A steam dryness measuring device

Abstract

This invention discloses a steam dryness measurement device, relating to the field of dryness measurement technology. The invention includes a flow test tube, an acoustic wave measurement component, a flow velocity adjustment component, and a photoelectric detection component. An acoustic wave generator and receiver are flush-mounted within the inner wall of the flow test tube. The sound velocity of the steam mixture is obtained by measuring the sound wave propagation time. The steam flow velocity is measured using an impeller anemometer and used for sound velocity compensation. Combined with data measured by pressure and temperature sensors, and utilizing the Wood-type mixed acoustic equation, the steam volume fraction and dryness are calculated, achieving real-time, high-precision, and non-destructive detection of steam dryness.

Description

Technical Field

[0001] This invention relates to the field of dryness measurement technology, specifically to a steam dryness measuring device. Background Technology

[0002] In SAGD oil sands mining, steam injection is an essential part of the production process, and steam is also a crucial element. The higher the dryness of the steam, the lower the water content during the oil extraction process, which will also affect the water content in subsequent crude oil metering. Therefore, the development of a convenient and effective steam dryness measurement device plays a key role in the process control of the extraction process and crude oil metering. The existing technology uses the condensation method to measure steam dryness. However, the condensation method relies on the mass ratio of the liquid phase after condensation to infer the steam dryness. Although the measurement is accurate, it requires steam sampling and cooling, which has the problems of slow response and strong destructiveness, and is not suitable for continuous online monitoring. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides the following technical solution: a steam dryness measuring device, comprising a flow test tube, a velocity measuring unit fixedly installed at one end of the flow test tube, and a sound wave generator and a sound wave receiver fixedly installed on both sides of the inner wall of the flow test tube, wherein the sound wave receiver is used to receive the sound wave signal emitted by the sound wave generator; a pressure sensor and a temperature sensor are also provided inside the flow test tube; wherein the pressure sensor, temperature sensor, sound wave generator, and sound wave receiver are all flush with the inner wall surface of the flow test tube. The velocity measuring unit includes an adjusting tube fixedly connected to the flow test tube coaxially, and multiple pressure guide ports are evenly opened on the circumferential surface of the adjusting tube; elastic ring plates are fixedly installed on the inner wall of the adjusting tube at the positions of all pressure guide ports; the velocity measuring unit also includes an impeller anemometer, which is used to directly measure the steam flow velocity.

[0004] Preferably, the inner wall of the regulating tube is provided with a groove for accommodating the elastic ring, so that the inner wall of the elastic ring is flush with the inner wall of the regulating tube, and the circumferential surface of the regulating tube is fixedly and sealed with a sealing cover ring on the outside of all pressure guide ports.

[0005] Preferably, a piston cylinder is fixedly connected to the sealing ring, and a regulating electric cylinder is fixedly installed on the piston cylinder. A piston block is fixedly installed at the end of the telescopic rod of the regulating electric cylinder, and the piston block is slidably sealed on the inner wall of the piston cylinder.

[0006] Preferably, flange connection plates are fixedly installed on both the flow test tube and the regulating tube.

[0007] Preferably, the regulating tube is provided with a first air pressure channel and a second air pressure channel along its radial direction, and the first air pressure channel and the second air pressure channel are located on both sides of the elastic ring; a pressure ball is fixedly installed above the first air pressure channel and the second air pressure channel, and the inner wall of the pressure ball is divided into two independent spaces by an elastic diaphragm.

[0008] Preferably, the pressure ball is provided with a sliding conductive rod in a sliding seal in the radial direction. The sliding conductive rod passes through the center of the pressure ball and is fixedly engaged with the center of the elastic diaphragm.

[0009] Preferably, a conductive brush is fixedly installed on the outer surface of the pressure ball, which is in conductive sliding cooperation with the sliding conductive rod. One end of the sliding conductive rod is connected in series with the conductive brush in a DC circuit. The relative positional relationship between the sliding conductive rod and the conductive brush, that is, the displacement of the sliding conductive rod, is determined by judging the current in the circuit.

[0010] Preferably, a limiting ring and a reflective lens are fixedly installed at both ends of the sliding conductive rod, wherein the end of the sliding conductive rod located in the direction of the reflective lens extends into the interior of the dark box, the dark box is fixedly installed on the flow test tube, and a beam emitter and an image sensor are fixedly installed on the inner wall of the dark box, and the light emitted by the beam emitter can be reflected onto the image sensor through the reflective lens.

[0011] Compared with the prior art, the present invention has the following advantages: (1) The present invention achieves sound velocity compensation by installing the sound wave generator and receiver flush in the flow test tube and combining them with the flow velocity measurement unit. This reduces the sound velocity offset error caused by the relative motion of the flowing steam, and can correct the propagation time difference in real time, thereby improving the accuracy and stability of the dryness calculation; (2) The present invention continuously monitors the steam dryness under the system operation state, avoiding the destructive sampling of the condensation method and the response lag of the throttling method; (3) The present invention adopts the Wood-type hybrid acoustic equation combined with the density equation, which can solve the steam volume fraction and mass dryness from the three physical quantities of sound velocity, pressure and temperature, avoiding the limitations of single-variable empirical fitting. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0013] Figure 2 This is a schematic diagram of the internal structure of the dark box of the present invention.

[0014] Figure 3 For the present invention Figure 2 Schematic diagram of the structure at point A in the middle.

[0015] Figure 4 This is a schematic diagram of the flow test tube structure of the present invention.

[0016] Figure 5 For the present invention Figure 4 Schematic diagram of the structure at point B.

[0017] Figure 6 This is a schematic diagram of the structure of the elastic ring plate of the present invention.

[0018] In the diagram: 101-Flow test tube; 102-Flange connection plate; 103-Dark box; 104-Adjusting tube; 105-Sealing cover ring; 106-Elastic ring plate; 107-First air pressure channel; 108-Second air pressure channel; 109-Piston cylinder; 110-Pressure guide port; 111-Control electric cylinder; 112-Piston block; 113-Sound wave generator; 114-Sound wave receiver; 115-Image sensor; 116-Beam emitter; 117-Reflecting mirror; 118-Pressure ball; 119-Elastic diaphragm; 120-Sliding conductive rod; 121-Conductive brush; 122-Limiting ring. Detailed Implementation

[0019] The following is in conjunction with the appendix Figures 1-6 The technical solution of the present invention will be further illustrated through specific embodiments.

[0020] This invention provides a steam dryness measuring device, including a flow test tube 101. A speed measuring unit is fixedly installed at one end of the flow test tube 101. A sound wave generator 113 and a sound wave receiver 114 are fixedly installed on both sides of the inner wall of the flow test tube 101, respectively. The sound wave receiver 114 is used to receive the sound wave signal emitted by the sound wave generator 113. A pressure sensor and a temperature sensor are also provided inside the flow test tube 101. The pressure sensor, temperature sensor, sound wave generator 113, and sound wave receiver 114 are all flush with the inner wall surface of the flow test tube 101. The speed measuring unit includes an adjusting tube 104 that is coaxially and fixedly connected to the flow test tube 101. Multiple pressure guide ports 110 are evenly opened on the circumferential surface of the adjusting tube 104. An elastic ring plate 106 is fixedly installed on the inner wall of the adjusting tube 104 at the positions of all the pressure guide ports 110. The speed measuring unit also includes an impeller anemometer, which is used to directly measure the steam flow rate. The inner wall of the regulating pipe 104 is provided with a groove for accommodating the elastic ring 106, so that the inner wall of the elastic ring 106 is flush with the inner wall of the regulating pipe 104. A sealing cover ring 105 is fixedly and sealed on the outer side of all pressure guide ports 110 on the circumferential surface of the regulating pipe 104. A piston cylinder 109 is fixedly and connected to the sealing cover ring 105. A regulating electric cylinder 111 is fixedly installed on the piston cylinder 109. A piston block 112 is fixedly installed at the end of the telescopic rod of the regulating electric cylinder 111. The piston block 112 is slidably and sealingly disposed on the inner wall of the piston cylinder 109. Flange connecting plates 102 are fixedly installed on both the flow test pipe 101 and the regulating pipe 104. A first air pressure channel 107 and a second air pressure channel 108 are arranged radially on the regulating tube 104, and are located on both sides of the elastic ring 106. A pressure ball 118 is fixedly installed above the first air pressure channel 107 and the second air pressure channel 108, and the inner wall of the pressure ball 118 is divided into two independent spaces by an elastic diaphragm 119. A sliding conductive rod 120 is slidably and sealingly inserted into the radial direction of the pressure ball 118, and the sliding conductive rod 120 passes through the center of the pressure ball 118. The sliding conductive rod 120 is fixedly engaged with the center of the elastic diaphragm 119. A conductive brush 121 is fixedly installed on the outer surface of the pressure ball 118 and is conductively and slidably engaged with the sliding conductive rod 120. One end of the sliding conductive rod 120 is connected in series with the conductive brush 121 in a DC circuit. The relative positional relationship between the sliding conductive rod 120 and the conductive brush 121, that is, the displacement of the sliding conductive rod 120, is determined by judging the current in the circuit.Limiting rings 122 and reflective mirrors 117 are fixedly installed at both ends of the sliding conductive rod 120, with one end of the sliding conductive rod 120 extending into the interior of the dark box 103 in the direction of the reflective mirror 117. The dark box 103 is fixedly installed on the flow test tube 101. A beam emitter 116 and an image sensor 115 are fixedly installed on the inner wall of the dark box 103. The light emitted by the beam emitter 116 can be reflected onto the image sensor 115 through the reflective mirror 117.

[0021] The working principle of the steam dryness measuring device disclosed in this invention is as follows: A flow test tube 101 (including a regulating tube 104) is connected in series in the pipeline (steam transport pipeline) whose steam dryness is to be measured via a flange connection plate 102. Steam is a mixture of water vapor and water droplets. Completely vaporized steam: entirely gaseous with no liquid droplets, called dry saturated steam, dryness = 1 (100% dry); entirely liquid water: not yet vaporized, called saturated liquid, dryness = 0 (0% dry); two-phase coexistence (partial vaporization): water and steam are mixed together, such as the white mist seen when a boiler just boils, which is wet steam, with a dryness between 0 and 1. A sound wave generator 113 emits sound waves, which are then received by a sound wave receiver 114. Since the distance between the sound wave generator 113 and the sound wave receiver 114 is fixed, the propagation speed of the sound wave in the steam can be determined by the propagation time of the sound wave. Meanwhile, since the steam is flowing, it needs to be compensated. At this time, the steam flow velocity is directly measured by the impeller anemometer. That is, the direction of steam flow and the direction of sound wave propagation will be deviated, resulting in the actual propagation path not being the distance between the sound wave generator 113 and the sound wave receiver 114.

[0022] The method for measuring steam dryness is as follows (the pressure and temperature inside the flow test tube 101 are detected by the corresponding pressure sensor and temperature sensor, and it is necessary to ensure that they are under the same pressure environment):

[0023] : The measured speed of sound of the steam mixture (m / s); , The sound velocity (m / s) of the gas phase (steam) and the liquid phase (water) at the corresponding pressure / temperature of the measuring point are standard data that have been measured in advance and can be found by referring to the table. , : Gas phase density and liquid phase density at the corresponding measuring point pressure / temperature (kg / m³) 3 These are standard data that have been measured in advance; you only need to look them up in the table. Volume fraction (gas phase volume fraction, 0–1); Average density of the mixture (kg / m³) 3 ); Dryness (mass fraction), which is the ratio of gaseous mass to total mass (0–1).

[0024] Wood-type hybrid acoustic equations (volume model):

[0025]

[0026] The acoustic compressibility of the mixture is related to the volume fraction of each phase. The left side is the reciprocal of the overall compressibility of the mixture, and the right side is the compressibility of each phase in parallel by volume fraction (Wood model).

[0027] Formula for density of steam mixture:

[0028]

[0029] Volume fraction Convert to average density of mixture The volume-weighted density (not mass fraction) is obtained by weighting the densities of the two phases according to their volume fraction. Unit: kg / m³ 3 .

[0030] The single-variable equation after elimination (used to find α after solving the simultaneous equations):

[0031]

[0032] Relationship between dryness and volume fraction:

[0033]

[0034] Volume fraction Convert to dryness (mass fraction) Mass ratio = gas phase mass / total mass. Gas phase mass = volume fraction × gas phase density (within the same unit volume); then divide by the total mass.

[0035] If the density of the steam mixture is known, the dryness fraction can be calculated directly:

[0036]

[0037] Since the sound velocity of steam varies with different dryness fractions, the density of the steam mixture can be roughly determined directly by the sound velocity. Controlling the regulating electric cylinder 111 causes its extension rod to move the piston block 112. The piston block 112 pushes the hydraulic oil inside the piston cylinder 109 into the sealing ring 105 (the sealing ring 105 and the piston cylinder 109 have a connected oil flow). This pressure causes the elastic ring 106 to deform (the two edges of the elastic ring 106 are fixed to the regulating pipe 104, causing the central part to bulge and deform). Like inflating a balloon, the deformation of the elastic ring 106 reduces the cross-sectional area of ​​the regulating pipe 104. At this point, the elastic ring 106 hinders the flow of steam, resulting in a pressure difference between the two sides of the elastic ring 106. The faster the flow rate, the greater the pressure difference (more steam is blocked by the elastic ring 106, which is related to the density of the steam mixture). (At the same flow rate, the greater the density of the steam mixture, the greater the pressure difference). Therefore, the pressure inside the first pressure channel 107 and the second pressure channel 108 will be different. This will cause a pressure difference between the two spaces separated by the elastic diaphragm 119 inside the pressure ball 118. The elastic diaphragm 119 will deform, causing the sliding conductive rod 120 to move. The sliding conductive rod 120 will slide relative to the conductive brush 121. The displacement of the sliding conductive rod 120 can be determined by the corresponding resistance value. Since the elastic diaphragm 119 is elastic, the pressure difference inside the first pressure channel 107 and the second pressure channel 108, i.e., the pressure difference on both sides of the elastic ring 106, can be determined by the displacement of the sliding conductive rod 120, thus obtaining the steam flow rate. Then, the regulating cylinder 111 can be controlled to reset the elastic ring 106 (depending on the requirements; if reset is not needed, i.e., to consistently detect the steam flow rate, reset can be performed; reset can reduce obstruction to steam flow). In addition, the movement of the sliding conductive rod 120 also causes the reflector 117 to move. Since the angle of the light emitted by the beam emitter 116 onto the reflector 117 does not change, the movement of the reflector 117 changes the position of the light spot reflected onto the image sensor 115. The displacement of the sliding conductive rod 120 is determined by the information of the light change received by the corresponding pixels on the image sensor 115 (size of a single pixel x number of pixels). This information is then compared with the steam velocity measured by the impeller anemometer and the steam velocity measured by the pressure difference method to determine the approximate density of the steam mixture. Specifically, the steam velocity is measured by the impeller anemometer, while the steam velocity measured by the pressure difference is related to the density of the steam mixture. For example, at a certain gas density, the measured velocities are the same, but the difference changes as the density of the steam mixture changes.

[0038] It should be noted that solving the equation may yield two solutions, both satisfying the mathematical relationship. However, physically, the appropriate solution needs to be selected based on the actual working conditions. For steam pipelines, the solution typically selected is... A large solution means that the volume is almost entirely gas, but the mass still contains a liquid phase.

Claims

1. A steam quality measuring device, characterized by: The flow test tube (101) is fixedly installed with a speed measuring part at one end, and sound wave generators (113) and sound wave receivers (114) are fixedly installed on the inner walls of the flow test tube (101) on both sides, wherein the sound wave receivers (114) are used for receiving sound wave signals emitted by the sound wave generators (113); The flow test tube (101) is further provided with a pressure sensor and a temperature sensor inside; The pressure sensor, the temperature sensor, the sound wave generator (113) and the sound wave receiver (114) are flush with the inner wall surface of the flow test tube (101); The speed measuring part comprises an adjusting tube (104) coaxially fixedly communicated with the flow test tube (101), a plurality of pressure guide ports (110) are uniformly formed on the circumferential surface of the adjusting tube (104), and an elastic ring piece (106) is fixedly arranged on the inner wall of the adjusting tube (104) at the position of all the pressure guide ports (110); the adjusting tube (104) is provided with a first air pressure channel (107) and a second air pressure channel (108) along the radial direction of the adjusting tube (104), and the first air pressure channel (107) and the second air pressure channel (108) are arranged on the two sides of the elastic ring piece (106); a pressure ball (118) is fixedly and communicatively arranged above the first air pressure channel (107) and the second air pressure channel (108), the inner wall of the pressure ball (118) is divided into two independent spaces by an elastic diaphragm (119); a sliding conductive rod (120) is slidingly and sealingly inserted into the pressure ball (118) in the radial direction of the pressure ball (118), the sliding conductive rod (120) penetrates the center of the pressure ball (118), and the sliding conductive rod (120) is fixedly connected with the center of the elastic diaphragm (119); limit rings (122) and mirror pieces (117) are fixedly installed at the two ends of the sliding conductive rod (120), respectively, wherein the end of the sliding conductive rod (120) located in the direction of the mirror piece (117) extends into the inside of a dark box (103) fixedly installed on the flow test tube (101), and the inner wall of the dark box (103) is fixedly installed with a light beam emitter (116) and an image sensor (115); the light emitted by the light beam emitter (116) can be reflected to the image sensor (115) through the mirror piece (117); The speed measuring part further comprises an impeller anemometer for directly measuring the flow rate of the steam.

2. A device for measuring the steam quality as claimed in claim 1, wherein: The inner wall of the adjusting tube (104) is provided with a groove for accommodating the elastic ring piece (106), so that the inner wall of the elastic ring piece (106) is flush with the inner wall of the adjusting tube (104), and the circumferential surface of the adjusting tube (104) is fixedly and sealingly sleeved with a sealing cover ring (105) outside all the pressure guide ports (110).

3. A device for measuring the steam quality as claimed in claim 2, wherein: A piston cylinder (109) is fixedly and communicatively arranged on the sealing cover ring (105), a control electric cylinder (111) is fixedly installed on the piston cylinder (109), a piston block (112) is fixedly installed at the end of the telescopic rod of the control electric cylinder (111), and the piston block (112) is slidingly and sealingly arranged on the inner wall of the piston cylinder (109).

4. A device for measuring the steam quality as claimed in claim 3, wherein: The flange connecting disc (102) is fixedly installed on the flow test pipe (101) and the adjusting pipe (104).

5. A device for measuring the steam quality as claimed in claim 4, wherein: The outer surface of the pressure ball (118) is fixedly installed with the conductive brush (121) which is in conductive sliding fit with the sliding conductive rod (120), and one end of the sliding conductive rod (120) is in series with the conductive brush (121) in the direct current circuit.

Images