A new type of liquid desiccant water chiller for applications on air-conditioning and refrigeration is introduced.The system can be driven by low-grade heat sources with temperatures of 60 to 80 ℃,which can be easily...A new type of liquid desiccant water chiller for applications on air-conditioning and refrigeration is introduced.The system can be driven by low-grade heat sources with temperatures of 60 to 80 ℃,which can be easily obtained by a flat plat solar collector,waste heat,etc.A numerical model is developed to study the system performance.The effects of different parameters on performance are discussed,including evaporating temperature,regenerating temperature,ambient condition,and mass flow rates of closed moist air and regenerating air.The results show that an acceptable performance of a cooling capacity of 2.5 kW and a coefficient of performance of 0.37 can be achieved in a reference case.The regenerating temperature and the humidity ratios of ambient air are two main factors affecting system performance,while the temperature of ambient air functions less.In addition,the mass flow rate of regenerating air and closed moist air should be carefully determined for economical operation.展开更多
To develop energy audits in oil and gas field enterprises has important and realistic significance. Chinese energy audit in oil and gas field enterprises is still in the exploratory stage, the paper puts forward some ...To develop energy audits in oil and gas field enterprises has important and realistic significance. Chinese energy audit in oil and gas field enterprises is still in the exploratory stage, the paper puts forward some countermeasures and proposals through the analysis on status quo to identify the shortcomings.展开更多
Biofuels could contribute, on a worldwide basis, to the attainment of international energy-policy objectives in three ways： by reducing dependence on imported oil; by increasing the availability of renewable energy s...Biofuels could contribute, on a worldwide basis, to the attainment of international energy-policy objectives in three ways： by reducing dependence on imported oil; by increasing the availability of renewable energy sources; and by dealing with environmental issues. One such environmental issue is the unsustainable use of agricultural land. There is a need in South Africa there to convert to sustainable and renewable energy resources, such as biofuels, but the production of biofuels will ultimately place pressure on the limited and fragile agricultural resources of the country. This paper sets out firstly to investigate national agricultural policies which could impact on the production of biofuels. It points out that national agricultural policies are hampering the domestic production of biofuels in that the focus is on land reform and increasing the volume of agricultural exports, whereas the provision of food and energy to meet domestic needs features only as a secondary aim. The second objective of this paper is to investigate the possibility of utilising energy crops for biofuel production in South Africa. Annual agricultural production, surplus import and export figures, provide an indication of the capacity of South African farmers to produce crops for biofuel production.展开更多
Since the reform and opening up,China's export trade has maintained a rapid growth;meanwhile,China's energy consumption has been increasing sharply. "High export and high energy consumption" has beco...Since the reform and opening up,China's export trade has maintained a rapid growth;meanwhile,China's energy consumption has been increasing sharply. "High export and high energy consumption" has become the feature of China's trade and economic development.In this paper,based on the input-output analysis approach,the authors have conducted an empirical study on the export trade and energy consumption of 21 trade industrial sectors.The results show that,China is a big net exporter of embodied energy.Assuming that the export growth rate of embodied energy maintains to be about 23.6%,the average annual growth rate of the past 32 years,and based on the input-output data of 2005,by 2030 China's net export of embodied energy would be over eight times more than the aggregate energy production,which is obviously infeasible.As a country of very low per capita energy,China must change its export pattern,encourage or restrain the export of different industrial sectors according to their energy consumption intensity,and promote structural change of energy-efficient exported products,so as to achieve the sustainable development.Accordingly,the authors put forward some suggestions.展开更多
An active pipe-embedded building envelope, which is an external wall or roof with pipes embedded inside, was presented. This structure may utilize the circulating water in the pipe to transfer heat or coolth inside di...An active pipe-embedded building envelope, which is an external wall or roof with pipes embedded inside, was presented. This structure may utilize the circulating water in the pipe to transfer heat or coolth inside directly. This kind of structure is named ＂active pipe-embedded building envelope＂ due to dealing with the thermal energy actively inside the structure mass by circulating water. This structure not only deals with thermal energy before the external disturbance becomes cooling/heating load by using the circulating water, but also may use low-grade energy sources such as evaporative cooling, solar energy, and geothermal energy. In the meantime, this structure can also improve the indoor thermal comfort by tempering the internal wall surface temperature variation due to the thermal removal in the mass. This work further presents the thermal performance of this structure under a typical hot summer weather condition by comparing it with that of the conventional external wall/roof with numerical simulation. The results show that this pipe-embedded structure may reduce the external heat transfer significantly and reduce the internal wall surface temperature for improving thermal comfort. This work also presents the effects of the water temperature and the pipe spacing on the heat transfer of this structure. The internal surface heat transfer may reduce by about 2.6 W/mE when the water temperature reduces by 1℃ as far as a brick wall with pipes embedded inside is concerned. When the pipe spacing reduces by 50 mm, the internal wall surface heat flux can also reduce by about 2.3 W/m2.展开更多
基金The National Natural Science Foundation of China(No.50976021)the National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2007BA000875)
文摘A new type of liquid desiccant water chiller for applications on air-conditioning and refrigeration is introduced.The system can be driven by low-grade heat sources with temperatures of 60 to 80 ℃,which can be easily obtained by a flat plat solar collector,waste heat,etc.A numerical model is developed to study the system performance.The effects of different parameters on performance are discussed,including evaporating temperature,regenerating temperature,ambient condition,and mass flow rates of closed moist air and regenerating air.The results show that an acceptable performance of a cooling capacity of 2.5 kW and a coefficient of performance of 0.37 can be achieved in a reference case.The regenerating temperature and the humidity ratios of ambient air are two main factors affecting system performance,while the temperature of ambient air functions less.In addition,the mass flow rate of regenerating air and closed moist air should be carefully determined for economical operation.
文摘To develop energy audits in oil and gas field enterprises has important and realistic significance. Chinese energy audit in oil and gas field enterprises is still in the exploratory stage, the paper puts forward some countermeasures and proposals through the analysis on status quo to identify the shortcomings.
文摘Biofuels could contribute, on a worldwide basis, to the attainment of international energy-policy objectives in three ways： by reducing dependence on imported oil; by increasing the availability of renewable energy sources; and by dealing with environmental issues. One such environmental issue is the unsustainable use of agricultural land. There is a need in South Africa there to convert to sustainable and renewable energy resources, such as biofuels, but the production of biofuels will ultimately place pressure on the limited and fragile agricultural resources of the country. This paper sets out firstly to investigate national agricultural policies which could impact on the production of biofuels. It points out that national agricultural policies are hampering the domestic production of biofuels in that the focus is on land reform and increasing the volume of agricultural exports, whereas the provision of food and energy to meet domestic needs features only as a secondary aim. The second objective of this paper is to investigate the possibility of utilising energy crops for biofuel production in South Africa. Annual agricultural production, surplus import and export figures, provide an indication of the capacity of South African farmers to produce crops for biofuel production.
基金interim result of China’s Strategy on Foreign Trade Development and Industrial Safety,which is the phase III construction project of "211 Project" of Shanghai University of Finance and EconomicsStudy on the Relation between Foreign Trade and China’s Energy Consumption (Grant No.:CXJJ-2009313),which is sponsored by Graduate Students Research and Innovation Fund of Shanghai University of Finance and Economics
文摘Since the reform and opening up,China's export trade has maintained a rapid growth;meanwhile,China's energy consumption has been increasing sharply. "High export and high energy consumption" has become the feature of China's trade and economic development.In this paper,based on the input-output analysis approach,the authors have conducted an empirical study on the export trade and energy consumption of 21 trade industrial sectors.The results show that,China is a big net exporter of embodied energy.Assuming that the export growth rate of embodied energy maintains to be about 23.6%,the average annual growth rate of the past 32 years,and based on the input-output data of 2005,by 2030 China's net export of embodied energy would be over eight times more than the aggregate energy production,which is obviously infeasible.As a country of very low per capita energy,China must change its export pattern,encourage or restrain the export of different industrial sectors according to their energy consumption intensity,and promote structural change of energy-efficient exported products,so as to achieve the sustainable development.Accordingly,the authors put forward some suggestions.
基金Project(51178201) supported by the National Natural Science Foundation of China Project(2011CDB292) supported by the Natural Science Foundation of Hubei Province,China
文摘An active pipe-embedded building envelope, which is an external wall or roof with pipes embedded inside, was presented. This structure may utilize the circulating water in the pipe to transfer heat or coolth inside directly. This kind of structure is named ＂active pipe-embedded building envelope＂ due to dealing with the thermal energy actively inside the structure mass by circulating water. This structure not only deals with thermal energy before the external disturbance becomes cooling/heating load by using the circulating water, but also may use low-grade energy sources such as evaporative cooling, solar energy, and geothermal energy. In the meantime, this structure can also improve the indoor thermal comfort by tempering the internal wall surface temperature variation due to the thermal removal in the mass. This work further presents the thermal performance of this structure under a typical hot summer weather condition by comparing it with that of the conventional external wall/roof with numerical simulation. The results show that this pipe-embedded structure may reduce the external heat transfer significantly and reduce the internal wall surface temperature for improving thermal comfort. This work also presents the effects of the water temperature and the pipe spacing on the heat transfer of this structure. The internal surface heat transfer may reduce by about 2.6 W/mE when the water temperature reduces by 1℃ as far as a brick wall with pipes embedded inside is concerned. When the pipe spacing reduces by 50 mm, the internal wall surface heat flux can also reduce by about 2.3 W/m2.
