A Calibration of the Solar Load Ratio Method to Determine the Heat Gain in PV-Trombe Walls

The Trombe wall is a passive system used in buildings that indirectly transfers thermal energy to the adjacent environment by radiation and convection, and directly by the thermo-circulation that arises in the air cavity delimited between a transparent and an absorbing surface. Nevertheless, the latter is painted black to increase the energy gains, but this produces a negative visual impact and promotes the overheating risk in summer. To mitigate these aspects, a hybrid Trombe wall equipped with PV panels can be employed. The PV installation results in a more pleasing wall appearance and the overheating risk reduces because part of the absorbed solar radiation is transformed into electricity. To determine the actual performance of a such system, transient simulation tools are required to consider properly the wall thermal storage features, variation of the optical properties, air thermo-circulation, and PV power production. Alternatively, regarding the traditional Trombe wall, the literature provides a simplified empirical method based on the dimensionless parameter solar load ratio (SLR) that allows for preliminary evaluations and design. In this paper, the SLR method was calibrated to determine the monthly auxiliary energy to be supplied in buildings equipped with PV-Trombe walls in heating applications. The SLR method was tuned by a multiple linear regression by data provided by TRNSYS simulation that allowed to obtain the energy performances in actual conditions of PV-Trombe walls installed on the same building but located in different localities. The comparison between the TRNSYS results and the calibrated SLR method determined average errors ranging between 0.7% and 1.4%, demonstrating the validity of the proposed methodology.

Determination of Appropriate Operation of Firefighting Facility using Fire and Evacuation Simulations

Recently, a performance-based design of a fire protection facility has been proposed that significantly contributes to the construction of safe and reliable buildings. Improving the performance of the fire protection facility will enable protection of the public along with the infrastructure. Designs focusing on the fire protection performance generally add or modify architectural aspects through fire and evacuation simulations. However, a secure evacuation system aided with CCTVs has rarely been considered as an active system. Particularly for apartments, it is very difficult to assure evacuation safety without using an active system in fire and evacuation simulations with the front door of the burning room open. Safety can be achieved by combining a passive system with an active system, on the basis that the building premises has the foundation of a passive system. The regulation on the evacuation delay time in the nation was brought in effect through the SFPE paper but was deleted since the data reliability was insufficient. Therefore, the aim of the present study is to analyze the operation of a fire protection facility required to ensure safety by planning multiple simulations of a fire and evacuation system. An apartment has been considered as an example to design the foundation for a standard evacuation safety system. An active system is applied to execute fire and evacuation simulations, with focus on the fire protection performance.

The development of an optical system for lighting various rooms with sunlight

The necessity of using light in the room, the spectral composition of which corresponds to the spectrum of the sun for a comfortable state of a person, is justified. A passive system that does not consume energy is proposed. An energy-efficient natural light system has been developed, creating a comfortable environment for the eyes, well-being and mood of a person. An experimental study of the system operation was carried out. The dependence of the light intensity on the angle of incidence in the light guide is obtained.

Applied TRL Calibration Technique Using ABCD Matrices for Bended Access Ports

Calibrating network analyzer is still an issue for bended access port devices (devices with access). Bended accesses can give additional errors which are taken into account by using a new design standards of Vector Network Analyzer (VNA) calibration. This Thru-Reflect-Line calibration technique is computed from ABCD parameters that easily allow to remove the bended port effects. This approach is based on the assumption that the Vector Network Analyzer error boxes can be considered as passive system. Furthermore, the method can be applied for de-embedding devices with bended accesses. This calibration and de-embedding technique could be applied, for example, to a coplanar circulator or a power divider measurement which have access lines at 120° from each other.

Passive system of cooling and refrigerant fluid circulation, assisted by capillary pumping

We propose a concept design of a cooling system, primarily targeting gas-insulated switchgear enclosures which use a mixture of a refrigerant fluid, such as Novec™ 649, and a non-condensable gas for electrical insulation. The novel open-loop system relies on evaporative cooling assisted by capillary pumping, and refrigerant vapor condensation on the walls of the system enclosure. The results of experiments on a laboratory prototype are presented and discussed. Besides cooling, a major benefit of the system is in facilitating the circulation of the gas mixture in the enclosure.

Analysis of Thermomechanical Stresses of a Photovoltaic Panel Using a Passive System of Cooling

In this paper, the gradient temperature and the thermomechanical stresses of a photovoltaic panel has been studied with and without heatsink. For this purpose, a three-dimensional analysis was carried out. Accordingly, a heat transfer analysis was developed. The numerical results show a cooling close to 26.7% with the proposed triangle fins compared with the rectangular fins studied before by another author, and the temperature distribution was determined. With this information, the stress analysis was carried out in order to find the effect on the panel due to the thermomechanical stresses. The aluminium frame was restricted to move freely. The resulting stresses field established the magnitude of the alternative stresses, resulting in a 6.7% drop compared with a reference panel. The guidelines of IEC 61215 have to be take into account. Due to the results obtained, the use of this kind of system in desert conditions is desirable because of its high operational temperature and due to the increase in heat transfer by the fins.

Protecting invisible children in England: how human rights education could improve school safeguarding

This article brings together two distinct but interrelated fields: human rights education (HRE) and safeguarding. It endeavours to show that the former can be beneficial for the efficacy of the latter. By extending an argument put forward recently that for HRE to be effective it must enable children to recognise and respond to lived human rights injustices, the article places this important issue within the existing framework and processes associated with safeguarding young people in formal education. It attempts to both elucidate and consolidate the connection between HRE and safeguarding, arguing that if HRE were to become an integral part of safeguarding training and delivery, children may be better equipped to recognise and speak up about violations of their human rights, rather than relying on a passive system of adult observation.

Reducing the Power Consumption of the Electrodynamic Suspension Levitation System by Changing the Span of the Horizontal Magnet in the Halbach Array

In high-speed magnetic railways, it is necessary to create the forces that lift the train. This effect is achieved by using active (EMS) or passive (EDS) magnetic systems. In a passive system, suspension systems with permanent magnets arranged in a Halbach array can be used. In this paper, an original Halbach array with various alternately arranged horizontally and vertically magnetized magnets is proposed. Correctly selected geometry allows us to obtain higher values of levitation forces and lower braking forces in relation to a system with identical horizontally and vertically magnetized elements. The effect of such a shape of the magnetic arrangement is the reduction of instantaneous power consumption while traveling due to the occurrence of lower braking forces. In order to perform a comparative analysis of the various geometries of the Halbach array, a simulation model was developed in the ANSYS Maxwell program. The performed calculations made it possible to determine the optimal dimensions of horizontally and vertically magnetized elements. The results of calculations of instantaneous power savings for various cruising speeds are also included.