基于膨胀机-热泵（st-hp）的大型吸收式热电联产机组集中供热方法

doi:10.16085/j.issn.1000-6613.2019-0710

摘要/Abstract

摘要：

提出基于螺杆膨胀机-热泵（st-hp）的热电联产供热方法来挖掘汽水系统的余热余压利用潜力，实现了更好的节能效果和更高的供热功率，基于热力学第二定律和理论对主要新增元件在变工况下进行了?分析和分析。通过让中压缸排汽“余压发电、余热采暖”的手段提高集中供热能力；利用算法设计热力站处吸收式换热装置以提升一次热供回网水温差，并予以模型验证；以某600MW机组为算例，利用Ebsilon软件分析变工况下电厂侧新增主要供热元件效率和效率。结果表明：st-hp系统不仅能在不增加市政热网运输管径和机组出力的同时使供热量提高50%，而且满足部分厂用电需求；吸收式热泵和尖峰加热器的节能研究重点是提高热力循环的完善程度以减少?损；螺杆膨胀机和尖峰加热器应着重于提高传热过程中工质的速度场和温度场协同程度。运行工况对机组热经济性影响很大，热负荷不同时，发电煤耗率极差极小值和极大值分别为-5g/(kW·h)和22.97g/(kW·h)。

关键词: 热力学, 热电联产, 余热余压利用, ?效率, 效率, 传热, 模型

Abstract:

This paper proposed a screw turbine-heat pump (st-hp) cogeneration heat supply method to exploit the residual heat and pressure utilization potential of the steam-water system to achieve better energy-saving effect and higher heating power. Based on the second law of thermodynamics and the theory of entranspy, the exergy and entranspy analysis of the main newly added components under variable operating conditions were carried out. Using the IPC exhausting, the heating capacity was improved by means of “extra pressure for electric and residual heat for heating”. Absorption heat exchanger located in the thermal station was designed by algorithm to enlarge the temperature difference of the network water and the model was verified. A 600MW unit was used as an example to analyze the exergy and entranspy efficiency of new main heating elements in the power plant side under variable operating conditions using Ebsilon software. The results showed that st-hp system can not only increase the heat capacity of the municipal heat network by 50% without enlarging output of the boiler, but also meet the part demand of the plant. The energy-saving research of absorption heat pump and peak heater shall focus on improving the perfection of thermal cycle to reduce exergy loss. Screw turbine and peak heater should focus on improving the coordinative degree of working fluid velocity field and temperature field in heat transfer process. The operating conditions have a great influence on the thermal economy of the unit. When the thermal load is different, the minimum and maximum values of coal consumption for power generation are -5g/(kW·h) and 22.97g/(kW·h) respectively.

Key words: thermodynamics, cogeneration, waste heat and pressure utilization, exergy efficiency, entranspy efficiency, heat transfer, model

中图分类号:

TK123

刘浩晨,耿直,顾煜炯. 基于膨胀机-热泵（st-hp）的大型吸收式热电联产机组集中供热方法[J]. 化工进展, 2020, 39(2): 468-477.

Haochen LIU,Zhi GENG,Yujiong GU. Central heating supply method of large scale absorption CHP based on st-hp[J]. Chemical Industry and Engineering Progress, 2020, 39(2): 468-477.

图/表 12

图1 传统热电联产方案图

图2 基于st-hp的吸收式热电联产机组简图

图3 吸收式换热装置数学模型

图4 螺杆膨胀机数学模型

表1 模型数据对比

参数	文献[6]	本文	绝对误差	相对误差/%
热力站一次热网水供水温度/℃	130	115	15.00	11.54
一次热网水回水温度/℃	25	25	0.00	0.00
二次热网回水温度/℃	48	45	3.00	6.25
二次热网供水温度/℃	60	68	8.00	13.33
电厂侧单效吸收式热泵COP	1.75	1.68	0.07	4.00
热网供热能力提高的份额/%	75.0	66.6	8.33	11.11

图5 吸收式换热装置在Matlab中的计算流程

图6 在Ebsilon仿真界面中电厂侧的st-hp工艺流程

表2 设计工况下st-hp系统的技术参数

序号	项目	流量/t·h^-1	温度/℃	压力/MPa	比焓/kJ·kg^-1
1	锅炉主蒸汽	1782.0	566.0	24.200	3398.8
2	锅炉再热蒸汽	1521.1	566.0	3.769	3598.9
3	中压缸排汽	1302.5	373.2	1.059	3206.4
4	用于采暖的中压缸排汽抽汽	302.3	373.2	1.059	3206.4
5	螺杆膨胀机进汽	43.2	373.2(t_i)	1.059	3206.4
6	螺杆膨胀机排汽	43.2	183.2(t_o)	0.200	2836.9
7	热泵发生器驱动热源出口水	43.2	120.0(T_g,o)	0.005	83.9
8	尖峰加热器蒸汽热源进口	259.1	373.2(T_r,i)	1.059	3206.4
9	尖峰加热器热源冷凝水出口	259.1	182.4(T_r,o)	1.059	773.8
10	一次热网回水	1980.0	20.0(T_a,i)	0.120	84.0
11	一次热网水中间点	1980.0	44.2(T_c,o)	0.120	185.0
12	尖峰加热器一次热网水进口	1980.0	44.2(T_l,i)	0.800	185.9
13	尖峰加热器一次热网水出口	1980.0	120.0(T_l,o)	0.800	504.2
14	热泵蒸发器低温热源入口水	1872.0	31.0	0.100	130.0
15	热泵蒸发器低温热源出口水	1872.0	20.7	0.100	86.7

表3 设计工况下吸收式换热装置技术参数

序号	项目	流量/t·h^-1	温度/℃	压力/MPa	比焓/kJ·kg^-1
1	一次热网供水	1998.0	115.0(t₃)	0.78	483.03
2	进换热器的一次热网供水	1998.0	85.0(t₂)	0.78	356.58
3	出换热器的一次热网供水	1998.0	50.0(t₁)	0.78	210.00
4	一次热网回水	1998.0	25.0(t₀)	0.78	105.55
5	二次热网回水	7818.3	45.0( $t 0'$ )	0.65	188.99
6	进换热器的二次热网回水	2325.6	45.0( $t 0'$ )	0.65	188.99
7	出换热器的二次热网回水	2325.6	75.0( $t 4'$ )	0.65	314.52
8	二次热网供水	7818.3	68.0( $t 3'$ )	0.65	285.19
9	进热泵吸收器的二次热网回水	5492.7	45.0	0.65	188.99
10	进热泵冷凝器的二次热网回水	5492.7	60.0( $t 1'$ )	0.65	251.71
11	出热泵冷凝器的二次热网回水	5492.7	65.0( $t 2'$ )	0.65	272.63

表3 设计工况下吸收式换热装置技术参数

序号	项目	流量/t·h^-1	温度/℃	压力/MPa	比焓/kJ·kg^-1
1	一次热网供水	1998.0	115.0(t₃)	0.78	483.03
2	进换热器的一次热网供水	1998.0	85.0(t₂)	0.78	356.58
3	出换热器的一次热网供水	1998.0	50.0(t₁)	0.78	210.00
4	一次热网回水	1998.0	25.0(t₀)	0.78	105.55
5	二次热网回水	7818.3	45.0( $t 0'$ )	0.65	188.99
6	进换热器的二次热网回水	2325.6	45.0( $t 0'$ )	0.65	188.99
7	出换热器的二次热网回水	2325.6	75.0( $t 4'$ )	0.65	314.52
8	二次热网供水	7818.3	68.0( $t 3'$ )	0.65	285.19
9	进热泵吸收器的二次热网回水	5492.7	45.0	0.65	188.99
10	进热泵冷凝器的二次热网回水	5492.7	60.0( $t 1'$ )	0.65	251.71
11	出热泵冷凝器的二次热网回水	5492.7	65.0( $t 2'$ )	0.65	272.63

图7 变工况下各元件效率

图8 变工况下各元件效率

图9 不同工况下发电煤耗极差随热网水质量流量变化关系

参考文献 40

1	清华大学建筑节能研究中心. 中国建筑节能年度发展研究报告2018[M]. 北京: 中国建筑工业出版社, 2018: 27-30.
	Building Energy Conservation Research Center, University Tsinghua. 2018 Annual report on China building energy efficiency[M]. Beijing: China Architecture & Building Press, 2018: 27-30.
2	清华大学建筑节能研究中心. 中国建筑节能年度发展研究报告2019[M]. 北京: 中国建筑工业出版社, 2019: 13-17.
	Building Energy Conservation Research Center, University Tsinghua. 2019 Annual report on China building energy efficiency[M]. Beijing: China Architecture & Building Press, 2019: 13-17.
3	杨倩鹏, 林伟杰, 王月明, 等. 火力发电产业发展与前沿技术路线[J]. 中国电机工程学报, 2017, 37(13): 3787-3794.
	YANG Q P, LIN W J, WANG Y M, et al. Industry development and frontier technology roadmap of thermal power generation[J]. Proceedings of the CSEE, 2017, 37(13): 3787-3794.
4	国家能源局. 2017年全国电力可靠性年度报告[EB/OL]. [2018-06-06]. https: //mp. weixin. qq. com/s/ZIaxJVkib7Y5W1aCPIrguw.
5	刘强, 段远源. 超临界600MW火电机组热力系统的㶲分析[J]. 中国电机工程学报, 2010, 30(32): 8-12.
	LIU Q, DUAN Y Q. Exergy analysis for thermal power system of a 600 MW supercritical power unit[J]. Proceedings of the CSEE, 2010, 30(32): 8-12.
6	张世钢, 付林, 李世一, 等. 赤峰市基于吸收式换热的热电联产集中供热示范工程[J]. 暖通空调, 2010, 40(11): 71-75.
	ZAHNG S G, FU L, LI S Y, et al. Demonstration project of district heating system with cogeneration based on absorption heat exchange (co-ah cycle) in Chifeng City[J]. HV&AC, 2010, 40(11): 71-75.
7	LUND H, WERNER S, WILTSHIRE R, et al. 4th Generation district heating (4GDH) integrating smart thermal grids into future sustainable energy systems[J].Energy, 2014, 68: 1-11.
8	BUFFAT R, RAUBAL M. Spatio-temporal potential of a biogenic micro CHP swarm in Switzerland[J]. Renewable and Sustainable Energy Reviews, 2019, 103: 443-454.
9	GVOZDENAC D, UROŠEVICA B G, MENKE C. High efficiency cogeneration: CHP and non-CHP energy[J]. Energy, 2017, 135: 269-278.
10	江亿, 付林. 对热电联产能耗分摊方式的一点建议[J]. 中国能源, 2016, 38(3): 5-8.
	JIANG Y, FU L. A suggestion on the sharing method of cogeneration energy consumption[J]. Energy of China, 2016, 38(3): 5-8.
11	付林, 江亿, 张世钢. 基于Co-ah循环的热电联产集中供热方法[J]. 清华大学学报, 2008, 48(9): 1377-1380.
	FU L, JIANG Y, ZHANG S G. District heating system based on Co-ah cycles in combined heating and power systems[J]. Journal of Tsinghua University (Science and Technology), 2008, 48(9): 1377-1380.
12	林振娴, 杨勇平, 何坚忍. 热网加热器在热电联产系统中的全工况分析[J]. 中国电机工程学报, 2010, 30(23): 14-18.
	LIN Z X, YANG Y P, HE R J. Analysis on the full conditions of thermal-system heater in the combined and heat power system[J]. Proceedings of the CSEE, 2010, 30(23): 14-18.
13	戈志华, 孙诗梦, 万燕, 等. 大型汽轮机组高背压供热改造适用性分析[J]. 中国电机工程学报, 2017, 37(11): 3216-3223.
	GE Z H, SUN S M, WAN Y, et al. Applicability analysis of high back-pressure heating retrofit for large-scale steam turbine unit[J]. Proceedings of the CSEE, 2017, 37(11): 3216-3223.
14	杨志平, 时斌, 李晓恩, 等. 热负荷分配比例对抽凝-背压供热机组能耗影响[J]. 化工进展, 2018, 37(3): 875-883.
	YANG Z P, SHI B, LI X N, et al. Impacts of heat load distribution ratio on energy consumption of extraction steam- high back pressure heating cogeneration unit[J]. Chemical Industry and Engineering Progress, 2018, 37(3): 875-883.
15	时斌, 王宁玲, 李晓恩, 等. 供水温度对高背压热电联产系统能耗水平的影响[J]. 化工进展, 2018, 37(1): 96-104.
	SHI B, WANG N L, LI X E, et al. Impacts of water supply temperature on energy consumption of high back pressure cogeneration system[J]. Chemical Industry and Engineering Progress, 2018, 37(1): 96-104.
16	赵文沛. 供热余压余热利用技术在某电厂300MW机组的应用研究[D]. 保定: 华北电力大学, 2018.
	ZHAO W P. The research on using residual pressure and after-heat recovery technology in 300MW power unit[D]. Baoding: North China Electric Power University, 2018.
17	孙维理, 蒋东来. 一种蒸压釜余热、余压给锅炉软水加热、升温装置: CN 208382128 U[P]. 2019-01-15.
	SUN Weili, JIANG Donglai. Heat exchanger and residual pressure of autoclave for soft water heating of boiler and heating device: CN 208382128 U[P]. 2019-01-15.
18	顾煜炯, 耿直, 谢典, 等. 电厂循环冷却水余热利用分析[J]. 热力发电, 2016, 45(4): 35-40.
	GU Y J, GENG Z, XIE D, et al. Waste heat recovery from circulating cooling water in power plant[J]. Thermal Power Generation, 2016, 45(4): 35-40.
19	郭中旭, 戈志华, 赵世飞, 等. 耦合吸收式热泵机组变工况分析[J]. 热能动力工程, 2018, 33(2): 25-32.
	GUO Z X, GE Z H, ZHAO S F, et al. Analysis of the off-design operation conditions of a coupled absorption type heat pump unit[J]. Journal of Engineering for Thermal Energy and Power, 2018, 33(2): 25-32.
20	WU Xianli, HU Yangdong, WU Lianying. Model and design of cogeneration system for different demands of desalination water, heat and power production[J]. Chinese Journal of Chemical Engineering, 2014, 22(3): 330-338.
21	张曙. 工业4.0和智能制造[J]. 机械设计与制造工程, 2014, 43(8): 1-5.
	ZAHNG S. The industry 4.0 and intelligent manufacturing[J]. Machine Design and Manufacturing Engineering, 2014, 43(8): 1-5.
22	刘鑫屏, 田亮, 王琪, 等. 供热机组发电负荷-机前压力-抽汽压力简化非线性动态模型[J]. 动力工程学报, 2014, 34(2): 115-121.
	LIU X P, TIAN L, WANG Q, et al. Simplified nonlinear dynamic model of generation load-throttle pressure-extraction pressure for heating units[J]. Journal of Chinese Society of Power Engineering, 2014, 34(2): 115-121.
23	张立钦, 苗青, 唐道轲, 等. 电热泵降低一次网回水温度的应用分析与实验[J]. 区域供热, 2017(2): 1-4.
	ZAHNG L Q, MIAO Q, TANG D K, et al. Application analysis and experiment of electric heat pump to reduce backwater temperature of primary network[J]. District Heating, 2017(2): 1-4.
24	WANG Xiaoyin, ZHAO Xiling, FU Lin. Entransy analysis of secondary network flow distribution in absorption heat exchanger[J]. Energy, 2018, 147: 428-439.
25	杨立军, 杜小泽, 杨勇平. 空冷凝汽器全工况运行特性分析[J]. 中国电机工程学报, 2008, 28(8): 24-28.
	YANG L J, DU X Z, YANG Y P. Performance analysis of air-cooled condensers at all operating conditions[J]. Proceedings of the CSEE, 2008, 28(8): 24-28.
26	HAMED H, ABDULHAMID N M A, SAEID N. Mathematical modeling and validation of a 320 MW tangentially fired boiler: a case study[J]. Applied Thermal Engineering, 2019, 146: 232-242.
27	CELIS C, PINTO GUSTAVO R S, TEIXEIRA T, et al. A steam turbine dynamic model for full scope power plant simulators[J]. Applied Thermal Engineering, 2017, 120: 593-602.
28	张益波, 任佳, 潘海鹏, 等. 一类热定型机换热器的动态建模方法[J]. 化工学报, 2011, 62(8): 2360-2366.
	ZHANG Y B, REN J, PAN H P, et al. A kind of dynamic modeling method for heat-exchanger of heat-setting machine[J]. CIESC Journal, 2011, 62(8): 2360-2366.
29	MA Jiaze, WANG Yufei, FENG Xiao. Optimization of multi-plants cooling water system[J]. Energy, 2018, 150: 797-815.
30	沈维道, 童钧耕. 工程热力学[M]. 4版. 北京: 高等教育出版社, 2007: 40.
	SHEN W D, TONG J G. Engineering thermodynamics[M]. 4th ed. Beijing: Higher Education Press, 2007: 40.
31	徐海涛, 桑芝富. 蒸汽喷射器喷射系数计算的热力学模型[J]. 化工学报, 2004, 55(5): 704-710.
	XU H T, SANG Z F. Thermodynamic models for calculating entrainment ratio of steam-jet ejector[J]. Journal of Chemical Industry and Engineering (China), 2004, 55(5): 704-710.
32	成岭, 张婧, 金璐, 等. LiBr-H₂O吸收式热泵的热力学分析[J]. 制冷学报, 2019, 40(2): 128-134.
	CHENG L, ZHANG J, JIN L, et al. Thermodynamic analysis of LiBr-H₂O absorption heat pump[J]. Journal of Refrigeration, 2019, 40(2): 128-134.
33	周少祥, 姜媛媛, 吴智泉, 等. 电厂锅炉单耗分析模型及其应用[J]. 动力工程学报, 2012, 32(1): 59-65.
	ZHOU S X, JIANG Y Y, WU Z Q, et al. Analysis model for unit consumption of power boilers and its application[J]. Journal of Chinese Society of Power Engineering, 2012, 32(1): 59-65.
34	GUO Zengyuan, ZHU Hongye, LIANG Xingang. Entransy—a physical quantity describing heat transfer ability[J]. International Journal of Heat and Mass Transfer, 2007, 50: 2545-2556.
35	夏力, 冯园丽, 项曙光. 理论及其在化工过程节能中的应用进展[J]. 化工学报, 2016, 67(12): 4915-4921.
	XIA L, FENG Y L, XIANG S G. Progress and application of entransy theory in energy saving of chemical processes[J]. CIESC Journal, 2016, 67(12): 4915-4921.
36	赵甜, 陈群. 的宏观物理意义及其应用[J]. 物理学报, 2013, 62(23): 1-7.
	ZHAO T, CHEN Q. Macroscopic physical meaning of entransy and its application[J]. Acta Physica Sinica, 2013, 62(23): 1-7.
37	LI Peifeng, NORD N, ERTESVÅG I S, et al. Integrated multiscale simulation of combined heat and power based district heating system[J]. Energy Conversion and Management, 2015, 106: 337-354.
38	朱泓逻. 基于Ebsilon的火电厂热力系统建模、监测及优化研究[D]. 北京: 清华大学, 2015.
	ZHU H L. The research of modeling, monitoring and optimizing for thermal system of thermal power plant based on Ebsilon[D]. Beijing: Tsinghua University, 2015.
39	王平. 泛在电力物联网时代很快就会到来[N]. 国家电网报, 2019-03-20(001).
	WANG P. The ubiquitous power Internet of Things era will soon come [N]. State Grid News, 2019-03-20(001).
40	徐志明, 王景涛, 王磊, 等. 交叉缩放椭圆管颗粒污垢特性的实验分析[J]. 化工进展, 2014, 33(4): 831-836.
	XU Z M, WANG J T, WANG L, et al. Experimental analysis on particulate fouling characteristics of alternating elliptical axis tube[J]. Chemical Industry and Engineering Progress, 2014, 33(4): 831-836.

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