Refrigerant-134a enters the condenser of a residential heat pump at $800 \mathrm{kPa}$ and $50^{\circ} \mathrm{C}$ at a rate of $0.022 \mathrm{~kg} / \mathrm{s}$ and leaves at $750 \mathrm{kPa}$ subcooled by $3^{\circ} \mathrm{C}$. The refrigerant enters the compressor at 200 kPa superheated by $4^{\circ}$ C. Determine $(a)$ the isentropic efficiency of the compressor, $(b)$ the rate of heat supplied to the heated room, and $(c)$ the COP of the heat pump. Also, determine $(d)$ the $\mathrm{COP}$ and the rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and $800 \mathrm{kPa}$.
Added by Jennifer S.
Step 1
The isentropic efficiency of the compressor is $80\%$. Show more…
Show all steps
Your feedback will help us improve your experience
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
A heat pump with refrigerant-134a as the working fluid is used to keep a space at $25^{\circ} \mathrm{C}$ by absorbing heat from geothermal water that enters the evaporator at $50^{\circ} \mathrm{C}$ at a rate of $0.065 \mathrm{kg} / \mathrm{s}$ and leaves at $40^{\circ} \mathrm{C}$. The refrigerant enters the evaporator at $20^{\circ} \mathrm{C}$ with a quality of 23 percent and leaves at the inlet pressure as saturated vapor. The refrigerant loses $300 \mathrm{W}$ of heat to the surroundings as it flows through the compressor and the refrigerant leaves the compressor at $1.4 \mathrm{MPa}$ at the same entropy as the inlet. Determine ( $a$ ) the degrees of subcooling of the refrigerant in the condenser, (b) the mass flow rate of the refrigerant, $(c)$ the heating load and the COP of the heat pump, and (d) the theoretical minimum power input to the compressor for the same heating load.
Adi S.
Refrigerant-134a enters the condenser of a residential heat pump at $800 \mathrm{kPa}$ and $35^{\circ} \mathrm{C}$ at a rate of $0.018 \mathrm{kg} / \mathrm{s}$ and leaves at $800 \mathrm{kPa}$ as a saturated liquid. If the compressor consumes $1.2 \mathrm{kW}$ of power, determine $(a)$ the COP of the heat pump and $(b)$ the rate of heat absorption from the outside air.
Recommended Textbooks
University Physics with Modern Physics
Physics: Principles with Applications
Fundamentals of Physics
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD