Problem 5 Space, at sea level, is to be maintained at 75°f db and -50%. 100% fresh air at 110°F db and o-20% is supplied to the heat recovery unit which uses the return air to cool the fresh air before draw off this air as shown in the figure. The heat recovery unit will reduce the fresh air by 20°F. The surface temperature of the cooling coil is 50 °F and delivers air to the space at 60°F db. d. Draw the process on the psychrometric chart. e. What is the off coil (point 3) relative humidity. What is the wet bulb temperature of the fresh air leaving the heat recovery unit (point 2)? f. How much heat was removed by the cooling coil per unit mass of dry air. g. How much energy was saved by using the heat recovery unit per unit mass of dry air?

An ammonia system with a 158-kW evaporator operating at -1°C and a 35-kW evaporator operatingat -40°C uses flash gas removal and intercooling. The condensing temperature is 32°C. Thearrangement is as shown. How many kilograms per minute of ammonia are compressed by the high-pressure compressor?

Steam CERE KJ -Valve Control volume boundary Turbine Initially evacuated tank In case of emergencies, a turbine is connected to an active steam pipe line using a valve. When the valve is opened, steam from the pipe line, which is initially at 550°C and 10 MPa, flows through the turbine into a 0.64 m³ tank, which is initially evacuated. The valve is closed when the pressure inside the tank is 1.6 MPa and the temperature in the tank is 300°C. If the entire process is completed adiabatically, what is the amount of work generated from the turbine?

ercise 6 6.1 A surface condenser is fitted with separate air and condensate outlets. A portion of the cooling surface is screened from the incoming steam and the air is passes over these screened tubes to the air extraction and becomes cooled below the condensate temperature. The condenser receives 20 000kg/hr of dry saturated steam at 36.2°C. At the condensate outlet the temperature is 34.6°C TK and at the air extraction the temperature is 29°C. The volume of air and vapour leaving the condenser is 3.8m3/min. Assume constant pressure throughout the condenser, calculate: 6.1.1 the mass of air removed per 10 000kg of steam (2.63kg); 6.1.2 the mass of steam condensed in the air cooler per minute (0.5kg/min)%3B 6.1.3 the heat rejected to the cooling water (13451kW).