I need some clarification Thermo Cycle

[Saladsamurai]

I need some clarification! Thermo Cycle

Homework Statement

One kg of Refrigerant 22, initially at p1=.9MPa, u1=232.92 kJ/kG, is contained within a rigid closed tank. The tank is fitted with a paddle wheel that transfers energy to the refrigerant at a constant rate 0.1kW. Heat transfer from the refrigerant to its surroundings occurs at a rate Kt, in kW, where K is a constant, in kW/minute, and t is time in minutes. After 20 minutes of stirring, the refrigerant is at p2=1.2 MPa, u2=276.67 kJ/kG. No overall changes in KE or PE occur. (a) For the refrigerant, determine the Work and Heat transfer, each in kJ. (b) Determine the value of the constant K appearing in the given heat-transfer relation in kW/min.

Homework Equations

U2-U1=Q-W
W=int p*dV

The Attempt at a Solution

I guess what I really need is some clarification on the term "energy transferred in." Is this a rate of WORK?

 

[Saladsamurai]

Can anyone give me a hint before I go to bed? Then I can mull it over and attack this problem on the subway tomorrow!

 

[baba89]

What is the unit on K?

Hi there,

Based on the information provided, it seems that the "energy transferred in" refers to the rate of heat transfer from the refrigerant to its surroundings. This can also be interpreted as the rate of work done by the paddle wheel in transferring energy to the refrigerant.

The unit for K would be kW/min, as stated in the problem. This would also make sense since it is a rate of heat transfer.

Hope this helps clarify things. Let me know if you have any further questions. Good luck with your homework!