Energy Audit of Rajiv Gandhi Thermal Power Plant Hisar Vikas Duhan 1, 1

Research Scholar, Dept. of EE, G.T.C. Bahadurgarh, Haryana, India Email: [email protected]

Abstract- This paper presents Energy Audit of Thermal Power plat with the required demand of electricity is growing fast due to economic growth and increase in population. With the consideration of environmental issues and sustainable development in energy, ideally, renewable energy such as wind, solar, and tidal wave should be only resources to be explored. Since the growth in demand is also a heavy factor in energy equations, then the renewable energy alone is not able to generate enough electricity to fill the gap within a short time of period. Power plants are one of the most suitable choices for environmental enhancement and higher efficiency. However, there has been an issue of whether or not to adopt this technology in the INDIA because it is not clear whether the dynamic response and performance for plants can satisfy the Gird Code requirement. This thesis reports a study of dynamic responses of power plants through mathematical modeling, identification, and simulation. It also presents a new control strategy based on an alternative configuration of generalized predictive control for enhancement of the plant responses. In the process of modeling development, Genetic Algorithms are used for parameter identification and model response optimization. The model has also been verified for certain operation conditions with the different sets of data obtained from 600MW power plant.

Index Terms- Generator, Turbine , Boiler, Condenser, Cooling Tower, Furnace, Transformer, Coal, Oil, Water, Grinder, Chimney, Fans, Bus-bar, Insulator, Relay, Conductor .Circuit Breaker, Super heater, Air pre-heater, Economiser, Ash Handling Plant.

INTRODUCTION To meet the growing demand for energy in industries, one of the aims is to identify the technical support in improving their energy performance through comprehensive energy audits, implementation assistance, technology audits, and capacity building. Energy audits help in identifying energy conservation opportunities in all the energy consuming sectors. While these do not provide the final answer to the problem, but do help to identify the existing potential for energy conservation, and induces the organizations/individuals to concentrate their efforts in this area in a focused manner.[1] In the present scenario of rapidly growing demand of energy in transportation, agriculture, domestic and industrial sectors, the auditing of energy has become essential for over coming the mounting problems of the world wide crisis and environmental degradation. There are two factors contributing to the increase in the energy consumption, one is more than 20% increase in world’s population and another one is worldwide improvement in standard of living of human being. The industrial sector consumes about 50% of total generated energy. Therefore improving energy efficiency is the main focus of Energy Auditing.[2] The energy audit evaluates the efficiency of all process equipment/systems that use energy. The energy auditor starts at the utility meters, locating all energy sources coming into a

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Jitender Singh2 2

Assistant Professor, Dept. of EE, G.T.C Bahadurgarh, Haryana, India Email: [email protected]

facility. The auditor then identifies energy streams for each fuel, quantifies those energy streams into discrete functions, evaluates the efficiency of each of those functions, and identifies energy and cost savings opportunities.[2]

AUDIT OF THERMAL POWER PLANT Energy audit is a technical survey of a plant in which the machine wise, section wise, department wise pattern of energy is balance the total energy input in relation to production mode. It consists of activities that seek to identify conservation opportunities preliminary to the development of an energy savings program.[3] Energy audit methodology is a systematic approach to reduce energy consumption. It converts all forms of energy and energy costs of the system. Aim of the energy audit is to reduce the energy cost per unit of production.[3] The current paper audit of thermal Power Station Hisar, a bunching of two individual units with total installed capacity of 1200 MW is located about 30 KM in the West of Hisar village Khedar on Chandigarh-Hisar National Highway and is surrounded by cultivated green fields. In addition, 989 acres of saline waste land is earmarked for disposal of ash. The plant is equipped with a huge residential colony to ensure availability of staff and officers round the clock. The current chapter includes the study carried out in unit no.2 of Rajiv Gandhi thermal power plant Hisar. This unit is of 600MW installed capacity. In this efficiency of boiler, turbine & generator, condenser & heater are calculated & compared at different loads. After comparing the efficiencies of various sub-units of plant, we find out the losses & also know about the overall efficiency of plant. In this case study the reading of various sub units are taken from the control panel, installed in control room.[4]

Problem Formulation In RGTPP, Hisar 600 MW units is consideration for energy audit and efficiencies of main sub-units as like boiler, turbine and generator, condenser & heater are calculated and compared at different loads which highlights in RGTPP 600 MW units energy efficiency has to be improved to survive in global market.[4]

Brief Information of the PlantInstalled

2 X 600 MW

Capacity

JRPS International Journal for Research Publication & Seminar Vol 05 Issue 02 March -July 2014

989 acres

Available

Sr. no

Land Location

Khedar, Hisar

EPC

M/s Reliance Energy Ltd,

Contractor

Parameter

Indian coal

1

Moisture

5.98

2

Ash

38.63

3

Volatile matter

20.67

4

Fixed carbon

34.69

Rs 3775.428 crore (total estimated

EPC Cost

cost Rs.4512 crore)

Administrat

31.12.2005

ive approval Project

M/s Desein was appointed Project

Consultanc

Consultant and CEA were engaged

y

as Review Consultants

Coal

M/s Mahanadi Coalfields Ltd., Orissa

A boiler is an enclosed vessel that provides a means for combustion heat to be transferred into water until it becomes heated water or steam. The hot water or steam under pressure is then usable for transferring the heat to a process. Water is a useful and cheap medium for transferring heat to a process. When water is boiled into steam its volume increases about 1,600 times, producing a force that is almost as explosive as gunpowder. This causes the boiler to be extremely dangerous equipment that must be treated with utmost care. The process of heating a liquid until it reaches its gaseous state is called evaporation.[5]

Sources Equity

State Govt. is contributing 20% equity

contributio

for the project vide letter dated

n

10.10.2002. Balance 80% Has been arranged through PFC.

Issue

of

Issued to M/s REL vide letter dated 29.01.2007

LOI

Performance of Rajiv Gandhi Thermal Power Plant during last four year OIL YEAR

20102011 20112012 20122013 20132014

GENERAT ION (MU)

P L F (%)

COAL

AUXILIARY CONSUM CONSU CONS. (%) PTION

MPTION

(ml/kwh)

(kg/kwh)

24689

26

9.98

24.065

0.952

55582

54

6.37

2.695

0.756

49929

48

5.93

1.1069

0.736

43819

48

5.83

0.604

0.738

Since the products of flue gases directly contact the stock, type of fuel chosen is of importance. For example, some materials will not tolerate sulphur in the fuel. Also use of solid fuels will generate particulate matter, which will interfere the stock place inside the furnace. Hence, vast majority of the furnaces use liquid fuel, gaseous fuel or electricity as energy input. Melting furnaces for steel, cast iron use electricity in induction and arc furnaces. Non-ferrous melting utilizes oil as fuel.[6] Cooling towers are a very important part of many chemical plants. The primary task of a cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive and dependable means of removing low-grade heat from cooling water. The make-up water source is used to replenish water lost to evaporation. Hot water from heat exchangers is sent to the cooling tower. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling.[6]

Data Analysis In this step, the data, which is collected from Power Plant Unit No.2 & at different output load, is analyzed. Firstly from the data of Thermal Power Plant running at the load of 600MW or full output load given in Table is considered for the analysis purpose. [8] Enthalpy (KJ/Kg) = Cp T Energy (MW) = Flow (Kg/Sec.) x Enthalpy /1000 Temperature is taken in degree Kelvin. The value of enthalpy and energy is given below:- Pressure = 177 Kg/cm2 Temperature = 544 ºC = 817 K Flow=1782 T/Hr. = 1887×1000/3600 = 524.16Kg/sec Enthalpy (Cp T) =4.2 × 817 = 3431.4 KJ/Kg Energy =524.16 × 3431.4/1000 = 1798.62 MW [8]

The typical proximate analysis of various coal Data Analysis of plant at 600 MW Boiler Section

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JRPS International Journal for Research Publication & Seminar Vol 05 Issue 02 March -July 2014

Inlet in Boiler [8] At (40) Coal = 440T/hr = 440 × 1000/3600 = 122.22 Kg. /Sec. Calorific Value = (C.V) of Coal = 3400 K Cal/Kg, (i) Energy = 3400× 122.22 × 4.2/1000 = 1745.30 MW (ii) At (2) Energy = 1217.12MW (iii) At (24) Energy = 1206.90 MW

Outlet from Boiler [8] (iv) At (1) Energy = 1798.62 MW (v) At(3)Energy =1780.33MW (vi) Flue Gases (These are not taken in consideration) Total Inlet = (i) + (ii) + (iii) = 1745.30+1206.90+1217.12 = 4169. 32 MW Total Outlet = (iv) + (v) + (vi) = 1798.62 + 1780.33 + 0 = 3578.95 MW Loss in Boiler = Inlet – Outlet= 4169. 32 – 3578.95 = 590.37 MW Efficiency of Boiler = 3578.95 x 100/4169.32 = 85.84 %

T [7] – T [22] = 218-190 340-190 = 0.186 HPH6 Effectiveness = T [24] – T [23] T [05] – T [23] = 250-218 370-218 = 0.210 HPH7 Effectiveness = T [25] – T [24] T [03] – T [24] = 290-250 540-250 = 0.137

Overall Unit Efficiency [8] Fuel burnt (Coal) = 440T/ Hr = 122.22 Kg/Sec C.V = 3400 K Cal/kg = 3400 × 4.2 = 14280 KW Heat Input = 14280×22.22/1000 = 1745.30 MW Efficiency

Section Turbine & Generator [8] i) HPT Inlet (1) = 1798.62 MW Outlet (2) + (5) = 1217.12 + 149.28 = 1366.40 MW Net Energy at HPT = 1798.62 – 1366.40 = 432.22 MW ii)

= 600 x 100 1745.30

IPT Inlet (3) = 1780.33 MW Outlet (4) + (7) = 1387.22+87.25 = 1474.47 MW Net Energy at IPT = 1780.33 – 1474.47 = 305.86 MW

= 34.37%

iii) LPT Inlet (4) = 1387.22MW Outlet (9) + (11) + (13) = 274.61+260.23 +248.60 = 783.44 MW Net Energy at LPT = 1387.22 – 783.44 = 603.78 MW Net Input at Turbine (HPT, IPT & LPT) = 432.22 + 305.86 + 783.44 = 1521.52 MW Efficiency of Turbo Generator = 600 × 100/ 1521.52 = 39.43 %

Section Condenser [8] Condenser Efficiency = Actual Cooling Water Temp rise Max Possible Temp. Rise Water Outlet Temp.[42]-Water temp. at Inlet [41] * 100 Exhaust Steam Temp. [15] – Water temp. at Inlet [41] = (55 – 45) x100 ( 64 – 45) = 52.63 %

Section Heaters (LP & HP) [8] LPH1 Effectiveness = T [18] – T [17] T [13] – T [17] = 80 – 50 248-50 = 0.151 LPH2 Effectiveness = T [19] – T [18] T [11] – T [18] = 120 – 80 385-80 = 0.131 LPH3 Effectiveness = T [20] – T [19] T [9] – T [19] = 180-120 458-120 = 0.177 HPH5 Effectiveness = T [23] – T [22]

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= Output of Station x 100 Input of Station

=

Modeling This includes the ability to give the required MW response to the load request, keeping continuous optimal operation, and minimizing the fluctuations in the boiler variables which are the main reason for reducing the life of the equipments. However, to achieve those operating objectives, power plant still need more advanced control with higher automation and more flexibility which require learning and adopting one of these advanced technologies in this study.[5] Power plant is a complex process which embeds highly nonlinear features. For physical or mathematical models, a care should be taken in choosing the simulation tool that has the necessary programming language for solving the model equations or optimization problem of parameter identification procedure. The published work in the last two decades for power plant simulations has shown more advanced simulation technologies than the past one. Those tools offer graphical or blocks presentation for the power plant systems which is composed from mathematical operations, integrators, differentiators, transfer functions in s-domain and so on. It therefore has the advantage of easier modification even for the people who are not the main model frame builders. Also, they can be easily understood and adapted with other objects. The graphical simulation also offers the ability to access any variable in the plant without much effort. Some packages that are commonly used for this area of research are[5]

Boiler Model The major boiler model are shown in Fig . The unit of this power plant is 600MW power plant process. Choosing 600MW

JRPS International Journal for Research Publication & Seminar Vol 05 Issue 02 March -July 2014

capacity boiler is mainly because the data for such a power station for model validation could be obtained. The hot water from the feed water heater is heated in the economizer before it is introduced to the superheating stages through the water wall. The super heater consists of three sections which are low temperature super heater, platen super heater, and final stage super heater. The main steam boiler is 16000000 and transport delay is applied whose initial input is zero and time delay 1 and initial buffer size is 1024 applied to pressure sensor is 0.000001 to scope 2 are shown in model. There are two main function are used in this model are step function and ramp function and one error format in the array for expansion value is 0.04 applied for the result output.[5]

are shown by the result. The related data for this model is given byi) The input applied voltage is 570 v and various current source is 50,90,120,160,200,240,280,320,360,400. ii) Voltage source are 64,130,180,222,250,270,280,286,290,294 and % armature currents is 85,110,210,310,410 for the reference resistance is 0.07. fan speed model %Ise (A) 50 90 120 160 200 240 280 320 360 400 %Voc (V) 64 130 180 222 250 270 280 286 290 294 %Sketch the speed - load characteristics of the series fan connected to %570 V main by calculating the speed and load values at armature currents %of 85, 110, 210, 310, 410 A. Ise=[74 110 190 310 420] Vm=570; R=0.07; n=1100; Ea = Vm - (R*Ise) Is=[50 90 120 160 200 240 280 320 360 400]; Vo=[64 130 180 222 250 270 280 286 290 294]; Eo=interp1(Is,Vo,Ise) N=n*Ea./Eo T=(60/(2*pi)).*Ea.*Ise./N plot(T,N);

Fig(1) Boiler model Fan Model The major fan model are shown in given program to find out the curve between speed and load according to fan in and fan out

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JRPS International Journal for Research Publication & Seminar Vol 05 Issue 02 March -July 2014

RESULT AND DISCUSSION The efficiencies of typical 600 MW Plant at load & parameters are compared as follows-

Sr. No.

Description

600MW

1

Boiler Efficiency

85.84%

Turbine & 2

Generator

39.43%

Efficiency 3

4

5

6

7

8

9

10

11

Condenser Efficiency Heater LPH1 Effectiveness Heater LPH2 Effectiveness Heater LPH3 Effectiveness Heater HPH5 Effectiveness Heater HPH6 Effectiveness Heater HPH7 Effectiveness Overall Plant Efficiency Coal Consumption

Fig(2)

Boiler model scope

Fig(3)

Boiler model scope 1

52.63%

0.151

0.131

0.177

0.186

0.210

0.137

34.37%

440 T/Hr

Fig(5) Boiler Model scope 2

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JRPS International Journal for Research Publication & Seminar Vol 05 Issue 02 March -July 2014

CONCLUSION From the analysis part of this work, it is concluded that the overall plant efficiency varies with the variation or small change in the output loads. From the experimental work done in above steps shows that as the output load is lower the efficiency of total unit is low. Output Load of the plant always depends upon the requirements for consumption of energy. As the energy consumption decreases, Plant has to be starting to run at lower load and the overall performance is also lower, because energy cannot be stored. On the other hand if the Plant or Unit can run at Full Output Load or 600 MW load the performance is higher. During the study of plant following main reasons found for energy losses which should be improved and results to increase overall plant efficiency. 1 .Equipment inefficiency. 2. High slop generation/reprocessing rate. 3. High pressure drops in steam/feed/product lines. 4. Heat loses due to poor insulation. 5. Frequent shut-downs/start-up etc. 6. Energy loss from hot surface of heaters. 7. Energy loss from steam lines. 8. Energy loss from electrical systems.[7]

Conclusion for improvement of efficiency There are various methods to improvement in the efficiency of thermal power plant are given below. 1. By using the boiler model and fan model we can improve the efficiency of thermal power plant around 1- 2 %. 2. To reduce the corruption in oil transport system we can improve the efficiency of thermal power plant. 3. Using high Calorific Value of the coal and increasing the oxygen content of the coal we can improve the efficiency of thermal power plant around 1-2 %. 4. Plant should run at higher load also increased in the efficiency of thermal power plant. 5. Reduce air, water, steam, flue gas leakage from the power plant and increased in the efficiency of thermal power plant.

Fig(6) Fan Model REFERENCES [1].Rajan G.G (2001), “Optimizing Energy efficiency in industries by Energy Loss Control-models”, [2] Rask, E Lo, K.L. & Song E, Z. M.(1969), “Tube Failures Occurring in the primary super heaters and re heaters and in the economizers of coal fired boilers”, Energy Conservation in Coal fired boilers , Vol.12, 1969, Page No. 185. [3] “Energy managements” Hand book by C.Turner, Jhon Willey, and sons publication. [4] Dognlin, Chen James, D & Varies B.de (2001), “Review of current combustion, technologies for burning pulverized coal”, Energy conservation in coal fired boilers Vol.48, Page No. 121131. [5] Adams, J., Clark, D.R., Louis, J.R., & Spanbauer, J.P. 1965. Mathematical modeling of once-through boiler dynamics. IEEE Transactions on Power Apparatus and Systems, PAS.Vol.84, issue (2), pp 146-156. [6] “ASHRAE Handbook”, NPC Case Studies in 2013. [7] M. & Lewis, W “Coal ash deposits in coal fired boilers” Energy conservation of coal fired boilers, Vol. 13, , Page No. 170-180. [8] P.K.Nag, R. K Rajput “Power Plant Engineering” Tata McGraw-Hill Publishing Company Limited ” New Delhi. 3 rd Edition.

BIOGRAPHIES Vikas Duhan is a research student. His interested area broadly within Electric Power System. He received his B.Tech from Jind Institute of Engineering & Technology, Jind. Affiliated to Kurukshetra University, Kurukshetra, India and presently pursuing his M.Tech (Power System) from School of PG Engineering A unit of Ganga Technical Campus Approved by AICTE, New Delhi & Affiliated to Maharishi Dayanand University, Rohtak, Haryana, India Jitender Singh is an Assistant Professor in School of PG Engineering A unit of Ganga Technical Campus Approved by AICTE, New Delhi & Affiliated to Maharishi Dayanand University, Rohtak, Haryana, India. He received his B.Tech in 2007 and M.Tech in 2011. His areas of interest are power system Controls and Smart grid.

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JRPS International Journal for Research Publication & Seminar Vol 05 Issue 02 March -July 2014