Question

Load Duration Curve A gas-fired boiler system is being design for a new building. The system will consist of 3 identical boilers, each with rated output = 200 kW. The anticipated LDC is shown below. 600 500 Heating Load 400 [kW] 300 200 100 0 The planned operating sequence is as follows: Boiler-1 fires first to meet whatever load it can, up to its capacity. When Boiler-1 reaches its capacity, Boiler-2 fires second and operates to meet whatever load it can (above that met by Boiler-1), up to its capacity. Boiler-3 is then added in sequence in a similar way to that of Boiler-2. Based on the planned operating sequence, estimate the following quantities: 0 1000 3000 2000 Hour Number i) annual maximum heating load [kW] ii) annual minimum heating load [kW] iii) number of hours per year during which Boiler-3 will operate iv) total annual heating load (kWh) during those hours when Boiler-3 operates v) annual fuel consumption [m] of Boiler-3 if it operates with an average n = 70%. Assume the heat content of natural gas is 10.33 kWh/m.

Answer 1

Rated power output we have Soon Por solving the question obseque graph very carefully Given Dala, Number of boilers = N-3 P = 200 KW / boiles. firing sequence of boiles Boiler t Boileg 2 → Boiler 3 1.). Annual maximum load heating dimeve 600 kW load 27 Annual miniam imum heating Qmin - 0 kW Any 32 As Boiles + meet 200 kW Boiler 2 meet next 200 kw so, Boiler 3 will start after 400 kw 400 kw will hours give of the duration above operation of boiler os,

So, boiler 3 operates operates for time, Tz=250 hrs in Potal onnual of lood of load o Boiles & load of + heating lood during Boiles 3 Boiler 2 boiles 3 @ope stenen (kn) s! 200x250 +2004250 + 5x250 x 200 Tolo) : 125000 KW.hy heating load, A

(CV) 10:33 KWh/m² Heat content of natural gas boiles 3 Efficiency of 2) 0.7 Hearing load of boules of booles - (Qweed) (Qwed), - SX 250 X200 (dovod), - 25.000 kWh Load)3 1) Heat seopplied natural by gas 0. 25000 max 10.33 kwh/m3

3 3 minio 345773 m Annual foul Consumphon fre

Please forgive me for any calculation mistake and do comment for any short of queries.