Water leaving a thermoelectric plant condenser at 36 °C enters a cooling tower at a mass flow rate of 3.6x107 kg/h. A flow of cooled water returns to the condenser from the tower at a temperature of 30 °C and with the same flow rate. Make-up water is added separately at 20°C. Atmospheric air is admitted to the cooling tower at 25 °C and with 36% relative humidity. Moist air leaves the tower at 90% relative humidity and 35°C. Determine the mass flow rate of dry air and make-up water, in kg/h. Neglect heat exchanges and fan power. Assume permanent regime.

Water leaving a thermoelectric plant condenser at 36 °C enters a cooling tower at a mass flow rate of 3.6x107 kg/h. A flow of cooled water returns to the condenser from the tower at a temperature of 30 °C and with the same flow rate. Make-up water is added separately at 20°C. Atmospheric air is admitted to the cooling tower at 25 °C and with 36% relative humidity. Moist air leaves the tower at 90% relative humidity and 35°C. Determine the mass flow rate of dry air and make-up water, in kg/h. Neglect heat exchanges and fan power. Assume permanent regime.

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

Chapter36: Refrigeration Applied To Air-conditioning

Section: Chapter Questions

Problem 9RQ: What are higher-efficiency refrigerant blends that can be used as long-term replacements for R-22 in...

See similar textbooks

Similar questions

On a hot summer day, the temperature is 35 ° C, barometric pressure 103 kPa and relative humidity 90%. One The air conditioner draws the outside air and cools it to 20 ° C and raises the air to 12500 L / h. Calculate the condensation rate of the moisture (kg / h) and the flow rate of the air drawn from the outside.
A surface condenser receives steam with a dryness fraction of 0.9 from a turbine. The mass flow rate of the steam into the condenser is 5000kg/hr and the condenser pressure is 16.4kPa. Condensate leaves the condenser with a temperature of 41.6°C. Air leaks into the condenser at a rate of 18.91kg/hr. Determine the volume of air removed per hour (m3/hr) accurate to 4 decimal places assuming that a wet pump is used in the condenser. Gas constant for air can be taken as 0.287 kJ/kg.K. HINT: Only numbers in the answer field, no units to be entered Question 1 of 22
Moist air at 32°C and 60% RH enters the refrigeration coil of a De-humidifier with a flow rate of 1.5 kg/sec. The air leaves saturated at 10°Cand is re-heated to 16°C before entering to the conditioned spaące. Condensate leaves the de-humidifier at 10°C. Determine a. The condensate removed in kg/sec b. The Capacity of the de-humidifier unit (AC - unit) in Tons of refrigeration c. The heat required by the Re-heater Figure: Paychrometric Chart m 1 De-Aamldinier Te panditianed space m m = 1.5 kg/sec Conditioned Supply air w,- W. 10 °C m. air Re - Heater Saun Cue 16°C 32C be
Part C A surface condenser is required to condense 30,000 kg of dry steam per hour at a pressure of 0.04 bar at 29°C. The cooling water enters at 15°C and leaves at 27°C. Assume the overall surface area (As) of the tube is 1200 m² If the velocity of water in the tubes should not exceed 2 m/s, the outside diameter of the tube is 0.025 m and the inside diameter is 0.022 m, determine (i) the heat transfer (ii) mass of cooling water circulated (iii) the number of tubes (iv) the length of each tube and (v) the overall heat transfer coefficient of the tubes. Take the density of water =1000 kg/m3 and specific heat of water =4.187 kJ/kg K.
The air, supplied at the rate of 249.57 gal per second to refrigerated coil, has a saturation humidity of 280 grains water per lb dry air and 13.5% RH. The estimated water flow rate of air entering the refrigerated coil in lb/min is A. 2.32B. 4.71C. 6.25D. 10.31
A single-effect evaporator concentrates 4.00 kg/s of a 10% by mass solution of H2SO4. The entering feed is at 25 °C. The vapor released at the top has a mass flow rate of 3.20 kg/s. The evaporator operates at a total pressure of 30.2 kPa at 90 °C. What is the rate of heat transfer in the evaporator? Use a steam table for the enthalpy of the vapor?
1. Condensation streams through an outlet at a mass movement rate of m=0.2kg/s with a heat loss of 5kW. The enthalpies at creek and exit are 2500kJ/kg and 2350kJ/kg respectively. Assuming negligible velocity at inlet (c1 = 0, the velocity (C2) of team (in m/s) at nozzle exit is
Question 15 Steam at a pressure of 0.08 bar and a quality of 93.2 % enters a shell-and-tube heat exchanger where it condenses on the outside of tubes through which cooling water flows, exiting as saturated liquid at 0.08 bar. The mass flow rate of the condensing steam is 2.4 x 105 kg/h. Cooling water enters the tubes at 15°C and exits at 35°C with negligible change in pressure. Neglecting stray heat transfer and ignoring kinetic and potential energy effects, determine the mass flow rate of the cooling water, in kg/h, for steady-state operation. m water x 106 kg/h
Indonesia Inggris A single effect evaporator was used to concentrate 8000 kg / hr of tomato juice from 5% total solids to 30% total solids. The juice enters the evaporator at 25 ° C. The evaporator is operated on Steam (85% quality) at 143.27 kPa. The vacuum in the evaporator allows the juice to boil at 75 ° C. The specific heat of the dilute material is 4.1 kJ / (kg ° C) and the concentrate product is 3.1 kJ / (kg ° C). Count it (a) The rate of demand for steam? b. Steam economy if condensate temperature is released at 75 ° C.?
Gaisano Mall uses an atmospheric cooling tower to provide cooling for the jacket water of a four-stroke 309 KW diesel generator. The cooling tower efficiency is 53% at a temperature of approach of 11 deg. C. if ambient air has a relative humidity of 60% and dry bulb temperature of 31 deg. C, determine the cooling water supplied to the diesel engine in liters/hour.
A refrigeration system using refrigerant 12 is to have a refrigerating capacity of 80 kW. The cycle is a standard vapor-compression cycle in which the evaporating temperature is -15°C and the condensing temperature 30°C. At the entrance to the evaporator, what is the fraction of vapor in the mixture expressed on a mass basis? 0.97 0.29 0.92 0.27
Moist air enters an air-conditioning system as shown in the figure below at T1 = 28°C, 01 = 80% and a volumetric flow rate of (AV)1 = 0.47 m3/s. At the exit of the dehumidifying section, the air is saturated, @, = 100%, and the condensate leaves this section at the same temperature as the moist air. At the exit of the heating section the moist air is at T3 = 24°C, 03 = 50%. The system operates at steady state, the pressure is 1 bar at all locations, and kinetic and potential energy effects are negligible. Dehumidifying Section Heating Section 2 = 100% T3 = 24°C Ø3 = 50% T1= 28°C $1. (AV)ı Initial dew point- O = 100% Condensate - saturated at T2 T2 T3 ww