Investigation of hydraulic imbalance for converting existing boiler based buildings to low temperature district heating

The hydraulic balance of heating network is considered as a pre-condition for the implementation of low temperature district heating (LTDH). Its imbalance result into high energy consumption and heat-losses in the network. In this study, a novel hydraulic model is presented which investigates hydraulic imbalance in the LTDH network, using real weather and hourly monitored operational heating data from an existing boiler based building. Analysis of delta t in space-heating system shows that the delta t is maximum when the outside air temperature is lowest and it decreases with increase in outside air temperature. Furthermore, the hydraulic imbalance is analysed for four different control scenarios with the aim to find an optimum scenario with minimum pumping power, energy consumption and heat-losses in the LTDH network. Results show that the hydraulic imbalance is due to the absence of flow-limiters and balancing valves on the return pipe and thermostatic radiator valves (TRVs) alone are unable to maintain hydraulic balance in the space-heating system of buildings. Moreover, the control scenario with variable flow-rate and fixed supply water temperature from the sub-station is found to be optimum. Compared to the constant flow-rate scenario, the pumping power, energy consumption and heat-losses in the LTDH network are reduced by approximately 2%, 63% and 14%, respectively

4D printing inflatable silicone structures

This article details steps in creating low-power artificial muscles using 3D printing. It describes a manufacturing system that can be used to fabricate seamless tubular dielectric elastomer actuators (DEA), for eventual use in biorobotic devices. The focus is on producing passive elastomeric components of DEA and the dimensional changes that occur after printing is complete. A four-axis printing system is described, capable of spray depositing multilayer tubular silicone membranes onto an air-permeable mandrel. Mechanical strain was imparted in the membranes by means of inflation. A laser measurement system was constructed to act as a 3D scanner, which measured the shape of the inflated ‘‘balloon.’’ The surface shape was reconstructed in software using the parametric modeling tool Grasshopper. Seamless auxetic tessellations were calculated across the entire surface, and then converted to CNC GCode. These toolpaths were then physically extruded over the surface of the balloon, stacked five layers high. When the extruded silicone structure was completely cured, the pneumatic strain was released, allowing the structure to collapse evenly. The compression in the printed structure was balanced by the tension in the stretched membranes, thus producing a minimum energy structure

Assessing riveted connections to Eurocode 3

The focus of this paper is the assessment of wrought iron and early steel riveted connections in the future, with recommendations as to how different codes currently deal with the assessment and what may change if alternative codes are adopted. As British standards are being replaced by Eurocodes for design, it is inevitable that assessment codes of practice based on British standards will be replaced by those based on Eurocodes. This progression will ensure that future structures are designed and assessed using codes based on similar philosophies. However, this will also lead to older structures designed according to older codes based on different philosophies and constructed of materials not covered by the Eurocodes also being assessed according to Eurocode-based assessment codes. A similar situation already exists with structures being assessed using British standard-based assessment codes, which were written for the design of steel structures. This has resulted in the leading asset-owning organisations, such as Network Rail and Highways England, including guidance on adapting calculations to account for different material types

Adhesive connections in timber: a comparison between rough and smooth wood bonding surfaces

The use of adhesive anchors for wooden constructions is an efficient technology to connect and design timber members in new timber structures and to rehabilitate the damaged structural members of historical buildings. Due to the lack of standard regulation in this specific area of structural design, designers’ choices are still supported by test analysis that enables knowledge, and the prediction, of the structural behaviour of glued in rod joints. The paper outlines an experimental research activity aimed at identifying the tensile resistance capacity of several new adhesive joint prototypes made of epoxy resin, steel bar and timber, Oak and Douglas Fir species. The development of new adhesive connectors has been carried out by using epoxy to glue stainless steel bars into pre-drilled holes, characterised by smooth and rough internal surfaces, in timber samples. The realization of a threaded contact surface using a specific drill bit has led to an improved bond between wood and epoxy. The applied changes have also reduced the cost of the joints' production. The paper presents the results of this parametric analysis and a Finite Element analysis that enables identification and study of the internal stress distribution in the proposed adhesive anchors

Hyperelastic properties of platinum cured silicones and its applications in active compression

This paper presents the fundamental research of design, development, and evaluation of an active compression system consisting of silicone based inflatable mini-bladders, which could be used in applying radial pressure for the treatment of venous disease. The use of mini-bladders will nullify the effect of radius of curvature and provide a higher resolution to the pressure distribution. They are designed with two elastomeric layers and inflation is limited only to one side. The minibladders apply a radial force onto the treated surface when inflated, and the pressure inside minibladders could be measured using the concept of back pressure, which provides the flexibility to inflate mini-bladders to a predefined pressure. The 3-D deformation profile of the mini-bladders was analysed using finite element method (FEM) and FEM simulations were validated with experimental data, which showed good agreement within pressure region required for the treatment of venous disease. Finally, the pressure transmission characteristics of mini-bladders were evaluated on a biofidellic lower leg surrogate and the results have shown that the mini-bladders could apply a uniform pressure irrespective of the location on the leg with a 60%–70% of inlet pressure successfully transmitted onto the leg surface, while 40%–50% was available after the fat layers

Features of fully integrated renewable energy atlas for Pakistan; wind, solar and cooling

A fully integrated renewable energy atlas is presented which provides the wind and solar photo-voltaic (PV) power generation potential as well as cooling demand for Pakistan at a temporal resolution of 1-hr and spatial resolution of 14 x 14 km2. The proposed atlas uses weather based modelling for calculating renewable power generation time-series and the power-demand modelling is performed using real hourly electrical-load demand, conventional power generation and power consumption data for the year 2016. It has been found that Pakistan has much higher potential for the wind power generation than solar (PV) power generation and very good potential for the concentrated solar power. Furthermore, the optimum wind/solar power mix suggests that 95% of wind power generation and 5% of solar (PV) power generation leads to the least amount of power-shortfall. It is envisioned that the integration of renewable energy with cooling sector can be instrumental in overcoming Pakistan's electrical power-crisis. The current power-shortfall of 38.36 TW h can be resolved by installing rated wind and solar (PV) power generation capacity of 10.4 GW and 882 MW, respectively

Contemporary Trends in the Regenerative and Sustainable Built Environment:Technical and Managerial Aspects: workshop proceedings: Novel Energy for the Regenerative Built Environment: Technical and Managerial Aspects, 3-6 March 2014, Istanbul Technical University; [and] Low Carbon Buildings and Communities in the Sustainable Built Environment, 23-25 February 2015, Istanbul Technical University

As the world’s living conditions are deteriorating, the need for the regenerative and sustainable built environment is increasing. Establishment of the regenerative and sustainable built environment requires interdisciplinary work and research. For this reason, our workshop “Low carbon Buildings and Communities in the Sustainable Built Environment” supported by the British Council Researcher Links as well as our workshop “Novel Energy for the Regenerative Built Environment: Technical and Managerial Aspects” supported by the Turkish Science Foundation (TÜBİTAK) play an important role in bringing the academics from various disciplines together. This workshop proceedings book provides the proceedings of these two workshops

Innovative system for delivery of low temperature district heating

An innovative low temperature district heating (LTDH) local network is developed in Nottingham, supported by the REMOURBAN project, part of the H2020 Smart City and Community Lighthouse scheme. It was proposed that a branch emanating from the return pipe of the existing district heating system in Nottingham would be created to use low temperature heating for the first time on such scale in the UK. The development is aimed to extract unused heat from existing district heating system and to make it more efficient and profitable. The 94 low-raised flats in four maisonette blocks in Nottingham demo site have been selected to be connected to this new LTDH system. The scheme will provide a primary supply of space heating and hot water at approximately 50°C to 60°C. Innovated solutions have been put forward to overcome certain barriers, such as legionella related risks and peak loads during extreme heating seasons and occasional maintenance