7.21- In a textile manufacturing plant, the waste dyeing water (Cp = 4295 J/g Cº) at 75C° is to be used to preheat fresh water (Cp = 4180 J/kg ·Cº) at 15C° at the same flow rate in a double-pipe counter-flow heat exchanger. The heat transfer surface area of the heat exchanger is 1.65m² and the overall heat transfer coefficient is 625 W/m² Cº. If the rate of heat transfer in the heat exchanger is 35kW, determine the outlet temperature and the mass flow rate of each fluid stream. Answers: 41.4C, 49.3C°, 0.317 kg/s Fresh water 15°C Dyeing water 75°C Th, out

7.21- In a textile manufacturing plant, the waste dyeing water (Cp = 4295 J/g Cº) at 75C° is to be used to preheat fresh water (Cp = 4180 J/kg ·Cº) at 15C° at the same flow rate in a double-pipe counter-flow heat exchanger. The heat transfer surface area of the heat exchanger is 1.65m² and the overall heat transfer coefficient is 625 W/m² Cº. If the rate of heat transfer in the heat exchanger is 35kW, determine the outlet temperature and the mass flow rate of each fluid stream. Answers: 41.4C, 49.3C°, 0.317 kg/s Fresh water 15°C Dyeing water 75°C Th, out

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.49P

See similar textbooks

Similar questions

In a single-body, four-pipe transition heat exchanger, the hot combustion product gases are cooled by water. Flow of gases 3 kg / s, specific temperature0.95 kJ / kg.°C; water flow 0.2 kg / s, specific temperature 4.2 kJ / kg.°C dir. The total heat transfer coefficient of the heat exchanger is 300 W / m2.K, heat transfer surface area is 10 m2.a) the heat transfer that occurs and the output temperatures of both fluids;b) find the logarithmic mean temperature difference.
Water enters the single shell,two-pass heat exchanger at 16°C and leaves at 40°C. It is heated by gases that enter at 120°C and leave at 38°C. Determine the true mean temperture difference. A. 44.93K B. 36K C. 27K D. 50K
Concentric Tube Heat Exchanger For equivalent inlet conditions, why should a counterflow heat exchanger have better effectiveness than a parallel unit?
(a) An Ocean Thermal Energy Converter (OTEC) pumps 200 m^3/s through a heat exchanger in which the temperature (expressed in Kelvins) drops by 1%. All the heat extracted is delivered to the ammonia boiler [11. The ammonia temperature. THT at turbine inlet is equal to the mean temperature of the water in the warm water heat exchanger minus 1 °K. The temperature, TCT, of the ammonia leaving the turbine is kept at 10 °C by the cooling effect of 250 m³/s of cold water. The efficiency of turbine/generator system is 90% of the Carnot efficiency of a heat engine working between THT and TCT . 12 MW of the produced electricity is used for pumping. Heat capacity of water is 4.2 MJ m³ K-1. Calculate the intake temperature of the warm water for the following cases: i) A total of 20 MW of electricity is available for sale? ii) The OTEC produces exactly equal to the amount of power needed for pumping?
THERMOFLUID A thin-walled double-pipe counter-flow heat exchanger is used to cool oil (C, = 2.20 kJ/kg.°C) from 150 to 40°C at a rate of 2 kg/s by water (c, = 4.18 kJ/kg.°C) that enters at 22°C at a rate of 1.5 kg/s. Determine the rate of heat transfer in the heat exchanger and the exit temperature of water.
A counterflow double-pipe heat exchanger is used to heat water from 20 deg * C to 40 deg * C with ahot oil which enters the exchanger at 180 deg * C and leaves at 140 deg * C The flow rate of wateris 3.0 kg/s and the overall heat-transfer coefficient is 200 W/m2.K. Assume the specificheat for oil is 2100 J/ kg .K. Suppose the water flow rate is cut in half. 1. What new oil flow rate would be necessary to maintain a 40 deg * C outlet watertemperature?
A surface condenser is to operate under the following conditions: 45,000 kW turbine, exhaust steam rate is 8 lb/kW-hr, 2” Hg absolute condenser pressure, ¾” no. 17 BWG admiralty tubes, 500F inlet water temp., 8 ft/s water velocity, 85% cleanliness factor, 15 0F terminal difference, 80% pump efficiency and 5ft friction drop in tunnels and pipes. Calculate the following: Surface Area (ft2) Volume of cooling water (gpm) Number of tubes Actual length of tubes Pump-motor power (hp)
What is the advantage of using heat exchanger in plant designing compared to other heat transfer equipments?
THERMODYNAMICS - Heat Exchanger UPLOAD COMPLETE SOLUTION. Consider a water-cooled condenser in a large refrigeration system in which R-134a is the refrigerant fluid. The refrigerant enters the condenser at 1.0 MPa and 60◦C, at the rate of 0.2 kg/s, and exits as a saturated liquid at 0.95 MPa. Cooling water enters the condenser at 10◦C and exits at 20◦C. Compute for the rate of heat transfer and the rate at which cooling water flows through the condenser.
Mechanical engineering : Heat transfer 1. Determine the overall heat transfer coefficient and flow rate required while using a heat exchanger , the water is enetered at 20◦C through the tubes of small single pass and the water comes out with a temperature at 40◦C. 25 kg/min of steam condenses at 60◦C on the shel side ,the area of the exchanger is 12 m2. (The latentheat, hfg, is 2358.7 kJ/kg at 60◦C.) 2 . You have unpainted aluminum siding on your house and the engineerhas based a heat loss calculation on U = 5 W/m2K. You discover thatair pollution levels are such that Rf is 0.0005 m2K/W on the siding.Should the engineer redesign the siding? If not sure skip, wrong may downvote
consider parallel flow heat exchanger
Using that information and this table For the average monthly rate of geothermal heat available, determine, for the real case: in a tabular format and show sample calculation for one month. the necessary monthly average mass flow rate (in kg/s) of the refrigerant that must be pumped through the heat exchanger to collect the thermal energy from the available geothermal hot water flow rate if the hot water was cooled by 5°C. What should be the flow capacity (in kg/s) of feed pump of the ORC heat engine that you are designing and the monthly average net electric power generation capacity (in kW). 2. the monthly average net electric power generation capacity (in kW) and yearly average net electrical power generation capacity (in kW).