بررسي عملكرد پمپ حرارتي شيميايي با سيستم جذب سطحي

چكيده انگليسي :

Investigation on the Performance of Chemical Heat Pump with Adsorption Process Milad Zahir m zahir@me iut ac ir Date of Submission May 17 2011 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Alemrajabi Assoc Prof AbstractAs a result of heavily urbanized societies and their consequent need through the last decades CFCs have beenwidely used in compressor equipped air conditioning systems Although these kinds of equipments are used alot various questions have been raised against the use of them This is due to compressor s high energyconsumption low efficiencies in power plants and environmental crises Therefore world wide scientific andresearch motivation has been sharply increasing to limit the use of CFCs and make energy consumption moreefficient The goal of this project is based on design and construction of an experimental prototype of an adsorptionchiller and analysis of different parameter s effect on its performance In comparison to previous works thischiller is very small in dimension and a small quantity of silica gel mass is used in it which make the device aunique one Furthermore to increase the heat transfer through the heat exchanger chamber epoxy resin is usedto attach silica gel pieces to the heat exchanger surface Thus the chiller could be categorized as an adsorptionchiller with coated heat exchanger The unit contains an adsorption chamber evaporator and a condenser Also a mercury vacuum manometer hasbeen designed and installed on the unit to measure the pressure in different parts After production and making sure that the unit is perfectly sealed some tests were done to investigate the effectof different parameters on its performance These parameters are temperature of hot water source inlet to theadsorption chamber the temperature of cold water source inlet to the condenser the temperature of chilledwater inlet to the evaporator hot and cold water flow through the heat exchanger chamber system primaryvacuum pressure and cycle duration Duo to existing constraints the device performance is lower than what was expected Analysis shows that themost important causes for low performance are tiny dimension of the device minute amount of silica gel massusage and pressure losses in the system Tests results show that any increase in the hot water source temperatureor in the cool water source temperature will cause a rise in the coefficient of performance COP and specificcooling power SCP On the other hand an increase in the temperature of cold water source will reduce theCOP and SCP Also it was proved that an increase in the mass flow rates of hot and cold water passing throughthe heat exchanger of adsorption chamber slightly raises the COP and SCP However if the system primaryvacuum pressure is increased these two parameters would be dramatically reduced Based on the test results there will be an optimum cycle duration for which the SCP is maximum Thisphenomenon occurs in the cycle duration of 12 minutes 6 minutes of desorption half cycle plus 6 minutes ofadsorption half cycle Key Words adsorption silica gel chiller chemical heat pump

ظهير، ميلاد

بررسي عملكرد پمپ حرارتي شيميايي با سيستم جذب سطحي

سيليكاژل , چيلر