Syllabus - Heat and Mass Transfer (AT303)

Agriculture Technology

Heat and Mass Transfer (AT303)

III-Semester

UNIT I

Heat transfer mechanism and types

Conduction; Fourier’s law, heat transfer trough various geometries, steady state uni directional flow, insulation. Convection; natural and forced convection. Dimensional analysis of free and forced convection. Useful non dimensional numbers and empirical relationships for free and forced convection. Radiation; Stefan Boltzmann’s law, Krichoff’s law and Plank’s law. Concepts of black body and grey body. Emissivity; shape factor.

UNIT II

Heat exchangers; parallel, counter and cross flow. Logarithmic mean temperature difference. Condensation heat transfer. Introduction to mass transfer, Fick’s law of diffusion, steady state diffusion of gases and liquid through solids, Equimolal diffusion. Convective mass transfer, Analogy between heat, mass and momentum transfer, Application of mass transfer phenomena in food processing.

UNIT III

Principles of refrigeration, second law of thermodynamics applied to refrigeration, carnot cycle, reversed carnot cycle, coefficient of performance, unit of refrigeration. Refrigeration in food industry, types of refrigeration system, mechanical vapour compression, vapour absorption system, components of mechanical refrigeration, refrigerant, desirable properties of ideal refrigerant.

UNIT IV

Centrifugal and steam jet refrigeration systems, thermoelectric refrigeration systems, vortex tube and other refrigeration systems, ultra low temperature refrigeration, cold storages, insulation material, design of cold storages, defrosting. Thermodynamic properties of moist air, perfect gas relationship for approximate calculation, adiabatic saturation process, wet bulb temperature and its measurement, psychometric chart and its use, elementary psychometric process.

UNIT V

Air conditioning – principles‐ Type and functions of air conditioning, physiological principles in air conditioning, air distribution and duct design methods, fundamentals of design of complete air conditioning systems – humidifiers and dehumidifiers – cooling load calculations, types of air conditioners –applications.

Course Objective

The course introduces heat transfer mechanisms and their governing principles along with thermodynamics applied to refrigeration so that the students would understand how the heat and mass transfer from one body to other.

Course Outcome

By the end of the semester, the students will understand the different mechanisms of heat transfer and refrigeration systems.

Practicals

  • Calibrate Copper-Constantannstantan Thermocouple

  • Heat transfer through Metal rod and Composite wall

  • Thermal Conductivity of Insulation Powder

  • Heat transfer in Natural Convection

  • Emissivity Measurement

  • To determine the Stefan Boltzmann Constant for the given material

  • To determine the following for (i) Parallel flow heat exchanger and (ii) Counter flow heat exchanger

    Log mean temperature difference (LMTD) Overall heat transfer co – efficient (Experimental) Overall heat transfer coefficient (Theoretical)

  • Air Conditioning Test Rig

    To demonstrate working of air conditioning system. To demonstrate cooling, heating and humidification processes. To find the coefficient of performance.

Reference Books

  • Arora, C.P. (1981). Refrigeration and Air Conditioning. Tata‐ McGraw Hill

  • Ballaney, P.L. (1980). Refrigeration and Air Conditioning. Khanna Publishers, Delhi‐

  • Arora, S.C and Domkundwar, S. (1984). A Course in Heat & Mass Transfer (3 ed.). Rai & Sons, Delhi.

  • Khurmi R. S. and Guptha J. K. (2004). A text book of Refrigeration & Air conditioning. Eurasia Publishing house (P) Ltd. New Delhi.

  • Treybal, R.E. (1981). Mass transfer Operation. McGraw Hill Book.

  • Holman,J.P. (1989). Heat Transfer S.I. Metric Edition. McGraw Hill Book Company

  • Geankoplis, C.J. (1997). Transport Processes and Unit Operations. Prentice Hall of India, New Delhi.