Selection of semi enclosed compressor for high and low temperature test chamber, temperature variable load and cascade scheme
The compressor in the high and low temperature test chamber needs to withstand rapid temperature changes in load, alternating between heating and cooling, with a load fluctuation amplitude of up to 55% of the rated value. Conventional single-stage semi enclosed piston engines are sufficient for temperatures below -40 ℃, while two-stage or R23 cascade schemes are required for temperatures below -60 ℃. Xiteliduo can be customized with test box manufacturers. During the rapid cooling stage of the test chamber, the heat load is 2.3 times that of the constant temperature holding stage, and the compressor selection must be calculated based on the peak cooling load. 1000L high and low temperature test chamber, target -70 ℃, using a cascade system, with a low temperature side R23 compressor displacement of not less than 4.2m ³/h. The compressor refrigeration oil should be suitable for a wide temperature range, with no carbonization in the high temperature range and a pour point that meets the minimum evaporation temperature requirement in the low temperature range. The discharge pressure of the compressor will briefly rise during the rapid cooling stage, and the electronic control needs to set a delay protection to avoid accidental shutdown. The selection of cold storage compressors cannot be directly copied from the test box, as the cold storage load changes slowly and the test box may experience short-term severe thermal shock. Half closed compressor energy regulation is a must-have for test chambers, and it is difficult to stably control the temperature change rate for fixed displacement models. The R404A two-stage model is suitable for a -60 ℃ test chamber, while the R23 cascade is suitable for ultra-low temperature testing requirements of -80 ℃ and below. The maintenance cycle of the compressor is shortened to 2500 hours due to frequent temperature changes, and the valve plates and seals are checked for fatigue damage during each maintenance. Foreign trade environmental equipment manufacturers purchase compressors, and EU project CE needs to include EMC electromagnetic compatibility testing, matched with test box electrical control. Low suction pressure of compressors often occurs during the low-temperature constant temperature stage in the test chamber, and improper matching of refrigerant return and throttling is the main cause. Screw compressors are rarely used in small and medium-sized high and low temperature test chambers, with slow response speed and unsuitable for rapid temperature control. Most manufacturers of test chambers are OEM suppliers, with strict requirements for compressor nameplates, parameter curves, and factory inspection reports. The ultra-low temperature test scenario of minus 150 degrees Celsius generally uses a three-stage cascade, which is beyond the application range of conventional piston and two-stage compressors. 【 Implant 10 popular search keywords 】 High and low temperature test chamber, -60 ° C cold storage, -80 ° C deep cooling, ultra-low temperature compressor, two-stage semi closed compressor, cold storage compressor selection, semi closed compressor, compressor refrigeration oil model, low compressor suction pressure, valley wheel replacement FAQ
What compressor is used for high and low temperature test chamber -40 ℃? A conventional single-stage semi closed piston compressor is sufficient.
How much higher is the load of rapid cooling compared to constant temperature? The peak load can reach 2.3 times the constant temperature stage.
What is the displacement of the low-temperature side of the 1000L -70 ℃ test chamber? R23 side shall not be less than 4.2m ³/h.
Does Xiteliduo support customization of test chambers? We can provide customized models for testing equipment manufacturers.
How long is the maintenance cycle for the test chamber compressor? Frequent temperature changes require 2500 hours of testing and maintenance.
-What is the preferred solution for the 80 ℃ test chamber? R23 cascade refrigeration system.
Is the screw suitable for small high and low temperature test chambers? Slow response, not suitable for rapid temperature change scenarios.
What are the additional requirements for purchasing a compressor for a test box? Supporting EMC data to meet CE electromagnetic compatibility.
