4245

4016

كارشناسي ارشد

تبديل انرژي

اصفهان : دانشگاه صنعتي اصفهان، دانشكده مكانيك

1387

[سيزده]، 131، [II] ص. : مصور، جدول، نمودار

ص. ع. به: فارسي و انگليسي

احمد رضا عظيميان

احمد صداقت

23/7/1387

احمد صابونچي، علي اكبر عالم رجبي

مهندسي مكانيك

ID4016

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

AbstractIn the last decades increasing energy cost have caused a special attention to optimizationof energy usage So many studies and researches have been carried out to improve andcorrect different industrial processes that use various types of energy Power plants areone of the major units in the industry of any country Therefore it is an essential task tosimulate these units and their different components in order to increase their performanceand efficiency Dry cooling towers are one of the most important components of a powerplant Performance of dry cooling towers is strongly affected by wind flow and ambienttemperature Generally speaking Wind flow and increasing ambient temperaturedecreases performance of dry cooling tower that results in power plant output power andefficiency reduction These negative effects can sometimes lowers total power plantpower production capacity up to 40 percent This energy loss imposes a big damage onpower plant and this is the reason of why dry cooling towers must be studied In this work a commercial numerical code was used to simulate the fluid flow and heattransfer First geometry of a dry cooling tower was constructed and a suitable grid wasproduced for it Next to ensure validity of geometry grid its boundary conditions andsolution parameters simulation of dry cooling tower in wind flow for ambienttemperature of 15 oC that has been carried out before by some researchers was done andthe results was compared with theirs The agreement was acceptable In the next step theeffect of ambient temperature on performance of dry cooling tower was studied Theresults containing heat exchangers heat transfer and outlet water temperature distribution show that increasing ambient temperature lowers heat transfer from heat exchangers andincrease the water outlet temperature from them and finally reduces the performance ofdry cooling tower This amount of decrease in heat exchangers heat transfer and increasein their outlet water temperature is not equal for all heat exchangers of cooling tower anddepends on location of heat exchangers around the tower In this work the effect ofunequal water mass flow division between tower sectors and heat exchangers as asolution to improve the performance of cooling tower in wind was studied too Theresults of this study show that if water mass flow can be distribute properly betweentower sectors it can improve performance of tower in wind Also if water mass flow hasbeen divided between tower sectors in a certain manner only one water mass flowdistribution between heat exchangers can optimize the performance of dry cooling towerin wind

احمد رضا عظيميان

احمد صداقت

احمد صابونچي، علي اكبر عالم رجبي