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2. Environmental impact and Economics
benifet of binary cycle power plant
Geothermal Energy
Extraction & Uses
Introduction to binary cycle
Geothermal Reservoirs
Differents between dry steam,flash
steam,and binary cycle power plant
ORC and Kalina cycle
3. What is geothermal energy?
Geothermal energy- energy that
comes from the ground; power
extracted from heat stored in
the earth
¤Geo: earth
¤Thermal: heat
4. GEYSER
RESERVOIR'S CAN BE SUSPECTED IN THE AREAS
WHERE WE FIND :-
BOILING
MUD POT
VOLCANO HOT
SPRINGS
5. Testing the soil
Analyzing underground
temperature
• The rising hot water & steam is trapped
in permeable &porous rocks to form a
geothermal reservoir.
•
6.
7. • Hot springs, used as spas.
• Heating water at fish farms.
• Provide heat for buildings.
• Raising plants in greenhouses,
drying crops.
• Provides heat to industrial
processes
10. • Steam plants use hydrothermal fluids
that are primarily steam.
• The steam goes directly to a turbine,
which drives a generator that
produces electricity. The steam
eliminates the need to burn fossil fuels
to run the turbine.
• This is the oldest type of geothermal
power plant.
• It was first used at Lardarello in Italy in
1904. Steam technology is used today
at The Geysers in northern California,
the world's largest single source of
geothermal electricity.
• These plants emit only excess steam
and very minor amounts of gases.
11. • Hydrothermal fluids above 360°F
(182°C) can be used in flash plants
to make electricity.
• Fluid is sprayed into a tank held at a
much lower pressure than the fluid,
causing some of the fluid to rapidly
vaporize, or "flash." The vapor then
drives a turbine, which drives a
generator.
• If any liquid remains in the tank, it
can be flashed again in a second
tank (double flash) to extract even
more energy
17. • The first geothermal binary power plant was put into operation at Paratunka
near the city of Petropavlovsk on Russia’s Kamchatka peninsula in 1967.
• It was rated at 670 kW and served a small village and some farms with both
electricity and heat for use in greenhouses.
• Nowadays, binary power plants are used commonly throughout the world.
Currently, the total installed power worldwide of geothermal binary power
plants is about 700 MWe, representing about 8% of the geothermal power
installed worldwide
18.
19. • The geothermal reservoir's hot in-situ fluid (or geofluid) is produced to the
surface via a wellbore, if necessary assisted by a pump. On the surface, the hot
geofluid transfers some of its heat to the secondary cycle, via a heat exchanger,
thus cooling in the process. The cold geofluid is then reinjected into the
geothermal reservoir via a separate wellbore, where it is reheated.
• The primary cycle is considered an "open" cycle.
20. • Cold high-pressure working fluid is heated and vapourised in a heat exchanger
by the hot geofluid. The hot high-pressure vapour is expanded in a turbine
before being cooled and condensed in a condenser. To close the loop, the cold
low-pressure liquid is repressurised via a feed pump.
• The secondary cycle is a closed cycle.
• The two main secondary cycle configurations are
Organic Rankine cycles (ORC)
Kalina cycles
21. • In 1961, Harry Zvi Tabor and Lucien Bronicki developed a method for utilizing a low
boiling temperature organic fluid as the working medium to power turbines for
electrical generation. Electrical power is usually generated in processes based on the
Rankine cycle with water as a working fluid.
• An organic Rankine cycle (ORC) system, using an organic fluid instead of water as the
working fluid, is potentially feasible in heat recovery systems and is particularly
favorable in low-temperature applications.
• Also, ORCs enable cost-efficient power generation from low-grade heat sources by
replacing water with organic working fluids such as refrigerants or hydrocarbons.
22. • Organic working fluid with a low boiling point evaporates and develops enormous
pressure sufficient to drive the turbine. In this respect, the economic, environmental,
and operating performance of the ORC depends on the properties of the working
fluids as well as the design and operating characteristics of the cycle.
• These systems consist of an evaporator (heating area), turbine, and condenser
(cooling area). There are several advantages to using ORC low-grade geothermal
resources, including economical utilization of energy resources, smaller systems, and
reduced emissions of CO, CO2, NOx, and other atmospheric pollutants. The main
advantage of the ORC is its superior performance in using geothermal heat with a low
temperature.
. Which is organic fluid?
23. • The technology is the creation of Dr. Alexander Kalina, a Russian scientist.
• The Kalina cycle is principle a modified Rankine cycle.
• It uses a working fluid comprised of at least two different components, typically
water and ammonia.
• Ammonia-water mixture improves system thermodynamic efficiency and provides
more flexibility various operating conditions.
• As plant operating temperatures are lowered the relative gain of the Kalina cycle
increases in comparison with the Rankine cycle.
24. • The pump pressurized the saturated liquid (5) which is leaving
from the condenser and it is sent in to the high temperature
recuperator (6).
• The liquid takes off the heat from the two phase dead vapour
(3).
• The pressurized hot liquid (sub-cooled state) enters (1) into the
vaporizer where the liquid is converted in to vapor (2) by
utilizing the latent or sensible heat of the hot source (1s-2s).
• The saturated vapor (2) from the vaporizer is expanded in the
turbine up to its condenser pressure.
• The two phase mixture after giving a part of it's latent heat to
the incoming liquid (4) enters in to the condenser, where
cooling water enters (lw), takes away all the heat available in
the two-phase mixture, and leaves at higher temperature (2w).
• The saturated liquid is pressurized in the pump and the cycle
repeats.
25. • Generate 10%-50% more power than conventional steam power generation
technologies.
• Have lower capital costs due to smaller heat exchanges and no heat transfer oil
loop.
• Are unmanned or minimally supervised and have lower plant auxiliary loads.
• Lower demands for cooling water and cooling infrastructure.
• Minimal downtime for maintenance.
26. The secondary working fluid plays a key role in the cycle, so the
selection of working fluid affects considerably system
performance. Whereas there are many available working fluids,
there are several general criteria while selecting the proper
working fluids. Stability, non-fouling, non-corrosiveness, non-
toxicity, and non-flammability are a few preferable physical and
chemical characteristics
27. The critical point of a working fluid suggests the proper operating temperature
range for the working fluid of liquid and vapor forms, and the critical temperature
is important data for fluid selection. The critical temperature should be higher
than the maximum cycle operating temperature. Working fluids that have low
boiling points must be chosen for binary plants. These fluids enable them to
obtain vapor at low temperatures.
• DENSITY
• LATENT HEAT
• LIQUID HEAT CAPACITY.
28. The viscosity of the working fluid should be maintained low in both liquid and vapor phases in
order to achieve a high heat transfer coefficient with reduced power consumption. Similarly, the
thermal conductivity must be high so as to achieve high heat transfer coefficients in both the
employed condensers and the vaporizers.
Some substances, mainly refrigerants, deplete the ozone layer or/and contribute to global warming.
Because of their negative effects, there is a necessity to choose those with less harmful effects on the
environment. ODP values of substances indicate their ozone depletion potential. Similarly, GWP
values of substances indicate their global warming potential. Candidate working fluids for the binary
cycle should have low ODP and GWP in case of leakage.
The working fluids are expected to be non-toxicity and non-flammability. Yet, they are not
always practically satisfiable or critically necessary. Many substances, like R-601, are
considered flammable, but this is not a problem whether there is no ignition source around.
The stability and compatibility of the working fluid are of great importance to not to affect
negatively the system components by reacting with them or by undamaging to them.
29.
30. • Refrigerants must not cause harmful environmental impacts like ozone layer depletion and climate
change. The environmental impacts of refrigerants are mainly their ozone depletion potential.
• The ozone layer is a layer in Earth’s atmosphere containing relatively high concentrations of ozone
(O3).
• Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life
because it absorbs biologically harmful ultraviolet (UV) radiation coming from the sun.
• Refrigerants containing chlorine and/or bromine atoms like halo carbon refrigerants lead to ozone
layer depletion. The chemical is extremely stable, which is a desirable feature for a refrigerant, but
when released into the atmosphere, it ultimately diffuses to the upper atmosphere. In the upper
atmosphere, it breaks down, and the chlorine combines with the ozone that exists there, depleting
the ozone concentration.
31. • A material’s ozone depletion potential is a measure of its ability, compared
to CFC-11, to destroy stratospheric ozone .
• Another environmental impact is the causation of the global warming.
Halocarbon refrigerants also can contribute to global warming and are
considered greenhouse gases.
• The global warming potential of a greenhouse gas is an index describing its
ability, compared to CO2 (which has a very long atmospheric lifespan), to
trap radiant energy. The GWP, therefore, is connected to a particular time
scale (e.g., 100 or 500 years). For regulatory purposes, the convention is to
use the 100-year integrated time horizon (ITH)
32. Capital Cost Estimate:-
The base cost estimate for this
technology case totals $2521/kW.
This price is dependent on the
technology used, reservoir
temperature, and location of the
power plant.
33.
34. Operations & Maintenance Costs:-
Binary cycle geothermal plants are able to maintain the turbine (turboexpander)
at a lower cost than other geothermal technologies due to the increased quality
of the working fluid compared to the geothermal steam that passes through the
turbine in dry steam and flash plant designs.
What binary cycle plants save in turbine maintenance is lost in the additional
pump maintenance since the other technologies do not require downhole
pumps.
Additionally, for binary cycle plants to produce equivalent net power outputs,
they require higher flow rates from the production wells and have more overall
pumps and piping compared to the other geothermal technologies.
35.
36.
37. • Resource and Location: -
⚬ There is only a small percentage of land that lies above suitable pockets of
water and steam that can heat homes or power electrical plants, limiting the
possibility of installation of geothermal power plants.
⚬ Many other places that are potential for providing geothermal energy are
extremely tectonically active, which makes it hesitant to install the large-
sized electricity generating power plant
38.
39. • Infrastructure and Costs: -
⚬ By nature, a geothermal energy source could only be used to produce the baseline power
for an electrical grid which causes problems in and of itself.
⚬ Equipment for drilling wells and setting up power plants is extraordinarily expensive and
training people to staff a geothermal power plant is time consuming and costly.
⚬ Once the energy is extracted form the underground wells, it cannot be transported to a
different facility whose grid is more in need, it has to be used as it is extracted.
40. • More Environment-friendly than conventional sources
• Hot reservoirs inside the Earth are naturally replenished, making it both
renewable and sustainable
• Dry plants and flash plants use the geothermal brine to directly power the
turbines. Therefore, they cannot be utilized for lower-temperature resources.
Binary plants can exploit low temperature fluids, so can be used in more
widespread applications.
• In dry steam or flash steam power plants, small amounts of greenhouse gases
and pollutants that are naturally present underground will be released into
the atmosphere during extraction. On the other hand, in binary steam power
plants, carbon emissions can be limited to zero since the steam does not
directly come from underground.
41. • It is location specific
• It will also lead to risk of triggering earthquakes
• Despite being considered a sustainable and renewable energy, the chances
are that specific locations might cool down after time, making it impossible to
harvest more geothermal energy in future
• The only non-depletable option is sourcing geothermal energy right from
magma but the technology for doing so is still in the process of development.
• Their costs of construction is very expensive, that concerns exploration and
drilling. They also require specially developed heating and cooling systems, as
well as other equipment that can withstand high temperatures