With the development of the people and the military, the air force and the navigation area, many equipment will work in high temperature, low temperature and high humidity. Applications will face greater challenges in this environment. The stability of the equipment has a significant impact on the performance of the equipment.
High and low temperature test rooms (also known as high and low temperature rooms) are used to evaluate the performance of aerospace components and key products under high pressure. temperature, hot temperature and other environments. Its structure and principles of work have some peculiarity.
- Using high and low temperature room humidity
Before environmental testing, it is important to know the performance of the tested sample, test method, test conditions and test technology. At the same time, it is important to know the technology of using the tool, to understand the structure of the tool, especially to know the performance and function of management. At the same time, users should read the operation manual in detail several times to avoid operation errors. Therefore, the equipment cannot work properly, causing errors in the test data and damage to the test samples. In order to ensure the accuracy of the research data in the experiment, it is important to choose reasonable equipment to use in the experiment. The choice of high and low humidity room should depend on the actual condition of the sample. The volume between the laboratory and the sample should always remain within reasonable limits. When performing the test on a hot test subject, its volume should be less than 10% of the effective volume of the test setup. The number of non-flammable probes and the effective ratio of the laboratory should be 20%.
During testing, the condition of the test object should be maintained properly. The distance between the probe and the wall of the house should be kept at 20 cm. If multiple samples are to be placed during the test, all samples shall be placed in the same plane as possible. The position where the sample is placed should not prevent the entry of air and air, but at the same time, the distance from the humidity sensor should be kept to ensure normal temperature during the experiment.
When using high and low humidity rooms, the following points should be kept in mind:
(1) When in use, ensure that the high and low temperature room is properly grounded to prevent electrostatic induction accidents.
(2) The building should not be touched with hands while it is working.
(3) Unless the door of the building cannot be opened for special reasons during the operation of the equipment, the following negative consequences may occur:
1) The temperature inside the door is still high
2) Too much heat and humidity will come out of the room.
3) High temperatures can trigger fire alarms.
4) Unless it is necessary, the fire must be turned off.
5) Try to avoid frequent opening within 15 minutes during use.
6) When the upper and lower chambers work at low temperatures, it is best to dry for 30 minutes at 60 ℃, and then open the door to avoid icing the evaporator or affect the measurement time of the experiments.
7) During the operation, to ensure the safety of the equipment and the workers, the heating protection in the circuit must be checked regularly.
8) In addition to full-time employees, electricians are also required to participate in the design and testing of equipment.
- Repair and maintenance of common problems
Addressing the problem of high and low humidity rooms
During the high temperature test, if the test probe cannot reach the temperature value required by the test, the electrical system will be checked and the causes of the fault will be removed one by one. If the temperature rises slowly, the air circulation system should be checked and the opening position of the control plate and the air circulation system should be found.
If the temperature rises quickly, the rotation of the air channel will be detected. If the temperature rises quickly, the PID adjustment parameters need to be adjusted. If the temperature rises directly in the heating protection, it can be concluded that the controller has a fault and the controller should be replaced in time.
When the low temperature does not meet the criteria, it is important to observe the temperature change. If the temperature rises when it falls to a certain value or the temperature drops slowly. The first is usually caused by the bad condition of dry equipment. Equipment location and temperature conditions must be respected. If the equipment’s performance requirements are not met, timely changes will be made. If so, the equipment should be checked to see if the laboratory is dry before the low test. If a dry company places test items in the laboratory, if there are many test items placed in the laboratory, the ventilation of the laboratory does not meet the requirements. After eliminating the above causes of failure, if the cooling speed is still slow, it can be determined that there is a problem with the refrigeration system. The refrigeration system needs to be overhauled!
2.2 Contents of equipment maintenance
The main content of infrastructure maintenance includes preventive maintenance and forecasting. In two types of preventive maintenance, this maintenance will be carried out once a week including: cleaning the laboratory of water and condensate collection tank. Maintenance to be carried out by customers in special rooms including: washing of hot water pipes, washing of systems or cooling water pipes. The maintenance that should be done every six months includes the cleaning of the air cooling equipment (condenser) and the maintenance that should be done every year, Clean the scale in the humidifier, dust and AC contactor maintenance electrical cabinet sign (high current). At the same time, the forced oil used by the compressor should be replaced every 2-3 years. Predictive maintenance includes weekly maintenance, monthly maintenance and quarterly maintenance.
Weekly maintenance includes: checking the balance pressure and compressor intake and exhaust pressure, checking the oil colour in the compressor and checking the oil body. Monthly maintenance included. Check the compressor discharge and water temperature, the liquid level in the condenser and discharge temperature, and the difference between the water entering and leaving the cold water pipe. Check the heating rate and cooling rate of the equipment. Check the operating current of the compressor motor every 15 minutes. Regular maintenance can not only improve the stability of the equipment during operation and the accuracy of the test, but also extend the service life of the equipment to a certain extent. Therefore, special attention will be paid to the management of high and low humidity rooms in the future.
- Conclusion
The high and low heating room is a special refrigerator, so its use, maintenance and repair should start with refrigeration, electrical control, heat engine and other parts. When using, attention should be paid to the specifications for use. During maintenance, the defects that may be caused by operation must be eliminated first, then the defects in the equipment itself must be repaired. When equipment is damaged, maintenance work will be carried out on the basis of knowing the structure of the equipment and the principles of operation. In addition, the equipment must be repaired in time, and the maintenance of the equipment cannot be neglected because the equipment has failed for some time.
