What is the enthalpy of R134a?
What is the enthalpy of R134a?
Thermodynamic Properties of Saturated Refrigerant R134a
| Pressure | Temperature | Enthalpy (kJ/kg) |
|---|---|---|
| 1200 | 46.3 | 117.8 |
| 1400 | 52.4 | 127.3 |
| 1600 | 57.9 | 136.0 |
| 1800 | 62.9 | 144.1 |
What pressure should a 134a run at?
22 pounds per square inch
For normal running pressures in the R134a system, at the lowest temperature, the coil should run at 22 pounds per square inch that is 45-20, 25 degrees Fahrenheit. While at the highest temperature it should be 57 pounds per square inches that is 60-20,40 degrees Fahrenheit.
What is pressure enthalpy chart?
The pressure-enthalpy diagram (log P/h diagram) is a very useful tool for refrigerant technicians. The area below the saturation lines for liquid and gas (A-CP-B in Figure 2.1) represents the conditions where the refrigerant can change its state of aggregation from liquid to gas or vice versa.
How do you find the enthalpy of R134a?
You can compute specific enthalpy “h” from the specific internal energy “u”, pressure “p”, and specific volume “v”:
- >> u_sat_v = interp1( r134aPropertyTables.p, r134aPropertyTables.vapor.u_sat, p)
- >> v_sat_v = interp2( r134aPropertyTables.p, r134aPropertyTables.vapor.unorm, r134aPropertyTables.vapor.v, p, 1)
What should the high and low side pressures be?
The system should be about 25 to 30 psi on the low side and 200 to 250 psi on the high side. If the ambient temperature is higher or lower than normal (70 to 80°F) the pressures will go up or down accordingly.
Do you charge 134a as a vapor or liquid?
You can fill it through the high side port by liquid. Engine off. Takes about 10 seconds to empty a can vs 10 minutes by hooking into the low side port and charging with gas.
Which chart is most useful in refrigeration?
Fahrenheit scale
There are two temperature scales that anyone in refrigeration work should understand. They are the Fahrenheit scale and the Celsius (formerly Centigrade) scale. The Fahrenheit scale is the most commonly used in the United States.
Which is the bubble on the pressure enthalpy chart?
The pressure-enthalpy chart, as shown in Fig. 2, displays all the pertinent properties for a given refrigerant (in this example R22). The bubble to the left is the portion of the diagram where the refrigerant is in the saturated condition.
How to calculate nitrogen in thermodynamic state?
Calculation of thermodynamic state variables of nitrogen in saturation state, boiling curve Lower limit for calculation: -210 C, 0.13 bar bar upper limit: -148 C, 33 bar. Pressure: barMillibarMPak PaPascalN / mm2kp / cm2 (atü)lb / feet2psi (lb / inch2)Torr (mm Hg)inch Hgmm H2Oinch H2Ofeet H2O
Which is the correct pressure for nitrogen N2?
Pressure: barMillibarMPak PaPascalN / mm2kp / cm2 (atü)lb / feet2psi (lb / inch2)Torr (mm Hg)inch Hgmm H2Oinch H2Ofeet H2O Temperature: CelsiusKelvinFahrenheit Calculation of thermodynamic state variables of nitrogen in saturation state, boiling curve Lower limit for calculation: -210 C, 0.13 bar bar upper limit: -148 C, 33 bar. Pressure:
Why is the Pres sure enthalpy chart important?
In an effort to gain a better understanding of the various heat transfer processes occurring in a refrigeration system, the pres- sure-enthalpy chart can be of great use. Additionally, once understood, the chart can be a tremendous benefit in analyz- ing the relative health of a refrigeration system.
https://www.youtube.com/watch?v=xteSowq_Ebs