scholarly journals On Preheating of the Outdoor Ventilation Air

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 15 ◽  
Author(s):  
Anna Romanska-Zapala ◽  
Mark Bomberg ◽  
Miroslaw Dechnik ◽  
Malgorzata Fedorczak-Cisak ◽  
Marcin Furtak
Keyword(s):  
Heat Exchanger ◽  
Heat Storage ◽  
Weather Conditions ◽  
Heating System ◽  
Additional Treatment ◽  
Integrated System ◽  
Missing Information ◽  
Geothermal Heat ◽  
The Earth ◽  
Air Intake

The growing popularity of buildings with integrated sub-systems requires a review of methods to optimize the preheating of ventilation air. An integrated system permits using geothermal heat storage parallel to the direct outdoor air intake with additional treatment in the mechanical room as a part of building an automatic control system. The earth–air heat exchanger (EAHX) has many advantages but also has many unanswered questions. Some of the drawbacks are: A possible entry of radon gas, high humidity in the shoulder seasons, and the need for two different air intake sources with a choice that depends on the actual weather conditions. In winter the EAHX may be used continuously to ensure thermal comfort, while in other seasons its operation must be automatically controlled. To generate missing information about EAHX technology we examined two nearly identical EAHX systems, one placed in the ground next to a building and the other under the basement slab. In another project, we reinforced the ground storage action by having a heat exchanger placed on the return pipes of the hydronic heating system. The information provided in this paper shows advantages of merging both these approaches, while the EAHX could be placed under the house or near the basement foundation that is using an exterior basement insulation.

scholarly journals On Preheating of the Outdoor Ventilation Air

2019 ◽  
Author(s):  
Anna Romanska-Zapala ◽  
Mark Bomberg ◽  
Miroslaw Dechnik ◽  
Malgorzata Fedorczak-Cisak ◽  
Marcin Furtak
Keyword(s):  
Heat Exchanger ◽  
Heat Storage ◽  
Weather Conditions ◽  
Heating System ◽  
Additional Treatment ◽  
Integrated System ◽  
Outdoor Air ◽  
Missing Information ◽  
Geothermal Heat ◽  
Air Intake

Growing popularity of buildings with integrated sub-systems, requires a review of methods to optimize the preheat of ventilation air. An integrated system permits using geothermal heat storage parallel to the direct outdoor air intake with additional treatment in the mechanical room as a part of building automatic control system. Earth Air Heat Exchanger (EAHX) has many advantages but also has many unanswered questions. Some of the drawbacks are: a possible entry of radon gas, high humidity in the shoulder seasons as well as the need for two different air intake sources with a choice that depends on the actual weather conditions. While in winter, the EAHX may be used continuously to ensure thermal comfort, in other seasons, its operation must be automatically controlled. To generate the missing information about the EAHX technology we have examined two nearly identical EAHX systems, one placed in ground next to the building and the other under the basement slab. In another project, we have reinforced the ground storage action by heat exchanger placed on the return pipes of the hydronic heating system. Effectively, the information provided in this paper, shows advantages of merging both these approaches while the EAHX could be placed under the house or near the basement foundation that is using an exterior basement insulation.

scholarly journals Alternative Methods For Preheating Outdoor Ventilation Air

2019 ◽  
Author(s):  
Anna Romanska - Zapala Romanska - Zapala ◽  
Mark Bomberg ◽  
Miroslaw Dechnik ◽  
Malgorzata Fedorczak-Cisak ◽  
Marcin Furtak
Keyword(s):  
Heat Exchanger ◽  
Thermal Comfort ◽  
Weather Conditions ◽  
Integrated System ◽  
Alternative Methods ◽  
High Humidity ◽  
Exterior Wall ◽  
Missing Information ◽  
The Earth ◽  
Air Intake

Growing popularity of smart and integrated buildings requires a review of methods to optimize the preheat of ventilation air. An integrated system permits using heat ex-changers located in the mechanical room or in the future even using an exterior wall as a heat exchanger. One may ask the question how does the earth-air heat exchanger (EAHX) technology fitts into this function. EAHX has many advantages but also has many unanswered questions. Some of the drawbacks are: a possible entry of radon gas, high humidity in the shoulder seasons as well as the need for two different air intake sources with a choice that depends on the actual weather conditions. While in winter, the EAHX may be used continuously to ensure thermal comfort, in other seasons, its operation must be automatically controlled. To generate the missing information about the EAHX technology we reviewed literature and examined two nearly identical EAHX systems, placed either in ground next to the building or under the basement slab. Effectively, the information provided in this paper, shows advantages of merging both these approaches while the EAHX shoud be placed under the house or near the basement foundation.

scholarly journals ON INTEGRATED HEATING, VENTILATION AND AIR CONDITIONING SYSTEMS IN ROOMS OF SHOPPING CENTERS

2020 ◽  
Vol 3 (4) ◽  
pp. 39-47
Author(s):  
T. Il'ina ◽  
M. Kolesnikov ◽  
I. Kryukov
Keyword(s):  
Heat Exchanger ◽  
Air Conditioning ◽  
Heating System ◽  
Engineering Calculation ◽  
Integrated System ◽  
Thermal Engineering ◽  
Shopping Centers ◽  
Water Heating ◽  
Air Heating ◽  
Gas Burner

the paper considers a method for creating microclimate parameters in the rooms of shopping centers, sports complexes, etc. The possibility of using a complex system including air heating, ventilation and air conditioning is shown on the example of a shopping hall. To improve the efficiency of the system, it is proposed to replace traditional water heating with air heating, which works by using a gas burner-heat exchanger. For the rooms of a shopping center in the city of Saint Petersburg, the thermal engineering calculation of external fences was performed, and the heat capacity of the heating system was determined. Based on the results of the heat and air balance of the grocery shopping area, the performance of the ventilation and air conditioning system is calculated. An autonomous monoblock unit for air treatment was selected. During the cold period, the unit performs the functions of air heating and ventilation. Air recirculation is provided to save heat energy. The amount of outdoor and recirculating air is calculated. During the warm period, air is cooled and dehumidified by using a compression refrigeration cycle. The proposed integrated system for creating the required parameters of the microclimate allows reducing material costs by using a gas burner-heat exchanger instead of a heat point for water heating, as well as using a cheaper energy source and heat recovery through a heat pump.

scholarly journals Exergy analysis of the performance of low-temperature district heating system with geothermal heat pump

2014 ◽  
Vol 35 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Robert Sekret ◽  
Anna Nitkiewicz
Keyword(s):  
Heat Exchanger ◽  
Low Temperature ◽  
Heat Pump ◽  
Exergy Analysis ◽  
Heating System ◽  
Total System ◽  
Exergy Destruction ◽  
Geothermal Heat ◽  
District Heating System ◽  
Absorption Heat Pump

Abstract Exergy analysis of low temperature geothermal heat plant with compressor and absorption heat pump was carried out. In these two concepts heat pumps are using geothermal water at 19.5 oC with spontaneous outflow 24 m3/h as a heat source. The research compares exergy efficiency and exergy destruction of considered systems and its components as well. For the purpose of analysis, the heating system was divided into five components: geothermal heat exchanger, heat pump, heat distribution, heat exchanger and electricity production and transportation. For considered systems the primary exergy consumption from renewable and non-renewable sources was estimated. The analysis was carried out for heat network temperature at 50/40 oC, and the quality regulation was assumed. The results of exergy analysis of the system with electrical and absorption heat pump show that exergy destruction during the whole heating season is lower for the system with electrical heat pump. The exergy efficiencies of total system are 12.8% and 11.2% for the system with electrical heat pump and absorption heat pump, respectively.

scholarly journals Alternative Methods for Preheating Outdoor Ventilation Air

2019 ◽  
Author(s):  
Anna Romanska-Zapala ◽  
Mark Bomberg ◽  
Miroslaw Dechnik ◽  
Malgorzata Fedorczak-Cisak ◽  
Marcin Furtak
Keyword(s):  
Heat Exchangers ◽  
Weather Conditions ◽  
Integrated System ◽  
Alternative Methods ◽  
Steering Control ◽  
Temperature Changes ◽  
Air Intake ◽  
Complex Technology ◽  
The One ◽  
Integrated System Design

In the pursuit of energy efficiency one has developed a complex technology of earth-air heat exchangers (EAHX). In this process, one discovered some drawbacks such as possible entry of radon gas or high humidity in the shoulder seasons. Elsewhere, we highlighted that when the outdoor temperature changes frequently, one needs using two different air intake sources with an automatic selection of the one more appropriate for the actual weather conditions. In winter, the EAHX may be used continually but in the other seasons, the selection should be performed by a steering/ control system. In this paper examined two nearly identical EAHX systems placed in the soil next to the building or under the basement slab. While there is an advantage in the under house placement, yet the advent of integrated system design permits replacing the EAHX by different heat exchangers located in the mechanical room (as it was done in a case study in NY) or in the exterior wall. In the latter case we propose an alternative system that permits using different ventilation patterns in summer and winter.

Biogeochemical Cycles and Climate

2019 ◽  
Author(s):  
Han Dolman
Keyword(s):  
Ocean Circulation ◽  
Biogeochemical Cycles ◽  
Integrated System ◽  
General Introduction ◽  
Complex Interplay ◽  
Climate Agreements ◽  
Mitigation And Adaptation ◽  
The Earth ◽  
Geological Past ◽  
Recent Climate

This book describes the interaction of the main biogeochemical cycles of the Earth and the physics of climate. It takes the perspective of Earth as an integrated system and provides examples of both changes in the current climate and those in the geological past. The first three chapters offer a general introduction to the context of the book, outlining the climate system as a complex interplay between biogeochemistry and physics and describing the tools available for understanding climate: observations and models. These chapters describe the basics of the system, the rates and magnitudes and the crucial aspects of biogeochemical cycles needed to understand their functioning. The second part of the book consists of four chapters that describe the physics required to understand the interaction of the climate with biogeochemistry and change. These chapters describe the physics of radiation, and that of the atmosphere, ocean circulation and thermodynamics. The interaction of aerosols with radiation and clouds is addressed in an additional chapter. The third part of the book deals with Earth’s (bio)geochemical cycles. These chapters focus on the stocks and fluxes of the main reservoirs of Earth’s biogeochemical cycles—atmosphere, land and ocean—and their role in the cycles of carbon, oxygen, nitrogen, iron, phosphorus, oxygen, sulphur and water, as well as their interactions with climate. The final two chapters describe possible mitigation and adaptation actions, in relation to recent climate agreements, but always with an emphasis on the biogeochemical aspects.

scholarly journals Scaling in a Geothermal Heat Exchanger at Soultz-Sous-Forêts (Upper Rhine Graben, France): A XRD and SEM-EDS Characterization of Sulfide Precipitates

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 271
Author(s):  
Béatrice A. Ledésert ◽  
Ronan L. Hébert ◽  
Justine Mouchot ◽  
Clio Bosia ◽  
Guillaume Ravier ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Energy Production ◽  
Electricity Production ◽  
Normal Operation ◽  
Upper Rhine Graben ◽  
Geothermal Heat ◽  
Deep Wells ◽  
Upper Rhine ◽  
Management Issues

The Soultz-Sous-Forêts geothermal site (France) operates three deep wells for electricity production. During operation, scales precipitate within the surface installation as (Ba, Sr) sulfate and (Pb, As, Sb) sulfide types. Scales have an impact on lowering energy production and inducing specific waste management issues. Thus scaling needs to be reduced for which a thorough characterization of the scales has to be performed. The geothermal brine is produced at 160 °C and reinjected at 70 °C during normal operation. In the frame of the H2020 MEET project, a small heat exchanger was tested in order to allow higher energy production, by reinjecting the geothermal fluid at 40 °C. Samples of scales were analyzed by XRD and SEM-EDS, highlighting that mostly galena precipitates and shows various crystal shapes. These shapes can be related to the turbulence of the flow and the speed of crystal growth. Where the flow is turbulent (entrance, water box, exit), crystals grow quickly and mainly show dendritic shape. In the tubes, where the flow is laminar, crystals grow more slowly and some of them are characterized by well-developed faces leading to cubes and derived shapes. The major consequence of the temperature decrease is the increased scaling phenomenon.

scholarly journals Effect of Twisted Fin Array in a Triple-Tube Latent Heat Storage System during the Charging Mode

2021 ◽  
Vol 13 (5) ◽  
pp. 2685
Author(s):  
Mohammad Ghalambaz ◽  
Jasim M. Mahdi ◽  
Amirhossein Shafaghat ◽  
Amir Hossein Eisapour ◽  
Obai Younis ◽  
...  
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Latent Heat ◽  
Thermal Energy ◽  
Heat Storage ◽  
Hot Water ◽  
Melting Time ◽  
Latent Heat Storage ◽  
Tube Heat Exchanger ◽  
Storage Rate

This study aims to assess the effect of adding twisted fins in a triple-tube heat exchanger used for latent heat storage compared with using straight fins and no fins. In the proposed heat exchanger, phase change material (PCM) is placed between the middle annulus while hot water is passed in the inner tube and outer annulus in a counter-current direction, as a superior method to melt the PCM and store the thermal energy. The behavior of the system was assessed regarding the liquid fraction and temperature distributions as well as charging time and energy storage rate. The results indicate the advantages of adding twisted fins compared with those of using straight fins. The effect of several twisted fins was also studied to discover its effectiveness on the melting rate. The results demonstrate that deployment of four twisted fins reduced the melting time by 18% compared with using the same number of straight fins, and 25% compared with the no-fins case considering a similar PCM mass. Moreover, the melting time for the case of using four straight fins was 8.3% lower than that compared with the no-fins case. By raising the fins’ number from two to four and six, the heat storage rate rose 14.2% and 25.4%, respectively. This study presents the effects of novel configurations of fins in PCM-based thermal energy storage to deliver innovative products toward commercialization, which can be manufactured with additive manufacturing.

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