基于RC318的铝电解槽侧壁余热发电系统的设计与实验分析

doi:10.11949/0438-1157.20251012

摘要/Abstract

摘要：

为评估ORC技术回收铝电解槽侧壁余热的可行性，本文设计并搭建了一套中温余热 ORC 现场实验系统，选用工质 RC318，在完全密封与可回收条件下开展实验研究。通过调控蒸发温度、冷凝温度及工质与冷却水流量，系统研究了关键运行参数对循环性能的影响规律。实验结果表明：系统性能主要由蒸发端与冷凝端的热力匹配决定，随着蒸发温度的升高净输出功和热效率增大，而冷凝温度升高则会显著降低系统性能。当蒸发温度接近工质的临界区时，性能提升呈现明显的边际递减特征。蒸发器是系统中不可逆损失最集中的部分，其㶲损随蒸发温度变化呈先下降、后趋于平缓的规律性趋势。过热度对整体性能的贡献有限，其影响主要体现在低蒸发温度区。在本实验条件下，膨胀机的最大输出功率为 9.5kW，循环热效率和㶲效率分别为 8.8% 和 33.96%。

关键词: 有机朗肯循环, 铝电解槽, 实验, 余热回收, 热力性能分析

Abstract:

To evaluate the feasibility of applying Organic Rankine Cycle (ORC) technology to recover the sidewall waste heat of aluminum reduction cells, a field-scale medium-temperature ORC experimental system was designed, constructed, and tested. In the system, RC318 was selected as working fluid, and all experiments were conducted under fully sealed and recoverable operating conditions. By adjusting the evaporation temperature, condensation temperature, and the mass flow rates of both the working fluid and cooling water, the influences of key operating parameters on cycle performance were systematically investigated. The experimental results show that system performance is primarily governed by the thermodynamic matching between the evaporation and condensation processes. As the evaporation temperature increases, both the net power output and thermal efficiency improve, whereas an increase in condensation temperature leads to a significant deterioration in performance. When the evaporation temperature approaches the critical region of the working fluid, the performance enhancement exhibits a pronounced diminishing-marginal-returns behavior. The evaporator is identified as the component with the highest irreversibility within the system, with its exergy destruction first decreasing and then gradually leveling off as the evaporation temperature rises. The contribution of superheat degree to overall performance is limited, with noticeable effects primarily observed at low evaporation temperatures. Under the present experimental conditions, the maximum expander output power is 9.5 kW, and the cycle thermal efficiency and exergy efficiency are 8.8% and 33.96%, respectively.

Key words: ORC, aluminum reduction cell, experimental, waste heat recovery, thermodynamic

中图分类号:

TK 123

明勇, 苏文, 余亚雄, 肖珍. 基于RC318的铝电解槽侧壁余热发电系统的设计与实验分析[J]. 化工学报, DOI: 10.11949/0438-1157.20251012.

Yong MING, Wen SU, Yaxiong YU, Zhen XIAO. Design and experimental analysis for waste heat power generation system from aluminum reduction cell's sidewalls based on RC318 working fluid[J]. CIESC Journal, DOI: 10.11949/0438-1157.20251012.

图/表 23

图1 结构和工作流程图

Fig. 1 Schematic diagram of system configuration and operating principle

图2 T-S图

Fig.2 temperature vs entropy

表1 系统组件的不可逆损失

Table 1 Irreversible losses of system components

组件	不可逆损失
蒸发器	$I e v a p = m f T 0 (s 4 - s 2) - h 4 - h 2 T m h$
工质泵	$I p u m p = m f T 0 (s 2 - s 1)$
冷凝器	$I c o n = m f T 0 (s 1 - s 5) - h 1 - h 5 T m w$
膨胀机	$I e x p = m f T 0 (s 5 - s 4)$

表1 系统组件的不可逆损失

Table 1 Irreversible losses of system components

组件	不可逆损失
蒸发器	$I e v a p = m f T 0 (s 4 - s 2) - h 4 - h 2 T m h$
工质泵	$I p u m p = m f T 0 (s 2 - s 1)$
冷凝器	$I c o n = m f T 0 (s 1 - s 5) - h 1 - h 5 T m w$
膨胀机	$I e x p = m f T 0 (s 5 - s 4)$

表 2 典型测点温度波动统计结果

Table 2 Statistical results of temperature fluctuation at typical measuring points

测点编号	工况	平均温度 / ℃	最大 / 最小 / ℃	波动幅度 / ℃	标准差 / ℃
#3	加装前	250	254 / 246	± 4	1.4
#8	加装前	259	264 / 255	± 4	1.3
#12	加装前	268	272 / 265	± 3	1.0
#3	加装后	161	163 / 159	± 2	0.8
#8	加装后	158	160 / 156	± 2	0.7
#12	加装后	155	157 / 153	± 2	0.7

表3 系统设计计算的基准参数

Table 3 Basic design parameters used for system calculation

参数	数值	说明
蒸发压力/MPa	小于3	保证现场实验安全
冷凝压力/MPa	大于0.1	防止系统在负压下运行
冷却水温度/℃	20-30	板式冷凝器入口
热源入口温度/℃	120 (典型)	侧壁导热油出口
膨胀机等熵效率	0.75	实测经验值
泵等熵效率	0.6	常规小型泵性能
环境温度/K	293	基准温度
供热量/kW	112	热源额定输入

表4 各工质在相同工况下的循环性能比较

Table 4 Comparison of cycle performance of different working fluids under the same operating conditions

工质	临界温度(°C)	临界压力(MPa)	循环热效率(%)	净输出功(kW)	压比
R123	183.7	3.67	8.92	9.99	4.1
R141b	204.3	4.25	8.71	9.75	3.8
R245fa	154.0	3.65	9.16	10.26	4.5
R236fa	124.9	3.19	9.44	10.58	4.6
R1233zd-E	165.6	3.57	9.01	10.09	4
RC318	115.2	2.78	9.81	10.99	5.3

图3 侧壁换热单元结构

Fig.3 Structure of the sidewall heat-exchange unit

表5 板翅式换热单元设计结果

Table 5 Design results of the plate-fin heat-exchange unit

参数	数值
外壳尺寸/mm	660×340×8（高×宽×厚）
翅片类型	错齿形
翅片尺寸/mm	610×(155×2片)×7
当量直径/mm	2.6
内板壁尺寸/mm	660×340×0.5
外板壁尺寸/mm	666×(163×2片)×0.5
接管尺寸/mm	DN10
翅间流速/m·s^-1	0.26

表6 蒸发器的主要结构参数

Table 6 Main structural parameters of the evaporator

参数	数值
管外径/mm	16
管壁厚度/mm	2
中心距/mm	20
单管长度/mm	3000
壳体直径/mm	273
管程数	1
管数	122
管束布置	正三角形

图4 电解槽侧壁余热发电系统组成原理图

Fig.4 Schematic of the sidewall waste-heat power-generation system for aluminum reduction cell

表7 冷凝器1的主要结构参数

Table 7 Main structural parameters of Condenser 1

参数	数值
板片厚度/mm	0.5
板片数目/片	53
板片宽度/mm	250
板片高度/mm	610
单板片面积/m²	0.129
板片间距/mm	3.6
水平孔间距/mm	162
垂直孔间距/mm	516

表8 冷却器2的主要结构参数

Table 8 Main structural parameters of Condenser 2

参数 (单位)	数值
板片厚度/mm	0.5
板片数目/片	9
板片宽度/mm	250
板片高度/mm	610
单板片面积/m2	0.129
板片间距/mm	5.4
水平孔间距/mm	162
垂直孔间距/mm	516

图5 实验系统现场安装照片

Fig.5 On-site installation of the experimental system

表 9 现场实验主要测量仪表及精度

Table 9 Main on-site test instruments and their accuracies

测量参数	仪表	型号	测量范围	误差
温度	热电阻	WSP	0～300 ℃	±0.1% 量程
压力	扩散硅压力变送器	SD2088	0～2 MPa	±0.5% 量程
管道压力	压力表	Y-100	0～2 MPa	±1.6% 量程
工质流量	涡轮流量计	LWGY-C	0.1～1.5 m³·h⁻¹	±0.5% 量程
冷却水流量	法兰式水表	LX-15	0～5 m³·h⁻¹	±2% 量程
转速	转速传感器	DK510	0～99999 rpm	±1 rpm
电流	电流传感器	SIN-DJI-A	0～20 A	±0.1% 量程
电压	电压传感器	MIK-DJU-500	0～500 V	±0.1% 量程

表10 系统主要性能参数不确定性分析结果

Table 10 Uncertainty analysis results of the main system performance parameters

性能指标	主要影响因子	相对不确定度 / %
净输出功率 (W_net)	电压、电流	±0.14
热输入功率 (Q_e)	温差、流量	±2.2
热效率 (η_th)	W_net, Q_e	±3.0
㶲效率 (η_ex)	多温度参数	±3.5

表11 实验性能参数的不确定度计算结果

Table 11 Summary of main performance parameters and their uncertainties

项目	平均值	相对不确定度	绝对不确定度	单位
净输出功率	9.50	±0.14%	±0.013	kW
热输入功率	110.59	±3.5%	±3.9	kW
热效率	8.59	±3.0%	±0.26	%

表 12 系统各状态点的实验测量参数（稳态平均值）

Table 12 Experimental parameters of state points under steady-state operation

状态点	温度/℃	压力/MPa	焓值/kJ·kg^-1	状态说明
1	32.4	2.08	235.6	泵出口，过冷液态
2	102.1	2.03	376.45	蒸发器出口 / 膨胀机入口，轻微过热气态
3	62.55	0.38	360.49	膨胀机出口 / 冷凝器入口，湿蒸汽
4	31.6	0.35	263.08	冷凝器出口 / 泵入口，饱和液态

图6 净输出功随蒸发温度与冷凝温度的变化

Fig. 6 Variation of net output power with evaporating and condensing temperatures

图7 热效率随蒸发温度与冷凝温度的变化

Fig. 7 Variation of thermal efficiency with evaporating and condensing temperatures

图8 㶲效率随蒸发温度与冷凝温度的变化

Fig. 8 Variation of exergy efficiency with evaporating and condensing temperatures

图9 过热度对热效率和净输出功率的影响

Fig. 9 Effect of the degree of superheat on thermal efficiency and net power output

图10 系统各部件㶲损失随蒸发温度的变化

Fig.10 Exergy destruction of system components versus evaporating temperature

表13 理论计算与实验结果对比

Table 13 Comparison between theoretical calculations and experimental results

工况编号	蒸发温度 / ℃	冷凝温度 / ℃	理论净输出功 / kW	实验净输出功 (kW)	相对误差 (%)	理论热效率 /%	实验热效率 (%)	相对误差 (%)
1	70	30	7.18	6.83	–4.9	6.41	6.10	–4.8
2	70	35	6.51	6.00	–7.8	5.81	5.40	–7.1
3	70	40	5.65	5.20	–8.0	5.04	4.65	–7.7
4	70	45	4.77	4.40	–7.8	4.26	3.95	–7.3
5	75	30	7.79	7.36	–5.5	6.96	6.60	–5.2
6	75	35	7.14	6.50	–7.7	6.38	5.73	–7.3
7	75	40	6.32	5.85	–7.4	5.64	5.23	–7.3
8	75	45	5.48	5.05	–7.8	4.89	4.50	–8.0
9	80	30	8.35	7.80	–6.6	7.45	6.97	–6.4
10	80	35	7.72	7.15	–7.4	6.89	6.37	–7.6
11	80	40	6.93	6.40	–7.7	6.18	5.70	–7.8
12	80	45	6.13	5.65	–7.8	5.47	5.00	–8.6
13	85	30	8.86	8.25	–6.9	7.91	7.36	–7.0
14	85	35	8.25	7.63	–7.5	7.36	6.82	–7.3
15	85	40	7.48	6.95	–7.1	6.68	6.22	–6.9
16	85	45	6.71	6.20	–7.6	5.99	5.52	–7.8
17	90	30	9.32	8.64	–7.3	8.32	7.71	–7.3
18	90	35	8.73	8.05	–7.8	7.79	7.20	–7.6
19	90	40	7.99	7.35	–8.0	7.13	6.55	–8.1
20	90	45	7.24	6.65	–8.2	6.46	5.95	–7.9
21	95	30	9.74	8.99	–7.7	8.69	8.02	–7.7
22	95	35	9.16	8.46	–7.6	8.18	7.57	–7.4
23	95	40	8.44	7.78	–7.8	7.54	6.96	–7.7
24	95	45	7.72	7.10	–8.0	6.89	6.35	–7.8
25	100	30	10.13	9.29	–8.3	9.05	8.31	–8.2
26	100	35	9.57	8.76	–8.5	8.54	7.82	–8.4
27	100	40	8.87	8.15	–8.1	7.91	7.25	–8.3
28	100	45	8.16	7.47	–8.5	7.28	6.65	–8.6
29	105	30	10.48	9.50	–8.9	9.36	8.53	–8.9
30	105	35	9.93	9.05	–8.9	8.86	8.07	–8.9
31	105	40	9.24	8.40	–9.1	8.25	7.49	–9.2
32	105	45	8.55	7.77	–9.1	7.63	6.93	–9.2

参考文献 32

[1]	Zhou N J, Wang X Y, Chen Z, et al. Experimental study on Organic Rankine Cycle for waste heat recovery from low-temperature flue gas[J]. Energy, 2013, 55: 216-225.
[2]	王志奇, 贺妮, 罗兰, 等. 水平管内R245fa/R141b沸腾换热特性的实验研究[J]. 化工学报, 2020, 71(4): 1588-1596.
	Wang Z Q, He N, Luo L, et al. Experimental investigation on flow boiling heat transfer of R245fa/R141b in horizontal smooth tube[J]. CIESC Journal, 2020, 71(4): 1588-1596.
[3]	陈林, 孙颖颖, 梁江涛, 等. 用于烟气余热回收的塑料翅片管换热器的设计及分析[J]. 化工学报, 2014, 65(S1): 175-179.
	Chen L, Sun Y Y, Liang J T, et al. Design and analysis of plastic fin-tube heat exchanger for flu gas heat recovery[J]. CIESC Journal, 2014, 65(S1): 175-179.
[4]	吴双应, 汪菲, 肖兰. 基于低温烟气余热发电的Kalina循环热经济性能分析[J]. 化工学报, 2017, 68(3): 1170-1177.
	Wu S Y, W F, Xiao L. Thermo-economic performance analysis of Kalina cycle based on low temperature flue gas waste heat power generation[J]. CIESC Journal, 2017, 68(3): 1170-1177.
[5]	Zakeralhoseini S, Schiffmann J. Design, computational and experimental investigation of a small-scale turbopump for organic Rankine cycle systems[J]. Energy Conversion and Management, 2023, 287: 117073.
[6]	Kolasinski P. Experimental and modelling studies on the possible application of heat storage devices for powering the ORC (Organic Rankine Cycle) systems[J]. Thermal Science and Engineering Progress, 2020, 19: 100586.
[7]	Li X L, Lecompte S, Van Nieuwenhuyse J, et al. Experimental investigation of an organic Rankine cycle with liquid-flooded expansion and R1233zd(E) as working fluid[J]. Energy Conversion and Management, 2021, 234:113894.
[8]	Ottaviano S, Poletto C, Ancona M A, et al. Experimental investigation on micro-ORC system operating with partial evaporation and two-phase expansion[J]. Energy Conversion and Management, 2022, 274: 116415.
[9]	Moradi R, Villarini M, Cioccolanti L. Experimental modeling of a lubricated, open drive scroll expander for micro-scale organic Rankine cycle systems[J]. Applied Thermal Engineering, 2021, 190: 116784.
[10]	黄国瑞, 赵耀, 谢明熹, 等. 一种新型数据中心余热回收系统实验与分析[J]. 化工学报, 2025,76(S1): 409-417.
	Huang G R, Zhao Y, Xie M X, et al. Experimental study on a novel waste heat recovery system based on desiccant coated exchanger in data center[J]. CIESC Journal, 2025, 76(S1): 409-417.
[11]	董泽明, 娄聚伟, 王楠, 等. 含余热回收的超临界压缩二氧化碳储能系统热力学特性研究[J]. 化工学报, 2025, 76(7): 3477-3486.
	Dong Z M, Lou J W, Wang N, et al. Research on thermodynamic properties of supercritical compressed carbon dioxide energy storage system with waste heat recovery[J]. CIESC Journal, 2025, 76(7): 3477-3486.
[12]	Barzi Y M, Assadi M, Arvesen H M, et al. A Nonel heat recovery technology from An aluminum reduction cell side walls: experimental and theoretical investigations[J]. Light Metals, 2014: 733-738.
[13]	Yang Y J, Tao W J, Wang Z W, et al. A Numerical Approach on Waste Heat Recovery through Sidewall Heat-Exchanging in an Aluminum Electrolysis Cell[J]. Advances in Materials Science and Engineering, 2021, 2021: 3573306.
[14]	Ming Y, Zhou N J. Thermodynamic Performance Analysis of a Waste Heat Power Generation System (WHPGS) Applied to the Sidewalls of Aluminum Reduction Cells[J]. Entropy, 2020, 22(11): 1279.
[15]	Allard F, Desilets M, LeBreux M, et al. Improved heat transfer modeling of the top of aluminum electrolysis cells[J]. International Journal of Heat and Mass Transfer, 2019, 132: 1262-1276.
[16]	Khafajah H I, Abdelsamie M M, Mohamed Ali M I. Techno-economic assessment of waste heat harnessing in the primary aluminum industry through a dual-stage organic Rankine cycle integration[J]. Energy, 2024, 313:133952.
[17]	梁高卫. 基于热电转换的铝电解槽侧壁余热发电研究[D]. 长沙:中南大学,2013.
	Liang G W. Research on power generation of waste heat recovery from aluminum reduction cell's sidewalls based on thermoelectric conversion[D]. Changsha, Central South University, 2013.
[18]	王金江, 鲁振杰, 安维峥, 等. ORC 发电系统工艺过程预警诊断技术研究与展望[J].化工学报, 2025, 76(7): 3137-3152.
	Wang J J, Lu Z J, An W Z, et al. Research and prospect of early warning and diagnosis technology for ORC power generation system process[J]. CIESC Journal, 2025, 76(7): 3137-3152.
[19]	闫沛伟, 张曼铮, 肖猛, 等. 地热能有机朗肯循环系统控制策略研究[J]. 化工学报, 2023, 74(12): 4810-4819.
	Yan P W, Zhang M Z, Xiao M, et al. Study on the control strategy of a geothermal organic Rankine cycle system[J]. CIESC Journal, 2023, 74(12): 4810-4819.
[20]	党玉荣, 莫春兰, 史科锐, 等. 综合评价模型联合遗传算法的混合工质ORC 系统性能研究[J]. 化工学报, 2023, 74(5): 1884-1895.
	Dang Y R, Mo C L, Shi K R, et al. Comprehensive evaluation model combined with genetic algorithm for the study on the performance of ORC system with zeotropic mixture[J]. CIESC Journal, 2023, 74(5): 1884-1895.
[21]	Javed S, Tiwari A K. Performance assessment of different Organic Rankine Cycle (ORC) configurations driven by solar energy[J]. Process Safety and Environmental Protection, 2023, 171: 655-666.
[22]	Sun Z X, Lai J P, Wang S J, et al. Thermodynamic optimization and comparative study of different ORC configurations utilizing the exergies of LNG and low grade heat of different temperatures[J]. Energy, 2018, 147:688-700.
[23]	曹健, 冯新, 吉晓燕,等. 基于混合工质的多级蒸发ORC 理论极限性能研究[J]. 化工学报, 2021, 72(7): 3780-3787.
	Cao J, Feng X, Ji X Y, et al. Study on the theoretical limit performance of multi-pressure evaporation ORC based on zeotropic mixture[J]. CIESC Journal, 2021, 72(7): 3780-3787.
[24]	戴文智, 沈雄健, 宋晓博, 等. 生物质双级蒸发双回热有机朗肯循环系统环境分析[J]. 化工学报, 2025, 76(3): 1230-1242.
	Dai W Z, Shen X J, Song X B, et al. Environmental analysis of biomass double-stage evaporation doubleregenerative organic Rankine cycle system[J]. CIESC Journal, 2025, 76(3): 1230-1242.
[25]	张曼铮, 肖猛, 闫沛伟, 等. 危废焚烧处理耦合有机朗肯循环系统工质筛选与热力学优化[J]. 化工学报, 2023, 74(8): 3502-3512.
	Zhang M Z, Xiao M, Yan P W, et al. Working fluid screening and thermodynamic optimization of hazardous waste incineration coupled organic Rankine cycle system[J]. CIESC Journal, 2023, 74(8): 3502-3512.
[26]	Li Z, Yu X L, Wang L, et al. Comparative investigations on dynamic characteristics of basic ORC and cascaded LTES-ORC under transient heat sources[J]. Applied Thermal Engineering, 2022, 207: 118197.
[27]	Sadeghi M, Nemati A, Ghavimi A, et al. Thermodynamic analysis and multi- objective optimization of various ORC (organic Rankine cycle) configurations using zeotropic mixtures. Energy, 2016, 109: 791-802.
[28]	Chagnon-Lessard T, Mathieu-Potvin F, Gosselin L. Optimal design of geothermal power plants: a comparison of single-pressure and dual-pressure organic Rankine cycles[J]. Geothermics. 2020, 86: 101787.
[29]	Wang Q L, Wang J Q, Li T L, et al. Techno-economic performance of two-stage series evaporation organic Rankine cycle with dual-level heat sources[J]. Applied Thermal Enginerring, 2020, 171: 115078.
[30]	Lemmon EW, Huber ML, Mclinden MO. NIST Standard ReferenceDatabase 23: reference fluid thermodynamic and transport properties-REFPROP. 9.0; 2010.
[31]	Su W, Hwang Y, Deng S, et al. Thermodynamic performance comparison of Organic Rankine Cycle between zeotropic mixtures and pure fluids under open heat source[J]. Energy Conversion and Management, 2018, 166: 720-737.
[32]	Essadik M, Hajabdollahi Ouderji Z, Yu Z B. Combined exergy-pinch point analysis of a multi-valve flexible heat pump with integrated latent thermal energy storage for defrosting operation[J]. International Journal of Refrigeration, 2025, 176: 254-267.