【摘要】：聚焦光伏系統(tǒng)余熱發(fā)電的研究,以導(dǎo)熱油為介質(zhì)對聚光工作下的砷化鎵電池進(jìn)行冷卻,導(dǎo)熱油帶走的余熱利用于有機(jī)朗肯循環(huán)(ORC)進(jìn)行再發(fā)電。 進(jìn)行系統(tǒng)元器件的選擇與設(shè)計,并對系統(tǒng)熱力性能做了分析。由于冷卻介質(zhì)選擇的是導(dǎo)熱油,故需對ORC循環(huán)工質(zhì)進(jìn)行匹配選擇。充分考慮各種因素,選取臭氧耗損潛值(ODP)為0的四種工質(zhì)：R600、R134a、R236fa、R245fa作為候選工質(zhì)。對工質(zhì)應(yīng)用于ORC的熱力性能做了對比分析。從熱力學(xué)第一定律分析,隨著蒸發(fā)溫度的升高,工質(zhì)的蒸發(fā)壓力、輸出凈功、熱效率以及膨脹比都是升高的；從熱力學(xué)第二定律分析,熱力完善度((?)效率)是先升高后下降,存在一個最大值,此時系統(tǒng)的總不可逆損失最小。綜合考慮,得出R245fa具有較好的環(huán)保性和安全性,以及較高的熱效率和熱力完善度；適用于低溫余熱有機(jī)朗肯循環(huán)發(fā)電系統(tǒng)。 太陽能砷化鎵電池與導(dǎo)熱油的光熱轉(zhuǎn)換實(shí)驗(yàn),聚光下的砷化鎵電池采用導(dǎo)熱油冷卻與水冷和風(fēng)冷同時進(jìn)行實(shí)驗(yàn)。結(jié)果表明：三種冷卻方式中,導(dǎo)熱油冷卻與水冷和風(fēng)冷相比,砷化鎵電池的平均溫度分別降低了5.75℃和40.04℃；平均輸出功率高出0.69W和4.81W；平均轉(zhuǎn)換效率提高了1.83%和11.96%。 為了平衡ORC與聚光砷化鎵電池對蒸發(fā)溫度的不同要求,需要對ORC的蒸發(fā)溫度進(jìn)行優(yōu)化。首先使用層次分析法將蒸發(fā)溫度的優(yōu)化分為目標(biāo)層、準(zhǔn)則層、指標(biāo)層三個層次。準(zhǔn)則層分別為系統(tǒng)能效準(zhǔn)則、熱經(jīng)濟(jì)性準(zhǔn)則、系統(tǒng)輸出能量準(zhǔn)則。指標(biāo)層分別為總能效率、當(dāng)量(?)效率、APR(面積功率比)、VPR(體積功率比)、系統(tǒng)凈輸出功率。使用不同的指標(biāo)去優(yōu)化蒸發(fā)溫度得出的結(jié)論不一致。因此,進(jìn)一步使用層次分析法.熵值法對蒸發(fā)溫度進(jìn)行綜合評價。通過綜合評價,最后得出目標(biāo)層,蒸發(fā)溫度在76℃時,ORC的綜合評價值最高。對整個系統(tǒng)來說,蒸發(fā)溫度從85℃降到76℃,ORC熱效率降低了2.76%,而聚光砷化鎵電池轉(zhuǎn)換效率提高了3.58%；整體效率提高了0.82%。ORC輸出功率降低了17.7W,而聚光砷化鎵電池輸出功率升高了36W；整體輸出功率提高了18.3W。 搭建系統(tǒng)實(shí)驗(yàn)平臺,用電加熱作為模擬熱源,使用R22為工質(zhì),設(shè)定集熱箱中熱水溫度為80℃,進(jìn)行初步實(shí)驗(yàn)并作簡要分析。 本文研究得到廣西自然科學(xué)基金項(xiàng)目(NO.2011GXNSFA018029)、國家自然科學(xué)基金項(xiàng)目(NO.51266001)的支持。
[Abstract]:Focusing on the research of photovoltaic system waste heat generation, the heat conduction oil is used as the medium to cool the gallium arsenide cells working under concentrated light. The waste heat taken away by the heat conduction oil is used in organic Rankine cycle (ORC) to generate electricity again. The system components are selected and designed, and the thermodynamic performance of the system is analyzed. Because the cooling medium is heat conducting oil, it is necessary to match the working fluid of ORC cycle. Taking all kinds of factors into account, four kinds of working medium with ozone depletion potential value (ODP) of 0: R600 R134a1 / R236fa-R245fa were selected as candidate working medium. The thermodynamic performance of the working fluid applied to ORC is compared and analyzed. According to the first law of thermodynamics, the evaporation pressure, the output net work, the thermal efficiency and the expansion ratio of the working fluid are all increased with the rise of the evaporation temperature, and the thermal consummation degree (?) from the second law of thermodynamics. The efficiency) is that the total irreversible loss of the system is the minimum when the total irreversible loss of the system increases first and then decreases, and there is a maximum value. It is concluded that R245fa has good environmental protection, safety, high thermal efficiency and thermal consummation, and is suitable for low temperature waste heat organic Rankine cycle power generation system. The photothermal conversion experiment between solar GaAs battery and heat conduction oil was carried out. The thermal conductivity oil cooling and air cooling were used in the GaAs battery under concentrated light. The experiment was carried out at the same time as water cooling and air cooling. The results show that the average temperature of GaAs cells is reduced by 5.75 鈩，

本文編號：2396318