[Mechanical Equipment Technology Edition] Daily Question 201807010: Refrigeration Systems — Refrigeration Parameters (19)
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This year, the 【One Question per Day】 series is divided into three categories: screw refrigeration compressors, refrigeration systems, and oil circuits, aiming to provide a comprehensive understanding of refrigeration technology. (If you encounter something you don’t know or can’t answer, please actively look up information; by doing so, your skills will improve!) ) All participants in the comments on this post will receive 1-3 wealth points; those who give complete answers will get 10-15 points, with the validity period being two days. Refrigeration system – refrigeration parameters (19): Regarding the temperature discussed in the previous section, let me give an example. Without considering external factors, there are two objects, A and B; the temperature of object A is 10 degrees, while that of object B is 20 degrees. When these two objects come into contact, the temperature of object A will rise, while the temperature of object B will drop. Eventually, both objects will reach a temperature of 15 degrees. If a copper tube is placed between A and B, will A and B still reach 15 degrees? It’s obvious which is larger, A or B. So, can the heat exchange efficiency of this copper pipe be represented by B—A? The same problem can be approached from a different perspective, which will make things clearer in the mind. ============================== High-quality promotions: Mechanical equipment——Videos on the repair and adjustment of York compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mechanical equipment——Maintenance procedures for York screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mechanical equipment——Upgrading of York Quinton control centers https://bbs.hcbbs.com/thread-1804837-1-1.html Mechanical equipment——Major repairs of GEA Grasox screw compressors https://bbs.hcbbs.com/thread-1800467-1-1.html Mechanical equipment——Disassembly and maintenance of British HOWDEN screw compressors https://bbs.hcbbs.com/thread-1832529-1-1.html Mechanical equipment——Disassembly and maintenance of Japanese Maekawa MYCOM screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=
If a copper tube is added between A and B, then A and B will not reach 15 degrees. The temperature of A is low while the temperature of B is high.
This post was last edited by “Hasty Passerby” on July 11, 2018, at 10:26. In a condenser, the cooling water acts as A, while the refrigerant acts as B. Heat is transferred from B to A. Since there is a copper pipe wall in between them, the temperature of B can never be lower than that of A; in other words, the temperature of the refrigerant cannot be lower than that of the cooling water. Equivalently, the temperature of the cooling water cannot exceed that of the refrigerant. (After cooling, or when the temperature of the cooling water does not exceed the saturation temperature of the refrigerant; only when the temperature of the refrigerant is below or equal to its saturation temperature can it change from a gaseous state to a liquid state, thereby achieving condensation.)
In the condenser, the cooling water corresponds to A, while the refrigerant corresponds to B. Heat is transferred from B to A; however, due to the copper tube wall separating them, the temperature of B will never be lower than that of A. In other words, the temperature of the refrigerant will not be lower than that of the cooling water, which means that the temperature of the cooling water will not be higher than that of the refrigerant.
OP, could you explain the meaning of the minimum temperature difference? ?
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