Thermal power plant or Steam power plant

A generating station which converts heat energy of coal combustion in to electrical energy is known as Thermal power plant or Steam power plant. Some of its advantages and disadvantages are given below.

Advantages

The fuel used is quite cheap.
Less initial cost as compared to other generating plants.
It can beinstalled at any place iirespective of the existence of coal. The coal can be transported to the site of the plant by rail or road.
It require less space as compared to Hydro power plants.
Cost of generation is less than that of diesel power plants.
Disadvantages

It pollutes the atmosphere due to production of large amount of smoke and fumes.
It is costlier in running cost as compared to Hydro electric plants.

OFFICE SAFETY

Staff who work exclusively in offices should be aware that they have the RIGHT TO KNOW any laboratory hazards in the surrounding area and they should feel free to discuss any questions or concerns with any member of the Department Safety Committee.
It is the responsibility of each employee to perform his or her job in a safe manner. Safety is as important in the office as it is in the laboratory.

Offices should be inspected by the occupants for earthquake hazards. Tall bookshelves and cabinets (including lateral file cabinets) must be anchored to the wall or made secure by other approved means (contact John Souza, 2-3314). There should be no overhead storage that could create a falling hazard.
Extension cords are not to be used. Approved multi-plug strips may be used as long as they have an internal breaker and are not run in series with other cords (daisy-chained). All cords should be inspected for wear, frayed cords are to be replaced.
Use of space heaters has been specifically prohibited by the State Fire Marshal. Problems with room heat should be reported to Physical Plant, 2-1032.
Furniture arrangement in offices should permit a quick exit in an emergency. Quantities of paper or other combustibles must be kept at a minimum.
EH&S (2-3073) has many brochures available regarding display terminals (VDT) and other office machinery.

Thermodynamics process of a perfect gas

Adiabatic process

Polytropic process

Constant Volume Process

Throttling Process

Free Expansion ( Unresisted Expansion ) Process

               The free expansion process is an irreversible non-flow process. A free expansion process occurs when a fluid is allowed to expand suddenly into a vacuum chamber through an orifice of large dimensions.

               Consider two chamber A and B separated by a partition. Since there is no expansion of the boundary of the system, because it is rigid, therefore no work is done. Thus, for a free expansion,
                                    Q1-2 = 0; W1-2 = 0 and dU = 0
                The following points may be noted regarding the free expansion of a gas:
1. Since the system is perfectly insulated so that no heat transfer takes place therefore the expansion of gas may be called as an adiabatic expansion.
2. Since the free expansion of the gas from the equilibrium state 1 to the equilibrium state 2 takes place therefore the intermediate state will not be in equilibrium states.
etc...

Rate of Heat Transfer

                    Heat transfer during a polytropic process
                                        Q1-2 = (segma) - n / (segma) - 1 * W1-2
 where W1-2 is the work done during polytropic process.
                     If dQ is the small quantity of heat transfer during small change of pressure and volume, then
                                                 dQ = (segma) - n / (segma) - 1 * pdv
Rate of heat transfer per unit volume,
                                                dQ / dv = (segma) - n / (segma) - 1 * p

and rate of heat transfer per second,

                                     dQ / dt = dQ / dv * dv / dt = (segma) - n / (segma) -1 * p * dv / dt

where dv / dt is the swept volume of the piston per second.

Constant Tempreture Process (Isothermal Process)

             A process, in which the tempreture of the working substance remains constant during its expansion or compression, is called constant tempreture process or isothermal process. This will happen when the working substance remains in a perfect thermal contact with the surroundings, so th

at the heat "sucked in' or 'squeezed out' is compensated exactly for the work done by the gas or on the gas respectively. It is thus obvious that in an isothermal process:
    1. there is no change in tempreture.
    2. there is no change in internal energy, and
    3. there is no change in enthalpy.
          Now consider m kg of a certain gas being heated at constant tempreture from an intial state 1 to final state 2.
    Let                 p1v1 and T1 = Pressure, volume and tempreture at the intial state 1, and

                          p2v2 and T2 = Pressure, volume and tempreture at the final state 2.

Hyperbolic Process

           A process, in which the gas is heated or expanded in such a way that the product of its pressure and volume (i.e *v ) remains constant, is called a hyperbolic process.

          It may be noted that the hyperbolic process is governed by Boyle,s law i.e p v = constant. If we plot a graph for pressure and volume, during the process as shown in fig we shall get a rectangular hyperbola. Hence, this process is terned as hyperbolic process. It is merely a theoretical case, and has a little importance from the subject point of view. Its practical application is isothermal process, which is discussed below.

General Laws for Expansion and Compression

     The general law of expansion or compression of a perfect gas is pVn = Constant. It gives the relationship between pressure and volume of a given quantity of gas. The value of n depends upon the nature of gas., and condition under which the changes take place. The value of n may be between zero and infinity. But the following values of n are important from the subject point of view.

1. when n = 0. This means pV0 = constant, i.e.p = constant. In other words, for the expansion or constant of a perfect gas at constant pressure, n = 0.

2. when n = 1 ; then pv = constant, i.e the expansion or compression is isothermal or hyperbolic.
3. when n lies between 1 and n, the expension or compression is polytropic, i.e. pVn = Constant.
4. when n = & the expension or compression is adiabatic

5. when n = infinity the expansion or compression is at constant volume, i.e. v - Constant.

Importance of Critical Steel Ratio in Calculating Thermal Reinforcement

The fulfillment of critical steel ratio means that in construction joints or planes of weakness of concrete structure, steel reinforcement will not yield and concrete fails in tension first. This is important in ensuring formation of more cracks by failure of concrete in tension, otherwise failure in steel reinforcement would produce a few wide cracks which is undesirable. 

   What is the difference in arranging pumps in series and in parallel… solved example extracted from the topic Pumping Station of steel structures based on civil engineering… identical pumps with similar functions, if the pumps arranged in series, the total head is increased without a change to maximum discharge...

Functions of Cap Block, Drive Cap and Pile Cushion
   What are the functions of cap block, drive cap and pile cushion in driven piles… Solved example based on the topic piles and foundation Marine Piles of Reinforced Concrete Design of civil engineering subject… Cap block is installed between the hammer end and the drive cap to control the hammer blow in order to protect both the hammer and the pile from damage.

Relation of Bearing Pressure
   What is the relation of bearing pressure on soil nail head to the ratio La/Lb, where La is the length of soil nail before the potential slip circle…sample problem based on the topic Soils & Rocks from the Soil Mechanics of Civil Engineering subject… unstable soil mass before the potential circular slip is resisted by two components: soil nail head bearing pressure and friction of soil nail in the unstable soil mass...

Acetylene Gas Cylinders used for Gas Welding
   Why should acetylene gas cylinders used for gas welding be erected in upright position… Solved Example based on the topic Steel Structural Analysis of structure from the subject Civil Engineering… Acetylene gas is commonly used for gas welding because of its simplicity of production and transportation and its ability to achieve high temperature in combustion...

Major Problems in Using Pumping
   What are the major problems in using pumping for concreting works… solved example extracted from the topic Composite Steel-Concrete Construction of steel structures based on civil engineering… The main problems associated with pumping are the effect of segregation and bleeding…

SAFETY PRECAUTIONS AND OPERATING INSTRUCTIONS

When engineering personnel work outside of the engineering department, the responsibility for training and enforcing safety precautions rests with the head of the  department  controlling  the  operation.  For  example, weapons and ammunition handling requires special instructions by the weapons officer. The   engineer   officer   has   the   following responsibility  for  safety  in  the  engineering  department: l l l Be  sure  safety  precautions  are  posted  in  a conspicuous  and  accessible  places. Be sure all persons in the department and others who  may  be  concerned  with  engineering  matters observe safety precautions. Drill personnel in the safety procedures that apply to their work. Each   division   officer   has   the   following responsibilities for safety in his division: l l l Instruct  subordinates  in  all  safety  precautions that  apply. Require  subordinates  to  observe  all  safety precautions that apply. Post   safety   precautions   and   warnings   in conspicuous  places.  This  includes  posting warnings on dangerous equipment and in areas of the ship where there are particular hazards. Each  member  of  the  engineering  department  has the  following  responsibilities: l l l l l Report  unsafe  conditions  and  correct  the conditions  where  possible. Warn  others  of  unsafe  conditions. Use  approved  protective  clothing  and  equipment where it is called for. Report injury or ill health to supervisors. Use caution in emergency conditions or other dangerous  situations. WARMING-UP SCHEDULES Warming-up schedules for propulsion machinery and boilers are chronological checklists of the key steps used to light boiler fires and warm up the ship’s main engineering plant.