【作者】 尹应德；

【导师】 朱冬生；

【作者基本信息】 华南理工大学 ， 化学工程， 2012， 博士

【摘要】 随着我国经济的高速发展，以及人们对高品质工作和生活的追求，能源相对短缺的问题日益严重。建筑能耗是整个国民经济能耗中的重要组成部分，而空调和制冷系统的能耗是建筑能耗中最主要的能耗之一。蒸发式冷凝制冷系统作为制冷系统中的一种方式，具有高效节能和节水的特点。但人们对它的研究尚不多见，相关的研究资料和数据也十分缺乏。基于以上原因，本文对蒸发式冷凝制冷系统进行了深入研究分析，主要研究内容如下：根据计算流体动力学(Computational Fluid Dynamics)中关于气-液两相流的处理方法，采用VOF(volume of fluid)多相流模型，建立了水平换热管外气-液两相流动和传热传质的计算模型，并通过数值模拟研究流体流动特性和传热传质现象。模拟结果表明：在气-液两相逆流传热过程中，潜热传热量所占气-液界面总传热量的比值在90%以上；气-液两相逆流时，潜热传热量所占气-液界面总传热量的比值比气-液两相顺流时高；在气-液相界面处的换热形式是以水蒸发传质引起的潜热换热为主、以温差引起的显热传热为辅，逆流比顺流更有利于传热。详细介绍了蒸发式冷凝制冷系统的实验装置，该实验装置主要为蒸发式冷凝制冷系统模型的验证提供实验数据，并为其性能优化研究提供实验平台。在实验中，主要测试了冷却水喷淋密度、室外空气干（湿）球温度、空气流速、入口空气相对湿度等参数对蒸发式冷凝制冷系统的强化传热性能和制冷性能的影响；在接近名义工况的条件下，测试得到本实验系统的能效比(Energy Efficiency Ratio)为3.78，远高于国家相关规范中的蒸发式冷却制冷（系统）机组的制冷性能系数（国标要求不低于2.4）的数值。采用效率法建立了涡旋式压缩机的稳态模型；采用分布参数法建立了蒸发器和蒸发式冷凝器的稳态分布参数模型；采用顺序模块法，建立了蒸发式冷凝制冷系统整体模型。通过对整体模型的模拟值与实验值比较表明：系统制冷量的模拟值误差10%以内，散热量的模拟值误差10%以内，能效比(EER)的模拟值误差10%左右；由此可见，本蒸发式冷凝制冷系统模型的精度较高，能准确地模拟系统的热力性能。在以上研究的基础上，结合模拟和实验的手段，对蒸发式冷凝制冷系统的压缩机、制冷剂、蒸发器的选择及蒸发式冷凝器的强化传热进行研究分析。得到的结论为：(1)R134a适用于蒸发式冷凝制冷系统；作为R22的替代制冷剂， R-407C适合于使用干式蒸发器的蒸发式冷凝制冷系统；R-410A适合于使用满液式蒸发器的全新设计的蒸发式冷凝制冷系统。(2)采用满液式蒸发器的系统能效比(EER)（制冷剂为R22）比采用干式蒸发器约高8.6%-14%左右。(3)在一定的实验范围内，空气湿球温度对蒸发式冷凝制冷系统性能的影响最大，其次为空气流速，再次为空气相对湿度，最次为冷却水喷淋密度；在相同的实验条件下，蒸发式冷凝器的换热盘管为圆管、椭圆管以及扭曲管型的蒸发式冷凝制冷系统能效比依次增大，且增幅显著。采用Visual Basic语言开发了一款蒸发式冷凝制冷机组的快速选型软件，该软件可以实现以下功能：(1)根据建筑类型、建筑面积、预测的EER值，快速选出蒸发式冷凝制冷机组的主要设计参数，为生产厂家提供具体产品设计要求依据。(2)已知建筑物的详细制冷量需求，快速选出蒸发式冷凝制冷机组的主要设计参数，校核生产厂家生产的具体产品是否满足实际要求。介绍了蒸发式冷凝制冷系统节能改造示范工程的具体实施情况，其现场测试结果表明：较之原有的水冷式制冷机组冷源系统，蒸发式冷凝制冷机组冷源系统的节能率为16.3%，节水率为39.7%。本文的研究结果为蒸发式冷凝制冷系统在建筑舒适性空调领域的应用提供了可靠的理论和实验数据，具有重要的参考价值。更多还原

【Abstract】 With China’s rapid economic development, as well as the persuit of the high-qualitywork and life, the relative shortage of energy is becoming increasingly serious. Buildingenergy consumption is an important component part in the national economy energyconsumption, and air conditioning and refrigeration system’s energy consumption is one ofthe main energy consumption of building energy consumption. As one of the refrigerationsystems, the evaporative condensed refrigeration system has the features of high efficiencyenergy-conservation and water-conservation. But the research is still rare, related researchinformation and data are very lack. Based on the above reasons, the evaporative condensedrefrigeration system had been in-depth research and analysis in the issue, and the mainresearch contents are as follows:Based on CFD (computational fluid dynamics) on gas-liquid two-phase approach, usingthe VOF(volume of fluid) multiphase flow model, and the gas-liquid two-phase flow andheat and mass transfer computational model outside horizontal heat exchanged tube wasestablished, the fluid flow characteristics and heat and mass transfer phenomena wassimulated by numerical simulation. Simulation results show that: in the gas-liquid two-phaseprocess of counter current flow, the heat transfer of latent heat percentage ratio is more than90%in the total heat transfer rate on gas-liquid interface, and the latent heat transfer rate ofgas-liquid two-phase counter current flow is higher than that of the gas-liquid two-phaseconcurrent flow. The form of heat and mass transfer in the gas-liquid interface is caused bywater evaporation’s latent heat exchange based, supplemented by sensible heat exchange, heatexchange is more conducive to counter current flow than that of concurrent flow.The evaporative condensed refrigeration system’s experimental device was introduceddetailedly. The experimental device mainly was used to provide experimental data for thevalidation of evaporative condensed refrigeration system models, and also used to provide theexperimental research platform for evaporative condensed refrigeration system performanceoptimization. the cooling water spray density, outdoor air dry (wet) bulb temperature, air flow,intake air relative humidity etc key parameters were Tested for the enhanced heat transferperformance and refrigeration performance of the evaporative condensed refrigeration system,and tested to get the energy efficiency of the experimental system energy efficieny ratio(EER) of3.78nearly in the nominal operation conditions, it is much higher than the relevantnational standards for evaporative condensed (system) chiller’s energy efficieny ratio (EER) (GB requirement of not less than2.4) values.The steady-state model of scroll compressors was established by the usage of efficientmethod, the steady-state distribution parameters’ models of the evaporator and evaporativecondenser were established by the usage of the distribution parameters method, theevaporative condensed refrigeration system model was established by the Usage of sequentialmodular approach. the comparison of the system model through simulation and experimentalvalues shows that: the system cooled capacity simulation error is less than10%, the systemcondensed heat simulation error is within10%error, and energy efficiency ratio (EER)simulation error is about10%; thus, the result shows the high accuracy of the model of theevaporative condenser refrigeration system, and it can accurately simulate the thermalperformance of the system.Based on the above study, combined simulation and experimental means, the choice ofevaporative condensed refrigeration system’s compressor, refrigerant, evaporator andenhanced heat transfer research of evaporative condenser was analyzed. The followingconclusions are obtained:(1) R134a is adapted to evaporative condensed refrigeration system;as an alternative to R22refrigerant, R-407C is suitable for dry-type evaporator’s evaporativecondensed refrigeration system; R-410A is suitable for flooded evaporator design ofevaporative condensed refrigeration system.(2) The energy efficiency ratio (EER) of floodedevaporator’s chiller system (R22refrigerant is used) is higher than that of the dry-typeevaporator for about8.6%-14%.(3) in a certain experimental range, for the effect to theevaporative condensed refrigeration system performance, the gradation from much more toless is air wet bulb temperature, air velocity, relative humidity of the air, the cooling waterspray density orderly; in the same experimental conditions, the energy efficiency ofevaporative condensed refrigeration system with which evaporative condenser’s heatexchange coil is tube, oval tube and twisted respectively in turn increases, and the increase issignificantly.The rapid selection software for evaporative condensed plant was developed by usingVisual Basic language, it can achieve the following functions:(1) according to building type,building size, predicted EER values, the main design parameters of an evaporativecondensed refrigeration plant can be selected rapidly for the manufacturer to provide specificdesign requirements basis.(2) When the detailed cooled capacity for building requirements isconfirmed, the main design parameters of an evaporative condensed refrigeration plant can beselected rapidly to check the manufacturer’s specific product, which is produced to meet theactual requirement or not. Moreover, the actual condition of an energy-conservation demonstration project used evaporative condensed refrigeration plant was introduced. Thefield-tested results showed that: compared to the original water-cooled refrigeration plantresource system, the evaporative condensd refrigeration plant resource system’senergy-conservation rate was16.3%, and its energy-conservation rate was39.7%.The results of this issue can provide reliable theoretical and experimental data for theevaporative condensed refrigeration system’s applications in the field of comforted airconditioning in buildings, and have important reference values.更多还原