Investigation on the Mechanism of Energy Saving and Efficiency Enhancement for Fluid Ejector

2011 ◽  
Vol 121-126 ◽  
pp. 2804-2808
Author(s):  
Gui Ju Xing ◽  
Zi Huan Li ◽  
Hong Liang Zheng ◽  
Jian Wang ◽  
Fu Sheng Jiang
Keyword(s):  
Theoretical Analysis ◽  
Energy Saving ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Turbulent Energy ◽  
Energy Dissipation Rate ◽  
Rate Variation ◽  
Efficiency Enhancement ◽  
Pumping Power ◽  
Rate Condition

Experiments were implemented on a prototype commercial liquid ejector to measure its hydraulic efficiency and the change of which along with a certain range of water flow rate variation was also recorded. Based on theoretical analysis and numerical simulation methods, we improved the ejector’s structure by modifying the suction part of it. Four ameliorated ejector structures, with increased pumping power and reduced flow resistance compared to the prototype, are proposed. Under the same working flow rate condition, flow field computations were conducted on the prototype and the four improved structures. The computational results show that the pumping power increases by 75.97%, the drag coefficient reduces 0.0908, the maximum turbulent energy dissipation rate decreases by 38.88% and the absolute value of the efficiency increases by 13.66%. The work validates the correctness of the theoretical analysis about the mechanism of energy-saving and efficiency enhancement for fluid ejector, and provides a more effective method to improve the performance of liquid ejector.

Analysis of Triangular Microchannel Under Forced Convection Heat Transfer Condition for Laminar Flow Condition

2013 ◽  
Author(s):  
D. A. Kamble ◽  
B. S. Gawali
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Water Flow ◽  
Flow Rate ◽  
Heat Input ◽  
Water Flow Rate ◽  
Temperature Drop ◽  
Experimental Result ◽  
Rate Condition ◽  
Wide Range

Micro-convection is a strategic area in transport phenomena, since it is the basis for a wide range of miniaturized high-performance heat transfer applications. Surface area is one of the important parameter for high flux heat transfer in microchannel performance. This experimental study deals with heat transfer using triangular microchannel having hydraulic diameters of 321μm and 289μm. Experimentation is carried out for triangular microchannel set for different heat input and flow rate condition. Triangular microchannel are manufactured with EDM technology. Testing of microchannel under laminar flow is considered with different tip angle, spacing, and length of microchannels. The different microchannels made up of copper material with 29 microchannel each having three different sets of length of 50 mm, 70 mm and 90 mm respectively. Tip angles for triangular microchannel is varied 50 ° and 60 ° with width of 30 mm each respectively are analyzed numerically. Spacing between triangular microchannels is also varied and 300μm and 400μm are considered for the analysis. Water flow rate is considered laminar flow. The flow rate of water is varied from 0.0167 kg/sec to 0.167 kg/sce to carry away heat. It is observed that as hydraulic diameters increase the heat transfer coefficient decreases. As the heat input to microchannel increases from 10 Watt to 100 Watt the temperature drop across varies from 2° C to 22°C as water flow rate increases. The numerical analysis is done using computer C programming. Experimental result differ from theoretical for temperature drop with variation of 2°C to 5°C. It is also observed that in all triangular microchannels its geometry i.e. tip angle and hydraulic diameter are dominant parameters which influences on rate of heat transfer. With increasing channel depth, increases flow passage area therefore enhances heat transfer sufficiently. From experimentation a Nu number correlation is proposed with considering tip angle, length, spacing of microchannel and other related parameters.

COMPARISON OF OPTIONS FOR THE HEAT DISTRIBUTION NETWORK OF THE RESIDENTIAL NEIGHBORHOOD

2021 ◽  
pp. 17-25
Author(s):  
O. Aleksakhin ◽  
S. Yena ◽  
O. Hordiienko ◽  
V. Novikov ◽  
D. Tsemokh
Keyword(s):  
Flow Rate ◽  
Distribution Network ◽  
Water Flow Rate ◽  
Heating System ◽  
Heat Losses ◽  
Rate Variation ◽  
Outdoor Air ◽  
Heat Network ◽  
Residential Neighborhood ◽  
Medium Flow

The comparison of heat losses by pipelines of an extensive residential neighborhood heating system for two options of the distribution network was carried out for a residential neighborhood in Kharkov. The proposed configuration of the heating network differs from the existing ("basic") one in using of the law of heating medium flow rate variation along the heat pipe length. This law takes into account increased flow rate of heating water through branches at the initial sections of the pipeline. The actual flow rate distribution is approximated by a step function. The difference in the laws of flow rate variation is taken into account by the exponent value. The calculation of heat losses was carried out for underground pipelining in non-accessible tunnels. The temperature of heat line water is taken to be the corresponding to the design outdoor air temperature for heating according to the temperature schedule of the heating network. Specific heat losses by pipelines in heat network sections are considered to be at the standard level for non-accessible tunnels. The soil temperature at the depth of the heat pipe axis is taken equal to 5°C. Heat losses by the structural elements of the heat network are taken into account by a factor of 1.15. The variation of the flow rate and temperature of network water in rated pipeline sections is considered in the analysis.  The water flow rate at the sections was found based on the design thermal loads of connected buildings. It is shown that when choosing the configuration of the distribution network of the heating system of a group of buildings, preference should be given to the option with a lower value of the exponent in the equation for heating medium flow rate variation along the length of the main line of the network. For extensive heating networks, this can be achieved by connecting as many buildings as possible to the heating network sections close to a heat supply station. An increase in the network water flow rate through the branches at the initial sections of the pipeline ensures a decrease in heat losses by the network pipelines. For the considered part of a residential neighborhood, the decrease in heat loss at the design outdoor air temperature for heating is 5.5 %.

scholarly journals A Non-Intrusive Signal-Based Fault Diagnosis Method for Proton Exchange Membrane Water Electrolyzer Using Empirical Mode Decomposition

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4458
Author(s):  
Farid Aubras ◽  
Cedric Damour ◽  
Michel Benne ◽  
Sebastien Boulevard ◽  
Miloud Bessafi ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Empirical Mode Decomposition ◽  
Flow Rate ◽  
Proton Exchange Membrane ◽  
Water Flow Rate ◽  
Proton Exchange ◽  
Rate Variation ◽  
Mode Decomposition ◽  
Exchange Membrane ◽  
The Impact

This work focuses on a signal-based diagnosis approach dedicated to proton exchange membrane water electrolyzer (PEM WE) anode pump fault. The PEM WE cell measurements are performed with an experimental test bench to highlight the impact of water flow rate in the anode compartment. This approach is non-intrusive, and it can detect anode flow rate variation during the electrolysis and is designed to fulfill online diagnosis requirements. Contrary to electrochemical impedance spectroscopy-based approaches (EIS), this method stands out from existing procedures as a result of its few requirements, excluding any signal with perturbing amplitude. Therefore, the electrolyzer remains continuously available, even while the analysis is performed. The empirical mode decomposition (EMD) is used to decompose the signal variation into a sum of amplitude modulation and frequency modulation (AM-FM) components, called intrinsic mode functions (IMFs). In this work, the PEM WE current signal is decomposed into several IMFs using EMD. Then, the energetic contribution of each IMF is calculated. Experimental results exhibited that the energetic contribution of IMFs can be used as relevant criteria for fault diagnosis in PEM WE systems. This process only requires monitoring of the PEM WE current and has a low computational cost, which is a significant economic and technical advantage.

scholarly journals EFFECT OF FLOW STEERING ANGLE TOWARD THE HYDROKINETIC TURBINE PERFORMANCE

2019 ◽  
Vol 3 ◽  
pp. 20-31
Author(s):  
Rudy Soenoko ◽  
Hastono Wijaya
Keyword(s):  
Kinetic Energy ◽  
Water Flow ◽  
Flow Rate ◽  
Turbine Blades ◽  
Water Flow Rate ◽  
Rate Variation ◽  
Steering Angle ◽  
Turbine Performance ◽  
Hydrokinetic Turbine ◽  
Turbine Runner

The kinetic turbine is one of the solutions for use in low-speed river flows ranging from 0.01–2.8 m/s. This kinetic turbine is used as a conversion equipment to convert the water kinetic energy into an electrical energy. The working principle of a kinetic turbine is utilizing and relies on the water kinetic energy. Water flowing into the turbine area will produce a momentum on the turbine blades. This momentum change would then push the turbine blades and finally spin the turbine runner. The aim of research is thedetermination of the effect of water flow steering angle (a) and water flow rate variation in the kinetic turbine performance. This research uses vertical axis kinetic turbines with eight curve blade attached to the turbine runner. The variables used are two values of water flow steering angle, namely 25°and 35°. The water flow rate variation of 30 m3/h, 35 m3/h, 40 m3/h and 45 m3/h. The method used in this study uses a real experimental method. These two variations would then compare with the result of a hydrokinetic turbine performance done on the previous research. The results show that the water flow steering angle a affected the kinetic turbine performance (power, efficiency and torque). From these several water flow steering angle and water flow rate variations, the turbine performance with a 35° water flow steering angle get the highest performance compared with the use of 25° and 14° water flow steering angle. The greater the flow angle and the greater the water flow rate, the greater the torque, power and efficiency. The highest turbine power produced, P=17.5 W, occurs on the 35° water steering angle, and on a Q=45 m3/h water flow rate and on a 80 rpm turbine rotation. While the highest turbine efficiency, h=27 %, occurred on the Q=30 m3/h water flow rate, on a 60 rpm turbine rotation and on a water flow steering angle a=35°. The highest turbine torque, 3.1 Nm, occurs at Q=45 m3/h water flow rate at a maximum turbine braking and on a water steering angle a=35°.

scholarly journals Performance of Solar Absorption-Subcooled Compression Hybrid Cooling System for Different Flow Rates of Hot Water

2020 ◽  
Vol 10 (3) ◽  
pp. 810 ◽  
Author(s):  
Jinfang Zhang ◽  
Zeyu Li ◽  
Yue Jing ◽  
Yongrui Xu
Keyword(s):  
Energy Saving ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling System ◽  
Water Flow Rate ◽  
Hot Water ◽  
Solar Absorption ◽  
Flow Rates ◽  
High Rise ◽  
Daily Energy

The solar absorption-subcooled compression hybrid cooling system (SASCHCS) is tech-economically feasible for high-rise buildings. Since such a system operates with no auxiliary heat source, the performance coupling of its absorption subsystem and solar collectors is sensitive to the variation of hot water flow rate. In this regard, the relationship of system performance and hot water flow rate is required to be clarified exactly. Therefore, this paper aims to illustrate the effect mechanism of hot water flow rate and to propose the corresponding decision criterion. The case study is based on a typical high-rise office building in subtropical Guangzhou. The daily working process of this system with different hot water flow rates is simulated and analyzed. Subsequently, the useful heat of collectors and cooling capacity of the absorption subsystem with the hot water flow rate is discussed in detail. The results show that the SASCHCS operates with hot water temperatures ranging from 60 °C to 90 °C. The energy saving increases with the rise of hot water flow rate, but such variation tends to be flat for the excessively high flow rate. As the collector flow rate increases from 1 m3/h to 10 m3/h, the daily energy saving improves by 21% in August. Similarly, the daily energy saving increases by 37.5% as generator hot water flow rate increases from 1 m3/h to 10 m3/h. In addition, the collector flow rate of 3.6 m3/h (13.33 (kg/m2 h)) and the generator flow rate of 5.2 m3/h (19.26 (kg/m2 h)) are optimal for the annual operation, with considering power consumption of water pumps. This paper is helpful for the improvement of SASCHCS operating performance.

CFD Analysis on the Flat Runner Blades of Propeller’s Turbine under Low Head and Low Flow Condition

2014 ◽  
Vol 699 ◽  
pp. 437-442 ◽  
Author(s):  
Masjuri Musa Othman ◽  
Juhari Ab Razak ◽  
Mohd Farriz Bashar ◽  
Nor Salim Muhammad ◽  
Kamaruzzaman Sopian
Keyword(s):  
Flow Rate ◽  
Rural Areas ◽  
Fluid Dynamic ◽  
Water Flow Rate ◽  
Low Flow ◽  
Rate Condition ◽  
Low Head ◽  
Do It Yourself ◽  
Flat Profile ◽  
User Friendly

Hydropower is one of the most widely source to produce electricity for domestic houses as well as for industries around the world. However, for those off-grid settlements the pico-hydro scheme is more suitable due to its cost-effectiveness (less maintenance), clean, user-friendly and do not involved with huge construction works. Even the installation of this type of hydropower scheme is very simple as do it yourself (DIY) concept. One of the most popular pico-hydro turbines which have been implemented widely in rural areas until nowadays is propeller type or also known as axial turbine. Propeller turbine is selected because it is suitable to operate under low head with high flow rate condition. However, in this particular case, low head with low flow rate of water are the two main parameters which need to be considered. This is because during dry or drought season the water level of the rivers will become low and fluctuated, and this scenario affected the performance of the propeller turbine itself. In order to overcome this problem, the runner blades of the propeller turbine need to be redesigned to suit with this nature behavior. Therefore, in this study the runner blades with flat profile with few different angles and number of blades will be applied under 2 meters head. On the other hand, since the low flow is another parameter which needs to be focused therefore the value of the water flow rate has been set to 13 l/s. Analysis tools such as Computer Fluid Dynamic (CFD) is applied in this study in order to determine the most optimum results based from few selected parameters which has been mentioned. From the CFD’s final result, 3 blades with angle 300 was the best combination among the parameters involved.

scholarly journals Experimental Study on Thermal Radiation Attenuation Using Water Mist of Twin-fluid Atomizer

2021 ◽  
Vol 35 (4) ◽  
pp. 24-32
Author(s):  
Jae Geun Jo ◽  
Chi Young Lee
Keyword(s):  
Thermal Radiation ◽  
Water Flow ◽  
Flow Rate ◽  
Air Flow ◽  
Water Flow Rate ◽  
Water Mist ◽  
Air Flow Rate ◽  
Radiation Attenuation ◽  
Rate Condition ◽  
Flow Rates

In this study, the thermal radiation attenuation performance of water mist was investigated using twin-fluid atomizers. The water and air flow rates of Small atomizer were 36~105 g/min and 10~30 L/min, whereas those of Large atomizer were 37~300 g/min and 20~60 L/min, respectively. In the present experimental range, the thermal radiation attenuation of Small atomizer and Large atomizer were 6.1~11.9% and 5.2~14.6%, respectively. With the increase in water and air flow rates, the thermal radiation attenuation increased, and under similar water and air flow rate conditions, Small atomizer showed higher thermal radiation attenuation than Large atomizer. Based on the present experimental data, it was found that the air (gas) discharge area is a potentially important factor in determining the thermal radiation attenuation performance. Additionally, through the analysis of thermal radiation attenuation per unit water flow rate, it was confirmed that the twin-fluid atomizer can result in higher thermal radiation attenuation than the single-fluid atomizer under the same water flow rate condition.

scholarly journals Energy Saving Approach for an Electric Pump Using a Fuzzy Controller

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3330
Author(s):  
Tuchapong Suwongsa ◽  
Kongpol Areerak ◽  
Kongpan Areerak ◽  
Jakkrit Pakdeeto
Keyword(s):  
Energy Saving ◽  
Induction Motor ◽  
Flow Rate ◽  
Power Factor ◽  
Fuzzy Controller ◽  
Search Algorithm ◽  
Water Flow Rate ◽  
Input Power ◽  
Experimental Results ◽  
Electric Pump

This paper presents an energy-saving approach for electric pumps widely used in agriculture. A capacitor-run single-phase induction motor is used with a centrifugal pump. An appropriate energy-saving frequency and voltage calculation algorithm is proposed in this paper. The fuzzy controller is used to control the water flow rate of the electric pump. Moreover, the adaptive Tabu search algorithm is used to identify induction motor parameters. The experimental results from the energy-saving approach are compared with the valve control and V/f control in terms of input power and power factor. From the experimental results, the electric pump using the proposed energy-saving approach consumes minimum input power compared with other approaches. In addition, the energy-saving approach can provide a good power factor at any flow rate.

Sign in / Sign up

Export Citation Format

Share Document