Page 54 - Low Temperature Energy Systems with Applications of Renewable Energy

42 Low-Temperature Energy Systems with Applications of Renewable Energy

S _ entropy rate
T temperature
V velocity
W, W _ work, power
x quality

Greek letters

h efficiency
l thermal conductivity
r density

Subscripts

A ambient
AR absorption refrigerator
C carnot
c, CN condenser
CP compressor
ds desuperheater
EV evaporator
H high
HP heat pump
L low
R refrigerator
TH throttle
0 dead state

Review questions

1. What value determines the thermodynamic perfection of the heat pump operation?
2. What data are the starting points for calculating the cycles of heat pump plants?
3. How is the efficiency of the cycle point operation in the heat circuit of a heat pump
evaluated?
4. How is the cooling agent for the heat pump selected?
5. How are the cooling agents divided according to ozone safety?
6. What are the criteria for ozone safety and heat exposure?
7. World trends in the application and development of heat pump plants.
8. What are the main principles of legislation on energy saving?
9. What is energy management?
10. Discuss the purpose and main stages of energy audit.
11. Describe the thermodynamic bases of heat pump operation.
12. Describe some sources of low-potential heat.