Design Concepts Of Water Systems From River Withdrawal For Cooling And

DM Water Systems

Group 4 :Hrishikesh pawale

Sravan Kumar Reddy.S

Saketh Reddy.K

Prakhar Prashant

Water• The purest available form is from water vapour in atmosphere, as rain,

snow or produced by melting of ice.

• This water on reaching the ground absorbs different types of gases from atmosphere like nitrogen, oxygen and to a lesser extent carbon dioxide.

• Other gasses like ammonia, oxides of nitrogen and sulfur etc. ,also dissolves during rain depending upon the pollution level of the atmosphere.

• Apart from this, the surface water travels to various places and catches organic matter, suspended solids etc.

Sources Of Water1. Rivers, lakes and reservoirs (surface drainage water)

2. Underground water (shallow well, deep well, springs)

3. Rain water

4. Sea water

5. Snow melting

Why Water…???

• Heat engines require cooling, to turn heat energy into mechanical energy (and then, via a turbine-connected generator, to electrical energy).

• This is an unavoidable physical principle, and is typically exploited via the Carnot cycle.

• Usually, this cooling requirement uses water.

Uses of Water in Thermal Plants

• (a) Internal steam cycle: to create steam via the energy source (fossil fuel combustion, fission chain reaction, heat exchange with deep rocks [hot dry rock geothermal] or a heat transfer fluid [concentrating solar power]) and convey it to an electricity-generating turbine, and

• (b) Cooling cycle: to cool and condense the after-turbine steam (this condensation dramatically decreases the volume of the expanded steam,creating a suction vacuum which draws it through the turbine blades), and then to discharge surplus heat to the environment.

Water Treatment In Power Plant• Pretreatment of raw water

• Filter water for softening & DM plant

• Ultra pure /demineralised water for boiler makeup/steam generation

• Cooling water system.

• Monitoring of steam/ water parameters & H.P./L.P. Dosingsystems

MAIN IMPURITIES IN WATER

1. Suspended (Macro size) -Sand, dirt, silt. This contributes turbidity raw water.

2. Colloidal -Micro size particles(1-100nm)

3. Dissolved form -Alkaline salts and neutral salts, organic matter, Alkaline salts are mainly bicarbonates rarely carbonates and hydrates of calcium, magnesium and sodium.

4. Neutral salts are sulphates, chlorides, nitrates ofcalcium, magnesium and sodium.

TYPES OF WATER IN THERMAL POWER PLANT

• Cooling water

• Boiler water

• Process water

• Consumptive water

Water Quantity Requirements

• The exact amount of cooling water required depends on:

the energy source used,

cooling technology,

plant efficiency,

ambient temperature,

and relative humidity

Water Flow Diagram

CLARIFLOCULATOR

GRAVITY FILTER

U/G STORAGE

TANK

BOILER MAKE

UP

DM PLANT

RAW WATER

DRINKING WATER

BCW MAKE

UP

SOFTENING PLANT

Water Withdrawal And Water Consumption.

Depending on the cooling strategy employed, water that is withdrawn by thermoelectric plants may be :

•mostly evaporated, or

•mostly returned to the water source.

In Once-through Cooling system, temperature rises of 10-15°C might be expected in the receiving water body which cause additional evaporation in the receiving water body

Demineralization System• The process of demineralization water by ion exchange

comprises of:- Conversion of salts to their corresponding acids by hydrogen cation

exchanger.

Removal of acids by anion exchangers.

The two exchangers are normally in series. Normally cation precedes

the anion exchanger.• For removal of Total Dissolved solids such as Ca,

Mg, Na,Cl,So4, Alkalinity, Silica etc.

Raw Water inlet

Pressure filter

Weak acid cation

Strong acid cation

Degasser tower

Degasser tank

Weak

base anion

Strong Base anion

Mixed Bed

DM Water Storage tank

DM Water supply to unit

Overview of DM Plant

References• http://www.fao.org/nr/water/aquastat/catalogues/thermoele

ctric_cooling_water_20110429.pdf• http://www.indiacore.com/bulletin/papers-tpi2/s-k-sharma-w

ater-chemistry-in-thermal-power-plants.pdf• http://bravenewclimate.com/2009/11/20/tcase6/• http://www.cea.nic.in/reports/articles/thermal/min_of%20w

ater_coal_power.pdf