Integrating power flow modelling with building simulation

The inclusion of photovoltaic facades and other local sources of both heat and power within building designs has given rise to the concept of embedded generation: where some or all of the heat and power demands are produced close to the point of use. This paper describes recent work to simulate the heat and power flows associated with both an embedded generation system and the building it serves. This is achieved through the development of an electrical power flow model and its integration within the ESP-r simulation program

Developing and testing a generic micro-combined heat and power model for simulations of dwellings and highly distributed power systems

This paper elaborates an approach to the modelling of domestic micro-combined heat and power (μ-CHP) using a building simulation tool that can provide a detailed picture of the environmental performance of both the μ-CHP heating system and the dwelling it serves. The approach can also provide useful data for the modelling of highly distributed power systems (HDPS). At the commencement of the work described in this paper no μ-CHP device model that was compatible with a building simulation tool was available. The development of such a model is described along with its calibration and verification. The simulation tool with the device model was then applied to the analysis of a dwelling with a Stirling engine-based heating system. Different levels of thermal insulation and occupancy types were modelled. The energy and environmental performance of the μ-CHP device was quantified for each case; additionally, the potential for its participation in the control and operation of an HDPS was assessed. Analysis of the simulation results indicated that the parasitic losses associated with the μ-CHP system balance of plant reduced the overall heating system efficiency by up to 40 per cent. Performance deteriorated with increasing levels of insulation in the dwelling, resulting in reduced thermal efficiency and increased cycling, though overall fuel use was reduced. The analysis also indicated that the device was generally available to participate in HDPS control for greater than 90 per cent of the simulation time. The potential length of the participation time ranged from 1 to 800+min and depended upon the state of the μ-CHP system thermal buffer and prevailing heat loads. Probabilities for different participation times and modes were calculated

The role of DSM + C to facilitate the integration of renewable energy and low carbon energy technologies

Recent legislation and building regulations have aiming to reduce the energy demands of buildings and include renewable based micro-generation technologies. Due to the variations in energy delivery from these technologies, optimised control over building plant and loads is essential if we are to achieve a good demand-supply match and achieve a reduction in energy demands. This paper reports on research being undertaken as part of the UK EPSRC SuperGen Future Networks programme, specifically relating to the development of algorithms for simulating dynamic demand side control strategies to identify demand-supply matching options when deploying building integrated renewable energy and low carbon technologies. The development of demand side management and control (DSM+c) is a means to improve the dynamic demand-supply match taking account of the available demand side management capacity and time of occurrence. The principle of the developed DSM+c algorithms is to maximise the available control capacity which will enable a better demand-supply match while minimising any impact on users. This paper will demonstrate the application of DSM+c to improve the energy efficiency of a building (e.g. reduced total capacity), restructure the demand pattern via load shifting and switching (e.g. on/off or proportional control) to one more favourable to building integrated renewables. The impact of different control strategies on demand profile restructuring will be demonstrated using simulation to alter the settings of the DSM+c parameters - such as priority, methods and periods - for a given demand profile. The paper will conclude by presenting the outcomes from a case study using the decision support/design tool, MERIT where the developed DSM+c algorithms have been implemented to better facilitate the match between demand and building integrated clean energy supply technologies at the individual multi-familiy building level

Do we really drive as we feel?

Learning to drive has been conceptualised as a series of stages which take the learner from mastery of the basic mechanics of driving, through anticipation of other road user's behaviour, to the development of a driving style consistent with the skill achieved in the first two stages (Parker & Stradling, 2002). Deery (1999) suggests that hazard perception is one of the main skills to be acquired in the second stage and that this skill is poorly developed in the inexperienced (and usually young) driver

Characteristics of cocaine block of purified cardiac sarcoplasmic reticulum calcium release channels

We have examined the effects of cocaine on the SR Ca2+ release channel purified from canine cardiac muscle. Cocaine induced a flicker block of the channel from the cytoplasmic side, which resulted in an apparent reduction in the single-channel current amplitude without a marked reduction in the single-channel open probability. This block was evident only at positive holding potentials. Analysis of the block revealed that cocaine binds to a single site with an effective valence of 0.93 and an apparent dissociation constant at 0 mV (Kd(0)) of 38 mM. The kinetics of cocaine block were analyzed by amplitude distribution analysis and showed that the voltage and concentration dependence lay exclusively in the blocking reaction, whereas the unblocking reaction was independent of both voltage and concentration. Modification of the channel by ryanodine dramatically attenuated the voltage and concentration dependence of the on rates of cocaine block while diminishing the off rates to a lesser extent. In addition, ryanodine modification changed the effective valence of cocaine block to 0.52 and the Kd(0) to 110 mM, suggesting that modification of the channel results in an alteration in the binding site and its affinity for cocaine. These results suggest that cocaine block of the SR Ca2+ release channel is due to the binding at a single site within the channel pore and that modification of the channel by ryanodine leads to profound changes in the kinetics of cocaine block

Simulation-assisted control in building energy management systems

Technological advances in real-time data collection, data transfer and ever-increasing computational power are bringing simulation-assisted control and on-line fault detection and diagnosis (FDD) closer to reality than was imagined when building energy management systems (BEMSs) were introduced in the 1970s. This paper describes the development and testing of a prototype simulation-assisted controller, in which a detailed simulation program is embedded in real-time control decision making. Results from an experiment in a full-scale environmental test facility demonstrate the feasibility of predictive control using a physically-based thermal simulation program