共查询到15条相似文献，搜索用时 171 毫秒
1.
《浙江大学学报(A卷英文版)》2020,(1)
目的:目前关于内冷型溶液除湿器的研究均基于特定的装置结构和流型,限制了其普遍应用。本文采用基于传热单元数的传热传质数学模型,通过数值模拟研究了各种流型、结构和流体参数的影响。创新点:1.提出一种新的除湿效率定义;2.引入?效率评价内冷型除湿器的性能;3.分析不同流型、结构和流体参数下除湿器除湿效率和?效率;4.研究结论不受特定装置和流体参数的限制,为内冷型除湿器的设计优化提供了建议。方法:1.建立内冷型除湿器的物理和数学模型;2.通过实验数据与模拟数据的对比,验证模型的正确性;3.建立除湿效率和?效率的数学模型;4.通过不同流型、结构和流体参数的模拟数据,分析其对除湿效率和?效率的影响。结论:1.本文提出了一种新的除湿效率定义,解决了内冷型除湿器在某些工况下除湿效率超出0～1范围的问题;溶液入口平衡含湿量根据入口溶液和冷却水的最低温度计算,并且新的除湿效率综合考虑了冷水的代价,可以更好地评价除湿器的除湿性能。2.对于内冷型除湿器,三种空气与溶液间流型的除湿效率和?效率总是逆流最好,叉流其次,顺流最差;溶液与冷水之间的流型对两种效率影响不大,I流型比Ⅱ流型提升5%左右。3.LiCl溶液的除湿效率高于CaCl2溶液,可以提高60%,但LiCl溶液的?效率低于CaCl2溶液,可降低16%。4.在设计内冷型除湿器时应采用较大的空气与溶液间传热单元数,并建议在其运行过程中使用浓度较高的溶液及入口温度较低的溶液和空气,以达到更高的除湿效率和?效率。 相似文献
2.
空气除湿与人们日常生活和生产活动密切相关。综述了冷却除湿、液体吸收除湿、固体吸附除湿和膜除湿技术在空调领域的应用,介绍了各种除湿方式的工作原理和类型,分析了各自特点及在应用中应当注意的问题,并对未来的除湿技术进行了展望。 相似文献
3.
提出一种新型的液体除湿系统——超声雾化液体除湿系统,该系统用超声雾化技术取代了传统塔式除湿过程中的填料,避免了由填料带来的溶液耗量大和阻力大的缺点.建立了数学模型来预测在理想条件下液体除湿过程的效率及耗液量.通过对比计算结果和传统塔式除湿的实验数据,发现后者的溶液耗量远大于理想情况下的耗量.另外,在提出的系统中除湿过程发生在通过超声作用产生的微小除湿剂液滴表面,等量的除湿剂能够产生更大的反应表面积;整个新系统中没有喷嘴和溶液泵,系统阻力和能耗相应降低.因此,该方法比塔式除湿方式更接近于理想情况. 相似文献
4.
除湿制冷用优良吸附剂的特性研究 总被引：6，自引：0，他引：6
对自制吸附剂 (DH 5 0 ,DH 70 ) ,硅胶和 13x的除湿制冷性能进行了实验研究 .测定了DH 5和DH 7吸附剂的吸附等温线 ;对DH 5 ,DH 7,硅胶和 13x用于除湿制冷过程的动态特性进行了研究 ;讨论了吸附量、空气湿度、再生温度和单位质量吸附剂的制冷量对固体除湿过程的影响 .结果表明 :DH 5和DH 7的除湿制冷性能明显优于常规吸附剂 (硅胶和 13x) .DH 5和DH 7吸附剂的最大平衡吸附量分别为 0 .72kg/kg和 0 .73kg/kg ;在 10 0℃条件下再生 ,DH 7吸附剂的除湿制冷量是硅胶的 2 .2倍 ,单位质量吸附剂的制冷量是硅胶 1.9倍 ;在较高再生温度(2 0 0～ 2 5 0℃ )下 ,DH 5吸附剂的除湿制冷量是 13x的 1.3倍 ,单位质量DH 7吸附剂的制冷功率是 13x的 2 .2倍 . 相似文献
5.
綦戎辉谭均 《实验室研究与探索》2023,(4):179-182
为了加强学生节能意识和科研创新能力，设计了基于质子交换膜的电解质膜除湿系统性能综合教学实验。学生通过自主设计外加电压的影响及性能衰减可逆特性分析等多个实验环节，发现了更高外加电压下膜电极具有更好的除湿性能，但衰减也更严重；性能衰减中约4/5为膜内含水量下降导致的可逆衰减，其余1/5为催化剂溶蚀或形成挥发性过渡氧化物导致的不可逆衰减。实验教学涉及文献调研、实验测试、数据分析等多个环节，加深了学生对化工原理、流体力学、传热传质等多学科知识的综合理解，对激发学生科研兴趣，培养创新思维和解决实际问题的能力十分有益。 相似文献
6.
介绍了一种应用于制冷空调领域的新型溶液除湿冷水机组,该系统可以由60～80℃的低品位热能驱动,如太阳能平板集热、余热废热等.对该系统建立了数学模型,理论分析了蒸发温度、再生温度、环境空气温湿度、封闭制冷循环和再生循环空气流量等参数对系统性能的影响.结果表明：系统在参考工况下制冷量为2.5kW,性能系数达0.37,制冷性能良好;再生温度和环境空气含湿量对系统制冷量和性能系数的影响较大,而环境空气温度的影响较小;同时,为了使得系统能够经济运行,再生空气流量不宜过大,而封闭制冷循环空气的流量也需要合理选择. 相似文献
7.
设计了一种热泵驱动的溴化锂溶液深度除湿机组,该机组适用于无回风可利用、低湿度需求的场合.机组的性能测试结果显示,当室外温度为28～31℃,含湿量为11～14g/kg时,机组的送风温度为1.6～2.6℃,含湿量为2.6～3.0g/kg,系统COP为1.8.测试时发现了一个造成冷热溶液混合损失的管路链接问题,并对其进行修改.然后,对修改后的新机组进行了性能测试,结果显示,在室外温度为25～32℃,含湿量为18～21g/kg时,机组的送风温度为3.2～4.0℃,含湿量为3.4～3.6g/kg,系统COP为2.8.最后,对机组建立数学模型,并将模拟结果与实测数据进行比较,结果表明管路改动使机组性能提升约20%. 相似文献
8.
针对常规空调和传统溶液空调在应用中存在的问题,提出一种基于地下水-太阳能工作的溶液除湿空调系统,分析了该系统工作原理及新回风空气处理方法,建立组成系统各部件热力学数学模型。以地处地下水资源丰富的洛阳某建筑为例,对新型系统与常规一次回风再热式空调系统进行能耗计算分析比较。结果显示,与常规一次回风再热式空调系统相比,该系统在采用电加热进行溶液再生时比常规系统节能54%;在采用太阳能集热器进行溶液再生时比常规系统节能69%。由于该系统节能效果显著,机组性能稳定可靠,在地热资源丰富的热湿地区有着广泛应用前景。 相似文献
9.
《西安文理学院学报》2020,(3)
井筒温度和传热分布对于井筒压力控制、泥浆性质、井壁稳定以及钻井工具特性有重要的影响.因此准确的预测井筒温度动态特性对于安全高效钻井有着重要意义.在前人研究基础上,基于井筒动态机理模型研究了井底和环空出口处钻井液温度随时间变化规律以及分析了当入口钻井液流速、比热等参数变化时,井底和环空出口钻井液温度变化趋势.研究表明在循环过程中,井底和环空出口温度逐步达到稳定值,当钻井液入口流量增大时,井底温度达到稳定值时间减小,井底温度几乎保持不变;降低钻井液入口比热容,井底温度达到稳定值时间增加,井底温度降低. 相似文献
10.
为了探索油气在冷凝回收过程中的冷凝规律,采用气液两相流模型描述了油气在竖直管内湍流流动时的冷凝过程.采用有效传质系数描述了油气组分的质量传递.模拟了油气在管内冷凝时的温度、管内压力、液膜厚度和Nusselt数的变化,得到了入口油气和管壁的温差、雷诺数对冷凝率和Nusselt数的影响.结果显示：增大入口雷诺数能显著增强传热和冷凝,但是增大入口油气和管壁的温差对冷凝率的影响较小;另外,还发现传质阻力对油气冷凝率有较大影响.此模型的计算结果与先前的实验数据能够很好地符合. 相似文献
11.
A mathematic model of two-phase flow and a physical model of two-dimensional (2D) vertical section for the plate-type structured packing Mellapak 250.Y were set up and verified. The models were used to study the influence of packing’s surface microstructure on the continuity of liquid film and the amount of liquid holdup. Simulation results show that the round corner shape and micro wavy structure are favorable in remaining the continuity of liquid film and increasing the amount of liquid holdup. The appropriate liquid flow rate was determined by investigating different liquid loadings to obtain an unbroken liquid film on the packing surface. The pressure difference between inlet and outlet for gas phase allowed gas and liquid to flow countercurrently in a 2D computational domain. The direction change of gas flow occurred near the phase interface area. 相似文献
12.
Surface wave dynamics of falling film on the surface of periodic rectangular wall under monochromatic-frequency flowrate forcing disturbances is studied via numerical simulation. Waveforms formed on the periodic rectangular wall are different from those on the flat plate. At low frequency, the perturbation introduced at the inlet first undergoes a steady flow region and then develops into solitary waves. When the frequency becomes higher, solitary waves disappear. Film deformations in the steady flow region and characteristics of solitary waves are studied as the film travels down. There are circulations at the depression of periodic wall which are dependent on the local film characteristics and geometry of the corrugation. Moreover, the flow rate and geometry of the corrugations can also affect the evolvement of the monochromatic perturbation. 相似文献
13.
介绍了一种自行研制的空调表冷器热工性能测试系统,该系统是通过对实验室现有空气调节处理过程实验台进行改造制得。在压缩机和节流阀之间装设套管式蒸发器,制得冷冻水,经水泵送入表冷器中,与空气进行换热后重新返回套管式蒸发器中。通过温控器实现表冷器入口冷冻水温度的控制,表冷器进出口冷冻水温通过布置热电偶进行测量,冷冻水流量通过转子流量计进行测量,利用原有干湿球温度计测量空气进出口干湿球温度,进而在不同工况下实现表冷器析湿系数、热交换效率、接触系数和换热量的测试。依据测试结果分析风量、风速、冷冻水流量对表冷器热工性能的影响。 相似文献
14.
The high temperature heat pump and desiccant wheel(HTHPDW) system can make full use of heat released from the condenser of heat pump for DW regeneration without additional heat. In this study, DW operation in the HTHPDW system was investigated experimentally, and the optimization analysis of HTHPDW system was carried out. The performance of DW had influence on the dehumidification(evaluated by dehumidification and regeneration effectiveness) and cooling load(evaluated by thermal and adiabatic effectiveness). The results show that the enthalpy increase occurred in all the experiments. Compared to the isosteric heat, heat accumulation in the desiccant and matrix material and heat leakage from regeneration side to process side have greater influence on the adiabatic effectiveness. Higher regeneration temperature leads to lower adiabatic effectiveness that increases more cooling load of the system. When the regeneration temperature is 63℃, the maximal dehumidification effectiveness is 35.4% and the satisfied adiabatic effectiveness is 88%, which contributes to the optimal balance between dehumidification and cooling. 相似文献
15.
A quasi 1D model of two-phase flow for a urea-selective catalytic reduction (SCR) system is developed which can calculate not only the generation of reducing agent but also the formation of deposits in the exhaust pipe. The gas phase flow is solved through Euler method, variables are stored on staggered grids, and the semi-implicit method for pressure-linked equation (SIMPLE) algorithm is applied to decouple the pressure and velocity. The liquid phase is treated in a Lagrangian way, which solves the equations of droplet motion, evaporation, thermolysis, and spray wall interaction. A combination of a direct decomposition model and a kinetic model is implemented to describe the different decomposition behaviors of urea in the droplet phase and wall film, respectively. A new 1D wall film model is proposed, and the equations of wall film motion, evaporation, thermolysis, and species transport are solved. The position, weight, and components of deposits can be simulated following implementation of the semi-detailed kinetic model. The simulation results show that a decrease in the exhaust temperature will increase the wall film region and the weight of deposits. Deposit components are highly dependent on temperature. The urea-water-solution (UWS) injection rate can affect the total mass of wall film and expand the film region, but it has little influence on deposit components. An increase in exhaust mass flow can decrease the total weight of deposits on the pipe wall because of the promotion of the mass and heat transfer process both in the droplets and wall film. 相似文献