Dongfang Turbine Co.

Deyang, China

Dongfang Turbine Co.

Deyang, China
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Wang J.,Xi'an Jiaotong University | Yan Z.,Xi'an Jiaotong University | Wang M.,Xi'an Jiaotong University | Ma S.,Xi'an Jiaotong University | And 2 more authors.
Energy | Year: 2013

Organic Rankine cycle can effectively recover the low grade heat source due to its distinctive thermodynamic performance. Based on the thermodynamic mathematical models of an ORC (organic Rankine cycle) system, this study examines the effects of key thermodynamic design parameters, including turbine inlet pressure, turbine inlet temperature, pinch temperature difference and approach temperature difference in (heat recovery vapor generator) HRVG, on the net power output and surface areas of both the HRVG and the condenser using R123, R245fa and isobutane. Considering the economic factor for the system optimization design, a ratio of net power output to total heat transfer area is selected as the performance evaluation criterion to predict the system performance from the view of both thermodynamics and economics. Genetic algorithm is employed to optimize the system performance. The results show that turbine inlet pressure, turbine inlet temperature, pinch temperature difference and approach temperature difference have significant effects on the net power output and surface areas of both the HRVG and the condenser. By parametric optimization, the ORC system with isobutane has the best system performance than that with R123 or R245fa. The optimum pinch temperature difference and approach temperature difference are generally located at upper boundary over their parametric design ranges. © 2012 Elsevier Ltd.


Wang J.,Xi'an Jiaotong University | Sun Z.,Xi'an Jiaotong University | Dai Y.,Xi'an Jiaotong University | Ma S.,Dongfang Turbine Co.
Applied Energy | Year: 2010

Supercritical CO2 power cycle shows a high potential to recover low-grade waste heat due to its better temperature glide matching between heat source and working fluid in the heat recovery vapor generator (HRVG). Parametric analysis and exergy analysis are conducted to examine the effects of thermodynamic parameters on the cycle performance and exergy destruction in each component. The thermodynamic parameters of the supercritical CO2 power cycle is optimized with exergy efficiency as an objective function by means of genetic algorithm (GA) under the given waste heat condition. An artificial neural network (ANN) with the multi-layer feed-forward network type and back-propagation training is used to achieve parametric optimization design rapidly. It is shown that the key thermodynamic parameters, such as turbine inlet pressure, turbine inlet temperature and environment temperature have significant effects on the performance of the supercritical CO2 power cycle and exergy destruction in each component. It is also shown that the optimum thermodynamic parameters of supercritical CO2 power cycle can be predicted with good accuracy using artificial neural network under variable waste heat conditions. © 2009 Elsevier Ltd. All rights reserved.


Li M.,Xi'an Jiaotong University | Wang J.,Xi'an Jiaotong University | He W.,Xi'an Jiaotong University | Gao L.,Thermal Power Research Institute | And 4 more authors.
Renewable Energy | Year: 2013

Higher efficiencies and optimal utilization of geothermal energy require a careful analysis of Organic Rankine Cycle (ORC) which is suitable for converting electric power from low-temperature heat sources. The objective of this study is to experimentally analyze the effect of varying working fluid mass flow rate and the regenerator on the efficiency of the regenerative ORC operating on R123. As R123 presents a low boiling point temperature (27.82 °C), a technology was invented to address the leakage issue when transferring R123 between the inside and outside of the regenerative ORC system. A specially manufactured throttle valve was adopted in the bypass subsystem to protect the turbine during the starting and closing processes and a novel phenomenon was discovered during the test. A preliminary test of the system was conducted with a geothermal source temperature of 130 °C. The experimental results show that the power output is 6 kW and the regenerative ORC efficiency is 7.98%, which is higher than that of the basic ORC by 1.83%. © 2013 Elsevier Ltd.


Ma S.,Xi'an Jiaotong University | Ma S.,Dongfang Turbine Co. | Wang J.,Xi'an Jiaotong University | Yan Z.,Xi'an Jiaotong University | And 2 more authors.
Journal of Power Sources | Year: 2011

Although a solid oxide fuel cell combined with a gas turbine (SOFC-GT) has good performance, the temperature of exhaust from gas turbine is still relatively high. In order to recover the waste heat of exhaust from the SOFC-GT to enhance energy conversion efficiency as well as to reduce the emissions of greenhouse gases and pollutants, in this study a new combined cooling, heat and power (CCHP) system driven by the SOFC is proposed to perform the trigeneration by using ammonia-water mixture to recover the waste heat of exhaust from the SOFC-GT. The CCHP system, whose main fuel is methane, can generate electricity, cooling effect and heat effect simultaneously. The overall system performance has been evaluated by mathematical models and thermodynamic laws. A parametric analysis is also conducted to examine the effects of some key thermodynamic parameters on the system performance. Results indicate that the overall energy conversion efficiency exceeds 80% under the given conditions, and it is also found that the increasing the fuel flow rate can improve overall energy conversion efficiency, even though both the SOFC efficiency and electricity efficiency decrease. Moreover, with an increased compressor pressure ratio, the SOFC efficiency, electricity efficiency and overall energy conversion efficiency all increase. Ammonia concentration and pressure entering ammonia-water turbine can also affect the CCHP system performance. © 2011 Elsevier B.V. All rights reserved.


Liu H.,Xi'an Jiaotong University | Liu Y.,Xi'an Jiaotong University | Wang W.,Dongfang Turbine Co.
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2011

Using a rough body-rigid plane contact model, the accuracy of the general normal stiffness equivalent method of contact interface is analyzed under both elastic and elastic-plastic material. The results show that there is a significant error while dealing with elastic-plastic materials, and the essential reason is that the general equivalent method cannot consider the plastic effect of materials completely. By making the elastic-plastic contact system equivalent to an interfacial contact layer and a non-interface block, the original system can be accurately equivalent, because the contact layer includes all the plastic effect. However, introducing the contact layer with a certain thickness can bring the problem of enlarging more elements and inconvenience for practical engineering. In order to overcome the weakness, a new equivalent method of normal contact stiffness is presented by separating the normal stiffness of the contact layer further. Using this method, the contact system is equivalent to non-thickness homogeneous spring and an elastic-plastic block with original size. In this way, the original system can be accurately equivalent, and the plastic effect of the contact body can be taken into account completely. Furthermore, the new equivalent method has nothing with the thickness of plastic zone, so it is convenient for meshing the original system. The results of typical example show the accuracy and effectiveness of the new method. © 2011 Journal of Mechanical Engineering.


Wang J.,Xi'an Jiaotong University | Yan Z.,Xi'an Jiaotong University | Ma S.,Xi'an Jiaotong University | Ma S.,Dongfang Turbine Co. | Dai Y.,Xi'an Jiaotong University
International Journal of Hydrogen Energy | Year: 2012

A new integrated power generation system driven by the solid oxide fuel cell (SOFC) is proposed to improve the conversion efficiency of conventional energy by using a Kalina cycle to recover the waste heat of exhaust from the SOFC-GT. The system using methane as main fuel consists an internal reforming SOFC, an after-burner, a gas turbine, preheaters, compressors and a Kalina cycle. The proposed system is simulated based on the developed mathematical models, and the overall system performance has been evaluated by the first and second law of thermodynamics. Exergy analysis is conducted to indicate the thermodynamic losses in each components. A parametric analysis is also carried out to examine the effects of some key thermodynamic parameters on the system performance. Results indicate that as compressor pressure ratio increases, SOFC electrical efficiency increases and there is an optimal compressor pressure ratio to reach the maximum overall electrical efficiency and exergy efficiency. It is also found that SOFC electrical efficiency, overall electrical efficiency and exergy efficiency can be improved by increasing air flow rate. Also, the largest exergy destruction occurs in the SOFC followed by the after-burner, the waste heat boiler, the gas turbine. The compressor pressure ratio and air flow rate have significant effects on the exergy destruction in some main components of system. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Ma D.,Dongfang Turbine Co. | Ma D.,State Key Laboratory of Long Life High Temperature Materials
Jinshu Xuebao/Acta Metallurgica Sinica | Year: 2016

Freckles are a detrimental grain defect formed during directional and single crystal solidification of superalloy components leading to a high rejection rate. Based on the experimental and theoretical studies over the past forty years, the occurrence of freckles is generally believed to be mainly dependent on the alloy chemistry and process parameters, while the geometrical factor of castings was hardly taken into account. In the present work, a series of superalloy castings with complex geometry were directionally solidified in a production- scale Bridgman furnace. Some new features of freckle appearance have been observed, indicating new aspects of freckle formation. The freckles are preferably formed on the edges instead of on the plane surfaces of the castings. Correspondingly, freckles were found exclusively on the casting surface having positive curvature, whereas no freckles formed on the surface with negative one. The casting portions having inward sloping surfaces are very freckle prone, while those with outward sloping surfaces are absolutely freckle free. Therefore, as an independent factor the geometrical feature of the castings can more effectively affect the freckle formation than the local thermal conditions. It was also observed that freckles could occur not only on the external surfaces, but also inside the castings where a core was inserted, because both the shell and the core wall can provide very high permeability for freckling convection in the mushy zone. Based on this wall effect, all the important phenomena observed in the present work, such as the edge effect, the step effect, the sloping effect and the curvature effect on freckle formation in complex castings of superalloys, can be reasonably explained. © All right reserved.


Gou P.-F.,Zhejiang University | Gou P.-F.,Dongfang Turbine Co. | Zhu W.-P.,Zhejiang University | Shen Z.-Q.,Zhejiang University
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2010

Novel calixarene-centered amphiphilic A2B2 miktoarm star copolymers composed of two PCL arms and two PEG arms with calix[4]arene as core moiety were synthesized by the combination of CROP and "click" chemistry. First, a heterotetrafunctional calix[4]arene derivative with two hydroxyl groups and two alkyne groups was designed as a macroinitiator to prepare calixarene-centered PCL homopolymers (C4-PCL) by CROP in the presence of Sn(Oct)2 as catalyst at 110 °C. Next, azide-terminated PEG (A-PEG) was synthesized by tandem treating methoxy poly(ethylene glycol)s (mPEG) with 4-chlorobutyryl chloride and NaN3. Finally, copper(I)-catalyzed cycloaddition reaction between C4-PCL and A-PEG led to A2B 2 miktoarm star copolymer [C4S(PCL)2-(PEG)2]. 1H NMR, FT-IR, and SEC analyses confirmed the well-defined miktoarm star architecture. These amphiphilic miktoarm star copolymers could self-assemble into multimorphological aggregates in water. The calix[4]arene moieties with a cavity <1 nm on the hydrophilic/hydrophobic interface of these aggregates may provide potential opportunities to entrap guest molecules for special applications in supermolecular science. © 2010 Wiley Periodicals, Inc.


Patent
Dongfang Turbine Co. | Date: 2012-09-21

A jet type condenser comprises a shell (8). A plurality of multilayered inner water chambers (3,4) is arranged in the shell, multilayered outer water chambers (9,10) being correspondingly in communication with the inner water chambers (3,4) are arranged outside the shell (8), each of the outer water chambers (9,10) is in communication with a water source, the lower portion of the inner water chamber (4) in a bottom layer is an air-cooling area (6), and a water guiding tube (16) in communication with the air-cooling area (6) is arranged at the bottom of the inner water chamber (4) of the bottom layer. A transverse partition board (5) is disposed in the inner water chamber (4) of the bottom layer, the inner space of the inner water chamber (4) of the bottom layer is divided into an upper cavity and a lower cavity (4-1, 4-2) which are independent, and correspondingly, the outer water chamber (10) corresponding to the inner water chamber (4) of the bottom layer is also divided into two independent cavities (10-1, 10-2) being respectively in communication with the two cavities (4-1, 4-2) of the inner water chamber (4) of the bottom layer and respectively connected with the water source. The use range of the jet type condenser is expanded, the condenser depression of condensate of the condenser can be remarkably reduced, and the running thermal consumption of a unit is reduced.


Patent
Dongfang Turbine Co. | Date: 2014-10-22

A jet type condenser comprises a shell (8). A plurality of multilayered inner water chambers (3,4) is arranged in the shell, multilayered outer water chambers (9,10) being correspondingly in communication with the inner water chambers (3,4) are arranged outside the shell (8), each of the outer water chambers (9,10) is in communication with a water source, the lower portion of the inner water chamber (4) in a bottom layer is an air-cooling area (6), and a water guiding tube (16) in communication with the air-cooling area (6) is arranged at the bottom of the inner water chamber (4) of the bottom layer. A transverse partition board (5) is disposed in the inner water chamber (4) of the bottom layer, the inner space of the inner water chamber (4) of the bottom layer is divided into an upper cavity and a lower cavity (4-1, 4-2) which are independent, and correspondingly, the outer water chamber (10) corresponding to the inner water chamber (4) of the bottom layer is also divided into two independent cavities (10-1,10-2) being respectively in communication with the two cavities (4-1, 4-2) of the inner water chamber (4) of the bottom layer and respectively connected with the water source. The use range of the jet type condenser is expanded, the condenser depression of condensate of the condenser can be remarkably reduced, and the running thermal consumption of a unit is reduced.

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