Comparative Evaluation of Thermoelectric Decoupling Potential and Economy of Multi-Type Small Capacity Thermal Power Units

doi:10.12096/j.2096-4528.pgt.22144

Abstract

Abstract:

Objectives New energy power generation faces significant fluctuations and instability in output power and generation load, posing certain challenges to the stable operation of the power system. After thermoelectric decoupling, small-capacity thermal power units participate in the overall operation of the power system, which can improve power grid dispatch efficiency and system security.To this end, various thermoelectric decoupling technologies were adopted to transform three small-capacity thermal power units. Methods Various technical routes were compared and studied. by using EBSILON Professional software for simulation experiments, the potential of various thermoelectric decoupling schemes in peak-load regulation was evaluated and analyzed comparatively, and the economics of the retrofitted units were analyzed. Results The water-cooled back-pressure unit has a larger potential space for thermoelectric decoupling, with obvious advantages over other units, and the maximum daily profit under heating for the heat pump retrofit unit increased by 2.171 8 million yuan. With the change of extraction steam heat load, the thermoelectric decoupling potential of the water-cooled condensing unit shows an overall trend of gentle variation and is the easiest to control, with the maximum daily profit under heating for the heat pump retrofit unit increasing by 2.022 5 million yuan. The maximum daily profit under heating for the air-cooled condensing unit with heat pump retrofit increased by 261 300 yuan. Conclusions The thermal power units that have undergone thermoelectric decoupling upgrades can significantly enhance their peak shaving effect. The heat pump retrofit can effectively increase daily profits, thereby improving the stability and efficiency of the entire power generation system.

Key words: thermal power units, cogeneration, thermo-electric decoupling, extraction heating, deep peak shaving, virtual power plant, economical analysis

CLC Number:

TK 09

Qiwei ZHENG, Xinyue ZHAO, Di LU, Heng CHEN, Peiyuan PAN, Tong LIU. Comparative Evaluation of Thermoelectric Decoupling Potential and Economy of Multi-Type Small Capacity Thermal Power Units[J]. Power Generation Technology, 2024, 45(5): 929-940.

Figures/Tables 14

References 24

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参数	1#机组	2#机组	3#机组
主蒸汽温度/℃	535	535	535
主蒸汽压力/MPa	8.83	9.50	8.83
主蒸汽流量/(kg⋅s^-1)	39.31	28.39	28.22
额定背压/MPa	0.300	0.022	0.018
给水温度/℃	216.34	223.90	272.20
额定功率/kW	25 071.6	25 000.00	25 004.02
热耗/[kJ/(kW⋅h)]	3 774.5	10 238.1	10 450.3

参数	1#机组	2#机组	3#机组
主蒸汽温度/℃	535	535	535
主蒸汽压力/MPa	8.83	9.50	8.83
主蒸汽流量/(kg⋅s^-1)	39.31	28.39	28.22
额定背压/MPa	0.300	0.022	0.018
给水温度/℃	216.34	223.90	272.20
额定功率/kW	25 071.6	25 000.00	25 004.02
热耗/[kJ/(kW⋅h)]	3 774.5	10 238.1	10 450.3

参数	#1机组			#2机组			#3机组
参数	设计值	计算值	相对误差/%	设计值	计算值	相对误差/%	设计值	计算值	相对误差/%
主蒸汽温度/℃	535.00	535.00	0.00	535.00	535.00	0.00	535.00	535.00	0.00
主蒸汽压力/MPa	8.83	8.83	0.00	9.50	9.50	0.00	8.83	8.83	0.00
主蒸汽流量/(kg⋅s^-1)	141.50	141.50	0.00	102.22	102.22	0.00	101.60	101.60	0.00
额定背压/kPa	300.00	300.00	0.00	22.00	22.00	0.00	18.00	18.00	0.00
给水温度/℃	216.34	216.67	0.15	223.90	218.95	-2.21	210.00	216.67	3.18
额定功率/kW	25 071.60	25 324.40	1.01	25 000.00	25 425.00	1.70	25 004.02	25 324.40	1.28
热耗/[kJ⋅(kW⋅h)^-1]	3 774.50	3 644.20	-3.45	10 238.10	10 164.82	-0.72	10 450.27	10 056.66	-3.77

参数	#1机组			#2机组			#3机组
参数	设计值	计算值	相对误差/%	设计值	计算值	相对误差/%	设计值	计算值	相对误差/%
主蒸汽温度/℃	535.00	535.00	0.00	535.00	535.00	0.00	535.00	535.00	0.00
主蒸汽压力/MPa	8.83	8.83	0.00	9.50	9.50	0.00	8.83	8.83	0.00
主蒸汽流量/(kg⋅s^-1)	141.50	141.50	0.00	102.22	102.22	0.00	101.60	101.60	0.00
额定背压/kPa	300.00	300.00	0.00	22.00	22.00	0.00	18.00	18.00	0.00
给水温度/℃	216.34	216.67	0.15	223.90	218.95	-2.21	210.00	216.67	3.18
额定功率/kW	25 071.60	25 324.40	1.01	25 000.00	25 425.00	1.70	25 004.02	25 324.40	1.28
热耗/[kJ⋅(kW⋅h)^-1]	3 774.50	3 644.20	-3.45	10 238.10	10 164.82	-0.72	10 450.27	10 056.66	-3.77

方案	煤耗率/[kg⋅(kW⋅h^-1)]			日净利润/万元
方案	5 MW供热	50%供热	原最大供热	5 MW供热	50%供热	原最大供热
#1案例	532.17	603.11	724.91	472.28	410.54	259.76
#1低零	558.88	631.07	754.14	410.74	346.13	165.19
#1高背	653.90	711.27	798.78	-120.19	-60.98	-20.17
#1热泵	496.69	563.01	671.40	648.71	597.75	476.94
#2案例	384.75	419.42	480.57	784.45	679.03	514.56
#2低零	439.04	469.25	523.76	456.57	403.94	302.06
#2高背	389.99	420.95	475.04	768.64	693.80	563.16
#2热泵	358.60	391.78	448.39	987.37	885.38	716.81
#3案例	386.69	459.01	630.02	803.70	570.79	73.78
#3低零	713.19	778.70	896.37	-688.77	-726.56	-834.60
#3高背	408.82	481.37	647.16	664.70	455.65	8.73
#3热泵	382.98	454.72	623.53	826.76	593.24	99.91