CN105890673B - A kind of online wide range dynamic water table-temperature measurement system of underground heat well - Google Patents

Abstract

The invention discloses an online large-scale dynamic water level-temperature measurement system for geothermal wells, which includes a crank-connecting rod piston air pump, a first-fourth two-position three-way solenoid valve, a first-second one-position two-way solenoid valve, a reservoir Gas tank, 1st-2nd differential pressure sensor transmitter, controller with display screen, high temperature resistant gas pilot signal control cable, temperature sensor, temperature transmitter and check valve, high temperature resistant gas pilot signal The control cable and temperature sensor are placed in the measuring tube of the geothermal well; the temperature sensor, the signal line of the high temperature resistant gas conduction signal control cable, the temperature transmitter and the controller are connected in sequence; the first-fourth two-position three-way electromagnetic The electric control terminal of the valve and the 1st-2nd one-position two-way solenoid valve, the signal terminal of the 1st-2nd differential pressure sensor transmitter and the start-up control terminal of the crank connecting rod piston air pump are respectively connected to the interface port of the controller connected. The measurement is carried out by combining pressurization and air extraction. The system has high precision, high temperature resistance, corrosion resistance, durability, vibration resistance, interference resistance, and long-term stable and reliable operation.

Description

An online large-range dynamic water level-temperature measurement system for geothermal wells

technical field

The invention relates to the field of geothermal well measurement, in particular to an online large-range dynamic water level-temperature measurement system for geothermal wells.

Background technique

The significance of online deep dynamic liquid level-temperature measurement of geothermal water wells is to protect the normal operation of submersible electric pumps, avoid damage to submersible electric pumps due to air pumping, and more importantly, to monitor the liquid level and temperature data of geothermal water wells for a long time. The recharge balance after thermal energy utilization provides reliable dynamic monitoring data to prevent land subsidence and protect the hydrogeological environment.

At present, the liquid level gauge of the water measuring well generally adopts the manual or servo motor off-line method, which cannot achieve the purpose of online measurement; the liquid level measurement based on the principle of silicon pressure sensor makes the measurement 100-200 meters due to the bending of the long-distance atmospheric conduit. Long-distance, 100-meter-wide dynamic liquid level changes cannot be realized. Even if it is realized, the diameter of the sensing wire is very large due to the diameter of the air duct, and because of the high temperature of the geothermal water, the online long-term measurement is based on silicon pressure. The liquid level measurement of the principle of the sensor has very strict requirements on the technical requirements of the sensor transmitter's use environment (high temperature), packaging material (titanium alloy) and packaging technology (high temperature waterproof). At the same time, the entire pressure transmitter must be in the standard The measuring pipe (1 inch in diameter) of the geothermal water well is put into the place, so the diameter of the whole pressure sensor transmitter should be less than 15mm. Furthermore, since the pressure sensor transmitter has been placed in high-temperature geothermal water with high salinity for a long time, the casing of the pressure sensor transmitter will quickly foul and block the measurement port, making the pressure sensor transmitter run invalidated.

The fiber grating pressure and temperature measurement method is not applicable to the water level-temperature of online geothermal wells because of the hydrolysis of the fiber cladding and the limitation of temperature resistance (85 degrees Celsius), and because of the cost of the wavelength demodulator. Measurement.

Although the capacitive water level measurement system (two parallel radiation cross-linked polyethylene encapsulated cables) is resistant to geothermal water corrosion and high temperature, due to the interference of the pump working conditions and the long-distance sounding depth of 200 meters, the measurement data Extremely unstable, deep dynamic geothermal well water level measurement cannot be carried out at all.

The maximum accurate range of the bubble water level gauge is 40 meters, and its measurement value is greatly affected by the density and temperature of the medium, so it is not suitable for deep dynamic water level measurement of geothermal wells.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings of the above-mentioned various technical route measurements, and provide an online large-scale dynamic water level of geothermal wells with high temperature resistance, corrosion resistance, vibration and interference resistance, high measurement accuracy, and long-term stable and reliable operation. temperature measurement system.

For this reason, technical scheme of the present invention is as follows:

An online large-scale dynamic water level-temperature measurement system for geothermal wells, including a crank-connecting rod piston air pump, first to fourth two-position three-way solenoid valves, first to second one-position two-way solenoid valves, an air storage tank, and a first 1-2nd differential pressure sensor transmitter, controller with display screen, high temperature resistant air guide signal control cable, temperature sensor, temperature transmitter and 1st-4th one-way valve,

The high temperature-resistant gas conduction signal control cable and the temperature sensor are placed in the measuring tube of the geothermal well;

The temperature sensor, the signal line of the high temperature-resistant gas conduction signal control cable, the temperature transmitter and the controller are connected in sequence;

The electric control terminals of the 1st-4th two-position three-way solenoid valves and the first-second one-position two-way solenoid valves, and the signal terminals of the first-second differential pressure sensor transmitters are connected to the crank The start control ends of the rod-piston air pump are respectively connected to the interface ends of the controller; the controller is controlled through the first and second one-position two-way valves connected to the air storage tank.

The following are all sealed and connected by air guide tube: the air outlet port B1 of the crank-connecting rod piston air pump is connected with the C2 port of the first two-position three-way solenoid valve, and the A2 port of the first two-position three-way solenoid valve is connected with the second two-way solenoid valve. The A3 port of the three-position three-way solenoid valve is connected, the air intake port A1 of the crank-connecting rod piston air pump is connected with the C4 port of the third two-position three-way solenoid valve, and the B4 port of the third two-position three-way solenoid valve is connected with the second two-position three-way solenoid valve. The B3 port of the two-position three-way solenoid valve is connected; the B2 port of the first two-position three-way solenoid valve and the A4 port of the third two-position three-way solenoid valve are respectively connected with the first and fourth one-way valves. In order to receive the atmospheric direction, the C3 port of the second two-position three-way solenoid valve (3) is connected to one port A5 of the first one-position two-way solenoid valve, and the other port B5 of the first one-position two-way solenoid valve is connected to the gas storage One port A6 of the tank is connected, the other port B6 of the gas storage tank is connected to a port A7 of the second one-position two-way solenoid valve, and the other port B7 of the second one-position two-way solenoid valve is connected to the fourth two-position three-way One port A8 of the solenoid valve is connected, and the other port C8 of the fourth two-position three-way solenoid valve is connected with the middle air duct of the high-temperature-resistant air-guiding signal control cable; one port of the first differential pressure sensor transmitter A9 is connected to another port C6 of the gas storage tank, and another port B9 of the first differential pressure sensor transmitter is directly connected to the atmospheric space through the third one-way valve; one port of the second differential pressure sensor transmitter A10 is connected to another port B8 of the fourth two-position three-way solenoid valve, and another port B10 of the second differential pressure sensor transmitter is directly connected to the atmospheric space through the fourth one-way valve.

Preferably, the range of the first differential pressure sensor transmitter is 0-1.4MPa, 0-5V output; the range of the second differential pressure sensor transmitter 10 is 0-500KPa, 0-5V output.

The center of the high temperature-resistant air guiding signal control cable is an air guiding tube, and four signal lines are arranged on the periphery of the air guiding tube.

The water entry depth of the high-temperature-resistant air-conducting signal control cable in the geothermal well measuring pipe is at least 80 meters.

The beneficial effects of the present invention are as follows:

The system of the present invention starts from the purpose of overcoming the technical defects of measuring the large-range water level of geothermal wells in various ways such as pressure, capacitance, conductance, thermal resistance, air bubbles, etc., and invents the online large-range dynamic water level-temperature of geothermal wells with real practical significance Measurement system, the zero point of the system can be automatically corrected, which can completely eliminate the zero point drift error. Through the temperature sensor, it can effectively compensate the liquid specific gravity affected by the temperature change. Therefore, the system has high precision, high temperature resistance, corrosion resistance, vibration resistance, anti-interference, It can run stably and reliably for a long time and is maintenance-free. It is easy to install on site and flexible to operate. It fills the gap of water level monitoring instruments in the dynamic monitoring system of geothermal wells. Because of its simple manufacturing process, the manufacturing cost is low and the cost performance is high, and it can be widely promoted and applied to meet the needs of a comprehensive survey of land hot water resources and dynamic monitoring of geothermal wells.

Description of drawings

Fig. 1 is a gas-electric module and a gas circuit diagram of the measuring system of the present invention;

Fig. 2 is the electronic module and circuit diagram of measuring system of the present invention;

Fig. 3 is the pressure numerical curve of pressure measurement among the present invention;

Fig. 4 is the injection pressure gas circuit diagram of pressurization measurement among the present invention;

Fig. 5 shows the pressure measurement process of pressurization measurement in the present invention;

Fig. 6 shows the air extraction process of air extraction measurement among the present invention;

Fig. 7 shows the pressure measurement process of pumping process among the present invention;

Fig. 8 is the pressure numerical curve of air extraction measurement in the present invention.

Detailed ways

The composition and working process of the online large-scale dynamic water level-temperature measurement system for geothermal wells of the present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1 and Figure 2, the online large-scale dynamic water level-temperature measurement system for geothermal water wells of the present invention includes: crank connecting rod piston air pump 1, first to fourth two-position three-way solenoid valves 2, 3, 4, 8 , 1st-2nd one-position two-way solenoid valve 5, 7, gas storage tank 6, 1st-2nd differential pressure sensor transmitter 9, 10, controller with display screen 11, high temperature resistant gas guide Signal control cable 12, temperature sensor 13, temperature transmitter 14, and first to fourth one-way valves 15a-15d. The high temperature resistant gas conduction signal control cable 12 and the temperature sensor 13 are placed in the measuring pipe of the geothermal water well.

The range of the first differential pressure sensor transmitter 9 is 0-1.4MPa, 0-5V output; the range of the second differential pressure sensor transmitter 10 is 0-500KPa, 0-5V output.

The center of the high-temperature-resistant air-conducting signal control cable 12 is an air-conducting pipe, and four signal lines are arranged on the periphery of the air-conducting pipe. The water entry depth of the high-temperature-resistant air-conducting signal control cable 12 in the geothermal water well measuring pipe is at least 80 meters.

Referring to Fig. 1, in the test system of the present invention, the connection relationship of the gas circuit part is as follows:

The air guide pipe is used to seal the connection as follows: the outlet port B1 of the crank connecting rod piston air pump 1 is connected to the C2 port of the two-position three-way solenoid valve 2, and the A2 port of the first two-position three-way solenoid valve 2 is connected to the two-position three-way solenoid valve. The port A3 in the valve 3 is connected, the intake port A1 of the crank-connecting rod piston air pump 1 is connected to the port C4 in the two-position three-way solenoid valve 4, and the port B4 of the third two-position three-way solenoid valve 4 is connected to the port B4 of the second two-position solenoid valve 4. The B3 port of the three-way solenoid valve 3 is connected;

The air guide pipe is used to seal the connection as follows: the B2 port of the two-position three-way solenoid valve 2 and the A4 port of the two-position three-way solenoid valve 4 are respectively connected with the first and second one-way valves 15a and 15b, and the direction is to receive the atmospheric direction. The C3 port of the two-position three-way solenoid valve 3 is connected with one port A5 of the one-position two-way solenoid valve 5, and the other port B5 of the one-position two-way solenoid valve 5 is connected with one port A6 of the gas storage tank 6, and the gas storage tank The other port B6 of 6 is connected with one port A7 of one-position two-way solenoid valve 7, the other port B7 of one-position two-way solenoid valve 7 is connected with one port A8 of two-position three-way solenoid valve 8, two-position three-way The other port C8 of the solenoid valve 8 is sealed and connected to the middle air guide pipe of the high temperature resistant air guide signal control cable 12 .

The air guide tube is used to seal the connection as follows: one port A9 of the differential pressure sensor transmitter 9 is connected to another port C6 of the gas storage tank 6, and the other port B9 of the differential pressure sensor transmitter 9 passes through the third one-way valve 15c through to atmospheric space.

The following is airtightly connected with the air guide tube: one port A10 of the differential pressure sensor transmitter 10 is connected to the other port B8 of the fourth two-position three-way solenoid valve 8, and the other port B10 of the differential pressure sensor transmitter 10 is passed through The fourth check valve 15d is directly connected to the air space.

Referring to Fig. 2, in the test system of the present invention, the connection relation of circuit part is as follows:

Wherein, the temperature sensor 13, the signal line of the high temperature-resistant gas conduction signal control cable 12, the temperature transmitter 14, and the controller 11 with a display screen are connected in sequence;

Among them, the start control terminal W1 of the crank connecting rod piston air pump 1, the electric control terminal W2 of the two-position three-way solenoid valve 2, the electric control terminal W3 of the two-position three-way solenoid valve 3, the electric control terminal W4 of the two-position three-way solenoid valve 4, A two-way solenoid valve 5 electronic control terminal W5, a two-way solenoid valve 7 electric control terminal W7, a two-position three-way solenoid valve 8 electronic control terminal W8, the signal terminal X9 of the differential pressure sensor transmitter 9, the differential pressure The signal terminals X10 of the sensor transmitter 10 are respectively connected to the interface terminals of the controller 11 with a display screen.

The working process of the above measurement system is as follows:

Put the high-temperature-resistant gas-conducting signal control cable 12 into the geothermal well measuring pipe, and the high-temperature-resistant gas-conducting signal control cable 12 has a depth of at least 80 meters into the water.

Referring to Figure 4, under the control of the controller 11, C2 of the two-position three-way solenoid valve 2 is connected to A2 of the two-position three-way solenoid valve 2, and A3 of the two-position three-way solenoid valve 3 is connected to the two-position three-way solenoid valve. C3 of 3 conducts, A4 of 2-position 3-way solenoid valve 4 conducts with C4 of 2-position 3-way solenoid valve 4, A5 of 1-position 2-way solenoid valve 5 conducts with B5 of 1-position 2-way solenoid valve 5, A7 and B7 of one-way two-way solenoid valve 7 are disconnected, crank-connecting-rod piston air pump 1 is started, and the compressed air flows through B1, C2, A2, A3, C3, A5, B5, and A6 in sequence to form high-pressure air in the air storage tank 6. room. Referring to Fig. 5, the controller 11 measures the pressure value (subtracting an atmospheric pressure difference) of the gas storage tank 6 in real time through the differential pressure sensor transmitter 9. When the value is 1.3MPa, under the control of the controller 9, Close the crank connecting rod piston air pump 1, close the one-position two-way solenoid valve 5, turn on one-point two-way solenoid valve 7, and conduct the A8 and C8 of the two-position three-way solenoid valve 8, and the compressed air is controlled by the high-temperature-resistant air-conducting signal The air guide pipe of cable 12 is injected into geothermal water well water. According to the principle of fluid mechanics, when the air duct emits bubbles to the hot water body, the pressure of the air storage chamber 6 is greater than the pressure of the hot water body, and only when the air-water exchange surface is located at the mouth of the air duct, the pressure in the air storage chamber 6 will be higher than that of the hot water body. The pressure is just equal to the hydrostatic pressure at the mouth of the air guide tube. By continuously measuring the pressure change in the high-pressure gas storage chamber 6 (the pressure slowly decreases with time), the controller 11 continuously samples the pressure value in the high-pressure gas storage chamber, which can be measured from It refers to the pressure during the period from when the air pump is stopped to when water and air enter the trachea.

See Figure 3, take its average value as P ₉ according to its change curve, according to γ is the density of geothermal water, and P ₉ is the differential pressure value minus the atmospheric pressure. Therefore, the above formula is the actual water entry depth value H ₁ of the gas guide cable in the geothermal water well measured by pressurization, and the unit is _mH2O (meter water column).

Referring to Fig. 6, when the real-time pressure value measured by the controller 11 through the differential pressure sensor transmitter 9 drops rapidly, under the instruction of the controller 11, the ports C2 and B2 of the two-position three-way solenoid valve 2 are connected, and the two-position The ports C3 and B3 of the three-way solenoid valve 3 are connected; A7 and B7 are connected, and the ports C8 and A8 of the two-position three-way solenoid valve 8 are connected, and the crank-connecting rod piston air pump 1 is turned on, and the pumping operation is performed.

Referring to Fig. 7, the controller 11 measures the pressure value of the gas storage tank 6 in real time (minus an atmospheric pressure difference) through the differential pressure sensor transmitter 9. Under control, the crank-connecting rod piston air pump 1 is turned off, the one-position two-way solenoid valve 7 is turned off, and the port C8 of the two-position three-way solenoid valve 8 is connected to the port B8, and the differential pressure sensor transmitter 10 starts to measure.

Referring to Figure 8, take its average value P ₁₀ according to its value change curve, and according to the principle of fluid mechanics, it can be calculated:

Where: γ is the density of geothermal water;

P ₁₀ is the difference of subtracting the atmospheric pressure;

L is the length of the airway.

The above formula is: the actual water entry depth value H ₂ of the air guide cable in the geothermal water well measured by means of air extraction (pressure guidance), and the unit is mH ₂ O (meter water column).

The measurement results of the pressurization method and the air extraction and pressure guidance method are calculated according to the following formula to obtain the average value H ₀ of the actual water penetration depth of the gas guide cable in the geothermal well, and the unit is mH ₂ O (meter water column).

Further, through the following formula:

H _shuiwei ＝L ₀ -H ₀

in:

L ₀ is the length of the cable lowered from the geothermal water wellhead;

H _shuiwei is the water level value from the geothermal water wellhead to the geothermal water surface.

The precise water level value H _shuiwei of this measurement is obtained. At the same time, the temperature value of the geothermal well water can be measured by the temperature sensor 13 and the temperature transmitter 14 .

Claims (5)

1. An on-line large-scale dynamic water level-temperature measurement system for geothermal wells, characterized in that: it includes a crank-connecting rod piston air pump (1), the 1st-4th two-position three-way solenoid valve (2, 3, 4, 8) , 1st-2nd one-position two-way solenoid valve (5, 7), gas storage tank (6), 1st-2nd differential pressure sensor transmitter (9, 10), controller with display screen (11), high temperature resistant air guide signal control cable (12), temperature sensor (13), temperature transmitter (14) and 1st-4th one-way valves (15a-15d), The high-temperature-resistant air-conducting signal control cable (12) and the temperature sensor (13) are placed in the measuring tube of the geothermal well; The temperature sensor (13), the signal line of the high-temperature-resistant gas conduction signal control cable (12), the temperature transmitter (14) and the controller (11) are connected in sequence; The electric control terminals (W2, W3, W4, W8, W5, W7) and the signal terminals (X9, X10) of the first-second differential pressure sensor transmitters (9, 10) and the starting control terminal (W1) of the crank connecting rod piston air pump (1) respectively connected to the interface ports of the controller (11); the controller (11) is controlled through the first and second one-position two-way valves (5, 7) connected to the gas storage tank (6); The following are all sealed and connected with the air guide tube: the air outlet port B1 of the crank-connecting rod piston air pump (1) is connected to the C2 port in the first two-position three-way solenoid valve (2), and the first two-position three-way solenoid valve (2) ) port A2 in the second two-position three-way solenoid valve (3) is connected to port A3 in the second two-position three-way solenoid valve (3), and the intake port A1 of the crank-connecting rod piston air pump (1) is connected to the port A1 in the third two-position three-way solenoid valve (4). The C4 port is connected, and the B4 port of the third two-position three-way solenoid valve (4) is connected with the B3 port of the second two-position three-way solenoid valve (3); the B2 port of the first two-position three-way solenoid valve (2) port, the A4 port of the third two-position three-way solenoid valve (4) is respectively connected with the first and second one-way valves (15a, 15b), and its direction is to receive the atmospheric direction, and the second two-position three-way solenoid valve (3 ) port C3 is connected to one port A5 of the first one-position two-way solenoid valve (5), and the other port B5 of the first one-position two-way solenoid valve (5) is connected to one port A6 of the gas storage tank (6) , the other port B6 of the gas storage tank (6) is connected to a port A7 of the second one-position two-way solenoid valve (7), and the other port B7 of the second one-position two-way solenoid valve (7) is connected to the fourth two-way A port A8 of the three-position three-way solenoid valve (8) is connected, and another port C8 of the fourth two-position three-way solenoid valve (8) is connected with the middle air duct of the high temperature resistant air conduction signal control cable (12); One port A9 of the first differential pressure sensor transmitter (9) is connected to another port C6 of the gas storage tank (6), and another port B9 of the first differential pressure sensor transmitter (9) passes through the third The one-way valve (15c) is directly connected to the atmospheric space; one port A10 of the second differential pressure sensor transmitter (10) is connected with the other port B8 of the fourth two-position three-way solenoid valve (8), and the second pressure The other port B10 of the differential sensor transmitter (10) is directly connected to the air space through the fourth check valve (15d). 2. The online large-range dynamic water level-temperature measurement system for geothermal wells according to claim 1, characterized in that: the range of the first differential pressure sensor transmitter (9) is 0-1.4MPa, 0-5V output. 3. The geothermal well online large-range dynamic water level-temperature measurement system according to claim 1, characterized in that: the second differential pressure sensor transmitter 10 has a range of 0-500KPa and an output of 0-5V. 4. The online large-range dynamic water level-temperature measurement system for geothermal wells according to claim 1, characterized in that: the center of the high-temperature-resistant air-guiding signal control cable (12) is an air-guiding pipe, and the periphery of the air-guiding pipe is provided with Four signal lines. 5. The online large-range dynamic water level-temperature measurement system for geothermal wells according to claim 1, characterized in that: the water penetration depth of the high temperature-resistant gas-conducting signal control cable (12) in the geothermal well measuring tube is at least 80 Meter.