The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Qinhan Jin - One of the best experts on this subject based on the ideXlab platform.
-
Desolvation effect on the analytical performance of microwave-induced plasma atomic absorption spectrometry (MIP-AAS)
Spectrochimica Acta Part B: Atomic Spectroscopy, 1994Co-Authors: Yixiang Duan, Hanqi Zhang, Mingyi Huo, Qinhan JinAbstract:Abstract This paper describes an improvement of detection capability for microwave-induced plasma atomic absorption spectrometry (MIP-AAS) by using a modified desolvation system, which includes heated tubing, a Water-Cooled Condenser and a concentrated sulfuric acid desiccator. The influence of heating temperature, carrier-gas flow rate and microwave power on the analytical performance of MIP-AAS has been examined and the relationship between these experimental parameters discussed. The desolvation efficiencies of the different steps, such as in the water-cooling system and sulfuric acid desiccator, have been quantitatively measured using silica gel traps. Under the optimized experimental conditions, an overall desolvation efficiency of as high as 99% is achieved by using this recommended desolvation system. The analytical figures of merit for MIP-AAS are compared and evaluated under different desolvation conditions.
-
Evaluation of the Performance of Microwave-Induced Plasma Atomic Absorption Spectrometry (MIP-AAS)
Applied Spectroscopy, 1993Co-Authors: Yixiang Duan, Mingyi Hou, Qinhan JinAbstract:An innovative method of MIP-AAS has been developed. The sample solution was introduced by using an ultrasonic nebulizer. The desolvation was accomplished by a heating tube and a combination of a Water-Cooled Condenser and a concentrated sulfuric acid desiccator. Both an L-shaped and a T-shaped plasma discharge tube were used as the absorption cell in the experiment. The experimental parameters were carefully examined and optimized for the elements studied. Some comparison of properties for these two different absorption tubes was made, and the analytical performance of MIP-AAS was evaluated. The characteristic concentrations obtained in this work were shown to be around ppb under the optimized experimental conditions for 12 elements. Good repeatability and accuracy were achieved. The analytical figures of merit were found to be much better than those obtained by ICP-AAS and previous MIP-AAS experiments and comparable to or even better than the best reported values of flame AAS.
Xinli Wang - One of the best experts on this subject based on the ideXlab platform.
-
Refrigeration performance research and simulation of two-stage ejector with water cooled Condenser
2017 Chinese Automation Congress (CAC), 2017Co-Authors: Jie Deng, Lei Wang, Xinli WangAbstract:In order to make the ejector refrigeration system reach subzero refrigeration, the ejector structure is optimized in this paper. A two-stage ejector model in series with two ejectors is proposed. Comparing with traditional single ejector models, the two-stage ejector carries out a two boost of the secondary flow by connecting two ejectors in series. Using a water cooled Condenser can also reduce the outlet pressure. Thus the pressure burden of a single ejector is reduced. The effectiveness of the proposed model is validated by simulation data. It is shown that the minimum refrigerating temperature of the two-stage ejector can achieve the refrigeration temperature requirement.
-
Area ratio optimization of an ejector refrigeration system with Water-Cooled Condenser
2017 Chinese Automation Congress (CAC), 2017Co-Authors: Wending Gu, Lei Wang, Xinli WangAbstract:Ejector has become a standard component in many refrigeration systems driven by low-grade energy. In order to lower the temperature of Condenser, and improve the performance of ejector, a Water-Cooled Condenser is used in ejector refrigeration system for marine in this paper. The mode of ejector is established in GAMBIT and the simulation is carried out in FLUENT, which is simulated at different area ratios to find out the optimum ejector size with 4 sets of different primary flow inlet's pressures, 18.651 bar, 20.891 bar, 23.332bar and 25.988bar. The results show that the corresponding optimum area ratio is 4.3, 4.9, 5.6 and 6.2, respectively. With numerical study in this paper, it is obvious that the optimum area ratio ejector can improve the performance of refrigeration system for marine.
-
Optimal design of two-stage ejector for subzero refrigeration system on fishing vessel
Applied Thermal Engineering, 1Co-Authors: Xinli Wang, Jie Deng, Lei Wang, Yajie Song, Youjie ZhanAbstract:Abstract It is essential to improve the energy efficiency of the subzero refrigeration system on fishing vessels for harvested fishery products frozen because of its large amounts of fossil consumption. In this paper, a subzero refrigeration system based on a two-stage ejector is proposed and the optimal design method of the two-stage ejector considering Area ratio (Ars) as the designed parameter in each stage is developed to achieve maximum entrainment performance. A Computational Fluid Dynamics model is built to investigate the performance of the proposed two-stage ejector under subzero refrigeration working conditions. In each stage, Ar is used as the design parameter to get the maximum entrainment ratio under the feasible range of intermediate pressure. Moreover, the Water-Cooled Condenser is employed to reduce the pressure difference between the Condenser and evaporator so that a higher entrainment ratio can be achieved. Simulation results indicate that the proposed two-stage ejector can achieve evaporating temperature as low as -25℃ with an entrainment ratio as high as 0.0961, 36.12% improvement compared with the one without optimal design. Furthermore, the entrainment performance and Coefficient of Performance of subzero refrigeration system with the proposed two-stage ejector and Water-Cooled Condenser are increased by 30.57% and 28.77%, respectively, compared with the one with air-cooled Condenser. It can conclude that it is energy efficient to utilize the waste heat from fishing vessels to drive a subzero refrigeration system with the optimal designed two-stage ejector and a Water-Cooled Condenser.
Lipeng Wang - One of the best experts on this subject based on the ideXlab platform.
-
performance analysis and working fluids selection of solar powered organic rankine vapor compression ice maker
Solar Energy, 2013Co-Authors: Lipeng WangAbstract:Abstract To develop the organic Rankine cycle/vapor compression cycle (ORC/VCC) ice maker driven by solar energy, a thermodynamic model was developed, and four working fluids of R123, R245fa, R600a and R600 were selected and evaluated to identify suitable working fluids which may yield high system efficiencies. Besides, the effects of generation temperature and condensation temperature on the system performance were also analyzed. In terms of power efficiency and expander size, R600 and R600a are more suitable working fluids for ORC. Also, R600a and R600 are more appropriate working fluids for VCC in terms of pressure ratio and coefficient of performance. In terms of overall efficiency and ice production per square meter collector per day, R123 is most suitable working fluid for ORC/VCC. The generation temperature and condensation temperature have important effects on overall efficiency and ice production. There is always an optimal generation temperature at which overall efficiency and ice production can achieve the maximum values, while the generation temperature can be controlled by changing the mass flow rate of working fluid for ORC. In addition, the system performance and payback period should be comprehensively considered so as to decide to adopt air cooled or water cooled Condenser due to having different condensation temperature.
Christos N Markides - One of the best experts on this subject based on the ideXlab platform.
-
an assessment of solar powered organic rankine cycle systems for combined heating and power in uk domestic applications
Applied Energy, 2015Co-Authors: James Freeman, Klaus Hellgardt, Christos N MarkidesAbstract:Performance calculations are presented for a small-scale combined solar heat and power (CSHP) system based on an Organic Rankine Cycle (ORC), in order to investigate the potential of this technology for the combined provision of heating and power for domestic use in the UK. The system consists of a solar collector array of total area equivalent to that available on the roof of a typical UK home, an ORC engine featuring a generalised positive-displacement expander and a Water-Cooled Condenser, and a hot water storage cylinder. Preheated water from the Condenser is sent to the domestic hot water cylinder, which can also receive an indirect heating contribution from the solar collector. Annual simulations of the system are performed. The electrical power output from concentrating parabolic-trough (PTC) and non-concentrating evacuated-tube (ETC) collectors of the same total array area are compared. A parametric analysis and a life-cycle cost analysis are also performed, and the annual performance of the system is evaluated according to the total electrical power output and cost per unit generating capacity. A best-case average electrical power output of 89W (total of 776kWh/year) plus a hot water provision capacity equivalent to ∼80% of the total demand are demonstrated, for a whole system capital cost of £2700–£3900. Tracking PTCs are found to be very similar in performance to non-tracking ETCs with an average power output of 89W (776kWh/year) vs. 80W (701kWh/year).
Sanjay - One of the best experts on this subject based on the ideXlab platform.
-
Exergy analysis of effect of air/fuel ratio and compression ratio on rational efficiency of gas/steam combined cycle
Journal of the Energy Institute, 2013Co-Authors: Nitul Kumar, SanjayAbstract:AbstractThe paper presents exergy analysis of a gas/steam combined cycle also called gas turbine combined cycle. The second law approach has been used to evaluate component wise exergy destruction for different values of investigated parameters. The cycle components, i.e. compressor, gas turbine (high pressure and low pressure), combustor, heat recovery steam generator (HRSG), stack, steam turbine and water cooled Condenser have been investigated with respect to the effect of varying values of air/fuel ratio and compression ratio on the performance parameters like component-wise percentage exergy destruction and rational efficiency of gas turbine and steam turbine and the results have been presented. Results show that higher values of compression ratio and low air/fuel ratio correspond to lower exergy destruction associated with combustion. The effect of turbine exit temperature on the rational efficiency of plant has been discussed. It has been concluded that for maximising plant efficiency, turbine inle...
