What is the enthalpy of R134a?
148.4 kJ/kg
In the conversion equation below, H (ref) and S (ref) are the saturated liquid enthalpy and entropy at –40 °C. For HFC-134a, H (ref) = 148.4 kJ/kg and S (ref) = 0.7967 kJ/kg·K.
What is enthalpy of a refrigerant?
In dealing with liquid and gas pressures in the refrigeration cycle process, never do anything that might result in hydrostatic pressure. Heat content is also known as enthalpy. It is a measure of how much heat a gas or liquid can hold and how much heat is needed to change the temperature.
At what temperature is R134a a liquid?
Properties of R-134a
| No | Properties | R-134a |
|---|---|---|
| 1 | Boiling Point | -14.9°F or -26.1°C |
| 2 | Auto-Ignition Temperature | 1418°F or 770°C |
| 3 | Ozone Depletion Level | 0 |
| 4 | Solubility In Water | 0.11% by weight at 77°F or 25°C |
At what pressure is R134A liquid?
The pressure of R134A at 1.7 °Celsius is 30.4 psig and is highlighted in the chart.
How do you read a pressure enthalpy graph?
On the P-H diagram, pressure is indicated on the y-axis and enthalpy is indicated on the x-axis. Typically enthalpy is in units of Btu/lb and pressure is in units of pounds per square inch (psi). The upside down U figure shown on the diagram designates the points at which the refrigerant changes phase.
What is a pressure enthalpy chart?
The pressure-enthalpy diagram (log P/h diagram) is a very useful tool for refrigerant technicians. First, an explanation of how the diagram is built up is given, and then its use is described. Figure 2.1 shows the principle of a log P/h diagram, and indicates the refrigerant’s various thermodynamic states.
How do you calculate refrigeration enthalpy?
- S1=Sg at -10ºC 0.93782 KJ/Kg.K. Saturated table.
- 244.55 KJ/Kg. Saturated table.
- Isenthropically,S1=S2 at -10ºC 0.93782 KJ/Kg.K. Saturated table.
- Sf 0.4184 KJ/Kg.K. Saturated table.
- Sg 0.9137 KJ/Kg.K. Saturated table.
- Evaporator temperature depend upon. Condenser temperature depends upon the atmosphere.
What is an enthalpy level diagram?
An enthalpy diagram plots information about a chemical reaction such as the starting energy level, how much energy needs to be added to activate the reaction, and the ending energy. An enthalpy diagram is graphed with the enthalpy on the y-axis and the time, or reaction progress, on the x-axis.
What are the thermodynamic properties of R-134a?
Thermodynamic properties of refrigerant R-134a. is a haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane), but with less ozone depletion potential. R-134a has the formula CH2FCF3.
What are the properties of Freon 134a?
Table 1. Freon™ 134a Saturation Properties—Temperature Table (continued) Freon™134a Refrigerant 7 Temp [°C] Pressure Volume [m3/kg] Density [kg/m3] Enthalpy [kJ/kg] Entropy [kJ/(kg)(K)] Temp [°C] kPa (abs) Liquid v f Vapor v g Liquid 1/v f Vapor 1/v g Liquid h f Latent h fg Vapor h g Liquid s f Vapor s g
What are the thermodynamic properties of saturated refrigerant?
Thermodynamic Properties of Saturated Refrigerant R134a Pressure Temperature Specific volume (m^3/kg) Specific volume (m^3/kg) Enthalpy (kJ/kg) kPa °C Sat Liq vf Sat Vap vg Sat Liq hf 60 -36.9 0.0007098 0.3112 3.9 80 -31.1 0.0007185 0.2376 11.3 100 -26.4 0.0007259 0.1926 17.3
What is the heat capacity of HFC-134a?
v = Heat capacity at constant volume in kJ/(kg) (°C) v s = Velocity of sound in m/sec The gas constant, R = 8.314 J/(mole) (K) for HFC-134a, R = 0.0815 kJ/kg·K One atmosphere = 101.325 kPa Reference point for enthalpy and entropy: h f = 200 kJ/kg at 0 °C s