mechanical engineering thermodynamics pdf

Two novel configurations are proposed to replace the conventional Rankine cycle based steam power plants (SPP) with natural draft wet cooling towers (NDWCT) as cooling units. This positions them in premium places in the energy scenario, as heat is frequently available at temperatures not high enough for an efficient heat to work conversion. Since absorption cycles consume heat instead of work, many different energy sources can be used as input, going from convectional gas combustion to waste heat and renewable sources. It produces cold when evaporating in the evaporator (e) and heat when condensing at higher pressure p in the condenser (c) and consequently at a higher temperature as the refrigerant usually is a pure substance. In both kinds of cycles, the phase change of a volatile substance, called refrigerant, is used internally as a working fluid. applications have reached a commercial stage and a lot of innovative systems are being investigated, absorption machines are not so common now, owing to a higher cost and bulk than the work-driven technologies based on the inverse Rankine cycle, which uses a mechanical compressor (k), Figure 8.1, usually consuming electricity. An absorption machine is able to transfer heat from a cold source to a hot sink consuming 112heat from an external third source, working as a heat-driven heat pump. Since the French scientist Ferdinand Carré built the first absorption machine in 1858, it has been intensively developed, and it now offers many possibilities of use. Unit 5 elaborately discusses various gas mixtures and psychrometry topics such as mole and mass fraction, Dalton’s and Amagat’s laws, properties of gas mixture such as molar mass, gas constant, density, change in internal energy, enthalpy, entropy and Gibbs function, psychrometric properties and its calculations for air vapour mixtures by using chart and expressions, psychrometric process such as adiabatic saturation, sensible heating and cooling, humidification, dehumidification, evaporative cooling and adiabatic mixing.Ībsorption is a technology many years old.This unit also deals with Maxwell relations, Tds Equations, difference and ratio of heat capacities, energy equation, Joule-Thomson coefficient, Clausius Clapeyron equation, phase change processes.

Unit 4 dealt with ideal and real gasses under which various topics such as properties of ideal gas, equations of state for ideal and real gases-reduced properties, compressibility factor and generalized compressibility chart are discussed.Unit 3 deals with properties of pure substances, phase rule, p-V, p-T, T-V, T-s, h-s diagrams, PVT surfaces, determination of dryness fraction, application of I and II law for pure substances, ideal and actual Rankine cycles, cycle improvement methods such as reheat and regenerative cycles, economiser, preheater, binary and combined cycles.Unit 2 has wide coverage of second law of thermodynamics in which various topics such as heat reservoir, source and sink, heat engine, refrigerator, heat pump, statements of second law and its corollaries, Carnot and reversed Carnot cycles, Clausius inequality, concept of entropy, T-S diagram, Tds equations, entropy change for pure substance, ideal gases, and different processes, principle of increase in entropy, applications of II law, high and low grade energy, available and non-available energy of a source and finite body, energy and irreversibility, expressions for the energy of a closed system and open systems, energy balance and entropy generation, irreversibility, I and II law efficiency are discussed.This unit also deals with first law of thermodynamics applied to closed & open systems and steady flow process. Unit 1 deals with basic concepts of thermodynamics such as concept of continuum, microscopic and macroscopic approaches, path and point functions, intensive and extensive properties, total and specific quantities, system and their types, thermodynamic equilibrium state, path and process, quasi-static, reversible and irreversible processes, heat and work transfer, displacement work and other modes of work, P-V diagram, Zeroth law of thermodynamics, concept of temperature and thermal equilibrium, relationship between temperature scales, and new temperature scales.

Mechanical engineering thermodynamics pdf