Why cannot the exhaust temperature of nitrogen as the working medium in reciprocating compressors exceed 150
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Why cannot the exhaust temperature of nitrogen as the working medium in reciprocating compressors exceed 150 degrees?
The theoretical exhaust temperature will exceed 150°C, requiring additional cooling. No overheating issue: Conclusion and recommendations – The compressor should operate normally within its specified range of use, without occurrences of high motor temperature or excessively high exhaust gas temperature, etc., as signs of overheating. Compressor overheating is an important fault indicator, suggesting serious problems with the refrigeration system or improper use and maintenance of the compressor.
Your question isn’t clear enough; I’m not sure if my answer will be reasonable. You are referring to piston rings made of PTFE material, which have specific temperature requirements. For this reason, this temperature must not be exceeded. The design of this temperature is also related to the fact that the structure of the machine should not be overly affected by temperature changes.
High temperatures have an impact on the lubricating oil in the cylinder as well as on the piston rings, and they also result in increased energy consumption.
I see that the standards specify that hydrogen exhaust must not exceed 135, and nitrogen exhaust must not exceed 150. What is the reason for such regulations?
There are many such factors; when using the same equipment for gases in different media, there is much that needs to be verified. For example, different media have different physical and chemical properties. There are strict requirements regarding which gases are suitable for use with a particular device; not any gas can be compressed simply because it is a compressor. Nitrogen is an inert gas, so it does not place high demands on equipment. However, specialized equipment is required for hydrogen, oxygen, and other flammable, explosive, toxic, harmful, or corrosive gases. It is incomparable and meaningless to consider the characteristics of each device individually. It is recommended that learning should be targeted.
Once the temperature reaches a certain level, the energy consumption increases significantly; you can look into this. For the same reason as why the compression ratio of reciprocating machines cannot be too high
In fact, exhaust temperature is one of the important performance indicators for evaluating reciprocating machines. The lower the exhaust temperature, the better. Limits on exhaust temperature are imposed in some cases to prevent explosions caused by high-temperature gases (such as ethylene and acetylene), in other cases to prevent corrosion (such as oxygen and chlorine), and in yet other cases to prevent gas polymerization and coking (such as petroleum gas). There are also cases where such limits are due to mechanical and material constraints (in the case of oil lubrication, it is necessary to prevent the lubricant from coking as well)