Transcript Heat pump –the Energy Saving System

Heat Pump
TEAM A: CAROLINE NAKANWAGI
SUNGHEE MIN
THERMODYNAMIC
2014 FALL
Overview
What is heat pump?
:Thermodynamic principle
 How does a heat pump work?
Advantages of heat pump
Energy types used in heat pump
:Geothermal energy
Types of heat pump
THERMODYNAMIC PRINCIPLE
Use a volatile evaporating condensing fluid known as the refrigerant
Works by compressing the volatile liquid to make it hotter on the side to be warmed
→the release of pressure to the side where heat isn’t being absorbed
The below diagram shows an example of a heat pump
1) condenser, 2) expansion valve, 3) evaporator, 4) compressor.
How a Heat a Pump Works
The refrigerant when it’s in the gaseous state, it’s pressurized and then let to flow around the
system by a compressor
→This makes the vapor extremely hot and it’s cooled in the heat exchanger also known as the
condenser
→The refrigerant that has been condensed then passes through a metering device
→This leads to a reduction in the pressure of the refrigerant
→The low pressure refrigerant enters another heat exchanger
→Here it absorbs heat and boils
→The refrigerant then returns to the compressor and the cycle is repeated
 Generally the heat pump continuously cycles
through the processes of
Compression →Condensation
→ Expansion → Evaporation
 The heat pump takes heat from the environment
and channels it into a space or system which
requires heating.
COMPRESSION, CONDENSATION,EXPANSION
AND EVAPORATION
Inside the chambers of the heat pump is allowed to expand in a continuous process
:when the gas travels through the expansion valve,
the gas absorbs heat in the form of stored energy from the air, water or the ground
As the cycle continues, the gas is compressed and it releases the energy in the form of heat
The performance of heat pump is measured by the C.O.P.( Coefficient of Performance)
:the ratio of the heat pumped into the hot reservoir to the work input to the heat pump
 Heat Pumps aren’t 100% efficient
1st Therm. Law: energy can be changed from one form to another but can’t be created or destroyed
2nd Therm. Law: work can be converted to heat but the process isn’t 100% efficient
If the heat pump is doing reversible work, then the Carnot
cycle is traversed in the opposite direction
The signs of w and q in the individual segments and the
signs of w and q in the overall process are changed
 Heat is now withdrawn from the cold reservoir that is the
surroundings and deposited into the home, which is the hot
reservoir
Since this process isn’t spontaneous, work must be done
on the system to effect this direction of heat flow
 Heat pumps become less effective as the temperature of
the cold air decreases.
 Therefore, geothermal heat pumps are better
Advantages of Heat Pumps
•Saving energy and money
•Protecting environment
•No need of any maintenance
Environmental energy can be from
•Ambient Air
•Water
•Brine (Ground heat)
 What is Geothermal Energy?
• Geo (Greek for Earth) Thermal (heat)
• Temperature of Shallow Crust from 55-75 F(Upper 10 ft.)
to 14,400 (Molten Core -4000 meter to center of core)
Brief History of Geothermal Energy
• Paleo0Indians Usage Dates 10,000 years ago
•Use by Romans- Hot Spas; Hot Running Water
•Early 1800s – Yellowstone hot Spring and Hot Spring
Arkansas
•1830 1st Commercial Use; Asa Thompson
Geothermal Potentials
•Seasonal variations measurable until 10-15 depth
• At 10 meters depth the ground is approximately 1K warmer than the yearly
than the yearly average ambient temperature
• In high depth the temperature rises 2.5-4K each 100meter
• For passive cooling depths of 30-100 meters are suitable
bath in Wooden Tub for $1
 Brine Source Heat Pump
 Air Source Heat Pump
Water Source Heat Pump
A. Brine Source Heat Pump:
ground heat as the heat source
Horizontal Collector
Vertical Collector
B. Air Source Heat Pump:
air as the heat source-air /water heat pump
External Installation
Internal Installation
Air Flow in Heat pump
A sectional drawing
C. Water Source Heat Pump:
ground water as the heat source–water/water heat pump