A method and system for controlling the measurement environment of a Raman spectrometer

Abstract

The present invention provides a method and system for controlling the measurement environment of a Raman spectrometer, wherein the system includes a Raman spectrometer temperature control system, a sample purification and flow and pressure control system; the Raman spectrometer temperature control system includes a Raman spectrometer sample gas micro heater, a heat conductor temperature measuring meter, a gas temperature measuring tee, a gas temperature measuring meter, a Raman spectrometer optical path cell body, an optical path cell body temperature measuring meter, a temperature setting instrument, a PID operation program device, a regulator, a heater temperature controller, and an optical path cell temperature controller. The scheme of the present invention can solve the problem that the Raman spectrometer cannot adapt to the harsh and changeable logging field environment and the measurement value is inaccurate.

Description

Technical Field

[0001] The present invention belongs to the field of logging gas component detection, and in particular relates to a method and system for controlling the temperature, pressure and flow rate of high-speed flowing gas, thereby realizing the unification of the measurement environment of a Raman spectrometer under various logging field conditions. Background Art

[0002] Gas logging is the core technology of logging and is the most direct and effective means of discovering oil and gas layers. Its detection technologies mainly include hydrogen flame chromatography, thermal conductivity chromatography and infrared spectroscopy. Due to its shortcomings such as long detection cycle, few detection indicators, and recalibration and correction required when changing well positions, it has become increasingly difficult to adapt to the requirements of complex oil and gas reservoir exploration at this stage. Raman spectroscopy technology has become one of the most preferred technologies for conventional gas detection due to its many advantages such as simplicity, speed, high accuracy, no need for calibration and correction, and simultaneous detection of hydrocarbon and non-hydrocarbon gases. However, the Raman spectroscopy technology currently used for logging is not yet fully mature, and there are still difficulties in adapting to complex and changeable field environments.

[0003] The logging operation cycle is long, ranging from half a month to several years, with a large seasonal span, and the construction site environment is harsh, including various environments such as plains, deserts, mountains, and oceans in different regions. When the Raman spectrometer performs gas detection at the logging site, the measurement results will be affected by atmospheric pressure and temperature; on the other hand, the various impurities contained in the logging gas also pose a risk of contaminating the internal gas path and key parts of the spectrometer. In order to adapt to the complex and changeable harsh environment of the logging site, it is necessary to establish an environmental control system in the Raman spectrometer. During logging, the logging gas flows at high speed and its composition changes in real time. Its thermal conductivity and heat capacity are much lower than those of metals. It is very difficult to heat it up quickly and constantly in a limited space and at an extremely high sample flow rate. Combined with the procedures of flowing gas pressure control and purification treatment, the realization of the entire system is difficult.

[0004] In summary, to realize the application of Raman spectrometer in the field of on-site logging and gas measurement, the problem of the influence of the measurement environment on the detection results must be solved. Summary of the invention

[0005] The purpose of the present invention is to solve the defects of the above-mentioned prior art and provide a method and system for controlling the measurement environment of a Raman instrument so that the sample gas temperature, pressure and flow rate can be kept constant, and a sample pretreatment function is provided to realize the gas measurement application of the Raman spectrometer at the logging site.

[0006] The present invention adopts the following technical solution:

[0007] A Raman spectrometer sample gas micro heater comprises an inlet end cover, a heat conductor, an inlet end sealing gasket, a gas diffusion and rotation guide, a heat exchanger, a housing, an outlet end sealing gasket, a gas collecting block and an outlet end cover.

[0008] The middle part of the air inlet cover is an operation window I, and the air inlet cover is connected to the air inlet end connecting external thread of the shell through the connecting internal thread I. The thermal conductor is installed in the cavity formed by the air inlet cover and the shell, and the thermal conductor is formed by one-time processing of a copper rod.

[0009] The heat conductor is provided with an air inlet hole, which is connected with the air inlet threaded hole, and the gas enters the interior from the two air inlet holes; the air inlet end sealing gasket is installed in the shell, the gas diffuser and rotating guide is sleeved on the upper part of the heat conductor, the gas diffuser and rotating guide is provided with a plurality of gas rotating guide holes evenly distributed in the circumferential direction, the back of the gas diffuser and rotating guide is provided with an annular gas diffusion groove, and the upper part of the gas diffuser and rotating guide is a heat exchanger sleeved on the heat conductor.

[0010] The middle part of the outlet cover is the operation window II, and the outlet cover is connected to the outlet end connecting external thread of the shell through the connecting internal thread II. The gas collection block is installed in the cavity formed by the outlet cover and the shell, the top of the gas collection block has an outlet hole, the outlet end sealing gasket is installed in the shell, and the annular heat conducting sheet is installed at the bottom of the gas collection block. The annular heat conducting sheet is also installed on the heat conductor; the lower side of the annular heat conducting sheet is the heat exchanger.

[0011] Furthermore, the position of the gas diffusion and rotation guide hole is, with the center point o of the plane on the gas diffusion and rotation guide as the coordinate origin, x as the horizontal axis of the plane, y as the vertical axis of the plane, and z as the central axis; the center point of the ellipse formed by the intersection of the gas rotation guide hole and the upper plane is p; on the plane, a horizontal axis x' is made through point p, x'∥x, a vertical axis y' is made through point p, y' coincides with y; a plane perpendicular z' is made through point p, z'∥z; ι is the central axis of the gas rotation guide hole, then ι⊥y and ι and z' include an angle of 45°, that is, ι includes an angle of 90° with the radial direction and an angle of 45° with the axial direction.

[0012] Furthermore, the depth of the annular gas diffusion groove is 5 mm, and there are 24 gas rotation guide holes that are evenly distributed, with a hole diameter of 1 mm and an axial thickness of 5 mm.

[0013] Furthermore, the heat exchanger is formed by stacking 600 layers of 0.1mm thick annular copper mesh, which is woven into a mesh shape by multiple mutually perpendicular copper wires and then processed into a ring shape, and the angle between the copper wires of adjacent layers of copper mesh is 45°.

[0014] Furthermore, the center point of the plane on each layer of copper mesh of the heat exchanger is taken as the coordinate origin, x is the horizontal axis of the plane, y is the vertical axis of the plane, and z is the central axis of the annular copper mesh; during assembly, the central axes z of each layer of copper mesh coincide, the horizontal axes x of each layer of copper mesh are parallel to each other, and the vertical axes y are parallel to each other; the copper wire extension line a∥x and a⊥y of the first layer of copper mesh, the copper wire extension line b of the second layer is at an angle of 45° to x and y, the copper wire extension line c∥x and c⊥y of the third layer, and the copper wire extension line d of the fourth layer is at an angle of 45° to x and y, and they are arranged and stacked in this order, that is, the copper wire angles of adjacent layers of copper mesh are 45°. Furthermore, the total thickness of the heat exchanger is 60 mm, and the 100-mesh copper mesh has the best heat exchange effect, and the pressure loss is within an acceptable range.

[0015] A 3mm axial gap is left between the inner end surface of the gas collecting block and the end surface of the heat conductor, so that the gas flowing out of the annular heat conducting sheet can enter the gas outlet of the gas collecting block through the gap.

[0016] A further technical solution is that the Raman spectrometer sample gas micro heater is vertically installed in the Raman spectrometer chassis, with the air inlet end facing downward and the air outlet end facing upward.

[0017] A control system for a Raman spectrometer measurement environment, including a Raman spectrometer temperature control system, a sample purification, and a flow and pressure control system;

[0018] The Raman instrument temperature control system comprises a Raman spectrometer sample gas micro heater, a heat conductor temperature measuring meter, a gas temperature measuring tee, a gas temperature measuring meter, a Raman instrument optical path cell body, an optical path cell body temperature measuring meter, a temperature setting instrument, a PID operation program device, a regulator, a heater temperature controller, and an optical path cell temperature controller;

[0019] The sample purification and flow and pressure control system includes a sample gas extraction pump, a sample gas drying, a filter, a sample gas pressure regulating valve, a sample gas flow valve, a sample gas venting flow valve, a sample gas venting flow meter, and a Raman instrument optical path cell; a Raman instrument optical path cell relative pressure sensor, an atmospheric pressure sensor, a Raman instrument optical path cell relative pressure back pressure needle valve, and a Raman instrument sample gas flow meter;

[0020] The sample gas extraction pump is sequentially connected to the sample gas drying, filter, sample gas pressure regulating valve, sample gas flow valve, Raman spectrometer sample gas micro heater, gas temperature measurement tee, Raman instrument optical path cell, Raman instrument optical path cell relative pressure back pressure needle valve, and Raman instrument sample gas flow meter.

[0021] The heat conductor temperature measuring meter is connected to the heat conductor in the Raman spectrometer sample gas micro heater, the gas temperature measuring meter is connected to the gas temperature measuring tee, and the optical path cell body temperature measuring meters are respectively connected to the Raman instrument optical path cell body.

[0022] The optical path cell temperature controller is connected to the temperature setting instrument, and the optical path cell temperature controller is connected to the heating rod, and the heating rod is placed in the optical path cell body; the PID operation program device is respectively connected to the thermal conductor temperature measuring meter, the gas temperature measuring meter, and the temperature setting instrument, and is connected to the regulator, and the regulator is connected to the heater temperature controller;

[0023] The Raman instrument optical path cell relative pressure sensor is installed on the pipeline of the Raman instrument optical path cell gas outlet, and is no more than 50 mm away from the Raman instrument optical path cell gas outlet, so that the Raman instrument optical path cell relative pressure sensor can truly collect the relative pressure data in the Raman instrument optical path cell body;

[0024] The sample gas flow valve is placed at the rear end of the sample gas pressure-stabilizing valve, and is used to roughly adjust the flow through the Raman instrument optical path cell, and is detected and displayed by the Raman instrument sample gas flow meter (placed at the rear end of the optical path cell relative pressure back pressure needle valve 380); the atmospheric pressure sensor is welded on the control circuit board to detect the atmospheric pressure P in real time; the Raman instrument optical path cell relative pressure back pressure needle valve is placed at the rear end of the Raman instrument optical path cell relative pressure sensor to accurately adjust the relative pressure and flow of the sample gas in the optical path cell;

[0025] The sample gas vent flow valve is placed at the rear end of the sample gas drying and filter. The remaining sample gas discharged from the sample gas drying and filter is flow-regulated by the vent flow valve and detected and displayed by the sample gas vent flow meter.

[0026] A method for controlling a Raman spectrometer measurement environment comprises the following steps:

[0027] Step 1. Send the sample gas to the pretreatment unit for treatment, and a part of it is vented;

[0028] Specifically, it includes: starting the sample gas pump to suck the sample gas from A, and the pressurized sample gas is dried and filtered through the sample gas dryer and filter; adjusting the sample gas vent flow valve to close the sample gas vent flow valve; coordinating the knobs of the sample gas pressure regulating valve and the sample gas flow valve to preliminarily control the pressure and flow of the sample gas entering the Raman instrument main unit, ensuring that the absolute pressure of the sample gas entering the Raman instrument optical path cell body is slightly less than 110KPa and the flow rate is slightly greater than 500mL / min;

[0029] Step 2. Send the remaining part of the gas to the Raman spectrometer temperature control system for temperature treatment, including heating the gas through the Raman spectrometer sample gas micro heater;

[0030] Specifically, the sample gas after sample gas drying and filter purification enters the annular gas diffusion groove of the gas diffusion and rotation guide through the two air inlet holes on the thermal conductor, and enters the interior of the heater through 24 gas rotation guide holes under the action of pressure difference; the thermal conductor transfers heat to the heat exchanger, which is composed of multiple layers of 0.1mm thick annular copper mesh stacked together, and the copper wires of the upper and lower layers of copper mesh have an angle of 45°, resulting in local turbulence of the gas, and increasing the contact area with the copper wires of the copper mesh, thereby improving the heat exchange efficiency; under the action of pressure difference and gas rotation guide holes, the sample gas rotates and flows in the heat exchanger, and the gas and the heat exchanger undergo sufficient heat exchange; the temperature of the heated gas is directly related to the temperature of the heat exchanger, that is, the temperature of the thermal conductor, and the gas temperature is regulated by controlling the temperature of the thermal conductor.

[0031] Specifically, the temperature regulation of the thermal conductor includes:

[0032] The PID operation program device calculates the optimal temperature of the heat conductor according to the difference between the signal of the gas temperature meter and the temperature setting instrument, and presets the temperature of the heater temperature controller through the regulator. The heater temperature controller drives the heating rod to adjust the temperature of the heat conductor. After 2-3 cycles of correction by the PID operation program device, the gas temperature is accurately controlled to the set temperature. The temperature of the optical path cell body is accurately controlled to the set temperature by the optical path cell temperature controller to ensure that the temperature of the gas flowing into the optical path cell does not change.

[0033] Step 3. Send the gas treated in step 2 to the sample purification and flow and pressure control system for treatment;

[0034] Step 4: exhaust the gas in step 3.

[0035] A further technical solution is that the sample gas pressure adjusted by the pretreatment unit is slightly less than 110KPa and the flow rate is slightly greater than 500mL / min. The back pressure needle valve is fine-tuned clockwise, the pressure rises to 110KPa, and the flow rate drops to 500mL / min, and vice versa. The Raman instrument analysis results are significantly affected by the gas pressure in the optical path cell. When the pressure is high, the analysis results are biased to large, and when the pressure is low, the analysis results are biased to small.

[0036] A further technical solution is that the analysis result is not obviously related to the sample gas flow rate, so the pressure and flow control give priority to accurately control the pressure in the Raman instrument optical path cell to reach the set value, and the flow control is second. The sample gas is vented from B after passing through the sample gas vent flowmeter; in order to respond to the changes in gas composition and concentration at the gas source in a timely manner, it is necessary to increase and maintain the flow A entering the sample purification system, open and adjust the sample gas vent flow valve, so that the flow through the sample gas vent flowmeter meets the vent pressure suitable for the site, and the excess sample gas is vented along C.

[0037] Beneficial effects of the present invention:

[0038] Temperature control: The temperature control system consists of two subsystems, namely the Raman instrument temperature control system and the sample purification and flow and pressure control system.

[0039] Before the sample gas enters the optical path cell cavity, the sample gas is heated to a predetermined temperature; due to the small heat capacity of the gas, in order to prevent the sample gas from exchanging heat in the optical path cell cavity and causing the concentration to change, the optical path cell body is heated and insulated to keep it constant at a predetermined temperature, ensuring that the temperature and concentration of the sample gas in the cavity remain constant. The sample gas is heated by a Raman spectrometer sample gas micro heater, and a gas diffusion groove and a rotating guide hole are installed at the annular air inlet end to make the gas partially turbulent in the annular space and the heat exchanger, and the gas moves in a spiral rotation along the axis as a whole, ensuring that the heated gas is in full contact with the heat dissipation surface of the heat exchanger.

[0040] Raman instrument temperature control system: sensors are installed on the micro heater thermal conductor and in the heated gas output pipeline to detect the temperature. The PID operation program device responds to the difference between the detection result and the set temperature, and corrects the preset value of the temperature controller that controls the heater thermal conductor, so that the gas finally reaches the set temperature. The optical path cell body is heated and controlled by a temperature controller to maintain its temperature at the set temperature.

[0041] Sample purification and flow and pressure control system: The system consists of a vacuum pump, a pressure regulating valve, a flow valve, a venting flow valve, a back pressure needle valve, a float flowmeter, an atmospheric pressure sensor, an optical path cell relative pressure sensor and other components. The vacuum pump extracts gas and compresses it, controls the pressure and flow through the pressure regulating valve and the flow valve, controls the size of the gas exhaust channel cross section through the back pressure needle valve to accurately control the relative pressure and flow of the optical path cell, and the excess sample gas is vented through the venting needle valve. The atmospheric pressure and relative pressure are measured and collected in real time through the relative sensor, and the sum of the two is the absolute pressure of the gas in the optical path cell of the Raman spectrometer. By adjusting the back pressure needle valve, the relative pressure of the gas in the cell changes to overcome the difference in atmospheric pressure, and finally ensure that the absolute pressure of the gas in the cell is wirelessly close to the established target value. The established target value of the absolute pressure of the gas in the optical path cell is 110Kpa.

[0042] Through the above system, the temperature and absolute pressure of the sample gas can be kept constant during the detection process of the Raman spectrometer, overcoming the analysis differences caused by different ambient temperatures, different altitudes, and different atmospheric pressures. It also has drying and evolution functions, creating a stable detection environment for the Raman spectrometer, making real-time detection of the Raman spectrometer at the logging site possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1is a schematic structural diagram of a micro heater provided in Example 1 of the present invention;

[0044] FIG. 2( a ) and FIG. 2( b ) are schematic diagrams of the heat conductor structure of the micro-heater provided in Example 1 of the present invention;

[0045] FIG. 3( a ) and FIG. 3( b ) are schematic diagrams of the gas diffuser and guide structure provided in Example 1 of the present invention;

[0046] Figure 4 Schematic diagram of the opening angles of the gas diffusion and guide holes of the guide provided in Example 1 of the present invention;

[0047] Figure 5 is a schematic diagram of the heat exchanger structure of the micro heater provided in Example 1 of the present invention;

[0048] Figure 6 is a temperature control structure diagram provided in Example 1 of the present invention;

[0049] Figure 7 It is a structural diagram of the sample gas purification and flow and pressure control system provided in Example 1 of the present invention;

[0050] Figure 8 A schematic diagram of the structure and flow of sample gas purification, flow rate, pressure control system and temperature control provided in an embodiment of the present invention;

[0051] Fig. 9 Example 1 of the present invention is a pressure-concentration curve diagram of 1.00% methane analyzed by Raman instrument under different pressure environments;

[0052] Fig.10 The embodiment 1 of the present invention is a pressure-concentration curve diagram of 10.00% methane analyzed by Raman instrument under different pressure environments;

[0053] Fig.11 The embodiment 1 of the present invention is a pressure-concentration curve diagram of 80.00% methane analyzed by Raman instrument under different pressure environments;

[0054] Fig.12 The present invention is a pressure-concentration curve diagram of 399.8 ppm isopentane analyzed by Raman spectroscopy under different pressure environments in Example 1;

[0055] Fig.13 The present invention is a pressure-concentration curve diagram of 2034 ppm isopentane analyzed by Raman spectroscopy under different pressure environments in Example 1;

[0056] Fig.14 The present invention is a pressure-concentration curve diagram of 4.98% isopentane analyzed by Raman analysis under different pressure environments in Example 1.

[0057] In the figure:

[0058] 100-Raman spectrometer sample gas micro heater;

[0059] 110-inlet cover, 111-operation window Ⅰ, 112-connection internal thread Ⅰ, 120-heat conductor, 121-inlet hole, 122-inlet thread hole, 123-heating rod mounting hole, 124-temperature probe mounting hole, 130-inlet end sealing gasket, 140-gas diffusion and rotation guide, 141-gas rotation guide hole, 142-annular gas diffusion groove, 150-heat exchanger, 151-annular heat conducting plate, 160-housing, 161-inlet end connection external thread, 162-outlet end connection external thread, 170-outlet end sealing gasket, 180-gas collection block, 181-outlet hole, 190-outlet cover, 191-operation window Ⅱ, 192-connection internal thread Ⅱ;

[0060] 200-Raman instrument temperature control system;

[0061] 100-Raman spectrometer sample gas micro heater, 211-thermal conductor temperature measuring meter, 220-gas temperature measuring tee, 221-gas temperature measuring meter, 230-Raman instrument optical path cell body, 231-optical path cell body temperature measuring meter, 240-temperature setting instrument, 250-PID operation program device, 260-regulator, 270-heater temperature controller, 280-optical path cell temperature controller;

[0062] 300-Raman instrument sample gas purification and flow and pressure control system;

[0063] 310-sample gas suction pump, 320-sample gas drying, filter, 330-sample gas pressure regulating valve, 340-sample gas flow valve, 341-sample gas vent flow valve, 350-sample gas vent flow meter, 360-Raman instrument optical path cell, 370-Raman instrument optical path cell relative pressure sensor, 371-atmospheric pressure sensor, 380-Raman instrument optical path cell relative pressure back pressure needle valve, 390-Raman instrument sample gas flow meter;

[0064] M-preprocessing unit, N-Raman instrument main chassis. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] like Figure 1As shown, the Raman spectrometer sample gas micro heater 100 includes an air inlet end cover 110, a heat conductor 120, an air inlet end seal 130, a gas diffusion and rotation guide 140, a heat exchanger 150, a housing 160, an air outlet end seal 170, a gas collection block 180, and an air outlet end cover 190. The Raman spectrometer sample gas micro heater 100 is vertically installed in the Raman instrument chassis, with the air inlet end facing downward and the air outlet end facing upward.

[0067] The middle part of the air inlet cover 110 is an operation window Ⅰ111, and the air inlet cover 110 is connected to the air inlet end connecting external thread 161 of the housing 160 through the connecting internal thread Ⅰ112. The heat conductor 120 is installed in the cavity formed by the air inlet cover 110 and the housing 160. The heat conductor 120 is formed by one-time processing of a copper rod to ensure the heat transfer efficiency, as shown in Figure 2 (a) and Figure 2 (b).

[0068] The heat conductor 120 has an air inlet hole 121, and the air inlet hole 121 and the air inlet threaded hole 122 are connected, and the gas enters the interior from the two air inlet holes 121; the air inlet end sealing gasket 130 is installed in the shell 160 for sealing the lower part, and the gas diffuser and rotary guide 140 is sleeved on the upper part of the heat conductor 120. The gas diffuser and rotary guide 140 has a plurality of gas rotary guide holes 141 uniformly distributed in the circumferential direction, and the back of the gas diffuser and rotary guide 140 has an annular gas diffusion groove 142. The upper part of the gas diffuser and rotary guide 140 is a heat exchanger 150 sleeved on the heat conductor 120. The total thickness of the gas diffuser and rotary guide 140 is 10 mm, as shown in Figures 3(a) and 3(b).

[0069] The center point o of the plane on the gas diffusion and rotation guide 140 is taken as the coordinate origin, x is the horizontal axis of the plane, y is the vertical axis of the plane, and z is the central axis; the center point of the ellipse formed by the intersection of the gas rotation guide hole 141 and the upper plane is p; on the plane, a horizontal axis x' is made through point p, x'||x, a vertical axis y' (radial) is made through point p, y' coincides with y; a plane perpendicular z' (axial) is made through point p, z'||z; ι is the central axis of the gas rotation guide hole, then ι⊥y and ι and z' are at an angle of 45°, that is, ι is at an angle of 90° with the radial direction and 45° with the axial direction, such as Figure 4 shown.

[0070] The depth of the annular gas diffusion groove 142 is 5 mm, and there are 24 gas rotation guide holes 141 in total and they are evenly distributed, with a hole diameter of 1 mm and an axial thickness of 5 mm.

[0071] like Figure 5 As shown, the heat exchanger 150 is formed by stacking 600 layers of 0.1 mm thick annular copper mesh, which is woven into a mesh shape by multiple mutually perpendicular copper wires and then processed into an annular shape. The angle between the copper wires of adjacent layers of copper mesh is 45°.

[0072] The center point of the plane on each layer of copper mesh of the heat exchanger 150 is taken as the coordinate origin, x is the horizontal axis of the plane, y is the vertical axis of the plane, and z is the central axis of the annular copper mesh; when assembled, the central axes z of each layer of copper mesh coincide, the horizontal axes x of each layer of copper mesh are parallel to each other, and the vertical axes y are parallel to each other; the extension line a∥x and a⊥y of the copper wire of the first layer of copper mesh, the extension line b of the copper wire of the second layer is 45° with x and y, the extension line c∥x and c⊥y of the copper wire of the third layer, and the extension line d of the copper wire of the fourth layer is 45° with x and y, and the copper wires of the adjacent layers of copper mesh are arranged and stacked in this order, that is, the angle between the copper wires of the adjacent layers of copper mesh is 45°, such as Figure 5 The total thickness of the heat exchanger is 60 mm, and the 100-mesh copper mesh has the best heat exchange effect, while the pressure loss is within an acceptable range.

[0073] The middle of the outlet cover 190 is an operation window II 191, and the outlet cover 190 is connected to the outlet end connecting external thread 162 of the housing 160 through the connecting internal thread II 192. The gas collection block 180 is installed in the cavity formed by the outlet cover 190 and the housing 160, and the top of the gas collection block 180 has an outlet hole 181. The outlet end sealing gasket 170 is installed in the housing 160 for upper sealing, and the annular heat conducting sheet 151 is installed at the bottom of the gas collection block 180.

[0074] The annular heat conducting sheet 151 is also installed on the heat conductor 120 ; the heat exchanger 150 is located at the lower side of the annular heat conducting sheet 120 .

[0075] The dimensions of the thermal conductor 120, the housing 160, and the gas collecting block 180 should be appropriate to ensure that there is a 3 mm axial gap between the inner end face of the gas collecting block 180 and the end face of the thermal conductor 120, so that the gas flowing out of the annular heat conductive plate 151 can enter the gas outlet 181 of the gas collecting block 180 through the gap.

[0076] Preferably, the heat conductor 120 includes a copper rod, a copper tube and a copper mesh. A heating rod is placed in the copper rod. The copper rod is covered with a copper tube as an outer shell, so that an annular space of about 5 mm is formed between the outer wall of the copper rod and the inner wall of the copper tube. The inside of the annular space is filled with a heat exchanger 150 composed of stacked 100-mesh copper mesh.

[0077] After the sample gas enters the interior from the two air inlet holes 121, it diffuses through the annular gas diffusion groove 142, and is ejected into the annular space from the gas rotation guide hole 141 driven by the pressure difference; under the joint action of the gas diffusion and rotation guide 140 and the inner wall of the outer shell 160, the gas spirally rotates and rises along the axis in the annular space, further increasing the contact surface area between the gas and the heat exchanger 150, thereby improving the heat exchange efficiency.

[0078] like Figure 6As shown, the Raman instrument temperature control system 200 includes a Raman spectrometer sample gas micro heater 100, a thermal conductor temperature measuring meter 211, a gas temperature measuring tee 220, a gas temperature measuring meter 221, a Raman instrument optical path cell body 230, an optical path cell body temperature measuring meter 231, a temperature setting instrument 240, a PID operation program device 250, a regulator 260, a heater temperature controller 270, and an optical path cell temperature controller 280.

[0079] After being dried, filtered, voltage stabilized, and constant flowed by the sample purification system, the Raman instrument sample gas enters the Raman instrument temperature control system 200 along A, flows through the Raman instrument sample gas micro heater 100, the gas temperature measurement tee 220, and the Raman instrument optical path cell body 230, and then flows out of the Raman instrument temperature control system 200 along C.

[0080] Because the gas heat capacity is small and the gas temperature is higher than the ambient temperature in the chassis, the distance between the Raman instrument sample gas micro heater 100, the gas temperature measurement tee 220, and the Raman instrument optical path cell body 230 is as small as possible, and thermal insulation measures are taken for the gas pipeline. The thermal conductor temperature meter 211, the gas temperature meter 221, and the optical path cell body temperature meter 231 respectively measure the temperature of the thermal conductor 120, the gas in the gas temperature measurement tee 220, and the optical path cell body 230. The preset temperature of the optical path cell temperature controller 280 is set by the temperature setting instrument 240; the optical path cell temperature controller 280 automatically calculates and drives the heating rod to heat and keep the optical path cell body 230 warm, so as to ensure that the measured object - gas flowing through the optical path cell cavity does not undergo heat exchange and heat transfer; the PID calculation program device 250 calculates the optimal temperature data of the thermal conductor 120 according to the signals of the thermal conductor temperature meter 211, the gas temperature meter 221, and the temperature setting instrument 240, and adjusts the preset temperature of the heater temperature controller 270 through the regulator 260; the heater temperature controller 270 automatically calculates and drives the heating rod to heat the thermal conductor 120; the preset temperature of the temperature setting instrument 240 is 50°C, and the setting operation is performed through the software interface.

[0081] like Figure 7As shown, the gas flows from A into the sample gas pretreatment unit, then into the Raman instrument mainframe chassis, flows through the optical path cell and is vented from C, and the remaining sample gas is vented from B. The Raman instrument sample gas purification and flow and pressure control system 300 includes a sample gas pump 310, a sample gas drying and filter 320, a sample gas pressure regulating valve 330, a sample gas flow valve 340, a sample gas venting flow valve 341, a sample gas venting flow meter 350, and a Raman instrument optical path cell 360; a Raman instrument optical path cell relative pressure sensor 370, an atmospheric pressure sensor 371, a Raman instrument optical path cell relative pressure back pressure needle valve 380, and a Raman instrument sample gas flow meter 390.

[0082] The sample gas pump 310 is powered by a single-phase 220VAC, has a no-load displacement of 1500-2000mL / min, and an output maximum pressure of 0.15Mpa; the sample gas drying and filter 320 is placed at the front end of the Raman instrument optical path pool 360; the Raman instrument optical path pool relative pressure sensor 370 and the atmospheric pressure sensor 371 are the main detection components of the pressure system, and the sum of the detection data is the absolute pressure of the sample gas in the optical path pool, and the absolute pressure established parameter is 110Kpa; the sample gas pressure regulating valve 330 roughly adjusts the relative pressure of the sample gas in the Raman instrument optical path pool 360, is set between the sample gas drying and filter 320 and the sample gas flow valve 340, and is controlled by the relative pressure sensor The sample gas flow valve 340 roughly adjusts the flow through the Raman instrument optical path pool 360, is arranged after the sample gas pressure-stabilizing valve 330, and is detected and displayed by the Raman instrument sample gas flow meter 390, and the set flow parameter is 500mL / min; the atmospheric pressure sensor 371 detects the atmospheric pressure P in real time; the Raman instrument optical path pool relative pressure back pressure needle valve 380 accurately adjusts the relative pressure and flow of the sample gas in the optical path pool, and is arranged after the Raman instrument optical path pool 360; the sample gas vent flow valve 341 adjusts the excess sample gas flow, is arranged after the sample gas drying and filter 320, and is detected and displayed by the sample gas vent flow meter 350.

[0083] See Figure 8 As shown, in the whole system, the sample gas suction pump 310 to the sample gas venting flowmeter 350 are placed as a sample purification system, which is placed in the pretreatment unit M, and the Raman instrument optical path cell 360 to the Raman instrument sample gas flowmeter 390 are the sample flow and pressure control system, and are placed in the Raman instrument host chassis N.

[0084] The gas flows into the sample gas sample purification system from A, then enters the Raman instrument mainframe chassis, flows through the optical path cell and is discharged from C, and the remaining sample gas is discharged from B. Specifically, after the gas enters the sample gas pump 310 from A, it passes through the sample gas drying, filter 320, sample gas pressure regulating valve 330, sample gas flow valve 340, Raman spectrometer sample gas micro heater 100, gas temperature measurement tee 220, Raman instrument optical path cell 360, Raman instrument optical path cell relative pressure back pressure needle valve 380, Raman instrument sample gas flow meter 390 and then is discharged from C.

[0085] The heat conductor temperature measuring meter 211, the gas temperature measuring meter 221, and the optical path cell body temperature measuring meter 231 respectively measure the temperature of the heat conductor 120 in the Raman spectrometer sample gas micro heater 100, the gas in the gas temperature measuring tee 220, and the optical path cell body 230. The preset temperature of the optical path cell temperature controller 280 is set by the temperature setting instrument 240; the optical path cell temperature controller 280 automatically calculates and drives the heating rod to heat and keep the optical path cell body 230; the PID calculation program device 250 collects the signals of the heat conductor temperature measuring meter 211, the gas temperature measuring meter 221, and the temperature setting instrument 240, and adjusts the preset temperature of the heater temperature controller 270 through the regulator 260; the heater temperature controller 270 automatically calculates and drives the heating rod to heat the heat conductor 120.

[0086] The sample gas pressure-stabilizing valve 330 roughly adjusts the relative pressure of the sample gas in the Raman instrument optical path cell 360, and is detected by the relative pressure sensor 370; the sample gas flow valve 340 roughly adjusts the flow through the Raman instrument optical path cell 360, and is detected and displayed by the Raman instrument sample gas flow meter 390; the atmospheric pressure sensor 371 detects the atmospheric pressure P in real time; the Raman instrument optical path cell relative pressure back pressure needle valve 380 accurately adjusts the relative pressure and flow of the sample gas in the optical path cell.

[0087] The remaining sample gas discharged from the sample gas drying and filter 320 is adjusted by the sample gas venting flow valve 341 and detected and displayed by the sample gas venting flow meter 350 .

[0088] A method for controlling a Raman spectrometer measurement environment comprises the following steps:

[0089] Step 1. Send the sample gas to the pretreatment unit for treatment, and a part of it is vented;

[0090] Specifically, it includes: starting the sample gas pump to suck the sample gas from A, and the pressurized sample gas is dried and filtered through the sample gas dryer and filter; adjusting the sample gas vent flow valve to close the sample gas vent flow valve; coordinating the knobs of the sample gas pressure regulating valve and the sample gas flow valve to preliminarily control the pressure and flow of the sample gas entering the Raman instrument main unit, ensuring that the absolute pressure of the sample gas entering the Raman instrument optical path cell body is slightly less than 110KPa and the flow rate is slightly greater than 500mL / min;

[0091] Step 2. Send the remaining part of the gas to the Raman spectrometer temperature control system for temperature treatment, including heating the gas through the Raman spectrometer sample gas micro heater;

[0092] Specifically, the sample gas after sample gas drying and filter purification enters the annular gas diffusion groove of the gas diffusion and rotation guide through the two air inlet holes on the thermal conductor, and enters the interior of the heater through 24 gas rotation guide holes under the action of pressure difference; the thermal conductor transfers heat to the heat exchanger, which is composed of multiple layers of 0.1mm thick annular copper mesh stacked together, and the copper wires of the upper and lower layers of copper mesh have an angle of 45°, resulting in local turbulence of the gas, and increasing the contact area with the copper wires of the copper mesh, thereby improving the heat exchange efficiency; under the action of pressure difference and gas rotation guide holes, the sample gas rotates and flows in the heat exchanger, and the gas and the heat exchanger undergo sufficient heat exchange; the temperature of the heated gas is directly related to the temperature of the heat exchanger, that is, the temperature of the thermal conductor, and the gas temperature is regulated by controlling the temperature of the thermal conductor.

[0093] Specifically, the temperature regulation of the thermal conductor includes:

[0094] The PID operation program device calculates the optimal temperature of the heat conductor according to the difference between the signal of the gas temperature meter and the temperature setting instrument, and presets the temperature of the heater temperature controller through the regulator. The heater temperature controller drives the heating rod to adjust the temperature of the heat conductor. After 2-3 cycles of correction by the PID operation program device, the gas temperature is accurately controlled to the set temperature. The temperature of the optical path cell body is accurately controlled to the set temperature by the optical path cell temperature controller to ensure that the temperature of the gas flowing into the optical path cell does not change.

[0095] Step 3. Send the gas treated in step 2 to the sample purification and flow and pressure control system for treatment;

[0096] Step 4: exhaust the gas in step 3.

[0097] A further technical solution is that the sample gas pressure adjusted by the pretreatment unit is slightly less than 110KPa and the flow rate is slightly greater than 500mL / min. The back pressure needle valve is fine-tuned clockwise, the pressure rises to 110KPa, and the flow rate drops to 500mL / min, and vice versa. The Raman instrument analysis results are significantly affected by the gas pressure in the optical path cell. When the pressure is high, the analysis results are biased to large, and when the pressure is low, the analysis results are biased to small.

[0098] A further technical solution is that the analysis result is not obviously related to the sample gas flow rate, so the pressure and flow control give priority to accurately control the pressure in the Raman instrument optical path cell to reach the set value, and the flow control is second. The sample gas is vented from B after passing through the sample gas vent flowmeter; in order to respond to the changes in gas composition and concentration at the gas source in a timely manner, it is necessary to increase and maintain the flow A entering the sample purification system, open and adjust the sample gas vent flow valve, so that the flow through the sample gas vent flowmeter meets the vent pressure suitable for the site, and the excess sample gas is vented along C.

[0099] Example

[0100] At different altitudes / different atmospheric pressure environments, different relative pressures, and different absolute pressures, the temperature of the optical path cell is set at 50°C, and the temperature of the gas entering the optical path cell is set at 50°C. After preheating for about 60 minutes, the temperature of the optical path cell and the temperature of the gas entering the optical path cell body 230 are both constant at 50±0.5°C. Six different types and concentrations of standard gases are pumped into the Raman instrument for analysis.

[0101] 1. Experimental location:

[0102] ①Feiniuba Village, Yongxing Town, Mianyang: Altitude 476m, atmospheric pressure 95.941Kpa; ②Suburb of Kangding: Altitude 2292m, atmospheric pressure 77.170-77.181Kpa; ③Zhonggu Village, Yala Mountain, Kangding: Altitude 2980m, atmospheric pressure 70.74Kpa.

[0103] 2. Pressure parameters: ① The above three experimental locations were analyzed under normal pressure; ② The above three experimental locations were analyzed under a constant absolute pressure of 110±0.1Kpa.

[0104] 3. Sample gas type and concentration: ①CH 4 :1% (standard sample); ②CH 4 :10%(standard sample); ③CH 4 :80% (split its configuration); ④iC 5 :399.8ppm(standard sample);⑤iC 5 :2034ppm(standard sample);⑥iC 5 :4.98%(standard sample).

[0105] The experimental data are shown in Tables 1 to 6 below:

[0106] Table 1 Comparison of Raman Analyzer Analysis Data in Different Pressure Environments

[0107]

[0108] Table 2 Comparison of Raman Analyzer Analysis Data in Different Pressure Environments

[0109]

[0110] Table 3 Comparison of Raman Analyzer Analysis Data in Different Pressure Environments

[0111]

[0112] Table 4 Comparison of Raman analysis data in different pressure environments

[0113]

[0114] Table 5 Comparison of Raman Analyzer Analysis Data in Different Pressure Environments

[0115]

[0116] Table 6 Comparison of Raman Analyzer Analysis Data in Different Pressure Environments

[0117]

[0118] Generate graphs of the experimental data according to atmospheric pressure-concentration, relative pressure-concentration, and absolute pressure-concentration. Figure 9-14 .

[0119] from Figure 9-14 It can be seen that the Raman instrument analysis results have a poor linear relationship with atmospheric pressure and relative pressure, but have a good linear relationship with the sum of atmospheric pressure and relative pressure, that is, absolute pressure. This shows that absolute pressure is the key factor affecting the accuracy of the measurement results, so the absolute pressure needs to be kept constant during the measurement process.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Raman spectrometer sample gas micro heater, It is characterized in that It includes an air inlet end cover, a heat conductor, an air inlet end seal, a gas diffuser and a rotary guide, a heat exchanger, a housing, an air outlet end seal, a gas collecting block, and an air outlet end cover; The middle part of the air inlet cover is an operation window I, and the air inlet cover is connected to the air inlet end connecting external thread of the shell through the connecting internal thread I, and the thermal conductor is installed in the cavity formed by the air inlet cover and the shell, and the thermal conductor is formed by one-step processing of a copper rod; The heat conductor is provided with an air inlet hole and an air inlet threaded hole, the air inlet hole and the air inlet threaded hole are connected, and the gas enters the interior from the two air inlet holes; the air inlet end sealing gasket is installed in the shell, the gas diffuser and rotary guide is sleeved on the upper part of the heat conductor, the gas diffuser and rotary guide is provided with a plurality of gas rotary guide holes uniformly distributed in the circumferential direction, the back of the gas diffuser and rotary guide is provided with an annular gas diffusion groove, and the upper part of the gas diffuser and rotary guide is a heat exchanger sleeved on the heat conductor; The middle part of the outlet cover is an operation window II, and the outlet cover is connected to the outlet end connecting external thread of the shell through the connecting internal thread II. The gas collecting block is installed in the cavity formed by the outlet cover and the shell, and the top of the gas collecting block is provided with an outlet hole. The outlet end sealing gasket is installed in the shell, and the annular heat conducting sheet is installed at the lower part of the gas collecting block. The annular heat conducting sheet is also installed on the heat conductor, and the lower side of the annular heat conducting sheet is a heat exchanger; The position of the gas diffusion and rotation guide hole is, with the center point o of the plane on the gas diffusion and rotation guide as the coordinate origin, x as the horizontal axis of the plane, y as the vertical axis of the plane, and z as the central axis; the center point of the ellipse formed by the intersection of the gas rotation guide hole and the upper plane is p; on the plane, the horizontal axis x' is made through point p, x'∥x, the vertical axis y' is made through point p, y' coincides with y; the plane vertical line z' is made through point p, z'∥z; ι is the central axis of the gas rotation guide hole, then ι⊥y and ι and z' are at an angle of 45°, that is, ι is at an angle of 90° with the radial direction and 45° with the axial direction; The depth of the annular gas diffusion groove is 5 mm, and there are 24 gas rotation guide holes that are evenly distributed, with a hole diameter of 1 mm and an axial thickness of 5 mm.

2. The Raman spectrometer sample gas micro heater according to claim 1, It is characterized in that The heat exchanger is made of 600 layers of 0.1mm thick annular copper mesh. The annular copper mesh is woven into a mesh with multiple mutually perpendicular copper wires and then processed into a ring. The angle between the copper wires of adjacent layers of copper mesh is 45°.

3. The Raman spectrometer sample gas micro heater according to claim 2, It is characterized in that The structure of copper mesh installation is: take the center point of the plane on each layer of copper mesh of the heat exchanger as the coordinate origin, x is the horizontal axis of the plane, y is the vertical axis of the plane, and z is the central axis of the annular copper mesh; during assembly, the central axis z of each layer of copper mesh coincides, the horizontal axis x of each layer of copper mesh is parallel to each other, and the vertical axis y is parallel to each other; the copper wire extension line a∥x and a⊥y of the first layer of copper mesh, the copper wire extension line b of the second layer is at an angle of 45° with x and y, the copper wire extension line c∥x and c⊥y of the third layer, and the copper wire extension line d of the fourth layer is at an angle of 45° with x and y, and they are arranged and stacked in this order, that is, the copper wire angle of adjacent layers of copper mesh is 45°.

4. The Raman spectrometer sample gas micro heater according to claim 1, It is characterized in that A 3mm axial gap is left between the inner end surface of the gas collecting block and the end surface of the heat conductor, so that the gas flowing out of the annular heat conducting sheet can enter the gas outlet of the gas collecting block through the gap.

5. A control system for the measurement environment of a Raman spectrometer, It is characterized in that Including Raman instrument temperature control system, sample purification and flow and pressure control system; The Raman instrument temperature control system comprises a Raman spectrometer sample gas micro heater as claimed in claim 1, a heat conductor temperature measuring meter, a gas temperature measuring tee, a gas temperature measuring meter, a Raman instrument optical path cell body, an optical path cell body temperature measuring meter, a temperature setting instrument, a PID operation program device, a regulator, a heater temperature controller, and an optical path cell temperature controller; The sample purification and flow and pressure control system includes a sample gas extraction pump, a sample gas drying, a filter, a sample gas pressure regulating valve, a sample gas flow valve, a sample gas venting flow valve, a sample gas venting flow meter, and a Raman instrument optical path cell; a Raman instrument optical path cell relative pressure sensor, an atmospheric pressure sensor, a Raman instrument optical path cell relative pressure back pressure needle valve, and a Raman instrument sample gas flow meter; The sample gas extraction pump is connected in sequence to the sample gas drying, filter, sample gas pressure regulating valve, sample gas flow valve, Raman spectrometer sample gas micro heater, gas temperature measurement tee, Raman instrument optical path cell, Raman instrument optical path cell relative pressure back pressure needle valve, and Raman instrument sample gas flow meter; The heat conductor temperature measuring meter is connected to the heat conductor in the Raman spectrometer sample gas micro heater, the gas temperature measuring meter is connected to the gas temperature measuring tee, and the optical path cell body temperature measuring meters are respectively connected to the Raman spectrometer optical path cell body; The optical path cell temperature controller is connected to the temperature setting instrument, and the optical path cell temperature controller is connected to the heating rod, and the heating rod is placed in the optical path cell body of the Raman instrument; the PID operation program device is respectively connected to the thermal conductor temperature measuring meter, the gas temperature measuring meter, the temperature setting instrument, and is connected to the regulator, and the regulator is connected to the heater temperature controller; The Raman instrument optical path cell relative pressure sensor is installed on the pipeline of the Raman instrument optical path cell gas outlet, the sample gas flow valve is placed at the rear end of the sample gas pressure regulating valve, and is detected and displayed by the Raman instrument sample gas flow meter, and the Raman instrument sample gas flow meter is located at the rear end of the Raman instrument optical path cell relative pressure back pressure needle valve; the atmospheric pressure sensor is welded on the control circuit board to detect the atmospheric pressure P in real time, and the Raman instrument optical path cell relative pressure back pressure needle valve is placed at the rear end of the Raman instrument optical path cell relative pressure sensor; The sample gas vent flow valve is placed at the rear end of the sample gas drying and filter. The remaining sample gas discharged from the sample gas drying and filter is flow-regulated by the sample gas vent flow valve and detected and displayed by the sample gas vent flow meter.

6. A method for controlling the measurement environment of a Raman spectrometer, It is characterized in that The steps include: Step 1. Send the sample gas to the pretreatment unit for treatment, and a part of it is vented; Specifically, it includes: starting the sample gas pump to suck the sample gas from A, and the pressurized sample gas is dried and filtered through the sample gas dryer and filter; adjusting the sample gas vent flow valve to close the sample gas vent flow valve, and coordinating the knobs of the sample gas pressure regulating valve and the sample gas flow valve to preliminarily control the pressure and flow of the sample gas entering the Raman instrument main unit, ensuring that the absolute pressure of the sample gas entering the Raman instrument optical path cell body is less than 110KPa and the flow rate is greater than 500mL / min; Step 2. Sending the remaining part of the gas into the Raman spectrometer temperature control system for temperature treatment, which includes heating the gas by the Raman spectrometer sample gas micro heater as claimed in claim 1; Specifically, the sample gas after drying and filter purification enters the annular gas diffusion groove of the gas diffusion and rotation guide through the two air inlet holes on the heat conductor, and enters the heater through 24 gas rotation guide holes under the action of pressure difference; the heat conductor transfers heat to the heat exchanger, which is composed of multiple layers of 0.1mm thick annular copper mesh, and the copper wires of the upper and lower layers of copper mesh have an angle of 45°, so that the gas is locally turbulent, and the contact area with the copper wires of the copper mesh is increased, thereby improving the heat exchange efficiency; under the action of pressure difference and gas rotation guide holes, the sample gas rotates and flows in the heat exchanger, and the gas and the heat exchanger have sufficient heat exchange; the temperature of the heated gas is directly related to the temperature of the heat exchanger, that is, the temperature of the heat conductor, and the gas temperature is regulated by controlling the temperature of the heat conductor; Temperature regulation of thermal conductors includes: The PID operation program device calculates the optimal temperature of the heat conductor according to the difference between the signal of the gas temperature measuring meter and the temperature setting instrument, and presets the temperature of the heater temperature controller through the regulator. The heater temperature controller drives the heating rod to adjust the temperature of the heat conductor. After 2-3 cycles of correction by the PID operation program device, the gas temperature is accurately controlled to the set temperature; the temperature of the optical path cell body is accurately controlled to the set temperature by the optical path cell temperature controller to ensure that the temperature of the gas flowing into the optical path cell does not change; Step 3. Send the gas treated in step 2 to the sample purification and flow and pressure control system for treatment; Step 4: exhaust the gas in step 3.

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