Heat Exchanger Heat Transfer Coefficient U Factor Nuclear Power

Heat Exchanger Heat Transfer Coefficient U Factor Nuclear Power Consider a parallel flow heat exchanger used to cool oil from 70°c to 40°c using water available at 30°c. the outlet temperature of the water is 36°c, and the rate of flow of oil is 1 kg s. the specific heat of the oil is 2.2 kj kg k. the overall heat transfer coefficient u = 200 w m2 k. calculate the logarithmic mean temperature difference. Heat transfer in a heat exchanger usually involves convection in each fluid and thermal conduction through the wall separating the two fluids. it is often convenient to work with an overall heat transfer coefficient, known as a u factor, in analyzing heat exchangers. the u factor is defined by an expression analogous to newton’s law of cooling.

Heat Exchanger Heat Transfer Coefficient U Factor Nuclear Power Heat exchanger design selections must be driven by functions and requirements. optimum designs will vary significantly with application and requirements. compact hxs are essential for some applications, e.g., htgr gt recuperators, htgr ph ihx. in other applications, incentives are not so clear, e.g. sfr. and ahtr ihx. Analysis of heat exchangers. heat exchangers are commonly used in industry, and the proper design of a heat exchanger depends on many variables. it is often convenient to work with an overall heat transfer coefficient, known as a u factor, in analyzing heat exchangers. the u factor is defined by an expression analogous to newton’s law of cooling. The rate of heat transfer for each area would then be expressed as dq = ux(thl tcl) da. (8) in eq. (8) ux may be considered as being analogous to a sum of electrical resistances and is given by heat exchangers in nuclear power plants 61 u x = [ . »> da lhhmdah dah da (rq rw) da kwdaw fseda dah da l" hcxdac] 1 ,g. Figure 1.1: conduction heat transfer. the second heat transfer process is convection, or heat transfer due to a flowing fluid. the fluid can be a gas or a liquid; both have applications in aerospace technology. in convection heat transfer, the heat is moved through bulk transfer of a non uniform temperature fluid.