Sketch an induced draft counter-flow cooling tower, showing how it may be regulated to control the operation of a refrigeration plant. A cooling tower functions in atmospheric conditions of 23°C db (dry bulb), 17°C wb (wet bulb), cooling 15 kg/s of water from 27°C to 21°C. The air is assumed to leave the top of the tower at 25°C saturated with water. Fan air power input is 5kW. a. b. C. Find the air mass flow induced by the fan for the given cooling duty. Find the evaporative loss (%). Find the make-up water required, taking into account that some moisture is gained by the cooling air.

Sketch an induced draft counter-flow cooling tower, showing how it may be regulated to control the operation of a refrigeration plant. A cooling tower functions in atmospheric conditions of 23°C db (dry bulb), 17°C wb (wet bulb), cooling 15 kg/s of water from 27°C to 21°C. The air is assumed to leave the top of the tower at 25°C saturated with water. Fan air power input is 5kW. a. b. C. Find the air mass flow induced by the fan for the given cooling duty. Find the evaporative loss (%). Find the make-up water required, taking into account that some moisture is gained by the cooling air.

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter45: Domestic Refrigerators And Freezers

Section: Chapter Questions

Problem 12RQ: Refrigerators currently being manufactured in the United States are using______as their refrigerant.

See similar textbooks

Similar questions

3. For an air-conditioning system, the outdoor .. and indoor design dry bulb temperatures are 45°C and 25°C respectively. The space to be air-conditioned is 20m x 30m-x 5 m and infiltration is estimated to be one air are 1.2 (kg of dry air)/m³ and 1.02 kJ/(kg of dry air) °C, then the sensible heat load due to infiltration is, nearly
A meeting hall is maintained at 25°C, 18Cwb. The space has a cooling load of 40 kw of which 32 kw is sensible cooling load. The temperature of the supply air to the space must not be lower than 18°C. Determine A. Sensible heat ratio B. Amount of air supply to the space (kg/s) C. Conditions of supply air D. Capacity of supply fan (CFM)
A compressor is used to increase air pressure with the assumption that there is no heat transfer from/to the compressor. The air is entering at 150 kPa and 37 C and leaving at 650 kPa and 227 C with 250 kg/min as mass rate. The constant-pressure specific heat of air is 1.011 k/kg, and the gas constant is 0.287 k/kg.K while the surrounding is 27"C and 100 kPa. a. Deterrmined the entropy charnges of air after the process. b. Determine the reversible power of the compressor in kW.
Example (1): An air conditioning equipment (figure) have the following: Supply air mass = 1.26 kg/s. The cooling coil receives 20 % outdoor air and 80% return air. Lec. (7) 0 Refrigeration and A/C Outdoor air conditions are: 28°C db, 19.5°C wb Return air conditions are: 22°C db, 50% RH. The mixture air condition outlet the cooling coil are: 10°C db, 0.00735 kg/kgda Draw the system on the Psychrometric chart, then calculate: 1. Cooling coil load. 2. Room sensible heat. 3. Room latent heat. 4. Fresh (outdoor) load. 5. Duct and fan heat gain 6. Sensible heat ratio SHR. If the supply air temperature increases with a value 1°K due to fan motor heat gain and 2°K due to duct heat gain. 0.252 kg/s 1.008 kg/s Dr. Omar M. Ali R الغرفة المراد تكييفها (22,50%) 1.26 kg/s B R
The large insulated flash chamber of a vacuum refrigeration plant is kept at low temperatureby a steam jet which pumps vapor to a condenser . The condensate pump removes thecondensate formed and an air ejector discharges air from the condenser to an air vent .Warm water returns enters the flash chamber at 13 deg C ; chilled water leaves the flashchamber at 4 deg C . The vapor leaving the flash chamber has a dryness factor of 97% andthe condenser inside temperature is 32 deg C . For 100 tons of refrigeration , determine thequantity in cubic meter per minute of chilled water at 4 deg C that the system can provide .A) 0.45 B) 0.56 C) 9.33 D) 0.75
An ammonia compressor has a volumetric efficiency of 85%, operating condensing & evaporating temperatures of 40 C & 10 C respectively for a cooling capacity of 10 tons with compression index of 1.2, mean piston speed of 2 m/s, 5% clearance & bore to stroke ratio of 0.7. Determine the following 1. Draw the PH Diagram indicating the temperatures, enthalpies & initial specific volume 2. Refrigerating Effect in kJ/kg 3. Mass flow rate in kg/s
9. When developing a certain power, the specific fuel con- sumption of an internal combustion engine is 0-255 kg/kWh (brake) and the mechanical efficiency is 86% Calculate (i) the indicated thermal efficiency, and (ii) the brake thermal efficiency, taking the calorific value of the fuel as 43-5 MJ/kg. If 35 kg of air are supplied per kg of fuel, the air inlet being at 26°C and exhaust at 393°C, find (iii) the heat energy carried away in the exhaust gases as a percentage of the heat supplied, taking the specific heat of the gases as 1-005 kJ/kg K.
1. Moist air enters a refrigeration coil at 89 F dry-bulb temperature and 65 F thermodynamic wet bulb temperature at a rate of 14oo cu ft per min. The surface temperature of the coil is 55 F . If 3.5 tons of refrigeration are available, find the dry bulb and wet bulb temperatures of the air leaving the coil. Assume sea level pressure.
3. An ice plant produces 10 tonnes of ice per day at 0°C, using water at room temperature of 20°C. Estimate the power rating of the compressor motor if the C.O.P. of the plant is 2.5 and overall electromechanical efficiency is 0.9. Take latent heat of freezing for water = 335 kJ/kg Specific heat of water = 4.18 kJ/kg. [Ans. 21.44 kWI
1. A variable-air-volume cooling system delivers air to a controlled space maintained at 24 C db and 17 C wb. Under design conditions, the total cooling load is 60 kW with a sensible heat factor of 0.60, and the supply air temperature is 16 C db. At minimum load, about 7.5 kW with SHF of 0.80, the air quantity may be reduced no more than 75% by volume of the full load design value. Calculate the minimum volume of air to be supplied to the space at minimum load, cu.m/min.
A steam condenser receives 10 kg per second of steam with an enthalpyof 2570 KJ/kg. Steam condenses into liquid and leaves with an enthalpy of160 KJ/kg, if cooling water passes through the condenser with temperatureincreases from 13 o C to 24 o C. Calculate the cooling water flow rate inkg/sec.
Find the efficiency of the cooling tower with following working conditions: The air inlet dry bulb and wet bulb temperatures are 24.50Cand 16.80C respectively. The air outlet dry and wet bulb temperatures are 25.60Cand 170C respectively. The water inlet and outlet temperatures are 20.80Cand 190C respectively.