Latent heat storage systems

Component 2 Latent heat storage system Removed exergy by the LHS system during charging is... 

Aceves-Saborio, S., Nakamura, H., and Reistad, G.M., 1994, Optimum efficiencies and phase change temperatures in latent heat storage systems, ASME J. Energy Res. Technol. 116 ... 

Bascetincelik, A., Ozturk, H.H., Paksoy, H.O., and Demirel, Y., 1999, Energetic and exer-getic efficiency of latent heat storage system for greenhouse heating, Renewable Energy 16 691-694. 

Ramayya, A.V., and Ramesh, K.N., 1998, Exergy analysis of latent heat storage system with sensible heating and subcooling of PCM, Int. J. Energy Res. 22 411—426. 

A charging fluid heats the phase changing material, which may initially be at a subcooled temperature Tsc, and may eventually reach a temperature 7 sh after sensible heating. Therefore, the latent heat storage system undergoes a temperature difference of 7 sh 7 sc, as shown in Figure 5.19. Heat available for storage would be... 

Figure 5.18. Units of the latent heat storage system.

Unit 2 Latent heat storage system - Figure 5.19 shows an approximate temperature profile within the storage unit. The removed exergy by the latent heat storage system during charging is... 

The thermoeconomics of the latent heat storage system involves fixed capital investment, operational and maintenance cost, and exergy costs. The total fixed capital investment consists of (i) direct expenses, which are equipment cost, materials, and labor, (ii) indirect project expenses, which are freight, insurance, taxes, construction, and overhead, (iii) contingency and contractor fees, and (iv) auxiliary facilities, such as site development and auxiliary buildings. Table 5.7a shows the data used in the thermoeconomic analysis. 

Discounted cash flow diagram can determine the profitability criteria in terms of the payback period, net present value, and rate of return from. In the discounted cash flow diagram each of the annual cash flow is discounted to time zero for the latent heat storage system. The payback period is the time required, after construction, to recover the fixed capital investment. The net present value shows the cumulative discounted cash value at the end of useful life. Positive values of net present value and a shorter payback period are preferred. The rate of return is the interest rate at which all the cash flows must be discounted to obtain zero net present value. If rate of return is greater than the internal discount rate, then the latent heat storage system is considered feasible. 

Use the following economic data and prepare a discounted cash flow diagram. Asses the feasibility of the investment on the latent heat storage system ... 

FIGURE 5.14 Cash flow diagram based on the economical data in Table 5.5a and cumulative cash flows in Table 5.5b for the latent heat storage system. 

Koca A, Oztop HE, Koyun T, Varol Y. Energy and exergy analysis of a latent heat storage system with phase change material for a solar collector. Renew Energy 2008 33 558-67. 

Jesumathy SP, Mudayakumar M, Suresh S. Heat transfer characteristics in latent heat storage system using paraffin wax. J Mech Sci Technol 2012 26(3) 959-65. 

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