Fatigue index testing system and method for single-channel pressure-bearing heat exchange equipment

Abstract

The invention discloses a fatigue index testing system and method for single-channel pressure-bearing heat exchange equipment, and belongs to the field of steam power. The method solves the problem that whether the fatigue index of the pressure-bearing heat exchange equipment meets the use condition or not is difficult to confirm before the pressure-bearing heat exchange equipment is mounted in the prior art. According to the invention, a fatigue index test system of the pressure-bearing heat exchange equipment is established, a strain gauge is pasted at a main pressure-bearing part for testing according to a finite element simulation calculation result, a cyclic process of boosting, pressure maintaining, pressure reducing and boosting of the equipment is realized through an electric pressure test pump, and required pressurization cycle times and data acquisition and analysis are completed. According to the method, whether the pressure-bearing fatigue index of the single-channel pressure-bearing heat exchange equipment can meet the use condition or not can be confirmed before the single-channel pressure-bearing heat exchange equipment is mounted, the use risk after the equipment is mounted is maximally solved, and safe and stable operation of a steam power system is ensured.

Description

Technical Field

[0001] The invention relates to a fatigue index testing system and method for single-channel pressure-bearing heat exchange equipment, belonging to the field of steam power. Background Art

[0002] In the steam power system, the condenser and the vacuum pump are the main heat exchange equipment. The condenser and the vacuum pump are subjected to seawater pressure during operation and adopt a single-channel structure. The condenser is used to receive the steam discharged after the turbine works, and condense the steam into condensed water for recycling. The function of the vacuum pump is to prevent the condensed water from accumulating inside the turbine and to ensure that there are no tiny water droplets in the exhaust steam. The condenser and the vacuum pump are divided into the tube side and the shell side. The shell side medium is steam and condensed water, and the tube side medium is circulating water. The core component is the heat transfer tube bundle. The tube side includes components such as the water chamber, tube sheet and heat transfer tube. Among them, the heat transfer tube, tube sheet and connecting sealing components are the main pressure-bearing parts. In the working state, the circulating cooling water flows in the water chamber and the heat transfer tube, so the pressure of the water in the pressure-bearing part is constantly changing. Condensers and vacuum pumps are the most important pressure-bearing equipment in steam power systems. Their reliability is an important guarantee for safe and reliable operation throughout their life cycle. The existing technology usually only performs simplified tests or calculation estimates on fatigue indicators before the equipment is installed, while the present invention can simulate more severe operating environments, such as seawater and other operating conditions, to ensure the safe and stable operation of the steam power system. Summary of the invention

[0003] The present invention aims to solve the problem in the prior art that it is difficult to confirm whether the fatigue index of a single-channel pressure heat exchange device can meet the use conditions before installation, and provides a fatigue index testing system and method for a single-channel pressure heat exchange device.

[0004] A fatigue index test system for a single-channel pressure-bearing heat exchange equipment, comprising a control module, a pressurizing module, a water tank, a test module, and a data acquisition module;

[0005] The control module is used to control the start, stop, pressure increase and pressure reduction of the pressurization module, including an industrial control unit, a pressure sensor and an overpressure alarm component;

[0006] The industrial control unit is connected to the pressurizing module and is used to control the start, stop, voltage increase and voltage reduction of the pressurizing module;

[0007] A pressure sensor, used to transmit the pressure data of the test module to the overpressure alarm component;

[0008] The overpressure alarm component is used to transmit an alarm signal to the industrial control unit when the pressure on the test module exceeds the set value. It can alarm when the overpressure reaches 5% of the upper limit of the cycle pressure and transmit the alarm signal to the industrial control unit, which will shut down the system.

[0009] The pressurizing module is used to increase or decrease the pressure of the test module, and includes an electric pressure test pump, a proportional electromagnetic overflow valve and a reversing valve, and a safety device;

[0010] The electric pressure test pump is connected to the water tank and is used to increase and reduce the pressure of the test module. When increasing the pressure, the electric pressure test pump pumps the water in the water tank into the test module. When reducing the pressure, the electric pressure test pump releases the pressure, and the water in the test module is discharged into the water tank.

[0011] The proportional electromagnetic overflow valve and reversing valve are placed on the pipeline connecting the electric pressure test pump and the water tank to control the overflow pressure and water flow direction during the pumping and draining process;

[0012] Safety device used to ensure smooth increase and decrease of pressure in the pressurizing module.

[0013] The water tank is used to store water. When the pressure is increased, the pressurizing module pumps the water in the water tank into the test module. When the pressure is reduced, the water in the test module is discharged into the water tank.

[0014] The test module is used to test whether the fatigue index of the single-channel pressure heat exchange equipment meets the requirements.

[0015] The data acquisition module is used to collect and store data measured by the strain gauge in the test module.

[0016] A fatigue index testing method for a single-channel pressure heat exchange equipment comprises the following steps:

[0017] Step 1: Perform finite element simulation on the single-channel pressure heat exchange equipment to simulate the pressurization process. According to the simulation results, the main pressure-bearing parts of the single-channel pressure heat exchange equipment are selected as test points, and strain gauges are pasted on the positions of various test points.

[0018] Step 2: Determine the load size and the number of pressurization cycles according to the operating conditions and technical requirements of the single-channel pressure heat exchange equipment, and divide the load into five levels;

[0019] Step 3: The test module first raises the load to level 1 and maintains it for T1 time, records the data of each test point, and then continues to pressurize to the next pressure level until all five levels of load are pressurized;

[0020] Step 4: Completely exhaust the air in the pressurizing device, and the industrial control unit controls the electric pressure test pump to pressurize the test module to the highest load, maintain the time T2, and then release the pressure to zero load, and then pressurize to the highest load and maintain the time T2, and then release the pressure to zero load, and repeat this process for the specified number of tests. The data acquisition module collects data from each test point during the pressurization and pressure relief process;

[0021] Step 5: The test module first raises the load to level 1 and maintains it for T1 time, records the data of each test point, and then continues to pressurize to the next pressure level until all five levels of load are pressurized;

[0022] Step 6. Compare the data collected in step 3 and step 5. If the stress of each test point does not change when the single-channel pressure heat exchange equipment is subjected to the same load twice, the fatigue index of the single-channel pressure heat exchange equipment meets the requirements. If the stress changes when the single-channel pressure heat exchange equipment is subjected to the same load twice, the fatigue index of the single-channel pressure heat exchange equipment does not meet the requirements.

[0023] Furthermore, the test equipment is observed throughout the test. If the single-channel pressure heat exchange equipment has an abnormal phenomenon of sealing structure leakage, the test is stopped and the fatigue index of the single-channel pressure heat exchange equipment does not meet the requirements. If the single-channel pressure heat exchange equipment has an abnormal phenomenon that is not caused by damage to the equipment itself, the abnormality is handled and the test is continued.

[0024] Furthermore, the test point in step one is located at a pressure-bearing portion of a non-pipeline area of ​​a tube sheet of a single-channel pressure heat exchange equipment.

[0025] Furthermore, the strain gauge in step one is a waterproof three-way strain gauge.

[0026] The beneficial effects of the present invention are:

[0027] The present invention has built a fatigue index test system for pressure-bearing heat exchange equipment, and based on the finite element simulation results, strain gauges are attached to the main pressure-bearing parts for testing. The electric pressure test pump is used to realize the equipment's pressure-boosting-pressure-maintaining-pressure-reducing-pressure-boosting cycle process, and the required number of pressurization cycles and data collection and analysis are completed. The present invention can confirm whether the pressure-bearing fatigue index of the pressure-bearing heat exchange equipment meets the technical requirements before installation, and minimize the use risks of the equipment after installation, ensuring the safe and stable operation of the steam power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a system diagram of the present invention;

[0029] Figure 2 Schematic diagram of the arrangement of strain gauges in the present invention. DETAILED DESCRIPTION Specific implementation method one:

[0031] This embodiment is a fatigue index test system for a single-channel pressure heat exchange equipment. Figure 1 This embodiment is described, including a control module, a pressurizing module, a water tank, a testing module, and a data acquisition module.

[0032] The control module is used to control the start, stop, pressure increase and pressure reduction of the pressurization module, including an industrial control unit, a pressure sensor and an overpressure alarm component;

[0033] The industrial control unit is connected to the pressurizing module and is used to control the start, stop, voltage increase and voltage reduction of the pressurizing module;

[0034] A pressure sensor, used to transmit the pressure data of the test module to the overpressure alarm component;

[0035] The overpressure alarm component is used to transmit an alarm signal to the industrial control unit when the pressure of the test module exceeds the set value. It can also alarm when the overpressure reaches 5% of the upper limit of the cycle pressure and transmit the alarm signal to the industrial control unit, which will shut down the system.

[0036] The pressurizing module is used to increase and reduce the pressure of the test module. During the test, the pressurizing module remains sealed and can adjust the flow rate to achieve smooth pressure increase and keep the waveform of each pressure cycle basically consistent. The pressurizing module includes an electric pressure test pump, a proportional electromagnetic overflow valve and a reversing valve, and a safety device;

[0037] The electric pressure test pump is connected to the water tank and is used to increase and reduce the pressure of the test module. When increasing the pressure, the electric pressure test pump pumps the water in the water tank into the test module. When reducing the pressure, the electric pressure test pump releases the pressure, and the water in the test module is discharged into the water tank.

[0038] The proportional electromagnetic overflow valve and reversing valve are placed on the pipeline connecting the electric pressure test pump and the water tank to control the overflow pressure and water flow direction during the pumping and draining process;

[0039] Safety device, used to ensure safe and stable voltage boost and voltage reduction process.

[0040] The water tank is used to store water. When the pressure is increased, the pressurizing module pumps the water in the water tank into the test module. When the pressure is reduced, the water in the test module is discharged into the water tank.

[0041] The test module is used to test whether the fatigue index of the single-channel pressure heat exchange equipment meets the requirements.

[0042] The data acquisition module is used to collect and store data measured by the strain gauge in the test module. Specific implementation method 2:

[0044] This embodiment is a fatigue index testing method for a single-channel pressure heat exchange equipment, comprising the following steps:

[0045] Step 1: Perform finite element simulation on the single-channel pressure heat exchange equipment to simulate the pressurization process. According to the simulation results, select the main pressure-bearing parts of the single-channel pressure heat exchange equipment as the test point positions, and paste the strain gauges on each test point position. The strain gauges used are waterproof three-dimensional strain gauges with a resistance of 120Ω, no less than 20, and no less than 60 channels. In order to detect the stress of the heat transfer tube, select no less than three heat transfer tubes as the target. The test point positions are as follows: Figure 2The figure shows the non-pipeline area of ​​the tube sheet of a single-channel pressure heat exchanger that is subject to high stress. Before pasting the strain gauge, you must first draw a line on the surface of the test piece to determine the pasting position, then polish the surface and scrub it with acetone. After drying, use a special adhesive to paste the strain gauge according to the strain gauge pasting requirements, and then conduct the test 24 hours later.

[0046] Step 2: Determine the load size and the number of pressurization cycles according to the operating conditions and technical requirements of the single-channel pressure heat exchange equipment, and divide the load into five levels.

[0047] Step 3: The test module first increases the load to level 1 and maintains it for 5 minutes, records the strain data of each test point, and then continues to pressurize to the next pressure level until all five levels of load are pressurized;

[0048] Step 4: Completely exhaust the air in the pressurizing device, and the industrial control unit controls the electric pressure test pump to pressurize the test module to the highest load, hold for 10 seconds, and then release the pressure to zero load, then pressurize to the highest load and hold for 10 seconds, and then release the pressure to zero load, and repeat this process for the specified number of tests. The data acquisition module collects data from each test point during the pressurization and pressure relief process;

[0049] Step 5: The test module first increases the load to level 1 and maintains it for 5 minutes, records the strain data of each test point, and then continues to pressurize to the next pressure level until all five levels of load are pressurized;

[0050] Step 6. Compare the data collected in step 3 and step 5. If the stress of each test point does not change when the single-channel pressure heat exchange equipment is subjected to the same load twice, the fatigue index of the single-channel pressure heat exchange equipment meets the requirements. If the stress changes when the single-channel pressure heat exchange equipment is subjected to the same load twice, the fatigue index of the single-channel pressure heat exchange equipment does not meet the requirements.

[0051] In addition, the test equipment is observed throughout the test process. If the single-channel pressure heat exchange equipment has abnormal phenomenon of sealing structure leakage, the test will be stopped and the fatigue index of the single-channel pressure heat exchange equipment will not meet the requirements. If the single-channel pressure heat exchange equipment has abnormal phenomenon that is not caused by damage to the equipment itself, the abnormality will be handled and the test will continue.

Claims

1. A fatigue index testing system for a single-channel pressure heat exchange equipment, characterized in that: Including control module, pressurization module, water tank, test module and data acquisition module; The control module is used to control the start, stop, pressure increase and pressure reduction of the pressurizing module; The pressurizing module is used to increase or decrease the pressure of the test module; The water tank is used to store water. When the pressure is increased, the pressurizing module pumps the water in the water tank into the test module. When the pressure is reduced, the water in the test module is discharged into the water tank. The test module is used to test whether the fatigue index of the single-channel pressure heat exchange equipment meets the requirements; The data acquisition module is used to collect and store data measured by the strain gauge in the test module.

2. A fatigue index testing system for a single-channel pressure heat exchange equipment according to claim 1, characterized in that: The control module includes an industrial control unit, a pressure sensor, and an overpressure alarm component; The industrial control unit is connected to the pressurizing module and is used to control the start, stop, voltage increase and voltage reduction of the pressurizing module; A pressure sensor, used to transmit the pressure data of the test module to the overpressure alarm component; The overpressure alarm component is used to transmit an alarm signal to the industrial control unit when the pressure of the test module exceeds the set value.

3. A fatigue index testing system for a single-channel pressure heat exchange equipment according to claim 1, characterized in that: The pressurizing module includes an electric pressure test pump, a proportional electromagnetic overflow valve and a reversing valve, and a safety device; The electric pressure test pump is connected to the water tank and is used to increase or decrease the pressure of the test module. When increasing the pressure, the electric pressure test pump pumps the water in the water tank into the test module. When decreasing the pressure, the electric pressure test pump releases the pressure, and the water in the test module is discharged into the water tank. The proportional electromagnetic overflow valve and reversing valve are placed on the pipeline connecting the electric pressure test pump and the water tank to control the overflow pressure and water flow direction during the pumping and draining process; Safety device used to ensure smooth increase and decrease of pressure in the pressurizing module.

4. A fatigue index testing system for a single-channel pressure heat exchange equipment according to claim 1, characterized in that: The overpressure alarm component of the control module can alarm when the overpressure reaches 5% of the upper limit of the circulation pressure, and transmit the alarm signal to the industrial control unit, which controls the system to shut down.

5. A fatigue index testing method for a single-channel pressure heat exchange equipment, characterized in that: The method specifically comprises the following steps: Step 1: Perform finite element simulation on the single-channel pressure heat exchange equipment to simulate the pressurization process. According to the simulation results, the main pressure-bearing parts of the single-channel pressure heat exchange equipment are selected as test points, and strain gauges are pasted on the positions of various test points. Step 2: Determine the load size and the number of pressurization cycles according to the operating conditions and technical requirements of the single-channel pressure heat exchange equipment, and divide the load into five levels; Step 3: The test module first raises the load to level 1 and maintains it for T1 time, records the data of each test point, and then continues to pressurize to the next pressure level until all five levels of load are pressurized; Step 4: Completely exhaust the air in the pressurizing device, and the industrial control unit controls the electric pressure test pump to pressurize the test module to the highest load, maintain the time T2, and then release the pressure to zero load, and then pressurize to the highest load and maintain the time T2, and then release the pressure to zero load, and repeat this process for the specified number of tests. The data acquisition module collects data from each test point during the pressurization and pressure relief process; Step 5: The test module first raises the load to level 1 and maintains it for T1 time, records the data of each test point, and then continues to pressurize to the next pressure level until all five levels of load are pressurized; Step 6. Compare the data collected in step 3 and step 5. If the stress of each test point does not change when the single-channel pressure heat exchange equipment is subjected to the same load twice, the fatigue index of the single-channel pressure heat exchange equipment meets the requirements. If the stress changes when the single-channel pressure heat exchange equipment is subjected to the same load twice, the fatigue index of the single-channel pressure heat exchange equipment does not meet the requirements.

6. A fatigue index testing method for a single-channel pressure heat exchange equipment according to claim 5, characterized in that: The test equipment is observed throughout the test. If the single-channel pressure heat exchange equipment has abnormal phenomenon of sealing structure leakage, the test will be stopped and the fatigue index of the single-channel pressure heat exchange equipment will not meet the requirements. If the single-channel pressure heat exchange equipment has abnormal phenomenon that is not caused by damage to the equipment itself, the abnormality will be handled and the test will continue.

7. A fatigue index testing method for a single-channel pressure heat exchange equipment according to claim 5, characterized in that: The test point in step 1 is located at a pressure-bearing portion of a tube sheet in a non-pipeline area of ​​a single-channel pressure heat exchange equipment.

8. A fatigue index testing method for single-channel pressure heat exchange equipment according to claim 5, characterized in that: The strain gauge in step 1 is a waterproof three-dimensional strain gauge.

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