Authors:Paine S; James P, Bahaj A. Pages: 109 - 115 Abstract: Combined Heat and Power (CHP) systems can satisfy thermal and electrical demand within cities. But, operating CHP outside of optimal conditions can result in performance below the predicted level. This study uses a 6-year dataset collected by a Local Authority (LA) from a CHP-led heat network. The results show, the studied CHP electrical output fell by around 30% and was not quickly rectified. This resulted in an estimated loss of revenue for the LA of £18 500. The paper highlights the importance of a simple method to review key operational data from a CHP-led system and ensure consistent management and output. PubDate: Mon, 12 Mar 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty001 Issue No:Vol. 13, No. 2 (2018)
Authors:Al-Sallal K; AbouElhamd A, Bin Dalmouk M. Pages: 116 - 121 Abstract: This article investigates how daylight performs in traditional UAE buildings that were turned into museums with specific focus on museum lighting requirements and effect on artefacts. The study used several methods such as on-site measurements, data collection and analysis, and computer simulation. It depended on the climate-based daylighting metric daylighting autonomy. The lighting performance was evaluated throughout the space of a representative model of traditional museum considering the design of the exhibit space and the light sensitivity of traditional artefacts. The results were analysed and design recommendations were presented to improve the overall luminous environment. PubDate: Fri, 02 Mar 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty003 Issue No:Vol. 13, No. 2 (2018)
Authors:Eloka-Eboka A; Onunka C, Inambao F. Pages: 122 - 130 Abstract: A sustainable micro-algal biofuel process plant was hypothetically and detailed-designed for the production of value products from algae. The process plant cultures algae through controlled growth and processes: production of biomass, extraction of lipids and biofuels and refinement into finished products. The start-off feedstock was Nannochloropsis spp. and the four end products produced were bio-kerosene, methane, biomass slurry and CO₂. The algae were grown to maturity within the least allowable possible time under controlled conditions. From an in-depth analysis of the customer specifications, concept development and selection, the study defines an overall depiction of the end products from the concepts evaluated by using the Pugh matrix and Six sigma methodologies. DMADV approach was implemented.The process finally generated an economically viable algae biomass for conversion to biofuels and other viable products. This paper focuses on the process planning, criteria/concept selection, design optimization with necessary characterizations which were filtered into measurable characteristics for the design of an operable, sustainable functioning plant. PubDate: Wed, 21 Feb 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty004 Issue No:Vol. 13, No. 2 (2018)
Authors:Shuai J; Cheng X, Liu J, et al. Pages: 131 - 139 Abstract: Based on the 873 questionnaires collected from six cities in four provinces in China, we made a quantitative analysis of different types of consumers’ expectations for government low-carbon subsidies by using the SPSS. The results indicate that: (1) Significant differences exist in the ‘expectations for government subsidies on low-carbon products’ from different types of consumers; there are significant differences among consumers with different monthly income, educational attainment and age on the ‘expectations for government subsidies on low-carbon products’, but the difference is not significant for the consumers in different regions or gender. (2) Monthly income and educational attainment exert significant influences on consumer ‘expectations for government subsidies on low-carbon products’, and the influence of monthly income is the biggest. Finally, we put forward policy recommendations accordingly. PubDate: Wed, 21 Feb 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty005 Issue No:Vol. 13, No. 2 (2018)
Authors:Maleki A. Pages: 140 - 147 Abstract: In power systems, meeting the electricity demand of remote regions is an imperative issue. Considering economic aspects, reliability and pollution concerns, combination of diesel generator and renewable energy sources like wind turbines (WTs), photovoltaic (PV) systems and fuel cells (FCs) can be an effective way to meet the demand of off-grid loads. In a cost-effective hybrid system, it is indispensable to optimize the number of components. In this paper, a PV/WT/FC/diesel system with different fuel prices is considered for electrification to a remote area and is optimized by a discrete simulated annealing algorithm, named DSA. The sizing problem is solved by considering different hybrid systems and two scenarios related to the cost of the diesel fuel. PubDate: Tue, 06 Mar 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty006 Issue No:Vol. 13, No. 2 (2018)
Authors:Wu Y; Lu Y, Chou D. Pages: 148 - 160 Abstract: This article presents field studies and questionnaire survey on the indoor air quality (IAQ) in library rooms in University of Science and Technology Beijing in April 2016, with no heating, to find out actual situation of IAQ in university library. Nine rooms equipped without centralized air-conditioning system were carefully selected for the test. Results showed that each room had diverse indoor thermal environment and concentrations of CO2, PM2.5, formaldehyde and TVOC. The concentration of CO2 ranged from 575 to 2400 ppm, PM2.5 concentration was 40–70% of the outdoor, the highest concentration of formaldehyde and TVOC was ~0.042 and 0.285 mg m−3, respectively with half of the upper limit. The concentrations of CO2 and PM2.5 in the holding-reading rooms were higher than that in the rooms only holding books. The situation of formaldehyde and TVOC concentrations was just opposite. The correlations between satisfaction of IAQ and the concentrations of indoor air pollutants were not as a constant, but changing with different rooms. Based on gray system theory, satisfactions were affected seriously by CO2 and PM2.5. One improving plan with the theme of ‘ventilating rapidly along with purifying’ was determined based on a general mass balance equation. In theory, IAQ can be improved <5 min for the most unfavorable condition. Through analysis, requirements of fresh air and functionality of the space usages should be considered in the ventilation or central air-conditioning system design. PubDate: Sat, 24 Feb 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty007 Issue No:Vol. 13, No. 2 (2018)
Authors:Corberán J; Cazorla-Marín A, Marchante-Avellaneda J, et al. Pages: 161 - 176 Abstract: This article presents the characteristics and performance of an innovative dual source heat pump (DSHP) for heating, cooling and domestic hot water (DHW) production. The research work was carried out in the framework of the H2020 European project: Geot€ch ‘GEOthermal Technology for economic Cooling and Heating’. The DSHP is able to choose the most favourable source/sink in such a way that it can work as an air-to-water heat pump using the air as a source/sink, or as a brine-to-water heat pump coupled to the ground. The DSHP is manufactured as an outdoor ‘plug & play’ unit, working with R32 refrigerant and including a variable speed compressor, which gives full capabilities for an efficient modulating operation. The DSHP was fully characterized in steady state conditions at the IUIIE laboratory. In order to assess its dynamic performance and to identify key control strategies to optimize its annual operation, a complete integrated model of the DSHP system in TRNSYS including the DSHP and all the other system components was developed. A first energy assessment, carried out for an office building located in the Netherlands, proves that the DSHP system would be able to reach a similar efficiency than a pure ground source heat pump (GSHP) system with half the ground source heat exchanger area needed. Therefore, the DSHP system could become a cost-effective alternative solution for heating, cooling and DHW production in buildings, as the initial investment would be significantly reduced compared to GSHPs, with similar or even higher energy efficiency. PubDate: Fri, 02 Mar 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty008 Issue No:Vol. 13, No. 2 (2018)
Authors:Chen H; Niu H, Zhang L, et al. Pages: 177 - 183 Abstract: The electrical performance of photovoltaic (PV) panel is affected by PV cell temperature. The lower PV working temperature leads to higher electrical efficiency and more power outputs. In this paper, heat pipes are used to absorb heat from PV panel for cooling, meanwhile, the absorbed heat is made full use for producing hot water with the combination of heat pump. A heat pipe PV/thermal (PV/T) heat pump system is proposed in this paper. The performance of the system is tested and the electrical performance between PV/T panel and traditional PV panel is compared under the heating mode and heat charging mode. The results show that the daily average values of electrical efficiency, thermal efficiency, COPth and COPPV/T are 12.2%, 33.9%, 2.78 and 3.40 in heating mode respectively, while the values are 12.9%, 25.3%, 1.96 and 2.52 in heat charging mode. The performance of heating mode is better than that of heat charging mode. The electrical efficiency of PV/T panel is improved relatively by 25.7% and 14.2% compared with traditional PV panel under the heating mode and heat charging mode, respectively. PubDate: Sat, 24 Mar 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty009 Issue No:Vol. 13, No. 2 (2018)
Authors:Chen Y. Pages: 184 - 190 Abstract: In order to ensure the cleanliness of operating room, clean air conditioners are installed in the clean operation departments in hospitals in China. Purification air conditioning system is an air conditioning system with a special function that ensures the cleanliness of the operating room and the required temperature and humidity in the operating room to avoid infection. This paper took the energy-saving design of the clean air-conditioning system of the clean operation department of the First Affiliated Hospital of Wenzhou Medical College, Zhejiang, China, as an example to illustrate the energy-saving methods such as layout optimization, air-conditioning division, secondary return air setting and operation mode adjustment. The energy consumption of primary return air technology and secondary return air technology was calculated. The results showed that energy-saving design could save nearly one-third of energy, improve the level of air-conditioning operation and management, reduce costs, and improve resource utilization, which is of great significance to social development. PubDate: Thu, 12 Apr 2018 00:00:00 GMT DOI: 10.1093/ijlct/cty013 Issue No:Vol. 13, No. 2 (2018)
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