An air-conditioner which uses R-134a operates on the ideal vapor compression refrigeration cycle with a given compressor efficiency. --Given Values-- Evaporator Temperature: T1 (C) = 9 Condenser Temperature: T3 (C) = 39 Mass flow rate of refrigerant: mdot (kg/s) = 0.027 Compressor Efficiency: nc (%) = 90 a) Determine the specific enthalpy (kJ/kg) at the compressor inlet. Your Answer = b) Determine the specific entropy (kJ/kg-K) at the compressor inlet Your Answer = c) Determine the specific enthalpy (kJ/kg) at the compressor exit Your Answer = d) Determine the specific enthalpy (kJ/kg) at the condenser exit. Your Answer = e) Determine the specific enthalpy (kJ/kg) at the evaporator inlet. Your Answer = f) Determine the coefficient of performance for the system. Your Answer = g) Determine the cooling capacity (kW) of the system. Your Answer = h) Determine the power input (kW)to the compressor. Your Answer =

To determine the various thermodynamic properties and performance parameters of the refrigeration system, we need to understand each process in the vapor-compression cycle and use data from the refrigerant (R-134a) property tables or a refrigeration software.

a) Specific enthalpy at the compressor inlet (h1): This is the specific enthalpy at the evaporator exit, where the refrigerant is in the saturated vapor state at the evaporator temperature (T1). We look up the saturation temperature corresponding to T1 for R-134a in the refrigerant property tables and find the specific enthalpy of the saturated vapor, which we will call h1.

b) Specific entropy at the compressor inlet (s1): This is the entropy of the refrigerant in the saturated vapor state at the evaporator temperature (T1). Similar to the specific enthalpy, we find the specific entropy (s1) at the given temperature by looking up the saturated vapor entropy of R-134a in the refrigerant tables at T1.

c) Specific enthalpy at the compressor exit (h2): The enthalpy at the compressor exit can be found by considering the isentropic efficiency of the compressor. The isentropic enthalpy (h2s) at the compressor exit is found by looking up the tables for the entropy s1 (same as the compressor inlet) at the condenser temperature T3 assuming an isentropic process. Given the compressor efficiency, we calculate the actual enthalpy h2 using the following relationship:

h2 = h1 + (h2s - h1) / ηc,

Where ηc is the compressor efficiency (0.90 or 90%).

d) Specific enthalpy at the condenser exit (h3): This is the specific enthalpy of the saturated liquid at the condenser temperature (T3). We find the specific enthalpy of the saturated liquid, which we will call h3, from the refrigerant R-134a saturation tables at T3.

e) Specific enthalpy at the evaporator inlet (h4): Assuming an ideal cycle, the isenthalpic expansion process occurs in the expansion valve, so h4 equals h3.

f) Coefficient of performance (COP) for the system: COP is defined as the ratio of the cooling effect to work input.

COP = QL / W,

Where QL = mdot * (h1 - h4) and W = mdot * (h2 - h1).

g) Cooling capacity of the system: The cooling capacity is the rate at which heat is removed from the evaporator, and it's calculated with the formula:

Cooling capacity (Q̇L) = mdot * (h1 - h4).

h) Power input to the compressor: The power input to the compressor needed to drive the vapor compression cycle is calculated by:

Power input (Ẇ) = mdot * (h2 - h1).

Without the actual R-134a refrigerant tables, further calculations cannot be completed. These would be the logical steps a student should follow, utilizing the given refrigerant properties' data to determine the system's performance.