CN111350595A - A micro gas turbine generator wellhead shale gas supply device control system - Google Patents

Abstract

The invention discloses a control system for a micro gas turbine generator wellhead shale gas supply device. The control protection system includes a particle droplet control system, a temperature control system, a pressure control system, a liquid level control system, a water hydrocarbon dew point control system, a precision The processing control system and the system safety protection system are set up independently of each other. The working condition parameter signal acquisition system transmits the collected signals to the logic judgment command system, which is respectively connected with the parameter setting system, the control protection system and the data storage remote transmission system. , the micro gas turbine power generation system is respectively connected with the parameter setting system, the control protection system and the data storage remote transmission system. Beneficial effects: realize the stable control of the dew point of water and hydrocarbons, ensure the normal and stable operation of the micro gas turbine; carry out precise control of sewage discharge according to the fluctuation of actual working conditions, and reduce the overall operating cost; realize automatic discharge under different working conditions. Reduces the risk of tripping and escaping.

Description

A micro gas turbine generator wellhead shale gas supply device control system

technical field

The invention relates to the field of shale gas, in particular to a control system of a micro gas turbine generator wellhead shale gas supply device.

Background technique

In the process of shale gas fracturing, multiple sets of high-power electrical equipment are required to work continuously, and most of the gas wells are located in remote areas. It is difficult for the surrounding power grid facilities to ensure the power supply of the electrical equipment required for the fracturing process. Conventional diesel generator sets need to be equipped with a large amount of diesel , the cost and freight are very high. If the shale gas gas turbine generator set is used, the fuel can be obtained on the spot, the floor space is small, and the cost advantage is large.

At present, the existing gas supply control systems for micro gas turbines are generally used in pipeline gas and liquefied natural gas, but cannot be used in wellhead shale gas. This is because the shale gas well fluctuates more in the working conditions, and shale gas water and hydrocarbons under different working conditions The dew point is different, and the shale gas, water and hydrocarbon dew point can work normally only when it is in a safe range. However, the target operating condition of the existing system has a small variation range and is not controlled according to the actual operating condition fluctuation value. A fixed dew point is directly determined according to the cooling temperature of the system, so it cannot adapt to the fluctuation range of shale gas conditions and the requirements of normal and stable operation of gas turbines; at the same time, the liquid level control of the existing system is difficult to adapt to the operation of gas coming from shale gas wells. For example, the vast majority of systems use a water delivery valve, which automatically removes liquid when there is liquid, and automatically closes after draining. However, when the pressure and flow of shale gas fluctuate widely, and there may be other pressure changes in a large range, the trap cannot be closed in time or reliably.

SUMMARY OF THE INVENTION

The object of the present invention overcomes the deficiencies of the prior art, and provides a micro gas turbine generator wellhead shale gas supply device control system, which realizes the stable control of the dew point of water and hydrocarbons and automatic liquid drainage under the condition of fluctuating working conditions, and reduces the tripping and the series. It can ensure the normal and stable operation of the micro gas turbine, reduce the overall operating cost, and provide a stable power supply for various electrical equipment in the shale gas fracturing operation.

The purpose of the present invention is achieved through the following technical measures: a micro gas turbine generator wellhead shale gas supply device control system, including a working condition parameter signal acquisition system (1), a parameter setting system (2), a logic judgment command system (3), a data storage remote transmission system (4), a control protection system (5) and a micro gas turbine power generation system (13), the control protection system (5) includes a particle droplet control system (6), a temperature control system ( 7), a pressure control system (8), a liquid level control system (9), a water hydrocarbon dew point control system (10), a finishing control system (11), and a system safety protection system (12) and are arranged in parallel independently of each other, said The water-hydrocarbon dew point control system (10) is used to determine the dew point values of different working conditions, so as to realize the stable control of the water-hydrocarbon dew point under the fluctuation of the working conditions, and the liquid level control system (9) is used to realize the automatic sewage discharge under the fluctuation of the working conditions. The finishing control system (11) is used to realize the precise blowdown of the liquid level control system (9) and prevent the continuous precipitation of water and hydrocarbons from the shale gas, and the working condition parameter signal acquisition system (1) transmits the acquisition signal to the logic A judgment command system (3), the logic judgment command system (3) is respectively connected with a parameter setting system (2), a control protection system (5) and a data storage remote transmission system (4), the micro gas turbine power generation system (13) ) are respectively connected with the parameter setting system (2), the control protection system (5) and the data storage remote transmission system (4).

Further, the water-hydrocarbon dew point control system (10) includes a refrigeration unit, a cooler, a coolant bypass valve of the cooler, a pipeline and pipeline accessories, and the refrigeration unit is used to realize the water vapor and heavy metals in the shale gas. Condensation of hydrocarbons, the cooler is used to achieve heat exchange between the carrier refrigerant and the shale gas, and the cooler carrier refrigerant bypass valve is used to adjust the flow rate of the cooler carrier refrigerant.

Further, the finishing control system (11) includes a differential pressure transmitter, a temperature compensation sensor, a flowmeter, a cable and cable accessories, the flowmeter is used to obtain the actual flow value of shale gas, and the differential pressure changes. The transmitter and temperature compensation sensor are used to calibrate the flowmeter.

Further, the liquid level control system (9) includes a liquid level detection element, an automatic blowdown valve, a manual blowdown valve, a one-way valve, a separator and a blowdown pipe, and the manual blowdown valve and the automatic blowdown valve are arranged in parallel for blowdown. , the liquid level detection element is used to realize the real-time monitoring of the liquid level value.

Compared with the prior art, the present invention has the beneficial effects of: controlling the water and hydrocarbon dew point values under different working conditions through the water hydrocarbon dew point determination system, realizing the condensation and precipitation of water vapor and heavy hydrocarbons under the condition of fluctuating working conditions, and achieving the stability of the water and hydrocarbon dew point. control to meet the dew point requirements of shale gas water and hydrocarbon dew point for micro gas turbines and ensure the normal and stable operation of micro gas turbines. Precipitation, while reducing the overall operating cost; the liquid level control system realizes automatic liquid drainage under different working conditions fluctuations, and reduces the risk of tripping and gas leakage.

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a schematic diagram of a control system of a micro gas turbine generator wellhead shale gas supply device.

The numbers in the drawings are: 1. Working condition parameter signal acquisition system, 2. Parameter setting system, 3. Logic judgment command system, 4. Data storage and remote transmission system, 5. Control protection system, 6. Particle droplet control system , 7. Temperature control system, 8. Pressure control system, 9. Liquid level control system, 10. Water hydrocarbon dew point control system, 11. Finishing control system, 12. System safety protection system, 13. Micro gas turbine power generation system.

Detailed ways

As shown in Figure 1, a micro gas turbine generator wellhead shale gas supply device control system includes a working condition parameter signal acquisition system 1, a parameter setting system 2, a logic judgment command system 3, a data storage remote transmission system 4, a control system A protection system 5 and a micro gas turbine power generation system 13, the control protection system 5 includes a particle droplet control system 6, a temperature control system 7, a pressure control system 8, a liquid level control system 9, a water hydrocarbon dew point control system 10, and finishing control The system 11 and the system safety protection system 12 are independently and juxtaposed to each other. The water-hydrocarbon dew point control system 10 is used to determine the dew point value of different working conditions, so as to realize the stable control of the water-hydrocarbon dew point under the fluctuation of working conditions. The liquid level control system 9 In order to realize automatic blowdown under fluctuating working conditions, the finishing control system 11 is used to realize the precise blowdown of the liquid level control system 9 and prevent the continuous precipitation of water and hydrocarbons in the shale gas output. The operating condition parameter signal acquisition system 1 The collected signal is transmitted to the logical judgment command system 3, which is respectively connected with the parameter setting system 2, the control protection system 5 and the data storage remote transmission system 4, and the micro gas turbine power generation system 13 is respectively connected with the parameter setting system. 2. The control protection system 5 is connected with the data storage remote transmission system 4 .

The working condition parameter signal acquisition system 1 includes a temperature detection element, a pressure detection element, a flow detection element, a differential pressure detection element, a liquid level detection element, a signal cable and a pressure root valve, and the working condition parameter signal acquisition system 1 passes through the temperature detection element. The temperature is detected and transmitted to the logic judgment command system through the signal cable. Similarly, the flow detection element, the pressure difference detection element, and the liquid level detection element transmit the detected flow, pressure difference, and liquid level signals to the logic judgment command system 3.

The parameter setting system 2 includes a signal input component, a transmission cable and a storage component, and the parameter setting system 2 provides an input interface and a human-computer interaction interface, performs manual or automatic input of the control program and the set value, and transmits it to the logic judgment through the cable. Command system 3, and parameter setting system 2 have built-in parameter setting ranges to meet the automatic acquisition of parameters under different working conditions.

The digital signals of key parameters such as the intake pressure, temperature, rotational speed, vibration value, etc. of the micro gas turbine power generation system 13 are input through the interface in the parameter setting system.

The logic judgment command system 3 includes a logic control unit, an I/O input/output unit, a power supply and an instruction storage unit, so as to satisfy the judgment of different parameters.

The data storage and remote transmission system 4 includes a storage unit, a transmission unit, a data conversion unit and a display unit, which can satisfy the real-time display of parameters and the adjustment of parameters at a certain time during the operation of a single or multiple micro gas turbine generator wellhead shale gas supply devices. It can be collected and analyzed in order to realize remote scheduling decision, remote emergency shutdown, etc.

The particle droplet control system 6 includes a particle droplet filtering unit, an inspection and cleaning unit and a pipeline unit. The particle droplet filtering unit is used to remove most of the particles and droplets larger than 10 μm in the shale gas. Regular inspection and cleaning of the inspection and cleaning unit ensures that the removal efficiency is stable above 99-99.9%, which meets the control of the content and size of particles and droplets by the gas turbine.

The temperature control system 7 includes a heating unit and a cooling unit. The cooling unit adopts a refrigerator, and the heating unit adopts an electric heater. The temperature control system 7 is used to meet the temperature requirements of the gas turbine intake air. Optionally, the cooling unit can be a cold dryer, and the heating unit can be heated by a hot water/steam/water jacket furnace.

The pressure control system 8 includes a pressure regulating valve, a pressure taking pipe and a root valve to meet the requirements of the gas turbine for the intake pressure.

The water-hydrocarbon dew point control system 10 includes a refrigeration unit, a cooler, a heat preservation component, a circulating water pump, a gas-liquid separator, a coolant inlet and outlet valve of the cooler, a natural gas inlet valve of the cooler and a bypass valve of the coolant carrier of the cooler, Pipes and pipe accessories, the refrigeration unit is used to realize the condensation of water vapor and heavy hydrocarbons in the shale gas, the cooler is used to realize the heat exchange between the refrigerant and the shale gas, and the cooler is used to carry the cooling The agent bypass valve is used to adjust the flow rate of the coolant in the cooler, and to adapt to the changing conditions of the flow rate of shale gas in a wider range. Through previous prediction methods, such as test wells, the temperature variation range, flow rate variation range, pressure variation range, composition variation range and water content variation range of shale gas are obtained, and then the maximum and minimum values of dew point are determined. The interpolation method determines n intermediate values (n≥0), and finally obtains the theoretical dew point values under different working conditions: the highest value, the lowest value, the intermediate value 1...the intermediate value n (n≥0), the logical judgment system 3 will dew point The theoretical value and its corresponding shale gas inlet temperature, flow rate and pressure are stored in the shale gas parameter group of the parameter setting system 2, and at the same time, the flow rate of the carrier refrigerant corresponding to the theoretical value of different dew points and the carrier refrigerant at the inlet of the cooler are determined. The temperature of the shale gas is stored in the shale gas parameter group of the parameter setting system 2; the shale gas composition is built in the parameter setting system 2, and the operator can also obtain the real-time shale gas composition through the gas chromatograph, and convert the real-time shale gas composition to the gas chromatograph. The shale gas composition is stored in the shale gas parameter group of the parameter setting system 2; the logical judgment command system 3 collects the shale gas intake transmitted by the system 1 according to the shale gas composition transmitted by the parameter setting system 2 and the working condition parameter signal. temperature, pressure and flow rate, select the closest set of values in the shale gas parameter group of the parameter setting system 2, and take the refrigerant flow rate and the refrigerant temperature at the inlet of the cooler as the current target value, The refrigeration unit is controlled according to the required temperature of the refrigerant at the inlet of the cooler; the working condition parameter signal acquisition system 1 is provided with a temperature detection element at the inlet of the cooler, which detects the actual temperature of the refrigerant at the inlet of the cooler in real time and converts it into The electrical signal is sent to the logical judgment command system 3, and the parameter setting system 2 also has an allowable temperature deviation range. If the deviation between the temperature detected by the working condition parameter signal acquisition system 1 and the target value exceeds the allowable temperature deviation range, the logical judgment Command system 3 issues adjustment instructions, and the operator adjusts the opening of the coolant bypass valve of the cooler until it meets the requirements, so as to realize the continuous stability of the outlet temperature of the refrigeration unit under different working conditions, so that water vapor and heavy hydrocarbons can be condensed under fluctuating working conditions. Precipitation, so as to achieve stable control of the water and hydrocarbon dew point, meet the requirements of the micro gas turbine for the water and hydrocarbon dew point of the shale gas, and ensure the normal and stable operation of the micro gas turbine. Optionally, the refrigeration unit can be replaced by a refrigerating machine; the flow of the refrigerant can be automatically controlled, and the inlet and outlet valves of the refrigerant in the cooler can be replaced with electric or pneumatic control valves.

The liquid level control system 9 includes a liquid level detection element, an automatic blowdown valve, a manual blowdown valve, a one-way valve, a separator and a blowdown pipe. The manual blowdown valve and the automatic blowdown valve are arranged in parallel for blowdown. The detection element is used to realize the real-time monitoring of the liquid level value; according to the shale gas inlet temperature variation range, flow variation range and pressure variation range obtained by the previous prediction method, the lowest liquid level value under different working conditions is determined, and different working conditions are determined. The lowest liquid level value of the liquid level is stored in the parameter setting system 2, and the high and high stop value, high alarm value, high adjustment value, low adjustment value, low alarm value and low and low stop value of the liquid level are set at the same time and stored in the parameter setting system. In 2; the working condition parameter signal acquisition system 1 detects the shale gas inlet temperature, flow rate and pressure in real time and converts it into an electrical signal and transmits it to the logic judgment command system 3. The logic judgment command system 3 retrieves the received temperature, flow rate and pressure The closest minimum liquid level value in the parameter setting system 2 is taken as the minimum liquid level value allowed under the current working condition, and the liquid level is detected in real time by the liquid level detection element of the liquid level control system 9. When the liquid level reaches a high level, the adjustment When the liquid level reaches the low regulation value, the logic judgment command system 3 sends an instruction to close the automatic sewage valve; When the blowdown valve is faulty, it can be drained through the manual blowdown valve. Optionally, the low and low shutdown values can be set to be automatically adjusted, the liquid level detection element can choose a magnetic flap or other types of liquid level gauges, and the automatic drain valve can choose a pneumatic switch valve or an axial flow pneumatic switch valve or an electric axial flow switch valve or pneumatic electric control valve.

The finishing control system 11 includes a differential pressure transmitter, a temperature compensation sensor, a flowmeter, a pressure compensation sensor, cables and cable accessories, the flowmeter is used to obtain the actual flow value of shale gas, and the pressure difference changes. The transmitter and temperature compensation sensor are used to calibrate the flowmeter. According to the logical judgment command system 3 selects the closest set of values in the shale gas parameter group of parameter setting system 2, takes the theoretical dew point value as the current dew point value, and obtains the current dew point value according to the obtained current dew point value and the previous prediction. The fluctuating range of shale gas flow according to the shale gas flow rate is obtained, and the amount of sewage required by the liquid level control system 9 is obtained. Combined with the diameter of the separator, the diameter of the sewage pipe and the actual flow value of the shale gas obtained, the theoretical time that the automatic sewage valve needs to be opened is determined. range and store it in the parameter setting system 2, the flowmeter measures the actual flow of shale gas within the theoretical time range and stores it in the parameter setting system 2, and the logic judgment system 3 calculates the shale gas before the automatic blowdown valve is opened. The accumulated flow rate is converted into the liquid volume that the separator needs to discharge, and then combined with the real-time liquid level, the actual time that the automatic sewage valve needs to be opened is obtained, and the obtained actual time is compared with the fixed liquid storage time of the liquid level control system 9. The smaller value between the two is taken as the optimal opening time of the automatic blowdown valve to achieve accurate blowdown, further improve the ability to prevent blowdown of air from blowing off the blowdown, and then achieve accurate and reliable control of the dew point. According to the obtained current dew point value, the temperature control target value z is obtained through the temperature control target value z=(current dew point value+y)°C (y≥0, y is the margin required by the gas turbine, corresponding to the requirements of the gas turbine), The parameter setting system 2 has an allowable temperature deviation range, and the logical judgment command system 3 compares the shale gas output gas temperature collected by the working condition parameter signal acquisition system 1 with the temperature control target value z to prevent the shale gas output gas water and hydrocarbons from continuing. Precipitation: when the collected temperature is lower than the temperature control target value z, the logic judgment command system 3 sends an instruction to turn on the heating unit of the temperature control system 7 to increase the temperature until it is close to the temperature control target value z with the allowable temperature deviation range; When the temperature of the heater is higher than the temperature control target value z, the logic judgment command system 3 sends an instruction to turn off the heating unit, which saves the power consumption of the system and reduces the overall operating cost.

The system safety protection system 12 includes a shut-off valve, a safety release valve, a pressure release valve, a manual release valve, a warning light, a buzzer and a pipeline cable. The system safety protection system 12 includes a pressure sub-protection system. The system has triple protection: pressure relief valve and manual relief valve are respectively set in particle droplet control system 6, finishing control system 11 and pressure control system 8 to meet the timely relief of pressure everywhere in emergency situations and realize the first level of pressure protection ;The working condition parameter signal acquisition system 1 transmits the pressure of the measuring point to the logic judgment command system 3 through the cable. When the alarm value is reached, it will alarm through the indicator light and buzzer, and the logic judgment command system 3 outputs the signal. The alarm content is displayed in the human-computer interaction interface of 2 for the operator to judge and operate to realize the second pressure protection; when the detection pressure of the working condition parameter signal acquisition system 1 reaches the set cut-off pressure, the logic judgment command system 3. Issue an instruction to cut off the shut-off valve in time to realize the third pressure protection.

The technical solution described in the present invention determines the water and hydrocarbon dew point value under different working conditions through the water and hydrocarbon dew point control system, realizes the condensation and precipitation of water vapor and heavy hydrocarbons under the condition of fluctuation of working conditions, achieves stable control of the water and hydrocarbon dew point, and satisfies the requirements of micro gas turbines. The dew point requirements of rock gas water and hydrocarbons ensure the normal and stable operation of the micro gas turbine; the polishing control system precisely controls the blowdown according to the fluctuations of the actual working conditions, and prevents the continuous precipitation of water and hydrocarbons in the shale gas output, and reduces the overall operation. Cost; the liquid level control system realizes automatic liquid drainage under different working conditions fluctuations, and reduces the risk of tripping and air leakage.

Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments, and the descriptions in the above-mentioned embodiments and the description are only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have Various changes and modifications fall within the scope of the claimed invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (4)

1. The utility model provides a miniature gas turbine generator well head shale gas air feeder control system which characterized in that: the device comprises a working condition parameter signal acquisition system (1), a parameter setting system (2), a logic judgment command system (3), a data storage and remote transmission system (4), a control protection system (5) and a micro gas turbine power generation system (13), wherein the control protection system (5) comprises a particle liquid drop control system (6), a temperature control system (7), a pressure control system (8), a liquid level control system (9), a water hydrocarbon dew point control system (10), a fine processing control system (11) and a system safety protection system (12), which are independent and arranged in parallel, the water hydrocarbon dew point control system (10) is used for determining dew point values of different working conditions, so that stable control of water hydrocarbon dew points under working condition fluctuation is realized, the liquid level control system (9) is used for realizing automatic pollution discharge under working condition fluctuation, the fine processing control system (11) is used for realizing accurate pollution discharge of the liquid level control system (9) and preventing continuous precipitation of water hydrocarbon of shale gas outlet, the working condition parameter signal acquisition system (1) transmits an acquired signal to the logic judgment command system (3), the logic judgment command system (3) is respectively connected with the parameter setting system (2), the control protection system (5) and the data storage remote transmission system (4), and the micro gas turbine power generation system (13) is respectively connected with the parameter setting system (2), the control protection system (5) and the data storage remote transmission system (4).

2. The micro gas turbine generator wellhead shale gas supply device control system of claim 1, wherein: the water hydrocarbon dew point control system (10) comprises a refrigerating unit, a cooler secondary refrigerant bypass valve, a pipeline and pipeline accessories, wherein the refrigerating unit is used for realizing condensation of water vapor and heavy hydrocarbon in shale gas, the cooler is used for realizing heat exchange between secondary refrigerant and the shale gas, and the cooler secondary refrigerant bypass valve is used for adjusting the flow of the cooler secondary refrigerant.

3. The micro gas turbine generator wellhead shale gas supply device control system of claim 1, wherein: the fine processing control system (11) comprises a differential pressure transmitter, a temperature compensation sensor, a flowmeter, a cable and a cable accessory, wherein the flowmeter is used for acquiring an actual flow value of the shale gas, and the differential pressure transmitter and the temperature compensation sensor are used for correcting the flowmeter.

4. The micro gas turbine generator wellhead shale gas supply device control system of claim 1, wherein: the liquid level control system (9) comprises a liquid level detection element, an automatic blowdown valve, a manual blowdown valve, a one-way valve, a separator and a blowdown pipe, wherein the manual blowdown valve and the automatic blowdown valve are connected in parallel and used for blowdown, and the liquid level detection element is used for realizing real-time monitoring of a liquid level value.

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