scholarly journals Unified Methodology to Identify the Potential Application of Seasonal Sorption Storage Technology

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1037 ◽  
Author(s):  
Andrea Frazzica ◽  
Vincenza Brancato ◽  
Belal Dawoud
Keyword(s):  
Distribution Systems ◽  
Heating System ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Working Fluid ◽  
Space Heating ◽  
Preliminary Evaluation ◽  
Multi Wall Carbon Nanotubes ◽  
Sorbent Materials ◽  
Definition Of

In this study, the definition of a new methodology for a preliminary evaluation of the working boundary conditions under which a seasonal thermal energy storage (STES) system operates is described. The approach starts by considering the building features as well as the reference heating system in terms of solar thermal collectors’ technology, ambient heat sinks/source, and space heating distribution systems employed. Furthermore, it is based on a deep climatic analysis of the place where the STES needs to be installed, to identify both winter and summer operating conditions. In particular, the STES energy density is evaluated considering different space heating demands covered by the STES (ranging from 10% up to 60%). The obtained results demonstrate that this approach allows for the careful estimation of the achievable STES density, which is varies significantly both with the space heating coverage guaranteed by the STES as well as with the ambient heat source/sink that is employed in the system. This confirms the need for careful preliminary analysis to avoid the overestimation of the STES material volume. The proposed approach was then applied for different climatic conditions (e.g., Germany and Sweden) and the volume of one of the most attractive composite sorbent materials reported in the literature, i.e., multi-wall carbon nanotubes (MWCNT)-LiCl, using water as the working fluid, needed for covering the variable space heating demand in a Nearly Zero Energy Building (NZEB) was calculated. In the case of Swedish buildings, it ranges from about 3.5 m3 when 10% of the space heating demand is provided by the STES, up to 11.1 m3 when 30% of the space heating demand is provided by the STES.

The Study of Heat Consumption Systems of Buildings with Heat Pump

2016 ◽  
Vol 856 ◽  
pp. 297-302 ◽  
Author(s):  
Anna Tsynaeva ◽  
Katerina Tsynaeva
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
Heating System ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Heat Consumption ◽  
Low Grade ◽  
Consumption System ◽  
Low Grade Heat

Systems of heat consumption of the building with heat pump that uses low-grade heat source are investigated. Effectiveness of heat consumption systems with heat pump is concluded effective for severe climatic conditions prevailing in Russia. Characteristics of heat consumption system with heat pump and the traditional heating system are compared. In this case the heat pump is used the warmth of the environment, that is why considered operating conditions for the autumn and spring. Low inertia of heat systems with heat pump compared to traditional ones during autumn and spring proved.

scholarly journals Validated TRNSYS Model for Solar Assisted Space Heating System

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Nidal Abdalla
Keyword(s):  
Residential Building ◽  
Heating System ◽  
Operating Conditions ◽  
Space Heating ◽  
Solar Fraction ◽  
Heating Load ◽  
Solar House ◽  
Long Term Performance ◽  
Google Sketchup ◽  
Term Performance

The present study involves a validated TRNSYS model for solar assisted space heating system as applied to a residential building in Jordan using new detailed radiation models of the TRNSYS 17.1 and geometric building model Trnsys3d for the Google SketchUp 3D drawing program. The annual heating load for a building (Solar House) which is located at the Royal Scienti?c Society (RS5) in Jordan is estimated under climatological conditions of Amman. The aim of this Paper is to compare measured thermal performance of the Solar House with that modeled using TRNSYS. The results showed that the annual measured space heating load for the building was 6,188 kWh while the heati.ng load for the modeled building was 6,391 kWh. Moreover, the measured solar fraction for the solar system was 50% while the modeled solar fraction was 55%. A comparison of modeled and measured data resulted in percentage mean absolute errors for solar energy for space heating, auxiliary heating and solar fraction of 13%, 7% and 10%, respectively. The validated model will be useful for long-term performance simulation under different weather and operating conditions.

scholarly journals A Compact Thermally Driven Cooling System Based on Metal Hydrides

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2482 ◽  
Author(s):  
Christoph Weckerle ◽  
Marius Dörr ◽  
Marc Linder ◽  
Inga Bürger
Keyword(s):  
Internal Combustion Engines ◽  
Cooling System ◽  
Heating System ◽  
Operating Conditions ◽  
Specific Power ◽  
Working Fluid ◽  
Cooling Power ◽  
Half Cycle ◽  
Exhaust Heat ◽  
Thermally Driven

Independent of the actual power train, efficiency and a high driving range in any weather conditions are two key requirements for future vehicles. Especially during summertime, thermally driven air conditioning systems can contribute to this goal as they can turn the exhaust heat of internal combustion engines, fuel cells or of any additional fuel-based heating system into a cooling effect. Amongst these, metal hydride cooling systems (MHCSs) promise very high specific power densities due to the short reaction times as well as high reaction enthalpies. Additionally, the working fluid hydrogen has a very low global warming potential. In this study, the experimental results of a compact and modular MHCS with a specific cooling power of up to 585 W kg MH − 1 referred to one cold generating MH are presented, while reactor and MH weight in total is less than 30 kg and require a volume < 20 dm3. The system is driven by an auxiliary fuel heating system and its performance is evaluated for different operating conditions, e.g., temperature levels and half-cycle times. Additionally, a novel operation optimization of time-shifted valve switching to increase the cooling power is implemented and investigated in detail.

Energy Performance of School Buildings by Construction Periods in Federation of Bosnia and Herzegovina

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 42
Author(s):  
Dragan Katić ◽  
Hrvoje Krstić ◽  
Saša Marenjak
Keyword(s):  
Bosnia And Herzegovina ◽  
Heating System ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Space Heating ◽  
School Buildings ◽  
Energy Costs ◽  
Improve Energy Efficiency ◽  
Construction Periods

This paper is part of broader research aimed at determining the relationship between energy performance and energy costs as a part of the operational and life cycle costs in school buildings in the Federation of Bosnia and Herzegovina (FBiH), as exceptionally important social and public buildings. The research was conducted by statistical analysis of data collected from documents of detailed energy audits (DEA) for 185 school buildings in FBiH in relation to construction periods. The paper analyzes the characteristics of buildings such as construction period, building envelope characteristics, climatic conditions, efficiency of installed space heating system, number of users and heating mode. The aim of this research was to determine the energy performance for the existing state and to compare them with the allowable values in accordance with the applicable legal regulations. There is a performance gap between predicted (calculated) and measured (actual) delivered energy for space heating. This research shows poor energy performance and provides a basis for developing strategies and plans to improve energy efficiency. The results of the energy performance of school buildings in the FBiH are the first step towards the development of a model for predicting energy costs.

STUDY OF SPLIT-SYSTEM IN HEATING MODE

2015 ◽  
Vol 5 (1) ◽  
pp. 90-99
Author(s):  
Alinya O. KARTASHOVA ◽  
Daria O. KORTYAEVA ◽  
Ksenia E. KULYASOVA ◽  
Anna A. TSYNAEVA
Keyword(s):  
Heat Pump ◽  
Indoor Environment ◽  
Heating System ◽  
Operating Conditions ◽  
Mode Analysis ◽  
Working Fluid ◽  
Heating Mode ◽  
The Impact ◽  
System Operating ◽  
Split System

In this article there is a study of the heat pump for heating the premises of a public building (academic building of Samara State University of Architecture and Civil Engineering). The aim of the work was to determine the parameters of the heat pump and the impact of his work on the microclimate parameters of heated space. As the heat pump was activated split-system, operating in the heating mode; analysis was performed changing the state of the working fluid (Freon-R410A) used in this split-system. The studies revealed that the use of the heat pump (split system, operating in heating mode) allows you to maintain optimum parameters of the indoor environment. With the help of the tests revealed that the use of split-system as a heating system reduces the inertia of the system to ensure the indoor environment. This leads to maintain a comfortable environment for human habitation when the external operating conditions typical of the autumn-spring period, and demonstrates the effectiveness of the use of split systems, the use of which may in residential and public buildings. Furthermore, was prepared a graph of the room temperature before and after the operation of a split system.

HELIOTHERAPY IN THE TREATMENT OF PSORIATIC ARTHRITIS

2018 ◽  
Vol 28 (2) ◽  
pp. 483-487
Author(s):  
Snezhina Georgieva ◽  
Dilyana Zvezdova
Keyword(s):  
Psoriatic Arthritis ◽  
Clinical Picture ◽  
Local Therapy ◽  
Severe Form ◽  
Climatic Conditions ◽  
Joint Disease ◽  
Immune Mediated ◽  
Social Comfort ◽  
Pigment Type ◽  
Definition Of

Psoriatic arthritis is an inflammatory joint disease associated with psoriasis vulgaris, with routinely negative rheumatoid factors and the absence of rheumatoid nodules. This is an immune-mediated disease, according to generally accepted definition of Wright and Moll from 1973. American Association against Rheumatism classified psoriatic arthritis as an independent disease in 1964. Psoriatic arthritis is a single disease with a varied clinical picture. It belongs to the group of seronegative spondyloarthropathies with which there are general clinical features. It is believed that similar mechanisms determine the onset of psoriasis and psoriatic arthritis. The clinical picture includes various clinical forms that damage the peripheral and sacroiliac joints, spine, internal organs. The treatment of psoriatic arthritis is directed simultaneously to the influence of skin and joint changes. Purpose: Our study aims to summarize our long-standing experience in the treatment of psoriatic arthritis with heliotherapy. Subject of observation: Monitoring includes 132 patients with moderate and severe form of psoriasis treated at the sanatorium in town of Pomorie for 5 years in the period 2001-2006. Results and discussion: 132 patients with psoriasis with no effect on the local therapy and have proven psoriatic arthritis were selected. In our climatic conditions, heliotherapy is appointed during the warm half-year. Sun treatment was conducted under the conditions of a healing beach, which had shielding, radiation-protective devices. In patients with erythema - pigment and pigment type skin reactivity begins with 1-2 bioadoses reached to 8-10 biodoses, carried out in the area of overcomfort. Conclusion: The studies demonstrated that heliotherapy combined with medications significantly improves the prognosis of patients with this disease. The ultimate success would mean overcoming the frequent depression conditions, better survival and social comfort for patients with psoriatic arthritis.

First and Second Law Analysis of a Flat Plate Collector Working With Nanofluids

2018 ◽  
Author(s):  
M. T. Nitsas ◽  
I. P. Koronaki ◽  
L. Prentza
Keyword(s):  
Flat Plate ◽  
Second Law Of Thermodynamics ◽  
Climatic Conditions ◽  
Working Fluid ◽  
Second Law ◽  
Inlet Temperature ◽  
Water Tank ◽  
Systems Quality ◽  
Typical Day ◽  
Flat Plate Collector

The utilization of solar energy in thermal energy systems was and always be one of the most effective alternative to conventional energy resources. Energy efficiency is widely used as one of the most important parameters in order to evaluate and compare thermal systems including solar collectors. Nevertheless, the first law of thermodynamics is not solely capable of describing the quantitative and qualitative performance of such systems and thus exergy efficiency is used so as to introduce the systems’ quality. In this work, the performance of a flat plate solar collector using water based nanofluids of different nanoparticle types as a working fluid is analyzed theoretically under the climatic conditions in Greece based on the First and Second Law of Thermodynamics. A mathematical model is built and the model equations are solved iteratively in a MATLAB code. The energy and exergy efficiencies as well as the collector losses coefficient for various parameters such as the inlet temperature, the particles concentration and type are determined. Moreover, a dynamic model is built so as to determine the performance of a flat plate collector working with nanofluids and the useful energy that can be stored in a water tank. The exergy destruction and exergy leakage are determined for a typical day in summer during which high temperatures and solar intensity values are common for the Greek climate.

scholarly journals Large Eddy Simulations of Strongly Non-Ideal Compressible Flows through a Transonic Cascade

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 772
Author(s):  
Jean-Christophe Hoarau ◽  
Paola Cinnella ◽  
Xavier Gloerfelt
Keyword(s):  
Compressible Flows ◽  
Flow Behavior ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Ideal Gas ◽  
Operating Conditions ◽  
Large Eddy Simulations ◽  
Working Fluid ◽  
Viscous Effects ◽  
Large Eddy

Transonic flows of a molecularly complex organic fluid through a stator cascade were investigated by means of large eddy simulations (LESs). The selected configuration was considered as representative of the high-pressure stages of high-temperature Organic Rankine Cycle (ORC) axial turbines, which may exhibit significant non-ideal gas effects. A heavy fluorocarbon, perhydrophenanthrene (PP11), was selected as the working fluid to exacerbate deviations from the ideal flow behavior. The LESs were carried out at various operating conditions (pressure ratio and total conditions at inlet), and their influence on compressibility and viscous effects is discussed. The complex thermodynamic behavior of the fluid generates highly non-ideal shock systems at the blade trailing edge. These are shown to undergo complex interactions with the transitional viscous boundary layers and wakes, with an impact on the loss mechanisms and predicted loss coefficients compared to lower-fidelity models relying on the Reynolds-averaged Navier–Stokes (RANS) equations.

scholarly journals Sensitivity Analysis of OTEC-CC-MX-1 kWe Plant Prototype

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2585
Author(s):  
Jessica Guadalupe Tobal-Cupul ◽  
Estela Cerezo-Acevedo ◽  
Yair Yosias Arriola-Gil ◽  
Hector Fernando Gomez-Garcia ◽  
Victor Manuel Romero-Medina
Keyword(s):  
Sensitivity Analysis ◽  
Experimental Tests ◽  
Caribbean Sea ◽  
Ocean Model ◽  
Operating Conditions ◽  
Working Fluid ◽  
Ocean Energy ◽  
Mexican Caribbean ◽  
Water Temperature Data ◽  
Mass Flows

The Mexican Caribbean Sea has potential zones for Ocean Thermal Energy Conversion (OTEC) implementation. Universidad del Caribe and Instituto de Ciencias del Mar y Limnologia, with the support of the Mexican Centre of Innovation in Ocean Energy, designed and constructed a prototype OTEC plant (OTEC-CC-MX-1 kWe), which is the first initiative in Mexico for exploitation of this type of renewable energy. This paper presents a sensitivity analysis whose objective was to know, before carrying out the experimental tests, the behavior of OTEC-CC-MX-1 kWe regarding temperature differences, as well as the non-possible operating conditions, which allows us to assess possible modifications in the prototype installation. An algorithm was developed to obtain the inlet and outlet temperatures of the water and working fluid in the heat exchangers using the monthly surface and deep-water temperature data from the Hybrid Coordinate Ocean Model and Geographically Weighted Regression Temperature Model for the Mexican Caribbean Sea. With these temperatures, the following were analyzed: fluctuation of thermal efficiency, mass flows of R-152a and water and power production. By analyzing the results, we verified maximum and minimum mass flows of water and R-152a to produce 1 kWe during a typical year in the Mexican Caribbean Sea and the conditions when the production of electricity is not possible for OTEC-CC-MX-1 kWe.

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