【Mechanical Equipment Technology Edition】Daily Question 20180606: Refrigeration Systems — Refrigeration Parameters (4)
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This post was last edited by YORK Industrial Refrigeration on 2018-6-11 at 10:05. This year’s 【Daily Question】 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; as you do 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 (4): If there is suction superheat, what is exhaust superheat? What is its purpose? Exhaust superheat: The difference between the exhaust temperature and the condensation temperature. Similar to suction superheat, exhaust superheat can indicate the condition of liquid supply to the equipment (whether it is overfilled with liquid or lacks sufficient refrigerant). When exhaust superheat is below normal levels, the equipment is likely to be overfilled with liquid; when it is above normal levels, there is insufficient liquid supply or insufficient refrigerant in the equipment. ============================== Premium promotions: Mechanical equipment – Videos on the repair and adjustment of York compressors: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mechanical equipment – Procedures for maintaining York screw compressors: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mechanical equipment – Upgrading York Quinton control centers: https://bbs.hcbbs.com/thread-1804837-1-1.html Mechanical equipment – Major repairs of GEA Grasso 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 MYCOM screw compressors: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=
The superheat of a refrigeration machine is generally divided into two types: exhaust superheat and suction superheat； The exhaust superheat is equal to the exhaust temperature minus the saturation temperature corresponding to the exhaust pressure; this superheat ensures that the exhaust gas from the compressor in the high-pressure chamber does not liquefy there, thereby preventing the refrigeration oil from being diluted ； Suction superheat is equal to the suction temperature minus the saturation temperature corresponding to the suction pressure. The presence of suction superheat ensures that no liquid refrigerant returns to the compressor, thereby preventing liquid slugging in the compressor. Excessively high exhaust superheat can reduce the lubricating effect of the oil; if the exhaust temperature is too high, it can cause carbonization of the oil, leading to poor lubrication and severe wear of the compressor ； If the exhaust temperature is too low, the concentration of the lubricating oil decreases, which may lead to backflow of liquid in the system; fluid shock can cause the compressor’s vortex disc to break.
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. Excessively high exhaust superheat can reduce the lubricating effect of the oil; if the exhaust temperature is too high, it can cause carbonization of the oil, leading to poor lubrication and severe wear of the compressor ； If the exhaust temperature is too low, the concentration of the lubricating oil decreases, which may lead to backflow of liquid in the system; such liquid shock can cause the compressor to break.
1. Definition: Exhaust superheat is the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. 2. Function: The presence of exhaust superheat ensures that the exhaust gas from the compressor in the high-pressure chamber does not liquefy there, thereby preventing the refrigeration oil from being diluted； 3. Effects of excessively high or low temperatures: Excessively high exhaust superheat can reduce the lubricating effect of the oil; very high exhaust temperatures can cause carbonization of the oil, poor lubrication, and severe wear on the compressor ； If the exhaust temperature is too low, the concentration of the lubricating oil decreases, which may lead to backflow of liquid in the system; fluid shock can then cause damage to the compressor. It doesn’t seem sufficient yet; I’ll keep looking for more information to supplement it.
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. In other words, superheat refers to the number of degrees by which the actual temperature of the working fluid is higher than the saturation temperature corresponding to its actual pressure. Superheat = suction temperature of the compressor – evaporation temperature of the refrigerant in the evaporator. A certain level of superheat is necessary to ensure that the refrigerant entering the compressor is free of liquid, thereby preventing wet strokes.
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure; this is done to ensure that the refrigerant is in a liquid state during throttling and evaporation, thereby enabling heat exchange
Exhaust superheat is the temperature difference between the temperature of the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. Superheat = suction temperature of the compressor – evaporation temperature of the refrigerant in the evaporator. A certain level of superheat is necessary to ensure that the refrigerant entering the compressor is free of liquid, thereby preventing wet strokes. The presence of exhaust superheat ensures that the compressor exhaust in the high-pressure chamber does not liquefy there, thereby preventing the refrigeration oil from being diluted. Excessively high exhaust superheat can reduce the lubricating effect of the oil; if the exhaust temperature is too high, it can cause carbonization of the oil, leading to poor lubrication and severe wear of the compressor ； If the exhaust temperature is too low, the concentration of the lubricating oil decreases, which may lead to backflow of liquid in the system; fluid shock can cause the compressor’s vortex disc to break.
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. Excessively high exhaust superheat can reduce the lubricating effect of the oil; if the exhaust temperature is too high, it can cause carbonization of the oil, leading to poor lubrication and severe wear of the compressor ； If the exhaust temperature is too low, the concentration of the lubricating oil decreases, which may lead to backflow of liquid in the system; such liquid shock can cause the compressor to break.
The superheat of a refrigeration machine is generally divided into two types: exhaust superheat and suction superheat； The exhaust superheat is equal to the exhaust temperature minus the saturation temperature corresponding to the exhaust pressure; this superheat ensures that the exhaust gas from the compressor in the high-pressure chamber does not liquefy there, thereby preventing the refrigeration oil from being diluted ； Suction superheat is equal to the suction temperature minus the saturation temperature corresponding to the suction pressure. The presence of suction superheat ensures that no liquid refrigerant returns to the compressor, thereby preventing liquid slugging in the compressor. Excessively high exhaust superheat can reduce the lubricating effect of the oil; if the exhaust temperature is too high, it can cause carbonization of the oil, leading to poor lubrication and severe wear of the compressor ； If the exhaust temperature is too low, the concentration of the lubricating oil decreases, which may lead to backflow of liquid in the system; fluid shock can cause the compressor’s vortex disc to break.
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. Excessively high exhaust superheat can reduce the lubricating effect of the oil; if the exhaust temperature is too high, it can cause carbonization of the oil, leading to poor lubrication and severe wear of the compressor ； If the exhaust temperature is too low, the concentration of the lubricating oil decreases, which may lead to backflow of liquid in the system; such liquid shock can cause the compressor to break.
The exhaust superheat is equal to the exhaust temperature minus the saturation temperature corresponding to the exhaust pressure; this superheat ensures that the exhaust gas from the compressor in the high-pressure chamber does not liquefy there, thereby preventing the refrigeration oil from being diluted