What do the three air conditioning pressures mean?
DATE:2024-09-13
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The three pressures of the air conditioning system are: air conditioning balance pressure; air conditioning high pressure; air conditioning low pressure;
These three pressures are important parameters for air conditioning maintenance, the three pressures are the pressure corresponding to the refrigerant R22 circulating in different positions in the air conditioning pipeline, because R22 is circulating between the gas-liquid cycle of change, accompanied by heat absorption and exothermic, so the temperature of the external environment has a significant impact on it. Generally speaking, when the ambient temperature is high, the pressure value becomes larger. When the ambient temperature is low, the pressure value becomes smaller.
Equilibrium pressure refers to the pressure of high and low pressure balance when the compressor is not working; high pressure refers to the exhaust pressure or condensing pressure; low pressure refers to the suction pressure or evaporating pressure.
The measurement of the three pressures are in the outdoor unit valve on the process port, refrigeration operation for the low-pressure pressure, heating operation for the high-pressure pressure, does not work for the equilibrium pressure.
Refrigeration evaporation refers to boiling, so the evaporation temperature is the boiling point, condensation refers to a certain pressure of R22 in the saturated state of gas to liquid process, so the condensation temperature is also the boiling point. R22 at different pressures corresponds to a different boiling point, evaporation pressure and evaporation temperature of the one-to-one correspondence.
Refrigeration air conditioning refrigeration design conditions are outdoor ring temperature of 35 ℃, indoor temperature of 27 degrees, evaporative temperature +5 ℃, evaporative pressure of 0.48MPa, so the air conditioning standard refrigeration low pressure of 0.48MPa. air conditioning refrigeration piping design relative pressure (gauge pressure) refrigeration state of the low-pressure pressure is the equilibrium pressure of half, so the equilibrium pressure of 0.96MPa. in order to achieve the ideal cooling In order to achieve the ideal heat dissipation effect, refrigeration design using air condensing, condensing standard temperature difference is selected 15 ℃, so in the outdoor 35 ℃ condensing temperature of 50 ℃, 50 ℃ corresponding to the pressure value of 1.83Mpa, so the air-conditioning high-pressure pressure of 1.83MPa.
Refrigeration pressure refers to the physics of the pressure, the unit of pressure and “kg/cm2”, which is what we call “kilograms of pressure.
1kg/cm2 ≈ 0.098MPa ≈ 0.1MPa; so the size of the three pressures is “4.8kg”, “9.6kg”, “18.2kg”.
Due to the air conditioning working environment usually can not meet the working conditions, as well as the impact of humidity, so the summer cooling state of the three pressure values are: low pressure 0.5MPa or 5 kg; high pressure 1.8MPa or 18 kg; balance pressure 1MPa or 10 kg. Air conditioning in the winter heating environment and refrigeration conditions are too different, the external ambient temperature is low, so the three pressures will have a large change in the air conditioning environment to use the lower limit temperature 5 ℃ as a reference for research and analysis.
In order to achieve the ideal evaporation heat absorption effect, refrigeration design air as a cold-carrying material, evaporation standard temperature difference selected 10 ℃, so the evaporation temperature should be -5 ℃, the corresponding pressure of 0.32 MPa.
As the outdoor unit environment for 5 ℃, its optimal evaporation temperature of -5 ℃, while the outside coil frost is generally around -6 ℃, so the colder the winter heating effect is worse, in order to maximize the absorption of heat at low temperatures, through the heating auxiliary capillary tube to reduce the evaporative pressure, thereby reducing the evaporative temperature, therefore, the cooling state of the low-pressure no longer balance the pressure of the general, but rather a little smaller, so the heating balance pressure About 0.7MPa.
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These three pressures are important parameters for air conditioning maintenance, the three pressures are the pressure corresponding to the refrigerant R22 circulating in different positions in the air conditioning pipeline, because R22 is circulating between the gas-liquid cycle of change, accompanied by heat absorption and exothermic, so the temperature of the external environment has a significant impact on it. Generally speaking, when the ambient temperature is high, the pressure value becomes larger. When the ambient temperature is low, the pressure value becomes smaller.
Equilibrium pressure refers to the pressure of high and low pressure balance when the compressor is not working; high pressure refers to the exhaust pressure or condensing pressure; low pressure refers to the suction pressure or evaporating pressure.
The measurement of the three pressures are in the outdoor unit valve on the process port, refrigeration operation for the low-pressure pressure, heating operation for the high-pressure pressure, does not work for the equilibrium pressure.
Refrigeration evaporation refers to boiling, so the evaporation temperature is the boiling point, condensation refers to a certain pressure of R22 in the saturated state of gas to liquid process, so the condensation temperature is also the boiling point. R22 at different pressures corresponds to a different boiling point, evaporation pressure and evaporation temperature of the one-to-one correspondence.
Refrigeration air conditioning refrigeration design conditions are outdoor ring temperature of 35 ℃, indoor temperature of 27 degrees, evaporative temperature +5 ℃, evaporative pressure of 0.48MPa, so the air conditioning standard refrigeration low pressure of 0.48MPa. air conditioning refrigeration piping design relative pressure (gauge pressure) refrigeration state of the low-pressure pressure is the equilibrium pressure of half, so the equilibrium pressure of 0.96MPa. in order to achieve the ideal cooling In order to achieve the ideal heat dissipation effect, refrigeration design using air condensing, condensing standard temperature difference is selected 15 ℃, so in the outdoor 35 ℃ condensing temperature of 50 ℃, 50 ℃ corresponding to the pressure value of 1.83Mpa, so the air-conditioning high-pressure pressure of 1.83MPa.
Refrigeration pressure refers to the physics of the pressure, the unit of pressure and “kg/cm2”, which is what we call “kilograms of pressure.
1kg/cm2 ≈ 0.098MPa ≈ 0.1MPa; so the size of the three pressures is “4.8kg”, “9.6kg”, “18.2kg”.
Due to the air conditioning working environment usually can not meet the working conditions, as well as the impact of humidity, so the summer cooling state of the three pressure values are: low pressure 0.5MPa or 5 kg; high pressure 1.8MPa or 18 kg; balance pressure 1MPa or 10 kg. Air conditioning in the winter heating environment and refrigeration conditions are too different, the external ambient temperature is low, so the three pressures will have a large change in the air conditioning environment to use the lower limit temperature 5 ℃ as a reference for research and analysis.
In order to achieve the ideal evaporation heat absorption effect, refrigeration design air as a cold-carrying material, evaporation standard temperature difference selected 10 ℃, so the evaporation temperature should be -5 ℃, the corresponding pressure of 0.32 MPa.
As the outdoor unit environment for 5 ℃, its optimal evaporation temperature of -5 ℃, while the outside coil frost is generally around -6 ℃, so the colder the winter heating effect is worse, in order to maximize the absorption of heat at low temperatures, through the heating auxiliary capillary tube to reduce the evaporative pressure, thereby reducing the evaporative temperature, therefore, the cooling state of the low-pressure no longer balance the pressure of the general, but rather a little smaller, so the heating balance pressure About 0.7MPa.