Question

a) The following figure shows a water dam built for a hydroelectric power project running constantly round the year. During a dry season, it acts as water reservoir of constant height 80 m. Meanwhile rainy season, water flow of 3 m/s is added to the system. (Water density 10x10 kg/m' and volume flow, V = 45x10 m/s respectively and the gravitational acceleration is about 9.8 kg/m for both seasons). Evaluate the followings: Ravet afsec RE Figure 2: Water flow utilization using dam on river Calculate the mechanical energy flow during a dry season. (4 marks) il Realize the mechanical energy flow for the rainy season of constant water flow of 3 m/s for the same dam. (5 marks) ili. Consider that the mechanical energy is utilized to generate electricity and if the efficiency for each step i.e., mechanical to turbine and turbine to electric power generation is 60% efficient; comprehend the electric power generation in this system in dry and rainy season. (5 marks) b) It is appreciated that, the air density or mass flow at different altitude is found different for the same wind velocity. If we assembled two similar shape and size air turbine for renewable energy generation; one in the sea site at nearly sea level and another in the land site of 50 m altitude from the sea level. Comprehend the relative mechanical energy generation relationship between both air turbines. (6 marks)

Answer 1

Sol:- ) dry seos - 10x103 kg /m3 mechanical power (p)}agh e mgh nccoeV APavDer loxo x45xi0xq5x80 TP 352.8GW &) rainy season : mechonicad power(p gn+ ivr 352.8 + 1OXIOX4SX1O% 9 = 354.8 25 Gn pry seasen: 352.8 GW Pmeena = TUrnine power ( Pi)= 0.6x 352.8=21168GW Eleehic power (Pe) - 0 6x21-68 = 127GW Rainy seasesi Pmeeh : 354-825GWI Turbine power CP)= 0.6x 354.825=212.895 Gul Eleetric power ( Pe ) o:6x 212.895= 127.737 Note: Acording to chongo policy we have ro ddo a Scannedone Queshon when multiple aveshys are postel ComScanner