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The scheduling of both absorption cycle and vapour compression cycle chillers in trigeneration plants is investigated in this work. Many trigeneration plants use absorption cycle chillers only but there are potential performance advantages to be gained by using a combination of absorption and compression chillers especially in situations where the building electrical demand to be met by the combined heat and power (CHP) plant is variable. Simulation models of both types of chillers are developed together with a simple model of a variable-capacity CHP engine developed by curve-fitting to supplier's data. The models are linked to form an optimisation problem in which the contribution of both chiller types is determined at a maximum value of operating cost (or carbon emission) saving. Results show that an optimum operating condition arises at moderately high air conditioning demands and moderately low power demand when the air conditioning demand is shared between both chillers, all recovered heat is utilised, and the contribution arising from the compression chiller results in an increase in CHP power generation and, hence, engine efficiency. [ABSTRACT FROM AUTHOR]

The design and response of ground source heat pumps coupled to vertical closed loop arrays in UK domestic applications are investigated in this article. Two typical UK house types are selected as the vehicle for the study and a detailed dynamic thermal modelling method is used to arrive at time-series heating demands for the two houses. A new empirical heat pump model is derived using experimental data taking into account the deteriorating performance of the heat pump during periods of light load. The heat pump model is incorporated into an existing numerical ground model and completed with a classical effectiveness type heat exchange model of the closed loop array. The model is used to analyse array sizing and performance over an extended time period, as well as sensitivity of the design to soil conductivity and borehole heat exchanger resistance and sensitivity to over-sizing and part-load behavior of the heat pump. Results show that the UK's standard for ground source design (the Microgeneration Certification Scheme) may lead to under-estimated array sizes and that heating system over-sizing and deleterious part-load heat pump performance can add up to 20% to the electrical consumption of these systems. [ABSTRACT FROM AUTHOR]

The article focuses on excavation of the wreck of the British Postal Packet Hanover, which sank in Hanover Cover off the coast of North Cornwall, England in 1763. It talks about the methodology of excavation efforts which used a jack-up rig and unmanned submersible pumps and hand-held suction dredges to reduce sand levels. It comments on items recovered from the wreck, including a copper-alloy bell, a longshank anchor, and a total of 60 guns and cannon ranging from one to nine pounders.

This research has demonstrated that even in a small urbanised country like Britain, communities can still be remote. The paper analyses the nature of remote settlements and suggests that beyond the rural idyll, there are deprived communities. In order to obtain real data, a study area in the North Pennines was selected. The types of remote communities were evident throughout the study area and one of each type was selected for further study. It became clear that villages with an industrial base had most potential, due to high energy demand, vulnerability and community involvement. A village with a high measure of multiple deprivation and suffering from fuel poverty was chosen for a more detailed investigation. Energy demand profiles were developed and candidate technologies nominated. The latter were tested by filters that assessed fitness for application, robustness and autonomy. The most appropriate combinations of technologies were proposed. The residents and their community representatives were involved in the process and recognised the benefits of the proposals to themselves and others. [ABSTRACT FROM AUTHOR]

New and updated multi-century tree-ring chronologies from living oak trees, remnants, and archeological beams from across the Driftless Area of southwest Wisconsin and northeast Iowa, USA, were developed to fill a spatial gap in the network of available tree-ring chronologies. We produced a robust 303-year summer drought reconstruction (June–August Palmer's Modified Drought Index (PMDI): r 2 = 0.45) that identified clusters of extreme droughts and pluvials (PMDI ≤ –4.0 or ≥ 4.0) in the early 1700s and more even distributions of drought conditions, with the exception of the post 1930s period when drought became relatively infrequent. Compared to the Living Blended Drought Atlas (LBDA) and the North American Drought Atlas (NADA), our reconstruction more accurately represented moderate moisture conditions across the Driftless Area, the NADA and LBDA more closely represented extreme pluvials, and our reconstruction and the LBDA better represented extreme drought years. The three reconstructions largely captured the same high-frequency variability in drought conditions and differed most at low frequencies. Significant correlations were identified between our reconstruction and corn (r = 0.30, n = 91, p = 0.002) and soybean (r = 0.25, n = 81, p = 0.012) yields, with the strength of the correlations increasing over recent decades suggesting a tighter coupling of interannual climate variability and crop productivity in the region. Superposed epoch analyses indicated significantly wetter conditions in the Driftless Area two years after major volcanic eruptions. In the context of long-term climatic variability, the Driftless Oaks drought reconstruction demonstrated that drought and pluvial conditions more extreme than those experienced during the instrumental record have occurred in the past. [ABSTRACT FROM AUTHOR]

The UK is currently suffering great overheating issues in summer, especially in residential buildings where no air-conditioning has been installed. This overheating will seriously affect people's comfort and even health, especially for elderly people. Phase change materials (PCMs) have been considered as a useful passive method, which absorb excessive heat when the room is hot and release the stored heat when the room is cool. This research has adopted a simulation method in DesignBuilder to evaluate the effectiveness of using PCMs to reduce the overheating issues in UK residential applications and has analyzed potential factors that will influence the effectiveness of overheating. The factors include environment-related (location of the building, global warming/climate change) and construction-related (location of the PCM, insulation, heavyweight/lightweight construction). This research provides useful evidence about using PCMs in UK residential applications and the results are helpful for architects and engineers to decide when and where to use PCMs in buildings to maintain a low carbon lifestyle. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the performance comparison of a waste heat driven Organic Rankine Cycle (ORC) powered Vapour Compression Refrigeration (VCR) system and a waste heat driven NH3–H2O Absorption Refrigeration (AR) system were carried out through modelling and simulation using IPSEpro PSE simulation tool. The simulation result shows that at the given design constraints, the ORC driven VCR system gives a better COP and second law efficiency than the AR system. Also at the breakeven pressure ratio (pressure ratio at which the COP of both system is the same) the ORC driven VCR system also gives a better second law efficiency than the AR system. However, at pressure ratios higher than the breakeven point, performance behaviour seems to contradict the well known notion that systems with low irreversibility should be more efficient that those with high irreversibility. This is a paradox and might be as a result of high number of thermal systems in the AR system. However, the trend in the COP and Φ obtained for each of the systems conforms to expectation (i.e. increase in COP leads to decrease in Φ). [Copyright &y& Elsevier]