Can the expanders used in cryogenic applications be used in other places where cooling is required?
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Can the expanders used in cryogenic applications be used in other places where cooling is required? Could that expert have information on this topic?
No need; using throttling for everything else will suffice
Reply 2# The goal is to replace the refrigerator; we want to see if it’s feasible!
It’s not feasible; the two principles are different. Moreover, expanders are complicated, with high requirements regarding the pressure and temperature of the incoming gas. Refrigerators, on the other hand, use refrigerants, which makes them simpler and more convenient to use
Reply to 4# 525h: Is there a solid economic analysis available? Regarding expanders, I think the main issues are: 1) a certain pressure needs to be supplied from outside, and 2) high requirements are placed on the quality of the air. However, I don’t have any information on this topic, especially no data related to economic analysis. If any of you colleagues have such information, please feel free to share it. If economic analysis is feasible, I think this is a great topic. 1. Avoid the use of refrigerants, especially ammonia or Freon, as these are harmful to human health. 2. The temperature required in actual use does not need to be as low as minus 100 degrees, as in cryogenic applications; generally, a temperature of minus 40 degrees is sufficient to meet ordinary needs, thus eliminating the need for extremely strict insulation measures. Please ask experts to discuss this!
I found this in a military-related article; it seems to be related to our expansion-based refrigeration mechanism. “A power adapter is, in essence, a motor and a generator combined. The 136V input from the generator is converted into 6 different voltages. There are also some small ones. 32V and 150V are for gyroscopes. The air conditioning turbine of the J7 is responsible for oxygen production, pressure regulation, and cooling of the equipment compartment. High-pressure air at 120 degrees and 1 MPA is supplied from the high-pressure stage of the engine; after passing through this turbine, the pressure is reduced to 1 atmosphere and the temperature drops to 0 degrees. This thing rotates at over 100,000 revolutions per minute, and it needs to be replaced every 15 hours. ” J7 refers to our country’s J-7 fighter aircraft.
Reply to 6# wbzzip: Haha, the turbine expanders I’ve seen have speeds of 120,000 revolutions per minute as well as 34,000 revolutions per minute, but I’ve never heard of any of them dying after operating for 12 hours. An expander primarily requires high-pressure air, but this pressure is relative – compressed air at 6 kilograms per square centimeter can be used, as can that at 13 kilograms per square centimeter. What’s important is to conduct an economic analysis of the cost structure involving the air compressor, filter, expander, and the refrigeration unit that generates cold energy. The air compressor needs electricity to operate, while the electricity required for the expander is mainly used in the oil station. The filter functions as a valve. From a practical standpoint, if high-pressure air is available, then an expander can certainly be used. For units capable of operating at -35 degrees Celsius, a unit with a capacity of 710,000 kcal costs around 1 million yuan; however, the cost of the expander itself is likely only around 200,000 yuan. The operating costs are also low – an air compressor with a capacity of 8 kilograms per square centimeter and 42 cubic feet per minute costs around 300,000 yuan. Adding in the cost of the filter, this setup seems to have good operational value.
The engine life of the home-use bean-stamping machine we use is only 900 hours.