Study on Steam Supply Scheme of Seawater Desalination System Under Low Load Condition of Dual-Purpose Power and Water Plant Units

doi:10.12096/j.2096-4528.pgt.21091

Abstract

Abstract:

In order to ensure the water production capacity of the seawater desalination system under the low load condition of the generator units, and improve the economy of the whole plant, four dual-purpose power and water plant units were taken as examples. The thermodynamic modeling of the four units was carried out by EBSILON software, and the accuracy of the model was verified. The steam sources meeting the conditions of sea fresh water production were analyzed, and three steam extraction schemes meeting the conditions of low load were put forward. Based on the classical theory of thermodynamics, the thermodynamic model was used to demonstrate and analyze the three steam extraction schemes. Moreover, through the comparative analysis of the coal consumption and transformation cost of the three steam extraction schemes, the optimal low load steam supply scheme was obtained. This study has a certain guiding significance for the power plant energy saving and emission reduction and improvement of the economic efficiency of power plant operation.

Key words: dual-purpose power and water plant units, low load operation, thermodynamic analysis, extraction steam optimization

CLC Number:

TK 261

Lixin HUO, Richeng WANG. Study on Steam Supply Scheme of Seawater Desalination System Under Low Load Condition of Dual-Purpose Power and Water Plant Units[J]. Power Generation Technology, 2023, 44(5): 722-730.

Figures/Tables 16

References 19

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参数	一期机组	二期机组
铭牌功率/MW	630	660
主蒸汽流量/(t∙h^-1)	1 874.62	1 822.85
主蒸汽压力/MPa	16.70	24.20
主蒸汽温度/℃	538	566
再热蒸汽压力/MPa	3.33	3.82
再热蒸汽温度/℃	538	566
额定背压/kPa	4.00	4.90
额定给水温度/℃	276.40	275.10
热耗/[kJ∙(kW∙h)^-1]	7 775.00	7 507.10

参数	一期机组	二期机组
铭牌功率/MW	630	660
主蒸汽流量/(t∙h^-1)	1 874.62	1 822.85
主蒸汽压力/MPa	16.70	24.20
主蒸汽温度/℃	538	566
再热蒸汽压力/MPa	3.33	3.82
再热蒸汽温度/℃	538	566
额定背压/kPa	4.00	4.90
额定给水温度/℃	276.40	275.10
热耗/[kJ∙(kW∙h)^-1]	7 775.00	7 507.10

工况	设计值/MW	仿真值/MW	相对误差/%
100%THA	630.0	630.21	0.03
75%THA	472.5	472.33	-0.04
50%THA	315.0	315.15	0.05
40%THA	252.0	252.65	0.26

工况	设计值/MW	仿真值/MW	相对误差/%
100%THA	630.0	630.21	0.03
75%THA	472.5	472.33	-0.04
50%THA	315.0	315.15	0.05
40%THA	252.0	252.65	0.26

工况	设计值/ [kJ⋅(kW⋅h)^-1]	仿真值/ [kJ⋅(kW⋅h)^-1]	相对误差/%
100%THA	7 775.00	7 776.55	0.02
75%THA	7 858.20	7 860.08	0.02
50%THA	8 226.30	8 228.87	0.03
40%THA	8 519.70	8 510.33	-0.11