scholarly journals Energy performance investigation of a district cooling system

Author(s):  
A. Bukshaisha ◽  
A. H. Beitelmal
2021 ◽  
Vol 1 ◽  
pp. 3279-3288
Author(s):  
Maria Hein ◽  
Darren Anthony Jones ◽  
Claudia Margot Eckert

AbstractEnergy consumed in buildings is a main contributor to CO2 emissions, there is therefore a need to improve the energy performance of buildings, particularly commercial buildings whereby building service systems are often substantially over-designed due to the application of excess margins during the design process.The cooling system of an NHS Hospital was studied and modelled in order to identify if the system was overdesigned, and to quantify the oversizing impact on the system operational and embodied carbon footprints. Looking at the operational energy use and environmental performance of the current system as well as an alternative optimised system through appropriate modelling and calculation, the case study results indicate significant environmental impacts are caused by the oversizing of cooling system.The study also established that it is currently more difficult to obtain an estimate of the embodied carbon footprint of building service systems. It is therefore the responsibility of the machine builders to provide information and data relating to the embodied carbon of their products, which in the longer term, this is likely to become a standard industry requirement.


2020 ◽  
Vol 10 (10) ◽  
pp. 3622 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple

The electrical power consumption of refrigeration equipment leads to a significant influence on the supply network, especially on the hottest days during the cooling season (and this is besides the conventional electricity problem in Iraq). The aim of this work is to investigate the energy performance of a solar-driven air-conditioning system utilizing absorption technology under climate in Baghdad, Iraq. The solar fraction and the thermal performance of the solar air-conditioning system were analyzed for various months in the cooling season. It was found that the system operating in August shows the best monthly average solar fraction (of 59.4%) and coefficient of performance (COP) (of 0.52) due to the high solar potential in this month. Moreover, the seasonal integrated collector efficiency was 54%, providing a seasonal solar fraction of 58%, and the COP of the absorption chiller was 0.44, which was in limit, as reported in the literature for similar systems. A detailed parametric analysis was carried out to evaluate the thermal performance of the system and analyses, and the effect of design variables on the solar fraction of the system during the cooling season.


2016 ◽  
Vol 5 (1-2) ◽  
pp. 162-170
Author(s):  
Henrik Zsiborács ◽  
Béla Pályi ◽  
Gábor Pintér ◽  
Nóra Hegedűsné Baranyai ◽  
Péter Szabó ◽  
...  

In this paper the economic aspects of the water spraying cooling technology of polycrystalline solar modules with respect to the effect of temperature on performance was examined. The main purpose of this work was to explore the economic relations of the spraying cooling technology of solar modules. In the study 5 kW PV system for residential customers, 5 kW and 50 kW PV system for business customer were studied. In Hungarian climatic conditions, considering the inflation values used, the interest rate, the annual utilization of the cooling system, the expected profit and the maintenance costs show us that neither of the cooling solutions is capable of better payback time than the reference uncooled solar PV system. The further research goal is to determine the usability of the cooling system in such countries which have on the one hand more ideal climatic conditions, on the other hand more predictable green energy feed regulations.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5038
Author(s):  
Goopyo Hong ◽  
Chul Kim ◽  
Jun Hong

In commercial buildings, HVAC systems are becoming a primary driver of energy consumption, which already account for 45% of the total building energy consumption. In the previous literature, researchers have studied several energy conservation measures to reduce HVAC system energy consumption. One of the effective ways is an economizer in air-handling units. Therefore, this study quantified the impact of the outdoor air fraction by economizer control type in cooling system loads based on actual air-handling unit operation data in a hospital. The optimal outdoor air fraction and energy performance for economizer control types were calculated and analyzed. The result showed that economizer controls using optimal outdoor air fraction were up to 45% more efficient in cooling loads than existing HVAC operations in the hospital. The energy savings potential was 6–14% of the differential dry-bulb temperature control, 17–27% of the differential enthalpy control, 8–17% of the differential dry-bulb temperature and high-limit differential enthalpy control, and 16–27% of the differential enthalpy and high-limit differential dry-bulb temperature control compared to the no economizer control. The result of this study will contribute to providing a better understanding of economizer controls in the hospital when the building operates in hot-humid climate regions.


2016 ◽  
Author(s):  
I. P. Koronaki ◽  
E. G. Papoutsis ◽  
M. T. Nitsas

Solar cooling systems offer a reliable and environmentally friendly alternative to conventional electrically driven vapor compression cooling units. Air conditioning systems powered by solar energy are very attractive because they have zero ozone depletion and global warming potential, their operational cost is low and they do not burden the electrical network during summer months. In this study, the installation of a solar cooling system in various Greek cities is examined. The system utilizes a single-stage, two-bed silica gel-water adsorption chiller driven by heat produced by solar collectors. A lumped parameter model is used to simulate the performance of the adsorption chiller. The optimum tilt of the solar collectors is calculated for each examined city in order for the collected solar energy to be maximized during the summer period (April to September). The climatic data are taken from the technical notes of Greek Regulation for Buildings Energy Performance. Then, using the f-chart cooling method the necessary collectors’ surface area is estimated for every examined city and for different types of flat plate collectors (including advanced flat plate, simple flat plate and hybrid photovoltaic thermal collectors).


2013 ◽  
Vol 281 ◽  
pp. 649-652 ◽  
Author(s):  
Dae Kyo Jung ◽  
Dong Hwan Lee ◽  
Joo Ho Shin ◽  
Byung Hun Song ◽  
Seung Hee Park

Recently, the interest in increasing energy efficiency of building energy management system (BEMS) has become a high-priority and thus the related studies also increased. In particular, since the energy consumption in terms of heating and cooling system takes a large portion of the energy consumed in buildings, it is strongly required to enhance the energy efficiency through intelligent operation and/or management of HVAC (Heating, Ventilation and Air Conditioning) system. To tackle this issue, this study deals with the BIM (Building Information Modeling)-based energy performance analysis implemented in Energyplus. The BIM model constructed at Revit is updated at Design Builder, adding HVAC models and converted compatibly with the Energyplus environment. And then, the HVAC models are modified throughout the comparison between the energy consumption patterns and the real-time monitoring in-field data. In order to maximize the building energy performance, a genetic algorithm (GA)-based optimization technique is applied to the modified HVAC models. Throughout the proposed building energy simulation, finally, the best optimized HVAC control schedule for the target building can be obtained in the form of “supply air temperature schedule”.


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