热力发电
熱力髮電
열력발전
Thermal Power Generation
2015年
9期
37-42
,共6页
太阳能发电%热管吸热器%相变%空穴%蓄热单元%蓄/放热过程
太暘能髮電%熱管吸熱器%相變%空穴%蓄熱單元%蓄/放熱過程
태양능발전%열관흡열기%상변%공혈%축열단원%축/방열과정
solar power generation%heat pipe receiver%phase change%void cavity%heat storage unit%heat
基于微重力条件下的导热控制微分方程，采用焓法建立热管吸热器相变蓄热单元计算模型，对微重力条件下热管吸热器蓄热容器的相变传热过程进行了模拟计算，分析了空穴率对蓄热容器内部的温度场和热性能的影响。结果表明：经与美国国家航空航天局(NASA)方案进行比较，所建立的计算模型合理、准确，能够较好地模拟热管吸热器蓄热单元蓄、放热过程；热管吸热器壁温与相变蓄热容器温度非常接近，包含着相变材料的整个热管起着均匀热负荷的作用，与基本型吸热器相比热管吸热器相变材料熔化率大幅提高，相变材料利用率较高；随着空穴率的增大，相变材料利用率降低，相变材料容器的蓄热能力降低，同时相变蓄热容器内温度梯度增大，可能导致该处热应力过大，从而降低其使用寿命。
基于微重力條件下的導熱控製微分方程，採用焓法建立熱管吸熱器相變蓄熱單元計算模型，對微重力條件下熱管吸熱器蓄熱容器的相變傳熱過程進行瞭模擬計算，分析瞭空穴率對蓄熱容器內部的溫度場和熱性能的影響。結果錶明：經與美國國傢航空航天跼(NASA)方案進行比較，所建立的計算模型閤理、準確，能夠較好地模擬熱管吸熱器蓄熱單元蓄、放熱過程；熱管吸熱器壁溫與相變蓄熱容器溫度非常接近，包含著相變材料的整箇熱管起著均勻熱負荷的作用，與基本型吸熱器相比熱管吸熱器相變材料鎔化率大幅提高，相變材料利用率較高；隨著空穴率的增大，相變材料利用率降低，相變材料容器的蓄熱能力降低，同時相變蓄熱容器內溫度梯度增大，可能導緻該處熱應力過大，從而降低其使用壽命。
기우미중력조건하적도열공제미분방정，채용함법건립열관흡열기상변축열단원계산모형，대미중력조건하열관흡열기축열용기적상변전열과정진행료모의계산，분석료공혈솔대축열용기내부적온도장화열성능적영향。결과표명：경여미국국가항공항천국(NASA)방안진행비교，소건립적계산모형합리、준학，능구교호지모의열관흡열기축열단원축、방열과정；열관흡열기벽온여상변축열용기온도비상접근，포함착상변재료적정개열관기착균균열부하적작용，여기본형흡열기상비열관흡열기상변재료용화솔대폭제고，상변재료이용솔교고；수착공혈솔적증대，상변재료이용솔강저，상변재료용기적축열능력강저，동시상변축열용기내온도제도증대，가능도치해처열응력과대，종이강저기사용수명。
On the basis of thermal conduction differential equations under microgravity condition,the enthal-py method was applied to establish calculation model for phase change heat storage unit in heat pipe receiv-ers.Considering both the void cavity and phase change,numerical simulation was carried out.The effects of void cavity on temperature field and thermal performance of the phase change material (PCM)canister were investigated.The results show that,compared with the National Aeronautics and Space Administra-tion (NASA)results,the established model is reasonable and accurate,which can well simulate the heat storage and release process of the PCM canister.The wall temperature of the heat pipe receiver is close to that of the PCM canister,implying the entire heat pipe containing PCM plays a role in heat load uniformi-ty.The maximum melting rate of the PCM is 92%,indicating the utilization efficiency of the PCM is high. With an increase in void cavity,the unmelted PCM amount increases in the area close to the void during the last stage of solar radiation and the unconsolidated PCM amount increased during the last stage of shadow, indicating the PCM's utilization efficiency decreased and the PCM tank's heat storage capability reduced. Moreover,the temperature gradient in the PCM heat storage tank increased,which may cause over high thermal stress,leading to a decrease in the tank's service life.
