【作者】 袁秋霞；

【导师】 马一太；

【作者基本信息】 天津大学 ， 工程热物理， 2012， 博士

【摘要】 在节能减排的背景下，本文以热泵热水机能效标准和CO2跨临界水水热泵循环为研究对象开展了研究。本文对热力学完善度进行理论研究。热力学完善度即热力学第二定律效率，它反映制冷热泵设备的效率偏离理想状态下效率的程度，其意义在于，它可用于评价同类制冷热泵设备变工况下的能效水平，还可用于比较不同类制冷热泵设备的能效水平。本文对我国市场上热泵热水机的能效现状进行调研，结果显示空气源普通型热泵热水机COPh值最低值为2.93；水源热泵热水机COPh值最低值为3.55。以样本调研数据为基础，结合热力学完善度理论分析，提出热泵热水机的3级能效标准的建议值，例如普通型空气源热泵热水机的COPh从3级、2级到1级分别3.7、4.0和4.3。最后提出空气源热泵热水机经济运行评价指标——全年综合性能系数（ACOP）的计算方法。在原有基础上设计并建立了配备更好换热效果的套管式气体冷却器和满液式蒸发器的CO2水水热泵实验台。在该实验台上对气体冷却器进行了可视化试验研究。当冷却水入口水温一定，试验高压逐渐升高时，对气体冷却器中后部B和后部C试验段的流动状态进行可视化观察，结果表明：试验段B、C的状态均依次经历了透明、暗白、亮白、暗白、透明这五个状态，其中三个状态中暗白、亮白、暗白的对比压力值范围为0.94～1.02，其流体状态在接近临界区的两相区或临界区。试验测量结果和对试验段B的可视化研究：存在一个最优高压压力使得试验段B至试验段C达到最大换热量。本文介绍了新研制的CO2满液式蒸发器，并对采用光管管束和强化管管束进行换热对比试验研究。试验结果表明，在相同热流密度下，光管管束中各管排的局部沸腾换热系数随管排高度的升高而增大；而在强化管管束中各管排的局部沸腾换热系数随管排高度的升高反而降低。根据换热试验数据，推导了采用强化管管束的CO2满液式蒸发器的各管排局部沸腾换热关联式，预测数据与试验数据对比有±15%以内的误差。采用高速摄影可视化手段对光管管束的CO2满液式蒸发器的沸腾现象进行试验观察，近似认为CO2汽泡的生长、脱离、上升和破灭的全过程的时间约172ms，其上升速度为0.3m/s～0.45m/s，汽泡脱离直径0.4mm～0.8mm。更多还原

【Abstract】 On the background of energy saving and emission reduction, the research onenergy-efficiency standards for heat pump water heater and CO₂transcriticalwater-water heat pump cycle were carried out in this dissertation.Thermodynamic perfectibility was theoretically analyzed in this dissertation.Thermodynamic perfectibility is the Second Law Efficiency of Thermodynamics andit reflects the departure degree between the practical efficiency of refrigeration andheat pump products and the ideal efficiency. The significance of thermodynamicperfectibility is that it can evaluate not only the energy-efficiency of the same type ofthe refrigeration and heat pump products in variable condition but also theenergy-efficiency of the different types of the refrigeration and heat pumpproducts.The status of energy efficiency of heat hump water heaters in Chinesemarket was surveyed，and the statistical results showed that the lowest COPhof thecommon air-source heat pump water heater and water-source heat pump water heaterare2.93and3.55,respectively. On the basis of the statistical data and the theoreticalanalysis of thermodynamic perfectibility, the suggested values of energy efficiencygrades standard on heat pump water heater were put forward. For example, thesuggested COPhvalues of the common air-source heat pump water heater from3grade to1grade respectively are3.7,4.0and4.3.The annual coefficient ofperformance （ACOP） was brought forward as the evaluation index of economicoperation for air-source heat pump water heater，and the caculation method wasintruoduced.Based on the old test table, a CO₂water-water heat pump system using a betterdouble pipe gas cooler and flooded evaporator was established. The visualizationexperiment on the gas cooler was done on this system. By visual observation on theflow state of the postmedian experimental section B and rear experimental section Cof the gas cooler, the flow states of experimental sections B and C experiencedsuccessively five states: transparent,dark white,bright white,darkwhite,transparent,while the working high pressure increases gradually and the coolingwater inlet temperature keeps constant. In the cooling water temperature15℃～24℃,the reduced pressure of the experimental section B in the dark white,bright white,dark white states is0.94～1.02, and these states are under two phase region near criticalarea or critical area.The experimental results and the visual observation on theexperimental sections B showed that the heat transfer rate between experimentalsections B and C reached the maximum under the optimum high pressure.A newly developed CO₂flooded evaporator was introduced in this dissertation.The tube bundle of the flooded evaporator adopted smooth tubes or enhanced tubes.The comparison test on the flooded evaporator using smooth tubes or enhanced tubeswas carried out in this dissertation. The experimental results showed that the localboiling heat transfer coefficient of the smooth tube arrays increased with the increaseof the vertical height of tube arrays at the same heat flux. Whereas the local boilingheat transfer coefficient of the enhanced tube arrays increased with the decrease of thevertical height of tube arrays. In according to the experimental data, the local boilingheat transfer correlation equation of the enhanced tube arrays was deduced, and thepredicted data agreeed with the experimental data within about±15%.The boiling heat transfer of the flooded evaporator using smooth tube bundle wasobserved by the high speed photography. The visualization results showed that thetotal progress of growth, departure, rise and break of CO₂bubble lasts about172ms;the rise speed of bubble is0.3m/s～0.45m/s and the bubble departure diameter is0.4mm～0.8mm.更多还原