scholarly journals Influence of Plate Orifice in the Pre-Mixing of Gas-Powered Water Heaters

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 17
Author(s):  
Roberto Magalhães ◽  
Senhorinha Teixeira ◽  
Manuel Ferreira ◽  
José Teixeira
Keyword(s):  
Pressure Drop ◽  
Hot Water ◽  
Pollutant Emission ◽  
Heat Output ◽  
Liquefied Petroleum Gas ◽  
Water Heater ◽  
Water Stream ◽  
Flame Instability ◽  
Air Supply ◽  
Safety Features

Amongst the various alternatives for hot water production for domestic use, instantaneous heaters are still widely used in many markets such as the Portuguese market. In this system, a gas boiler converts the chemical energy of the gas (Liquefied Petroleum Gas, Natural Gas) to a water stream, as it is used. The complexity of such devices ranges from those with a natural convection to those with full pre-mixing of the air-fuel. The tightening of the legislation targeting these appliances is promoting an increase in efficiency, pollutant emission reduction and an increase in the safety features. The purpose of this work was to test the thermal performance of a water heater prototype with 22 kW of nominal heat output, running on Propane. Changes were made to the plate with orifices that limit the air supply to the burner flutes, where the pre-mixture with the fuel is partially made. Four different plates with different orifice diameters were built and tested in real case scenarios, taking into special consideration the pollutant emission and the fuel consumption verified. From the results, it was concluded that the best configuration in terms of efficiency is the original one, followed by the “−0.5 mm” and “−1 mm” plates. On the other hand, the best plate in terms of CO emission was the “−1 mm” plate. Concerning the plates with larger diameters to the manufacturer’s original configuration, flame instability was verified as a result of the greater primary airflow. Under the same test conditions, it was noted that the introduction of a nozzle into the fan inlet led to the suction of a larger amount of air. Finally, it was also concluded that the reduction in the orifice diameters of the plates reduces the split of primary air, resulting in an increased pressure drop in the flutes and in the overall pressure drop of the system.

scholarly journals Design and CFD Simulation of Solar Water Heater Used in Solar Assisted Biogas System

2020 ◽  
Vol 9 (3) ◽  
pp. 371-380
Keyword(s):  
Pressure Drop ◽  
Flat Plate ◽  
Temperature Rise ◽  
Economic Benefits ◽  
Hot Water ◽  
Solar Water Heater ◽  
Water Heater ◽  
Solar Water ◽  
Collector Temperature ◽  
Flat Plate Collector

Difficulty in collecting conventional energy sources as well as their economic benefits including saving of time ,money, fertilizer of higher nutrient value, availability of waste easy and comfortable cooking, health benefits including the reduction diseases and environmental benefits such as saving of forest, clear surrounding were the main motivational factors for this research. However, climate temperatures in areas are too low to enable enough biogas production in small unheated digesters to meet the energy requirements of the institute, so the objectives of were to overcome the problem of energy by solar assisted with the hot water storage tank. In this research mathematical modeling of the solar water heater was designed and the analysis of heat transfer coefficient (losses) through the flat plate collector was done and the techniques that used to reduce these losses also mentioned. From the simulation results; the effect of mesh type on flat plate collector, temperature rise, and pressure drop were characterized including flow type in the laminar and turbulent using CFD approach. The FPC was needed for the preparation of the hot water for the heating of the waste food for the selected fixed dome digester with 2m2 was designed. The effect of water mass flow rate 0.01-0.05kg/s on flat plate collector, temperature rise, pressure drop, and velocity was characterized including the variation of flow types intensity using CFD approach. The optimal temperature to this process was 37 °C.The results obtained have been validated with analytical results

Pollutant emission from a heat station supplied with agriculture biomass and wood pellet mixture

2012 ◽  
Vol 33 (2) ◽  
pp. 231-242 ◽  
Author(s):  
Marek Juszczak ◽  
Katarzyna Lossy
Keyword(s):  
Carbon Monoxide ◽  
Pollutant Emission ◽  
Heat Output ◽  
Wood Pellets ◽  
Wood Pellet ◽  
Carbon Monoxide Concentration ◽  
Heat Efficiency ◽  
Air Stream ◽  
Fuel Mixtures ◽  
Lower Carbon

Pollutant emission from a heat station supplied with agriculture biomass and wood pellet mixtureTests for combustion of hay and sunflower husk pellets mixed with wood pellets were performed in a horizontal-feed as well as under-feed (retort) wood pellet furnace installed in boilers with a nominal heat output of 15 and 20 kW, located in a heat station. During the combustion a slagging phenomenon was observed in the furnaces. In order to lower the temperature in the furnace, fuel feeding rate was reduced with unaltered air stream rate. The higher the proportion of wood pellets in the mixture the lower carbon monoxide concentration. The following results of carbon monoxide concentration (in mg/m3presented for 10% O2content in flue gas) for different furnaces and fuel mixtures (proportion in wt%) were obtained: horizontal-feed furnace supplied with hay/wood: 0/100 - 326; 30/70 - 157; 50/50 - 301; 100/0 - 3300; horizontal-feed furnace supplied with sunflower husk/wood: 50/50 - 1062; 67/33 - 1721; 100/0 - 3775; under-feed (retort) furnace supplied with hay/wood: 0/100 - 90; 15/85 - 157; 30/70 - 135; 50/50 - 5179; under-feed furnace supplied with sunflower husk/wood: 67/33 - 2498; 100/0 - 3128. Boiler heat output and heat efficiency was low: 7 to 13 kW and about 55%, respectively, for the boiler with horizontal-feed furnace and 9 to 14 kW and 64%, respectively, for the boiler with under-feed furnace.

The Control of Iron Bacterial Plugging of a Well by Tyndallization Using Hot Water Recycling

1986 ◽  
Vol 21 (1) ◽  
pp. 50-57 ◽  
Author(s):  
D. R. Cullimore ◽  
N. Mansuy
Keyword(s):  
Direct Injection ◽  
Small Diameter ◽  
Hot Water ◽  
Water Recycling ◽  
Water Heater ◽  
Time Intervals ◽  
Flow Rates ◽  
Water Well ◽  
Flow Loss ◽  
The Town

Abstract A small diameter water well drilled in 1977 in the Town of Bulyea, Saskatchewan generated such a rapid plugging (biofouling) that by 1979 the flow rate was reduced by 59%. Heavy growths of non-specific iron bacteria were found in the water and biofouling projected to be the principal cause of the flow loss. Tyndallization (repeated pasteurizations) treatment was applied using a hot water recycling system installed above the well head. Using a displacement passive gravity direct injection of hot water at 82°C from a water heater into the well, a sequential elevation of water column temperatures occurred until bio-film dispersion occurred (pasteurization) at 45°C+. A recovery to original flow specifications was repeatedly obtained at time intervals ranging from 6 to 403 days. Between treatments, a recurrence of biofouling was noted with flow reductions of 0.06 – 0.07 1/min/day frequently being noted. The rate of plugging appeared to be affected by the previous sequence of pasteurization treatments. Tyndallization was found to satisfactorily control iron bacterial biofouling and maintain flow rates.

scholarly journals Influence of Far Infrared TiO2 and Multi-Walled Carbon Nanotubes Coatings on the Performance of a Hot Water Heater

2021 ◽  
Vol 11 (15) ◽  
pp. 7043
Author(s):  
Tun-Ping Teng ◽  
Shang-Pang Yu ◽  
Yeou-Feng Lue ◽  
Qi-Lin Xie ◽  
Hsiang-Kai Hsieh ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Heating Rate ◽  
Heat Insulation ◽  
Far Infrared ◽  
Hot Water ◽  
Insulation Material ◽  
Water Heater ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Insulation Performance

This study selects titanium dioxide (TiO2) and multi-walled carbon nanotubes (MWCNTs) as far-infrared materials (FIRMs), and further adds water-based acrylic coatings to prepare far-infrared coatings (FIRCs). FIRCs are uniformly coated on #304 stainless steel sheets to make the test samples, which are then installed between the shell and insulation material of the hot water heater to measure the influences of various FIRCs on the performance of the hot water heater. The research results show no significant difference in the heating rate or heat insulation performance of the hot water heater with or without FIRCs coating. However, the uniformity of the water temperatures of the test samples is significantly improved with FIRCs. Considering that the uniformity of water temperature will inhibit the heating rate and heat insulation performance of the hot water heater, TiO2-FIRC should provide better performance improvement when applied to the hot water heater in this study. The application of TiO2-FIRC to large-scale hot water heaters with a high aspect ratio will effectively improve the quality of hot water supply in the future.

scholarly journals Parametric optimization of a stamped longitudinal vortex generator inside a circular tube of a solar water heater at low Reynolds numbers

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Felipe A. S. Silva ◽  
Luis Júnior ◽  
José Silva ◽  
Sandilya Kambampati ◽  
Leandro Salviano
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Reynolds Numbers ◽  
Geometric Parameters ◽  
Vortex Generators ◽  
Longitudinal Vortex ◽  
Solar Water Heater ◽  
Water Heater ◽  
Solar Water

AbstractSolar Water Heater (SWH) has low efficiency and the performance of this type of device needs to be improved to provide useful and ecological sources of energy. The passive techniques of augmentation heat transfer are an effective strategy to increase the convective heat transfer coefficient without external equipment. In this way, recent investigations have been done to study the potential applications of different inserts including wire coils, vortex generators, and twisted tapes for several solar thermal applications. However, few researchers have investigated inserts in SWH which is useful in many sectors where the working fluid operates at moderate temperatures. The longitudinal vortex generators (LVG) have been applied to promote heat transfer enhancement with a low/moderate pressure drop penalty. Therefore, the present work investigated optimal geometric parameters of LVG to enhance the heat transfer for a SWH at low Reynolds number and laminar flow, using a 3D periodical numerical simulation based on the Finite Volume Method coupled to the Genetic Algorithm optimization method (NSGA-II). The LVG was stamped over a flat plate inserted inside a smooth tube operating under a typical residential application corresponding to Reynolds numbers of 300, 600, and 900. The geometric parameters of LGV were submitted to the optimization procedure which can find traditional LVG such as rectangular-winglet and delta-winglet or a mix of them. The results showed that the application of LGVs to enhance heat transfer is an effective passive technique. The different optimal shapes of the LVG for all Reynolds numbers evaluated improved more than 50% of heat transfer. The highest augmentation heat transfer of 62% is found for the Reynolds number 900. However, the best thermo-hydraulic efficiency value is found for the Reynolds number of 600 in which the heat transfer intensification represents 55% of the pressure drop penalty.

Solar Water Heater Design for Houses in Arid Zones

2013 ◽  
Author(s):  
Ramses Vega ◽  
Hector E. Campbell ◽  
Juan de Dios Ocampo ◽  
Diego R. Bonilla G.
Keyword(s):  
Solar Collector ◽  
Extreme Temperature ◽  
Hot Water ◽  
Arid Zones ◽  
Water Heater ◽  
Collector System ◽  
End Use ◽  
Flat Plate Solar Collector ◽  
Demand Profile ◽  
Heater Design

This paper shows the simulation and design of a flat plate solar collector system, used to feed hot water to a typical home located in the city of Mexicali, Baja California, México. The system consists of a solar collector, a storage tank, a water pump and accessories and special tools that allow its proper operation. Analyzing the consumption and end use of water in a typical House, a demand profile is established, which combined with the weather information of the region, constitutes the input parameters required for the simulation of the system, which is performed with the software package TRNSYS. Mexicali, due to its location (latitude 32 °, longitude 114 °) and semi-desert condition presents high temperatures in the summer and low in winter, so the design and operation of such systems require special features, not always considered in the conventional ratings. This paper presents methods for simulation and design oriented to optimize the dimensioning and operation of this type of solar heaters in regions with extreme temperature conditions.

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