Problem 4.069 The figure belows shows three components of an air-conditioning system, where T3 115°F and...
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In a produce chilling system, air is cooled by being passed over a heat exchanger coil througlh which R-134a flows steadily at a rate of 15 lbm/min. Prior to entering the heat exchanger coil, the refrigerant passes through a throttling valve as shown in the figure below. The R-134a enters the valve as a saturated liquid at high pressure (which will be varied) and leaves at 35 psia. The refrigerant leaves the heat exchanger coil as...
Problem: The condenser in an air conditioning system is a heat exchanger in which cool air absorbs latent energy from the refrigerant, condensing the refrigerant from vapor to liquid. Refrigerant R-134 enters the condenser at 1 MPa and 90°C. It leaves the condenser at 1 MPa and 30°C. Cool air enters the condenser at 100 kPa and 27°C at a volume flow rate of 10 m3/s, and it leaves at 95 kPa and 60°C. Assume the specific heat of the...
-Rome can get pretty hot in the mid-summer! Most of the air conditioning units in the Tiber campus use the working fluid R-134a (1,1,1,2-tetrafluoroethane), which is replaces the less environmentally-friendly R-12 of years ago. a) Illustrate the following air conditioning cycle, indicating material, heat, and work flows, as well as given/known temperatures and pressures: R-134a is pressurized to 10.2 bar in an adiabatic, reversible compressor. This high-pressure, hot refrigerant is condensed outside of the building using ambient air to a...
System Model: Automotive Air Conditioning System Outside Air Temp: 45 oC Car Interior Air Temp: 22 oC Heat Load = 4.2 kJ/sec rate at which heat must go in to the air conditioner to be removed from the car’s interior Refrigerant: R134a HINT: Heat enters an air conditioning system where? Refrigerant 134a … - leaves the evaporator coil and enters the compressor as a saturated vapor at the evaporator pressure of 2.8 bars. - It leaves the compressor at...
4. Refrigeration and air conditioning is quite useful, but it is, in effect, a way to move heat from a low temperature to a high temperature. Is this possible, given the second law? Answer the following questions below, for R-134a (a common refrigerant), and then state whether you believe refrigeration violates the second law, and why (or why not) a. R-134a arrives to the inside of the refrigerator that you are trying to keep cooled to T- 4°C. The air...
(3) Figure 3 shows a system including three components: heater, thermostat, and room. Assume the initial room temperature is 0 C. The heater is turned on to heat the room to the desired temperature 25'C (i.e heater temperature is 25 C). A fan takes room air, and passes it through the heater and back to the room, with volumetric air flow rate q,. The density of air is assumed to 1.225 kg/m The space of the room is 30 m....
7. Air [R=1715 ft·lb/(slug R), cp = 6003 ft-lb/(slug-R)] flows steadily, as shown in the figure, through a turbine which produces 700 hp. For the inlet and exit conditions shown, estimate (a) the exit velocity V2 and (b) the heat transferred in Btu per hour. Hint: The specific enthalpy of an ideal gas is h = CAT. w,700 hp Turbomachine D = 6 in P = 150 lb/in? Ti - 300°F V = 100 ft/s D -6 in P2 -...