当前位置: Home / Faq / Biogas purification FAQ /

Changes in entropy and enthalpy after throttling and expansion

Changes in entropy and enthalpy after throttling and expansion
Sep 05, 2025
Author: DEAR AST

Throttling and expansion are two commonly used methods for generating cooling capacity. The throttling process generally involves a sudden decrease in the flow area of gas through the throttle valve, causing a pressure drop due to gas disturbance. Due to the short time, there is no heat exchange with the outside world, and the enthalpy value of the gas remains unchanged. The throttling process is irreversible, resulting in an increase in entropy. Expansion is the work done by the gas, and the enthalpy of the gas decreases. Ideally, this is a reversible process, so the entropy value of the expansion process remains unchanged.

Since its inception, Kaifeng DEAR Air Separation Industrial Co., Ltd. has manufactured hundreds of high-quality air separation equipment for multiple enterprises in the air separation equipment manufacturing industry, with product grades including large air separation, medium air separation, and small air separation; Product varieties include oxygen nitrogen equipment, oxygen production equipment, high-purity nitrogen, and liquefaction equipment; The process flow includes various air separation equipment such as two-stage distillation low-pressure process, multi-stage distillation hydrogen free argon production, single-stage distillation high-purity nitrogen, two-stage distillation high-purity nitrogen, low-purity gas oxygen liquid oxygen, and full extraction. The product users involve metal smelting, metal materials, petrochemical industry, coal processing, electronics industry, new energy, environmental protection, renewable energy, and so on.

DEAR Air Separation Solve YourChanges in entropy and enthalpy after throttling and expansionYou can also learn about otherBiogas purification FAQ about DEAR Air Separation, and solve the problem for you.
Didn’t find the problem encountered?
Please contact live chat or email for quick help.
Related FAQ
More Related FAQ
The main heat exchanger is the key equipment to ensure the performance of the air separation plant. Its functions in the air separation plant of the molecular sieve pre-filtration process are as follows: recover the cooling capacity of the reflux gas, ensure that the heat exchange temperature difference is within the design range; provide sufficient expansion gas in front of the expander to make up for the cooling loss of the air separation plant; provide raw air for the lower tower under the design conditions; and the working medium is in the main heat exchanger The resistance value in meets the process requirements.
2025.12.31
A low pressure nitrogen expander is added to the process design. The pressure nitrogen from the pressure tower and high pressure expander is expanded into low pressure nitrogen, which is combined with the nitrogen coming from the low pressure tower and fed into the charge gas compressor. This is specially set up for rapid oxygen load changes. The oxygen product flow rate during normal operation corresponds to the amount of oxygen contained in the amount of air entering the air separation unit. T...
2025.12.30
Need more information?
Contact us for more details about our air separation equipment, solutions and services.
Products
  • Large air separation
  • Small air separation
  • High purity nitrogen air separation
  • Liquefaction air separation
  • Complete air separation
  • Biogas purification
  • Air separation parts
Need more information?
Tel:+86-19837850537
© Kaifeng DEAR Air Separation Industry Co., Ltd.. All rights reserved.
Online
Inquiry
Email
Top