1. Lecture # 7 Min soo Kim Mechanical & Aerospace Engineering
Environmental Thermal Engineering
Lecture # 7
Min soo Kim
Mechanical & Aerospace Engineering

2. Operating characteristics and Application of Heat pump systems

3. Heat Pump Cycle
Heat absorption from cold reservoir and heat transport to
hot reservoir
Same organization with existing refrigerating cycle
Use for both heating and cooling
Highly economical in initial installation cost and space
Switch the role of indoor and outdoor heat exchanger by changing the flow direction depending on operation purpose(heating, cooling)
Use four way valve in order to change flow direction

4. Compare Energy Flow Diagram
Electric Heating instrument
Boiler
Heat Pump

5. Compression Heat Pump for heating and cooling
Outdoor unit
heat exchanger
Accumulator
Compressor
Motor
Oil-separator
4-way Valve
Bypass Valve
Expansion Valve
Indoor unit
Heating Mode
Cooling Mode

6. Heat Pump Classification(1)
The method of heat pump classification
1) Heat source and sink
2) Transfer medium of heating and cooling energy
3) The form of building structure
4) Size and appearance
Heat source of heating heat pump
Air, well water, groundwater and geothermal, solar
and other natural heat source, waste heat coming
out of swimming pool, commercial building, etc.

7. Heat Pump Classification(2)
Heat source and sink
Distribution fluid
Thermal cycle
schematics
Air
Refrigerant changeover
Water

8. Heat Pump Classification(3)
Heat source and sink
Distribution fluid
Thermal cycle
schematics
Water
Water changeover
Ground-coupled
Air
Refrigerant changeover
Ground-source, Direct-expansion

9. Heat Pump Operating Characteristics(1)
Heating capacity and load of heat pump depending on the change of outdoor temp.

10. Heat Pump Operating Characteristics(2)
Outdoor temp. drop
1. Less heat pump capacity than required heating load
i) Use additional heating equipment Reduction in overall
efficiency of heat pump
ii) Use large heat pump or inverter
2. Frost formation on the surface of outdoor coil
: decrease in heating capacity, causing the liquid refrigerant to compressor
Prevent decline of efficiency and heating capacity by increasing the temp. of evaporator using waste heat, river water, well water, etc.

11. Heat Pump Operating Characteristics(3)
Heat pump performance depending on outdoor temp.
Capacity (103 Btu/hr)
Air Temperature (oF)
Power (kW)
Air Temperature (oF)

12. General Vapor Compression Heat PumpQH
High pressure liquid
High pressure
High temperature
vapor
Condenser
Compressor
Expansion
device W
Low pressure
Low temperature
Mixture of liquid & vapor
Evaporator QL

13. Thermodynamics in Heat Pump
Indoor supply heat= Outdoor heat + Compressor electrical work
COP of heating mode = heat effect and input power proportions
COP of heating mode = heat effect and overall electrical input power proportions
COP of cooling mode

14. COP of Cooling Mode Capacity & COP Operation mode
Heat absorbed by evaporator
Work input to compressor
Heat rejected by condenser
COP
Heating
Cooling 1
0.3
1.3
4.3
3.3

15. Economics on Heat Pump Operation(1)
Annual residential heating load
Total electric energy required for heat pump
Power plant efficiency
Hot air furnace plant efficiency
Amount of resources required for heat pump
Amount of resources required for hot air furnace
If Power plant efficiency is 0.35 and Hot air furnace efficiency is 0.85, Cop is higher than 2.4

16. Economics on Heat Pump Operation(2)
Electric charge
Fuel cost per unit calorie
Heat pump operating cost < Hot air furnace operating cost

17. The world Heat Pump Operating Temp. Range
Zone 1 : year round cooling Twinter ≥ 20℃ Tsummer ≥ 20℃
Zone 2 : heating and cooling Twinter ≥ 0℃ Tsummer ≥ 20℃
Zone 3 : cooling in summer Twinter ≤ 0℃ Tsummer ≥ 20℃
Zone 4 : heating in winter Twinter ≥ 0℃ Tsummer ≤ 20℃

18. Gas Engine Driven Heat Pump
Background of Development
Promote the use of alternative
energy
Efficient use of energy Suppress the power consumption in summer Averaging annual load of gas and
electricity
Patterns of consumption of gases & electricity (2005’)
Power MAX.(MW)
Gases
(thousand.toe)
Gas Engine Driven Heat Pump
Drive compressor driven using gas engine
Increase system efficiency by waste heat recovery Supplement the heating capacity decreases using waste heat depending on outdoor temp. decrease
Defrost operation is not required and start-up characteristic is
fast in heating mode
Fuel diversification, low NOx Tue, small size, low noise, etc. is
required.

19. Gas Engine Driven Heat Pump
Cooling and Heating Cycle of Air-preheating GHP system

20. Solar Heat Driven Heat Pump
Solar heat is usable only in daytime, so heat storage tank is needed.
When we use solar heat collector as a radiator at night, cooling mode is possible.
Composed of compressor, storage tank and solar collector

21. Solar Heat Driven Heat Pump
Heating Cycle
Cooling Cycle

22. Solar Heat Driven Heat Pump
NASA contract NAS-97113, Johnson Space Center
Synopsis: Variable Speed Solar Photovoltaic Heat Pump Compressor. Proof of concept to demonstrate a solar heat pump for advanced missions such as a lunar missions while at the same time, promoting commercialization of the technology for terrestrial applications.

23. Stirling Engine Driven Heat Pump
High heat-efficiency Possible to use different kinds
of fuels and heat sources Low problems of emissions,
noise and vibration
Resolve matters
Regenerator efficiency increase Reliability secure of piston

24. Stirling Engine
Schematic representation of the Stirling cycle in 4 steps:
1. The piston rises, the working gas is compressed. 2. The gas is displaced from the cold chamber to the hot chamber, the pressure increases further. 3. The piston falls, the gas is expanded. 4. The gas is displaced from the hot chamber to the cold chamber, the pressure decreases further.

25. Application of Stirling Engine
Stirling-Rankine Fuel-Fired Heat Pump

26. Heat Pump using Heat Storage
Fig. heating and cooling heat pump using heat storage

27. Heat Pump using Heat Storage

28. Lab Activities Multi-type Heat pump

29. Multi Type Heat Pump System
The increasing demand for home HVAC
Multi type HVAC
One outdoor heat exchanger
Several indoor heat exchanger
Multi type heat pump system
Saving cost and space
Summer : Cooling systems
Winter : Heating systems
The problem of the complexity of the system and
the capacity control

30. Multi Type Heat Pump for Building
Outdoor Heat Exchanger
Refrigerant Pipe
Indoor Heat Exchanger

31. Advantages of Multi Type Heat Pump for Building
Building Purpose
Advantages
A building for rent
-Individual response to each residential room.
- Clarification of residential air-conditioning usage fees.
A office building
-Respond to the loads from Small rooms (living room, conference room, etc.) to large rooms (longer serve space).
-Economical Driving
-Respond to the requirement of cooling and heating from Perimeter and interior zones.
A intelligent building
-Annual cooling respond to communication and OA equipment
-Respond in case each room and store need cooling and heating at the same time.
Hotel
-Individual respond to each zone depending on different load characteristics.
Hospital
-Individual control of hospital room, nursing room, etc.
Shopping center
-Individual control of each store when business hours are different .

32. Schematic Diagram of Heating and Cooling Multi Type Heat Pump
Indoor unit
Service Valve
Outdoor unit
Indoor unit
heat exchanger 1
Bypass Valve
4-way Valve
Oil-separator
Indoor unit
heat exchanger 2
Compressor
Accumulator
Outdoor unit
heat exchanger
Service Valve
Expansion Valve
Motor
Indoor unit
heat exchanger 3
Accumulator
Heating Mode
Cooling Mode

33. Multi Type Heat Pump – Foreign Country
Sanyo: 97’ Attempt new refrigerant
to multi type air conditional Eco Multi System
Daikin: Super Multi Plus product
Mitsubishi Electronic: Y, R2 and WR2 series
Toshiba: Super Multi product for R407C
and R22

34. Multi Type Heat Pump – in the country
LG Electronics
Capacity - Cooling - 1unit(A)
11,000Btu/hr
Capacity - Heating - 1unit(A)
Capacity - Cooling - 2unit(B1+B2)
18,000Btu/hr
Capacity - Heating - 2unit(B1+B2)
Capacity - Cooling - 1unit(B1 or B2)
9,000Btu/hr
Capacity - Heating - 1unit(B1 or B2)
12,000Btu/hr
Capacity - Cooling - 2unit(A+B1 or B2)
20,000Btu/hr
Capacity - Heating - 2unit(A+B1 or B2)
23,000Btu/hr
Capacity - Cooling - 3unit(A+B1+B2)
29,000Btu/hr
Capacity - Heating - 3unit(A+B1+B2)

35. Lab Activities CO2 Heat pump

36. CO2 Refrigerant Advantages
Not toxic, odorless, non flammable, non explosive
GWP : 1
ODP : 0
High refrigerating capacity, low compression ratio
Possible to weight lightening and low cost
Disadvantages
Low critical temp.(31 ℃), high operating pressure

37. Refrigerant properties
For A/C & heat pump application

38. CO2 Heat Pump System
P-h diagram for R134a and CO2

39. CO2 Heat Pump System

40. Heat pump for a hot water heater
Fig. CO2 heat pump water heating cycle

41. Heat Pump Instances
DENSO

42. Heat Pump Instances
HINOMARU CORPORATION
SANYO
DAIKIN
MITSUBISHI

43. The Current State of Air-conditioning and Refrigerating Industry
Figure: Worldwide air conditioner market conditions (’99) – 1million

44. The Characteristics of Air-conditioning and Refrigerating Industry
Electron
Medicine
Environment control in semiconductor industry
Clean room
MRI
Fiber
Isothermal-isohumidity in fiber industry
Air-conditioning
and Refrigerating
Industry
Food
Food storage
Food processing
Frozen storage
Machine
Architecture
Heat treatment in metal industry
Measuring device cooling installation
Heating and cooling
equipment for office
Ventilating equipment
equipment for Home
Chemistry
Freeze drying
Refrigeration and liquefaction of chemical processes