论文总字数：26944字

摘 要

本课题针对低温烟气余热，建立了回热型有机朗肯低温余热发电系统理论模型，给出了热力计算思路，并进行了实例计算。重点研究了回热度、蒸发温度、蒸发器窄点温差、过热度、冷凝温度、冷凝器窄点温差、过冷度对系统的影响，使用控制变量法，对以上影响因素进行分析，综合技术性指标和经济性指标对系统进行了优化分析，最终确定了最佳运行工况为：

回热度为0.04、蒸发温度为195℃、蒸发器窄点温差为20℃、过热度为12℃、冷凝温度为55℃、冷凝器窄点温差为8℃、过冷度为0℃。

在最佳工况下运行时，系统的净输出功为504.31kW，余热回收量为3975.72kW，循环热效率为13.35%，系统投资成本为564.10万元，系统年发电利润为231.09万元，投资回收期为2.48年。

同时分析结果表明：

提高回热度会增大系统的循环热效率, 同时系统的投资回收期随着回热度的增大先减少后增大。

蒸发温度越高，初期投资成本越低，且系统投资回收期也会缩短。

蒸发器窄点温差越大，系统的经济性越高。

提高过热度会减少初期的投资成本和回收期,且系统回收期也会有相应缩短，但缩短的幅度逐渐趋于平缓。

从经济性角度考虑，冷凝温度取55℃时系统回收期处于经济最佳点。

冷凝器窄点温差对于系统的热力性能无影响，但对于系统的经济性有着较大的影响。

过冷度选取越低越好。

关键词：有机朗肯循环；低温发电；理论模型；优化分析

Performance Analysis of Recuperative Organic Rankine Cycle System for Electric Power Generation with Low Temperature Waste Heat

Abstract

This paper aim at the low temperature flue gas waste heat. Established a theoretical model of the Recuperative Organic Rankine Cycle System for electric power generation with low temperature waste heat. The thermal calculation ideas were given and the examples were calculated. The research focuses on the regenerator effectiveness, evaporation temperature, evaporator narrow point temperature difference, superheat degree, condensation temperature, condenser narrow point temperature difference, and sub superheat effect on the system. Using the control variable method to analyze the above influencing factors, comprehensive technical indicators And the economic indicators to optimize the analysis of the system, and finally determine the best operating conditions:

The regenerator effectiveness is 0.04, the evaporating temperature is 195℃ the evaporator narrow point temperature difference is 20℃, the superheat degree is 12℃, the condensation temperature is 55℃, the condenser narrow point temperature difference is 8℃, and the degree of under cooling is 0℃.

When operating under the best working conditions, the net output power of the system is 504.31kW, the waste heat recovery is 3975.72kW, the cycle thermal efficiency is 13.35%, the system investment cost is 5.641 million yuan, the system annual power generation profit is 2,312,900 yuan, and the system investment recovery period is 2.48 years.

The results show:

1) Increasing the regenerator effectiveness will increase the cycle thermal efficiency of the system, and the investment recovery period of the system will decrease first and then increase with the increase of the heat recovery.

2) The higher the evaporation temperature, the lower the initial investment cost and the shorter the system investment recovery period.

3) The greater the evaporator narrow point temperature difference, the higher the economics of the system.

4) Increasing the degree of superheat will reduce the initial investment cost and the system payback period, and the system payback period will be shortened accordingly, but the shortening will gradually become flat.

5) From the economic point of view, the system recovery period is at the economically optimal point when the condensation temperature is 55℃.

6) Condenser narrow point temperature difference has no effect on the thermal performance of the system, but has a greater impact on the economics of the system.

7) The lower the degree of under cooling ,the better.

Keywords: Organic Rankine Cycle; low temperature power generation; theoretical model; optimization analysis

目录

摘要 I

Abstract III

第一章 绪论 1

1.1 有机朗肯低温余热发电系统概述 1

1.1.1 有机朗肯循环系统 1

1.1.2 低温ORC发电系统的优势 1

1.1.3 有机朗肯循环类别 2

1.2 低温余热ORC发电系统研究现状 2

1.2.1 有机工质优选 3

1.2.2 蒸发器的研究 3

1.2.3 系统参数的优选 3

1.2.4 复杂ORC系统循环的研究 4

1.3 ORC系统的经济性能分析 6

1.4 本课题研究内容 7

第二章 回热型有机朗肯循环系统理论模型建立和计算 8

2.1 回热型有机朗肯循环系统简介 8

2.2 热力计算思路 10

2.2.1 蒸发器热力分析 10

2.2.2 冷凝器热力分析 11

2.2.3 膨胀机热力分析 12

2.2.4 工质泵热力分析 13

2.2.5 回热器热力分析 14

2.2.6 系统整体热力分析 15

2.3 有机工质优选原则 15

2.4 实例计算 15

2.4.1 热源参数 15

2.4.2 有机工质选择 15

2.4.3 初始运行工况确定 16

2.4.4 计算结果 17

2.5 本章小结 20

第三章 系统优化及分析 21

3.1 优化指标及影响因素 21

3.1.1 技术性指标 21

3.1.2 经济性指标 22

3.1.3 影响因素 24

3.2 回热度优化分析 24

3.2.1 技术性指标 25

3.2.2 经济性指标 26

3.3 蒸发温度优化分析 29

3.3.1 技术性指标 29

3.3.2 经济性指标 32

3.4 蒸发器窄点温差优化分析 35

3.4.1 技术性指标 35

3.4.2 经济性指标 37

3.5 过热度优化分析 40

3.5.1 技术性指标 40

3.5.2 经济性指标 42

3.6 冷凝温度优化分析 45

3.6.1 技术性指标 45

3.6.2 经济性指标 47

3.7 冷凝器窄点温差优化分析 50

3.7.1 技术性指标 50

3.7.2 经济性指标 50

3.8 过冷度优化分析 53

3.8.1 技术性指标 53

3.8.2 经济性指标 54

3.9 本章小结 57

第四章 结论与展望 59

4.1 结论 59

4.2 展望 60

参考文献 61

致谢 64

请支付后下载全文，论文总字数：26944字