Optimization of a radiant system for hydrothermal performance using Taguchi and utility concept

Radiant floor panel technology is gaining popularity as an alternative system over conventional heating, ventilation and, air conditioning system (HVAC) to maintain the room temperature for the desired comfort. This research paper aims to optimize the hydrothermal performance of a radiant system by implementing the Taguchi technique and utility concept for cooling and heating mode of operation. Five geometrical and thermal parameters such as pipe diameter, pipe spacing, concrete layer thickness, wall temperature, and inlet and outlet water temperature difference with three levels are chosen as controlling factors to perform optimization. Considering five parameters and three levels, a total of 27 trial runs (L27) are constructed and computed by mathematical calculation. Two different sets of optimum parameters are obtained for maximizing heat flux and minimizing pressure drop. Further, the utility concept is employed to get a single set of parameters to achieve maximum utilization of the radiant system. Taguchi analysis revealed that thermal parameters like temperature difference and wall temperature are the most influential parameters to reach maximum heat transfer and minimum pressure drop followed by geometrical parameters like pipe spacing and diameter for heat flux and pressure drop, respectively. Providing more weightage to heat flux than pressure drop, utility analysis showed 32% and 42% augmentation in heat flux for cooling and heating mode respectively, at the cost of an increase in pressure drop.

The Use of Geographic Information Systems in the Development of a User-Pay Stormwater Utility in the Mimico Creek Watershed

User fee systems are becoming increasingly popular at local levels of government. By shifting the burden from a tax and spend, to user-pay delivery of services, local governments are able to provide and manage local services with greater efficiency and accountability. A stormwater utility concept has been created for dealing with the often-expensive construction, maintenance, upgrading, and management of storm sewers and associated infrastructure. By examining the various user-pay systems for stormwater management, local governments and researchers can make a more informed decision on whether or not it is an appropriate method to raise revenues. The collection of fees is not based on consumption, as in many other public utilities, but on the property owner's contribution to the problem. Therefore, any user-pay stormwater utility must be easily understood and defensible to the general public. As well, the utility creation, administration, and management process can be aided by the use of a Geographic Information System (GIS). Data can be easily collected, stored, and analyzed, as well as be displayed in a way that is easy to understand, not only by the managers and analysts, but by the general public as well.

The Use of Geographic Information Systems in the Development of a User-Pay Stormwater Utility in the Mimico Creek Watershed

User fee systems are becoming increasingly popular at local levels of government. By shifting the burden from a tax and spend, to user-pay delivery of services, local governments are able to provide and manage local services with greater efficiency and accountability. A stormwater utility concept has been created for dealing with the often-expensive construction, maintenance, upgrading, and management of storm sewers and associated infrastructure. By examining the various user-pay systems for stormwater management, local governments and researchers can make a more informed decision on whether or not it is an appropriate method to raise revenues. The collection of fees is not based on consumption, as in many other public utilities, but on the property owner's contribution to the problem. Therefore, any user-pay stormwater utility must be easily understood and defensible to the general public. As well, the utility creation, administration, and management process can be aided by the use of a Geographic Information System (GIS). Data can be easily collected, stored, and analyzed, as well as be displayed in a way that is easy to understand, not only by the managers and analysts, but by the general public as well.

Multi Objective Study on Machining Characteristics of AISI H-11 Tool Steel Prepared by Different Processing Techniques

In the current study, hard turning of AISI H11 tool steel is done using TiAlN coated cutting tool. The workpiece is prepared by three different processing conditions (Solution treated, Heat treated, Cryogenic treated). The machining performance are studied by the input parameters; cutting speed (60, 90, 120 m/min) and feed rate (0.06, 0.12, 0.18 mm/rev) with a constant depth of cut of 0.5mm using Taguchi’s L9 design. The responses like, surface quality, wear on the tool, and forces generated for all three specimens are studied. The hardness of all three components is measured using Vicker’s micro-hardness tester. The experimental results proved that feed rate is the most influential parameter in deciding, surface roughness, cutting force and tool wear. The utility concept approach is applied and found, solution treated sample with 120 m/min of cutting speed and 0.06 mm/rev of feed rate produces optimal results in all three response criterion.

Machinability Investigations on Aerospace Custom 450 Alloy Using TiAlN/TiCN, TiCN/TiAlN Coated and Uncoated Carbide Tools

In this present research, the machinability studies of TiAlN/TiCN, TiCN/TiAlN coated and uncoated inserts were investigated on machining custom 450 alloy. The machining input parameters such as feed rate (f), cutting speed (V) and depth of cut (d) are set using orthogonal array. The machining output parameters such as surface roughness, tool wear and cutting forces were studied for its parametric contribution and it was analyzed using Analysis of Variance (ANOVA). Further, the tool wear obtained was studied using scanning electron microscopic images and energy dispersive spectroscopy analysis was conducted to check the addition of work material elements to the coated tool surface. The results show that, the feed rate is the most contributing factor in deciding resultant forces, surface roughness and tool wear respectively. TiAlN/TiCN coated carbide tool has obtained improved machinability, when compared to TiCN/TiAlN coated carbide and uncoated carbide inserts. To obtain one optimal level for all three responses of three types of tools, multi criteria decision making approach, named utility concept approach is selected. Based on the MCDM analysis, it is found that trial number 4 gives better experimental output of improved surface integrity, lower resultant force and less tool wear for all types of tools.

Selection of Suitable Control Parameters for Proper High-Resolution Deposition Performance of E-Jet Microfabrication Process

E-jet is a high-resolution microfabrication technology. Its operation depends on several process control parameters like applied voltage, flow rate of the material, stand-off height, type of ink material. High-resolution deposition along with high ejection frequency is the performance parameter of E-jet. In the present study, an attempt is made to design the process parameters in such a way that it could simultaneously satisfy both the performance characteristics of the E-jet process. A Taguchi robust design-based utility concept is applied to optimize the multi-response E-jet process through a case study. The optimization result is compared with another multi-objective optimization method called Grey relational grade analysis. The comparative analysis showed that both the methodologies identified the same process parameter combination for improved E-jet performance. Analysis of variance found applied voltage is the most influential control factor in the investigated region. The anticipated improvement in performance shows the successful implementation of the aforesaid methodology.

Operating Conditions Optimization via the Taguchi Method to Remove Colloidal Substances from Recycled Paper and Cardboard Production Wastewater

Optimization of the ultrafiltration (UF) process to remove colloidal substances from a paper mill’s treated effluent was investigated in this study. The effects of four operating parameters in a UF system (transmembrane pressure (TMP), cross-flow velocity (CFV), temperature and molecular weight cut-off (MWCO)) on the average permeate flux (Jv), organic matter chemical oxygen demand (COD) rejection rate and the cumulative flux decline (SFD), was investigated by robust experimental design using the Taguchi method. Analysis of variance (ANOVA) for an L9 orthogonal array were used to determine the significance of the individual factors, that is to say, to determine which factor has more and which less influence over the UF response variables. Analysis of the percentage contribution (P%) indicated that the TMP and MWCO have the greatest contribution to the average permeate flux and SFD. In the case of the COD rejection rate, the results showed that MWCO has the highest contribution followed by CFV. The Taguchi method and the utility concept were employed to optimize the multiple response variables. The optimal conditions were found to be 2.0 bar of transmembrane pressure, 1.041 m/s of the cross-flow velocity, 15 °C of the temperature, and 100 kDa MWCO. The validation experiments under the optimal conditions achieved Jv, COD rejection rate and SFD results of 81.15 L·m−2·h−1, 43.90% and 6.01, respectively. Additionally, SST and turbidity decreased by about 99% and 99.5%, respectively, and reduction in particle size from around 458–1281 nm to 12.71–24.36 nm was achieved. The field-emission scanning electron microscopy images under optimal conditions showed that membrane fouling takes place at the highest rate in the first 30 min of UF. The results demonstrate the validity of the approach of using the Taguchi method and utility concept to obtain the optimal membrane conditions for the wastewater treatment using a reduced number of experiments.