The Research of Cooling Water Temperature and Flow Rate Control System Based on Heat Transfer and Neural Network

Author(s):  
Meng Lingling ◽  
Qian Xuefei
Author(s):  
Shuai Wu ◽  
Richard Burton ◽  
Zongxia Jiao ◽  
Juntao Yu ◽  
Rongjie Kang

This paper considers the feasibility of a new type of voice coil motor direct drive flow control servo valve. The proposed servo valve controls the flow rate using only a direct measurement of the spool position. A neural network is used to estimate the flow rate based on the spool position, velocity and coil current. The estimated flow rate is fed back to a closed loop controller. The feasibility of the concept is established using simulation techniques only at this point. All results are validated by computer co-simulation using AMESim and Simulink. A simulated model of a VCM-DDV (Voice Coil Motor-Direct Drive Valve) and hydraulic test circuit are built in an AMESim environment. A virtual digital controller is developed in a Simulink environment in which the feedback signals are received from the AMESim model; the controller outputs are sent to the VCM-DDV model in AMESim (by interfacing between these two simulation packages). A LQR (Linear Quadratic Regulator) state feedback and nonlinear compensator controller for spool position tracking is considered as this is the first step for flow control. A flow rate control loop is subsequently included via a neural network flow rate estimator. Simulation results show that this method could control the flow rate to an acceptable degree of precision, but only at low frequencies. This kind of valve can find usage in open loop hydraulic velocity control in many industrial applications.


Author(s):  
Jungho Lee ◽  
Cheong-Hwan Yu ◽  
Sang-Jin Park

Water spray cooling is an important technology which has been used in a variety of engineering applications for cooling of materials from high-temperature nominally up to 900°C, especially in steelmaking processes and heat treatment in hot metals. The effects of cooling water temperature on spray cooling are significant for hot steel plate cooling applications. The local heat flux measurements are introduced by a novel experimental technique in which test block assemblies with cartridge heaters and thermocouples are used to measure the heat flux distribution on the surface of hot steel plate as a function of heat flux gauge. The spray is produced from a fullcone nozzle and experiments are performed at fixed water impact density of G and fixed nozzle-to-target spacing. The results show that effects of water temperature on forced boiling heat transfer characteristics are presented for five different water temperatures between 5 to 45°C. The local heat flux curves and heat transfer coefficients are also provided to a benchmark data for the actual spray cooling of hot steel plate cooling applications.


2020 ◽  
Vol 18 (4) ◽  
pp. 578-585
Author(s):  
Madina Shavdinova ◽  
Konstantin Aronson ◽  
Nina Borissova

The condensing unit is one of the most important elements of the steam turbine of a combined heat and power plant. Defects in elements of the condensing unit lead to disturbances in the steam turbine operation, its failures and breakdowns, as well as efficiency losses of the plant. Therefore, the operating personnel need to know the cause of the malfunction and to correct it immediately. There are no diagnostic models of condensers in the Republic of Kazakhstan at the moment. In this regard, a mathematical model of a condenser based on the methodology of Kaluga Turbine Plant (KTP) has been developed. The mathematical model makes it possible to change the input parameters, plot dependency diagrams, and calculate the plant efficiency indicators. The mathematical model of the condenser can be used to research ways for the improvement of the condensing unit efficiency, for diagnostic purposes of the equipment condition, for the energy audit conduction of the plant, and in the training when performing virtual laboratory research. Using static data processing by linear regression method we obtain that the KTP methodology of condenser calculation is fair at cooling water temperature from 20 °C to 24 °C, but at cooling water temperature from 20 °C to 28 °C, the methodology of JSC "All-Russia Thermal Engineering Institute" (JSC "VTI") is used. One of the ways to increase the condenser efficiency has been proposed. It is the heat transfer augmentation with riffling annular grooves on tubes. This method increases the heat transfer coefficient by 2%, reduces the water subcooling of the heating steam by 0.9 °C, and decreases the cooling area by 2%.


2016 ◽  
Vol 28 (6) ◽  
pp. 854-861 ◽  
Author(s):  
Tadayoshi Aoyama ◽  
◽  
Amalka De Zoysa ◽  
Qingyi Gu ◽  
Takeshi Takaki ◽  
...  

[abstFig src='/00280006/09.jpg' width='300' text='Snapshots of particle sorting experiment using our system' ] On-chip cell analysis is an important issue for microtechnology research, and microfluidic devices are frequently used in on-chip cell analysis systems. One approach to controlling the fluid flow in microfluidic devices for cell analysis is to use a suitable pumps. However, it is difficult to control the actual flow-rate in a microfluidic device because of the difficulty in placing flow-rate sensors in the device. In this study, we developed a real-time flow-rate control system that uses syringe pumps and high-speed vision to measure the actual fluid flow in microfluidic devices. The developed flow-rate control system was verified through experiments on microparticle velocity control and microparticle sorting.


2018 ◽  
Vol 7 (4.19) ◽  
pp. 818
Author(s):  
Kadhim K. Idan Al-Chlaihawi ◽  
Dhafer A. Hamzah ◽  
Ahmed K. Zarzoor ◽  
Yousif M. Hasan

Promoting reduction of PV temperature plays crucial role in increasing electrical performance. The present work deal with different types of absorber shape for analysing heat transfer phenomena. Serpentine and spiral absorber are using to verify this purpose with different boundary conditions of inlet mass flow rate and inlet temperatures.The recent study was conducted to evaluate the effect of some operating and designing parameters such as solar radiation levels, flow rates, absorber shape and cooling water temperature on the performance of PVT system numerically. Performance of PVT system determined by thermal efficiency, electrical efficiency and the summation of both known as total or PVT efficiency. Solar radiation ranging from 500 W/m2 to1000 W/m2 was introduced and at each, flow rates of water ranging from 0.016 kg/s to 0.05 kg/s. The results show that the performance of PVT increases with a flow rate at all radiation levels. Also the spiral flow absorber gives a higher performance than serpentine absorber where the value of  of spiral absorber is increased by about 5.2% compared to the value of serpentine absorber, on the other hand, the rate of heat loss ( decreased by about 10%.Increasing initial cooling water temperature degrades electrical efficiency of PVT system.  


Author(s):  
E. G. Berestovitskiy ◽  
P. I. Kizilov ◽  
A. N. Kruchkov ◽  
N. V. Pialov

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1022 ◽  
Author(s):  
Xiaohong Liu ◽  
Yuekuan Zhou ◽  
Chun-Qing Li ◽  
Yaolin Lin ◽  
Wei Yang ◽  
...  

This paper investigates the energy performances of a hybrid system composed of a phase change materials-ventilated Trombe wall (PCMs-VTW) and a photovoltaic/thermal panel integrated with phase change material (PV/T-PCM). Equivalent overall output energy (QE) was proposed for energy performance evaluation regarding different energy forms, diversified conversions and hybrid thermal storages. This study focuses on parameters’ optimization of the PV/T-PCM system and parameters in the PCMs-VTW are kept optimal. Based on the experimentally validated numerical modelling, nine trial experiments have been conducted following Taguchi L9 (34) standard orthogonal array. The higher the better concept was implemented and the optimal combination of operating parameters was thereafter identified by using signal-to-noise (S/N) ratio and Analysis of Variance (ANOVA) method. The results show that QE is highly dependent on the mass flow rate, followed by the diameter of active cooling water pipe. However, the inlet cooling water temperature and the thickness of PCM have limited influence on QE. The optimal combination of each factor was identified as B3A3C2D1 (mass flow rate of 1 kg/s, diameter of water pipe of 0.6 m, inlet cooling water temperature of 15 °C and the thickness of PCM of 20 mm) with the highest QE of 20,700 kWh.


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