High-temperature geothermal fluid sampling device and method

Abstract

The invention relates to the technical field of geothermal gas collection, in particular to a high-temperature geothermal fluid sampling device and method. The sampling device comprises a sampling unit, a monitoring unit and a gas collecting unit, wherein the sampling unit comprises a gas collecting hood, a movable rod piece, a waterproof breathable film and a transmission pipeline; the monitoring unit comprises a temperature sensor, a gas flowmeter and a film gauge; the gas collection unit comprises a tail gas collector, a sampler and a power source. The sampling device is simple in overall structure and good in sealing performance, and is provided with a power source, so that the sampling requirements of different types of samples can be met, and the sampling efficiency can be improved on the basis of ensuring the sampling purity. The sampling method is simple to operate, and the accuracy of the sample collection time is improved by innovating a sampling time calculation formula.

Description

Technical Field

[0001] The present invention relates to the technical field of geothermal gas collection, and particularly relates to a high-temperature geothermal fluid sampling device and method. Background Art

[0002] The geothermal gas escaping from high-temperature geothermal fluid is the most intuitive manifestation form of geothermal resources in nature and is also the main body of geothermal energy development and utilization. Its chemical composition and isotope composition carry information about the materials and energy inside the earth, and play an important role in indicating the geothermal geological conditions, geothermal exploration and development of geothermal systems. At the same time, it is also closely related to engineering problems and environmental protection problems in the process of geothermal energy exploitation, such as scaling, corrosion and greenhouse gas emissions, etc. To conduct in-depth research on geothermal gas, it is necessary to systematically collect hot spring gas first, make the collection method as simple as possible and the collection process efficient, and ensure that the collected gas is not contaminated to ensure the accuracy of the gas sample test results.

[0003] During the process of collecting geothermal gas in the wild, some problems are often encountered. For example: ①. Regarding the problem that the outlet of geothermal gas is uncertain, since the gas collection hood of the traditional collection device cannot be adjusted in size, it is impossible to collect in a timely and efficient manner; ②. Regarding the problem that the escape flow rate of geothermal gas is small and the escape rate is slow, the current existing technology adds a suction syringe to accelerate the escape gas flow rate, but the suction syringe has problems such as slow suction efficiency, poor airtightness and troublesome operation; ③. Regarding the problem of collecting different types of gases, the traditional collection device cannot replace the sampler as needed; ④. There are serious deficiencies in the time limit for the process of collecting geothermal gas in the existing technology. In particular, there is no clear standard and description for whether the air in the collection device is exhausted and whether the geothermal gas collected in the sampler meets the requirements. If the time for exhausting air and completing collection is not clear, it may pollute the collected geothermal gas due to the incomplete exhaustion of the air in the device, and it may not be able to meet the subsequent test analysis due to the sampler not collecting enough geothermal gas.

[0004] In summary, there is an urgent need for a sampling device and sampling method with a simple structure and suitable for high-temperature geothermal fluid sampling to solve the problems existing in the prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a sampling device with a simple structure and suitable for high-temperature geothermal fluid sampling. The specific technical solutions are as follows:

[0006] A high-temperature geothermal fluid sampling device, comprising a sampling unit, a monitoring unit and a gas collection unit; the sampling unit includes a gas collection hood, a moving rod, a waterproof and breathable membrane and a transmission pipeline, and the gas collection hood is arranged at the sampling point; the moving rod is connected to the gas collection hood and can adjust the relative position between the gas collection hood and the sampling point; the intake end of the transmission pipeline is adjustably connected to the gas collection hood; the waterproof and breathable membrane is arranged at the intake end of the transmission pipeline;

[0007] The monitoring unit includes a temperature sensor, a gas flow meter and a thin film gauge. The temperature sensor is arranged inside the gas collection hood, the gas flow meter is arranged inside the transmission pipeline, and the thin film gauge is arranged on the transmission pipeline;

[0008] The gas collection unit includes an exhaust gas collector, a sampler and a power source. The exhaust gas collector is arranged at the end of the transmission pipeline for collecting exhaust gas, and the sampler is arranged on the transmission pipeline or at the end of the transmission pipeline for sampling the gas output by the transmission pipeline; the power source is arranged on the transmission pipeline.

[0009] In the present invention, the high-temperature geothermal fluid sampling device includes a sampling unit, a monitoring unit and a gas collection unit; the sampling unit includes a gas collection hood, a moving rod, a waterproof and breathable membrane and a transmission pipeline; the monitoring unit includes a temperature sensor, a gas flow meter and a thin film gauge; the gas collection unit includes an exhaust gas collector, a sampler and a power source. The overall structure of the sampling device is concise, with good sealing performance, and is equipped with a power source, which can not only meet the sampling requirements of different types of samples, but also improve the sampling efficiency on the basis of ensuring the sampling purity.

[0010] Preferably, the sampling unit further includes umbrella wings detachably arranged on the gas collection hood and capable of expanding the covering range of the gas collection hood. The umbrella wings include a single or multiple nested frustum-shaped single pieces. The gas collection hood is equipped with umbrella wings to expand the area of the gas collection hood opening, facilitating the more efficient collection of gas by the gas collection hood, improving the gas collection efficiency, and due to the support of the umbrella wings, the moving lever controls the gas collection hood to be more stable during the sliding process.

[0011] Preferably, the intake end of the transmission pipeline is adjustably connected to the gas collection hood by a telescopic hose. The telescopic hose is adjustable, facilitating the adjustment of the relative position between the gas collection hood and the sampling point to meet the sampling requirements.

[0012] Preferably, the measuring range of the thin-film gauge is 0.1 - 1000 Torr, and the accuracy is 0.15% of the reading; the power source is a dual-purpose pumping and drawing air pump, and when working, the output air pressure is 90 kPa - 120 kPa, and the flow rate is 5 cm / s. The thin-film gauge adopts a high-precision thin-film gauge, which can accurately record the air pressure in the sampler, and is convenient for subsequent direct detection after remarks. The power source adopts a dual-purpose pumping and drawing air pump, which simplifies the device circuit and the components of the device. Compared with the traditional air extraction syringe, the integration degree of the sampling device is higher, reducing unnecessary labor and energy, and at the same time reducing the risk of insufficient air tightness of the device due to loose connections.

[0013] Preferably, the sampler is a vacuum gas collection bag, and the vacuum gas collection bag is connected to the pipe section between the thin-film gauge and the tail gas collector in the transmission pipeline. The sampler adopts a vacuum gas collection bag, which can effectively investigate the concentration of carbon dioxide and 13 C and 14 C isotopes in geothermal fluid.

[0014] Preferably, the sampler includes a fixed frame and a copper pipe. The copper pipe is arranged on the fixed frame, and both the inlet end and the outlet end of the copper pipe are located outside the fixed frame. The inlet end of the copper pipe is connected to the pipe section with a thin-film gauge in the transmission pipeline, and the outlet end of the copper pipe is connected to the pipe section with a tail gas collector in the transmission pipeline; both between the inlet end of the copper pipe and the pipe section and between the outlet end of the copper pipe and the pipe section are fixed by valves and / or pipe clamps. The sampler uses a copper pipe for sampling, which can effectively study inert gases in geothermal fluid, such as helium, neon, etc.

[0015] Preferably, the sampler includes a sampling glass bottle and a bent pipe. The sampling glass bottle is filled with hot spring water and inverted in the tail gas collector. One end of the bent pipe extends into the sampling glass bottle, and the other end is connected to or inserted into the end of the transmission pipeline. The sampler adopts a sampling glass bottle, which can effectively analyze the components and concentration of the gas contained in geothermal fluid.

[0016] The present invention also discloses a high-temperature geothermal fluid sampling method, which uses the above-mentioned high-temperature geothermal fluid sampling device for sampling, and includes the following steps:

[0017] Step 1: Measure the ambient temperature through the temperature sensor on the air collection hood; select an air collection hood with a matching umbrella wing size according to the escape range of the bubbles in the water at the sampling point; operate the moving lever to place the air collection hood at the bubble escape position;

[0018] Step 2: Wait for the air collection hood to be stationary on the water surface, observe the readings of the gas flow meter and the temperature sensor. When the gas flow meter and the temperature sensor start to display readings, turn on the power source and draw the geothermal gas to be collected until the air existing in the high-temperature geothermal fluid sampling device is exhausted;

[0019] Step 3: Select the corresponding sampler for sampling according to requirements.

[0020] Preferably, the sampling time Time for sampling in Step 3 is determined by the following formula:

[0021]

[0022] Where: v is the flow rate of geothermal gas; A is the cross-sectional area of the transmission pipeline; P is the pressure of the gas at the carrier cross-section; T is the absolute temperature with a value of 273.15K; T 0 is the initial temperature of the geothermal gas; ω is the relationship between the cooling temperature and the gas flow rate; V 0 is the volume of the sampler.

[0023] Preferably, the sampling time Time is determined by the following steps:

[0024] Step a1: Collect the data set of the gas temperature cooling with time during the field geothermal gas sampling process;

[0025] Step a2: Analyze and process the data set collected in Step a1 to obtain the value of the constant k for each group of data, and determine the value of the constant k by calculating the mean and variance;

[0026] Step a3: Divide the cooling process of the geothermal gas from the gas collecting hood to the sampler into N segments according to time, and based on the value of the constant k determined in Step a2, introduce Newton's cooling formula to calculate the temperature T of the geothermal gas in each time period during the cooling process i ;

[0027] Step a4: Based on the temperature T of each time period calculated in Step a3 during the cooling process i , combine with the pipeline gas flow formula to obtain Formula 1, and calculate the gas flow rate Q output by the geothermal gas in the i-th time period during the cooling process through Formula 1 冷却 ;

[0028] Step a5: Based on the cooling temperature T obtained in Step a3 i and the gas flow rate Q obtained in Step a4 冷却 , fit the relationship ω between the cooling temperature and the gas flow rate;

[0029] Step a6: Based on the relationship ω fitted in Step a5, combine with the volume of the sampler to obtain Formula 2, and calculate the time required for the sampling process through Formula 2;

[0030] Formula 1:

[0031]

[0032] Formula 2:

[0033]

[0034] Where: Q 冷却 is the gas flow rate output by the geothermal gas during the o-th period of the cooling process; T i-1 is the temperature corresponding to the (i - 1)-th stage during the cooling process, where i is a natural number greater than or equal to 1 and less than N; T m is the medium temperature, i.e., the atmospheric temperature; Tf is the cooling time used.

[0035] Preferably, before sampling in the third step, it is necessary to determine whether the inside of the high-temperature geothermal fluid sampling device is emptied, and the determination method is as follows:

[0036] Step b1: Calculate the gas flow rate output by the geothermal gas during the i-th period of the cooling process using Formula 1:

[0037]

[0038] Step b2: Calculate the total gas flow rate output by the geothermal gas during the entire cooling process using the following formula:

[0039]

[0040] Step b3: Make a judgment. If Q 总气流量 is greater than or equal to the total volume V a of the high-temperature geothermal fluid sampling device, then directly enter the subsequent sampling stage; if Q 总气流量 is less than the total volume V a of the high-temperature geothermal fluid sampling device, then extend the evacuation time δT, and δT is calculated using the following formula:

[0041]

[0042] Where: T Tf is the temperature of the geothermal gas after cooling.

[0043] Applying the sampling method of the present invention, the operation is simple, and through the innovative sampling time calculation formula, the accurate sampling time can be obtained, the accuracy of the sample collection time is improved, and it is ensured that the collected geothermal gas can better meet the subsequent experimental requirements.

[0044] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The following will refer to the drawings for a further detailed description of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0046] Figure 1 It is a schematic structural diagram of a high-temperature geothermal fluid sampling device in which a vacuum gas collection bag is used as the sampler in the embodiment;

[0047] Figure 2 is Figure 1 a schematic structural diagram of the moving rod in

[0048] Figure 3 is Figure 1 a schematic structural diagram of the umbrella wing in

[0049] Figure 4 is Figure 1 a schematic structural diagram of the gas collection hood in

[0050] Figure 5 It is a schematic structural diagram of a high-temperature geothermal fluid sampling device in which a copper pipe is used as the sampler in the embodiment;

[0051] Figure 6 It is a schematic structural diagram of a high-temperature geothermal fluid sampling device in which a sampling glass bottle is used as the sampler in the embodiment;

[0052] Among them, 1. Gas collection hood, 1.1 External thread connection part, 2. Moving rod, 2.1 Ring part, 2.2 Handheld part, 3. Waterproof and breathable membrane, 4. Transmission pipeline, 5. Temperature sensor, 6. Gas flowmeter, 7. Film gauge, 8. Tail gas collector, 9. Sampler, 9.1 Fixed frame, 9.2 Copper pipe, 9.3 Sampling glass bottle, 9.4 Elbow pipe, 10. Power source, 11. Umbrella wing, 12. Telescopic hose, 13. Pipe clamp, 14. Hot spring water. Detailed implementation manners

[0053] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways defined and covered by the claims.

[0054] Embodiment:

[0055] A high-temperature geothermal fluid sampling device, see Figures 1-6 , including a sampling unit, a monitoring unit and a gas collection unit. The sampling unit includes a gas collection hood 1, a moving rod 2, a waterproof and breathable membrane 3 and a transmission pipeline 4. The monitoring unit includes a temperature sensor 5, a gas flowmeter 6 and a film gauge 7. The gas collection unit includes a tail gas collector 8, a sampler 9 and a power source 10. The detailed structure is as follows:

[0056] When the sampler 9 is a vacuum gas collection bag, it can effectively investigate the concentration of carbon dioxide and 13 C and 14 C isotopes, such as Figure 1 shown:

[0057] The gas collection hood 1 is arranged at the sampling point; the moving rod 2 is connected to the gas collection hood 1 and can adjust the relative position between the gas collection hood and the sampling point. In this embodiment, the moving rod 2 is as shown in Figure 2 . It includes an annular member 2.1 and a hand-held member 2.2. The annular member can be sleeved on the gas collection hood, and the hand-held member is connected to the annular member, facilitating the sampler to hold. Further preferably, the adjustable length range of the hand-held member is 100 cm - 150 cm, and the annular member is a ring with a diameter of 10 cm, which can be sleeved on the gas collection hood. The operator holds the moving lever to control the movement of the gas collection hood and fix the sampling position of the gas collection hood.

[0058] In addition, the sampling unit further includes a wing 11 detachably arranged on the gas collection hood 1 and capable of expanding the covering range of the gas collection hood 1. The wing 11 includes a single or multiple nested frustum-shaped single pieces, as shown in Figure 3 . The wing is preferably made of plastic material, which is light, easy to float, convenient to fold up, and can be made into a hollow frustum with an open lower end diameter of 20 cm, 25 cm, 30 cm and an open upper end diameter of 10 cm, which can be sleeved on the gas collection hood.

[0059] This can avoid the problem that when the hot spring water is turbid or the hot spring is bottomless, the bubbling air outlet is invisible and gas cannot be effectively collected. By observing the situation of bubbles escaping from the water surface, the gas collection hood is moved using the moving lever, and the gas collection hood is controlled to be fixed directly above the bubbling opening. Moreover, the large-range covering wing can ensure large-area coverage of bubbles, which can improve the efficiency of collecting geothermal gas. And under the control of the moving lever, it can be ensured that the collection hood will not float up and cause air to enter.

[0060] A temperature sensor 5 is attached to the gas collection hood for measuring the temperature when geothermal gas escapes.

[0061] The intake end of the transmission pipeline 4 is adjustably connected to the gas collection hood 1. In this embodiment, it is preferably that the intake end of the transmission pipeline 4 is adjustably connected to the gas collection hood 1 by a telescopic hose 12. The telescopic hose can be connected to the gas collection hood and the transmission pipeline by one of the methods such as bonding, screw with a sealing ring, and pipe clamp 13, as shown in Figure 4 . It is shown that the upper end of the gas collection hood is provided with an external thread connection part 1.1, which is convenient for installation and disassembly and can ensure meeting the requirements of sealed connection.

[0062] The waterproof and breathable membrane 3 is provided at the air inlet end of the transmission pipeline 4. The waterproof and breathable membrane is used to prevent geothermal water from flowing in the transmission pipeline and damaging the equipment or instruments on the pipeline. In this embodiment, it is further preferred that the breathable and waterproof membrane is made of polytetrafluoroethylene, which is almost insoluble in all solvents and has the characteristic of high temperature resistance. The waterproof and breathable membrane is arranged between the transmission conduits, which can effectively solve the problem that geothermal water floods into the device due to improper control of the air pump.

[0063] The gas flowmeter 6 is arranged in the transmission pipeline 4 and is used to accurately measure the gas flow rate in the transmission pipeline. The thin film gauge 7 is arranged on the transmission pipeline 4. The measuring range of the thin film gauge is 0.1 - 1000 Torr, and the accuracy is 0.15% of the reading. The high-precision thin film gauge is adopted, which can accurately measure the pressure of the collected gas. Combining with the volume of the sampler, the amount of the collected gas can be obtained.

[0064] The tail gas collector 8 is arranged at the end of the transmission pipeline 4 for collecting tail gas. The sampler 9 is arranged on the transmission pipeline 4 for sampling the gas output by the transmission pipeline 4. The power source 10 is arranged on the transmission pipeline 4. The end of the transmission pipeline 4 leads into the tail gas collector formed by the hot spring water 14, and the redundant gas in the sampling device is discharged into the tail gas collector, which can not only avoid the pollution caused by the emission of some geothermal gases into the atmosphere, but also prevent the atmosphere from flowing back into the device from the end of the transmission pipeline 4, causing air pollution, and ensure the purity of the geothermal gas collected in the device.

[0065] Here, the power source is a dual-purpose pumping and sucking air pump. When working, the output air pressure is 90 kPa - 120 kPa, and the flow rate is 5 cm / s. It is further preferred that the dual-purpose pumping and sucking air pump is directly connected to the transmission pipeline, making the device circuit simple, simplifying the components of the device. Compared with the traditional air extraction syringe, the integration degree of the sampling device is higher, reducing unnecessary labor and energy, and at the same time reducing the risk of insufficient airtightness of the device due to loose connections.

[0066] Such as Figure 1 , the vacuum gas collection bag is connected to the pipe section of the transmission pipeline 4 between the thin film gauge 7 and the tail gas collector 8. Further preferably, the transmission pipeline 4 is a silica gel pipe with an inner hole diameter of 20 mm × an outer hole diameter of 24 mm. The front end of the transmission pipeline 4 is connected to the telescopic hose through a pipe clamp 13 (further preferably a micro pipe clamp); the rear end is connected to the sampler through a pipe clamp. The aperture matches that of the dual-purpose pumping and sucking air pump, ensuring good airtightness at the joints of the entire sampling device.

[0067] When the sampler uses a copper pipe, it can effectively study the inert gases in geothermal fluids, such as helium, neon, etc., such as Figure 5As shown, the sampler 9 includes a fixed frame 9.1 and a copper pipe 9.2. The copper pipe 9.2 is arranged on the fixed frame 9.1, and both the air inlet end and the air outlet end of the copper pipe 9.2 are located outside the fixed frame 9.1. The air inlet end of the copper pipe 9.2 is communicated with the pipe section of the transmission pipeline 4 where the thin film gauge 7 is provided, and the air outlet end of the copper pipe 9.2 is communicated with the pipe section of the transmission pipeline 4 where the tail gas collector 8 is provided; both between the air inlet end of the copper pipe 9.2 and the pipe section and between the air outlet end of the copper pipe 9.2 and the pipe section are fixed by valves and / or pipe clamps 13.

[0068] When the sampler uses a sampling glass bottle, it can effectively analyze the components and concentrations of the gases contained in the geothermal fluid. For details, see Figure 6 As shown, the sampler 9 includes a sampling glass bottle 9.3 and a bent pipe 9.4. The sampling glass bottle 9.3 is filled with hot spring water and inverted in the tail gas collector 8. One end of the bent pipe 9.4 extends into the sampling glass bottle 9.3, and the other end is connected to or inserted into the end of the transmission pipeline 4.

[0069] Using the high-temperature geothermal fluid sampling device of this embodiment for sampling specifically includes:

[0070] Step 1: Measure the ambient temperature through the temperature sensor on the air hood; select an air hood with a matching umbrella wing size according to the escape range of the bubbles in the water at the sampling point; operate the moving lever to place the air hood at the bubble escape position;

[0071] Step 2: Wait for the air hood to be stationary on the water surface, observe the readings of the gas flowmeter and the temperature sensor. When the gas flowmeter and the temperature sensor start to display readings, turn on the power source and extract the geothermal gas to be collected until the air existing in the high-temperature geothermal fluid sampling device is exhausted;

[0072] Step 3: Select the corresponding sampler for sampling according to the requirements.

[0073] The sampling time Time for sampling in the third step is determined by the following formula:

[0074]

[0075] Where: v is the flow rate of the geothermal gas, and its unit is cm / s; A is the cross-sectional area of the transmission pipeline in cm 2 ; P is the pressure of the gas at the carrier cross-section, and its unit is MPa; T is the absolute temperature with a value of 273.15, and its unit is K; T 0 is the initial temperature of the geothermal gas, and its unit is °C; ω is the relationship between the cooling temperature and the gas flow rate; V 0 is the volume of the sampler, and the unit is cm 3 .

[0076] The sampling time Time during the sampling of the escaping gas from the high-temperature geothermal fluid is obtained by the following steps:

[0077] Step a1: Collect the dataset of the gas temperature cooling with time during the field geothermal gas sampling, as shown in Table 1;

[0078] Step a2: Analyze and process the dataset collected in step a1 to obtain the value of the constant k for each group of data, as shown in Table 1; and determine the value of the constant k by calculating the mean and variance;

[0079] Table 1 Dataset of the gas temperature cooling with time during the field geothermal gas sampling and the value of the constant k

[0080]

[0081]

[0082]

[0083] The analysis and processing in step a2 include:

[0084] Calculating the mean and variance, specifically: Solve the collected dataset of the temperature cooling to obtain its mean and variance, and analyze the rationality of the determined value of the constant k. Its expression is as follows:

[0085]

[0086] Based on the value of the constant k in Table 1, the mean of the constant k is 0.01396, and the standard deviation is 0.0001439. The mean value of the constant k is reliable. Therefore, in the calculation process of this embodiment, the value of the constant k is taken as 0.01396.

[0087] Step a3: Divide the cooling process of the geothermal gas from the gas collection hood to the sampler into N segments according to time, and based on the value of the constant k determined in step a2, introduce Newton's cooling formula to calculate the temperature T of the geothermal gas in the i-th time period during the cooling process i , where i is a natural number greater than or equal to 1 and less than N;

[0088] Introduce Newton's cooling formula as follows:

[0089]

[0090] Where: T i (0) is the initial temperature of the i-th time period;

[0091] By integrating, we get:

[0092]

[0093] Substitute the value of the constant k determined in step a2 to obtain:

[0094]

[0095] Step a4. Based on the temperature T during the cooling process calculated in step a3 i , combined with the pipeline gas flow formula, formula one is obtained. Through formula one, the gas flow rate Q output by the geothermal gas during the i-th period of the cooling process can be calculated 冷却 ;

[0096] Step a5. Based on the cooling temperature T obtained in step a3 i and the gas flow rate Q obtained in step a4 冷却 , fit the relationship ω between the cooling temperature and the gas flow rate;

[0097] In this embodiment, ω = -2126.358034 * e 0.000013*x + 2126.357472;

[0098] where: x is the reduced temperature, with the unit of °C, that is, x = T Tf - T 0 ; e is the natural constant;

[0099] Step a6. Based on the relationship fitted in step a5, combined with the volume of the sampler, formula two is obtained. Through formula two, the time required for the sampling process can be calculated.

[0100] Formula one:

[0101]

[0102] Formula two:

[0103]

[0104] where: Q 冷却 is the gas flow rate output by the geothermal gas during the i-th period of the cooling process; T i-1 is the temperature corresponding to the (i - 1)-th section during the cooling process; v is the flow velocity of the geothermal gas, with the unit of cm / s; A is the cross-sectional area of the transmission pipeline, with the unit of cm 2 ; P is the pressure of the gas at the current-carrying cross-section, with the unit of MPa; T is the absolute temperature taking the value of 273.15, with the unit of K; T 0 is the initial temperature of the geothermal gas, with the unit of °C; V 0 is the volume of the sampler, with the unit of cm 3 ; T m is the medium temperature, that is, the atmospheric temperature, with the unit of °C; Tf is the cooling time, with the unit of s.

[0105] In step a3, the cooling time is divided into N segments as shown in Table 2:

[0106] Table 2 Detailed data table of the cooling time divided into N segments

[0107]

[0108]

[0109] Substitute into the pipeline gas flow formula as follows:

[0110]

[0111] Before sampling in step three, it is necessary to determine whether the inside of the high-temperature geothermal fluid sampling device is emptied, and the determination method is as follows:

[0112] Step b1: Use the following formula to calculate the flow rate output by the geothermal gas in the i-th time period during the cooling process:

[0113]

[0114] Step b2: Use the following formula to calculate the total gas flow rate that the geothermal gas can output during the entire cooling process:

[0115]

[0116] Step b3: Make a judgment. If Q 总气流量 is greater than or equal to the total volume V of the high-temperature geothermal fluid sampling device a , then directly enter the subsequent sampling stage; if Q 总气流量 is less than the total volume V of the high-temperature geothermal fluid sampling device a , then extend the evacuation time δT, and δT is calculated by the following formula:

[0117]

[0118] Where: T Tf is the temperature after the geothermal gas is cooled, and its unit is °C.

[0119] The specific sampling operations of three different samplers are as follows:

[0120] When the research purpose of collecting gas samples is to investigate the concentration of carbon dioxide in the geothermal fluid and 13 C and 14When using a C isotope, that is, when the sampler is a vacuum gas collection bag with a capacity of 50 ml, first close the air outlet of the vacuum gas collection bag, and calculate the time required for the geothermal gas to fill the vacuum gas collection bag under this geological condition through Formula 2. When the calculated time is reached, the sampling work is completed. Close the gate of the air inlet of the vacuum gas collection bag. The two ends of the vacuum gas collection bag are equipped with spiral gates. When the knob is tightened, the gas collection bag will form a seal. Observe the reading of the diaphragm gauge and record the pressure in the vacuum gas collection bag at this time. After the collection is completed, remove the sampler, note the recorded gas pressure on each sampler, and store it at room temperature for inspection.

[0121] When the research purpose of collecting gas samples is to study the content of inert gases in geothermal fluids and their effects on geothermal fluids, that is, when the sampler is a copper tube, first close the air outlet end of the copper tube through the fixed frame, calculate the time required for the copper tube to collect geothermal gas, and close the air inlet ends of both ends of the copper tube through the fixed frame. If there is no gap between the two outer parts of the clip, the clip is properly closed. When the machining gap between the sealing surfaces is the same as the wall thickness of the copper tube (that is, the two walls are forced to be combined to half of the original thickness), the copper tube will form a seal and the device sampling is completed. Observe the reading of the diaphragm gauge and record the pressure in the copper tube at this time. After the collection is completed, remove the sampler, note the recorded gas pressure on each sampler, and store it at room temperature for inspection.

[0122] When the research purpose of collecting gas samples is to simply analyze the gas composition and concentration in geothermal fluids, that is, when the sampler is a sampling glass bottle, first rinse the sampling glass bottle with hot spring water 3 - 5 times, and then invert the sampling glass bottle filled with hot spring water in the tail gas collector. The volume of the sampling glass bottle is 100 ml. When the hot spring water in the sampling glass bottle is drained to 10 ml left, calculate the required time, and the device sampling work is completed. Plug the wooden valve of the sampling glass bottle in the tail gas collector. When the wooden valve is tightened, the sampling glass bottle forms a seal. Observe the reading of the diaphragm gauge and record the pressure in the sampling glass bottle at this time. After the collection is completed, remove the sampler, note the recorded gas pressure on each sampler, and store it at room temperature for inspection.

[0123] Applying the technical solution of this embodiment, the effects are as follows: ①. The collection hood of the high-temperature geothermal fluid sampling device realizes the expansion of the hood opening area through umbrella wings of different specifications, facilitating the more efficient collection of gas by the collection hood, improving the gas collection efficiency, and due to the support of the umbrella wings, the moving lever controls the collection hood to be more stable during the sliding process. ②. By connecting the pumping and sucking dual-purpose air pump through a four-way valve, the device circuit is simple, the components of the device are simplified, and compared with the traditional air extraction syringe, the integration degree of the sampling device is higher, reducing unnecessary labor and energy, and at the same time reducing the risk of insufficient airtightness of the device caused by loose connections. ③. The sampler can use one of a vacuum gas collection bag, a copper pipe, and a sampling glass bottle, with matching sizes, and can be easily installed and disassembled through pipe clamps, making the sampling device not limited to one type of sampler and enabling the collection of more types of gas samples. ④. The thin-film gauge can accurately record the air pressure in the sampler, which is convenient for subsequent direct detection after being noted. ⑤. When sampling with the high-temperature geothermal fluid sampling device of this embodiment, the accurate sampling time can be obtained through formula calculation, making the sampling process more efficient, and the collected geothermal gas can better meet the subsequent experimental requirements.

[0124] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-temperature geothermal fluid sampling device, characterized in that: It includes a sampling unit, a monitoring unit and a gas collection unit; The sampling unit comprises an air collecting hood (1), a movable rod (2), a waterproof breathable membrane (3) and a transmission pipeline (4); the air collecting hood (1) is arranged at a sampling point; the movable rod (2) is connected to the air collecting hood (1) to adjust the relative position of the air collecting hood and the sampling point; the air inlet end of the transmission pipeline (4) is adjustably connected to the air collecting hood (1); the waterproof breathable membrane (3) is arranged at the air inlet end of the transmission pipeline (4); The monitoring unit comprises a temperature sensor (5), a gas flow meter (6) and a film gauge (7), wherein the temperature sensor (5) is arranged in the gas collecting hood (1), the gas flow meter (6) is arranged in the transmission pipeline (4), and the film gauge (7) is arranged on the transmission pipeline (4); The gas collection unit comprises an exhaust gas collector (8), a sampler (9) and a power source (10); the exhaust gas collector (8) is arranged at the end of the transmission pipeline (4) for collecting exhaust gas; the sampler (9) is arranged on the transmission pipeline (4) or at the end of the transmission pipeline (4) for sampling the gas output by the transmission pipeline (4); and the power source (10) is arranged on the transmission pipeline (4).

2. The high-temperature geothermal fluid sampling device according to claim 1, characterized in that: The sampling unit further comprises an umbrella wing (11) which is detachably arranged on the gas collecting hood (1) and can expand the covering range of the gas collecting hood (1); the umbrella wing (11) comprises a single or multiple sleeved frustum-shaped body units.

3. The high-temperature geothermal fluid sampling device according to claim 1, characterized in that: The air inlet end of the transmission pipeline (4) is adjustably connected to the air collecting hood (1) by using a telescopic hose (12); The measuring range of the thin film gauge is 0.1-1000Torr, and the accuracy is 0.15% of the reading; the power source (10) is a dual-purpose air pump for whipping, and the output air pressure during operation is 90kPa-120kPa, and the flow rate is 5cm / s.

4. The high-temperature geothermal fluid sampling device according to any one of claims 1 to 3, characterized in that: The sampler (9) is a vacuum gas collection bag, which is connected to the pipe section in the transmission pipeline (4) located between the film gauge (7) and the tail gas collector (8).

5. The high-temperature geothermal fluid sampling device according to any one of claims 1 to 3, characterized in that: The sampler (9) comprises a fixed frame (9.1) and a copper tube (9.2), wherein the copper tube (9.2) is arranged on the fixed frame (9.1), and the air inlet end and the air outlet end of the copper tube (9.2) are both located outside the fixed frame (9.1), the air inlet end of the copper tube (9.2) is connected to a pipe section in the transmission pipeline (4) provided with a film gauge (7), and the air outlet end of the copper tube (9.2) is connected to a pipe section in the transmission pipeline (4) provided with an exhaust gas collector (8); valves and / or pipe clamps are used to fix the air inlet end of the copper tube (9.2) and the pipe section, and the air outlet end of the copper tube (9.2) and the pipe section.

6. The high-temperature geothermal fluid sampling device according to any one of claims 1 to 3, characterized in that: The sampler (9) comprises a sampling glass bottle (9.3) and a curved pipe (9.4); the sampling glass bottle (9.3) is filled with hot spring water and inverted in the tail gas collector (8); one end of the curved pipe (9.4) extends into the sampling glass bottle (9.3), and the other end is connected to or inserted into the end of the transmission pipe (4).

7. A high-temperature geothermal fluid sampling method, characterized in that: Sampling using the high-temperature geothermal fluid sampling device as described in any one of claims 1 to 6 comprises the following steps: Step 1: measuring the ambient temperature through the temperature sensor (5) on the gas collecting hood (1); selecting a gas collecting hood (1) that matches the parachute wing (11) of a suitable size according to the escape range of bubbles in the water at the sampling point; operating the moving lever (2) to place the gas collecting hood (1) at the bubble escape position; Step 2: When the gas collecting hood (1) is stationary on the water surface, the readings of the gas flow meter (6) and the temperature sensor (5) are observed. When the gas flow meter (6) and the temperature sensor (5) begin to display readings, the power source (10) is turned on to extract the geothermal gas to be collected until all the air in the high-temperature geothermal fluid sampling device is exhausted; Step 3: Select the corresponding sampler (9) for sampling as required.

8. The high-temperature geothermal fluid sampling method according to claim 7, characterized in that: The sampling time Time in step 3 is determined by the following formula: Where: v is the flow rate of geothermal gas; A is the cross-sectional area of ​​the transmission pipeline; P is the pressure of the gas at the flow-carrying section; T is the absolute temperature of 273.15K; T0 is the initial temperature of geothermal gas; ω is the relationship between cooling temperature and gas flow; V0 is the volume of the sampler.

9. The high-temperature geothermal fluid sampling method according to claim 8, characterized in that: The sampling time Time is determined by the following steps: Step a1, collecting a data set of gas temperature cooling over time during field geothermal gas sampling; Step a2, analyzing and processing the data set collected in step a1 to obtain the value of the constant k of each group of data, and determining the value of the constant k by calculating the mean and variance; Step a3: Divide the cooling process of the geothermal gas from the gas collecting hood to the sampler into N sections according to time, and based on the value of the constant k determined in step a2, introduce the Newton cooling formula to calculate the temperature T of the geothermal gas in the i-th time period during the cooling process. i , i is a natural number greater than or equal to 1 and less than N; Step a4: based on the temperature T of the i-th time period in the cooling process calculated in step a3 i , combined with the pipeline gas flow formula to obtain formula 1, through which the gas flow Q output by geothermal gas during the i-th period of time during the cooling process is calculated 冷却 ; Step a5: based on the cooling temperature T obtained in step a3 i and the gas flow Q obtained in step a4 冷却 , the relationship between cooling temperature and air flow rate ω is fitted; Step a6, based on the relationship ω fitted in step a5 and combined with the volume of the sampler, formula 2 is obtained, and the time required for the sampling process is calculated by formula 2; Formula 1: Formula 2: Where: Q 冷却 is the gas flow rate of geothermal gas output during the i-th period of time during the cooling process; T i-1 is the temperature corresponding to the i-1th stage in the cooling process; T m is the medium temperature, i.e. the atmospheric temperature; Tf is the cooling time.

10. The high-temperature geothermal fluid sampling method according to claim 7, characterized in that: Before sampling in step 3, it is necessary to determine whether the interior of the high-temperature geothermal fluid sampling device is emptied. The determination method is as follows: Step b1, using formula 1 to calculate the gas flow rate of geothermal gas output during the i-th period of time during the cooling process: Step b2: Calculate the total gas flow rate of geothermal gas during the entire cooling process using the following formula: Step b3: Make a judgment. If Q 总气流量 Greater than or equal to the total volume V of the high-temperature geothermal fluid sampling device a , then directly enter the subsequent sampling stage; if Q 总气流量 Smaller than the total volume V of the high-temperature geothermal fluid sampling device a , then the emptying time δT is extended, and δT is calculated using the following formula: Where: T Tf The temperature of geothermal gas after cooling.

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