论文总字数：27037字

摘 要

传统的压缩式制冷会消耗大量的高品位能源，同时压缩式制冷使用的制冷剂会破坏臭氧层，造成温室效应，因而利用低品位能源来制冷是非常有意义的。喷射式制冷就是一种广泛被人看好的低品位能源驱动的制冷方式。

本设计以环戊烷为工质，以热空气为热源，以水为冷源，对喷射式制冷系统过程利用MATLAB R2018b 调用REFPROP 9.1进行数据模拟，计算出工质各个关键点处的状态以及

冷热流体的进出口状态参数，讨论了窄点位置并分析蒸发温度、冷凝温度、发生温度这三个因素分别对循环性能的影响。

根据软件模拟计算出的各个关键点的状态参数，对循环的关键部件冷凝器、蒸发器部位进行管壳式换热器设计。先计算出换热量，再根据换热量和初选传热系数进行传热面结构设计。然后根据折流板的各个参数进行换热器的壳程设计，估算了壳侧壁温，计算出壳侧换热系数。最后利用传热面积之比、壳侧壁温、管程阻力和壳程阻力进行校核，修改传热面结构，通过迭代使传热面积之比、壳侧壁温以及阻力均符合设计要求。

关键词：喷射式制冷 环戊烷 管壳式换热

A 100kW Ejector Refrigeration System with Cyclopentane

ABSTRACT

Huge amount of high grade energy is wasted in traditional compressing type of refrigeration system,also refregant that the system use usually brings a lot of damage to the ozone sphere,which will deepen the green house effect.so,it is quite important to find some low grade energy to do the job. Ejector refrigeration is one of the systems that use this kind of energy . this system has been widly used and is seemed as a promised system in the future.

Cyclopentane is set as the working medium and water is set as the heat source when the water is the cold source. During the research , MATLAB R2018b with REFPROP 9.1 is used to simulate the system’s data. The working medium’s whole status including entering and outgong flow’s status throughout the system will be caculated with the app. Also the position of the pinch points and the effect of evaporating temperature,causing temperature and freezing temperature to the whole system is also analysed through the reseatch.

The evaporimeter and the condenser will be designed with the significant data that caculated before. Fiest of all the amount of heat exchange will be caculated then the design will goes to heat passage face,depending on the data which is get before.after that,the shell side will be desigin with the data of baffles.depending on this data the temperature of the shell will be assumed,it helps figuring out the shell side heat conductivity. Finally all the data that is caculated will be run for several times to insure that all the request of the degisin are met.

Key Words: Ejector refrigeration; Cyclopentane; shell-and-tube exchang

目录

摘 要 I

ABSTRACT II

第一章 绪论 1

1.1研究背景及意义 1

1.2喷射式制冷国内外研究现状 1

1.2.1.喷射式制冷系统工质研究 1

1.2.2.喷射式制冷系统结构研究 2

1.2.3.喷射式制冷系统应用的研究 4

1.3研究内容 5

1.4本章小结 6

第二章 喷射式制冷模型分析 7

2.1工作原理 7

2.2循环模型的建立 8

2.2.1.已知参数 8

2.2.2.建立模型 8

2.2.3.窄点位置的判断 11

2.2.4.标准工况下参数 13

2.3循环性能分析 14

2.3.1.发生温度对循环性能的影响 14

2.3.2.蒸发温度对循环性能的影响 16

2.3.3.冷凝温度对循环性能的影响 18

2.4本章小结 21

第三章 管壳式换热器设计 22

3.1冷凝器部位换热器设计 22

3.1.1.设计思路 22

3.1.2.传热量、定性温度和初始参数 22

3.1.3.估算传热面积、设计传热面结构以及管程计算 23

3.1.4.壳程结构及壳程计算 26

3.1.5.传热面积校核、壁温校核及阻力校核 27

3.2蒸发器部位换热器设计 29

3.2.1.初始参数 29

3.2.2.管侧换热系数和壳侧换热系数 30

3.3本章小结 30

第四章 总结 31

参考文献 32

附录一 喷射式制冷循环热力计算程序 34

附录二 冷凝器段换热器设计计算程序 38

附录三 冷凝器段换热器设计计算程序 40

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