An air-conditioner provides 0.5 lbm/s of air at 69F cooled from outside atmospheric air at 90F.Estimate...
An air-conditioner provides 0.5 lbm/s of air at 69F cooled from outside atmospheric air at 90F.Estimate the amount of power needed to operate the unit assuming it has a coefficient ofperformance that is half of what a Carnot unit would have.
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An air-conditioner provides 0.5 lbm/s of air at 69F cooled from
outside atmospheric air at 90F.Estimate...
3. A cold storage facility is maintained at 20°F when the outside air temperature is 90°RF...
3. A cold storage facility is maintained at 20°F when the outside air temperature is 90°RF by an air conditioning unit operating as a cycle at steady state. The unit must remove 120,000 Btu/h continuously from the facility to maintain the required indoor temperature, and has a power input of 20 hp Determine: the actual coefficient of the air conditioning unit the minimum theoretical horsepower that would be required to operate a cooling unit under these conditions. (1hp 2545 Btu/h)...
Q.3 Outside air at 90°F, 1 atm, and 95% relative humidity with a flow rate of...
Q.3 Outside air at 90°F, 1 atm, and 95% relative humidity with a flow rate of 4000 cfm is blown over an evaporator of a refrigeration system and exits at 75°F and 60% relative humidity. The refrigeration system has operating with the COP of 2.5. Determine (a) the amount of cooling provided by the evaporator Btu/hr (b) the amount of water condensed in the evaporator, lbm/hr and (c) the power required by the compressor of the refrigerator in kW. 1...
the examinatiU to Heat Transfer" by Frank P. Incropera and Bavid F. Air entering a circular...
the examinatiU to Heat Transfer" by Frank P. Incropera and Bavid F. Air entering a circular stainless steel tube D 50 mm outside diameter by d 45 mm inside diameter by L 5 m long atTa 20 C is heated by saturated steam at T100 c through which the tube passes. The thermal conductivity of the stainless steel tube kss .. 16.3 w/m° ? and the heat transfer coefficient at the interface between the tube and the steam h. 5000...
System Model: Automotive Air Conditioning System Outside Air Temp: 45 oC Car Interior Air Temp: 22...
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...
Problem2 (a) Suppose outside temperature is 55 °F while the temperature inside a building is 72 F. The building is heated but not air conditioned, so the partial pressure of water vapor is the sa...
Problem2 (a) Suppose outside temperature is 55 °F while the temperature inside a building is 72 F. The building is heated but not air conditioned, so the partial pressure of water vapor is the same both inside and outside the building. Finally, suppose the dew point outside is 40°F What is the dew point inside? What are the relative humidities inside and outside the building? (We are most comfortable if relative humidity is between 30% and 50%-This question shows why...
3. (3 pts) Convert a mass flow rate of 195 kg/s of air (typical of the...
3. (3 pts) Convert a mass flow rate of 195 kg/s of air (typical of the airflow through a turbofan engine) to cfm (cubic feet per minute) at standard atmospheric pressure. (You will have to look up the specific volume of air at standard atmospheric pressure in m3/kg via Google) 4. (6 pts) Compute the power output of a 225-hp engine in a) British thermal units per minute (Btu/m) and b) kilowatts 5. (2 pts) How much does 1 kg...
4. Air-Conditioning Unit [20 Marks] 1 m3/s of moist air at 32 °C with a relative...
4. Air-Conditioning Unit [20 Marks] 1 m3/s of moist air at 32 °C with a relative humidity of 70% is to be treated by a simple air condition system to produce air at 18 °C with a relative humidity of 50% The system will have two stages. In the first stage, the air will pass over cooling coils to dehumidify it, and in the second stage it will be heated electrically to the specified outlet conditions You may ignore the...
. A typical commercial wind turbine costs approximately $2 million per MW of installed power and...
. A typical commercial wind turbine costs approximately $2 million per MW of installed power and requires 5.76 TJ per million dollars of energy to manufacture the wind turbine. (a) Calculate the amount of energy that is consumed (i.e. energy invested) in the manufacture ofa 1.5 MW wind turbine, assuming that turbine manufacture requires 5.76 TJ per million dollars spent. (TJ Tera-joules 1012 joules) (b) If the wind turbine has blades that are 40 meters (radius) long and the average...
1. A rocket is launched vertically from the Earth, and the thrust (pushing force) from the engines...
1. A rocket is launched vertically from the Earth, and the thrust (pushing force) from the engines is directed upward, and has a magnitude of 5.00 x 106 N. The mass of the rocket is initially 2.00 x 105 kg. (a) What is the initial acceleration of the rocket, assuming you can neglect air resistance? (b) After the rocket has been in flight for a while, burning and exhausting a lot of fuel, its mass has decreased to 1.20 x 105 kg, and...
Review Constants Periodic Table Air consists mostly of nitrogen (N), with a molecular mass of 28, and oxygen (O2),...
Review Constants Periodic Table Air consists mostly of nitrogen (N), with a molecular mass of 28, and oxygen (O2), with a molecular mass of 32. A water molecule (H,O) has molecular mass 18. According to the ideal gas law (N/ V P /KT), dry air at a particular pressure and temperature has the same particle density (number of particles per unit volume) as humidait at the same pressure and temperature. Consequently, humidair, whose low-mass water molecules replace more massive nitrogen...
3. A cold storage facility is maintained at 20°F when the outside air temperature is 90°RF by an air conditioning unit operating as a cycle at steady state. The unit must remove 120,000 Btu/h continuously from the facility to maintain the required indoor temperature, and has a power input of 20 hp Determine: the actual coefficient of the air conditioning unit the minimum theoretical horsepower that would be required to operate a cooling unit under these conditions. (1hp 2545 Btu/h)...
Q.3 Outside air at 90°F, 1 atm, and 95% relative humidity with a flow rate of 4000 cfm is blown over an evaporator of a refrigeration system and exits at 75°F and 60% relative humidity. The refrigeration system has operating with the COP of 2.5. Determine (a) the amount of cooling provided by the evaporator Btu/hr (b) the amount of water condensed in the evaporator, lbm/hr and (c) the power required by the compressor of the refrigerator in kW. 1...
the examinatiU to Heat Transfer" by Frank P. Incropera and Bavid F. Air entering a circular stainless steel tube D 50 mm outside diameter by d 45 mm inside diameter by L 5 m long atTa 20 C is heated by saturated steam at T100 c through which the tube passes. The thermal conductivity of the stainless steel tube kss .. 16.3 w/m° ? and the heat transfer coefficient at the interface between the tube and the steam h. 5000...
Problem2 (a) Suppose outside temperature is 55 °F while the temperature inside a building is 72 F. The building is heated but not air conditioned, so the partial pressure of water vapor is the same both inside and outside the building. Finally, suppose the dew point outside is 40°F What is the dew point inside? What are the relative humidities inside and outside the building? (We are most comfortable if relative humidity is between 30% and 50%-This question shows why...
3. (3 pts) Convert a mass flow rate of 195 kg/s of air (typical of the airflow through a turbofan engine) to cfm (cubic feet per minute) at standard atmospheric pressure. (You will have to look up the specific volume of air at standard atmospheric pressure in m3/kg via Google) 4. (6 pts) Compute the power output of a 225-hp engine in a) British thermal units per minute (Btu/m) and b) kilowatts 5. (2 pts) How much does 1 kg...
4. Air-Conditioning Unit [20 Marks] 1 m3/s of moist air at 32 °C with a relative humidity of 70% is to be treated by a simple air condition system to produce air at 18 °C with a relative humidity of 50% The system will have two stages. In the first stage, the air will pass over cooling coils to dehumidify it, and in the second stage it will be heated electrically to the specified outlet conditions You may ignore the...
. A typical commercial wind turbine costs approximately $2 million per MW of installed power and requires 5.76 TJ per million dollars of energy to manufacture the wind turbine. (a) Calculate the amount of energy that is consumed (i.e. energy invested) in the manufacture ofa 1.5 MW wind turbine, assuming that turbine manufacture requires 5.76 TJ per million dollars spent. (TJ Tera-joules 1012 joules) (b) If the wind turbine has blades that are 40 meters (radius) long and the average...
Review Constants Periodic Table Air consists mostly of nitrogen (N), with a molecular mass of 28, and oxygen (O2), with a molecular mass of 32. A water molecule (H,O) has molecular mass 18. According to the ideal gas law (N/ V P /KT), dry air at a particular pressure and temperature has the same particle density (number of particles per unit volume) as humidait at the same pressure and temperature. Consequently, humidair, whose low-mass water molecules replace more massive nitrogen...
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