INSTRUMENTATION IN POWER PLANT

This blog covers the following areas pertaining to instrumentation and control. • Pressure • Flow • Level • Temperature • Neutron Flux • Control Pressure • explain the basic working principle of pressure measuring devices, bourdon tube, bellows, diaphragm,      capsule, strain gauge, capacitance capsule; • explain the basic operation of a differential pressure transmitter; • explain the effects of operating environment (pressure, temperature, humidity) on pressure detectors; • state the effect of the following failures or abnormalities:  over-pressuring a differential pressure cell or  bourdon tube;  diaphragm failure in a differential pressure cell;  blocked or leaking sensing lines; and  loss of  loop electrical power. Flow • explain how devices generate a differential pressure signal: orifice,  venturi, flow nozzle, elbow, pitot tube, annubar; • explain how each of the following will affect the ind...

Introduction While it is theoretically possible to operate a boiler with manual control the operator must maintain a tedious, constant which for disturbances and variations of parameters. Time is needed for the boiler to respond to a correction and this lead to over correction with further upset to the boiler. An automatic controller once properly tuned will make the proper adjustment quickly to minimize upsets and will control the system more accurately  and reliably. Instrumentation systems are provided for the boiler to achieve the following: 1. To measure the actual values of different parameters for which the boiler is designed. 2. Safe working range of the different parameters is maintained. 3. To monitor one or more variables at a time and provide input for automatic control. 4. In case of operator failure to take remedial action for an upset condition, it protects the boiler by alarms and trippings. 5. To provide data on operating conditions before failure of...

For various transmitters they come in different ranges of pressure so conversion table is required.

TURBINE   Steam Turbine A steam turbine is a prime mover, which continuously converts the energy of high pressure, high temp steam supplied by a steam generator into shaft work with the low temp steam exhausted to a condenser. The energy conversion takes place in two steps:– The high pressure & temp steam first expands in nozzle & comes out at high velocity. The high velocity jets of the steam coming out of the nozzle, impinges on blades mounted on a wheel, get deflected by an angle & suffer a loss of momentum which is absorbed by rotating wheel in producing torque.  1.    Speed                                                        i.  ...

CLASSIFICATION OF POWER PLANT CYCLE Power plants cycle generally divided in to the following groups, (1) Vapour Power Cycle (Carnot cycle, Rankine cycle, Regenerative cycle, Reheat cycle, Binary vapour cycle) (2) Gas Power Cycles (Otto cycle, Diesel cycle, Dual combustion cycle, Gas turbine cycle.) CARNOT CYCLE This cycle is of great value to heat power theory although it has not been possible to construct a practical plant on this cycle. It has high thermodynamics efficiency. It is a standard of comparison for all other cycles. The thermal efficiency (η) of Carnot cycle is as follows: η= (T1– T 2)/T 1 where, T1 = Temperature of heat source T2 = Temperature of receiver RANKINE CYCLE Steam engine and steam turbines in which steam is used as working medium follow Rankine cycle. This cycle can be carried out in four pieces of equipment joint by pipes for conveying working medium as shown in Fig. 1.1. The cycle is represented on Pressure Volume P-V and S-T diagra...