【Q&A Question 326】December 10, 2017
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【Q&A Question 326】December 10, 2017: Briefly explain how the compression ratio of a reciprocating compressor affects its operation List at least three answers: ① An excessive compression ratio can cause the temperature at the compressor outlet to rise too high, leading to a decrease in the viscosity of the lubricating oil, coking, and softening of the packing ； ②The relative volume of the cylinder decreases, and as the high-pressure residual gas inside the cylinder expands, the volume it occupies increases relatively ； ③It consumes more power compared to multi-stage compressors under the same pressure ； ④The crankshaft load experiences large fluctuations frequently, resulting in significant vibration ； ⑤If the compression ratio is too low, it increases the number of compression cycles and makes the structure more complex. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) For management purposes, if you need to view content from a few days ago, please go through the summary post below. 2017 Q&A Summary Thread (updates starting now) https://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates starting now) https://bbs.hcbbs.com/thread-1657794-1-1.html 2017 Daily Image Summary Thread https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1875160 2017 LNG Version Daily Question Catalog https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1804162 2016 Q&A Summary Thread (updates completed) https://bbs.hcbbs.com/thread-1597792-1-1.html
1. This leads to a decrease in volumetric efficiency; when it drops to a certain level, the compressor’s gas delivery coefficient becomes 0, and the compressor can hardly draw in refrigerant vapor, thereby losing its cooling capacity. 2. It causes the actual compression process to deviate more from the ideal condition, resulting in increased actual power consumption of the refrigeration compressor, reduced efficiency, and a lower coefficient of performance. 3. This inevitably leads to an increase in the exhaust temperature of the refrigeration compressor, sometimes even exceeding the allowable limit for that temperature. At the same time, excessively high exhaust temperature can also affect the proper operation of the refrigeration cycle.
1. An excessive compression ratio leads to a decrease in the volume coefficient, resulting in reduced efficiency. 2. An excessive compression ratio causes an increase in temperature during the compression process, leading to excessively high exhaust temperatures. 3. An excessive compression ratio results in an increase in power output
1. Increasing the compression ratio can reduce energy consumption. 2. The higher the compression ratio, the higher pressure can be achieved at a constant inlet pressure. 3. If the intake pressure remains constant and the exhaust pressure decreases, the compression ratio drops, the displacement coefficient increases, thereby increasing the exhaust volume.
①An excessively high compression ratio can cause the compressor’s terminal temperature to rise, leading to a decrease in the viscosity of the lubricating oil, coking, and softening of the packing； ②The relative volume of the cylinder decreases, and as the high-pressure residual gas inside the cylinder expands, the volume it occupies increases relatively ； ③It consumes more power compared to multi-stage compressors under the same pressure ； ④The crankshaft load experiences large fluctuations frequently, resulting in significant vibration ； ⑤If the compression ratio is too low, it increases the number of compression cycles and makes the structure more complex.
1. This leads to a decrease in volumetric efficiency; when it drops to a certain level, the compressor’s gas delivery coefficient becomes 0, and the compressor can hardly draw in refrigerant vapor, thereby losing its cooling capacity. 2. It causes the actual compression process to deviate more from the ideal condition, resulting in increased actual power consumption of the refrigeration compressor, reduced efficiency, and a lower coefficient of performance. 3. This inevitably leads to an increase in the exhaust temperature of the refrigeration compressor, sometimes even exceeding the allowable limit for that temperature. At the same time, excessively high exhaust temperature can also affect the proper operation of the refrigeration cycle.
①An excessively high compression ratio can cause the compressor’s terminal temperature to rise, leading to a decrease in the viscosity of the lubricating oil, coking, and softening of the packing； ②The relative volume of the cylinder decreases, and as the high-pressure residual gas inside the cylinder expands, the volume it occupies increases relatively ； ③It consumes more power compared to multi-stage compressors under the same pressure ； ④The crankshaft load experiences large fluctuations frequently, resulting in significant vibration
Affecting exhaust pressure； Exhaust temperature ； Export traffic, etc
Impact on pressure, exhaust temperature, operating load, hydrogen flow rate
High exhaust temperature and pressure, resulting in increased compressor load