Hybrid-cooling, combined cooling, heating, and power systems

2009 ◽  
Vol 223 (5) ◽  
pp. 487-495 ◽  
Author(s):  
N Fumo ◽  
P J Mago ◽  
L M Chamra
Keyword(s):  
Power Systems ◽  
Weather Conditions ◽  
Energy Performance ◽  
Primary Energy ◽  
Climate Conditions ◽  
Hybrid Cooling ◽  
Combined Cooling ◽  
Vapour Compression ◽  
Generation Unit ◽  
Optimize Fuel Consumption

Combined cooling, heating, and power (CCHP) systems have the ability to optimize fuel consumption by recovering thermal energy from the prime mover of the power generation unit (PGU). Design of a CCHP system requires consideration, among other variables, of CCHP system components size and type. This study focuses on the analysis of hybrid-cooling, heating, and power (hybrid-cooling CCHP) systems that have an absorption chiller (CH) and a vapour compression system to handle the cooling load. The effect of the size of both cooling mechanisms is analysed in conjunction with the PGU size and efficiency. For better energy performance analysis simulations, results are presented based on the building-CCHP system primary energy consumption (PEC). Hybrid-cooling CCHP systems yield higher primary energy reduction than CCHP systems with an absorption CH alone. To account for the effect of climate conditions, hot and cold climates were considered by performing simulations for Tampa and Chicago weather conditions. The results are presented in tabular form to show the value of the PEC reduction as a function of the PGU size and efficiency, and the size of the absorption CH.

Effect of the Power Generation Unit Size on the Energy Performance of Cooling, Heating, and Power Systems

2008 ◽  
Author(s):  
N. Fumo ◽  
P. J. Mago ◽  
L. M. Chamra
Keyword(s):  
Power Generation ◽  
Energy Consumption ◽  
Building Energy ◽  
Energy Performance ◽  
Primary Energy ◽  
Energy Strategy ◽  
Climate Conditions ◽  
Power Generation Unit ◽  
Chp System ◽  
Generation Unit

Cooling, Heating, and Power (CHP) systems are a form of distributed generation that can provide electricity while recovering waste heat to be used for space and water heating, and for space cooling by means of an absorption chiller. CHP systems improve the overall thermal energy efficiency of a building, while reducing energy consumption. Since energy conservation has implications on energy resources and environment, CHP systems energy performance should be evaluated based on building primary energy consumption. Primary energy consumption includes the energy consumed at the building itself (site energy) plus the energy used to generate, transmit, and distribute the site energy. The objective of this investigation is to determine the effect of the power generation unit (PGU) size on the energy performance of CHP systems. Since CHP systems energy performance varies with the building energy profiles, in this study the same building is evaluated for three different cities with different climate conditions. This paper includes simulation results for the cases when a CHP system operates with and without a primary energy strategy. Results show that for any PGU size energy savings are guaranteed only when the primary energy strategy is applied. Since CHP system energy performance depends on the building energy use profiles, which depend on climate conditions and other factors such as building characteristic and operation, each case requires a particular analysis in order to define the optimum size of the power generation unit.

Hybrid Photovoltaic-Diesel Energy System Optimization (Case Study of Electric Power Supply for Buildings under the Weather Conditions of Montenegro)

2014 ◽  
Vol 627 ◽  
pp. 357-364 ◽  
Author(s):  
Goran Radovic ◽  
Vera Murgul ◽  
Nikolai Vatin ◽  
Ekaterina Aronova
Keyword(s):  
Power Systems ◽  
Electric Power ◽  
Power Supply ◽  
Optimal Solution ◽  
Weather Conditions ◽  
System Optimization ◽  
Energy System ◽  
Energy Performance ◽  
Electric Power Supply ◽  
Continuous Power

The article deals with the concept of solar photovoltaic systems use in power supply systems. An analysis of local solar resources potential has been carried out, and optimal orientation points of radiant heat absorbing photovoltaic panels have been chosen to achieve maximum energy performance. Simulation of electric power systems having different configurations has been implemented using the software program Homer. It has been stated that a combination of solar and diesel energy systems is considered to be an optimal solution under the weather conditions of Montenegro. The systems working together make it possible to reduce maintenance costs significantly and adjust capacity generation schedule with due account for energy consumption features to a maximum extent. This allows generating electric power at less cost and results in a more reliable and continuous power supply without failures for a consumer chosen.

scholarly journals Energy Performance Optimization in a Condensing Boiler

2021 ◽  
Vol 9 (1) ◽  
pp. 6
Author(s):  
Diego Fernández-Cheliz ◽  
Eloy Velasco-Gómez ◽  
Juan Peral-Andrés ◽  
Ana Tejero-González
Keyword(s):  
Energy Consumption ◽  
Natural Gas ◽  
Performance Optimization ◽  
Energy Performance ◽  
Primary Energy ◽  
Operating Conditions ◽  
Hot Water ◽  
Operating Parameters ◽  
Climate Conditions ◽  
Lower Heating Value

In Europe, primary energy consumption in buildings accounts for up to 25–40%, depending on the climate conditions. Space heating and Domestic Hot Water (DHW) contribute significantly to this energy consumption. Among the most common sources for heat generation in these appliances is natural gas. Condensing boilers can surpass the 100% energy performance over the lower heating value, if the operating conditions enable the water vapor in the exhaust gases to condensate. Consequently, optimizing the operating parameters of condensing boilers is necessary to decrease fuel consumption without hindering water heating needs. The present work presents an experimental approach to the operating parameters of a condensing boiler that works with natural gas. The aim is to develop a theoretical model that relates the energy performance to the water temperature set by the final user and the excess air set by the maintenance staff.

scholarly journals Energetic, Economic and Environmental (3E) Assessment and Design of Solar-Powered HVAC Systems in Pakistan

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4333
Author(s):  
Sajid Mehmood ◽  
Serguey A. Maximov ◽  
Hannah Chalmers ◽  
Daniel Friedrich
Keyword(s):  
Primary Energy ◽  
Simulation Software ◽  
Field Size ◽  
Monthly Basis ◽  
Rapid Urbanization ◽  
Cooling Systems ◽  
Climate Conditions ◽  
Capital Costs ◽  
Solar Field ◽  
Vapour Compression

Rapid urbanization, global warming and enhanced quality of life have significantly increased the demand of indoor thermal comfort and air conditioning systems are not a luxury anymore, but a necessity. In order to fulfil this need, it is imperative to develop affordable and environmentally friendly cooling solutions for buildings. In this work, the 3E performance (energetic, economic and environmental) of electrically driven water-cooled vapour compression systems and thermally (solar) driven vapour absorption cooling systems are evaluated and the parameters affecting the performance of solar-driven vapour absorption systems are investigated. The energy simulation software TRNSYS is used to simulate the performance of both systems in order to fulfil the cooling needs of an industrial manufacturing building for the typical climate conditions for Lahore, Pakistan. Primary energy saving, initial investment, operational cost, and carbon footprint indices are used to analyse the performance of both systems. In addition, a parametric code is written in Python and linked with TRNSYS to perform a parametric study to investigate the effects of various parameters such as solar field size, storage tank volume, optimum annual and monthly collector angles, and flow rate in the solar field on the solar-driven vapour absorption chiller performance. The results reveal that around 5% more energy can be absorbed per collector surface area by changing the solar tilt angle on a monthly basis compared to one fixed angle. The analysis shows that electrically driven vapour compression-based cooling systems have much higher running cost and are potentially hazardous for the environment but have lower capital costs. On the other hand, solar thermal systems have lower running costs and emissions but require further reductions in the capital costs or government subsidies to make them viable.

Comparative Study of Solar Assisted Cooling Technologies for Two Different Climates

2014 ◽  
Author(s):  
Andrés Montero ◽  
Jesús López-Villada ◽  
Carlos Naranjo-Mendoza ◽  
Jerko Labus
Keyword(s):  
Energy Performance ◽  
Primary Energy ◽  
Base Temperature ◽  
Absorption Chiller ◽  
Software Environment ◽  
Climate Conditions ◽  
Dynamic Cooling ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube ◽  
Different Climates

This study describes the influence of climate conditions and different solar assisted absorption technologies on the energy performance of air-conditioning systems. The correlation between dynamic cooling load profile and the performance of various solar assisted absorption system configurations was analyzed for two different climates: a hot-summer Mediterranean climate (Seville, Spain) and a tropical savannah climate (Guayaquil, Ecuador). A generic two-story office building was selected as a case study. The building fabrics are set to comply with the best practices of the two countries and the building counts with a useful area of 1152 m2 for the solar system installation. The hourly cooling demand for the building was calculated by using a simplified calculation method based on degree-days with variable base temperature. Three different solar assisted absorption configurations were simulated in TRNSYS software environment based on three types of solar collectors: evacuated tube collectors, parabolic trough collectors and linear Fresnel collectors (micro-concentrator type). The first configuration which involves evacuated tube collectors was coupled to a single-effect H2O-LiBr absorption chiller, while the other two configurations include double-effect H2O-LiBr absorption chiller. Models of two different absorption chillers were developed based on the characteristic equation method (ΔΔt). The comparison between the configurations was based on the primary energy analysis and CO2 emission.

scholarly journals Standardization of green building technologies: Nearly Zero-Energy Buildings (nZEB)

Tehnika ◽  
2021 ◽  
Vol 76 (2) ◽  
pp. 246-253
Author(s):  
Igor Milović
Keyword(s):  
Large Scale ◽  
Green Building ◽  
Energy Performance ◽  
Primary Energy ◽  
Common Denominator ◽  
Zero Energy ◽  
Climate Conditions ◽  
Policies And Measures ◽  
Energy Factors ◽  
Zero Energy Buildings

European legislation EPBD [1] (Energy Performance of Buildings Directive) makes nearly Zero-Energy Buildings (nZEBs) a standard by 2020. The technology is already available and proven; however, the large-scale uptake of nZEB construction and renovation will be a big challenge for all market actors and stakeholders involved. A substantial gap in reliable data on current market activities makes it difficult for policy-makers to evaluate the success of their policies and measures [2]. As concrete numeric thresholds or ranges are not defined in the EPBD, these requirements let a lot of space for own interpretation and thus allow Member States (MSs) to define their nZEB in a very flexible way taking into account their country specific climate conditions, primary energy factors, ambition levels, calculation methodologies and building traditions. This is also the main reason why existing nZEB definitions differ significantly from country to country. It is thus a challenging task to find a common denominator for defining an nZEB on a European scale [1,2].

scholarly journals Analysis of a Residential Photovoltaic-Thermal (PVT) System in Two Similar Climate Conditions

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3595 ◽  
Author(s):  
Madalina Barbu ◽  
George Darie ◽  
Monica Siroux
Keyword(s):  
Energy Saving ◽  
Energy Production ◽  
Weather Conditions ◽  
Energy System ◽  
Primary Energy ◽  
Assessment Method ◽  
Energy Output ◽  
Background Information ◽  
Climate Conditions ◽  
Time Of Year

Photovoltaic-thermal (PVT) panels combine solar thermal and photovoltaic technologies and generate simultaneously both heat and electricity. This paper looks at the potential of integrating these systems into small domestic prosumer households for the climates of Bucharest, Romania, and Strasbourg, France. First, some brief background information on PVT systems and the concept of prosumers is introduced, highlighting their features as well as the solar energy market setting in Romania and France. Next, a PVT system is proposed for a given household consumer in Strasbourg and Bucharest with the variable weather conditions corresponding to the two locations. The PVT system and the coupled consumer are modelled in TRNSYS (v17, Thermal Energy System Specialists, Madison, USA). A performance analysis is carried out in order to establish the daily instantaneous energy output and the annual energy production. The results indicate a 10–12% better performance in Bucharest compared to Strasbourg due to slightly better weather conditions. The system efficiency was assessed through various methods (first law efficiency and primary energy saving). Depending on the method used, the location and time of year, the results vary from 15% for the first law efficiency to 90% for the primary energy saving efficiency. The most suitable efficiency assessment method for this study was found to be the primary energy saving method, as it takes into account the regional differences in energy production. This study concludes that the Romanian PVT market has a good potential for adopting the technology, especially since it is currently less mature than in France.

Prospects of spring wheat cultivation in the conditions of arid Volga region

2020 ◽  
pp. 28-33
Author(s):  
Valery Genadievich Popov ◽  
Andrey Vladimirovich Panfilov ◽  
Yuriy Vyacheslavovich Bondarenko ◽  
Konstantin Mikhailovich Doronin ◽  
Evgeny Nikolaevih Martynov ◽  
...  
Keyword(s):  
Spring Wheat ◽  
Soil Layer ◽  
Weather Conditions ◽  
Volga Region ◽  
Mineral Fertilizers ◽  
Climate Conditions ◽  
Wheat Cultivation ◽  
Forest Belts ◽  
Clear Differentiation ◽  
The Impact

The article analyzes the experience of the impact of the system of forest belts and mineral fertilizers on the yield of spring wheat, including on irrigated lands. Vegetation irrigation is designed to maintain the humidity of the active soil layer from germination to maturation at the lower level of the optimum-70-75%, and in the phases of tubulation-earing - flowering - 75-80% NV. However, due to the large differences in zones and microzones of soil and climate conditions and due to the weather conditions of individual years, wheat irrigation regimes require a clear differentiation. In the Volga region in the dry autumn rainfalls give the norm of 800-1000 m3/ha, and in saline soils – 1000-1300 and 3-4 vegetation irrigation at tillering, phases of booting, earing and grain formation the norm 600-650 m3/ha. the impact of the system of forest belts, mineral fertilizers on the yield of spring wheat is closely tied to the formation of microclimate at different distances from forest edges.

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