A temperature-controlled thermal cycling test device

Abstract

The patent relates to a temperature-controlled cold-heat cycle test device for power equipment temperature rise and cold-heat cycle test. The temperature-controlled cold-heat cycle test device comprises an insulation box, the top outlet of the insulation box is connected with one end of a liquid outlet pipe, the bottom inlet of the insulation box is connected with a liquid inlet pipe, the other end of the liquid outlet pipe is connected with the inlet of a heating device, the other end of the liquid inlet pipe is connected with the outlet of the heating device, and the outlet of the heating device is connected with one end of the liquid inlet pipe. A loading table is further arranged in the insulation box, and the loading table is used for placing a test sample. The device is mainly applied to the cold-heat cycle test scene of a generator wire rod and is used for the accelerated aging experiment of the generator wire rod.

Description

Technical Field

[0001] This utility model relates to the field of temperature-controlled thermal cycling, and specifically to a temperature-controlled thermal cycling test device. Background Technology

[0002] Thermal cycling testing is a crucial method for evaluating the insulation and conductivity of electrical equipment. However, standardized thermal cycling testing equipment is lacking in the market. This test assesses the performance stability of insulating materials and conductive devices during dynamic operation. Existing thermal cycling testing equipment has several significant shortcomings in the field of electrical equipment testing, failing to meet the demands for high precision and reliability. Insufficient temperature control accuracy is a common problem, with most equipment exhibiting temperature fluctuations exceeding ±2℃. This instability leads to distortion in the simulation of thermal stress in insulating materials. For example, when assessing the weather resistance of cable accessories, temperature deviations may mask microcracks in the material, affecting the reliability of the test results.

[0003] The circulation rate adjustment is limited. The heating and cooling rates of traditional equipment are mostly fixed within 5℃ / min, and cannot accurately match the dynamic temperature changes in actual operation of power equipment. When the load of a power transformer changes abruptly, the winding temperature may fluctuate by 30℃ within 10 minutes, and existing equipment cannot reproduce such operating conditions, resulting in inaccurate assessment of the dynamic changes in the contact resistance of conductive components.

[0004] The testing capacity and compatibility are inadequate. Small and medium-sized equipment can only accommodate small samples such as cables and insulators, which cannot meet the overall testing needs of large power equipment such as GIS switchgear and high-voltage switchgear. At the same time, the equipment interface lacks standardized design, and data transmission delays or signal interference often occur when interfacing with monitoring instruments from different manufacturers (such as partial discharge detectors).

[0005] The level of automation is low. Most equipment still relies on manual recording of temperature curves and sample conditions, lacking the function of automatically identifying the inflection point of material thermal aging. In hundreds of cycle tests, manual operation is not only inefficient, but may also lead to the omission of key data due to fatigue, affecting the accuracy of equipment life assessment.

[0006] There are shortcomings in safety protection. The high and low temperature switching devices of some equipment are not sufficiently sealed, which can easily lead to refrigerant leakage in the low temperature range and aging of the insulation layer due to thermal cycling in the high temperature range, causing frost formation or localized overheating of the chamber. This not only affects the continuity of the test, but may also cause secondary damage to expensive electrical equipment samples, increasing the test cost.

[0007] These shortcomings make it difficult for existing equipment to fully simulate the operating conditions of power equipment under complex environments such as extreme climates and load fluctuations, thus limiting in-depth evaluation of insulation and conductivity performance. The aim is to develop a device that uses liquid temperature control to create a stable temperature environment, allowing the same equipment to handle both hot and cold state transitions. Utility Model Content

[0008] This invention aims to solve the problems of long testing time and low efficiency of cold and hot cycle tests for generator bars. This device can shorten the test cycle for measuring the cold and hot cycle test of generator bars.

[0009] To solve the above problems, this application provides the following technical solution: A temperature-controlled thermal cycling test device includes an insulated chamber, wherein the top outlet of the insulated chamber is connected to one end of an outlet pipe, and the bottom inlet of the insulated chamber is connected to an inlet pipe. The other end of the outlet pipe is connected to the inlet of the heating device, the other end of the inlet pipe is connected to the outlet of the heating device, and the outlet of the heating device is connected to one end of the inlet pipe.

[0010] The insulated box is also equipped with a stage for placing the sample.

[0011] A stirring device is also fixedly installed at the bottom of the insulated box.

[0012] A heat exchanger is also fixedly installed on the top of the insulation box, and the spiral heat exchanger tubes are connected inside the insulation box.

[0013] The heating device is electrically connected to the temperature measuring and control device via a signal line. The two poles of the temperature measuring and control device are electrically connected to the two ends of the sample via resistance test lines. The temperature measuring and control device is equipped with a PLC controller.

[0014] The control terminal of the heating device is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measurement and control device via a signal line.

[0015] The control terminal of the stirring device is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measurement and control device.

[0016] The control terminal of the heat exchanger is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measurement and control device.

[0017] The temperature measurement and control device is electrically connected to the recording device.

[0018] The temperature measurement and control device also contacts the sample via optical fiber.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This device is mainly used in the cold and hot cycle test of generator bars for accelerated aging tests of generator bars.

[0020] 2. This device adopts a dual measurement and control method, which measures the internal temperature with resistance test measuring line 302 and the surface temperature with temperature measuring fiber 303. It can be used for aging tests of generator bars in existing generator stator windings, and for cold and hot cycle tests of generator bars made of copper and aluminum conductors. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0022] Reference numerals: Heating device 1, inlet pipe 101, outlet pipe 102, heat preservation box 2, stage 201, temperature measuring and control device 3, signal line 301, resistance test line 302, temperature measuring fiber optic cable 303, sample 4, recording device 5, stirring device 6, heat exchanger 7, heat exchange tube 701. Detailed Implementation

[0023] It should be understood that the terms "top," "bottom," "other end," "one end," "inside," "both ends," and "output end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Unless otherwise specified, the "fixed connection" described in this application refers to conventional methods such as bonding.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "equipped with," "featured," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] Furthermore, the description of this invention is merely a preferred embodiment and is not intended to limit the invention. Although the invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

[0026] The model numbers selected in this patent are merely for ease of explanation and are not intended to restrict the use of any particular instrument model. Those skilled in the art can refer to the instrument model information selected in this patent, purchase or consult the general operating instructions for the relevant instrument models, and thus master the specific operating methods. Therefore, this patent does not describe in detail the specific operating methods of each instrument.

[0027] Example 1 A temperature-controlled thermal cycling test device includes an insulated chamber 2, with its top outlet connected to one end of an outlet pipe 101 and its bottom inlet connected to an inlet pipe 102. The other end of the liquid outlet pipe 101 is connected to the inlet of the heating device 1, the other end of the liquid inlet pipe 102 is connected to the outlet of the heating device 1, and the outlet of the heating device 1 is connected to one end of the liquid inlet pipe 102.

[0028] The insulated box 2 is also equipped with a stage 201, which is used to place the sample 4.

[0029] A stirring device 6 is also fixedly installed at the bottom of the insulated box 2.

[0030] A heat exchanger 7 is also fixedly installed on the top of the insulation box 2, and the spiral heat exchange tube 701 of the heat exchanger 7 is connected to the inside of the insulation box 2.

[0031] Heating device 1 is electrically connected to temperature measuring and control device 3 via signal line 301. The two poles of temperature measuring and control device 3 are electrically connected to the two ends of sample 4 via resistance test line 302. Temperature measuring and control device 3 is equipped with a PLC controller.

[0032] The control terminal of the heating device 1 is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measurement and control device 3 through signal line 301.

[0033] The control terminal of the stirring device 6 is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measuring and control device 3.

[0034] The control terminal of heat exchanger 7 is electrically connected to the output terminal of the control signal of the PLC controller of temperature measurement and control device 3.

[0035] Temperature measurement and control device 3 is electrically connected to recording device 5.

[0036] The temperature measurement and control device 3 also contacts the sample 4 via optical fiber 303.

[0037] The water in the heat exchange tube 701 comes into countercurrent heat exchange contact with the silicone oil in the insulation box 2.

[0038] The outer side of the insulated box 2 is fixedly connected with a layer of heat-insulating rock wool board, and the inside is coated with a layer of oleophobic epoxy zinc-rich paint.

[0039] Preferably, the rock wool board is purchased from Hebei Jixing Insulation Materials Co., Ltd. as Grade A 5mm rock wool board.

[0040] Preferably, the epoxy zinc-rich paint was purchased from Shuangshi Coatings Technology Tianjin Co., Ltd., model: ZD300, with a zinc content of 30%.

[0041] Preferably, the high-boiling-point liquid in the insulation box 2 is a general-purpose silicone oil. The silicone oil is purchased from Qingdao Meiside Silicone Co., Ltd., and is a high-temperature resistant silicone oil. The advantage of using silicone oil for circulating heating is that it prevents localized overheating.

[0042] Preferably, the temperature measurement and control device 3 is purchased from Siemens S7-1500 model and its related power supply and circuit; the temperature measurement and control device 3 includes a PLC controller and its related power supply and circuit.

[0043] Preferably, signal cable 301 is purchased from Tiancheng Company as a TC-CAT6A model network cable.

[0044] Preferably, the resistance test lead 302 was purchased from Baoding Jinyuan Company, model 4 square millimeters.

[0045] Preferably, the 303 optical fiber is purchased from Fiberhome Technologies Co., Ltd., and the model is single-core optical fiber.

[0046] Preferably, sample 4 is a generator rod, the insulation layer of sample 4 is an epoxy powder mica insulation layer, and sample 4 is purchased from Dongfang Electric 700MW air-cooled unit model.

[0047] Preferably, the recording device 5 is purchased from Siemens, model: PLC recorder and its related power supply and circuit.

[0048] Preferably, the stirring device 6 is purchased from Bosch, model: stirring device, along with its related power supply and circuit.

[0049] Preferably, heat exchanger 7 is a water cooling heat exchanger, purchased from Changsha Dongwu Company, model: oil-water cooler and its related power supply and circuit.

[0050] Preferably, the heating device 1 is purchased from Suzhou Xinjiuyang Machinery Equipment Co., Ltd., model: explosion-proof thermal oil heater 24KW and its related power supply and circuit.

[0051] Insulated Box 2: The box has a double-layer structure. The outer layer is made of rock wool board for insulation, and the inner layer is made of copper plate with strong thermal conductivity. It was purchased from Zijin Mining Company and its model is T2 copper.

[0052] The heat transfer medium for the insulation box 2 is silicone oil, and water cooling is used.

[0053] The high-boiling-point, low-freezing-point liquid in the insulation box 2 is a general-purpose silicone oil. The silicone oil was purchased from Qingdao Meiside Silicone Co., Ltd., and the model is high-temperature resistant silicone oil.

[0054] Heating device 1 is used to heat the silicone oil.

[0055] Heat exchanger 7 is used to cool the silicone oil. The inlet end of heat exchanger 7 is connected to a cold water source at 0°C, and the outlet end of heat exchanger 7 is connected to a cooling pool.

[0056] Heating device 1 and heat exchanger 7 provide a hot and cold circulation environment; Heating is achieved using a conventional resistance wire heating method, while cooling is achieved using a compressor cooling method.

[0057] Temperature measurement and control employs two methods. The temperature of the insulating layer on the surface of sample 4 was measured by deploying distributed temperature-sensing optical fibers 303. The conductor of resistance test lead 302 is a copper core wire. The internal temperature of sample 4 was measured by measuring the conductor resistance of resistance test line 302 and converting it into temperature.

[0058] Sample 4 is a generator conductor, and the material of sample 4 is copper or aluminum conductor. The temperature measurement and control device 3 measures the conductor resistance of the resistance test line 302 in real time and then outputs the temperature data to the recording device 5. The temperature measurement and control device 3 also measures the temperature of the distributed temperature-sensing optical fiber 303 in real time and outputs the temperature data to the recording device 5.

[0059] Fiber optic cable 303 measures the temperature of the surface insulation layer of sample 4, while resistance test wire 302 measures the temperature of the internal conductor of sample 4. The experimental steps for the hot and cold cycling of this device are as follows: S1. Before use, add silicone oil to the liquid insulation tank 2 and connect and check the pipes to ensure there are no leaks.

[0060] S2. Place the sample 4 into the heat preservation box 2. The heating device 1 heats the silicone oil in the heat preservation box 2 to the set temperature of 220°C and keeps it constant until the temperature inside and outside the sample 4 reaches the set temperature of 220°C.

[0061] S3. The heating device 1 will first heat the sample 4 to 220°C, then the heating device 1 will stop working and the heat exchanger 7 will be turned on to cool it down until the internal temperature of the sample 4 drops to room temperature of 20°C.

[0062] S4. Repeat steps S2-S3 until the set number of cycles is reached, then stop the experiment. The staff will find the number of cycles of the recorded experimental data in the recording device 5.

[0063] The number of cycles in step S4 refers to the number of hot and cold cycles specified in standard T / CEEIA252-2016.

[0064] Before the surface temperature of sample 4 reaches the set temperature of 220℃ as measured by the temperature-sensing fiber optic cable 303, the heating device 1 continues to heat the sample 4 at a heating rate of 5℃ / min until the surface temperature reaches 220℃. After the surface temperature of sample 4 reaches the set temperature of 220℃ as measured by the temperature-sensing fiber optic cable 303, the heating device 1 continues to heat the sample 4 until the surface temperature reaches a constant temperature of 220℃ as measured by the resistance test line 302. This indicates that the internal and external temperatures of sample 4 have reached the set temperature of 220℃, and the heating device 1 stops heating.

[0065] Turn on heat exchanger 7 to cool sample 4 at 5℃ / min until the internal temperature of sample 4 measured by resistance test line 302 drops to room temperature (20℃). This completes one thermal cycle experiment.

[0066] This allows for the simulation of thermal cycling tests on electrical equipment to accelerate the aging of sample 4 and quickly obtain its aging characteristics.

[0067] When the machine is stopped, the silicone oil in the incubator 2 can be recovered for reuse in the next experiment.

Claims

1. A temperature-controlled thermal cycling test device, characterized in that, Includes an insulated box (2), the top outlet of which is connected to one end of the liquid outlet pipe (101), and the bottom inlet of which is connected to the liquid inlet pipe (102). The other end of the outlet pipe (101) is connected to the inlet of the heating device (1), the other end of the inlet pipe (102) is connected to the outlet of the heating device (1), and the outlet of the heating device (1) is connected to one end of the inlet pipe (102).

2. The temperature-controlled thermal cycling test device according to claim 1, characterized in that, The heat preservation box (2) is also equipped with a stage (201) for placing the sample (4).

3. The temperature-controlled thermal cycling test device according to claim 1, characterized in that, The bottom of the insulated box (2) is also fixedly equipped with a stirring device (6).

4. The temperature-controlled thermal cycling test device according to claim 1, characterized in that, A heat exchanger (7) is also fixedly installed on the top of the heat exchanger (2), and the spiral heat exchange tube (701) of the heat exchanger (7) is connected to the inside of the heat exchanger (2).

5. The temperature-controlled thermal cycling test device according to claim 1, characterized in that, The heating device (1) is electrically connected to the temperature measuring and control device (3) via a signal line (301). The two poles of the temperature measuring and control device (3) are electrically connected to the two ends of the sample (4) via resistance test lines (302). The temperature measuring and control device (3) is equipped with a PLC controller.

6. The temperature-controlled thermal cycling test device according to claim 1, characterized in that, The control terminal of the heating device (1) is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measurement and control device (3) through a signal line (301).

7. The temperature-controlled thermal cycling test device according to claim 3, characterized in that, The control terminal of the stirring device (6) is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measuring and control device (3).

8. The temperature-controlled thermal cycling test device according to claim 4, characterized in that, The control terminal of the heat exchanger (7) is electrically connected to the output terminal of the control signal of the PLC controller of the temperature measurement and control device (3).

9. A temperature-controlled thermal cycling test device according to claim 5, characterized in that, The temperature measurement and control device (3) is electrically connected to the recording device (5).

10. A temperature-controlled thermal cycling test device according to claim 5, characterized in that, The temperature measurement and control device (3) also contacts the sample (4) via an optical fiber (303).

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