NETRA

Technology

PROJECT COMPLETED:

INTRODUCTION:

In desalination, there are four types of process which are commercially available i.e. Multi-Stage Flash (MSF) desalination, multiple effect distillation (MED), MED with Vapor Compression (VC) and reverse osmosis (RO) or membrane based desalination. The major difference between these processes consists of their different input energy requirements. For MSF, MED and MED-VC the input is ‘thermal energy’ which could be steam or hot water. For RO or membrane based desalination the input energy is ‘electrical energy’.

DEMONSTRATION PLANT:

NETRA has developed, designed and setup a 1,20,000 LPD ‘Flue Gas based Sea Water Desalination (FGSWDeSal) plant at Simhadri. This plant is first of its kind in India and is in successful operation since February 2017. Salient details of the FGSWDeSal is as under

a) Capacity of Plant: 1,20,000 LPD
b) Thermal Rating of Plant: 500 kW-Th (approx)
c) Technology: (i) Desalination: Multi Effect Distillation; (ii) LP Steam: Flash Steam Generator in conjunction with Flue Gas Heat Exchanger
d) Plant Input: (i) Waste Flue Gas from ID Fan outlet; (ii) Hot CW from condenser outlet; (iii) Cold CW from condenser inlet
e) Gain Output Ratio (GOR): ≥ 6
f) Output Quality: TDS > 5 ppm
g) Foot Print: 250 sq.mtr (approx)

Process Improvement and Design

INTRODUCTION:

Computational Fluid Dynamics (CFD) is a simulation tool used for visualizing system/process/equipment parameters through-out the domain. In CFD, an exact geometrical model (1D, 2D or 3D) of the process/equipment is created and divided into very small cells in which process equations are solved. Process equations are to be solved for each cell using numerical methods, for which large computational resource is required. Once solved and validated, CFD model provides a continuous visual profile of all the process parameters. A validated CFD model is like having data from thousands of sensors for each of the process parameters.

A validated CFD model is powerful tool to understand the process and its inherent abnormality and can be used to evaluate the effect of any modification or design changes in the process and before actual implementation. Presently, with high computational power being available, CFD modeling is being used to develop design and processes from conceptual stage to final specifications.

BENEFIT

Benefit accrued in some of the NTPC stations where CFD recommended modifications have been carried out are listed in the following Table

SNo.StationModification carried inBenefit

1

TandaFG DuctReduction of ID Fan Power by 100 KW/Unit

2

Kahalgaon St-IFG DuctReduction of ID Fan Power by 120 KW/Unit

3

Simhadri St-IFG DuctReduction of ID Fan Power by 350 KW/Unit
4Simhadri St-IIFG DuctReduction of ID Fan Power by 330 KW/Unit
5Ramagundam ST-IIESP InternalReduction in SPM by 100 mg/Nm3
6Ramagundam ST-IIESP InternalReduction in SPM by 100 mg/Nm3

Biomass-in-Dadri

INTRODUCTION:

The practice of residual crop burning by the farmers in the winter season causes severe smog in Delhi-NCR region. The reason that the farmers burn crops is that the crop residue is of no value to them and burning this residue appears as quick and cost-effective option to get rid of the waste. In the recent years, this problem has only multiplied and the air quality is getting worse. As per estimates, in the case of Punjab and Haryana, every year around 30 million tons of crop residue is burnt in the field which causes the sever smog and air pollution in nearby regions and Delhi NCR every year mainly at the end of October. As a solution to this problem, NETRA carried out a complete characterization of biomass related to its handling, milling, combustion and ash deposition. The recommendation generated out of this was used to develop a “Standard Operating Procedure” based on which series of co-firing trials was carried out in Dadri U#4.

TECHNOLOGY BRIEF

Co-firing of biomass in existing PC fired Boiler provides an alternate solution to the farmers by providing them an economic value to their farm residue. Biomass is considered a “carbon Neutral” fuel. Co-firing of biomass not only helps in preventing air pollution due to burning of farm-residue but also reduces the carbon emission from the PC fired plant. In this technology biomass pellets are fed over a specifically selected coal conveyer and fed into identified bunker/s. The blend of biomass and coal is milled in the existing milling system and fired into the boiler. One has to specifically identify the feeding mechanism, mill operating temperature and blending ratio and assess the combustion and ash deposition characteristics of the biomass for successful co-firing of biomass in the existing PC fired Boiler

Actual implementation in Dadri U#4:

a. Co-firing field trials were carried out in Dadri U#4. The co-firing process happened as predicted. Upto 7% biomass was co-fired with four mills (B, C, D, E) at full load of the boiler.

b. It was observed during the biomass co-firing that due to low mill temperature; the mill power was higher by 78-150 KW and the flue gas temperature was higher by 5-7 deg as compared to 100% coal firing. There is slight decrease in boiler efficiency (0.2-0.3%) The ash elemental analysis during the co-firing indicate no major change in elemental composition.

c. This was in line with the recommendation given based on detail combustion, handling, milling and ash deposition characteristics carried out at NETRA.

Generator Stator Overhang Winding Vibration

INTRODUCTION:

The stator winding insulation system of generator on service is exposed to a combination of thermal, electrical, environmental and vibrational stresses. Stator bars in slot are subjected to a certain electromagnetic force resulted by interaction of the stator current and rotary magnetic field, as well as mechanical forces transmitted via the core and bearings at rotational speed what would make the bars into vibration. The electromagnetic force applied on the stator winding is 100Hz (or twice line frequency) alterative force. When the vibration frequency of the stator bars equal or close to 100Hz, the resonance of stator bars will occur. This resonance will cause high amplitude of vibration. The vibration makes the bar loosening, fatigue cracking of conductors and abrades the slot conductive of insulation. After that, slot discharge may occur across the air gap between the core iron and the bar surface, which is a common failure mechanism of stator winding insulation. At the generator end windings, high vibration lead to rubbing between the two surfaces i.e. coil to coil or coil to support which results in serious damage to stator insulation which require extensive out-of-service repairs. Some turbine generator stator windings have apparently failed due to a vibration of stator bars.

STRENGTH OF TECHNOLOGY

a) These sensors are Fiber Optic based, therefore, these sensors do not  have any constrain for mounting location & can be directly mounted on end winding.

b) These sensors are indigenously built & cost effective to commercially available sensors

c) These sensors are non-conductive & immune to EMI noise.

TECHNOLOGY BRIEF

Fiber grating is made by periodically changing the refraction index in the glass core of the fiber. When a light beam is sent to an FBG, each segment reflects a specific frequency of light depending upon the FBG design, called the Bragg wavelength, while transmitting all others. Any changes in strain and temperature affect both the refractive index and grating period which changes bragg wavelength which is corresponding to vibration.

INTRODUCTION:

The uncertainty in the conventional power sector is introduced mainly due to volatile nature of the consumers towards their power consumption and intermittency in the penetrated renewable energy resources. Previously load volatility was the only challenge in front of the power engineers and that has been easily sorted either by ramping quality of the thermal generators or by performing load curtailment at the load side. Addressing variability and uncertainty of renewable generation necessitates additional operational flexibility from various resources. It is estimated that by 2022, Indian grid with 175 GW of RE will requiring ramping rate to the tune of 32 GW/Hr and will be a challenge to achieve considering present regulatory system and system approach until drastic steps in forward direction are adopted. Thus the modern power sector needs solutions which can make it adaptive against any dynamic/sudden changes or in other words which can make it flexible.

Improving flexibility of unit over the designed flexible operation, requires either integration of advance control solution or mechanical modification of the system depending upon the quantum of flexibility required. This chapter describes innovative control solution of Condensate Throttling System(CTS) integration in existing DCS along with unit control module in U#6 of Dadri to improve unit primary frequency response (PFR) and ramp rate.

DEMONSTRATION PROJECT:

NETRA has implemented this project of integrating CTS solution and Unit control module in existing DCS of Dadri U#6 with following key steps.

1. Assessment of Unit capacity for providing PFR and Ramp rate

2. Unit assessment for anticipated benefit with retrofitting flexible control

a. Condensate Throttling Testing to determine margin and response

b. Boilers firing response testing to assess present operating condition

c. Speed & size of steam storage assessment to determine present margin for PFC

3. Preparation of design document

4. Implementation at site and testing

The integration philosophy was to have this solution on operator wish with bump-less. More than 400 operating parameter/status were mapped for processing and providing required control to implement the solution over MODBUS protocol. Hotwell level alarms/switch values were reworked as per the requirement and The project was completed in July-2017 with significant improvement in unit PFR and ramp rate.

Power-Stations

INTRODUCTION:

With the power systems becoming more and more complex, the fault levels in the system are going up. This has resulted in focusing greater attention to the healthiness of earthing system. The efficacy of an earthing system depends on various factors like resistivity of soil, duration & magnitude of fault and the maximum safe current that a human body can tolerate i.e. 116 mA for 1 sec (for 50 kg body weight) as per IEEE 80-2000. So, it is significant to do proper analysis and calculation of earthing system parameters i.e. step & touch potential, ground resistance, grid integrity etc. Once these parameters satisfy the safety requirements, the earthing system is considered adequate.

i) Older Stations: Existing earthing system adequacy in view of increasing fault level

ii) New stations: Check the grid integrity and implementation of earthing system as per design

BENEFITS OF EARTHING ASSESSMENT:

i) Earthing assessment required for safety of assets and live stock

ii) It will help in design validation & benchmarking

iii) Assess the present earth grid condition for older stations

iv) Review the present practices/workmanship during erection for new stations

v) Reference for future assessment and determination of corrective actions

INTRODUCTION:

Power System Stabilization (PSS) is a device that enhances the damping of low frequency oscillations at the synchronous machine by controlling excitation. As a benefit of the action of several PSSs at several synchronous machines, the stability of the whole power system increases. As per IEGC, installation of PSS and its periodic tuning is mandatory. Importance of a tuned PSS increases during Grid disturbances. PSS Tuning now being monitored by RPCs. Further, it has been generally observed that our 500MW Units having BHEL machines with brushless excitation system & DVR are not producing enough or appreciable damping through PSS action when step test is carried out.

Stabilizer-Tuning

DEMONSTRATION PROJECT

i) In NTPC, PSS tuning is normally carried out with the help of OEM by taking the response through step test. However, optimum response is not possible to achieve by this approach and thus PSS response verification test is only carried and it cannot be considered as optimum.

-Attainable touch potential < Tolerable touch potential

ii) In practice, effective optimization of PSS response is a complex process and not possible without modelling studies & computer simulation. Values of various Gain settings / parameters of AVR & PSS derived through simulation studies are adopted in actual system. Actual System Response or oscillations are then analysed and further simulation studies are carried out to arrive at the optimum setting / gains.

iii) The study was carried out to perform optimum tuning of the Power System Stabilizer operating at 490 MW, 21 KV, 50 Hz synchronous generator in NCTPP ST-II DADRI (unit no 6). The outcome of the analysis was expected to be the optimum PSS parameters settings together with expected performance presentation. Finally proposed settings was to be adopted in the AVR and measurements to be performed to verify simulations. Dynamic performance of the AVRs with PSS for the analyzed generator set was validated using dynamic modelling and time domain simulation. PSS settings were elaborated based on frequency responses of linearized model, taking into account generic rules for PSS tuning. Performance of the AVR with PSS was verified by means of eigenvalue calculations and time domain simulations. DIGSILENT Power Factory software was used in the study.

Loop Control

INTRODUCTION:

Part load operation has introduced regime of auxiliaries unable to run at their best efficiency/design operating point. Power plant by design itself has numbers of flow regulating devices such as valves, damper, guide vane to meet varying process requirement. Retrofitting Variable Frequency Drives (VFD) Facilitates speed regulation of induction motor thus variable speed operation of Fan/Pump to meet variable process requirement and thus enable migration from throttling mechanism. VFD retrofitting also facilitates smooth motor starting thereby less stress on the mechanical components which further helps in saving maintenance cost and increased availability. VFD retrofitting essentially involves catering motor reliability issues, matching control philosophy and space requirement. Retrofitting being the case, compel to refurbish the existing motor instead of usually higher frame size inverter duty motor for addressing the motor reliability issues i.e. thermal and dielectric stresses. This chapter describes retrofitting of VFDs in Cooling tower fan motors for close loop operation depending on unit load and ambient conditions.

SOLUTION BRIEF:

VFD environment of fast rising repetitive voltage pulses is very challenging in terms of Di-electric and thermal stress to the motors (especially random wound LT motors) thus usually requires use of inverter duty motor, very often of higher frame size, posing space constraint, alignment and other related problems during retrofitting. In case of retrofitting in existing motors the insulation and thermal scheme needs to be reviewed and addressed to meet the requirement. Thermal stress in case of load like CT fan which follow square Torque-Speed characteristics, is not an issue as Cu Losses reduce much faster compare to the cooling effect reduction by motor fan. For insulation upgradation dual coated magnet wire with Nomex composite paper based insulating paper used

BACKGROUND

  • Bulk fly ash utilization initiative
  • Presently, NTPC generates around 60 million tons of coal ash annually from its coal based thermal power plants with an ash utilization of 53.65 %. There is a growing need to achieve the target of mandatory 100% utilization of fly ash over a specified time span as per Gazette Notification issued by MOEF, GoI

POSSIBLE SOLUTION:

  • Geopolymer concrete, eco-friendly construction material, has emerged as important engineering materials in recent times because of its utility in developing ecologically sound and sustainable construction materials. It will contribute not only to enhance fly ash utilisation but also producing valuable carbon off-set credits.

SHORTLISTED SOLUTIONS:

  • Construction of M40 grade trial patch of 50-meter single land and 100-meter double lane at CBRI Roorkee and NTPC Dadri respectively.

SHORTLISTED SOLUTIONS

  • IRC accreditation – Findings of the study were presented before Highway Research Board of Indian Road Congress(IRC) and IRC accreditation has been granted. IRC has accredited ‘Geopolymer concrete’ for road construction developed by NETRA – NTPC Ltd. On dt 05.01.2018.

Tangible/Intangible Benefits:

  • Fly ash utilisation 1000 Mt per Km of road.
  • 0.12Km of road can be constructed per MW of electricity generated.
  • NO CEMENT - Developed Fly ash based green concrete road without cement with M 40 strength
  • NO WATER CURING - Construction of fly ash based GPC road without water curing.
  • Bulk utilization of Fly Ash
  • Negligible CO2 emission in comparison to high CO2
  • High early compressive strength -Strength is achieved in 7 days in comparison to 28 days for normal Concrete road.
  • Negligible shrinkage – No cracks observed in GPC road
  • Low permeability - Monolithic
  • Good durability in aggressive environment compared to conventional concrete road
  • Low thermal conductivity

Solar PV System

INTRODUCTION:

Ever increasing energy demand, fast depletion of fossil fuels, along with environmental concerns has already made path for emergence of Solar Energy and Solar PV plants are being installed in large scale. However, large Solar PV installations are essentially land intensive which will always be a premium commodity. In the direction of conserving the precious land & water, installing Solar PV system on water bodies like lake, reservoir, canal etc is also an emerging option and becoming attractive particularly when big generating companies like NTPC etc. are having large reservoirs at many stations. Apart from land conservation, Floating PV installations have many other benefits like increase in performance of solar PV panels due to cooling effect, water conservation, reduction in algae growth, quicker installation etc. The main component of floating solar PV system is the floating platform or floaters on which solar modules are installed. Although this concept has become quite prominent worldwide for last few years with installation of large-scale commercial plants, the Indian scenario was not very promising, mainly because there was hardly any availability of floaters produced in India. The cost of imported floaters was also very high. The situation has changed to some extent in last two years with few commercial players entering into this segment.

TECHNOLOGY BRIEF:

I. Design Implemented for 100 kWp pilot system in NTPC Kayamkulam (Weight 230kg/kWp)

In this design, the floating platform consists of main/solar floater, Access floater, connectors, rubber gasket, plastic insert as integral part of main floater and rubber gasket. Illustration of key components e.g. main floater, access floater & connector are as shown below

The solar panels are installed in a landscape orientation with one solar panel fixed on two sets of floaters on either side. The weight of material is approximately 230 tons/MWp. The main challenge faced in this design was production of complex design with blow mould machine available in India.

II. Design  implemented for setting up 1 MWp project at NTPC Kawas (Weight 80kg/kWp)

Based on the experience of previous design it was found that to reduce the cost of floaters, few technical interventions as below could be taken up.

I. Change in orientation of solar panels: so that one solar panel could be supported by one main floater each on either side, instead of two as in the earlier design and thereby reduce the floater by almost half.

II. Change in design of floaters for weight reduction: The complexity of floater is reduced by making the main floater in two-piece, rectangular base and vertical inserts of two heights, as per tilt angle. Presently height of the insert is corresponding to tilt angle of 6 deg.

Hybrid SWH

Solar Wind Hybrid is a concept where both energy sources mutually offset the variations of each other. There are mainly two configurations of Solar Wind Hybrid, DC integration and AC Integration depending on the type of Wind Turbine Generator (WTG) i.e Variable Speed Synchronous Generator (SG) or Doubly Fed Induction Generator (DFIG).

The Hybrid integration is not simply the integration of two systems but requires formulation of design criteria and functionality in terms of control and performance improvement. The objective of the pilot plant installed in Kudgi by NETRA are following

a. Maximize the yield from an identified piece of land and establish the benefits of solar wind hybrid plant over the individual solar or wind plant.

b. Study of effective land utilization by installing the high efficiency solar PV panels in area around wind turbine (WEG) avoiding shadow of the wind turbine.

c. The development of control strategy for active power curtailment (First time in India) when cumulative generation of the solar and wind is above the evacuation capacity

d. Integrating Storage as future project for ramp rate control.

Thermal-Plant

INTRODUCTION:

Solar thermal hybrid applications have the potential to be an important, low-cost option for adding green power to the existing coal based generation fleet, allowing utilities to meet renewable energy targets, reduce plant emissions and lower fuel costs. The hybrid system will inject solar-generated steam / water into the TG cycle of the fossil plants, resulting in a lower reliance on fossil fuels. This approach solves the problem of fluctuations in output associated with solar power and hence maintains the reliability of supply to the grid. Solar energy can be used to either increase power or reduce fuel consumption. Further, Incremental cost increases in steam cycle equipment are smaller than that for standalone solar facility.

Integration of solar thermal plant with 210 MWe coal fired unit of NTPC Dadri (Unit #4) is based on the aforesaid concept. In this hybrid plant, controlled quantity of feed water is tapped from inlet of HP Heater-6, passed through Solar Heat exchanger and again looped back at the exit of HP Heater-6. This shall reduce the extra steam extraction from HP turbine and will help to reduce coal consumption or produce extra units of electrical energy by the plant.
 

TECHNOLOGY BRIEF:

Linear Fresnel mirrors has been installed in solar field which generates pressurized hot water at 80 bar & 280°C. This hot water passes through Solar heat exchanger where it dumps its heat. Solar heater is placed parallel to existing HP Heater #6 (figure 1). A fraction of feed water is made to pass through the solar heater and gets heated up. The control logics ensure that the exit temperature of the feed water at solar heater matches with the feed water exit temperature of HP Heater #6 within close limits of ±2°C. This temperature control is achieved by adjusting the feed water flow through the solar heater. In this process certain amount of steam which was being extracted to heat the entire feed water in HP Heater gets saved and goes on to do additional work in turbine.

Netra-turbine

Flue-Gas-System

INTRODUCTION: 

Convention Air Conditioning System is either (i) Process Steam driven Vapor Absorption System or (ii) Electricity driven Vapor Compression System. Both of the aforesaid air conditioning system utilizes high grade energy.

In every fossil fired power plant, huge quantum of low grade thermal heat is available in form of waste flue gas exiting chimney. However key challenge is harnessing low grade heat from flue gas is to design a heat exchanger which can operate at low LMTC and thereby substantially higher surface area without increasing the differential pressure drop.

Based on the above concept, Flue Gas Waste Heat based for Air Conditioning (FGWH-AC) has been developed. As the primary thermal energy is virtually free of cost, the life cycle cost of air conditioning is very low.

DEMONSTRATION PLANT

NETRA has developed, designed and setup Two such systems:

(i) 100 TR FGWH-AC System at Ramagundam. It is in operation since 2013.
(ii) 400 TR FGWH-AC System at TalcherKaniha. It is in operation since 2017

TECHNOLOGY BRIEF

Flue gas tap off is taken from ID fan outlet and drawn in a slip stream where Gas-to-Water heat exchanger is provided. In the heat exchanger, heat is transferred from flue gas to generate hot water. A booster “flue gas fan” (FG Fan) with Variable Frequency drive (VFD) is also provided in the slip stream duct. The VFD regulates the FG fan speed and controls hot water temperature by modulating the flue gas flow. Vapor Absorption Machine (VAM) of 400 TR capacity is connected to hot water loop. This hot water heat is utilized in VAM to generate chilled water. The chilled water is circulated through AHUs to produce Air-Conditioning in ESP & VFD Control Rooms. The system is designed to operate in fully automatic mode through PLC. A backup steam heat exchanger is provided in case of non-availability of flue gas. 

Flue-Gas-System

  • Utilisation of Solar Energy for Desalination of Sea Water Solar field
  • Compound Parabolic Collector will heat the DM water at around 80 Celcius.
  • Hot DM water is flashed in a Flash Chamber, to generate LP Steam
  • LP Steam is used in a 6-Effect MED to produce Distilled Water
  • Distilled Water will be re-mineralized to produce Drinking Water
  • Auxilliary steam during non solar hours
  • Continuous operation system - No intermittency
  • Minimal chemical consumption

PROJECTS ONGOING:

Motivation:

  • With focus on Green H2, Electrolysis of ultrapure water to produce H2 will become prominent. With scarcity of clean water, providing ultrapure water will be difficult. Low grade and saline water is largely abundant and if it can replace ultra-pure water in electrolyser, considerable saving can be accrued.

Salient Features:

  • Development of efficient and stable catalytic electrode material to withstand sea/hard water.
  • The electrolyser design should be able to deal with complications related to membrane function, reactor degradation and biofouling

Benefits:

  • Cost effective Hydrogen production by electrolysis using sea/hard water.
  • Saving of precious DM Water

Motivation:

  • H2 compression by mechanical compressor is prone to maintenance due to its moving part.
  • To develop a Metal Hydride based static H2 compression system

Salient Features:

  • Metal hydrides stores H2 in solid form and provides high degree of safety, reversibility, high volumetric densities and little energy requirements for practical application.
  • A multi stage Metal Hydride Reactor is being designed for compressing Hydrogen to 250 bar
  • MH alloys are selected in such order, that the desorption condition of first alloy matches with the absorption condition of next alloy.
  • The desorption and absorption conditions are defined by the bed equilibrium pressure with respect to the absorption/desorption temperature, which is directly depends on the required compression of hydrogen
  • Benefits
  • MHHC system does not have any moving components in it, which is the primary advantage.
  • System suitable for stationary application
  • Comparatively low leakage issues to be handled

Benefits

  • MHHC system does not have any moving components in it, which is the primary advantage.
  • System suitable for stationary application
  • Comparatively low leakage issues to be handled

rdf-gasification-based

Motivation:

  • Effective utilization of RDF for Energy and Chemical Generation to make NETRA a “Green Campus”

Salient Features:

  • RDF based gasifier with Steam/CO2 Gasification
  • Syngas clean up system for enabling gas to be used for downstream chemical process
  • Phase-1: Utilization of Syngas for 400 kWe net X 24 hrs power generation
  • Phase-2: Process development for H2 and CO2 Production

Benefits

  • Green Power with environmentally friendly utilization of MSW/RDF

Hydrogen-Grid

Motivation:

  • H2 being considered a clean energy option, cost effective technologies for producing and utilizing green H2 has become an active area of worldwide research and demonstration

Salient Features:

  • NETRA green H2 grid envisages SPV power supply to aElectrolyzer to generate H2 during solar hours, compressing and storing the hydrogen at requisite pressure and using the stored hydrogen to produce 25 kWh Net AC power using a Fuel Cell.

Benefits:

  • Round the clock 25 kWh net AC power from green hydrogen.
  • Establishing process for DC-DC Conversion of SPV and PEM Electrolyzer based on actual Solar Radiation data and SPV characteristics and Electrolyser loading
  • Study Hydrogen grid capability to meet mix active and reactive load
  • Integration and demonstration of other H2 Technologies under development
  • Comparison of SPV based Battery storage and SPV based H2 storage system in actual grid condition
  • Showcasing of novel project to generate data for reference, benchmarking, SOPs, safety and policy formulation

Principle

Motivation:

  • Evaluate efficacy of High Temperature Steam Electrolysis for H2 Generation and its replication and scale up.

Salient Features:

  • High Temperature Steam (750-850 ° C) is utilized for generation of Hydrogen.
  • It is one of the promising technologies for H2 generation.
  • Phase-I: 20 KWeelectrolysershall be installed at NETRA where in Steam Shall be supplied through steam generator. H2 produced shall be fed to planned H2 Grid at NETRA.
  • Phase-II: After successful running for 6-12 months, the same HTSE module shall be transferred to VSTPP where plant steam shall be utilized for H2 generation. H2 produced shall be fed to upcoming Methanol plant at VSTPP.
  •  

Benefits:

  • Reduction in power consumption for H2 generation.
  • Demonstration of a potential H2 generation Technology.
  • It can reduce the cost of H2 generation, fueling growth of HtE (Hydrogen to Energy) &HtP (Hydrogen to Products) ventures.
  • Surplus steam available at thermal power plants can be effectively utilized

EDR-Components

Project :

Development of a pilot 1000LPH(1m3 per hour/24TPD) system and installation at an NTPC Station for study of system efficiency in terms of water recovery and ion removal capacity

Technology:

Electro-Dialysis Reversal (EDR) is an advanced water treatment process based on electrically charged membranes. In EDR, ion exchange membranes are used to separate ionic impurities from water under the influence of DC electric field through flowing water.

Recent developments in membrane technology (leading to cost reduction) and tightening of environmental norms for water disposal and wastewater treatment has renewed interest in EDR technology as an alternative to RO based technologies

Comparison with RO:

EDR Systems have many inherent advantages over RO Systems which are tabulated as below-

SNo.FeatureReverse OsmosisElectrodialysis

1

Power Consumption~5.0kwh/m3~2.0kwh/m3

2

Water Recovery<50% for Single Stage Systems>70% for Single Stage Systems

3

Membrane LifeAround 3 yearsMore than 10 years due to polarity reversal and absence of high pressure.
4Operating ConditionsLow Operating Temperature Range and Chemical WithstandHigh Temperature and Chemical Withstand (upto 50 °C and 1–2 ppm chlorine)

Flue-Gas-CO2

Motivation

  • Capture of CO2 from flue gas of coal based power plant and its conversion to methanol is a priority area for NTPC.
  • The project will strengthen the Government of India vision of ‘Methanol Economy’ in our country.
  • ‘Methanol Economy’ would, in turn, reduce India's dependence on oil imports and simultaneously curb the pollution from electricity sector and thereby helping India meet its Paris Climate Change Agreement obligation to cut carbon emission intensity by 33-35% by 2030.

Salient features

The 10 TPD Flue Gas- CO2 to Methanol Plant (FG-CTM) Plant shall comprise of following 3 units.

  • Carbon Capture Unit: For capturing 20 TPD CO2 from thermal plant flue gas through energy efficient absorption process.
  • Hydrogen Generation Unit: For generating 2 TPD Hydrogen through electrolysis of water, hydrogen being other ingredient for methanol production.
  • Methanol Production Unit : For the conversion of CO2 to Methanol through catalytic hydrogenation process

Benefits:

  • Lower energy demand of Tertiary Amine based energy efficient CO2 capture process as compared to conventional process.
  • Lower expected cost of Methanol produced from full scale FG-CTM plant than the present commercial cost of methanol.
  • This CO2 to Methanol conversion plant shall be a unique plant, globally, where CO2 shall be drawn from waste flue gas of a coal fired power plant and shall be converted to methanol thru a catalytic hydrogenation process. It will also create a potential new business avenues and revenue stream for NTPC.

Existing-STP-Water

Introduction:

Existing Activated Sludge Process has limitation of BOD, COD reduction in STP outlet to meet existing NGT limits of BOD <10 and COD<50 mg/l. Retrofit of AFM based tertiary treatment with existing system enables to meet the NGT norms Tertiary Treated STP effluent can be used as make up CW System. Activated Filter Media (AFM) Technology is selected for NTPC Talcher K and Dadri.

Technology:

Activated Filter Media (AFM) is manufactured by up-cycling post- consumer green glass bottles to produce water filtration media. It is an activated amorphous alumina-silicate with +ve charge organic adsorption (OAD) number greater than 10, the activated hydrophilic surface has cation bridging, hydrogen bonding and entropic interactions with organic molecules

Advantages of AFM:

AFM can be recovered and up cycled for reuse again and again for water filtration, or can be directed into high value uses:

  1. High Removal efficiency from Secondary STP water BOD (<5 ppm) & COD (<50 ppm)
  2. Backwash water requirement reduces by up to 50%.
  3. Increased run phase and reduced back wash could give 15% energy savings.
  4. Reduced chemical consumption, chlorine & flocculants
  5. Expected life expectancy is 5 to 10 yrs.
  6.  

Existing-STP-Water

Project:

Set up of 4MW Ground Mounted Solar Photo Voltaic System with Battery Storage and Load and Source Prioritization with the existing electrical System and Induction based cooking system at NETRA, Greater Noida

Technology:

For making NETRA self-reliant in electricity generation and utilization, set up of 4MW Ground mounted Solar PV plant along with Battery Energy Storage System in phased manner has been planned.

Salient Details:

  • Solar Photo Voltaic Plant: Ground Mounted Solar Photo Voltaic Plant on the land available in NETRA campus and connected to the existing electrical network.
  • Battery Storage System: To cater emergency load during night time and for solar generation smoothening
  • Load and Source Prioritization: Smart controller to maximise the Renewable Generation with Minimum or Nil Grid Intake and prioritize the load and different source (PV, Battery, DG, MSW etc) for electrical system stability.

Grid Independency

SPV based Induction Cooking System in NETRA Canteens: Replacing present PNG based cooking system with flames less Induction based Cooking System in NETRA canteens not only to save expenses on the PNG bills but more fast and healthier cooking environment as compared to conventional PNG based system