As a potentially viable renewable energy, Enhanced Geothermal Systems(EGSs) extract heat from hot dry rock(HDR) reservoirs to produce electricity and heat, which promotes the progress towards carbon peaking and carbon...As a potentially viable renewable energy, Enhanced Geothermal Systems(EGSs) extract heat from hot dry rock(HDR) reservoirs to produce electricity and heat, which promotes the progress towards carbon peaking and carbon neutralization. The main challenge for EGSs is to reduce the investment cost. In the present study, thermo-economic investigations of EGS projects are conducted. The effects of geofluid mass flow rate, wellhead temperature and loss rate on the thermo-economic performance of the EGS organic Rankine cycle(ORC) are studied. A performance comparison between EGS-ORC and the EGS combined heating and power system(CHP) is presented. Considering the CO_(2)emission reduction benefits, the influence of carbon emission trading price on the levelized cost of energy(LCOE) is also presented. It is indicated that the geofluid mass flow rate is a critical parameter in dictating the success of a project. Under the assumed typical working conditions, the LCOE of EGS-ORC and EGS-CHP systems are 24.72 and 16.1 cents/k Wh, respectively. Compared with the EGS-ORC system, the LCOE of the EGS-CHP system is reduced by 35%. EGS-CHP systems have the potential to be economically viable in the future. With carbon emission trading prices of 12.76 USD/ton, the LCOE can be reduced by approximately 8.5%.展开更多
To solve the problem of swelling and agglomeration of CaCl 2 during the process of ammonia adsorption and improve the performance of mass transfer,we present a new method for the preparation of adsorbent.The CaCl 2 is...To solve the problem of swelling and agglomeration of CaCl 2 during the process of ammonia adsorption and improve the performance of mass transfer,we present a new method for the preparation of adsorbent.The CaCl 2 is first immerged into sawdust by soaking method,then the composite adsorbent is prepared by carbonizing the mixture of CaCl 2 and sawdust.The SEM image and elements analysis indicated that the new adsorbent has high porosity and uniform distribution of CaCl 2 due to carbonization under temperature of 700°C.The performance testing of ammonia adsorption showed that under the conditions of evaporation temperature of 5°C and condensation temperature of 40°C,the ammonia uptake reaches 0.204,0.253 and 0.285 kg/kg,the specific cooling power(SCP) is 868.96,540.02 and 405.16 W/kg,and the average adsorption rate is 6.79×10 4,4.22×10 4 and 3.17×10 4 kg/kg/s when the adsorption time is 5,10 and 15 min,respectively.The problems of swelling and agglomeration of CaCl 2 are solved.展开更多
To develop a new composite adsorbent with high performance,fir sawdust and CaCl2are selected as raw materials.The mass transfer is enhanced by carbonizing and activating the sawdust and heat transfer is enhanced by ad...To develop a new composite adsorbent with high performance,fir sawdust and CaCl2are selected as raw materials.The mass transfer is enhanced by carbonizing and activating the sawdust and heat transfer is enhanced by adding expanded graphite into the adsorbent.The effect of the preparation temperature and the expanded graphite content on the adsorption performance is investigated.The results show that the new adsorbent exhibits a high adsorption performance due to its high porosity,uniform distribution and high content of CaCl2and high thermal conductivity.Also,the experimental results indicate that the rate of ammonia adsorption on the adsorbent depends on the expanded graphite content and the carbonization and activation temperature.The adsorbent prepared at 500°C and with the expanded graphite content of 30%has the best performance in terms of the adsorption refrigeration,which adsorbs ammonia as high as 0.37 g g 1at 10 min.展开更多
水下压缩空气储能(underwater compressed air energy storage,UCAES)技术定压储取能,系统能量回收效率高且储能密度大,与海上风电在空间位置上天然契合。为提高UCAES的性能,构建了储取能过程数学模型,模拟分析了影响UCAES性能的关键因...水下压缩空气储能(underwater compressed air energy storage,UCAES)技术定压储取能,系统能量回收效率高且储能密度大,与海上风电在空间位置上天然契合。为提高UCAES的性能,构建了储取能过程数学模型,模拟分析了影响UCAES性能的关键因素并探索了提效技术。主要研究成果如下:1)针对数学模型的求解难题,提出了以能量回收效率最高作为目标函数和以热回收介质流量作为决策变量的求解方法,确定了空气和热回收介质的最佳质量配比;2)为明确定容和定压压缩空气储能的性能差异,通过对比分析了二者的工作过程,揭示了储罐压力的变化是影响性能的最关键因素,UCAES的能量回收效率和储能密度比定容压缩空气储能分别提高8.25%和120.82%;3)量化分析了设备性能和储能深度对储能性能的影响,指出提高膨胀机效率对能量回收效率的提升更有效,而深度直接决定了储能密度;4)提出了电加热提升膨胀机进气温度的提效技术,该技术提高了系统发电量并产生大量热能,加热用电能中约1/3又转化为电能,约60%转化为可利用热能,为北方濒海城市可再生能源规模化供暖提供了新选择。成果可为后续UCAES工程的建设和推广提供参考,可为海上风电的大规模发展提供坚实支撑。展开更多
基金financial support provided by the National Key Research and Development Program of China(No.2018YFB1501805)China Geological Survey Project(Grant No.DD2019135,and No.DD20211336)。
文摘As a potentially viable renewable energy, Enhanced Geothermal Systems(EGSs) extract heat from hot dry rock(HDR) reservoirs to produce electricity and heat, which promotes the progress towards carbon peaking and carbon neutralization. The main challenge for EGSs is to reduce the investment cost. In the present study, thermo-economic investigations of EGS projects are conducted. The effects of geofluid mass flow rate, wellhead temperature and loss rate on the thermo-economic performance of the EGS organic Rankine cycle(ORC) are studied. A performance comparison between EGS-ORC and the EGS combined heating and power system(CHP) is presented. Considering the CO_(2)emission reduction benefits, the influence of carbon emission trading price on the levelized cost of energy(LCOE) is also presented. It is indicated that the geofluid mass flow rate is a critical parameter in dictating the success of a project. Under the assumed typical working conditions, the LCOE of EGS-ORC and EGS-CHP systems are 24.72 and 16.1 cents/k Wh, respectively. Compared with the EGS-ORC system, the LCOE of the EGS-CHP system is reduced by 35%. EGS-CHP systems have the potential to be economically viable in the future. With carbon emission trading prices of 12.76 USD/ton, the LCOE can be reduced by approximately 8.5%.
基金supported by the Chinese Academy of Sciences and Foreign Experts Bureau of Guangdong under the Adsorption Refrigeration Program (Grant nos. y007y51001 and 2010004)The structure and preparation process of the new adsorbent has a patent (China Patent 20111015-1114.2)
文摘To solve the problem of swelling and agglomeration of CaCl 2 during the process of ammonia adsorption and improve the performance of mass transfer,we present a new method for the preparation of adsorbent.The CaCl 2 is first immerged into sawdust by soaking method,then the composite adsorbent is prepared by carbonizing the mixture of CaCl 2 and sawdust.The SEM image and elements analysis indicated that the new adsorbent has high porosity and uniform distribution of CaCl 2 due to carbonization under temperature of 700°C.The performance testing of ammonia adsorption showed that under the conditions of evaporation temperature of 5°C and condensation temperature of 40°C,the ammonia uptake reaches 0.204,0.253 and 0.285 kg/kg,the specific cooling power(SCP) is 868.96,540.02 and 405.16 W/kg,and the average adsorption rate is 6.79×10 4,4.22×10 4 and 3.17×10 4 kg/kg/s when the adsorption time is 5,10 and 15 min,respectively.The problems of swelling and agglomeration of CaCl 2 are solved.
基金supported by the Innovation Program of Chinese Academy of Sciences(y007y51001)Comprehensive Strategic Cooperation Projects of Chinese Academy of Sciences and Guangdong Province(2012B091100263)
文摘To develop a new composite adsorbent with high performance,fir sawdust and CaCl2are selected as raw materials.The mass transfer is enhanced by carbonizing and activating the sawdust and heat transfer is enhanced by adding expanded graphite into the adsorbent.The effect of the preparation temperature and the expanded graphite content on the adsorption performance is investigated.The results show that the new adsorbent exhibits a high adsorption performance due to its high porosity,uniform distribution and high content of CaCl2and high thermal conductivity.Also,the experimental results indicate that the rate of ammonia adsorption on the adsorbent depends on the expanded graphite content and the carbonization and activation temperature.The adsorbent prepared at 500°C and with the expanded graphite content of 30%has the best performance in terms of the adsorption refrigeration,which adsorbs ammonia as high as 0.37 g g 1at 10 min.
文摘水下压缩空气储能(underwater compressed air energy storage,UCAES)技术定压储取能,系统能量回收效率高且储能密度大,与海上风电在空间位置上天然契合。为提高UCAES的性能,构建了储取能过程数学模型,模拟分析了影响UCAES性能的关键因素并探索了提效技术。主要研究成果如下:1)针对数学模型的求解难题,提出了以能量回收效率最高作为目标函数和以热回收介质流量作为决策变量的求解方法,确定了空气和热回收介质的最佳质量配比;2)为明确定容和定压压缩空气储能的性能差异,通过对比分析了二者的工作过程,揭示了储罐压力的变化是影响性能的最关键因素,UCAES的能量回收效率和储能密度比定容压缩空气储能分别提高8.25%和120.82%;3)量化分析了设备性能和储能深度对储能性能的影响,指出提高膨胀机效率对能量回收效率的提升更有效,而深度直接决定了储能密度;4)提出了电加热提升膨胀机进气温度的提效技术,该技术提高了系统发电量并产生大量热能,加热用电能中约1/3又转化为电能,约60%转化为可利用热能,为北方濒海城市可再生能源规模化供暖提供了新选择。成果可为后续UCAES工程的建设和推广提供参考,可为海上风电的大规模发展提供坚实支撑。
