Determine the thermal effieincy of a heat transfer process

AI Thread Summary
To determine the thermal efficiency of the heat transfer process, the input power is 3 kW, and 1.7 liters of water is heated from 313 K to 375 K in 2.5 minutes. The specific heat capacity of water is 4.19 kJ/kgK, which is used to calculate the heat required for the process. The output power is calculated as approximately 2.91 kW, leading to a thermal efficiency of about 98.1% when compared to the input power. The calculations confirm the accuracy of the thermal efficiency result.
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Homework Statement


determine the thermal effieincy of a heat transfer process where the following data has been used
Input=3kW
1.7 litres of water have been heated from 313K to 375K in 2.5 minutes
specific heat capacity of water= 4.19kj/kgK

Homework Equations


Thermal efficiency= network done (W)
total heat supplied (Q)




The Attempt at a Solution


am struggling where to start only done simple tasks
 
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Well you have 1.7 L of water being heated from 313 K to 375 K. So how much heat does this require? (look at the units of specific heat capacity). This will be your work done W.

In order to convert this to Watts, you will need to use the formula Power = work done/time.
 
output=1.7*4.19*(375-313)/(2.5*60)=2.914473Kw. 2.9174473/3= 0.981 or 98.1%. Thanks a lot for help could you confirm this
 
That should be correct.
 
thanks
 

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