= 2. Use the ratio found in Question 1 above to estimate the water use in L/MWh as well as gal/MWh in a thermal power plant with MPP 0.35 and note whether the water is consumed or withdrawn, for the following two methods: (a) A cooling tower that uses evaporative cooling (see table below for necessary data). (b) A condenser with once through cooling, i.e. using sensible heat (with minimal evaporation), with a maximum temperature rise of 5 C for the water in order not to endanger local aquatic life. For this part, you must first estimate the specific heat of water using the table below (or just use enthalpy values provided in the table). Hint: It is basically an exercise in unit conversion. See table for relevant data on the next page. You can also use the Appendix at the back of our Exercise Book for additional equations and definintions. Table 1: Data adapted from a Steam Table; h is the enthalpy of saturated liquid (= u+pv); hw the latent heat (enthalpy) of evaporation (= h h). Tsat (C) h (kJ/kg) hw (kJ/kg) 15 63.0 2467 20 83.9 2455 25 104.8 2443 30 125.6 2431 [You can write out the final version of your solutions here:] 1. Given the overall efficiency of an electric power plant, pp = We/Qin, (a) derive an expression for the ratio of heat rejected by the power plant (to its surroundings) to the electricity generated (and delivered to the grid), Qout/We, as a function of pp, and then (b) plot Qout/We VS Npp. (Note that We = Qin - Qout.)