填料塔除湿器性能影响因素的实验研究外文文献的翻译、中英文翻译、外文翻译

2014届毕业设计说明书
外文文献
院、部：机械工程学院
学生姓名：平天水
指导教师：邹芝芳职称副教授
专业：机械设计制造及其自动化班级：机本1001班
完成时间：2014年5月
The performance of packed tower dehumidifier Experimental study on the impact of factors
Abstract: The structures of lithium chloride solution as liquid desiccant dehumidification air-conditioning agents experimental system, through experiments, analysis of a packed tower dehumidifier in the process of the operating parameters of the desiccant air-conditioning system performance, the import volume of air moisture imports solution desiccant temperature and concentration on a greater impact in the desiccant in tower design should pay due attention to.
Key words: Liquid Desiccant Air Conditioning Packed tower dehumidifier Experimental study Performance Analysis
1 Introduction
Liquid desiccant air conditioning system with clean, energy-saving, easy operation and low-grade energy, environmental protection and good performance, it is suitable for solar energy and industrial waste heat as renewable heat source, with great energy saving potential and environmental effects [6]. Many experts and scholars at home and abroad for liquid desiccant air conditioning for a large number of studies. In liquid desiccant air conditioning system, the dehumidifier is the core component of the system, dehumidifier the structure and properties of a direct bearing on the merits of the success or failure of the air-conditioning system. How to design a dehumidifier, dehumidifier enhanced heat and mass transfer in the process, reduce the flow resistance is to be processed, such as air through the dehumidific-
-ation process of air-conditioning required to achieve the key.
The desiccant dehumidifier is a complex process of heat and mass transfer process. Its basic principles, is the driving force of mass transfer of water vapor in air pressure and moisture absorption of the salt solution the surface of the water vapor pressure difference, when the partial pressure of water vapor the air is higher than the surface of salt solution of the water vapor pressure, to achieve water steam from gas to liquid transfer process, gas-liquid two-phase long enough exposure time, the two-phase mass transfer process of achieving this balance, the migration of water vapor in the air and get out of dry desiccant to absorb moisture and diluted solution. After absorption by the dilute solution after heating, into the regenerator, when the salt solution is higher than the vapor pressure of water vapor the air pressure, water vapor began to transfer from liquid to gas, to achieve the regeneration of the desiccant solution. Usually do not have a high heat source heating, solar or industrial waste heat can make use of. Renewable after re-sent back to the strong solution for desiccant dehumidifiers, so that the dehumidification and regeneration of the formation of a continuous cycle.
2 Principle and device test
Packed tower dehumidifier for research, including theoretical research and experimental study of two aspects, first of all, theoretical studies based on theoretical modeling of energy balance and mass balance equations for the desiccant dehumidifier in the process of theoretical research and analysis, the establishment of regular type packing of the packed tower dehumidifier heat and mass transfer model to study the process of tower desiccant
dehumidification performance of the various parameters on impact. Packed tower dehumidifier in the theoretical research that there are many research results, this paper will be re - points on the desiccant air conditioning system in the packed tower dehumidifier Experimental research, focusing on the process reveals the desiccant solution in the air and the import and export of temperature, humidity, flow rate changes in parameters such as the impact of the desiccant system and their role in the law to experiment to find liquid desiccant dehumidification air conditioning system design parameters and the best operating conditions.
2.1 Data Acquisition and Processing
Experimental study of liquid desiccant in the process, the use of copper - constantan thermocouple to measure air and solution temperature, air relative humidity and absolute humidity, measured by the dry and wet-bulb temperature value, calculated through the development of computer programs be; the use of Y-Bi Trust and micro-pressure air flow rate measured; the use of glass LZB-40 rotameter was at a flow rate of solution; least square method with the solution concentration and the corresponding relationship between the density by measuring the density of the solution, find the corresponding solution concentration. Parameter values through all of the ADAM-4018 +-based acquisition module with the
ADAM-4520 converter module to the measured signal analog-digital conversion, by the
RS-232 serial transmission to the computer through the preparation of data collection procedures for VB access to real-time data.
3 Experimental Results and Analysis
The impact of packed tower desiccant dehumidifier performance of a number of factors, this experiment was to determine the parameters of the theoretical research institute within the effective range of [2], for air and solution temperature, flow rate and solution concentration on the impact of desiccant. Imports of selected parameters of the desiccant tower is: a. air import wind: the wind speed range 1.0 ~ 3.0m / s, each experiment in order to speed 0.4m / s increments; b. solution flow: the flow changes in the scope of 1.68 ~ 1.68 × 5 kg/m2 • s, for each experiment to 1.68 kg/m2 • s increments; c. import air dry-bulb temperature: air temperature range 26 ~ 42 ℃, for each experiment to control the increase of 2 ℃around; d. air absolute imports moisture content: the scope of the air absolute moisture content 12 ~
24g/kgDA, each experiment to control the increasing 2g/kgDA around; e. solution temperature: 25 ~ 40 ℃in the framework of control for each experiment in order to increase about 1 ℃. Experiment to maintain a ~ e, respectively, in a certain parameter increased from low to high, while the other parameters remain unchanged. Adjust each parameter, until a stable condition, and then collect and record data, analysis, after finishing a group of dehumidifiers come to the entrance of the parameters of the impact of the volume of air dehumidification curves.
Figure 2 ~ Figure 4 describe the state of the parameters on the solution of import and export parameters and dehumidification of air volume change. Response to different concentrations of the solution, the solution and the air change the import parameters, as well as their exports dehumidification efficiency parameter changes affect the trend.
3.1 solution flow of imports to exports of air moisture, temperature, solution temperature and dehumidification efficiency of export of the impact of a moisture content of air changes in exports b air outlet temperature
c solution outlet temperature changes
d changes in th
e efficiency o
f d Dehumidifier Figure
2 with the parameters of the export status of the changes in the flow of imports of solution
Figure 2 (a), (b) and (c) reflect the moisture content of air export, air and solution outlet temperature as the solution to reduce the increase in traffic. Increase the flow of solution between the gas-liquid heat and mass transfer to more fully carried out, but compared with the unit mass of solution flow, the liquid absorbed by the sensible heat and latent heat are reduced, thus the import export solution temperature solution with the increase in traffic downward trend. The lower the solution temperature, solution the smaller the partial pressure of water vapor, the greater the driving force of mass transfer, mass transfer coefficient will be higher. Therefore, when the solution flow of heat and mass transfer have been strengthened; solution flow in small, relatively steep curve, with the increase of solution flow, the trend tends to smooth curves. Show that the reduced flow in the solution, the wettability of the filler is not enough to increase the solution flow, packed column wetting rate of increase in effective area to increase heat and mass transfer, heat and mass transfer to enhance rapid, with the increase of solution flow, heat and mass transfer area has become stable, heat and mass transfer process is stabilized, the performance curves tend to flat. Figure 2 (a), (b) below, the air moisture content with the solution of the export flows downward trend in the increase of temperature and concentration by the solution of the constraints, the final vapor pressure and solution equilibrium exports; and air temperature decreased the level of exports With the increase of solution tends to flow gently, when the solution flow to reach 4 × 1.68kg/m2 • s more, the concentration of the solution has little effect caused by the change; Figure 2 (c), (d) respond to the solution outlet temperature , desiccant solution flow with the changes in the efficiency of the experimental data, when the solution flow to reach 3 × 1.68kg/m2 • s more, the solution outlet temperature and dehumidification efficiency tends to a certain value.
3.2 volume of imports of air moisture and air to the solution of the impact of export parameters
Figure 3 describes the dry-bulb air temperature for 34 ℃, the solution flow 5.04kg/m2 • s, the solution tempe rature is 30 ℃, the solution concentration of 30%, 35%, 40%, the solution and air import export parameters with air absolute moisture content changes.
b air outlet temperature
c solution outlet temperature changes Figure 3 with the parameters of the export status of the air moisture content change in import Figure 3 (a) an
d (b) show that th
e imports o
f air absolute moisture content changes in air moisture content on the export of almost no effect; air and solution with the air outlet temperature of the increase in imports while absolute humidity increased, the experimental results in air outlet the maximum and minimum temperature difference between the 2.3% solution in the flow, we can ensure that the air in the entire range of moisture content, heat and mass transfer are more fully carried out. (C) and (d) gives the solution, respectively, temperature and dehumidification efficiency of exports with imports of the increase in absolute humidity of air and increasin
g trend. The greater the amount of desiccant to remove the water vapor emitted by the latent heat is also more and more, so the corresponding solution temperature increased, ranging from a maximum of 6 ℃, the average of the tower mass transfer coefficient has little effect on changes in moisture content, therefore does not export obvious.
3.3 solution and air temperature on the solution of the impact of export parameters
a moisture content of air changes in exports
b air outlet temperature
c solution outlet temperature changes
d changes in th
e volume o
f d Dehumidifier Figure 4 with the state parameters of the export import solution temperature
From Figure 4 that the air outlet moisture content, temperature of the experimental data with the solution temperature of imports increased significantly, which means that with the increase in solution temperature, the water vapor partial pressure increased, the driving force for mass transfer reduced , mass transfer coefficient decreased. Imports of high-temperature solution to a certain value, the solution efficiency of the dehumidifier gradually become smaller, until zero. At the same time, the solution to absorb the latent heat of condensation of water vapor to reduce the solution temperature dehumidifier and out of line. Air outlet temperature is mainly associated with the solution temperature, the trend of imports followed by the solution temperature. When the solution temperature is 25 ℃, air dehumidification rate above 60%, when the solution temperature rose to 40 ℃, the rate of dehumidification of air tends to zero, when the desiccant is no longer, if the temperature further increased , that is, into a tower dehumidifier regeneration tower.
4 Discussion and conclusions
In the packed tower dehumidifier selected and the scope of gas-liquid flow on the basis of the liquid desiccant air conditioning system of the packed tower dehumidifier for the dehumidification process of the experiment was studied in the dehumidification process parameters on the export of the import parameters the impact of specific points as follows:
a) determine the solution concentration, the solution temperature is to determine the export tower desiccant air moisture an important factor, the actual application, select the appropriate solution temperature can be realized by wet air heating, cooling dehumidification air handling different process. b) When the wind speed in the 1.2 ~ 2.2 m / s range, and solution flow as compared to the effects of desiccant, desiccant air velocity on impact is much smaller, air outlet moisture content is almost no change in wind speed, the wind speed less impact.c) discussed in this paper the framework of gas-liquid flow, when the liquid-gas ratio (mass flow ratio) greater than 2.6, the air outlet moisture content and air outlet temperature with the increase of solution flow is almost no change can be considered the best in the
liquid-gas ratio of about 2.6.
Through the experiment, was to change the desiccant tower gas, liquid import export value for the parameter values of the impact of changes in trend. State parameters such as air speed of imports, imports of dry-bulb air temperature, air moisture content, such as import export air have little impact on the state parameters, and the solution temperature, liquid-gas ratio and desiccant solution concentration on the impact. Desiccant tower so that the export of air temperature, moisture content of the desiccant solution-dependent parameters are larger in the Dehumidification tower should pay due attention to design
填料塔除湿器性能影响因素的实验研究
摘要：搭建以氯化锂溶液为除湿剂的液体除湿空调实验系统，通过实验，分析研究了填料塔在除湿过程中的运行参数对空调系统除湿性能的影响，进口空气含湿量、进口溶液温度和浓度对除湿影响较大，在除湿塔设计中必须加以重视。

关键词：液体除湿空调填料塔除湿器实验研究性能分析
1 引言
液体除湿空调系统具有清洁、节能、易操作和所需能源品位低、环保性能好等优点，很适合以太阳能及工业废热作为再生热源，具有较大的节能潜力和环保效应[6]。

国内外许多专家学者对液体除湿空调进行了大量的研究。

在液体除湿空调系统中，除湿器是系统的核心部件，除湿器的结构与性能的优劣直接关系到空调系统的成败。

如何设计除湿器，强化除湿器中的传热传质过程，减少流动过程的阻力，是使被处理的空气通过除湿等过程达到空气调节要求的关键。

除湿器内的除湿过程是一个复杂的传热与传质过程。

其基本原理为，传质的推动力是空气中水蒸气的分压与吸湿的盐溶液表面的水蒸气压之差，当空气的水蒸气分压高于盐溶液表面的水蒸气压，实现水蒸气由气相向液相的传递过程，气液两相接触的时间足够长，则两相的传质过程达到平衡，空气中的水蒸气迁移出来而得到干燥，除湿溶液吸收水分而被稀释。

吸湿后的稀溶液经加热升温后，送入再生器，此时盐溶液的水蒸气压高于空气的水蒸气分压，水蒸气开始由液相向气相传递，实现了除湿溶液的再生。

通常加热热源不用很高，太阳能或工业废热都能利用。

再生后的浓溶液重新送回除湿器进行除湿，这样就形成了除湿和再生的连续循环过程。

2 试验原理与装置
对填料塔除湿器的研究包括理论研究和实验研究两个方面，理论研究首先基于理论建模的能量平衡和质量平衡方程，对除湿器内的除湿过程进行理论研究和分析，建立规整型填料的填料塔除湿器的传热传质模型，研究塔器除湿过程中各参数对除湿性能的影响。

在填料塔除湿器的理论研究方面已有很多研究成果，因此本文将重点集中在除湿空调系统中的填料塔除湿器的实验研究，着重揭示除湿过程中空气和溶液的进出口温度、湿度、流速等参数的变化对除湿系统的影响因素及其作用规律，以实验的方式寻求液体除湿空调系统中除湿器的设计参数和最佳运行工况。

2.1 数据采集与处理
在液体除湿实验研究的过程中，采用铜－康铜热电偶来测定空气和溶液的温度，空气的相对湿度和绝对湿度，由测得的干、湿球温度值，通过编制计算机程序计算得到；采用Y型毕托管和微压差计测定空气流速；采用LZB－40型玻璃转子流量计获得溶液的流速；用最小二乘法拟合出溶液浓度和对应密度之间的关系式，通过测出溶液的密度，查找该溶液对应的质量浓度。

所有的参数值通过ADAM
－4018+型采集模块与ADAM－4520型转换模块将测得的信号进行模数转换，经RS-232串口传输到计算机，通过VB编制数据采集程序获得实时数据。

3 实验结果及其分析
影响填料塔除湿器除湿性能的因素很多，本实验是在理论研究所确定的参数有效范围内[2]，针对空气和溶液的温度、流速和溶液的浓度对除湿的影响进行。

选定的除湿塔进口参数是：a.空气进口风速：风速变化范围1.0～3.0m/s，每次实验风速以0.4m/s递增；b.溶液流量：流量变化范围1.68~1.68×5 kg/m2·s，每次实验以1.68 kg/m·s递增；c.进口空气干球温度：℃，每次实验控制以2℃左右递增；d.
验控制以2g/kgDAe.左右递增。

实验中分别保持a~e中的某一项参数从低到高递增，而其他参数保持不变。

每次调整参数，等到工况稳定后，再采集和记录数据，分析整理后得出一组除湿器入口参数对空气除湿量的影响曲线。

图2～图4分别描述了各进口状态参数对溶液和空气出口参数及除湿量的变化影响。

反应不同的溶液浓度下，溶液与空气的进口参数变化对其出口参数以及除湿效率影响的变化趋势。

3.1 进口溶液流量对出口空气含湿量、温度、溶液出口温度和除湿效率的影响
空气出口含湿量的变化 b 空气出口温度的变化
c溶液出口温度的变化 d 除湿效率的变化
图2 各出口状态参数随进口溶液流量的变化
图2中的（a）、（b）和（c）反映空气出口含湿量、空气和溶液出口温度随着溶液流量的增加而降低。

溶液流量的增加使气液间的传热传质进行地更加充分，但相对于单位质量的溶液流量，液体所吸收的显热和潜热均在减小，因而出口溶液温度随进口溶液流量的增加呈下降趋势。

而溶液温度越低，溶液的水蒸气分压力越小，传质的推动力越大，传质系数也就越高。

因此，溶液流量大时传热传质得到了加强；在溶液流量较小时，曲线变化比较陡，随着溶液流量的增加，曲线趋势趋于平缓。

表明在溶液流量减小时，填料的润湿不够，溶液流量增加，填料塔润湿率增加，有效传热传质面积增加，传热传质增强较快，随溶液流量的增加，传热传质面积趋于稳定，传热传质过程也趋于稳定，性能曲线趋于平缓。

图2（a）、（b）所示，空气出口含湿量随溶液流量的增加而下降的趋势受到溶液温度和浓度的限制，最终与溶液出口的蒸汽压相平衡；而出口空气温度下降程度随着溶液流量的增加而趋于平缓，当溶液流量达到4×1.68kg/m2·s以上，由溶液的浓度变化引起的影响很小；图2（c）、（d）反应了溶液出口温度、除湿效率随溶液流量变化的实验值，当溶液流量达到3×1.68kg/m·s以上，溶液出口温度和除湿效率也趋于一定值。

3.2 进口空气含湿量对溶液和空气出口参数的影响
图3描述了在空气温度干球为34℃，溶液流量为5.04kg/m2·s，溶液温度为30℃，溶液浓度为30％、35%、40％时，溶液和空气出口参数随进口空气绝对含湿量的变化。

a 空气出口含湿量的变化
b 空气出口温度的变化
c 溶液出口温度的变化
d 除湿效率的变化
图3 各出口状态参数随进口空气含湿量变化
图3（a）和（b）表明进口空气绝对含湿量的变化，对出口空气含湿量几乎没有影响；空气和溶液出口温度随空气进口绝对湿度的增加而升高，实验结果中空气出口温度的最大值和最小值之间的差值为2.3％，说明在该溶液流量下，可以保证在整个空气含湿量范围内，传热传质进行得都较充分。

（c）和（d）分别给出了溶液出口温度和除湿效率随进口空气绝对湿度的增加而加大的趋势。

除湿量越大，除去的水蒸汽所放出的潜热也越多，因此溶液温度相应升高，幅度最高不超过6℃，对塔内平均传质系数影响不大，因此出口含湿量变化不明显。

3.3 溶液温度对溶液和空气出口参数的影响
c 溶液出口温度的变化
d 除湿量的变化
图4 各出口状态参数随溶液进口温度的变化
由图4得知，空气出口含湿量、温度的实验值随溶液进口温度的升高而明显上升，这表示随着溶液温度的上升，其水蒸气分压力升高，传质的推动力减弱，传质系数随之降低。

溶液进口温度高到一定值时，溶液的除湿效率逐渐变小，直至为零。

同时，溶液吸收的水蒸气凝结潜热减少，溶液进出除湿器的温度趋于一致。

空气的出口温度主要也是与溶液温度相关，趋势紧随溶液的进口温度的变化。

当溶液温度为25℃时，空气的除湿率在60%以上，当溶液温度上升到40℃时，对空气的除湿率趋于零，此时已不能再除湿，倘若温度再升高，除湿塔即转变为再生塔。

4 讨论与结论
在选定填料塔除湿器及气液流量范围的基础上，对液体除湿空调系统中的填料塔除湿器的除湿过程进行了实验研究，考察了除湿过程中进口参数对出口参数的影响，具体分述如下：
a) 溶液浓度确定后，溶液温度是决定除湿塔出口空气含湿量的重要因素，实际应用时，选择合适的溶液温度，可实现对空气的升温减湿、降温减湿等不同的空气处理过程。

b)当风速在1.2 ~2.2 m/s范围，与溶液流量的对除湿的影响相比，空气风速对除湿的影响要小得多，空气出口含湿量随风速几乎无变化，受风速的影响较小。

c) 在本文所讨论的气液流量范围内，当液气比（质量流量比）大于2.6后，空气出口含湿量和空气出口温度随溶液流量的增加几乎不再变化，可以认为最佳的液气比值在2.6左右。

通过实验，获得了改变除湿塔气、液进口参数值对各出口参数值变化的影响趋势。

空气进口状态参数例如风速、空气进口干球温度、空气进口含湿量等对空气出口状态参数的影响甚微，而溶液温度、液气比和溶液浓度则对除湿影响较大。

因此得知除湿塔的出口空气温度、含湿量对除湿溶液的参数有较大的依赖性，在除湿塔设计时必须加以重视。