Question

A 500W refrigerator (uniform pipe area of 100 cm2 ) uses R-410A, which goes through the followings: Ignore gravity and heat loss during transportation.

(a) What is the mass flow rate? (Note: m = V/v. Try graphing your continuity equation as a function of
(b) What is QH for 100 s of operation?
c) What is QL? for 100 s of operation?
(d) What is the flow speed before and after the expansion valve?
e) What are the coefficient of performance of cooling and heating? [3 Pts]

Answer 1

The mass flow rate can be calculated using the continuity equation. The heat transfer rates QH and QL can be calculated using the formula Q = mcΔT.

Step-by-step explanation:

To calculate the mass flow rate, we can use the continuity equation, which states that the mass flow rate (m) is equal to the product of the density (ρ) and the velocity (v) multiplied by the cross-sectional area (A) of the pipe.

So, m = ρAv.

To calculate QH for 100 s of operation, we need to know the heat transfer rate. The heat transfer rate (Q) can be calculated using the formula Q = mcΔT, where m is the mass flow rate, c is the specific heat capacity of the refrigerant, and ΔT is the change in temperature.

QL can be calculated using the same formula Q = mcΔT, but with different values for the temperature difference and specific heat capacity.