It will raise their feedwater temperature and then improve their operating economy to add No.0 HPH (high-pressure heater) in thermal power units. A steam-water distribution model for a thermal system coupled with No.0 HPH was established based on the mass and energy conservation laws. And a variable-condition calculation method for its heat economics was also proposed. Furthermore, a derivative characterization approach was developed to represent the heat economics impact of No.0 HPH extracted steam flowrate, which realize the quantitative evaluation before and after coupling with No.0 HPH. Taking a 600 MW unit for example to carry out calculations and analysis, it indicates that the index calculation error of the method proposed in this paper is less than 0.15%, which has high precision and can be used for thermal economic evaluation of large thermal power units coupled with No. 0 HPH. Furthermore, after coupling No.0 HPH, the feedwater temperature can be lifted by 19.1~32.3 ℃, the cycle heat efficiency raised by 0.18%~0.2%, and the heat consumption rate decreased by 29.3~34.6 kJ/(kW·h). Moreover, the sacrificial internal work will be even smaller, and the heat consumption decrease be even larger if the turbine load was smaller.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |