【Mechanical Equipment Technology Edition】Daily Question 201806015: Refrigeration Systems — Study of Pressure-Humidity Diagrams of Refrigeration Parameters* (8)
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This post was last edited by YORK Industrial Refrigeration on 2018-6-19 at 10:08. 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 commenters on this post will be rewarded with 1-3 wealth points; those who provide accurate answers will receive 10-15 points, with the reward valid for two days. ============================== Refrigeration Systems—Pressure-Enthalpy Diagrams of Refrigeration Parameters* (8): The diagram below shows the pressure-enthalpy diagram of a theoretical refrigeration cycle. Please explain the processes in the refrigeration cycles represented by 4-1, 1-2, 2-3, and 3-4 respectively. Evaporation, compression, condensation, throttling ============================== 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 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 Mycom screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=
This post was last edited by Hasty Passer on June 15, 2018, at 17:35. Based on the learning materials downloaded yesterday and in accordance with the description in the “Diagram of the theoretical thermodynamic characteristics of an ideal refrigeration cycle (without subcooling or superheating)”, it can be seen that: 1. Process 4-1 is an isobaric heat absorption and constant-temperature vaporization process – corresponding to evaporation under actual operating conditions. 2. Process 1-2 is an isentropic compression thermodynamic process – corresponding to compression under actual operating conditions. 3. Process 2-3 should be divided into two segments; let the unnamed intersection point between line 2-3 and the isobaric line be denoted as 2”. Then, process 2-2” represents an isobaric heat release and temperature reduction/cooling process； 2”-3 represents a isobaric and isothermal exothermic liquefaction process. Combined, should 2-3 be: an isobaric exothermic cooling and liquefaction process----------------------------------which corresponds to the actual condition of condensation? 4, 3-4 is an isenthalpic adiabatic pressure reduction process----------which corresponds to the actual condition of throttling. Thank you for your guidance!
4-1 Isobaric endothermic constant-temperature vaporization process 1-2 Adiabatic compression thermodynamic process 2-3 Isobaric exothermic cooling process and isobaric exothermic constant-temperature liquefaction process 3-4 Isenthalpic adiabatic depressurization process
It can be directly described as compression, condensation, throttling, evaporation
4-1, Transformation of liquid into gas (vaporization process)； 1-2, Pressure increase process (compression process) ； 2-3, the process of gas transforming into liquid (liquefaction process) ； 3-4, the process of pressure reduction, (throttling process)
1‑2 compression, 2‑3 condensation, 3‑4 throttling, 4‑1 evaporation
Based on the learning materials downloaded yesterday, and in conjunction with the explanations provided in the \"Theoretical thermodynamic characteristic process diagram of an ideal refrigeration cycle (without subcooling or superheating)\\", it can be seen that: 1. Stage 4-1 is a constant-pressure heat absorption and isothermal vaporization process – corresponding to the actual operation of evaporation. 2. Stage 1-2 is a isentropic compression process – corresponding to the actual operation of compression. 3. Stage 2-3 should be divided into two segments; let the unnamed intersection of stage 2-3 with the constant-volume line be denoted as 2\"; then stage 2-2\" is a constant-pressure heat release and cooling process； 2”-3 represents a isobaric and isothermal exothermic liquefaction process. Combined, should 2-3 represent a process of isobaric heat release, cooling, and liquefaction? -- This corresponds to the actual condition of condensation. 4, 3-4 represents an isenthalpic adiabatic pressure reduction process -- which corresponds to the actual condition of throttling
4-1 Isobaric endothermic isothermal vaporization process ； 1-2 Isentropic compression thermodynamic process ； 2-3 Isobaric exothermic cooling process and isobaric exothermic constant-temperature liquefaction process ； 3-4 Isenthalpic adiabatic pressure reduction process.
Evaporation, compression, condensation, expansion