13. Toreduce the volumetric flow rate and, therefore, the power required for compression insubsequent stages, multistage compressors often have intercoolers that reduce the temperature of the gas being compressed as it travels between successive stages. The main function of the intercooler is_____ .
(A) to increase the enthalpy of working fluids
(B) to increase the entropy of working fluids
(C) to reduce the specific volume of working fluids
(D) to increase the internal energy of working fluids