Insulation Options Research Articles

Multi-criteria Optimization of Insulation Options for Warmth of Buildings to Increase Energy Efficiency

Increasing energy efficiency and reducing CO2 are among of the main drivers of modern scientific research. One of the solutions to increase energy efficiency is the selection of the insulation of the walls on buildings. The aim of this study is to optimize such insulation taking onto the account several criteria.The paper analyzes the state of the buildings in Sarajevo, precisely in Alipasino polje, which the company KJKP “Toplane- Sarajevo” supplies with thermal energy. Several options for building warmth are considered and evaluated by selected criteria, after that multi-criteria optimization method VIKOR was applied to rank the options and select the best one. Optimization on the basis of relevant criteria is done before making investment project for warmth buildings, to provide input parameters for designing and decision-making processes.

Thermal-fluid assessment of the design options for reactor vessel cooling in a prismatic core VHTR

The design of the reactor pressure vessel is an important issue in the VHTR design due to its high operating temperature. The extensive experience base in Light Water Reactor makes SA508/533 steel emerge as a strong candidate for the VHTR reactor vessel but requires maintaining the vessel temperature below the ASME code limit. To meet the temperature requirement, three types of vessel cooling options for a prismatic core VHTR are considered: an internal vessel cooling, an external vessel cooling, and an internal insulation. The performances of the vessel cooling options are evaluated by using a system thermo-fluid analysis code and a commercial computational fluid dynamics code during normal operation and accidents. The results suggested that the internal vessel cooling with the modified inlet flow path will be a promising option. The external cooling option does not ensure an effective cooling of the RPV. The insulation option provides an effective reduction of the RPV temperature in the normal and accident conditions but reduces the fuel safety margin during the accidents, requiring careful consideration before the implementation.

USING SIMULATION TO EVALUATE AND IMPROVE THE THERMAL PERFORMANCE OF COURTYARD OFFICE BUILDINGS IN CAIRO

This paper explores the implications of alternative design options for the thermal performance of office buildings in Cairo, Egypt. Typical courtyard office floor plan was selected for the investigation. Multiple design alternatives were considered involving various glazing and shading types, shading schedules, thermal insulation options, orientations, and ventilation scenarios. A numeric thermal simulation application was used to model the performance of these alternatives parametrically*1. The results show the significant degree to which design measures could reduce cooling requirements of (and overheating tendencies in) courtyard office buildings in Cairo.

New Trend in Oilfield Flow-Assurance Management: A Review of Thermal Insulating Fluids

Summary Flow assurance has been one of the major considerations in deep-water completion design, in which undesired heat loss from production tubing contributes to the formation of gas hydrates and causes the deposition of paraffin and asphaltene materials. Traditionally, controlling annular heat loss has been achieved with the injection of steam, the application of silicate foam, the pressurization of the annulus with inert gas, the use of gelled oil as an insulating packer fluid, and the use of vacuum insulated tubing (VIT). Each of these applications, however, has drawbacks because of either its working mechanism or the higher cost associated with the technology. To secure the insulation of the wellbore and to reduce heat transfer from the production tubing to the surrounding areas, various aqueous insulating fluid systems with superior thermal properties have been developed in recent years. Field applications of these fluids have demonstrated significant reduction in heat loss by reducing conduction and minimizing convection. These thermal insulating fluids have been implemented with great success in more than 75 deepwater riser and packer applications in the Gulf of Mexico (GOM) over the last several years. Case histories have demonstrated that installation of these water-based insulating fluids is an effective alternative to conventional insulation options and is becoming the preferred insulation method in many deep-water projects. This paper will highlight the evolution of different insulating fluid systems and the field experience with each system. Proper testing methods relevant to oilfield flow assurance will be discussed and testing results for these fluids will be detailed. Field cases in the GOM will be summarized, and the effectiveness of these fluid systems will be demonstrated.

Innovative high-pressure laminate insulation for fusion magnets

High-pressure laminate (HPL) composite materials, such as G-10, have been used for many years in both the electrical and magnet industry as insulation for demanding applications. Because of their relative ease of fabrication and ability to be inspected prior to magnet installation, these materials have remained an attractive insulation option for current magnet designers. However, composite insulation for use in many new Next Step Option (NSO) fusion devices must meet an increasingly demanding set of requirements, including cryogenic and elevated temperature performance while withstanding higher radiation levels. The lack of performance in high radiation environments by materials such as G-10 has led Composite Technology Development, Inc. (CTD) to develop a series of new, innovative HPL insulation systems that can meet the new fusion magnet challenges. Material development has focused on highly radiation-resistant resin systems, as well as lower radiation resistant, low cost alternatives. Prototype laminates have been fabricated and evaluated by a leading industrial partner to ensure their suitability for large-scale production. This paper will present several new insulation systems capable of being fabricated in the HPL process, provide processing characteristics, along with mechanical and electrical property data.

Evaluating uncertainty in environmental life-cycle assessment. A case study comparing two insulation options for a Dutch one-family dwelling.

The evaluation of uncertainty is relatively new in environmental life-cycle assessment (LCA). It provides useful information to assess the reliability of LCA-based decisions and to guide future research toward reducing uncertainty. Most uncertainty studies in LCA quantify only one type of uncertainty, i.e., uncertainty due to input data (parameter uncertainty). However, LCA outcomes can also be uncertain due to normative choices (scenario uncertainty) and the mathematical models involved (model uncertainty). The present paper outlines a new methodology that quantifies parameter, scenario, and model uncertainty simultaneously in environmental life-cycle assessment. The procedure is illustrated in a case study that compares two insulation options for a Dutch one-family dwelling. Parameter uncertainty was quantified by means of Monte Carlo simulation. Scenario and model uncertainty were quantified by resampling different decision scenarios and model formulations, respectively. Although scenario and model uncertainty were not quantified comprehensively, the results indicate that both types of uncertainty influence the case study outcomes. This stresses the importance of quantifying parameter, scenario, and model uncertainty simultaneously. The two insulation options studied were found to have significantly different impact scores for global warming, stratospheric ozone depletion, and eutrophication. The thickest insulation option has the lowest impact on global warming and eutrophication, and the highest impact on stratospheric ozone depletion.

Molecular structure and physical properties of E‐beam crosslinked low‐density polyethylene for wire and cable insulation applications

AbstractCrosslinking of homemade low‐density polyethylene (LDPE) was performed by electron‐beam (EB) irradiation. The gel content of the EB‐exposed LDPE was determined by the solvent‐extraction method. The degree of crosslinking was also evaluated by a hot set measuring test. The results obtained from both the gel–sol and the hot set methods showed that the degree of crosslinking was dependent on the deposited energy in LDPE samples. Increasing the absorbed dose increased the degree of network formation. The LDPE with higher molecular weight yielded higher efficiency of crosslinking at the same irradiation dose. The effect of irradiation dose on the molecular weight between crosslinks (Mc), glass‐transition temperature, and free volume were calculated. Mechanical test results showed that the tensile strength of the samples increased with increase in the irradiation dose up to 150 kGy and then slightly decreased with further increasing the deposited energy. The elongation at break decreased with increasing the absorbed dose. The results obtained from differential scanning calorimetry exhibited a small reduction in the melting point and the degree of crystallinity of the EB‐exposed LDPE samples compared to those of the untreated samples. The effect of crosslinking on the electrical properties of the irradiated samples was insignificant. The dielectric constant of the treated samples remained nearly constant within the irradiation dose range, although the dissipation factor increased slightly with increasing the absorbed dose. The results obtained from characterizing the EB‐induced crosslinking of homemade polyethylene, including LH0030 and LH0075, showed the higher molecular weight polyethylene (LH0030) as a preferred option for wire and cable insulation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1959–1969, 2002

Modelling of SO 2 pollution changes with improving thermal performance of buildings in Gebze, Turkey

We present the results of a dispersion-modelling study of SO 2 concentrations. Overall heat-transfer coefficients ( U-values) of existing wall systems in Gebze, Turkey, have been measured. Different insulation options for improvement of the thermal performance of existing wall systems have been chosen. Comparative energy-consumption analyses for each option have been performed according to ISO 9164. SO 2 emissions were compiled for existing conditions and calculated for control options. Emissions, meteorological and topographical data were used in the USEPA-approved ISCLT model to predict winter-average SO 2 contributions to air quality. The effects of using different exterior wall systems to these contributions were investigated.

Optimal financial choices for the insulation of buildings

A method for determining the economic priorities with which various thermal insulation options should be adopted for domestic purposes is described and some results presented.