A heat exchange tube working condition corrosion resistance examination test device

Abstract

The present application belongs to the technical field of high-temperature corrosion and specifically relates to a corrosion resistance examination test device for heat exchange pipes under working conditions, which comprises a steam generation cabin, two sealing flanges arranged at two ends of the steam generation cabin, a heating pipe or a heating jacket arranged outside, a temperature feedback device arranged inside and a heat exchange pipe, can simulate different working conditions in a laboratory, carry out high-temperature corrosion influence tests of different factors (microorganisms, water quality, temperature, materials, etc.) on the heat exchange pipe, evaluate the corrosion resistance of the heat exchange pipe, study the corrosion behavior of the pipe system material under high-temperature steam, and have important significance for material selection and research and development of the heat exchange pipe; the device has a simple structure, is easy to implement and small in size, can be customized for different sizes of pipes, realizes the working conditions of saturated steam and superheated steam in the laboratory, carries out high-temperature steam related tests, and especially for the heat exchange pipe, the test working condition of steam on the outer wall of the pipeline and cooling water on the inner wall of the pipeline can be realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high-temperature corrosion and particularly relates to a heat exchange pipe working condition corrosion resistance examination test device. BACKGROUND

[0002] A condenser is a kind of heat exchanger and is a component of a refrigeration system, which can convert gas or steam into liquid. Cooling water is passed through the pipes, and high-temperature steam is on the outer wall of the pipes. The high-temperature steam is cooled to release heat and becomes liquid water. Condensers are widely used in power plants and on ships, for example, ship power devices, air compressor systems, hydraulic rudder systems, auxiliary boiler devices, air conditioning and refrigeration devices, water making devices, and the like. The condensers used in coastal nuclear power plants and on ships are basically cooled by seawater. Since seawater has strong corrosive properties, the heat exchange pipes in the condensers are prone to corrosion and failure after a period of use, and even damage, which may cause serious accidents.

[0003] Since the late 1930s, copper-nickel alloy has been developed in the United Kingdom, which is widely used to manufacture heat exchange pipes of condensers due to its excellent corrosion resistance and heat conductivity. However, corrosion and leakage accidents of copper-nickel alloy heat exchange pipes still occur. The heat exchange pipes used in power plants are also made of copper-nickel alloy, and some pipe corrosion and perforation failures have also occurred. Due to the frequent leakage of copper-nickel alloy heat exchange pipes, some power plants have replaced them with titanium pipes. Although titanium pipes have better corrosion resistance than copper-nickel alloy, their heat transfer performance, resistance to fouling, and price advantages are significantly weaker than those of copper-nickel alloy. Therefore, copper-nickel alloy heat exchange pipes are still mainly used in the field of ships.

[0004] As early as the 1980s, scholars conducted research and analysis on the early corrosion and leakage accidents of B30 copper-nickel alloy used in ships. The research showed that the early leakage of the pipes was caused by the mutual superposition and intensification of local defects of the pipe material, carbon film, and deposition corrosion factors. With the improvement of processing capacity and quality control, the local defects of the pipe material and the carbon film have been effectively controlled, but corrosion and leakage of copper-nickel alloy pipes still occur. According to relevant research, the causes of corrosion include the following: deposition on the surface of the alloy, microorganisms, marine organism blockage, and hard particle erosion.

[0005] The corrosion resistance test equipment in the prior art has single function and cannot simulate actual working conditions and has no reference value.For example, the intelligent equipment for testing corrosion resistance of metal material disclosed in Chinese patent 202221407515.X comprises a heating box body, a temperature feedback device, an electrochemical test device, a steam filling device, a solution steam storage box body and a controllable temperature humidifier, the solution steam storage box body is arranged in the interior of the heating box body, the temperature feedback device and the electrochemical test device are connected in the solution steam storage box body, one end of the steam filling device is arranged in the solution steam storage box body and is arranged at a certain distance from the sample placed in the electrochemical test device, and the other end of the steam filling device is connected with the outlet of the controllable temperature humidifier; the intelligent equipment can carry out electrochemical test in a high-temperature, high-humidity and high-salt salt spray environment, but cannot simulate working conditions of heat exchange pipes, such as deposition, microbial and marine organism blockage and hard particle scouring.

[0006] In view of the special working conditions and frequent leakage problems of heat exchange pipes, it is urgent to develop and design a corrosion resistance test device under the working conditions of heat exchange pipes to provide convenient test conditions for heat exchange pipes, provide an evaluation device for development of new material heat exchange pipes, and study the corrosion behavior of pipe system materials under high-temperature steam. SUMMARY

[0007] The purpose of the present application is to overcome the shortcomings of the prior art, and to develop and design a corrosion resistance test device under the working conditions of heat exchange pipes to carry out high-temperature corrosion test of heat exchange pipes in the laboratory and evaluate the corrosion resistance of heat exchange pipes.

[0008] In order to achieve the above-mentioned purpose, the main structure of the corrosion resistance test device under the working conditions of heat exchange pipes comprises a steam generating cabin, two sealing flanges arranged at both ends thereof, an external heating pipe or heating sleeve, an internal temperature feedback device and a heat exchange pipe; the two sealing flanges are connected through locking bolts and locking nuts, the temperature feedback device is connected with the heating pipe or heating sleeve through a heating control device by penetrating the inside sealing flange at one end, the heat exchange pipe is connected with external cooling water by penetrating the sealing flanges at both ends, and the inside sealing flange is connected with the temperature feedback device and the heat exchange pipe through pressure maintaining studs and pressure maintaining nuts.

[0009] The material of the steam generating cabin comprises titanium and stainless steel, titanium is used when corrosive medium is contained, and stainless steel or titanium is used when the solution with chloride ion concentration <100 ppm is contained; the outer sealing flange has a right-angle U-shaped structure; the heating pipe cooperates with the temperature feedback device and the heating control device to heat the steam generating cabin to make the temperature thereof reach a set value; the number of the heat exchange pipes is an integer greater than or equal to 1; the pressure maintaining stud has a hollow structure and is made of the same material as the steam generating cabin and is connected with the steam generating cabin by welding or is integrally processed and formed.

[0010] The principle of the corrosion resistance test device under the working condition of the heat exchange pipe involved in the application is:

[0011] The steam generation cabin is heated by a heating pipe or a heating jacket, and the solution in the steam generation cabin is heated to become steam in a limited space, forming a high-temperature steam working condition. Cooling water is passed through the heat exchange pipe, and the corrosion resistance of the heat exchange pipe is tested under the high-temperature steam working condition. When the temperature in the steam generation cabin is lower than the set value, the temperature feedback device transmits a signal to the heating control device, and the heating control device controls the heating pipe to start heating. When the temperature in the steam generation cabin reaches the set value, the temperature feedback device transmits a signal to the heating control device, and the heating control device controls the heating pipe to stop heating.

[0012] When the corrosion influence of simulated sediments or marine organisms on the heat exchange pipe is simulated, the sediments or marine organisms are pre-prepared in the heat exchange pipe.

[0013] When the corrosion influence of simulated microorganisms or hard particles on the heat exchange pipe is simulated, the test is performed using cooling water rich in microorganisms or cooling water rich in hard particles.

[0014] When the corrosion influence of temperature difference on the heat exchange pipe is simulated, the test is performed by controlling the temperature of the cooling water and the temperature of the steam.

[0015] Compared with the prior art, the application can simulate different working conditions in the laboratory, carry out high-temperature corrosion influence tests of different factors (microorganisms, water quality, temperature, materials, etc.) on the heat exchange pipe, evaluate the corrosion resistance of the heat exchange pipe, and research the corrosion behavior of the pipe system material under high-temperature steam, which has important significance for the selection and research and development of the heat exchange pipe. The structure is simple, easy to implement, small in size, and can be customized for different sizes of pipe materials. The working conditions of saturated steam and superheated steam can be realized in the laboratory to carry out high-temperature steam related tests, especially for the heat exchange pipe, the working conditions of steam on the outer wall of the pipeline and cooling water in the inner wall of the pipeline can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of the main structure of the application.

[0017] Figure 2 The figure is a schematic diagram of the local structure of the application. DETAILED DESCRIPTION

[0018] The application will be further described below through implementation examples and in combination with the drawings.

[0019] Example 1

[0020] The main body structure of the corrosion resistance test device under the working condition of the heat exchange pipe in the embodiment includes a steam generating cabin 1, an inner sealing flange 2, an outer sealing flange 3, locking bolts 4, locking nuts 5, a heating pipe 6, a temperature feedback device 7, heat exchange pipes 8, a heating control device 9, a pressure maintaining stud 10, a pressure maintaining nut 11 and a high-temperature-resistant sealing ring 12. The steam generating cabin 1 in a cylindrical structure is provided with the inner sealing flange 2 and the outer sealing flange 3 in a right-angle U-shaped structure at both ends. The inner sealing flanges 2 and the outer sealing flanges 3 at both ends are connected through the locking bolts 4 and the locking nuts 5 to seal the steam generating cabin 1. The steam generating cabin 1 is provided with the heating pipe 6 outside and the temperature feedback device 7 and the two heat exchange pipes 8 inside. The temperature feedback device 7 passes through the inner sealing flange 2 and the outer sealing flange 3 at one end and is connected with the heating pipe 6 through the heating control device 9. The heat exchange pipes 8 pass through the inner sealing flanges 2 and the outer sealing flanges 3 at both ends and are connected with the external cooling water. The inner sealing flange 2 is connected with the temperature feedback device 7 and the heat exchange pipes 8 through the pressure maintaining stud 10 and the pressure maintaining nut 11. The high-temperature-resistant sealing ring 12 is arranged between the steam generating cabin 1 and the inner sealing flange 2 and between the temperature feedback device 7 and the heat exchange pipes 8 and the pressure maintaining stud 10. The pressure maintaining stud 10, the pressure maintaining nut 11 and the high-temperature-resistant sealing ring 12 are arranged when the temperature feedback device 7 and the heat exchange pipes 8 pass through the inner sealing flange 2.

[0021] The steam generating cabin 1 in the embodiment is in a cylindrical structure and is sealed at both ends through the inner sealing flange 2 and the outer sealing flange 3. The outer sealing flange 3 presses the inner sealing flange 2 and the pressure maintaining nut 11 to guarantee the pressure in the steam generating cabin 1. The heating temperature range of the heating pipe 6 is 25-450℃, which can meet the test conditions of saturated steam and superheated steam. The main body structure of the heating control device 9 includes a display screen, a power indicator, a running indicator and a switch. The display screen is used to display the temperature in the steam generating cabin 1 in real time. The pressure maintaining nut 11 is used to press the high-temperature-resistant sealing ring 12 to prevent the steam generating cabin 1 from leaking. The material of the high-temperature-resistant sealing ring 12 includes polyimide and polyether ether ketone.

[0022] Embodiment 2

[0023] The steam generating cabin 1 in the corrosion resistance test device under the working condition of the heat exchange pipe in the embodiment is in a cylindrical structure and is sealed at both ends through the inner sealing flange 2 and the outer sealing flange 3. The outer sealing flange 3 presses the inner sealing flange 2 and the pressure maintaining nut 11 to guarantee the pressure in the steam generating cabin 1. The heating temperature range of the heating pipe 6 is 25-450℃. The material of the heat exchange pipe 8 is copper-nickel alloy, the outer diameter is 16mm and the wall thickness is 1.5mm. The main body structure of the heating control device 9 includes a display screen, a power indicator, a running indicator and a switch. The display screen is used to display the temperature in the steam generating cabin 1 in real time. The pressure maintaining nut 11 is used to press the high-temperature-resistant sealing ring 12 to prevent the steam generating cabin 1 from leaking. The material of the high-temperature-resistant sealing ring 12 is polyether ether ketone.

[0024] The corrosion resistance test device under the working condition of the heat exchange pipe in this embodiment is used to test the corrosion influence of the combined working condition of microorganisms and foreign matter blockage on the copper-nickel alloy heat exchange pipe. The heating temperature is set to 100°C, the foreign matter blockage is preformed in the heat exchange pipe 8, and the cooling water with a flow rate of 2.5 m / s is introduced. The cooling water is seawater containing sea mud.

Claims

1. A device for testing corrosion resistance of a heat exchange tube under working conditions, characterized in that, The main body structure comprises a steam generation cabin, two sealing flanges arranged at two ends of the steam generation cabin, a heating pipe or a heating sleeve arranged outside the steam generation cabin, a temperature feedback device arranged inside the steam generation cabin, and a heat exchange pipe; the two sealing flanges are connected through locking bolts and locking nuts, the temperature feedback device is connected with the heating pipe or the heating sleeve through a heating control device by penetrating the inner sealing flange at one end, the heat exchange pipe is connected with external cooling water by penetrating the sealing flanges at two ends, and the inner sealing flange is connected with the temperature feedback device and the heat exchange pipe through pressure maintaining studs and pressure maintaining nuts.

2. The heat exchange tube corrosion resistance test device under working condition according to claim 1, characterized in that, The material of the steam generation cabin comprises titanium and stainless steel, titanium is used when the steam generation cabin contains corrosive medium, and stainless steel or titanium is used when the steam generation cabin contains solution with a chlorine ion concentration of less than 100 ppm.

3. The heat exchange tube corrosion resistance test device of claim 1, wherein The outer sealing flange is in a right-angle U-shaped structure.

4. The heat exchange tube corrosion resistance test device under working condition according to claim 1, characterized in that, The heating pipe cooperates with the temperature feedback device and the heating control device to heat the steam generation cabin to a set value.

5. The heat exchange tube corrosion resistance test device of claim 1, wherein The number of the heat exchange pipes is an integer greater than or equal to 1.

6. The heat exchange tube corrosion resistance test device of claim 1, wherein The pressure maintaining studs are in a hollow structure, have the same material as the steam generation cabin, and are connected with the steam generation cabin through welding or are integrally processed and formed.

7. The heat exchange tube corrosion resistance test device according to any one of claims 1 to 6, characterized in that, The principle is as follows: the steam generation cabin is heated by the heating pipe or the heating sleeve, the solution in the steam generation cabin is heated to become steam in a limited space, high-temperature steam working conditions are formed, cooling water is introduced into the heat exchange pipe, and the corrosion resistance of the heat exchange pipe is tested under the high-temperature steam working conditions; when the temperature in the steam generation cabin is lower than the set value, the temperature feedback device transmits a signal to the heating control device, the heating control device controls the heating pipe to start heating, and when the temperature in the steam generation cabin reaches the set value, the temperature feedback device transmits a signal to the heating control device, and the heating control device controls the heating pipe to stop heating; When the corrosion influence of simulated deposits or marine organisms on the heat exchange pipe is simulated, the deposits or marine organisms are prefabricated in the heat exchange pipe in advance; When the corrosion influence of simulated microorganisms or hard particles on the heat exchange pipe is simulated, microorganism-rich cooling water or hard particle-rich cooling water is used for the test; When the corrosion influence of temperature difference on the heat exchange pipe is simulated, the test is performed by controlling the temperature of the cooling water and the steam temperature.

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