shown;

[0019] Figure 2 A schematic block diagram of a power generation unit 110 provided according to an embodiment of the present application is shown;

[0020] Figure 3 A schematic block diagram of a control unit 120 provided according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] The present application will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown.

[0022] This application may be presented in a variety of forms, some examples of which are described below.

[0023] Figure 1 A schematic block diagram of a coal bed methane power generation system provided according to an embodiment of the present application is shown. Figure 1As shown, the coalbed methane power generation system includes a local end 100 and a remote end 200. The local end 100 includes a power generation unit 110, a control unit 120, a human-computer interaction unit 130, a switch 140 and a data unit 150. The remote end 200 includes an intelligent terminal 210 and a server 220.

[0024] Figure 2 A schematic block diagram of a power generation unit 110 provided according to an embodiment of the present application is shown. Figure 2 As shown, the power generation unit 110 includes an internal combustion engine 111, a generator 112 connected to the internal combustion engine 111, and a group controller 113 connected to the internal combustion engine 111 and the generator 112 respectively.

[0025] The internal combustion engine 111 is connected to the extraction station 300 via the gas pipeline 115, and the extraction station 300 provides gas to the internal combustion engine 111 via the gas pipeline 115. During the operation of the extraction station 300, the extraction power generation unit in the extraction station 300 outputs the gas from the underground, but due to the natural volatility of the gas source, the concentration and pressure in the gas pipeline 115 often show great instability. Therefore, a relief valve 116 and a gas valve 117 are set on the gas pipeline 115. The relief valve 116 is used to discharge the gas in the gas pipeline 115 when the pressure in the gas pipeline 115 is too high, and the gas valve 117 is used to adjust the flow of the gas in the gas pipeline 115. The gas is initially roughly regulated by using the gas pipeline 115 and the release valve 116 and gas valve 117 and other related equipment equipped on site of the power generation unit 110. This regulation process mainly stabilizes the concentration and pressure of the gas source to a certain extent by regulating the flow of the gas pipeline 115 and releasing the excess gas, thus providing relatively balanced basic conditions for the operation of the subsequent internal combustion engine 111 and the generator 112 and other equipment. The air pipeline 114 is used to provide air for the internal combustion engine 111. The air pipeline 114 is provided with an air valve 118 for regulating the flow of air in the air pipeline 114. The gas pipeline 115 provides gas to the internal combustion engine 111, and the air pipeline 114 provides air to the internal combustion engine 111. By controlling the opening of the gas valve 117 on the gas pipeline 115 and the opening of the air valve 118 on the air pipeline 114, a mixed gas of a predetermined proportion is provided to the internal combustion engine 111. The internal combustion engine 111 burns the mixed gas of the predetermined proportion and converts the heat energy generated by the combustion of the gas and air into mechanical energy, and the generator 112 converts the mechanical energy into electrical energy.

[0026] The unit controller 113 is the main control module of the internal combustion engine 111. The unit controller 113 is connected to the control unit 120 for communication and receives control instructions from the control unit 120. The unit controller 113 is mainly responsible for executing operations such as the control of the gas valve 117 and the air valve 118, the fuel supply ratio adjustment of the combustion chamber, and the start and shut down of the cooling system.

[0027] Figure 3 A schematic block diagram of a control unit 120 provided according to an embodiment of the present application is shown. Figure 3 As shown, the control unit 120 includes a field controller 121 and an extended communication module 122, and the field controller 121 is connected to the unit controller 113 via the communication module 122. In one embodiment, the field controller 121 adopts an S7-1215 PLC module, and the extended communication module 122 adopts a 485 communication module (such as CM1241). The communication module 122 supports the Modbus RTU protocol to realize serial communication between the field controller 121 and the unit controller 113. The communication module 122 converts the control signal of the field controller 121 into protocol data that can be received by the unit controller 113, and receives the status data fed back by the unit controller 113.

[0028] Further, the control unit 120 also includes an extended analog input module 123, and the analog input module 123 adopts an SM1231 module, for example. The field controller 121 is connected to the sensor unit 160 via the analog input module 123. The sensor unit 160 is used to collect key data of field operation. The sensor unit 160 may include a temperature sensor, a gas concentration sensor, and a pressure sensor. The temperature sensor is used to collect data such as exhaust temperature and cooling water temperature of the internal combustion engine 111 unit to directly reflect the working temperature of the internal combustion engine 111; the gas concentration sensor is used to collect the gas concentration in the gas pipeline 115, and the pressure sensor is used to collect the gas pressure in the gas pipeline 115 and the air pressure in the air pipeline 114 to ensure the stability of the gas supply and the oxygen supply required for combustion. The analog input module 123 converts the analog signal into a standard electrical signal, and transmits the standard electrical signal to the field controller 121 for logical calculation.

[0029] Further, the control unit 120 also includes an extended analog output module 124, and the analog output module 124 adopts an SM1231 module, for example. The field controller 121 is connected to the valve control unit 170 via the analog input module 123. The valve control unit 170 controls the opening of the gas valve 117 to adjust the flow of the gas input to ensure the fuel supply of the internal combustion engine 111; at the same time, by accurately controlling the opening of the air valve 118, the oxygen supply is adjusted to match the fuel (gas) ratio to ensure sufficient combustion. The control of the combustible ratio can be used to control the power output of the power generation unit 110, and at the same time, the core equipment of the power generation unit 110 is prevented from being damaged by excessive gas (gas) or air. The analog output module 124 is used to convert the control signal generated by the field controller 121 into an analog output, which is used to accurately adjust the field execution device, such as adjusting the opening of the gas valve or the air valve, controlling the combustion ratio of gas and air, ensuring that the temperature, pressure and other values ​​are controlled in real time, avoiding operation beyond the safety range, and ensuring that the unit operates at the highest efficiency.

[0030] Furthermore, it also includes a digital quantity input and output module 180, and the control unit 120 is connected to the field equipment of the power generation unit 110 via the digital quantity input and output module 180, and the field equipment includes but is not limited to the internal combustion engine, the generator, the cooling water pump and the alarm device. The digital quantity input and output module 180 collects important switch quantity signals of the power generation unit 110, such as the start / stop state of the internal combustion engine, the high / low negative pressure alarm signal of the gas pipeline 115 and the air pipeline 114, and the equipment failure signal feedback. The switch quantity signal is transmitted to the field controller 121 by the digital quantity input and output module 180; at the same time, the field controller 121 sends an output signal to the power generation unit 110 via the digital quantity input and output module 180, such as: starting or stopping the generator, starting the cooling water pump or the alarm device, and these signals act directly on the equipment to realize specific operations.

[0031] Furthermore, the data unit 150 acts as the central processor of the system, responsible for summarizing the signals of the field devices and performing core logic operations, and communicates with the control unit 120 through the network switch 140. The control unit 120 (specifically the field controller 121) is a field control unit responsible for processing all sensor data received from the digital input and output module 180 (DI module) and the analog input module 123 (AI module). The data unit 150 receives field acquisition data and execution feedback from the control unit 120. After receiving the acquisition data, the data unit 150 will determine whether the operation of the power generation unit is stable according to the logic program. If an abnormality is found, such as the gas concentration is too low or the cooling water temperature exceeds the standard, it will be transmitted to the smart terminal 210 through the server 220 to alarm or adjust the external control signal. Under the premise of safe operation of the system, the data unit 150 generates control instructions according to the smart terminal 210 or according to the internal logic control program, and transmits them to the control unit 120 to control the operation of the power generation unit 110, such as controlling the switch of the core operating equipment of the gas unit (such as the unit start-up signal, cooling pump, etc.), executing actual actions (such as on / off signals or alarm signals), or according to the instructions of the data unit 150, transmitting the output data to the power generation unit 110 via the analog output module 124 and the digital input and output module 180 to adjust the gas valve, control the generator, etc.

[0032] The intelligent terminal 210 interacts with the server 220 (distributed control system) through remote communication. The intelligent terminal monitors and remotely operates the power generation unit 110 in real time, including viewing key parameters (gas concentration, gas pressure, temperature), setting operating thresholds, and issuing operating control instructions (such as starting / stopping the unit or modifying the valve opening). When a system failure occurs, the terminal will receive an alarm message, realize real-time fault prompts, and provide timely decision-making support for operation and maintenance personnel.

[0033] The server 220 is, for example, a DCS server. The server 220 is the data concentrator and distribution center of the entire system. It communicates with the data unit 150, aggregates the system's operating data (such as unit status, sensor signals) and presents them to the smart terminal 210. The server 220 not only processes the operating data uploaded from the data unit 150, but also transmits the control instructions (such as parameter adjustment) issued by the smart terminal 210 to the data unit 150. It can also store operating history data for subsequent analysis, optimization or maintenance.

[0034] The control method of the coalbed methane power generation system includes a startup method and a shutdown method.

[0035] S110: Determine whether the startup condition is met;

[0036] S120: Start the machine when the start conditions are met;

[0037] S130: After the startup is successful, the target power is set, and the power generation unit operates at the target power.

[0038] In step S110, the data unit 150 obtains the fault information of all signal points of the power generation unit 110. When the fault information of all signal points shows no fault, the start-up condition is met. Before the power generation unit 110 is started, the data unit 150 obtains the state parameters of the power generation unit 110, such as the water temperature, oil temperature, oil pressure and other parameters of the internal combustion engine in the power generation unit 110. If the state parameters meet the preset conditions, no alarm will be given. If they do not meet the preset conditions, an alarm will be given and a fault will be displayed. If all signal points of the power generation unit 110 have no fault output signals, it can be started. If there is fault information, the data unit 150 will determine the fault point through the program, and further troubleshoot the fault until the fault is resolved.

[0039] Furthermore, after the start-up conditions are met, the step of preparing for the start-up is also included, wherein the step of preparing for the start-up includes turning on the mode switch and checking whether the human-machine interaction unit 130 can normally adjust the basic air idle opening and the basic gas idle opening. The human-machine interaction unit 130 is, for example, a touch display screen, which displays a mode switch, and when the mode switch is turned on, the manual mode and the automatic mode can be selected through the mode switch. In the manual mode, the power generation unit 110 can be operated through the human-machine interaction unit 130 according to the on-site requirements, such as starting and stopping the power generation unit 110, adjusting the air and gas openings, etc. In the automatic mode, the data unit 150 automatically operates the power generation unit 110 according to the preset program.

[0040] Next, the air idle basic opening and the gas idle basic opening are adjusted in manual mode. If the gas opening and the air opening cannot be adjusted normally, personnel are arranged to handle the fault until the human-machine interaction unit 130 can smoothly adjust the air and gas openings.

[0041] Next, enter step S120 to start the power generation unit 110. The power generation unit 110 can be started in manual mode or automatic mode. During the startup of the power generation unit 110, the air opening, gas opening, etc. are adjusted. After the state parameters such as the water temperature, oil temperature, and speed of the power generation unit 110 reach the constant speed condition, the power generation unit 110 is converted to the constant speed operation mode.

[0042] After the power generation unit 110 enters the fixed speed operation mode, the gas and air openings are fine-tuned according to other factors such as the on-site gas source concentration and pressure. When the speed reaches a predetermined speed (e.g., 980rpm-1020rpm), the power generation unit 110 is connected to the grid. If the speed does not reach the predetermined speed, the motor speed is obtained after the gas and air openings are fine-tuned.

[0043] The motor is connected to the grid and maintained for a predetermined time (e.g., 80 seconds). If the motor still runs at a constant speed within the predetermined time, the startup is successful. If the motor cannot run normally within the predetermined time, try to close the switch and connect to the grid again. If the motor still cannot run normally after the number of grid connections exceeds the predetermined number, an alarm is issued to handle the fault. After the fault is handled, steps S110 and S120 are repeated.

[0044] In step S130, the target power is set after the switch is closed, and the motor runs at the target power.

[0045] Furthermore, the shutdown method includes setting the unloading power, adjusting the air and gas opening to reduce the unit speed and power to the unloading power (for example, within 40KW), and when the water temperature and oil temperature reach the unloading conditions, the unit is shut down. You can also choose to shut down in automatic mode or manual mode.

[0046] The embodiments of the present application are described above, and these embodiments do not describe all the details in detail, nor do they limit the application to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and the modifications based on the present application. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. A coalbed methane power generation system, comprising a local end and a remote end, wherein the local end comprises: A power generation unit for burning coal-bed methane and converting heat energy into electricity; A control unit receives the operating status data of the power generation unit and controls the start and stop of the power generation unit; A data unit is communicatively connected to the control unit via the switch and is communicatively connected to the remote end; The data unit receives the operating status data of the power generation unit transmitted by the control unit, determines whether the power generation unit is operating normally, and generates control instructions according to the instructions of the remote end or according to the built-in logic control program, and transmits them to the control unit to control the action of the power generation unit.

2. The coalbed methane power generation system according to claim 1, wherein: The power generation unit includes: An internal combustion engine, the internal combustion engine receiving gas via a gas pipeline and air via an air pipeline, the internal combustion engine receiving gas and air in a predetermined ratio and performing combustion to convert heat energy generated by the combustion into mechanical energy; Generators, which convert the mechanical energy produced by the internal combustion engine into electrical energy; and The unit controller is connected to the internal combustion engine and the generator respectively, and the unit controller is in communication connection with the control unit to receive control instructions from the control unit.

3. The coalbed methane power generation system according to claim 2, wherein: The control unit includes a field controller and an extended communication module, and the field controller is communicatively connected with the unit controller via the communication module.

4. The coalbed methane power generation system according to claim 3, wherein: The local end also includes a sensor unit, and the control unit also includes an extended analog input module. The field controller is communicated with the sensor unit via the analog input module; the sensor unit is used to collect field operation data, and the analog input module converts the analog signal of the sensor unit into an electrical signal, and transmits the electrical signal to the field controller for logical calculation.

5. The coalbed methane power generation system according to claim 3, wherein: The local end also includes a valve control unit, and the control unit also includes an extended analog output module. The field controller is communicated with the valve control unit via the analog input module. The valve control unit controls the opening of the gas valve to adjust the flow rate of the gas input, and at the same time controls the opening of the air valve to adjust the oxygen supply.

6. The coalbed methane power generation system according to claim 3, wherein: The local end also includes a digital input and output module, and the control unit is connected to the field equipment of the power generation unit via the digital input and output module.

7. The coalbed methane power generation system according to claim 1, wherein: The remote end includes an intelligent terminal and a server, and the intelligent terminal interacts with the data unit through the server.

8. A control method for a coalbed methane power generation system, comprising a startup method and a shutdown method, wherein the startup method comprises: Determine whether the startup conditions are met; Start the machine when the start conditions are met; After the startup is successful, the target power is set and the power generation unit operates at the target power; The shutdown method includes setting the unloading power, adjusting the air and gas opening to reduce the speed and power of the power generation unit to the unloading power, and when the water temperature and oil temperature reach the unloading condition, the power generation unit is shut down; Among them, there are manual mode and automatic mode. In manual mode, the power generation unit can be operated through the human-computer interaction unit according to on-site needs. In automatic mode, the data unit automatically operates the power generation unit according to the preset program.

9. The control method according to claim 8, wherein: After starting, when the state parameters of the power generation unit reach the constant speed condition, the power generation unit switches to the constant speed operation mode.

10. The control method according to claim 8, wherein: After entering the constant speed operation mode, fine-tune the gas and air openings, and connect to the grid when the speed reaches the preset speed.

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