1 basic knowledge
1. 1 gasification: evaporation and boiling (heated)
1. 2 liquefied: cooling/condensed, compressed volume (heated gurus)
1. 3 boiling point/saturation temperature: osteoporosis of liquid osteoporosis (synthesis to thiophosate)
1. 4 critical temperature: is the maximum temperature at which the substance can maintain the liquid state under pressure. Beyond this temperature, no matter how much pressure is exerted, the substance cannot be liquefied and can only exist in gaseous form。
1. 5 critical pressure: the saturation pressure at the critical temperature is beyond which the refrigerant is not liquid regardless of the temperature increase。
1. 6 refrigerant properties: evaporation and condensation; potential heat (where a unit mass refrigerant can transport more heat); critical temperatures need to be higher than ambient temperatures to ensure condensation at constant temperatures。
1. 7 static pressure: system pressure when the refrigeration system is completely suspended and balanced with ambient temperature. Temperature in the environment, altitude, system charge, etc. Will change static pressure。
1. 8 absolute pressure = surface pressure + atmospheric pressure (1bar)
2 refrigeration principles (example r410a)
2. 1 compressors: temperature increase
Process: inhalation of low-temperature low-pressure gas refrigerants and compression of their pressure, temperature, etc。
Pressure: low pressure side 0. 6 mpa (boiling point approximately -10°c)
Pressure: high pressure side 2. 6 mpa (approximately 45°c boiling point)
Temperature: from 5° to 120°c (well above critical temperature 72. 8°c)。
Consistency: overheated gas at a much higher temperature than the boiling point。
Energy conversion: electro-mechanical capacity increases within refrigerants。
2. 2 condensers: hydrothermal fluidization
Process: graduation of high-temperature high-pressure gas refrigerants in condensers through dissipation (pan or water cooling)。
Pressure: constant at 2. 6 mpa。
Temperature change: from gaseous temperature (e. G. 120°c) to liquid temperature (e. G. 45°c)。
Conformity: mixing of gaseous fluids to full liquid。
• heat transfer: release of heat into the outdoor environment (including two-phase submersible heat and heat converted by compressors)。
2. 3 throttles: pressure-relief
Activation: high pressure liquid refrigerants drop through the throttle valve, expand in volume, and the temperature drops sharply。
• rationale: joule-tomson effect (insulation leads to lower temperature)。
Pressure: from 2. 6 mpa to 0. 6 mpa。
Temperature: from 45°c to -10°c (corresponding to boiling point -10°c under 0. 6 mpa)。
Phase: liquid-gas mixture
2. 4 evaporaters: heat gasification
Process: low-temperature low-pressure liquid refrigerants enter evaporation units (indoor machines) and absorb thermal vapour of the environment。
Pressure: constant at 0. 6 mpa
Temperature: -10°c to 5°c
Consistency: low pressure gas
• thermal transport: cooling by absorbing indoor heat。
3 common refrigerant temperature and pressure control table (for information)
