The document discusses designing a heat exchanger using an earth-coupled heat exchanger system. It describes how heat is transferred via conduction, convection and radiation. It then explains how an earth-coupled heat exchanger works, using the constant below-ground temperature to warm or cool air. Specifically, it proposes using earth tubes to transfer waste heat from bioreactors in a pharmaceutical factory to warm a nearby house during cold winter months. A diagram shows the bioreactor waste heat being collected, filtered and passed through an earth tube exchanger and into the house.

1. LOVELY PROFESSIONAL UNIVERSITY
“TRANFERMING EDUCATION TRANSFERMING INDIA”
TOPIC: DESIGN A HEAT EXCHANGER
SUMMITED TO : Dr. NILLOHIT MITRA RAY
SUMMITED BY : KRISHNA MOHAN SHARMA
REGISTRATION: 11608871/48

2. Principles of Heat Transfer
Heat is transferred to and from objects.
Such as you and your home -- via three processes:
1.Conduction
2. Radiation
3.Convection.
Conduction is heat traveling through a solid material. On hot days, heat is conducted
into your home through the roof, walls, and windows.
Heat-reflecting roofs, insulation, and energy efficient windows will help to reduce
that heat conduction.
Radiation is heat traveling in the form of visible and non-visible light. Sunlight is an
obvious source of heat for homes.
Convection is another means for the heat from your walls and ceiling to reach you.
Hot air naturally rises, carrying heat away from your walls and causing it to
circulate throughout your home. As the hot air circulates past your skin (and you
breathe it in), it warms you.
Ground-coupled heat exchanGer
Also known as earth-air heat exchangers.
A ground-coupled heat exchanger is an underground heat exchanger that can
capture heat from and/or dissipate heat to the ground.
They use the Earth's near constant subterranean temperature to warm or cool air
or other fluids for residential.
If building air is blown through the heat exchanger for heat recovery ventilation,
they are called Earth Tubes (also known as earth cooling tubes or earth warming
tubes)
What Are Earth Tubes
Earth Tubes are a passive heating and cooling technique that uses tubes that are
buried at least 6′ feet in the ground that has air passing through them and uses the
constant temperature of 50 degrees of the earth to cool and dehumidify air in the
summer and warm air in the winter before entering the building envelope.

3. They are often used as a supplement to conventional central heating or air
conditioning systems. They work best in extreme climates that have high heat in
the summers and very cold temperatures in the winters like Iowa.
Earth tubes are often a viable and economical alternative or supplement to
conventional central heating or air conditioning systems since there are no
compressors, chemicals or burners and only blowers are required to move the air.
These are used for either partial or full cooling and/or heating of facility
ventilation air. Their use can help buildings meet Passive House standards
How They Work
In the winter cold air will enter the tube and the earth at 50 degrees will warm the
incoming air before entering the house. This will especially work well with a wood
stove or fireplace because they consume lots of air when used and usually cold air
is pulled from under your doors and around your windows as well as other places
that leak air in the building envelope.
TUBE MATERIAL
• The main considerations in selecting tube material are:
Cost/Strength/Corrosion/Resistance/Durability
• Tube material has little influence on performance.
• Selection would be determined by other factor like ease of installation,
corrosion and resistance
DESIGN
o Microbial growth is usually accompanied by the release of metabolic heat
into the fermentation medium.
o Metabolic activities can generate as much as 1000 to 2000 BTU gal-1hrs of
thermal energy per 10,000 al can generate an additional 20-100 BTU gal-1H-
1.
o To maintain a constant temperature in the fermentation, heat is either
supplied or removed from the fermentation broth during the course of
fermentation.
o Heat transfer takes place in well stirred fermentation by forced convection.
o In fixed bed microbial reactor heat transfer takes place by natural convection
or phase change(Evaporation-condensation)

4. o Typically the heat transfer system will use a “jacket” to transfer heat in or
out of reactor.

5. o There is a pharmaceutical factory which have many bioreactor and all
bioreactors are releasing heat in huge amount so we are going to transfer
this all heat to warm the house which is situated near the factory because
environment is very cold (-50 degree centigrade). So we are using earth tube
exchanger to transfer the heat which are releasing from the bioreactor.
o According the figure there is bioreactor which is releasing heat in form of
stream which is collecting is tank and there is filter which will allow only to
heat to pass through the earth tube exchanger up to the house so that house
become warms in winter season and there is one window which will allow to
pass the heat into the house and we can also stop the heat which is coming
through the earth tube exchanger into the house when we do not require.
o We can also use this stream hot water for washing, shower as well as for
bath room purpose but before using this stream hot water we have to filter
this water because this hot water is coming from bioreactor there is bacterial
culture is growing so this hot water can damage our skin so we have to fist
filter the water.

6. o There is a pharmaceutical factory which have many bioreactor and all
bioreactors are releasing heat in huge amount so we are going to transfer
this all heat to warm the house which is situated near the factory because
environment is very cold (-50 degree centigrade). So we are using earth tube
exchanger to transfer the heat which are releasing from the bioreactor.
o According the figure there is bioreactor which is releasing heat in form of
stream which is collecting is tank and there is filter which will allow only to
heat to pass through the earth tube exchanger up to the house so that house
become warms in winter season and there is one window which will allow to
pass the heat into the house and we can also stop the heat which is coming
through the earth tube exchanger into the house when we do not require.
o We can also use this stream hot water for washing, shower as well as for
bath room purpose but before using this stream hot water we have to filter
this water because this hot water is coming from bioreactor there is bacterial
culture is growing so this hot water can damage our skin so we have to fist
filter the water.