As a precision equipment for simulating temperature environments, the installation quality of the thermal shock test chamber directly affects the performance and service life of the equipment. The scientific and standardized installation process needs to take into account four core aspects: environmental adaptation, mechanical positioning, electrical safety, and system debugging. The following are the key implementation points:
1、 Environmental Site Selection and Spatial Planning
Prioritize choosing a constant temperature location with temperature fluctuations of ≤ ± 2 ℃/h, away from heat sources (such as ovens), vibration sources (centrifuges), and areas with strong electromagnetic interference. A heat dissipation space of ≥ 80cm should be reserved behind the equipment, and operation and maintenance channels of ≥ 60cm should be reserved on both sides and the top. The ground bearing capacity needs to meet the full load weight of the equipment (including the sample rack). It is recommended to use anti-static epoxy flooring and adjust the height of the equipment's four legs with a level to ensure that the verticality deviation of the box is less than 1mm
2、 Basic fixation and shock absorption treatment
Use expansion bolts to firmly connect the equipment base to the concrete foundation, and the bolt specifications must comply with the equipment manual requirements. If placed on the second floor or above, the load-bearing limit of the floor slab must be verified. To reduce vibration transmission during operation, rubber shock absorbers can be installed at the bottom of the equipment and ensure that all support feet are on the ground. For mobile models with casters, the universal wheel braking device should be locked after installation.
3、 Accurate docking of electrical systems
Strictly follow the electrical schematic to complete the line laying, and the input voltage should be consistent with the equipment nameplate markings (commonly 380V three-phase five wire system). An air switch is separately installed in the distribution box, with a capacity 30% higher than the rated power of the equipment. The grounding resistance must be less than 4 Ω, and a yellow green dual color dedicated grounding wire should be used. The grounding point should be away from non-conductive pipelines such as water pipes and gas pipes. The cable wiring follows the principle of "separation of strong and weak electricity", and the signal lines use shielded cables and are properly grounded.
4、 Joint debugging of refrigeration/heating system
Before installation, check the sealing of the copper pipe interface to prevent refrigerant leakage caused by virtual connections. When adding environmentally friendly refrigerants (such as R404A), an electronic scale should be used for accurate measurement, and impurities are strictly prohibited from being mixed in. The heating wire terminal should be coated with thermal conductive silicone grease to improve heat transfer efficiency. After completing the filling, perform a pressure holding test: close all valves, start the compressor to increase the system pressure to 1.8MPa, and maintain it for 24 hours. If the pressure drop does not exceed 5%, it is considered qualified.
5、 Optimization configuration of air duct system
The smoothness of the interior walls of the workspace directly affects the uniformity of airflow. Before installation, clean the residue inside the cavity. The spacing between sample racks should be adjusted according to the size of the sample, ensuring that the distance between the upper and lower rows is ≥ 15cm to ensure airflow circulation. The rotation direction of the evaporator fan and condenser fan should meet the design requirements, and the rotation direction can be determined by lightly touching the blades. The temperature sensor should be hung at the geometric center of the workspace to avoid measurement deviation caused by being close to the wall.
6、 Control system calibration and testing
Confirm that the PLC controller address code is set correctly and the touch screen communication is normal before powering on. Perform the no-load operation program for the first startup: set a temperature shock cycle of -70 ℃ →+150 ℃ → -70 ℃, and observe whether the heating/cooling rate meets the national standard (such as the conversion time specified in GJB150.5 ≤ 5 minutes). Use a standard platinum resistance thermometer to verify the actual temperature in each temperature zone, with an error controlled within ± 2 ℃.
7、 Complete safety protection and signage
Set up protective barriers around the equipment, and install emergency stop buttons in easily accessible locations for operators. The high/low temperature alarm threshold needs to be set in advance, and the heating or cooling system should be automatically cut off when the temperature exceeds the limit. Post warning signs in prominent locations, indicating phrases such as "high temperature danger" and "no disassembly of protective covers". Establish equipment file cards to record installation dates, calibration data, and maintenance cycles.
Correct installation is the foundation for the optimal performance of the thermal shock test chamber. Through strict environmental control, precise system debugging, and comprehensive safety measures, the lifespan of equipment can be effectively extended, ensuring the accuracy and repeatability of temperature shock experiments. It is recommended to have the installation guided by the manufacturer's engineer on site and provide specialized training for the operators.