API 670 Machinery Protection Systems was updated in 2014. After the upgrade, higher requirements are put forward for the compressor control system. The compressor control system and interlock control are introduced. I...API 670 Machinery Protection Systems was updated in 2014. After the upgrade, higher requirements are put forward for the compressor control system. The compressor control system and interlock control are introduced. Including compressor anti surge control, performance control, turbine speed regulation control and control oil, lubricating oil, condensate control, the control of period between gas and liquid separator liquid level control, sealing gas control and overspeed protection, and some craft interlock protection system, and combined with the requirements of API 670 -- 2014 gives the solution in the practical engineering.展开更多
A large-scale compressor set of a 2 kW helium cryoplant, as one of the subsystems of EAST （the experimental advanced superconducting tokamak）, is arranged in a two-stage seriesparallel structure. A fully automatic c...A large-scale compressor set of a 2 kW helium cryoplant, as one of the subsystems of EAST （the experimental advanced superconducting tokamak）, is arranged in a two-stage seriesparallel structure. A fully automatic control system used to handle the compressors＇ on/off/ scheduling and the pressures＇ adjustment was developed. To reduce the long time lag and the uncertainty with the energy slide valves effectively, expert rules in combination with proportional- integral-derivative （PID） algorithms were applied nisms were built up to reinforce its stability and to the EAST operations and is operated stably. system, such as the big overshoot of pressure and Safety protection and status analysis mecha- robustness. The new system has been applied The problems in the previous semi-automatic complexity of the operations, were solved.展开更多
An experimental investigation conducted in a high-speed plane cascade wind tunnel demonstrates that unsteady flow control by using synthetic （zero mass flux） vortex generator jets can effectively improve the aerodyn...An experimental investigation conducted in a high-speed plane cascade wind tunnel demonstrates that unsteady flow control by using synthetic （zero mass flux） vortex generator jets can effectively improve the aerodynamic performances and reduce （or eliminate） flow separation in axial compressor cascade. The Mach number of the incoming flow is up to 0.7 and most tested cases are at Ma = 0.3. The incidence is 10° at which the boundary layer is separated from 70% of the chord length. The roles of excitation frequency, amplitude, location and pitch angle are investigated. Preliminary results show that the excitation amplitude plays a very important role, the optimal excitation location is just upstream of the separation point, and the optimal pitch angle is 35°. The maximum relative reduction of loss coefficient is 22.8%.展开更多
An improved model of reciprocating compressor operation cycle with a stepless capacity control system is presented and influence of the key parameters of the system is evaluated. In the stepless capacity control syste...An improved model of reciprocating compressor operation cycle with a stepless capacity control system is presented and influence of the key parameters of the system is evaluated. In the stepless capacity control system of a reciprocating compressor,mechanical unloaders are used to partially hold suction valves open for a certain time during the compression stroke. The typical working process of the reciprocating compressor is changed by capacity regulation apparatus. However,some critical parameters like the hydraulic force acting at the unloader have not been rigorously studied in previous researches. Here an improved numerical model of a double acting reciprocating compressor under the control stepless capacity is proposed and verified by experimental trials. Numerical simulations are carried out to select and evaluate the acting force which definitely has an influence on indicator diagrams of compressors. It is observed that the optimized range of 350 N to 380 N is preferable for the unloader force such that the intensity of opening and closing impacts are minimized.展开更多
An aerodynamic optimization method for axial flow compressor blades available for engineering is developed in this paper. Bezier surface is adopted as parameterization method to control the suction surface of the blad...An aerodynamic optimization method for axial flow compressor blades available for engineering is developed in this paper. Bezier surface is adopted as parameterization method to control the suction surface of the blades, which brings the following advantages:(A) significantly reducing design variables;(B) easy to ensure the mechanical strength of rotating blades;(C) better physical understanding;(D) easy to achieve smooth surface. The Improved Artificial Bee Colony(IABC) algorithm, which significantly increases the convergence speed and global optimization ability, is adopted to find the optimal result. A new engineering optimization tool is constructed by combining the surface parametric control method, the IABC algorithm, with a verified Computational Fluid Dynamics(CFD) simulation method, and it has been successfully applied in the aerodynamic optimization for a single-row transonic rotor(Rotor 37) and a single-stage transonic axialflow compressor(Stage 35). With the constraint that the relative change in the flow rate is less than0.5% and the total pressure ratio does not decrease, within the acceptable time in engineering, the adiabatic efficiency of Rotor 37 at design point increases by 1.02%, while its surge margin 0.84%,and the adiabatic efficiency of Stage 35 0.54%, while its surge margin 1.11% after optimization, to verify the effectiveness and potential in engineering of this new tool for optimization of axial compressor blade.展开更多
In this paper, the design of the centrifugal compressor, how scientific and rational design can effectively avoid the happening of compressor surge, combined with the current centrifugal compression pant of vibration ...In this paper, the design of the centrifugal compressor, how scientific and rational design can effectively avoid the happening of compressor surge, combined with the current centrifugal compression pant of vibration control main method and the scientific method, the system shows that the causes of the formation of compressor surge, the surge design the main principle, how to efficiently control the difficulty of implementing compression pant of vibration technology, and proposes the corresponding improvement measures are the main purpose is to improve the normal operation of the centrifugal compressor.展开更多
The resistance torque of a piston stage II com- pressor generates strenuous fluctuations in a rotational period, and this can lead to negative influences on the working performance of the compressor. To restrain the s...The resistance torque of a piston stage II com- pressor generates strenuous fluctuations in a rotational period, and this can lead to negative influences on the working performance of the compressor. To restrain the strenuous fluctuations in the piston stage II compressor, a variable duty-cycle control method based on the resistance torque is proposed. A dynamic model of a stage II com- pressor is set up, and the resistance torque and other characteristic parameters are acquired as the control tar- gets. Then, a variable duty-cycle control method is applied to track the resistance torque, thereby improving the working performance of the compressor. Simulated results show that the compressor, driven by the proposed method, requires lower current, while the rotating speed and the output torque remain comparable to the traditional vari- able-frequency control methods. A variable duty-cycle control system is developed, and the experimental results prove that the proposed method can help reduce the specific power, input power, and working noise of the compressor to 0.97 kW.m-3.min-1, 0.09 kW and 3.10 dB, respectively, under the same conditions of discharge pressure of 2.00 MPa and a discharge volume of 0.095 m3/rain. The proposed variable duty-cycle control method tracks the resistance torque dynamically, and improves the working performance of a Stage II Compressor. The pro- posed variable duty-cycle control method can be applied to other compressors, and can provide theoretical guidance for the compressor.展开更多
A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of...A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of pneumatic valve the displacement is controlled by electronic control valve. In order to know the control mechanism well and get a good control effect, a mathematical model for the variable displacement mechanism is developed according to the geometrical and kinematical information of the compressor. Using the model, the effect of relevant parameters on variable displace control is estimated. It is helpful to make the optimum decision in the flow control of AAC. As the novel displacement control device, the structure and control rule of electronic control valve is introduced. It can get better effect than the conventional pneumatic valves. And by using this new electronic control device, the optimum systemic control of AAC is available.展开更多
文摘API 670 Machinery Protection Systems was updated in 2014. After the upgrade, higher requirements are put forward for the compressor control system. The compressor control system and interlock control are introduced. Including compressor anti surge control, performance control, turbine speed regulation control and control oil, lubricating oil, condensate control, the control of period between gas and liquid separator liquid level control, sealing gas control and overspeed protection, and some craft interlock protection system, and combined with the requirements of API 670 -- 2014 gives the solution in the practical engineering.
基金supported by National Meg-science Engineering Project of the Chinese Government,[1998]1303
文摘A large-scale compressor set of a 2 kW helium cryoplant, as one of the subsystems of EAST （the experimental advanced superconducting tokamak）, is arranged in a two-stage seriesparallel structure. A fully automatic control system used to handle the compressors＇ on/off/ scheduling and the pressures＇ adjustment was developed. To reduce the long time lag and the uncertainty with the energy slide valves effectively, expert rules in combination with proportional- integral-derivative （PID） algorithms were applied nisms were built up to reinforce its stability and to the EAST operations and is operated stably. system, such as the big overshoot of pressure and Safety protection and status analysis mecha- robustness. The new system has been applied The problems in the previous semi-automatic complexity of the operations, were solved.
基金The project supported by the National Natural Science Foundation of China (10477002 and 50476003)the Ph.D. Innovative Foundation of Beihang University
文摘An experimental investigation conducted in a high-speed plane cascade wind tunnel demonstrates that unsteady flow control by using synthetic （zero mass flux） vortex generator jets can effectively improve the aerodynamic performances and reduce （or eliminate） flow separation in axial compressor cascade. The Mach number of the incoming flow is up to 0.7 and most tested cases are at Ma = 0.3. The incidence is 10° at which the boundary layer is separated from 70% of the chord length. The roles of excitation frequency, amplitude, location and pitch angle are investigated. Preliminary results show that the excitation amplitude plays a very important role, the optimal excitation location is just upstream of the separation point, and the optimal pitch angle is 35°. The maximum relative reduction of loss coefficient is 22.8%.
基金Supported by the National Key Research and Development Plan(No.2016YFF0203305)the National High Technology Research and Development Programme of China(No.2014AA041806)the Fundamental Research Funds for the Central Universities(No.ZY1617)
文摘An improved model of reciprocating compressor operation cycle with a stepless capacity control system is presented and influence of the key parameters of the system is evaluated. In the stepless capacity control system of a reciprocating compressor,mechanical unloaders are used to partially hold suction valves open for a certain time during the compression stroke. The typical working process of the reciprocating compressor is changed by capacity regulation apparatus. However,some critical parameters like the hydraulic force acting at the unloader have not been rigorously studied in previous researches. Here an improved numerical model of a double acting reciprocating compressor under the control stepless capacity is proposed and verified by experimental trials. Numerical simulations are carried out to select and evaluate the acting force which definitely has an influence on indicator diagrams of compressors. It is observed that the optimized range of 350 N to 380 N is preferable for the unloader force such that the intensity of opening and closing impacts are minimized.
基金supported by the National Natural Science Foundation of China(No.51576007)Civil Aircraft Special Research of China(No.MJZ-016-D-30)
文摘An aerodynamic optimization method for axial flow compressor blades available for engineering is developed in this paper. Bezier surface is adopted as parameterization method to control the suction surface of the blades, which brings the following advantages:(A) significantly reducing design variables;(B) easy to ensure the mechanical strength of rotating blades;(C) better physical understanding;(D) easy to achieve smooth surface. The Improved Artificial Bee Colony(IABC) algorithm, which significantly increases the convergence speed and global optimization ability, is adopted to find the optimal result. A new engineering optimization tool is constructed by combining the surface parametric control method, the IABC algorithm, with a verified Computational Fluid Dynamics(CFD) simulation method, and it has been successfully applied in the aerodynamic optimization for a single-row transonic rotor(Rotor 37) and a single-stage transonic axialflow compressor(Stage 35). With the constraint that the relative change in the flow rate is less than0.5% and the total pressure ratio does not decrease, within the acceptable time in engineering, the adiabatic efficiency of Rotor 37 at design point increases by 1.02%, while its surge margin 0.84%,and the adiabatic efficiency of Stage 35 0.54%, while its surge margin 1.11% after optimization, to verify the effectiveness and potential in engineering of this new tool for optimization of axial compressor blade.
基金supported by the National Natural Science Foundation of China (No. 51676007, No. 51376001, No. 51420105008)supported by the China Scholarship council (CSC)
文摘In this paper, the design of the centrifugal compressor, how scientific and rational design can effectively avoid the happening of compressor surge, combined with the current centrifugal compression pant of vibration control main method and the scientific method, the system shows that the causes of the formation of compressor surge, the surge design the main principle, how to efficiently control the difficulty of implementing compression pant of vibration technology, and proposes the corresponding improvement measures are the main purpose is to improve the normal operation of the centrifugal compressor.
基金Supported by National Natural Science Foundation of China(Grant No.51275452)Zhejiang Provincical Natural Science Foundation of China(Grant No.LY14E050021)Commonweal Technology Project of Science and Technology Department of Zhejiang Province,China(Grant No.2015C31071)
文摘The resistance torque of a piston stage II com- pressor generates strenuous fluctuations in a rotational period, and this can lead to negative influences on the working performance of the compressor. To restrain the strenuous fluctuations in the piston stage II compressor, a variable duty-cycle control method based on the resistance torque is proposed. A dynamic model of a stage II com- pressor is set up, and the resistance torque and other characteristic parameters are acquired as the control tar- gets. Then, a variable duty-cycle control method is applied to track the resistance torque, thereby improving the working performance of the compressor. Simulated results show that the compressor, driven by the proposed method, requires lower current, while the rotating speed and the output torque remain comparable to the traditional vari- able-frequency control methods. A variable duty-cycle control system is developed, and the experimental results prove that the proposed method can help reduce the specific power, input power, and working noise of the compressor to 0.97 kW.m-3.min-1, 0.09 kW and 3.10 dB, respectively, under the same conditions of discharge pressure of 2.00 MPa and a discharge volume of 0.095 m3/rain. The proposed variable duty-cycle control method tracks the resistance torque dynamically, and improves the working performance of a Stage II Compressor. The pro- posed variable duty-cycle control method can be applied to other compressors, and can provide theoretical guidance for the compressor.
文摘A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of pneumatic valve the displacement is controlled by electronic control valve. In order to know the control mechanism well and get a good control effect, a mathematical model for the variable displacement mechanism is developed according to the geometrical and kinematical information of the compressor. Using the model, the effect of relevant parameters on variable displace control is estimated. It is helpful to make the optimum decision in the flow control of AAC. As the novel displacement control device, the structure and control rule of electronic control valve is introduced. It can get better effect than the conventional pneumatic valves. And by using this new electronic control device, the optimum systemic control of AAC is available.
