Determine the thermal effieincy of a heat transfer process

[daftpunk]

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

 

[rock.freak667]

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.

 

[daftpunk]

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

 

[rock.freak667]

That should be correct.

 

[daftpunk]

thanks