CAJ | 학술논문

为分析微热管阵列平板太阳能集热器的热性能，该文建立了集热器的CFD模型，对其进行数值模拟，将模拟结果与试验结果进行对比，验证了模型的可靠性。采用该CFD模型对集热器保温层厚度进行优化，结果表明，当实心保温层导热系数分别为0.02、0.03、0.04、0.05 W/(m·K)时，优化的实心保温层厚度分别为4.5、5.0、5.5、5.5 cm。合理设计的中空保温层（空气层与实心保温层相结合的保温层形式）集热器能够达到与实心保温层集热器相当的保温隔热效果，同时可使集热器保温层成本及质量降低25%～50%。最后，该文给出了保温层总厚度分别为4、5、6 cm时的中空保温层厚度优化结果，为该类集热器保温层的设计提供了理论依据。
위분석미열관진렬평판태양능집열기적열성능，해문건립료집열기적CFD모형，대기진행수치모의，장모의결과여시험결과진행대비，험증료모형적가고성。채용해CFD모형대집열기보온층후도진행우화，결과표명，당실심보온층도열계수분별위0.02、0.03、0.04、0.05 W/(m·K)시，우화적실심보온층후도분별위4.5、5.0、5.5、5.5 cm。합리설계적중공보온층（공기층여실심보온층상결합적보온층형식）집열기능구체도여실심보온층집열기상당적보온격열효과，동시가사집열기보온층성본급질량강저25%～50%。최후，해문급출료보온층총후도분별위4、5、6 cm시적중공보온층후도우화결과，위해류집열기보온층적설계제공료이론의거。
In this paper, a three-dimensional CFD numerical model of heat transfer and fluid flow was developed to simulate the thermal performance of the novel flat plate solar collector based on a micro heat pipe array to provide a theoretical basis for the structure improvement and optimization of the collector. The simulation of the novel collector with water flow included the CFD modeling of solar irradiation and the modes of mixed convection and radiation heat transfer between the absorber plate and glass cover, as well as the heat transfer in the circulating water inside the heat exchanger and conduction of the insulation. The fluid flow and heat transfer in the computational domain satisfied the continuity equation, the momentum equation, and the energy equation. The standardk-ε two-equation turbulence model was used in this paper. In order to predict the direct illumination energy source that results from incident solar radiation and the radiation field inside the collector, the discrete ordinate radiation model with a solar ray-tracing model was used. A commercial computational fluid dynamics program (Fluent 6.3 CFD software) was used to solve the coupled fluid flow, heat transfer, and the radiation equation. The solver used is the segregated solver. Body Force Weighted was selected as the discretization method for pressure, and the SIMPLE algorithm was used to resolve the coupling between pressure and velocity. The discretization methods for the solving of momentum, energy, radiation, and turbulence were second order upwind. The thermal performance could be achieved by simulation results under different conditions. Then, the experimental and numerical results were compared to validate the prediction of the CFD model. The results showed that the numerical results of the thermal efficiency of the novel collector were in reasonable agreement with the experimental data. The validated CFD model was used to analyze the properties of the insulation layer. First, the effects of the thickness of solid insulation on the thermal performance of the collector were simulated using the numerical model. It indicated that when the thickness of solid insulation was 0.02, 0.03, 0.04, and 0.05W/(m·K) respectively, the optimum thickness of solid insulation was respectively 4.5, 5.0, 5.5, and 5.5 cm respectively. Then, in order to save cost, a new concept of the hollow insulation was presented on the insulation design of the collector, namely the combination of an air layer and a solid insulation layer. The simulations were conducted for the collector with a different size of the hollow insulation. The thermal efficiency comparison results of the collector for the hollow insulation and the solid insulation resulted in the following conclusions: 1) When the thickness of insulation was 4cm, the collector of hollow insulation with combination of 2 cm air layer and 2 cm solid insulation could get the same thermal performance as the solid insulation. And 25%-50% of the cost and weight of the insulation were saved. 2) When the thickness of insulation was 5cm, the collector of hollow insulation with combination of 2 cm air layer and 3 cm solid insulation could get the same thermal performance as the solid insulation. And nearly 40% of the cost and weight of the collector were saved. 3) When the thickness of insulation was 6cm, the collector of hollow insulation with combination of 3 cm air layer and 3 cm solid insulation could get the same thermal performance as the solid insulation. Nearly 50% of the cost and weight of the insulation were saved. Therefore, a reasonable design of the hollow insulation could obtain the same resemblance thermal insulation effect as the solid insulation collector, but the cost and weight could decrease from 25%-50%.