Discharge Outlet Research Articles

The Influence of Guide Vane to the Performance of Cross-Flow Wind Turbine on Waste Energy Harvesting System

The purpose of this experiment is to know the influence of a single guide vane position and angle to the performance of a cross-flow wind turbine. The cross-flow wind turbine was positioned at the discharge outlet of a cooling tower model to harness the discharged wind for electricity generation. A guide vane was used to enhance the rotational speed of the turbines for power augmentation. Various position and angle of attack of the guide vane were tested in this experiment. To avoid negative impact on the performance of the cooling tower fan and to optimize the wind turbine performance, the turbine position on the discharge wind stream was also studied. The result showed that cross-flow wind turbine with a guide vane attached at the right position had a higher coefficient of power than cross flow turbine without guide vane. A crossflow wind turbine with the guide vane at the position of 150 mm from the center and 30° angles had the highest coefficient of power of 0.49. Comparing to the wind turbine without guide vane, the coefficient of power of the cross-flow wind turbine was increased about 84.3%.

Direct contact membrane distillation for the treatment of industrial dyeing wastewater and characteristic pollutants

Abstract In this work, the feasibility of utilizing direct contact membrane distillation (DCMD) for the treatment of industrial dyeing wastewater and their characteristic pollutants were demonstrated. Two commercial hydrophobic membranes made of polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) were comparatively studied. The results suggest that PTFE membrane always demonstrates enhanced flux and rejection performance for selected characteristic pollutants compared with that of PVDF counterpart, which can be ascribed to its enhanced hydrophobicity and reduced wettability. When challenging the industrial and synthetic dyeing wastewater, the DCMD system demonstrates different performances in terms of flux and rejection efficiency, which are closely related to the sample compositions and concentration. The relevant COD and color removal efficiency over 48 h continuous operation was, respectively, 90% and 94% for sample 1# (from discharge outlet of the dyeing vat wastewater), 96% and 100% for sample 2# (from discharge outlet of the wastewater treatment plant after physicochemical and biological treatment), and 89% and 100% for sample 3# (synthetic dyeing wastewater after bench-scale membrane bioreactor treatment). Furthermore, various advanced characterization techniques were employed to study the fouling properties and performance of the PTFE membrane. The suspended solids accumulation (e.g., SiO2 and dispersed dyes) may be responsible for the membrane wetting and fouling. These overall findings suggest that the DCMD process is a promising option for the treatment of dyeing wastewater with limited energy consumption and high performance.

Calculation of intercepted runoff depth based on stormwater quality and environmental capacity of receiving waters for initial stormwater pollution management.

While point source pollutions have gradually been controlled in recent years, the non-point source pollution problem has become increasingly prominent. The receiving waters are frequently polluted by the initial stormwater from the separate stormwater system and the wastewater from sewage pipes through stormwater pipes. Consequently, calculating the intercepted runoff depth has become a problem that must be resolved immediately for initial stormwater pollution management. The accurate calculation of intercepted runoff depth provides a solid foundation for selecting the appropriate size of intercepting facilities in drainage and interception projects. This study establishes a separate stormwater system for the Yishan Building watershed of Fuzhou City using the InfoWorks Integrated Catchment Management (InfoWorks ICM), which can predict the stormwater flow velocity and the flow of discharge outlet after each rainfall. The intercepted runoff depth is calculated from the stormwater quality and environmental capacity of the receiving waters. The average intercepted runoff depth from six rainfall events is calculated as 4.1mm based on stormwater quality. The average intercepted runoff depth from six rainfall events is calculated as 4.4mm based on the environmental capacity of the receiving waters. The intercepted runoff depth differs when calculated from various aspects. The selection of the intercepted runoff depth depends on the goal of water quality control, the self-purification capacity of the water bodies, and other factors of the region.

FLOW PROPERTIES AND PATTERN FLOW PREDICTION OF FOOD INDUSTRIAL POWDERS

More and more industries are faced with new products that need to be stored in silos which, in general, require knowledge of their physical properties and, above all, flow. Food industries are among those using powders as raw materials likely to develop functional problems. Thus, the aim of the present study was to investigate the flow properties of six food powders using equipment called Powder Flow Tester, and the results were compared with those recommended by the Eurocode 1 Part 4 international standard. Wide range of variation in the flow properties responses was observed, suggesting that their expression through a single average value may not be suitable for vertical silos. It was concluded that only the bulk density of products is in accordance with the standard. In relation to flow, only flaked corn is able to flow without possibility of obstruction in the discharge with higher discharge outlet dimensions, being also recommended for flaked oat.

Development of multi-functional combine harvester with grain harvesting and straw baling

The decomposition and burning of straw results in serious environmental pollution, and research is needed to improve strategies for straw collection to reduce pollution. This work presents an integrated design of multi-functional rice combine harvester that allows grain harvesting and straw baling. This multi-functional combine harvester could reduce the energy consumption required for rice harvesting and simplify the process of harvesting and baling. The transmission schematic, matching parameters and the rotation speed of threshing cylinder and square baler were designed and checked. Then the evaluation of grain threshing and straw baling were tested on a transverse threshing cylinders device tes rig and straw square bales compression test rig. The test results indicated that, with a feeding rate of 3.0 kg/s, the remaining straw flow rate at the discharge outlet was only 1.22 kg/s, which indicates a variable mass threshing process by the transverse threshing cylinder. Then the optimal diameter, length and rotating speed of multi-functional combine harvester transverse threshing cylinder were 554 mm, 1590 mm, and 850 r/min, respectively. The straw bale compression rotating speed of crank compression slider and piston was 95 r/min. Field trials by the multi-functional combine harvester formed bales with height×width×length of 40×50×54-63 cm, bale mass of 22.5 to 26.0 kg and bale density 206 to 216 kg/m3. This multi-functional combine harvester could be used for stem crops (such as rice, wheat and soybean) grain harvesting and straw square baling, which could reduce labor cost and power consumption.

Optimization of Ventilation and Alarm Setting During the Process of Ammonia Leak in Refrigeration Machinery Room Based on Numerical Simulation

In order to optimize the ventilation effect of ammonia leakage in the refrigeration machinery room, a food processing enterprise is selected as the subject investigated. The velocity and concentration field distribution during the process of ammonia leakage are discussed through simulation of refrigeration machinery room using CFD software. The ventilation system of the room is optimized in three aspects which are named air distribution, ventilation volume and discharge outlet. The influence of the ammonia alarm system through ventilation is also analyzed. The results show that it will be better to set the discharge outlet at the top of the plant than at the side of the wall, and the smaller of the distance between the air outlet and the ammonia gathering area, the better of the effect of ventilation will be. The air flow can be improved and the vortex flow can be reduced if the ventilation volume, the number of air vents and the exhaust velocity are reasonably arranged. Not only the function of the alarm could be ensured, but also the scope of the detection area could be enlarged if the detectors are set on the ceiling of the refrigeration units or the ammonia storage vessel.

Simulation of the effect of an oil refining project on the water environment using the MIKE 21 model

A case study of the Caofeidian oil refining project is conducted. A two-dimensional convective dispersion mathematical model is established to simulate the increase in the concentration of pollutants resulting from the wastewater discharge from the Caofeidian oil refining project and to analyze the characteristics of the dispersion of pollutants after wastewater is discharged and the effect of the wastewater discharge on the surrounding sea areas. The results demonstrate the following: (1) The Caofeidian sea area has strong tidal currents, which are significantly affected by the terrain. There are significant differences in the tidal current velocity and the direction between the deep-water areas and the shoals. The direction of the tidal currents in the deep-water areas is essentially parallel to the contour lines of the sea areas. Onshore currents and rip currents submerging the shoals are the dominant currents in the shoals. (2) The pollutant concentration field in the offshore areas changes periodically with the movement of the tidal current. The dilution and dispersion of pollutants are affected by the ocean currents in different tidal periods. The turbulent dispersion of pollutants is the most intense when a neap tide ebbs, followed by when a neap tide rises, when a spring tide ebbs and when a spring tide rises. (3) There are relatively good hydrodynamic conditions near the project's wastewater discharge outlet. Wastewater is well diluted after being discharged. Areas with high concentrations of pollutants are concentrated near the wastewater discharge outlet and the offshore areas. These pollutants migrate southwestward with the flood tidal current and northeastward with the ebb tidal current and have no significant impact on the protection targets in the open sea areas and nearby sea areas.

Responses of mesozooplankton communities to different anthropogenic activities in a subtropical semi-enclosed bay

To evaluate the effects of different anthropogenic activities on zooplankton and the pelagic ecosystem, we conducted seasonal cruises in 2010 to assess spatial heterogeneity among the mesozooplankton communities of Xiangshan Bay, a subtropical semi-enclosed bay in China. The evaluation included five different areas: a kelp farm, an oyster farm, a fish farm, the thermal discharge area of a power plant, and an artificial reef, and we aimed to identify whether anthropogenic activities dominated spatial variation in the mesozooplankton communities. The results demonstrated clear spatial heterogeneity among the mesozooplankton communities of the studied areas, dominantly driven by natural hydrographic properties, except in the area near the thermal discharge outlet of the power station. In the outlet area, thermal shock caused by the discharge influenced the mesozooplankton community by decreasing abundance and biomass throughout the four seasons, even causing a shift in the dominant species near the outlet during summer fromAcartia pacificato eurythermal and warm water taxa. Unique features of the mesozooplankton community in the oyster farm may be due to the combined effects of oyster culture and the natural environment in the branch harbour. However, kelp and fish culture, and the construction of an artificial reef did not exert any obvious influence on the mesozooplankton communities up to 2010, probably because of the small scale of the aquaculture and a time lag in the rehabilitation effects of the artificial reef. Thus, our results suggested that the dominant factors influencing spatial variations of mesozooplankton communities in Xiangshan Bay were still the natural hydrographic properties, but the thermal discharge was an anthropogenic activity that changed the pelagic ecosystem, and should be supervised.

Thermal Recirculation Modeling for Power Plants in an Estuarine Environment

Many power plants require large quantities of water for cooling purposes. The water taken from the source water body (e.g., lakes, estuaries, bays and rivers) circulates through the plant and returns to the source through outfall with a higher temperature. For optimal performance of the power plant, the intake inlet and discharge outlet should be meticulously placed so that the heated water will not recirculate back into the power plant. In this study, the Flow module of the Delft3D software is employed to simulate the temperature transport within the study area in three-dimensional and nested format. Model results are used to optimize the location of intake inlets, outfall outlets and diffuser port orientations. The physical processes used in the study are tidal fluctuations, winds, river discharges, salinity and temperature. The subject power plant (power plant parameters presented in this paper are realistic; however, they do not target any specific power plant within the study area) has a nominal capacity of 2600 MW and is planned to be located in Delaware Bay, USA. Existing field measurements are used to calibrate the model in a coupled two-staged fashion for main tidal constituents, currents and water temperature. The sensitivity of the model against various input parameters is tested, and conservative values are selected. The location of the intake is fixed, and the location of the outfall is changed until the thermal impact to the intake is less than 1 °C. Analysis of the results shows that there is a linear logarithmic relation between the excess temperatures at the intake inlet and horizontal eddy diffusivity. The k - ϵ turbulence closure results in higher excess temperature and a more conservative design. Extending the outfall location to the deeper portion of the estuary combined with port orientations reduces the impact by keeping the thermal plume away from the intake inlet and meeting the established criteria. It is concluded that an approximate distance of 1300 m is the optimal location for the power plant outfall outlets. In addition, the diffuser ports should not discharge the heated water toward the intake and have to be oriented away from the line connecting outfall to the intake.

The Construction and Application of a Multipoint Sampling System for Vehicle Exhaust Plumes

ABSTRACTTo study the formation process of secondary organic aerosols (SOA) in a vehicle exhaust plume near the exhaust gas discharge outlet, a new multipoint sampling system was established. The system has five sampling heads and includes a particulate matter multi-channel film sampling system, a CO2/CO analyzer system, a volatile organic compound (VOC) sampling system, a particulate matter real-time analyzer system, and sensor interfaces. The vehicle exhaust near the exhaust nozzle can be sampled at multiple locations simultaneously using the new multipoint sampling system. Additionally, the system can be used to measure and analyze variations in the fine particulate matter, including the carbonaceous and ionic components, and organic compounds in the plume near the exhaust nozzle. This paper introduces the construction and application of the multipoint sampling system. The motor vehicle exhaust multipoint sampling system is reliable and can accurately capture the characteristics of the exhaust plume near the discharge outlet area. Changes in the CO2 concentration were used to determine whether exhaust was accurately collected at the sampling points. The relationship between the dilution rate and distance was calculated on the basis of on-road test results using the following equation: DR = 21.4X1.16. This equation can be used for modeling purposes, especially in comparisons of model results and observations and in the evaluation of dispersion models.

Design, Manufacture and Performance Evaluation of an Effective Dual Operated Groundnut Decorticator with Blower

A manual (hand operated or bicycle paddle) groundnut decorticating machine attached with a blower is designed, manufactured and its performance assessed. The main components of the machine were the frame, hopper, neck feed control gate, shelling drum, shaft running on bearings, a pneumatic type mechanism, concave sieve and a blower. The rest are pulley and sprocket, discharge outlet and belt drive. The assembled angle iron parts were welded together whiles the sheet metal parts were riveted to hold in position. Testing of the decorticating machine was assessed at three different moisture contents of groundnut (0, 5.1 and 9.3%) and three different levels of machine shaft speed (10, 20 and 30 rpm) all at an average feed rate of 25kg/hr. The results revealed that the decorticating machine’s optimum performance was at 20 rpm machine shaft speed with groundnut moisture content of 0% (purely dry), machine cracking efficiency and percentage groundnut fully cracked was 71.2% and 85.3% respectively. There was reduction in machine performance at machine speeds of 10 rpm and 30 rpm with 45.1%, and 49.7% machine cracking efficiency respectively for the same feed gate rate openings. This was because at a speed of 10 rpm, the nuts were partially cracked (41.6%) and that of 30 rpm and cracked (39.3%), the quantum of groundnut losses through the blower increased considerably leading to a reduction in the quantity of groundnut collected.

Improving drowned drainage outlets with submerged orifices

Drowned outlets are common in riverine areas and sometimes unavoidable. Due to site restrictions, drainage discharge outlets are often submerged as the water level fluctuates during high tides or during the monsoon. As the runoff cannot be discharged through the outlet the drainage system fills up faster, leading to flash floods caused by overspill from the drains. This study is focused on the application of an on-site detention system with submerged orifice to improve the runoff delay from a drowned outlet. The application was investigated through a reduced-scale laboratory set up and then visualized with computational fluid dynamics simulations. The model was tested under different perpendicular flow velocities to analyze the workability and flow characteristics of the submerged orifice. The study showed that, with different headwater and tailwater levels, the energy level can be restored upstream of the orifice and ensure full flow of water from the submerged orifice even when hindered by perpendicular tailwater flow. Besides, the orifice jet's pattern changes with high velocity tailwater flow, although it does not slow down the discharge rate.

Research of flow parameters in a blow off of a hydraulic installation

The paper deals with conditions and parameters of water flow in a blowoff of a hydraulic installation and adjacent area of a discharge channel. The authors point out the significant impact of forms and geometric sizes of outlet structures, as well as stilling structures on the linkage parameters of outlet water flow. The article presents results of research of the impact of a baffle on the water flow in discharge outlet and outlet canal and shows a possibility of hydraulic conditions improvement in discharge canal due to water-diverting wall construction. The authors conclude that deletion of a water-diverting wall in an outlet section of discharge outlet should be proved by technical and economic estimation.

Results of Survey of Reinforced Concrete Structures of Drainage Gallery in Earh-fill Dam

The earth-fill dam of Zhiguli Hydropower Plant is located between the building of the hydropower plant and the concrete spillway dam. To collect seepage water in the body of the earth-fill dam throughout its entire length, inside a stone toe drain, there is a gallery made of reinforced concrete. In order to estimate the technical state, signs of structural deformation, cracks, chips and corrosive wear, a survey of the reinforced concrete structures of the drainage gallery with discharge outlets in the earth-fill dam has been conducted, the main results of which are presented in this paper.As a result of this survey, the areas and the value of subsidence of the reinforced concrete structures of the drainage gallery have been identified. The slope of the drainage gallery and the amount of sediment in it has been defined. Besides, the area along the route of discharge outlets has been examined, and the state of the coastline has been evaluated. Basing on the results of this survey, a detailed assessment of the technical state of the reinforced concrete structures of the drainage gallery in the earth-fill dam of Zhiguli Hydropower Plant has been given.

Development and testing of a motorized cassava fufu pounding machine

A motorized cassava fufu pounding machine was developed and tested. The machine principal parts were hopper, throat, pounding compartment, discharge outlet, main frame, electric motor seat, auger, shaft and pulleys. Mild steel material and stainless steel sheet were used in the fabrication based on its availability, strength, appearance, cost, and corrosion resistance. The machine is powered by a 5hp electric motor; the dimension of the machine is 1010mm × 600mm × 930mm (length × breadth × height). Output capacity of 120kg/hr was obtained. The machine is affordable and easy to operate and manage. It is therefore recommended for the restaurants, chop bars and households to prepare a good and hygienic fufu thereby solving the problem of energy sapping and time wasting in manual fufu pounding.

Distributed subglacial discharge drives significant submarine melt at a Greenland tidewater glacier

AbstractSubmarine melt can account for substantial mass loss at tidewater glacier termini. However, the processes controlling submarine melt are poorly understood due to limited observations of submarine termini. Here at a tidewater glacier in central West Greenland, we identify subglacial discharge outlets and infer submarine melt across the terminus using direct observations of the submarine terminus face. We find extensive melting associated with small discharge outlets. While the majority of discharge is routed to a single, large channel, outlets not fed by large tributaries drive submarine melt rates in excess of 3.0 m d−1 and account for 85% of total estimated melt across the terminus. Nearly the entire terminus is undercut, which may intersect surface crevasses and promote calving. Severe undercutting constricts buoyant outflow plumes and may amplify melt. The observed morphology and melt distribution motivate more realistic treatments of terminus shape and subglacial discharge in submarine melt models.

Spatial and temporal variability of odorous VOC in a food waste treatment plant using hydrothermal hydrolysis and aerobic fermentation technology

Offensive odorant emissions from a food waste (FW) treatment plant that uses hydrothermal hydrolysis and aerobic fermentation technology were studied for 1 month through in situ monitoring and laboratory testing. Results showed that the emission flux (7000 μg kg−1FW h−1) of total volatile organic compounds and concentrations of most volatile organic compounds (VOCs) were highest at the discharge outlet of the hydrothermal hydrolysis reactor. Furthermore, VOC composition analysis showed that the concentrations of most hydrocarbons detected during the sorting/crushing process were higher than those in the aerobic fermentation process, but more oxygenated organic compounds and pinenes were released in the aerobic treatment process. The analysis of VOC temporal characteristics via t test indicated that even with various FW loads during the day and night, most VOC concentrations sampled in the storing room were not significantly different. However, great variances among most VOC concentrations were observed during the sorting/crushing process and at the hydrothermal hydrolysis reactor. The annoyance degrees of offensive gases were also determined via analysis of odor indices. The results suggested that sulfocompounds mainly dominated in terms of high odor activate values during the sorting/crushing process, and the fractional content of oxygenated organic compounds increased in the aerobic treatment processes.

Design and Experimental Analysis of an Exhaust Air Energy Recovery Wind Turbine Generator

A vertical axis wind turbine (VAWT) was positioned at the discharge outlet of a cooling tower electricity generator. To avoid a negative impact on the performance of the cooling tower and to optimize the turbine performance, the determination of the VAWT position in the discharge wind stream was conducted by experiment. The preferable VAWT position is where the higher wind velocity matches the positive torque area of the turbine rotation. With the proper matching among the VAWT configurations (blade number, airfoil type, operating tip-speed-ratio, etc.) and exhaust air profile, the turbine system was not only able to recover the wasted kinetic energy, it also reduced the fan motor power consumption by 4.5% and increased the cooling tower intake air flow-rate by 11%. The VAWT had a free running rotational speed of 479 rpm, power coefficient of 10.6%, and tip-speed-ratio of 1.88. The double multiple stream tube theory was used to explain the VAWT behavior in the non-uniform wind stream. For the actual size of a cooling tower with a 2.4 m outlet diameter and powered by a 7.5 kW fan motor, it was estimated that a system with two VAWTs (side-by-side) can generate 1 kW of power which is equivalent to 13% of energy recovery.

옥내소화전 방수구에 부착되는 감압오리피스의 감압성능에 관한 연구

Indoor hydrant facilities are used to fight initial fires before more intense fire extinguishing activities. Fire extinguishing facilities should ensure good fire extinguishing performance and the safety of users. Indoor hydrant facilities are mostly installed in buildings and facilities, and users must manipulate valves, hoses, and nozzles manually. When the discharge pressure is higher than 0.70 MPa, there is a high possibility that problems with manipulation and hose breakdown can occur. To prevent these problems, a method to attach orifice-type decompression valves to the angle valves of indoor hydrant discharge outlets has frequently been used for decompression methods. However, the decompression performance was reduced due to structural problems of the decompression valves over time. Accordingly, based on three-stage initial pressures, applicable pressure ranges were selected by measuring the decompression performance according to the diameter of the decompression orifices. Based on the data, stable decompression valve models are proposed. These models have the lowest decrease in decompression performance, regardless of time.

Simulation of springs discharge from a karstic aquifer (Crete, Greece), using limited data

Five major groups of springs and more than ten pumping wells comprise the main discharge outlets of Agyia karstic aquifer (W. Crete, Greece). The mean annual discharge of the springs is 76 × 106 m3, while 12 × 106 m3 of water are pumped annually from Myloniana and Agyia’s well fields for public water supply and irrigation. The area is almost composed of entirely karstified carbonate rocks (limestones with dolomites), and karstic drainage contributes to infiltration and replenishment of the aquifer. The present work studies the groundwater flow system in the region to investigate the impact of intensive exploitation of the aquifer especially during dry periods (low water table conditions). Due to the lack of sufficient hydrogeologic data, a part of the aquifer extending upwards of Agyia springs was chosen for building the conceptual and numerical model. The groundwater flow was simulated by establishing a reproduction of the measured water heads in the field and the springs discharge. The appropriate set of boundary conditions and the repetition of the model’s verification in different dry periods resulted in a sufficiently reliable model. This can be used as a tool to assess different water resource management options during dry periods, when the demand for water is high.