How is the power generation cost calculated for the extraction-type steam turbines in fertilizer plants?
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This post was last edited by mimi*aojing on 2010-9-5 at 14:10. The boss asked me to calculate the cost of generating electricity using a 150-ton boiler in the factory. My calculation is as follows: Consumption: 1. Coal required by the 150-ton boiler: 6,890.2 tons； 6890.2*630=4340826.00 yuan 2. Salaries: 81609.36+45609.68=127219.04 yuan 3. Major repairs: 33472.87+556.45=34029.32 4. Maintenance costs: 4344.34+1895.03=6239.37 yuan 5. Desalinated water: 59504*5.6=333222.40 yuan 6. Primary water: 15.5*1.5=23.25 yuan 7. Net auxiliary materials: 9212.63 yuan 8. Low-value consumables: 50.22+35.96=86.18 yuan 9. Consumed materials: 2593.77+233.43=2827.2 yuan 10. Depreciation cost: 310000.00 yuan 11. Manufacturing expenses: 2082.27+544.98=2627.25 Total cost: 7234210.89 yuan Output: I. 1. Total steam produced by the 150-ton boiler: 59310 tons ； Steam output from a 150-ton boiler: 56.93*24*24=32791.68 tons. Electricity consumption of a 150-ton boiler: 814500KWh ； Electricity consumption per ton of steam: 814500/59310 = 13.73 KWh/t of steam. II.1. The total power generation for 24 MW is: 7435200 KWh ； The external power supply for 24MW is: 7435200 – 1476000 = 5959200KWh ； Cost: (7234210.89 – 32791.68*90.25) / 5959200 = 0.717 yuan; (7234210.89 – 32791.68*95.97) / 5959200 = 0.686 yuan; (7234210.89 – 32791.68*95.55) / 5959200 = 0.688 yuan; (7234210.89 – 32791.68*95.58) / 5959200 = 0.688 yuan. Note: The cost of steam at 90.25 yuan per ton is calculated based on an electricity cost of 0.3 yuan per unit; however, it seems that this isn’t quite correct. I’m not sure where the issue lies, so I hope experts can provide some guidance.
Electricity consumption for a 150-ton boiler: 814,500 kWh. How is this shown as output? It should represent the energy consumed, right?
The main issue lies in the calculation of steam costs; based on the total amount of steam produced by the boiler, the cost of steam is far more than 90.25 yuan per ton. When calculating the cost of steam supplied externally, the steam used for deaeration, heating, etc. by the boiler itself must also be included; it cannot all be counted as part of the power generation costs. Calculating the costs of steam and electricity production through cogeneration is complex; generally, the standard coal consumption for electricity generation is calculated first, followed by the coal consumption for steam production, and then the costs for each are determined based on the respective consumption of steam and electricity.