Energy Balance Heat Transfer

Energy balance calculation is often done for designing a heat exchanger to determine operating parameters for hot and cold fluids such as inlet outlet temperatures and flow rates.

Energy balance heat transfer. This balance is useful for determining the total heat transfer necessary to accomplish a given temperature change in a system since the internal energy and the enthalpy of any pure substance or mixture can be estimated as a function of temperature given some experimental data using thermodynamics. Change in energy over space. Heat is lost by outgoing long wavelength radiation turbulent transfer to colder air the heat required for the evaporation sublimation or melting glacier glacier heat or energy balance. For bphes a larger area.

In steady heat transfer the temperature and heat flux at any coordinate point do not change with time both temperature and heat transfer can change with spatial locations but not with time steady energy balance first law of thermodynamics means that heat in plus heat generated equals heat out 8. Specific heat and heat capacity. For hot fluid side of a heat exchanger let heat lost by the hot fluid q m h cp h to h ti h. Heat transfer coefficient k.

Conduction the heat is conducted through solid material or a stationary liquid. 1 heat gained by the cold side q m c cp c to c ti c. Energy balance heat thermal energy. Numerical value of heat transferred is positive when it is transferred into the system thereby increasing the energy contained in the system.

Increasing the area of a heat exchanger implies that more energy can be transferred. Forms of heat energy. Rate of change of total energy de dt rate of energy generated deg dt rate of heat transfer in qin rate of heat transfer out qout apply this equation to a solid undergoing conduction heat transfer as shown where. Heat transfer energy balance heat transfer energy balance josh2008 mechanical op 21 oct 10 11 43.

Energy transfer is always from areas of higher to areas of lower energy from warmer to cooler substances. The objectives of this paper determine to formulate a global energy balance in a shell and tube heat exchanger and to study the heat losses firstly focuses to study the heat transfer in countercurrent and parallel flow and to measure the temperature profile in a shell and tube heat exchanger. 1 5 energy balance area a. That is if q is the heat transferred from the surroundings to the system then q 0 means that net heat is transferred to the system so as to increase the energy of the system.