In-situ water quality monitoring high-pressure resistant reaction device and cooling circulation system

Abstract

The application relates to a high-pressure-resistant reaction device and a cooling circulation system for in-situ water quality monitoring. The high-pressure-resistant reaction device comprises a reaction tube, a plugging assembly, a cooling and heat exchange assembly, a heating assembly and a fastening assembly. The plugging assembly comprises two plugs which are respectively plugged at two ends of the reaction tube, and each plug is provided with an inlet and outlet liquid channel and a limiting groove. The cooling and heat exchange assembly comprises a cooling jacket sleeved in the middle part of the reaction tube and a heat conduction sleeve pipe tightly sleeved on the outer wall of the reaction tube, heating cavities are formed between the two ends of the cooling jacket and the plugs, an annular groove on the inner wall of the cooling jacket and the outer wall of the reaction tube form a heat exchange cavity, and the heat conduction sleeve pipe is located in the heat exchange cavity and forms a cooling medium flow channel between the cooling jacket. The heating assembly comprises heating rings arranged in the two heating cavities respectively. The fastening assembly comprises end flanges for applying axial compression force to the plugs. The scheme realizes in-situ optical detection without sample transfer, and has high-temperature and high-pressure sealing reliability and high-efficiency cooling and heat exchange capacity.

Description

Technical Field

[0001] This application relates to the field of water quality monitoring equipment technology, specifically to a high-pressure resistant reaction device and a cooling circulation system for in-situ water quality monitoring. Background Technology

[0002] In the field of online water quality monitoring, in-situ digestion-detection technology is an important means of obtaining key indicators such as total phosphorus and total nitrogen in water bodies. This technology typically requires a chemical reaction between the water sample and the digestion reagent under high temperature and high pressure conditions within a sealed reaction tube. After the reaction is completed, spectral detection is performed through an optical window.

[0003] Existing in-situ reaction devices mostly use metal (such as stainless steel) reaction tubes with threaded plugs for sealing. This type of structure has the following drawbacks: the metal tube is opaque, requiring the sample to be transferred to a flow cell during testing, resulting in complex tubing connections, large dead volume, and the inability to directly observe the reaction process inside the tube in situ. Some devices use transparent quartz tubes to solve the light transmission problem, but during the high-temperature pressurization stage, the axial stress at the end of the quartz tube concentrates, making it prone to localized cracking, especially under frequent temperature fluctuations, making it difficult to guarantee the reliability of the end seal. Furthermore, after digestion, cooling to a suitable detection temperature range is required; conventional air cooling or natural cooling is inefficient, prolonging the single detection cycle and failing to meet the needs of high-frequency online monitoring. Summary of the Invention

[0004] The purpose of this application is to provide an in-situ water quality monitoring high-pressure resistant reaction device and a cooling circulation system, which can perform optical detection directly without transferring the sample, while improving the structural reliability of the reaction tube under high temperature and high pressure conditions and achieving efficient temperature control.

[0005] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0006] A high-pressure resistant reaction device for in-situ water quality monitoring includes a reaction tube, a plugging assembly, a cooling and heat exchange assembly, a heating assembly, and a fastening assembly. The plugging assembly includes two plugs, which are respectively plugged at both ends of the reaction tube. Each plug has an inlet / outlet channel communicating with the reaction tube along its axial centerline and a limiting groove for accommodating and fixing the end of the reaction tube. The cooling and heat exchange assembly is used to cool the reaction tube and the sample inside it. It includes a cooling jacket and a heat-conducting sleeve. The cooling jacket is fitted onto the middle outer wall of the reaction tube, and its upper and lower ends abut against the two plugs respectively. A heating cavity is formed between the end face of the cooling jacket and the plugs. A medium inlet and a medium outlet are provided on the side wall of the cooling jacket. An annular groove machined on the inner wall of the cooling jacket forms a heat exchange cavity with the outer wall of the reaction tube. The heat-conducting sleeve is fitted onto the outer wall of the reaction tube, located within the heat exchange cavity, and an annular cooling medium flow channel is formed between the outer wall of the heat-conducting sleeve and the cooling jacket. The cooling medium flow channel communicates with the medium inlet and the medium outlet. The heating assembly is used to heat the reaction tube and the sample inside it. It includes two heating rings, each located within a corresponding heating chamber. The fastening assembly includes two end flanges, which are fastened to the ends of two plugs to apply an axial clamping force toward the reaction tube, thereby creating a high-pressure seal between the plugs and the end faces of the reaction tube.

[0007] Furthermore, each plug includes a base and a positioning sleeve. A cylindrical plugging body is located in the center of the base, the outer diameter of which matches the inner diameter of the reaction tube. The plugging body has inlet and outlet channels along its axial centerline. A limiting groove is provided on the base. The positioning sleeve is a sleeve extending axially from the circumferential edge of the base along the reaction tube. The end of the positioning sleeve abuts against the cooling sleeve, and corresponding heating chambers are formed between the upper and lower end faces of the cooling sleeve, the outer wall of the reaction tube, and the inner walls of the two positioning sleeves.

[0008] Furthermore, the end flange is fitted around the outer periphery of the sealing body and abuts against the base. Under the action of the axial fasteners, the end flange applies axial clamping force to the base and the end face of the reaction tube.

[0009] Furthermore, a pressure-resistant ring is provided between the reaction tube and the limiting groove; the pressure-resistant ring is a polyether ether ketone sealing ring.

[0010] Furthermore, the end of the inlet / outlet channel that connects to the reaction tube forms an inverted conical structure. The inner diameter of the larger end of the inverted conical structure is the same as and flush with the inner diameter of the reaction tube, so as to eliminate the dead volume of fluid at the connection between the inlet / outlet channel and the reaction tube.

[0011] Furthermore, in the area between the cooling jacket and the upper plug, corresponding to the reaction tube, there is an unobstructed optical detection window.

[0012] Furthermore, it also includes a temperature sensor, which passes through a detection hole on the plug and contacts the heating ring to detect the temperature of the heating ring.

[0013] This application also provides a water quality monitoring cooling circulation system, including an instrument compartment, a circulation pump, a heat exchange pipeline, and any of the aforementioned reaction devices. The medium inlet is connected to the outlet of the circulation pump, the medium outlet is connected to the inlet of the heat exchange pipeline, and the outlet of the heat exchange pipeline is connected to the inlet of the circulation pump, forming a closed-loop heat dissipation circulation circuit.

[0014] This application has the following beneficial effects:

[0015] Because of the structure employing an end flange and plug mating, the end flange uses axial fasteners to press the plug axially against the end face of the reaction tube. The limiting groove provides radial constraint and axial positioning for the end of the reaction tube, ensuring that the end of the reaction tube is subjected to compression rather than bending or tension. The axial thrust generated during the high-temperature pressurization stage is transmitted to the end flange through the plug, and the reaction tube only bears compressive stress. Therefore, it effectively avoids rupture failure caused by stress concentration at the end of the reaction tube, improving the sealing reliability and service life of the device under high-temperature, high-pressure, and alternating hot and cold conditions.

[0016] Furthermore, by incorporating a heat-conducting sleeve within the cooling jacket and forming an annular cooling medium flow channel, the heat-conducting sleeve efficiently guides the heat from the center of the reaction tube to the heat exchange chamber. The cooling medium flows evenly across the outer wall of the heat-conducting sleeve within the annular flow channel, carrying heat as it exits through the medium outlet. This significantly increases the effective heat exchange area compared to direct cooling without a heat-conducting sleeve. Therefore, rapid cooling of the reaction tube and its contents can be achieved after digestion, shortening the single detection cycle.

[0017] Furthermore, because the inlet / outlet channel and the reaction tube connect to form an inverted conical structure, and the inner diameter of its larger end is the same as and flush with the inner diameter of the reaction tube, the flow channel cross-section achieves a smooth transition during the process of fluid entering or exiting the reaction tube from the inlet / outlet channel, without any low-velocity stagnation zone caused by sudden expansion or contraction. Therefore, the dead volume of fluid at the connection is eliminated, ensuring sufficient sample replacement.

[0018] Furthermore, because the heating ring is positioned within an independent heating cavity formed by the positioning sleeve, the end face of the cooling sleeve, and the outer wall of the reaction tube, the heating ring does not contact the cooling sleeve. The heat generated by the heating ring is concentrated on the two ends of the reaction tube, which are not covered by the cooling sleeve. This creates an unobstructed optical detection window on the reaction tube, sandwiched between the upper heating and cooling areas. Therefore, after digestion and cooling, transmission or scattering optical detection can be performed in situ on the same reaction tube without transferring the sample, simplifying the system flow path. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall external structure of the reaction device of this application;

[0020] Figure 2This is a schematic cross-sectional view of the reaction apparatus of this application;

[0021] Figure 3 This is an exploded view of the reaction tube and the sealing connection structure at both ends of this application;

[0022] Figure 4 for Figure 2 A partially enlarged schematic diagram of the end sealing connection structure at point A;

[0023] Figure 5 for Figure 2 A partially enlarged schematic diagram of the coolant flow and sealing structure at point B;

[0024] Figure 6 This is a sectional view of the reaction tube along the vertical direction in this application;

[0025] Figure 7 This is a schematic diagram of the heat exchange pipeline layout within the instrument compartment of this application.

[0026] Figure 8 This is a system block diagram of the water quality testing cooling circulation system in this application.

[0027] Reference numerals: 1. Reaction tube; 101. Optical detection window; 2. Plug; 21. Base; 22. Positioning sleeve; 211. Sealing body; 201. Liquid inlet / outlet channel; 202. Limiting groove; 203. Inverted conical structure; 204. Detection hole; 3. Cooling jacket; 301. Heating chamber; 302. Medium inlet; 303. Medium outlet; 304. Heat exchange chamber; 305. Cooling medium flow channel; 4. Heat-conducting sleeve; 5. Heating ring; 6. End flange; 61. Axial fastener; 7. Temperature detector; 8. Pressure ring; 9. Instrument compartment; 10. Circulating pump; 11. Heat exchange pipeline. Detailed Implementation

[0028] The embodiments of this application will now be described with reference to the accompanying drawings. It should be understood that the following embodiments are only for illustrating the technical solutions of this application and are not intended to limit the scope of protection of this application. Equivalent substitutions, conventional modifications, or combinations made by those skilled in the art based on this specification without departing from the concept of this application should all fall within the scope of protection of this application.

[0029] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] like Figure 1As shown in the figure, this embodiment provides a high-pressure resistant reaction device for in-situ water quality monitoring, which mainly includes a reaction tube 1, a sealing assembly, a cooling and heat exchange assembly, a heating assembly, and a fastening assembly. The reaction tube 1 is a transparent quartz glass tube with openings at both ends, arranged vertically. The cooling and heat exchange assembly is sleeved on the outer wall of its middle section, and the upper and lower ends are sealed by the sealing assembly. The fastening assembly applies an axial locking force to the sealing assembly and the reaction tube 1 to achieve a high-pressure seal.

[0031] like Figures 2-3 As shown, the reaction tube 1 is arranged vertically. The sealing assembly includes two identical plugs 2, which are respectively sealed at the upper and lower ends of the reaction tube 1. Since the two ends of the reaction tube 1 have the same structure, during in-situ water quality testing, the end facing the water surface is the upper end, and the end facing the bottom is the lower end. Each plug 2 is integrally formed from a base 21 and a positioning sleeve 22, or assembled from the base 21 and the positioning sleeve 22. A cylindrical sealing body 211 is provided in the middle of the base 21. The sealing body 211 has an inlet / outlet channel 201 that communicates with the reaction tube 1 along its axial centerline. The outer diameter of the sealing body 211 and the inner diameter of the reaction tube 1 are fitted with a clearance fit for easy assembly and sealing. An annular limiting groove 202 is machined on the end face of the base 21. The end of the reaction tube 1 is inserted into the limiting groove 202. The limiting groove 202 provides radial positioning and axial limiting for the reaction tube 1. The depth of the limiting groove 202 is set according to requirements, ranging from 2 to 5 mm, preferably 3.5 mm, but this embodiment does not impose a specific numerical limitation. A pressure-resistant ring 8 is provided between the bottom of the limiting groove 202 and the end face of the reaction tube 1. The pressure-resistant ring 8 is made of polyetheretherketone material and undergoes elastic deformation under axial compression force to fill the sealing gap. Optionally, the inner diameter of the pressure-resistant ring 8 is not less than the inner diameter of the reaction tube 1, and the inner edge of the pressure-resistant ring 8 does not protrude into the internal flow channel of the reaction tube 1 after being deformed by pressure. Furthermore, the groove wall of the limiting groove 202 limits the radial deformation of the pressure ring 8, so that the pressure ring 8 only undergoes axial compression and radial restricted expansion; the deformed pressure ring 8 maintains a gapless sealing state with the groove wall, bottom of the limiting groove 202 and the end face of the reaction tube 1, so as to prevent fluid from seeping out along the outer edge or end face of the pressure ring 8.

[0032] With the above structure, a reliable sealed connection can be formed at both ends of the reaction tube 1 to adapt to the high temperature, pressure changes and corrosive reagent environment that may exist in the in-situ water quality analysis process.

[0033] like Figures 3-6 As shown, the end of the inlet / outlet channel 201 that connects to the reaction tube 1 forms an inverted conical structure 203. The inverted conical structure 203 is the space enclosed by a conical surface that gradually expands in diameter from the circular cross-section of the inlet / outlet channel 201 to the inner diameter of the reaction tube 1. Figure 6In this design, the inner diameter of the larger end of the inverted conical structure 203 is equal to the inner diameter of the reaction tube 1, and its larger end port is flush with the inner wall surface of the end of the reaction tube 1, forming a smooth transition without steps. The liquid inlet / outlet channel 201 of the upper plug 2 serves as the liquid outlet, and the liquid inlet / outlet channel 201 of the lower plug 2 serves as the liquid inlet, through which samples and reagents enter and exit the reaction tube 1. This connection structure helps to reduce the dead volume at the end connection of the reaction tube and reduce sample or reagent residue.

[0034] Optionally, the aperture in the middle of the liquid inlet / outlet channel 201 is smaller, ranging from 0.5 to 2.0 mm, preferably 1.5 mm, while the aperture further away from the reaction tube 1 and in contact with the outside is larger, ranging from 3 to 10 mm, preferably 5.5 mm.

[0035] from Figure 2 As can be seen, the positioning sleeve 22 is a cylindrical structure extending axially from the circumferential edge of the base 21 along the reaction tube 1. The cylindrical structure can be called a sleeve, which is fitted around the outer periphery of the reaction tube 1, with a radial gap between the inner wall and the outer wall of the reaction tube 1. The end of the positioning sleeve 22 away from the base 21 abuts against the end face of the cooling sleeve 3.

[0036] from Figure 6 As can be seen, the cooling heat exchange assembly includes a cooling sleeve 3 and a heat-conducting sleeve 4. The cooling sleeve 3 is a hollow cylindrical sleeve made of PEEK material, fitted onto the outer wall of the middle part of the reaction tube 1. The upper end face of the cooling sleeve 3 abuts against the lower end face of the positioning sleeve 22 of the upper plug 2, and its lower end face abuts against the upper end face of the positioning sleeve 22 of the lower plug 2, the three together forming the outer contour of the axial middle section of the reaction tube 1. In this assembled state, the upper end face of the cooling sleeve 3, the outer wall of the reaction tube 1, and the inner wall of the positioning sleeve 22 of the upper plug 2 form the upper heating cavity 301; similarly, the lower end face of the cooling sleeve 3, the outer wall of the reaction tube 1, and the inner wall of the positioning sleeve 22 of the lower plug 2 form the lower heating cavity 301.

[0037] An annular groove is machined in the middle of the inner wall of the cooling jacket 3. The axial span of the annular groove is less than the total length of the cooling jacket 3, and the inner diameter of the annular groove is greater than the inner diameter of the rest of the cooling jacket 3. After the cooling jacket 3 is assembled, an annular heat exchange cavity 304 is formed between the bottom surface of the annular groove and the outer wall of the reaction tube 1. Inside the heat exchange cavity 304, the heat-conducting sleeve 4 is tightly fitted onto the outer wall of the reaction tube 1. The inner wall surface of the heat-conducting sleeve 4 is either interference-fitted with the outer wall surface of the reaction tube 1 or bonded with thermally conductive adhesive to ensure good heat conduction. Optionally, the heat-conducting sleeve is made of aluminum alloy. Optionally, the interference fit between the inner wall surface of the heat-conducting sleeve 4 and the outer wall surface of the reaction tube 1 can be 0.01~0.03 mm. The outer diameter of the heat-conducting sleeve 4 is smaller than the inner diameter of the heat exchange cavity 304, so that an annular cooling medium flow channel 305 is formed between the outer wall of the heat-conducting sleeve 4 and the bottom of the annular groove of the cooling jacket 3. The cooling medium flow channel 305 is arranged around the heat-conducting sleeve 4 in a complete circle, and its upper and lower ends are respectively closed by the upper and lower sidewalls of the annular groove, forming a flow annular cavity. Optionally, depending on the specific structural design, the cooling medium flow channel 305 can be an annular channel, a partially annular channel, or other closed heat exchange channels that cooperate with the outer periphery of the reaction tube 1. Optionally, sealing rings can also be provided on the upper and lower sides of the cooling medium flow channel 305 on the cooling sleeve 3.

[0038] like Figure 2 As shown, a medium inlet 302 is provided on one side of the outer wall of the cooling jacket 3, and a medium outlet 303 is provided on the other side. Both the medium inlet 302 and the medium outlet 303 penetrate the wall of the cooling jacket 3 radially and communicate with the cooling medium flow channel 305. The cooling medium (such as cold water) enters the cooling medium flow channel 305 from the medium inlet 302, flows along an annular path and sweeps across the outer wall of the heat-conducting sleeve 4, absorbs the heat conducted by the heat-conducting sleeve 4, and is discharged from the medium outlet 303.

[0039] like Figure 6 As shown, the heating assembly includes two heating rings 5, namely an upper heating ring and a lower heating ring. The upper heating ring is fitted onto the outer wall of the reaction tube 1, located within the upper heating chamber 301, and is tightly fitted against the outer wall of the reaction tube 1. The lower heating ring is fitted onto the outer wall of the reaction tube 1, located within the lower heating chamber 301, and is tightly fitted against the outer wall of the reaction tube 1. The heating rings 5 ​​use resistance wire heating elements and are connected to an external power supply or control unit via wires. After being energized, they heat the upper and lower ends of the reaction tube 1, causing the sample inside the tube to heat up and undergo a digestion reaction. The heating rings 5 ​​are characterized by their compact structure, fast heating response, and good electrical insulation performance, making them suitable for the miniaturized heating requirements inside in-situ water quality analyzers.

[0040] To achieve in-situ water quality detection, an unobstructed optical detection window 101 is formed on the outer wall of the reaction tube 1 in the area between the cooling sleeve 3 and the upper plug 2. Specifically, the area on the outer wall of the reaction tube 1 between the lower edge of the upper heating ring and the upper end of the cooling sleeve 3 is unobstructed by any component, forming the optical detection window 101. The axial height of the optical detection window 101 is 2 mm. Furthermore, the axial centerline of the optical detection window 101 is offset from the axial midpoint between the lower edge of the upper heating ring and the upper end of the cooling sleeve 3, and the optical detection window 101 is biased towards the upper end of the cooling sleeve 3 to reduce the influence of the heat radiation from the heating ring 5 on the detection optical path. The optical detection fiber or detector can be aligned with this window to detect transmitted or scattered light, reducing residues and errors caused by liquid transfer; at the same time, it facilitates the observation of changes in the sample inside the reaction tube 1.

[0041] like Figure 1 , 6 As shown, the fastening assembly includes two end flanges 6 and axial fasteners 61 that mate with them. The end flanges 6 have a central through-hole and are fitted around the outer periphery of the sealing body 211 of the base 21, with the inner end face of the flange abutting against the back end face of the base 21. The axial fasteners 61 are multiple double-ended studs evenly distributed along the circumference, with both ends passing through the bolt holes of the upper and lower end flanges 6 respectively, and are locked with nuts. When the nuts are tightened, the end flanges 6 apply an axial clamping force towards the back of the base 21 in the direction of the reaction tube 1. This force is transmitted through the base 21 to the limiting groove 202 and the pressure ring 8, ultimately forming a high-pressure seal between the two end faces of the reaction tube 1 and the upper and lower plugs 2 respectively.

[0042] The upper plug 2 is also provided with a detection hole 204. The thermocouple probe of the temperature detector 7 passes through the detection hole 204 and extends into the upper or lower heating cavity 301, contacting the outer surface of the heating ring 5. This is used to detect the temperature of the heating ring 5 in real time and feed it back to the temperature control system. This allows the control unit to adjust the heating power of the heating component or control the circulation state of the cooling medium of the cooling heat exchange component based on the measured temperature feedback, thereby achieving the adjustment of the temperature of the reaction tube 1. Since there is a heat conduction path between the heating ring 5 and the reaction tube 1 and the sample inside the tube, the temperature of the heating ring and the temperature of the sample inside the reaction tube have a corresponding relationship. A temperature compensation curve between the two can be established through pre-calibration. The control unit converts the detected heating ring temperature into the estimated temperature of the sample inside the reaction tube based on this compensation curve, and then adjusts the heating power or the flow rate of the cooling medium.

[0043] Optionally, the detection hole 204 can also be located on the lower plug 2. The thermocouple probe of the temperature detector 7 extends through the detection hole 204 into the lower heating chamber 301 and contacts the outer surface of the heating ring 5. The inner end of the detection hole 204 is closed and does not communicate with the liquid inlet / outlet channel 201 or the interior of the reaction tube 1.

[0044] This embodiment also provides a water quality monitoring and cooling circulation system.

[0045] like Figures 7-8 As shown, the system includes an instrument compartment 9, a circulating pump 10, heat exchange pipelines 11, and the reaction apparatus described in any of the above embodiments. The main body of the reaction apparatus is installed inside the instrument compartment 9. The instrument compartment 9 is an underwater sealed chamber with a sample channel only at its top. The interior is used to house the reaction apparatus, as well as to install the spectral detection module, control circuitry, etc.

[0046] Both the circulating pump 10 and the heat exchange pipeline 11 are located inside the instrument compartment 9. The heat exchange pipeline 11 is a section of serpentine coil or other type of pipe, installed on the inner wall of the instrument compartment 9, used for non-contact heat exchange with the external environment (such as lake water), and the other end is connected to the medium outlet 303 of the cooling jacket 3. Specifically, the outlet of the circulating pump 10 is connected to the medium inlet 302 on the side wall of the cooling jacket 3 through a pipeline; the medium outlet 303 is connected to one end of the heat exchange pipeline 11 through a pipeline; and the other end of the heat exchange pipeline 11 is connected to the inlet of the circulating pump 10. Thus, the medium inlet 302, the cooling medium flow channel 305, the medium outlet 303, the heat exchange pipeline 11, and the circulating pump 10 together form a closed heat dissipation circulation loop. Optionally, the heat exchange pipeline 11 passes through the coolant storage tank inside the instrument compartment, where heat exchange is achieved by the coolant inside the instrument.

[0047] When the digestion reaction is complete and cooling is required, the temperature control system activates the circulation pump 10. Driven by the circulation pump 10, the cooling medium enters the annular cooling medium channel 305 inside the cooling jacket 3 from the medium inlet 302, evenly sweeping across the outer wall of the heat-conducting sleeve 4, efficiently absorbing the heat conducted from the middle section of the reaction tube 1. The heated cooling medium flows out from the medium outlet 303 and enters the heat exchange pipeline 11. The heat exchange pipeline 11, in the form of a serpentine coil, significantly increases the contact area with the environment inside the instrument chamber 9 (or the instrument chamber wall), dissipating the carried heat to the external water body. The cooled cooling medium is then drawn back into the inlet of the circulation pump 10 to begin the next cycle. By controlling the speed and start / stop of the circulation pump 10, the cooling rate can be precisely adjusted, allowing the sample in the reaction tube 1 to rapidly cool from the high digestion temperature to a suitable temperature range for optical detection.

[0048] In a preferred embodiment, a thermally conductive interface material is coated between the heat exchange pipe 11 and the internal environment of the instrument compartment 9 to reduce contact thermal resistance and improve heat transfer efficiency. An anti-condensation insulation layer may also be fitted over the outside of the heat exchange pipe 11 to reduce the risk of condensation during operation of the low-temperature cooling medium and to reduce unnecessary heat exchange paths.

[0049] In this embodiment, during operation, the digestion reagent and the water sample to be tested enter the reaction tube 1 through the lower inlet / outlet channel 201, flow smoothly into the tube through the inverted conical structure 203, and after the reaction, the original fluid in the tube is extracted through the lower inlet / outlet channel 201 to avoid cross-contamination caused by dead volume. After sample injection, the valves of the upper and lower inlet / outlet channels 201 are closed (the valve closing method can be existing technology), and the heating ring 5 is energized to heat the two ends of the reaction tube 1, raising the temperature of the sample in the tube to the temperature required for digestion. After digestion, the cooling medium enters the cooling medium flow channel 305 through the medium inlet 302, sweeps across the outer wall of the heat-conducting sleeve 4, and carries away the heat in the middle section of the reaction tube 1, achieving rapid cooling of the sample in the tube. After cooling to the detection temperature, the optical detection system performs in-situ spectral detection of the reaction products in the tube through the optical detection window 101.

[0050] Because the inverted conical structure 203 at the connection between the inlet / outlet channel 201 and the reaction tube 1 is flush with the large end of the reaction tube 1, the flow channel cross-section transitions smoothly, eliminating dead zones in the flow volume and ensuring sufficient sample replacement. The end of the reaction tube 1 is axially pressed against the end flange 6 through the limiting groove 202, so that the quartz tube only bears axial pressure under high temperature and pressure conditions, avoiding cracking caused by local stress concentration. The heat-conducting sleeve 4 increases the heat exchange area, improves cooling efficiency, and shortens the detection cycle. The optical detection window 101 enables true in-situ detection without sample transfer. The closed-loop heat dissipation circulation uses external natural water as the final heat sink, which can improve the cooling efficiency of the reaction device and reduce the heat dissipation burden inside the instrument, eliminating the need for an additional refrigeration unit and achieving system compactness and low power consumption. Through the above structure, this application can achieve high-pressure sealing, reduced dead volume, rapid cooling, and long-term stable operation within the limited space of the in-situ water quality analyzer.

[0051] It should be noted that the materials, dimensions, flow rates, heating power, temperature setpoints, cooling medium types, and specific installation methods of each component in the above embodiments can all be adjusted according to the specific water quality analysis project and instrument structure. These adjustments should not be construed as limiting the scope of protection of this application.

Claims

1. A high-pressure resistant reaction device for in-situ water quality monitoring, characterized in that, include: Reaction tube (1); The sealing assembly includes two plugs (2) which are respectively sealed at both ends of the reaction tube (1). Each plug (2) has an inlet / outlet channel (201) communicating with the reaction tube (1) along its axial center line, and has a limiting groove (202) for accommodating and fixing the end of the reaction tube (1). A cooling heat exchange assembly for cooling the reaction tube (1) and the sample inside it includes a cooling sleeve (3) and a heat-conducting sleeve (4). The cooling sleeve (3) is fitted onto the outer wall of the middle part of the reaction tube (1), and its two ends abut against the two plugs (2) respectively. A heating chamber (301) is formed between the end face of the cooling sleeve (3) and the plugs (2). The side wall of the cooling sleeve (3) is provided with a medium inlet (302) and a medium outlet (303). The annular groove machined on the inner wall of the sleeve (3) forms a heat exchange cavity (304) with the outer wall of the reaction tube (1); the heat-conducting sleeve (4) is sleeved on the outer wall of the reaction tube (1) and located in the heat exchange cavity (304), and the outer wall of the heat-conducting sleeve (4) forms an annular cooling medium flow channel (305) with the cooling sleeve (3), and the cooling medium flow channel (305) is connected to the medium inlet (302) and the medium outlet (303); A heating assembly for heating the reaction tube (1) and the sample therein, comprising two heating rings (5), the two heating rings (5) being located in the corresponding heating chambers (301); The fastening assembly includes two end flanges (6), which are respectively fastened to the ends of the two plugs (2) for applying an axial clamping force toward the reaction tube (1) to the plugs (2) so that the plugs (2) and the end face of the reaction tube (1) form a high-pressure seal.

2. The high-pressure resistant reaction device for in-situ water quality monitoring according to claim 1, characterized in that, Each plug (2) includes: The base (21) has a cylindrical sealing body (211) in the middle, the outer diameter of the sealing body (211) is adapted to the inner diameter of the reaction tube (1), and the sealing body (211) has an inlet and outlet liquid channel (201) along its axial center line; the base (21) is provided with the limiting groove (202); A positioning sleeve (22) is a sleeve-shaped structure extending axially from the circumferential edge of the base (21) along the reaction tube (1); the end of the positioning sleeve (22) abuts against the cooling sleeve (3). The heating chamber (301) is formed between the end face of the cooling sleeve (3), the outer wall of the reaction tube (1), and the inner walls of the two positioning sleeves (22).

3. The high-pressure resistant reaction device for in-situ water quality monitoring according to claim 2, characterized in that, The end flange (6) is fitted around the outer periphery of the sealing body (211) and abuts against the base (21). Under the action of the axial fastener (61), the end flange (6) applies axial clamping force to the end face of the base (21) and the reaction tube (1).

4. The high-pressure resistant reaction device for in-situ water quality monitoring according to claim 3, characterized in that, A pressure-resistant ring (8) is provided between the reaction tube (1) and the limiting groove (202); the pressure-resistant ring (8) is made of polyether ether ketone material.

5. The high-pressure resistant reaction device for in-situ water quality monitoring according to claim 1, characterized in that, The inlet / outlet channel (201) is connected to the reaction tube (1) at one end to form an inverted conical structure (203). The inner diameter of the large end of the inverted conical structure (203) is the same as the inner diameter of the reaction tube (1) and is flush with it.

6. The high-pressure resistant reaction device for in-situ water quality monitoring according to claim 1, characterized in that, In the area between the cooling sleeve (3) and the upper plug (2), an unobstructed optical detection window (101) is formed on the outer wall of the reaction tube (1).

7. The high-pressure resistant reaction device for in-situ water quality monitoring according to claim 1, characterized in that, It also includes a temperature detector (7), which passes through the detection hole (204) on the plug (2) and contacts the heating ring (5) to detect the temperature of the heating ring (5).

8. A water quality monitoring and cooling circulation system, characterized in that, include: Instrument compartment (9); Circulating pump (10); Heat exchange piping (11) is used for heat exchange with the external environment; And the reaction apparatus as described in any one of claims 1 to 7; The medium inlet (302) is connected to the outlet of the circulating pump (10), the medium outlet (303) is connected to the inlet of the heat exchange pipeline (11), and the outlet of the heat exchange pipeline (11) is connected to the inlet of the circulating pump (10), forming a closed heat dissipation circulation loop.

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