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Table of Contents

1. Part 1:
   • a. Modern Power Plant Layout
   • b. Steam superheating
   • c. Super-heated steam T-S Plot
2. Task A:
   • 2.1 First Law of thermodynamics
   • 2.2 Relationship between the system constants in Perfect Gas Law
   • Industrial Thermodynamic processes
3. Task B:
   • 3.1 Viscosity in fluid
   • 3.2 Viscosity Measurement Techniques
   • a. Glass Capillary Viscometers
   • b. Cone and plate viscometer
   • c. Ball viscometer
   • Effect of Shear force on Newtonian fluids
4. Task C:
   • 4.1 Fluid system
   • 4.2 Reynold’s number
5. References

PART 1:

Modern Power Plant Layout

Fig 1. The layout of a Modern Thermal power plant

Introduction:

The main function of any power plant is to generate electricity from a different form of input energy in case of the thermal power plant the input is thermal energy, in tidal power plant, the input is tidal energy, in hydroelectric power plants the input is hydro energy, etc. There are many types of power plants exists in this world, but almost 40.4% of world energy needs are satisfied by coal Thermal power plants. A simplified image of a Coal thermal power plant is provided in the above image. The image illustrates all the important parts of the power plant such as Furnace, Boiler, Turbines, Condenser, Generator, Cooling tower, Ash handling unit, Coal handling unit.

Working of modern coal thermal power plant:

As shown in the figure1. Initially, the coal is pulverized into fine grains, then fed into the furnace system where the exothermic chemical reaction between the coal and oxygen results in providing the input heat energy required to convert the water into steam inside the boiler. The steam from the boiler is allowed to superheat, then the super-heated steam is allowed to expand through the turbines, where the kinetic energy of the steam is converted into mechanical energy. A generator is coupled with the turbine, which rotates with the turbine shaft thus the harvested mechanical energy is converted into useful Electrical energy with the help of the Generator. Then the electricity is stored for future use.

The steam that is expanded through the turbine is allowed to pass through a condenser where the expanded steam is converted into liquid form to be utilized for the next cycle. The cooling process is achieved with the help of the cooling towers, where evaporative heat transfer occurs to cool down the hot steam. The Ash collected from the burnt coal is handled properly with the help of the ash handling unit and made harmless to the environment (Askarova, et al, 2015).

b. Steam Superheating:

To enhance the quality of the steam from the boiler the super-heating process is carried out, super-heated steam will have very high kinetic energy and ensures no suspended water molecules are present in the steam. The suspended particles in the steam will create serious problem to the turbine such as corrosion and inefficiency. The super-heated steam ensures safety from corrosion and improves the efficiency of the power generation operation (Alfy, et al, 2016).

c. Super-heated Steam T-S Plot:

The Temperature and Entropy graph for the process can be drawn as:

The power plant works on the principle of the Rankine cycle. AT Vs S diagram shows the Temperature vs Specific entropy plot of a system. The drawn graph is for the super-heated cycle.

Fig 2. T-S Plot for a Super-heated Ranking Cycle

In this system, the major energy transfer occurs with the help of the following parts, the furnace, the boiler, the turbine, and the generator. The conversion of chemical energy into heat energy occurs at the furnace, the conversion of heat energy into the kinetic energy occurs at the boiler, the third stage of conversion of K.E into Mechanical energy occurs at the turbine and then finally the mechanical energy is converted into electrical energy with the help of the Generator.

2. Task A

2.1 First Law of thermodynamics:

The First law of thermodynamics works on the basis of conservation of energy principle which implies that the total internal energy, U present in the system is equal to the total work done on the system and the heat flow occurred. The first law of thermodynamics can be written in mathematical form as:

ΔU = Q – W

ΔU Change in internal energy.
Q – Heat Flow
W- Work was done

2.2 Relationship between the system constants in Perfect Gas Law:

The Perfect gas law states that the total amount of Gas molecules exist in the system is proportional to the pressure and No. of. Gas moles directly and inversely proportional to the system pressure (Nguyen, et al, 2015).

P ∝T
V∝T
PV∝T

Perfect gas law:

PV=n(RT)

here,

P – Pressure
V – Volume
R – Ideal Gas constant
T – Temperature.

Solution to problem:

Given data:

V1: 1 m³

V2: 4 m³

P1: 120 K.pa

P2: 15 K.pa

To Find:

The Polytrophic index, n

The polytrophic index can be found using the relation between the P and V in the polytropic process,

Industrial Thermodynamic processes:

In many industries, various thermodynamic processes are implemented such as Automobile industries, power plant industries, water processing industries, etc. Let us see the thermodynamic process occurs in a power plant industry. The thermodynamic cycle that has been adopted for the Power plant generation using thermal energy is the Rankine cycle. The Rankine cycle consists of 4 processes they are:

• 1-2 isentropic compression
• 2-3 Isochoric process
• 3-4 isentropic expansion
• 4-1 Isobaric process

The energy balance for the whole cycle can be written as:

(Qin-Qout)-(W_Tout-W_{P in}) =0

Thermal efficiency can be written as:

3. Task B

3.1 Viscosity in fluid:

The resistance offered by a liquid to flow is known as the viscosity, the viscous property is measured by the amount of resistance offered by the liquid to oppose the flow. The fluid with high viscosity tends to flow more spontaneously and having low internal molecular friction. Whereas Fluid with low viscosity tends to resist the flow highly.

The viscosity can be simply defined as the ratio of shear stress to the rate of shear.

Where

μ is the dynamic viscosity.

t is the shear stress

du/day is the rate of shear.

3.2 Viscosity Measurement Techniques

a. Glass Capillary Viscometers

Fig 3. Glass Capillary Viscometer

These viscometers are also known as U tube viscometers, Ostwald viscometers, and unbelovedviscometers. This instrument measures viscosity is measured by pouring the sample fluid in the upper bulb via suction, then the fluid is permitted to pass back through the lower bulb. The time taken for the fluid to pass through one point to another (cand d points) is measured and applied in the equation to measure the kinematic viscosity of the fluid (Zhang, et al, 2018).

v=Time (C)

C- Constant

T-Time

b. Cone and plate viscometer

Fig 4. Cone and Plate Viscometer

In this system, a conical geometry is made by the base plate and the cone the sample fluid is allowed inside the space then the rotating torque required is utilized to find the viscosity of the fluid(Zhang, et al, 2018).

c. Ball viscometer

Fig 5. Steel Ball viscometer

The instrument consists of a system tube and steel ball. The sample fluid is poured into the tube, then the steel ball is allowed to pass through the fluid. The viscosity is measured by the observed time taken by the ball to reach the base, also with the help of all the parameters such as environmental pressure, temperature, etc. the measurement is carried out (Nguyen, et al, 2015).

Effect of Shear force on Newtonian fluids:

In the case of Newtonian Fluids, the gradient of velocity or the Shear strain rateis linearly proportional tothe Shear Stress. In the case of a Newtonian fluid, the shear force will impact the fluid and imparts more kinematic energy to the fluid.

4. Task C

4.1 Fluid system:

Hydraulic machinery is one in which the primary source of power for the operation is the fluid. The machines which are operated with the help of Fluid power are known as Fluid powered machinery. If the fluid is in liquid form, then it is known as Hydraulic machinery. If the fluid is compressed air, then the machine is called as pneumatic machinery.

Dynamic analysis is a mathematical approach to analyses a system with the help of basic fundamental elements such as Length, Mass, and Time. There are two methods in dynamic analysis such as the Buckingham’s Pi-theorem, and the Rayleigh’s method. Dimensional analysis can be performed on fluid powered machinery such as Hydraulic press, pneumatic press, Hydraulic lifters, etc.

4.2 Reynold’s number:

Reynolds number is a dimensionless number utilized to measure the Flow condition of the liquid if Reynold’s number is below 2000 then the flow is laminar which means the flow is smooth and lows in a layer. If the Re value is more than 4000 then the fluid is in turbulent motion in which swish and swirl occur.

Dimensionless analysis using Buckingham’s theorem for the Rotating shaft in steam and Gas turbines:

Consider a Power Generation operation, in which the system operates in a Rankine cycle. The steam kinetic energy is used to generate electricity with the help of Turbine, assume that the steam passes through the turbine, the turbine shaft rotates as a result of the conversion of kinetic energy is converted into mechanical energy (Abu-Mahfouz, et al, 2016).

Let:

D be the Shat diameter.

N- Rotation speed of the shaft

P- Power developed.

– Dynamic Viscosity.

E- Fluid Density

WKT,

Pi theorem: π = n-m

Here,

Fundamental variables m are 3 and overall variables are 5.

Calculating Pi value:

π = n-m=2

To find the Power obtained:

Power=0.5 (Density X Diameter) V³

Density E = [M¹ L^-3]

Diamter = [L]

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