Air leaving a drier is frequently recirculated to minimize energy consumption. Calculate the fraction of the...
fluid 12 6 Problem 5.12 An evaporative cooling tower (see the figure below) is used to cool water from 110 to 80 °F . Water enters the tower at a rate of 250,000 lbm/hr. Dry air (no water vapor) flows into the tower at a rate of 151,000 lbm/hr. If the rate of wet airflow out of the tower is 156,900 Ibm/hr. determine the rate of water evaporation in lbm/hr and the rate of cooled water flow in lbm/hr. Wet...
4. Liquid water at 100°F and 200 gal/min volumetric flow rate enters a cooling tower operating at steady state. Atmospheric air enters with a dry-bulb temperature of 80°F and a wet-bulb temperature of 60°F. Moist air exits the cooling tower at 90° and 90% relative humidity. Makeup water is provided at 80°F. Calculate the mass flow rates of the dry air and makeup water, each in lb/min, versus return water temperature at 80, 90, and 100°F. Ignore kinetic and potential...
2. (25 pts) Nuclear power plants have large amounts of heated water to cool, which may be done in a cooling tower. A sample tower reduces the temperature of warm water from 130 F to 90'F (see figure at right). Air without water vapor flows into the tower at Wet air 156,900 b/hr 151,000 lb/hr Given that the air removing heat along with some water flows at 156,900 lb/hr, what is the flowrate of the cooled warm water 250,000 lb/hr...
56. Fresh air is introduced into a room at such a rate that the air in the room is changed every 5 minutes. The room is 30 by 30 by 10 ft and the air in the room is at 70 °F with a percentage humidity of 60. Outside air at a temperature of 60 °F is used as air supply. The outside air is heated to the room temperature by a heat exchanger. How many BtU per hour must...
(10 pts) Six-thousand cubic feet per minutes (C.F.M.) of atmospheric air at 28°C (dry bulb) having a wet bulb temperature of 23°C is to be cooled in an air conditioning system. The air conditioning system lowers the dry bulb temperature of the air to 20° C. Cooling with dehumidification is accomplished using chilled water loop. The chilled water enters the loop at 5°C at a rate of 280 kg/min and experience a 5°C temperature increase. The atmospheric pressure is 1...
a. Calculate the dry air and water vapor mass flow rates (lb/min) if the volume flow rate is 1,000 cfm, the humidity ratio is 0.025 lbv/lba, and the dry air density is 0.072 Iba/ft3. b. Assume the above air enters an evaporator coil at 90°F where it is cooled in a constant humidity ratio process until reaching the 100 % RH curve ( the temperature at that point is the dew point. The air then keeps dropping in temperature, following...
H1- COOLING TOWER [10 p] 1. What is the wet bulb temperature? How can you measure it? Is the wet-bulb temperature greater than dry-bulb temperature? Why? [10 p] 2. A cooling tower is to be designed to cool 8 kg/s of water from 37°C to 29 °C. Entering air is 25 °C and at 30 % relative humidity. Leaving air is 22 °C and at 90% relative humidity. a) Calculate the air flow rate, G. b) Determine the possible lowest...
An Conference Center is to be air-conditioned for a seating capacity of 3200 people for the following outdoor and comfort conditions a) Outdoor design conditions = 35 °C, db and 65% R.H b) Indoor/return design conditions-26 deg C. db and 55% RH. c) Total sensible room load = 420,000 kJ/hr d) Total latent room load = 200,000 KJ/hr e) The rise in dry bulb temperature of the air inside the conference center is limited to 9 °C (i.e. the Supply...
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...
can you help me how to get the h, h* and (h*-h)L (highlighted in yellow colour)? EXAMPLE 19.3. A counterflow induced-draft cooling tower operates with inlet and exit water temperatures of 105 and 85°F when the air has dry-bulb and wet-bulb temperatures, respectively, of 90 and 76°F. The tower has 4 ft of stacked plastic fill, and the flow rates are G, = 2,000 lb/h. ft? and G: = 2,200 lb/h. ft?. (a) Determine the number of transfer units, the...