System for testing chlorine oxidation resistance of plastic pipe in high-temperature internal-pressure fluid

Abstract

The utility model relates to a system for testing chlorine oxidation resistance of a plastic pipe in a high-temperature internal-pressure fluid, which comprises a pretreatment device, a temperature control device and a control device, the pressure pump is used for receiving the preheated fluid and boosting the pressure of the preheated fluid; the heating device is used for reheating the pressurized and preheated fluid to 100 DEG C or above; the constant-temperature test device is provided with a test box body, and a plurality of test pipe fittings are arranged in the constant-temperature test device along the vertical direction; and the post-treatment device is used for cooling the high-temperature internal pressure fluid from the constant-temperature test device, and the cooled fluid is circulated to the pretreatment device through a pipeline. The system can ensure that the temperature breaks through the limitation of 100 DEG C while the water solution entering the plastic pipe is kept in a liquid state, realizes automatic water replenishing and real-time monitoring and control on the temperature, pressure, pH, ORP and residual chlorine of the test fluid, and realizes one-key starting unmanned intelligent operation.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic pipe testing, and particularly relates to a chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids. Background Art

[0002] Plastic pipes such as PE pipes and PPR pipes have the advantages of good corrosion resistance, low use cost, convenient installation and maintenance compared with metal pipes, and have become one of the main pipes for fluid transportation such as tap water and the cold source of nuclear power plants. However, in order to meet the drinking water standard or prevent microbial corrosion and blockage, about 3 PPM of sodium hypochlorite is added to the transported water. However, sodium hypochlorite has strong oxidizing properties and will affect the service life of the pipe. In order to evaluate the service life of the pipe and accelerate the evaluation of the service life of the pipe, a chlorine oxidation resistance test system needs to be developed. However, the current chlorine oxidation resistance test system heats the aqueous solution in the test pipe in the atmospheric environment, resulting in the temperature of the aqueous solution introduced into the test pipe not being able to break through 100°C, making it difficult to simulate the chlorine oxidation effect in a high-temperature and high-pressure environment, and the intelligence of the test system is also insufficient. For example, it cannot automatically detect and control parameters such as the pH value, ORH, and residual chlorine concentration in the aqueous solution, resulting in a relatively large amount of manpower required for the test. Therefore, how to develop an automated system that can break through the traditional temperature limit (i.e., exceed 100°C) and realize the chlorine oxidation resistance test of plastic pipes in a high-temperature internal pressure environment is an urgent problem to be solved at present. Summary of the Utility Model

[0003] Aiming at the problems existing in the prior art, the purpose of the utility model is to provide a chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids, including a pretreatment device, a pressure pump, a temperature-raising device, a constant-temperature test device, and a post-treatment device arranged in series. This system can ensure that the aqueous solution entering the plastic pipe breaks through the 100°C limit while remaining in a liquid state, reaches and meets the 115°C aqueous solution high-temperature test conditions specified by industry standards, and realizes automatic water replenishment and real-time monitoring and control of the temperature, pressure, pH, ORP, and residual chlorine of the aqueous solution, achieving unmanned intelligent operation.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids, comprising: a pretreatment device for preheating the test fluid to below 95°C to obtain preheated fluid, and having a first liquid inlet for receiving the test fluid and a first liquid outlet for discharging the preheated fluid; a pressure pump for receiving the preheated fluid and boosting its pressure to obtain pressurized preheated fluid; a heating device for reheating the pressurized preheated fluid to above 100°C to obtain high-temperature internal pressure fluid, the heating device including a heating cavity and a first spiral coil disposed inside the heating cavity, the side of the heating cavity having a second liquid inlet for receiving the pressurized preheated fluid and a second liquid outlet for discharging the high-temperature internal pressure fluid, the two ends of the first spiral coil being respectively fluid-connected to the second liquid inlet and the second liquid outlet, and the two ends of the heating cavity respectively having a heat medium inlet and a heat medium outlet for circulating the heating medium; a constant-temperature test device having a test chamber, the two sides of the test chamber being respectively configured with a plurality of third liquid inlets for receiving the high-temperature internal pressure fluid and a plurality of third liquid outlets for discharging the high-temperature internal pressure fluid, and a plurality of test pipe fittings being arranged side by side at a certain interval along the vertical direction inside it, the two ends of the test pipe fittings being respectively connected to the third liquid inlets and the third liquid outlets; a post-treatment device for cooling the high-temperature internal pressure fluid from the constant-temperature test device to obtain cooled fluid, and having a plurality of fourth liquid inlets for receiving the high-temperature internal pressure fluid and a plurality of fourth liquid outlets for discharging the cooled fluid, and a cooler being configured inside it, wherein the cooled fluid is circulated to the pretreatment device through a pipeline.

[0006] Further, the pretreatment device has a pretreatment chamber, the side of the pretreatment chamber having a chemical dosing port for adding acetic acid and sodium hypochlorite and a cleaning port for discharging the test fluid, the top of the pretreatment chamber being configured with a water replenishment tank for supplementing the test fluid and its side being configured with a detection and control box.

[0007] Further, a plurality of first conveying pipelines are arranged between the heating device and the constant-temperature test device, the second liquid outlet is communicated with the third liquid inlet through the first conveying pipeline, and a pressure regulating valve, a pressure gauge and a shut-off valve are sequentially arranged on the first conveying pipeline.

[0008] Further, one side or both sides of the test chamber are open and are detachably configured with a chamber door, the bottom of the test chamber being configured with a base, and its sides being respectively configured with a gas inlet for receiving constant-temperature gas and a gas outlet for discharging constant-temperature gas.

[0009] Further, the plurality of test pipe fittings in the test chamber are arranged in parallel in the horizontal direction and are fluid-connected.

[0010] Furthermore, the test pipe fitting includes a pair of fixing parts, a pair of clamping parts and a pipe body. The pair of fixing parts are respectively arranged on the third liquid inlet and the third liquid outlet. The pair of clamping parts are respectively fixed at the ends of the fixing parts. Both ends of the pipe body are detachably arranged on the clamping parts.

[0011] Furthermore, the post-treatment device has a water return tank body and a conveying cylinder arranged on the top of the water return tank body. The plurality of fourth liquid inlets are arranged at certain intervals along the vertical direction of the conveying cylinder. The fourth liquid outlet is arranged on the side of the water return tank body. A plurality of second conveying pipelines are arranged between the constant temperature test device and the post-treatment device. The third liquid outlet is communicated with the fourth liquid inlet through the second conveying pipeline. A one-way valve and a flow regulating valve are sequentially arranged on the second conveying pipeline.

[0012] Furthermore, the cooler is located in the conveying cylinder and has a second spiral coil pipe. The cold medium inlet of the second spiral coil pipe is fixed on the top of the conveying cylinder, and the cold medium outlet is fixed on the side of the water return tank body, for connecting a cooling medium to reduce the temperature of the high-temperature internal pressure fluid.

[0013] Furthermore, the temperature of the high-temperature internal pressure fluid is 105°C or 115°C, and the temperature of the cooling fluid is less than 100°C.

[0014] Furthermore, a control system is also configured. The control system is respectively communicatively connected with the pretreatment device, the pressure pump, the heating device, the constant temperature test device and the post-treatment device.

[0015] The utility model has the following advantages:

[0016] 1. The utility model is a system for testing the chlorine oxidation resistance of plastic pipes in high-temperature internal pressure fluids, including a pretreatment device, a pressure pump, a heating device, a constant temperature test device and a post-treatment device arranged in series. This system can ensure that the aqueous solution entering the plastic pipe breaks through the limit of 100°C while remaining in a liquid state, reaches and meets the 115°C aqueous solution high-temperature test conditions specified by industry standards, and realizes automatic water replenishment and real-time monitoring and control of the temperature, pressure, pH, ORP, and residual chlorine of the test fluid, achieving unmanned intelligent operation.

[0017] 2. The present utility model realizes the recycling of heating and cooling of the test fluid during the test process by configuring a heating device and a cooler. The heating device can heat the test fluid to above 100°C, so that the test tube is filled with high-temperature liquid and its chlorine oxidation resistance is tested. The cooler cools the test fluid to prevent the vaporization of high-pressure liquid due to pressure drop, ensuring that the aqueous solution can smoothly flow back to the pretreatment device through the circulation water pipe. This not only reduces energy consumption but also decreases the demand for water resources, reflecting the environmental protection concept of energy conservation and emission reduction. At the same time, the recycling of the test fluid also reduces wastewater discharge, which is beneficial to environmental protection.

[0018] 3. Through the coordinated operation of the pretreatment device and the control system, the present utility model ensures the precise control of the temperature of the test fluid. The test fluid can be preheated in the makeup water tank to keep its temperature consistent with that of the test fluid in the pretreatment box, avoiding the water temperature fluctuation caused by water replacement, thereby improving the accuracy and reliability of the test.

[0019] 4. By the combined use of an external chemical dosing tank and a detection control box, and combined with the automatic control function of the control system, the present utility model realizes the real-time automatic detection and adjustment of the pH, ORP, and residual chlorine content of the test fluid. This not only reduces the burden of manual operation but also improves the accuracy and efficiency of detection, ensuring the accuracy and reliability of the test results. Description of the Drawings

[0020] Figure 1 is a three-dimensional structural schematic diagram of the system for testing the chlorine oxidation resistance of plastic pipes in high-temperature internal pressure fluid of the present utility model.

[0021] Figure 2 is a three-dimensional structural schematic diagram of another angle of the system for testing the chlorine oxidation resistance of plastic pipes in high-temperature internal pressure fluid of the present utility model.

[0022] Figure 3 is a three-dimensional structural schematic diagram of the pretreatment device of the present utility model.

[0023] Figure 4 is a three-dimensional structural schematic diagram of the pressure pump and the heating device of the present utility model.

[0024] Figure 5 is a three-dimensional sectional view of the heating device of the present utility model.

[0025] Figure 6 is a three-dimensional sectional view of the constant temperature test device of the present utility model.

[0026] Figure 7 is a three-dimensional structural schematic diagram of the test pipe fitting of the present utility model.

[0027] Figure 8It is a three-dimensional sectional view of the post-treatment device of the present utility model.

[0028] Figure 9 It is a three-dimensional structural schematic diagram of the cooler of the present utility model.

[0029] Among them, 1 is a pretreatment device, 101 is a pretreatment box body, 101a is a first liquid inlet, 101b is a first liquid outlet, 101c is a chemical addition port, 101d is a cleaning port, 102 is a water replenishing tank, 103 is a detection and control box, 2 is a pressure pump, 3 is a heating device, 301 is a heating cavity, 301a is a second liquid inlet, 301b is a second liquid outlet, 301c is a heat medium inlet, 301d is a heat medium outlet, 302 is a first spiral coil, 4 is a constant temperature test device, 401 is a test box body, 401a is a third liquid inlet, 401b is a third liquid outlet, 401c is a gas outlet, 401d is a gas inlet, 402 is a test pipe fitting, 402a is a fixing part, 402b is a clamping part, 402c is a pipe body, 403 is a box door, 404 is a base, 5 is a post-treatment device, 501 is a return water tank body, 501a is a fourth liquid outlet, 502 is a conveying cylinder, 502a is a fourth liquid inlet, 503 is a cooler, 503a is a second spiral coil, 503a1 is a cold medium inlet, 503a2 is a cold medium outlet, 6 is a first conveying pipeline, 601 is a pressure regulating valve, 602 is a pressure gauge, 603 is a cut-off valve, 7 is a second conveying pipeline, 701 is a check valve, 702 is a flow regulating valve, 8 is a support device, 801 is a support frame, 801a is a bottom plate, 801b is a partition board, 801c is a support foot, 801d is a pulley, 802 is an extension plate, 803 is a support column, 9 is a circulating water pipe. Specific embodiments

[0030] The following description is merely exemplary in nature and is in no way intended to limit the present utility model, its applications, or uses. It will be further understood that the terms "comprising" and / or "including" when used in this specification specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be understood that when an element, component, and / or part is referred to as being "connected to another element, component, and / or part", it can be directly connected to the other element, component, and / or part, or intervening elements may be present. It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, components, and / or parts, these elements, components, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, or part from another. Thus, the first element, component, or part discussed below may be referred to as the second element, component, or part without departing from the teachings of the present utility model. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the present utility model belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant art and / or the context of this specification, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0031] It should be understood that for the sake of clearly showing the content therein, the drawings herein are not drawn to scale, and the same or similar reference numerals indicate the same or similar components or parts. In addition, it should be understood that any of the embodiments described in this application and the technical features included therein can be combined with each other.

[0032] The present utility model will be further described in detail below in conjunction with the drawings and specific embodiments.

[0033] As Figure 1 and Figure 2 shown, a chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids includes a pretreatment device 1, a pressure pump 2, a heating device 3, a constant-temperature test device 4, and a post-treatment device 5 arranged in series. The devices of this system are generally arranged in a longitudinal direction. This strip layout can save floor space and multiple systems can be arranged side by side to improve the test efficiency.

[0034] As Figure 1-3As shown, the pretreatment device 1 is used to preheat the test fluid to below 95°C to obtain preheated fluid, and has a first liquid inlet 101a for receiving the test fluid and a first liquid outlet 101b for discharging the preheated fluid. The pretreatment device 1 has a pretreatment box body 101. The side of the pretreatment box body 101 has a chemical dosing port 101c for adding acetic acid and sodium hypochlorite and a cleaning port 101d for discharging the test fluid. The top of the pretreatment box body 101 is configured with a water replenishing tank 102 for replenishing the test fluid, and its side is configured with a detection and control box 103. Among them, the pretreatment box body 101 is of a square structure, and the volume of the water replenishing tank 102 is approximately the same as that of the pretreatment box body 101. When the test fluid in the pretreatment box body 101 needs to be replaced or replenished, first, the test fluid in the pretreatment box body 101 is emptied through the cleaning port 101d, and then the same volume of test fluid is replenished at one time through the water replenishing tank 102 to ensure the convenience and efficiency of the operation. Among them, the function of the detection and control box 103 is to detect the key parameters of the test fluid in real time, such as pH value, ORP (oxidation-reduction potential), and residual chlorine value, etc. When it is detected that the parameters deviate from the set range, the detection and control box 103 will send a signal command to the external chemical dosing tank, automatically triggering the chemical dosing process. According to the instruction of the detection and control box 103, the chemicals (such as acetic acid, sodium hypochlorite, etc.) in the chemical dosing tank are pumped into the interior of the pretreatment box body 101 through the chemical dosing port 101c to realize the automatic conditioning of the liquid, so as to maintain the stability and suitability of parameters such as pH, ORP, and residual chlorine value in the test fluid. Among them, a heating element is configured inside the pretreatment box body 101, and the heating element can be an electric heating tube or other devices that realize the heating function. Both the pretreatment box body 101 and the water replenishing tank 102 are normal pressure box bodies, and can preheat the test fluid at room temperature to below 95°C to reach a constant temperature.

[0035] As Figure 1 and Figure 2 shown, the pressure pump 2 is used to receive the preheated fluid and boost its pressure to obtain pressurized preheated fluid. Among them, the pressure pump 2 is a centrifugal pump. The centrifugal pump uses the rotation of the impeller to generate centrifugal force. When the preheated fluid is sucked into the pump body, with the rapid rotation of the impeller, the preheated fluid is thrown towards the outer edge of the pump shell, and its speed increases while the pressure also increases accordingly. The kinetic energy of the liquid is converted into pressure energy, thus realizing the pressure boosting effect. The inlet end of the centrifugal pump is connected to the first liquid outlet 101b through a pipeline, and the outlet end of the centrifugal pump is connected to the second liquid inlet 301a of the temperature-rising cavity 301 through a pipeline.

[0036] As Figure 1 、 2As shown in FIGS. 4 and 5, the heating device 3 is used to reheat the pressurized preheated fluid to above 100° C. to obtain a high-temperature internal pressure fluid. The heating device 3 includes a heating cavity 301 and a first spiral coil 302 disposed inside the heating cavity 301. The side of the heating cavity 301 has a second liquid inlet 301a for receiving the pressurized preheated fluid and a second liquid outlet 301b for discharging the high-temperature internal pressure fluid. The second liquid outlet 301b is located above the second liquid inlet 301a. The two ends of the first spiral coil 302 are respectively fluidly connected to the second liquid inlet 301a and the second liquid outlet 301b. Both ends of the heating cavity 301 respectively have a heat medium inlet 301c and a heat medium outlet 301d for circulating the heating medium. The heating medium is steam, hot oil or other heat exchange media. Among them, the preferred temperature of the high-temperature internal pressure fluid is 105° C. and / or 115° C. Among them, the first spiral coil 302 is a spiral structure, which not only increases the contact area between the pressurized preheated fluid and the heating medium, but also increases the residence time of the pressurized preheated fluid in the heating cavity 301, so that the pressurized preheated fluid is heated and converted into a high-temperature internal pressure fluid, improving the heating efficiency.

[0037] As Figure 1 , 2As shown in FIGS. 3 and 4, a plurality of first conveying pipelines 6 are arranged between the heating device 3 and the constant temperature test device 4. The second liquid outlet 301b is communicated with the third liquid inlet 401a through the first conveying pipeline 6. A pressure regulating valve 601, a pressure gauge 602 and a shut-off valve 603 are sequentially arranged on the first conveying pipeline 6. The pressure regulating valve 601 accurately and automatically regulates the pressure of the first conveying pipeline 6 according to the pressure required for the test. The pressure gauge 602 is used to measure the pressure of the first conveying pipeline 6. The shut-off valve 603 is used to close the fluid of the first conveying pipeline 6. Among them, the pressure pump 2, the heating device 3 and the pressure regulating valve 601 are fixed by a support device 8. The support device 8 includes a support frame 801. A partition plate 801b and a bottom plate 801a are arranged up and down in the support frame 801 to divide the space in the support frame 801 into two placement spaces. The placement space is used to fix the pressure regulating valve 601. Support feet 801c and pulleys 801d are arranged at the four corners of the bottom of the support frame 801. The support frame 801 can be fixed or moved through the support feet 801c and the pulleys 801d. An extension plate 802 is arranged on one side of the bottom plate 801a. The bottom of the extension plate 802 has a support column 803. The pressure pump 2 and the heating device 3 are fixed on the extension plate 802. In this embodiment, the number of the first conveying pipelines 6 is six. The pressure regulating valve 601, the pressure gauge 602 and the shut-off valve 603 are arranged on all the six first conveying pipelines 6. Each first conveying pipeline 6 includes a front branch pipeline and a rear branch pipeline. Six front branch pipelines are branched from the second liquid outlet 301b of the heating cavity 301 to the inlet ends of six pressure regulating valves 601. Among them, three pressure regulating valves 601 are fixed on the partition plate 801b, and three pressure regulating valves 601 are fixed on the bottom plate 801a. The outlet ends of the six pressure regulating valves 601 are connected to different third liquid inlets 401a through six rear branch pipelines. The rear branch pipelines are provided with pressure gauges 602 and shut-off valves 603. Of course, the number of the first conveying pipelines 6 can also be eight, ten, etc., and can be increased according to needs. More preferably, the number of the first conveying pipelines 6 is twelve.

[0038] As Figure 1 , 2As shown in FIGS. 6 and 7, the constant temperature test device 4 has a test chamber 401. On both sides of the test chamber 401, a plurality of third liquid inlets 401a for receiving high-temperature internal pressure fluid and a plurality of third liquid outlets 401b for discharging high-temperature internal pressure fluid are respectively arranged. Inside it, a plurality of test pipe fittings 402 are arranged side by side at a certain interval along the vertical direction. Both ends of the test pipe fittings 402 are respectively connected to the third liquid inlets 401a and the third liquid outlets 401b. One side or both sides of the test chamber 401 are open and a chamber door 403 is detachably arranged, which is convenient for taking and placing the test pipe fittings 402. In this embodiment, one side of the test chamber 401 is open and a chamber door 403 is arranged. In other embodiments, the front and rear sides of the test chamber 401 can be open and both are provided with chamber doors 403. The bottom of the test chamber 401 is provided with a base 404, and its side parts are respectively provided with a gas inlet 401d for receiving constant temperature gas and a gas outlet 401c for discharging constant temperature gas. Among them, a thermostat (not shown in the figure) is arranged outside the test chamber 401, and the thermostat is respectively connected to the gas inlet 401d and the gas outlet 401c through pipelines, so that the constant temperature gas circulates in the test chamber 401 to maintain the temperature inside the test chamber 401. Specifically, the thermostat generates constant temperature gas and enters from the lower gas inlet 401d of the test chamber 401 through the pipeline. The constant temperature gas flows upward from the bottom of the test chamber 401 through the plurality of test pipe fittings 402 and is discharged from the gas outlet 401c, so that the test pipe fittings 402 are in a constant temperature and normal pressure environment. The plurality of test pipe fittings 402 in the test chamber 401 are arranged in parallel in the horizontal direction and are fluidly connected to be able to test a plurality of test pipes simultaneously. The test pipe fitting 402 includes a pair of fixing parts 402a, a pair of clamping parts 402b and a pipe body 402c. The pair of fixing parts 402a are respectively arranged on the third liquid inlets 401a and the third liquid outlets 401b. The pair of clamping parts 402b are respectively fixed at the ends of the fixing parts 402a. Both ends of the pipe body 402c are detachably arranged on the clamping parts 402b. The pipe body 402c is a plastic pipe to be tested. In this embodiment, the number of test pipe fittings 402 is twelve, which are vertically arranged into two columns of test pipe fitting groups in the test chamber 401, and the number of each column of test pipe fitting groups is six. In the horizontal direction, every two test pipe fittings 402 are arranged in parallel. Each of the six rear branch pipelines divides into two sub-pipelines and is respectively connected to two parallel arranged test pipe fittings 402 through two third liquid inlets 401a, realizing the parallel operation and fluid connection of the two test pipe fittings 402, and the fluid of each layer of test pipe fittings 402 is independent of each other. Of course, the number of test pipe fittings 402 can be vertically and horizontally arranged according to actual needs. For example, three columns or four columns of test pipe fitting groups are vertically arranged, that is, three or four test pipe fittings are horizontally arranged, so as to improve the test efficiency and accuracy.

[0039] As Figure 1 、2 As shown in FIGS. 7 and 8, the post-treatment device 5 is used to cool the high-temperature internal pressure fluid from the constant-temperature test device 4 to obtain a cooled fluid, and has a plurality of fourth liquid inlets 502a for receiving the high-temperature internal pressure fluid and a fourth liquid outlet 501a for discharging the cooled fluid. A cooler 503 is disposed inside it. The cooled fluid is circulated through a pipeline to the pretreatment device 1. The post-treatment device 5 has a return water tank body 501 and a delivery cylinder 502 disposed on the top of the return water tank body 501. The return water tank body 501 is an atmospheric pressure water tank. The plurality of fourth liquid inlets 502a are arranged at certain intervals along the vertical direction of the delivery cylinder 502. The fourth liquid outlet 501a is disposed on the side of the return water tank body 501. A plurality of second delivery pipelines 7 are disposed between the constant-temperature test device 4 and the post-treatment device 5. The third liquid outlet 401b is communicated with the fourth liquid inlet 502a through the second delivery pipeline 7. A check valve 701 and a flow control valve 702 are sequentially disposed on the second delivery pipeline 7. The check valve 701 is used to prevent the high-temperature internal pressure fluid from flowing back into the constant-temperature test device 4. The flow control valve 702 is used to adjust the size of the fluid to ensure that the fluid in the second delivery pipeline 7 meets the test requirements. The cooler 503 is located inside the delivery cylinder 502. The fourth liquid inlet 502a is correspondingly disposed with the cooler 503. The cooler 503 has a second spiral coil 503a. The cold medium inlet 503a1 of the second spiral coil 503a is fixed at the top of the delivery cylinder 502, and the cold medium outlet 503a2 is fixed at the side of the return water tank body 501 for connecting a cooling medium to reduce the temperature of the high-temperature internal pressure fluid. The delivery cylinder 502 is a vertical hollow cylindrical structure. When the high-temperature internal pressure fluid enters the delivery cylinder 502 through the plurality of second delivery pipelines 7, the high-temperature internal pressure fluid will be vaporized. After flowing through the cooler 503, the water vapor is converted into a cooled fluid with a temperature less than 95°C. The cooled fluid converges into the return water tank body 501 under the action of gravity, thereby ensuring that the liquid after the test can smoothly flow back to the pretreatment device 1 through the circulation water pipe 9. It should be noted that a circulation pump is disposed on the circulation water pipe 9 to ensure that the liquid can smoothly flow back to the pretreatment device 1. In this embodiment, the number of the second delivery pipelines 7 is six, and every two parallel test pipe fittings 402 are converged into a corresponding second delivery pipeline 7 through a pipeline.

[0040] In an embodiment not shown, both the first delivery pipeline 6 and the second delivery pipeline 7 are provided with heat insulation layers.

[0041] In an embodiment not shown, a control system is further configured. The control system is communicatively connected to the pretreatment device 1, the pressure pump 2, the temperature-raising device 3, the constant-temperature test device 4, and the post-treatment device 5 respectively. The specific control process is as follows: Initialization and parameter setting: The control system first initializes and sets various parameters required for the test, including the pretreatment temperature, the pressurization pressure, the temperature-raising temperature, the constant-temperature temperature, the temperature-lowering temperature, etc. Pretreatment stage control: The control system starts the pretreatment device 1, controls the makeup water tank 102 to supplement the test fluid into the pretreatment tank 101, and automatically adds an appropriate amount of acetic acid and sodium hypochlorite through the chemical addition port 101c. Monitor the temperature and liquid state in the pretreatment tank 101 to ensure that the test fluid is preheated to below 95°C, and then discharge it to the pressure pump 2 through the first liquid outlet 101b. Pressurization and temperature-raising stage control: The control system starts the pressure pump 2 to boost the preheated fluid to the set pressure to form a pressurized and preheated fluid. Subsequently, control the circulation of the heating medium in the temperature-raising device 3, and heat the pressurized and preheated fluid to above 100°C through the first spiral coil 302 to form a high-temperature internal pressure fluid. During this process, the control system uses the pressure regulating valve 601, the pressure gauge 602, and the shut-off valve 603 on the first pipeline 6 to monitor and adjust the pressure and flow rate in the pipeline in real time to ensure that the high-temperature internal pressure fluid is transported to the constant-temperature test device 4. Constant-temperature test stage control: The control system controls the thermostat to maintain the temperature in the test tank 401 constant, ensure that the test pipe fitting 402 undergoes a chlorine oxidation resistance test at the set temperature, and monitor the temperature in the test tank 401. Post-treatment and circulation control: The control system starts the post-treatment device 5, transports the high-temperature internal pressure fluid in the constant-temperature test device 4 to the post-treatment device 5 through the second pipeline 7 for temperature reduction. The control system uses the one-way valve 701 to prevent liquid backflow and adjusts the flow rate through the flow control valve 702. The second spiral coil 503a in the cooler 503 is connected to the cooling medium to cool the high-temperature internal pressure fluid, ensure that there is no water vapor in the delivery cylinder 502, and the water temperature in the return water tank 501 is lower than 95°C to form a temperature-reduced fluid. Real-time monitoring and feedback: The control system monitors the operating states of each device and various parameters of the test fluid (such as temperature, pressure, pH value, ORP, residual chlorine content, etc.) in real time during the entire test process. According to the monitoring results, the control system automatically adjusts relevant parameters or issues an alarm to ensure the accuracy and safety of the test process. Test end and data processing: After the test is completed, the control system automatically stops the operation of each device, collects and organizes the test data, analyzes and processes the test data, generates a test report, and provides a basis for subsequent evaluation and improvement.

[0042] Among them, the pretreatment box 101 and the makeup water tank 102 are controlled by a control system to realize regular automatic water change of the test fluid in the pretreatment box 101, avoiding excessive impurity content in the test fluid in the pretreatment box 101. The control system controls the collaborative work of the chemical dosing tank and the detection and control box 103. By inputting specific test parameter requirements through the control system, the system automatically triggers the chemical dosing process and real-time monitors the pH value, oxidation-reduction potential (ORP), and residual chlorine content of the test fluid. The pressure regulating valve 601 on the first delivery pipeline 6 independently and automatically regulates the pressure of the pipeline; at the same time, the control system automatically detects the pressure of each pipeline in real time through the pressure gauge 602 and feeds back the signal to the pressure regulating valve 601 to achieve precise pressure control of each pipeline and ensure the accuracy of the test pressure.

[0043] In an embodiment not shown, a specimen rupture detection device is configured on each first delivery pipeline 6, which can instantaneously monitor the integrity of the test tube. Once a rupture of the test tube is detected, the shut-off valve 603 on this pipeline will immediately respond and automatically close to block the further outflow of the test fluid, effectively preventing the leakage of the test fluid. Through the collaborative work of the pressure regulating valve 601 and the shut-off valve 603, when the test tube of a certain pipeline breaks and fails, the pressure regulating valve 601 can adjust the pressure of other pipelines to ensure that other test tubes continue to maintain within the preset test pressure range, thus ensuring the coherence of the entire test process and the reliability of the data. Among them, the specimen rupture detection device can be a pressure sensor or a water leakage detector, etc. In addition, the pretreatment box 101 and the makeup water tank 102 are both equipped with water shortage protection and anti-dry burning functions, effectively avoiding potential safety hazards caused by too low water level or dry burning of the heating element. At the same time, the overall system also incorporates multiple safety mechanisms such as under-voltage protection, leakage detection, and water leakage protection. Once any one of these protection conditions is triggered, the system will immediately start the automatic shutdown procedure to cut off all power sources and fluid supplies that may cause danger, ensuring the safety of the operator and the equipment.

[0044] Among them, directly pressurizing and heating the test fluid to above 100°C in the pretreatment device 1 is theoretically feasible, but in actual operation, it faces many infeasibilities and safety hazards. Specifically, there are the following key problems: (1) Recycling and pressurization: The test fluid needs to be recycled. If it is directly pressurized in the pretreatment device 1, the entire circulation pipeline must bear high pressure, which not only increases the complexity and cost of the system, but also may lead to poor return water or ineffective implementation. (2) Safety risks and pressure vessels: The pretreatment box 101 has a large volume. If the water temperature needs to be raised to 100°C or even higher, a great deal of pressure needs to be applied. During this process, if gas is mixed into the pretreatment box 101, there is a serious safety risk of steam explosion, turning the pretreatment box 101 into a pressure vessel and posing a threat to the test personnel. If the gas is removed, the pretreatment box 101 needs to be continuously kept full of water, which is almost impossible to achieve in actual operation because it is difficult to precisely match the speed of the pressure pump 2 and the circulating return water. (3) Pressure dynamic balance: Since the test fluid is continuously pumped away by the pressure pump 2, it is difficult to maintain the pressure of the pretreatment box 101 stable. At the same time, the return water speed is affected by various factors (such as the flow rate change caused by the rupture of the test pipe fitting 402), and it is impossible to achieve precise synchronization with the pumping speed, which may cause negative pressure in the pretreatment box 101 and then lead to safety problems. (4) Pressurization method: Since gas pressurization has safety hazards, and directly pressurizing the pretreatment box 101 through the pressure pump 2 faces the above-mentioned problem of dynamic balance control, the technical difficulty is high and the cost is expensive.

[0045] Therefore, by configuring the heating device 3, the separation of temperature and pressure control can be achieved. In the pretreatment device 1, the test fluid is preheated to below 95°C. This temperature range is not only easy to control but also can effectively avoid the vaporization of the liquid. Subsequently, it enters the pressurization stage, and the preheated liquid is sent to the pressure pump 2 for pressurization. Since the liquid temperature is moderate at this time, the pressurization process is safe and controllable, reducing the unstable factors and additional pressure fluctuations caused by liquid vaporization, thereby improving the stability of the system. The pressurized liquid is introduced into the independent heating device 3, and the liquid temperature is raised to above 100°C through an efficient heating medium (such as hot oil, heating tape, etc.) to obtain a high-temperature internal pressure fluid. This process is independently carried out in the heating device 3, ensuring precise control of the heating process and effectively avoiding the safety risks that may be caused by directly pressurizing and heating in the pretreatment device 1. Then, the high-temperature internal pressure fluid is cooled by the cooler 503 to achieve recycling or subsequent treatment.

[0046] The test method of the present utility model is as follows:

[0047] S1. Preparation stage: Install the plastic pipe sample to be tested into the test pipe fitting 402 of the constant temperature test device 4. Add the test fluid into the pretreatment box 101 of the pretreatment device 1, and add acetic acid and sodium hypochlorite at a predetermined ratio through the chemical dosing port 101c.

[0048] S2. Pretreatment stage: Start the pretreatment device 1, preheat the test fluid to below 95°C to obtain the preheated fluid. Monitor the liquid temperature and chemical composition through the detection control box 103. After the pretreatment is completed, the preheated fluid is discharged from the first liquid outlet 101b of the pretreatment device 1 to the pressure pump 2.

[0049] S3. Pressurization and reheating stage: The pressure pump 2 receives the preheated fluid and boosts its pressure to the set pressure. Subsequently, the pressurized and preheated fluid enters the temperature rising device 3 and is reheated to above 100°C through the first spiral coil 302 inside the temperature rising cavity 301 to obtain the high-temperature internal pressure fluid. The heating medium circulates through the heat medium inlet 301c and the heat medium outlet 301d to maintain the temperature of the temperature rising cavity 301.

[0050] S4. Constant temperature test stage: The high-temperature internal pressure fluid enters the test box 401 of the constant temperature test device 4 through the first pipeline 6 and flows through the plastic pipes inside each test pipe fitting 402 respectively. Maintain the temperature of the test box 401 within the set range through the thermostat 404, and keep the box door 403 closed. During the test process, regularly check and record the pressure and temperature changes of each test pipe fitting 402.

[0051] S5. Post-treatment and circulation stage: The high-temperature internal pressure fluid enters the return water tank 501 of the post-treatment device 5 through the second pipeline 7. Inside the return water tank 501, the high-temperature internal pressure fluid is cooled through the cooler 503 to lower the liquid temperature to less than 100°C to obtain the cooled fluid. The cooled liquid is discharged through the fourth liquid outlet 501a and circulated to the pretreatment device 1 through the circulation water pipe 9 to achieve the recycling of the liquid.

[0052] S6. Data recording and analysis: Record the changes of each key parameter during the whole test process, including the pretreatment temperature, pressurization pressure, temperature rising temperature, constant temperature time, temperature after cooling, etc. Analyze the long-term service life of the plastic pipe in the high-temperature chlorine oxidation environment according to the test results, and evaluate whether it meets the relevant standards or design requirements.

[0053] Generally speaking, the present utility model is a chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids, including a pretreatment device, a pressure pump, a heating device, a constant-temperature test device, and a post-treatment device arranged in series. This system can ensure that the aqueous solution entering the plastic pipe breaks through the 100°C limit while remaining in a liquid state, reaches and meets the 115°C aqueous solution high-temperature test conditions specified by industry standards, and realizes automatic water replenishment and real-time monitoring and control of the temperature, pressure, pH, ORP, and residual chlorine of the test fluid, achieving unmanned intelligent operation. The present utility model realizes the recycling of heating and cooling of the test fluid during the test by configuring a heating device and a cooler. The heating device can heat the test fluid to above 100°C, enabling the test tube to be subjected to high-temperature liquid and testing its chlorine oxidation resistance performance, while the cooler cools the test fluid to prevent the vaporization of high-pressure liquid due to pressure drop, ensuring that the aqueous solution can smoothly flow back to the pretreatment device through the circulation water pipe. This not only reduces energy consumption but also reduces the demand for water resources, reflecting the environmental protection concept of energy conservation and emission reduction. At the same time, the recycling of the test fluid also reduces wastewater discharge, which is beneficial to environmental protection. The present utility model ensures the precise control of the temperature of the test fluid through the coordinated operation of the pretreatment device and the control system. The test fluid can be preheated in the water replenishment tank to keep its temperature consistent with that of the test fluid in the pretreatment box, avoiding the water temperature fluctuation caused by water replacement, thereby improving the accuracy and reliability of the test. The present utility model realizes the real-time automatic detection and adjustment of the pH, ORP, and residual chlorine content of the test fluid through the combined use of an external chemical dosing tank and a detection control box, combined with the automatic control function of the control system. This not only reduces the burden of manual operation but also improves the detection accuracy and efficiency, ensuring the accuracy and reliability of the test results.

[0054] The above embodiments are the preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present utility model shall be equivalent replacement methods and are all included in the protection scope of the present utility model.

Claims

1. A chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids, characterized in that, Comprising: A pretreatment device, which is used to preheat the test fluid to below 95°C to obtain a preheated fluid, and has a first liquid inlet for receiving the test fluid and a first liquid outlet for discharging the preheated fluid; A pressure pump, which is used to receive the preheated fluid and boost its pressure to obtain a pressurized preheated fluid; A heating-up device, which is used to reheat the pressurized preheated fluid to above 100°C to obtain a high-temperature internal pressure fluid. The heating-up device includes a heating-up cavity and a first spiral coil arranged inside the heating-up cavity. The side of the heating-up cavity has a second liquid inlet for receiving the pressurized preheated fluid and a second liquid outlet for discharging the high-temperature internal pressure fluid. The two ends of the first spiral coil are respectively fluid-connected to the second liquid inlet and the second liquid outlet. The two ends of the heating-up cavity respectively have a heat medium inlet and a heat medium outlet for circulating the heating medium; A constant-temperature test device, which has a test box body. On both sides of the test box body, there are respectively configured a plurality of third liquid inlets for receiving the high-temperature internal pressure fluid and a plurality of third liquid outlets for discharging the high-temperature internal pressure fluid. Inside it, a plurality of test pipe fittings are arranged side by side at a certain interval along the vertical direction. The two ends of the test pipe fittings are respectively connected to the third liquid inlets and the third liquid outlets; A post-treatment device, which is used to cool down the high-temperature internal pressure fluid from the constant-temperature test device to obtain a cooled fluid, and has a plurality of fourth liquid inlets for receiving the high-temperature internal pressure fluid and a fourth liquid outlet for discharging the cooled fluid. A cooler is configured inside it. Wherein, the cooled fluid is circulated to the pretreatment device through a pipeline.

2. The chlorine oxidation resistance system for testing the resistance of plastic pipes to high-temperature internal pressure fluid according to claim 1, characterized in that, The pretreatment device has a pretreatment box body. The side of the pretreatment box body has a chemical addition port for adding acetic acid and sodium hypochlorite and a cleaning port for discharging the test fluid. The top of the pretreatment box body is configured with a water replenishment tank for supplementing the test fluid and its side is configured with a detection control box.

3. A chlorine oxidation resistance system for testing the resistance of plastic pipes to high-temperature internal pressure fluids according to claim 1, characterized in that, A plurality of first conveying pipelines are configured between the heating-up device and the constant-temperature test device. The second liquid outlet is communicated with the third liquid inlet through the first conveying pipeline. A pressure regulating valve, a pressure gauge and a shut-off valve are sequentially configured on the first conveying pipeline.

4. A chlorine oxidation resistance system for testing the resistance of plastic pipes to high-temperature internal pressure fluids according to claim 1, characterized in that, One side or both sides of the test box body are open and are detachably configured with a box door. The bottom of the test box body is configured with a base, and its sides are respectively configured with a gas inlet for receiving a constant-temperature gas and a gas outlet for discharging the constant-temperature gas.

5. A chlorine oxidation resistance system for testing the resistance of plastic pipes to high-temperature internal pressure fluids according to claim 1, characterized in that, The plurality of test pipe fittings in the test box body are arranged in parallel in the horizontal direction and are fluid-connected.

6. A chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids according to claim 1, characterized in that, The test pipe fitting includes a pair of fixing parts, a pair of clamping parts and a pipe body. The pair of fixing parts are respectively arranged on the third liquid inlet and the third liquid outlet. The pair of clamping parts are respectively fixed at the ends of the fixing parts. The two ends of the pipe body are detachably configured on the clamping parts.

7. A chlorine oxidation resistance system for testing the resistance of plastic pipes to high-temperature internal pressure fluids according to claim 1, characterized in that, The post-treatment device has a water return tank body and a conveying cylinder arranged at the top of the water return tank body. The plurality of fourth liquid inlets are arranged at a certain interval along the vertical direction of the conveying cylinder. The fourth liquid outlet is arranged at the side of the water return tank body. A plurality of second conveying pipelines are configured between the constant temperature test device and the post-treatment device. The third liquid outlet is communicated with the fourth liquid inlet through the second conveying pipeline. A one-way valve and a flow regulating valve are sequentially arranged on the second conveying pipeline.

8. A chlorine oxidation resistance system for testing plastic pipes in high-temperature internal pressure fluids according to claim 7, characterized in that, The cooler is located in the conveying cylinder and has a second spiral coil pipe. The cold medium inlet of the second spiral coil pipe is fixed at the top of the conveying cylinder, and the cold medium outlet is fixed at the side of the water return tank body, for connecting a cooling medium to reduce the temperature of the high-temperature internal pressure fluid.

9. A chlorine oxidation resistance system for testing a plastic pipe in a high-temperature internal pressure fluid according to claim 1, characterized in that, The temperature of the high-temperature internal pressure fluid is 105 °C or 115 °C, and the temperature of the cooling fluid is less than 100 °C.

10. A chlorine oxidation resistance system for testing a plastic pipe in a high-temperature internal pressure fluid according to claim 1, characterized in that, A control system is also configured. The control system is respectively communicatively connected with the pretreatment device, the pressure pump, the heating device, the constant temperature test device and the post-treatment device.

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