Performance analysis of combined heat and power system equipped with electric boiler and thermal storage device

doi:10.11949/0438-1157.20250270

Abstract

Abstract:

Facing the goal of dual carbon, the flexibility of cogeneration system has become the key, and the realization of thermoelectric decoupling is an urgent task at present. To this end, a combined heat and power model equipped with an electric boiler heat storage device was constructed based on Simulink, and the dynamic characteristics of the system were studied. The NSGA-Ⅱ optimization algorithm and the TOPSIS decision-making model were used to coordinately optimize the economy, environmental protection and power supply capacity. The research shows that the introduction of electric boiler heat storage device significantly improves the performance of cogeneration system. According to the load utilization rate, the differentiated operation strategy of the electric boiler is proposed: the heat storage priority strategy is adopted in the low load utilization rate stage (≤0.2), the direct supply priority strategy is adopted in the high load utilization rate stage (≥0.7), and the mixed mode is adopted in other periods. In addition, the strategy of heat storage tank releasing heat with maximum power during the peak period of electricity price shows the best economic benefits.

Key words: combined heat and power, economics, application study, computer simulation, multi-objective optimization

摘要：

面向“双碳”目标，提升热电联产系统灵活性成为关键，实现热电解耦是当前的紧迫任务。为此，基于Simulink构建配备电锅炉蓄热装置的热电联产模型，研究了系统的动态特性，运用NSGA-Ⅱ寻优算法和TOPSIS决策模型，协同优化经济性、环保性和供电能力。研究表明，引入电锅炉蓄热装置显著改善了热电联产系统性能。根据负荷利用率，提出电锅炉差异化运行策略：低负荷利用率阶段（≤0.2）采用蓄热优先模式，高负荷利用率阶段（≥0.7）采用直接供热模式，其他时段采用混合模式。此外，蓄热罐在电价峰值时段以最大功率放热的策略具有最佳经济效益。

关键词: 热电联产, 经济, 应用研究, 计算机模拟, 多目标优化

CLC Number:

TM 621

Jun LUAN, Lei SONG, Mingming GE, Zhijie SHANG, Xiaoming LI, Gang LI, Xinze LI, Wenjing DU. Performance analysis of combined heat and power system equipped with electric boiler and thermal storage device[J]. CIESC Journal, 2025, 76(11): 6058-6065.

栾俊, 宋磊, 葛明明, 尚志杰, 李小明, 李刚, 李新泽, 杜文静. 配备电锅炉和蓄热装置的热电联产系统性能分析[J]. 化工学报, 2025, 76(11): 6058-6065.

Figures/Tables 12

Fig.1 Schematic diagram of cogeneration system

Table 1 Turbine core design parameters

参数	330 MW机组	350 MW机组
设计功率/MW	330	350
主蒸汽流量/(t/h)	1002.88	983.25
主蒸汽温度/℃	537	566
主蒸汽压力/MPa	16.67	24.2
再热蒸汽温度/℃	537	566
再热蒸汽压力/ MPa	3.2	4.2
供热抽气温度/℃	343	343
供热抽气压力/MPa	0.94	1.0493
排气压力/MPa	0.0054	0.0054

Table 2 Model validation

工况	热/电负荷/ MW	参数	实际值	模拟值	误差/ %
1	1392/815	汽轮机热耗率/(kJ/kWh)	6708.15	6713.58	0.81
	1392/815	煤耗率/(kg/kWh)	0.27161	0.27180	0.69
2	1280/824	汽轮机热耗率/(kJ/kWh)	6359.64	6364.92	0.83
	1280/824	煤耗率/(kg/kWh)	0.25977	0.25995	0.70
3	1522/1032	汽轮机热耗率/(kJ/kWh)	6697.78	6703.34	0.83
	1522/1032	煤耗率/(kg/kWh)	0.26958	0.26977	0.71
4	1401/1061	汽轮机热耗率/(kJ/kWh)	6472.76	6477.03	0.66
	1401/1061	煤耗率/(kg/kWh)	0.26106	0.26122	0.61
5	1273/1116	汽轮机热耗率/(kJ/kWh)	6300.56	6303.53	0.47
	1273/1116	煤耗率/(kg/kWh)	0.25048	0.25063	0.59

Fig.2 Variation of effective power and abandoned power with load factor

Fig.3 Variation of generation income with load factor

Fig.4 Variation of total carbon emissions and coal consumption with load factor

Fig.5 Pareto front

Table 3 Entropy weight method

目标	熵值	差异系数	权重系数/%
$R e$	0.9128	0.0872	39.49
$W e f f e$	0.9199	0.0801	36.26
$E$	0.9465	0.0535	24.25

Table 3 Entropy weight method

目标	熵值	差异系数	权重系数/%
$R e$	0.9128	0.0872	39.49
$W e f f e$	0.9199	0.0801	36.26
$E$	0.9465	0.0535	24.25

Fig.6 Optimum heat supply ratio

Fig.7 Heat release strategy of heat storage tank

Fig.8 Comparison of economic benefits

Table 4 Actual benefits improvement during the heating season

	发电收入/万元	碳排放/万吨	有效电量/GWh
优化策略	20326	270.1	2250.7
常规热电联产厂	18650	281.9	2167.6

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