scholarly journals The Optimal Pumping Power under Different Ice Slurry Concentrations Using Evolutionary Strategy Algorithms

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6738
Author(s):  
Shuai Hao ◽  
Wenjie Zhou ◽  
Junliang Lu ◽  
Jiajun Wang

A suitable ice slurry fluid with a suitable ice concentration ratio can save operational costs. The design of the optimal ice slurry concentration focuses on finding an evolution strategy, which can further minimize the power consumption of the pump. A theoretical model was established to simulate the effect of different ice concentrations and flow rates on the performance of the pump. The data obtained were fitted by curve-fitting function. The process was modeled in the MATLAB evolutionary strategy algorithm to obtain the configuration scheme of the ice concentration and flow under different refrigeration capacities. The simulation results showed that when the required cooling capacity was 13.889 kWh, ice concentration was set to 19.68%, and flow rate was set to 2.1075 × 10−4 m3/s, the power consumption could be reduced by 23%.

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 555
Author(s):  
Sangkyung Na ◽  
Sanghun Song ◽  
Seunghyuk Lee ◽  
Jehwan Lee ◽  
Hyun Kim ◽  
...  

In this study, evaporator optimization, via both experimental and simulation methods was conducted. To evaluate the evaporator performance, under the optimal system, the compressor operating time and the effects of oil on the refrigerator system were studied. If the temperature of the refrigerator chamber reaches the setting value, the compressor stops working and it leads to the temperature of the refrigerator chamber slowly increasing, due to the heat transfer to the ambient. When the refrigerator temperature is out of the setting range, the compressor works again, and the refrigerator repeats this process until the end of its life. These on/off period can be controlled through the compressor piston movement. To determine the optimal compressor operating conditions, experiments of monthly power consumption were conducted under various compressor working times and the lowest power consumption conditions was determined when the compressor worked continuously. Lubricating oil, the refrigerator system, using oil, also influenced the system performance. To evaluate the effect of oil, oil eliminated and oil systems were compared based on cooling capacity and power consumption. The cooling capacity of the oil eliminated system was 2.6% higher and the power consumption was 3.6% lower than that of the oil system. After determining the optimal operating conditions of the refrigerator system, visualization experiments and simulations were conducted to decide the optimal evaporator and the conventional evaporator size can be reduced by approximately 2.9%.


2020 ◽  
Vol 11 (1) ◽  
pp. 129
Author(s):  
Po-Yu Kuo ◽  
Ming-Hwa Sheu ◽  
Chang-Ming Tsai ◽  
Ming-Yan Tsai ◽  
Jin-Fa Lin

The conventional shift register consists of master and slave (MS) latches with each latch receiving the data from the previous stage. Therefore, the same data are stored in two latches separately. It leads to consuming more electrical power and occupying more layout area, which is not satisfactory to most circuit designers. To solve this issue, a novel cross-latch shift register (CLSR) scheme is proposed. It significantly reduced the number of transistors needed for a 256-bit shifter register by 48.33% as compared with the conventional MS latch design. To further verify its functions, this CLSR was implemented by using TSMC 40 nm CMOS process standard technology. The simulation results reveal that the proposed CLSR reduced the average power consumption by 36%, cut the leakage power by 60.53%, and eliminated layout area by 34.76% at a supply voltage of 0.9 V with an operating frequency of 250 MHz, as compared with the MS latch.


2002 ◽  
Vol 11 (01) ◽  
pp. 51-55
Author(s):  
ROBERT C. CHANG ◽  
L.-C. HSU ◽  
M.-C. SUN

A novel low-power and high-speed D flip-flop is presented in this letter. The flip-flop consists of a single low-power latch, which is controlled by a positive narrow pulse. Hence, fewer transistors are used and lower power consumption is achieved. HSPICE simulation results show that power dissipation of the proposed D flip-flop has been reduced up to 76%. The operating frequency of the flip-flop is also greatly increased.


Author(s):  
Angela Gerlach ◽  
Dorian Perlitz ◽  
Flemming Lykholt-Ustrup ◽  
Christian Brix Jacobsen ◽  
Paul Uwe Thamsen

This paper analyzes the clogging behavior of a vortex pump with different impeller designs. The influence of blade outlet angle, blade number, and impeller diameter were tested. Non-woven textiles in different concentrations served as the clogging material. The results suggest that a smaller outlet blade angle, a higher blade number, and a larger impeller diameter allow pumping more textiles. Impellers that were capable of pumping more textiles, however, were less efficient. Overall, pumping textiles causes efficiency losses. However, this could not be only related to increased power consumption. Flow rates under clogging operation were close to the flow rates under clear water operation irrespective of the amount of clogging material and the impellers design. Further, in all tests clogging material accumulated at the suction mouth in the casing.


Author(s):  
Arzu Özbey ◽  
Mehrdad Karimzadehkhouei ◽  
Evrim Kurtoğlu ◽  
Ali Koşar

Magnetic actuation of ferrofluids with dynamic magnetic fields is one of the most promising research areas with its wide and different potential application areas such as biomedical and micropumping applications. Ferrofluid has the potential of opening up new possibilities. To have more understanding about various fields of engineering, more research should be conducted by considering both the experimental and modeling aspects. The most important parameters determining the flow property, flow rates and overall system efficiency are the quality and the topology of magnetic fields used in these systems. Therefore, the methods of dynamic magnetic field generation constitute a central problem to obtain desired performance. This study includes modeling and simulation of ferrofluid actuation with dynamic magnetic fields by using the COMSOL software and reports that ferrofluid actuation can be successfully used and the simulation results agree well with the experimental results.


Author(s):  
Pardeep Shahi ◽  
Apurv Deshmukh ◽  
Hardik Hurnekar ◽  
Satyam Saini ◽  
Pratik V Bansode ◽  
...  

Abstract Transistor density trends till recently have been following Moore's law, doubling every generation resulting in increased power density. The computational performance gains with the breakdown of Moore's law were achieved by using multi-core processors, leading to non-uniform power distribution and localized high temperatures making thermal management even more challenging. Cold plate-based liquid cooling has proven to be one of the most efficient technologies in overcoming these thermal management issues. Traditional liquid-cooled data center deployments provide a constant flow rate to servers irrespective of the workload, leading to excessive consumption of coolant pumping power. Therefore, a further enhancement in the efficiency of implementation of liquid cooling in data centers is possible. The present investigation proposes the implementation of dynamic cooling using an active flow control device to regulate the coolant flow rates at the server level. This device can aid in pumping power savings by controlling the flow rates based on server utilization. The FCD design contains a V-cut ball valve connected to a micro servo motor used for varying the device valve angle. The valve position was varied to change the flow rate through the valve by servo motor actuation based on pre-decided rotational angles. The device operation was characterized by quantifying the flow rates and pressure drop across the device by changing the valve position using both CFD and experiments. The proposed FCD was able to vary the flow rate between 0.09 lpm to 4 lpm at different valve positions.


Author(s):  
Dr. Mazhar Hussain

The hydrodynamic characteristics of mixing fluids are always the points to consider in improvement of their mixing quality especially using motionless mixers normally stated as “Static Mixers”. Motionless mixing technique was adopted for Air-Water system with the advantage of negligible power consumption over dynamic mixers. Different hydrodynamic characteristics were experimented using “Baffle Type” static element and were compared to those of already used in recent studies. Dissolved oxygen content, Static mixer geometry (i.e. Baffle, Blade, Wheel, Plate and Needle), mixing fluids flow rates were chosen as variables and selected in this content as rate of mass transfer study which founds out to be significant using “Baffle Type” static element. Volumetric mass transfer was also achieved at higher scale which gives a clear indication of increase the mass transfer coefficient in between the comparison of “Baffle type” element and other mentioned elements. Pressure droplet and depletion in Air bubble size across static elements were visually perceived using Hg-Manometer and still photography respectively. A mathematical model was also developed portraying the Air bubble diameter at different flow rates for this system. Other hydrodynamics like higher Dissolved Oxygen (DO) Content, Less Power consumption were also found to be more advantageous for “Baffle Type” static element.


2019 ◽  
Vol 8 (2) ◽  
pp. 6527-6534

Massive Multi-Input and Multi-Output (MIMO) antenna system potentially provides a promising solution to improve energy efficiency (EE) for 5G wireless systems. The aim of this paper is to enhance EE and its limiting factors are explored. The maximum EE of 48 Mbit/Joule was achieved with 15 user terminal (UT)s. This problem is related to the uplink spectral efficiency with upper bound for future wireless networks. The maximal EE is obtained by optimizing a number of base station (BS) antennas, pilot reuse factor, and BSs density. We presented a power consumption model by deriving Shannon capacity calculations with closed-form expressions. The simulation result highlights the EE maximization with optimizing variables of circuit power consumption, hardware impairments, and path-loss exponent. Small cells achieve high EE and saturate to a constant value with BSs density. The MRC scheme achieves maximum EE of 36 Mbit/Joule with 12 UTs. The simulation results show that peak EE is obtained by deploying massive BS antennas, where the interference and pilot contamination are mitigated by coherent processing. The simulation results were implemented by using MATLAB 2018b.


1973 ◽  
Vol 15 (5) ◽  
pp. 382-386 ◽  
Author(s):  
E. M. Smith

Thermal performances of several cross-inclined in-line tube banks in crossflow are compared with parallel in-line and parallel staggered tube banks of similar geometry, and found to be superior at higher flow rates.


2019 ◽  
Vol 30 ◽  
pp. 01006
Author(s):  
Alexander Kozhemyakin ◽  
Ivan Kravchenko

The paper presents design flow and simulation results of the W-band fundamental voltage-controlled oscillator in 0.13 μm SiGe BiCMOS technology for an automotive radar application. Oscillator provides fundamental oscillation range of 76.8 GHz to 81.2 GHz. According to simulation results phase noise is –89.3 dBc/Hz at 1 MHz offset, output power is –5.6 dBm and power consumption is 39 mW from 3.3 V source.


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