Dynamic Modeling and Simulation of a Solar Air Heater Assisted by a Dehumidification System for an Agriculture Greenhouse

ASME 2020 Power Conference ◽

10.1115/power2020-16189 ◽

2020 ◽

Author(s):

Fahad Almehmadi ◽

Kevin Hallinan

Keyword(s):

Regression Model ◽

Energy Savings ◽

Energy Requirement ◽

Primary Energy ◽

Integrated System ◽

Solar Air Heater ◽

Plant Materials ◽

Air Heater ◽

Northern Latitudes ◽

The Impact

Abstract Appropriate greenhouse microclimate control is essential for optimizing plant growth and food production. But, maintenance of a greenhouse microclimate generally requires an excessive amount of energy. According to a report published by Scott Sanford [1], the energy cost for greenhouses is considered the third highest annual cost, behind labor and plant materials. At northern latitudes, heating is the primary energy requirement needed in an agriculture greenhouse, comprising 70 to 80% of a typical greenhouse energy consumption [1]. A reduction of heating energy is necessary to ensure the economic viability of a greenhouse. This research investigates the potential energy savings associated with integrating a solar air heater assisted with a desiccant wheel in an agriculture greenhouse. This study has two main thrusts. The first is to demonstrate the energy effectiveness a solar air heater with a dehumidification system to maintain the internal climate. The second thrust is to develop a multi-linear regression model that can be used to predict the hourly heating requirement. Thereafter, the developed regression model can be used to conduct a parametric analysis to investigate the impact of changing greenhouse parameters on the total heating requirements. A case study has been considered for a greenhouse that is 30 m long and 24 m wide. The climate condition of the city of Dayton, OH was selected for this case. The predicted performance of the integrated system is compared with two other heating systems: electric and gas furnaces. The study reveals that heating energy savings in the proposed system is 51% and 30% when compared with the electric and gas furnaces, respectively. Aside from heating energy savings, the proposed system can be efficiently used to control indoor humidity in a way that ensures better crop yield.

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Thermoelectric Generator–Integrated Solar Air Heater: A Compact Passive System

Journal of Energy Resources Technology ◽

10.1115/1.4048065 ◽

2020 ◽

Vol 143 (4) ◽

Author(s):

Kumar Venkateshwar ◽

Abu Raihan Mohammad Siddique ◽

Syeda Tasnim ◽

Hari Simha ◽

Shohel Mahmud

Keyword(s):

Thermoelectric Generator ◽

Energy Requirement ◽

Electrical Energy ◽

Cold Weather ◽

Space Heating ◽

Solar Air Heater ◽

Thermoelectric Generators ◽

Passive System ◽

Air Heater ◽

Operational Range

Abstract Solar air heater is a promising, economically viable, and matured technology for space heating and drying applications. One of the primary reasons for the limited usage of a solar air heater in developing countries is the unavailability of continuous electricity supply. Although the solar air heater is theoretically passive, practically electrical energy is required to achieve a steady airflow. Therefore, the unreliability of electricity forces people to rely on firewood for heat during the cold weather, which has severe effects on health and climate change. In the present work, the potential of thermoelectric generators (TEGs) to meet the electrical energy requirement of a solar air heater is studied. Two configurations, each with three different numbers of stages of TEGs, are analyzed. The effect of the integration of TEGs on the thermal performance of solar air heater is analyzed alongside the comparison between the electrical energy required by solar air heaters and electrical energy generated upon the integration of TEGs. A numerical model is developed in matlab and validated using the experimental results. One of the designs meets the electrical energy requirement of the fan in a wide operational range but lowers the process heat generation by approximately 1–6.25%. The electrical energy generated by the other design falls short of demand posed by the system in most operating range. However, the thermal energy generation is marginally higher compared to that of the conventional solar air heater.

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The effect of a density gradient in groundwater on ATES system efficiency and subsurface space use

Advances in Geosciences ◽

10.5194/adgeo-45-85-2018 ◽

2018 ◽

Vol 45 ◽

pp. 85-103

Author(s):

Martin Bloemendal ◽

Theo N. Olsthoorn

Keyword(s):

Thermal Energy ◽

Energy Savings ◽

Salinity Gradient ◽

Primary Energy ◽

Density Gradients ◽

Buoyancy Flow ◽

Heating And Cooling ◽

Vertical Hydraulic Conductivity ◽

The Impact ◽

Research Show

Abstract. A heat pump combined with Aquifer Thermal Energy Storage (ATES) has high potential in efficiently and sustainably providing thermal energy for space heating and cooling. This makes the subsurface, including its groundwater, of crucial importance for primary energy savings. ATES systems are often placed in aquifers in which salinity increases with depth. This is the case in coastal areas where also the demand for ATES application is high due to high degrees of urbanization in those areas. The seasonally alternating extraction and re-injection between ATES wells disturbs the preexisting ambient salinity gradient causing horizontal density gradients, which trigger buoyancy flow, which in turn affects the recovery efficiency of the stored thermal energy. This section uses analytical and numerical methods to understand and explain the impact of buoyancy flow on the efficiency of ATES in such situations, and to quantify the magnitude of this impact relative to other thermal energy losses. The results of this research show that losses due to buoyancy flow may become considerable at (a relatively large) ambient density gradients of over 0.5 kg m−3 m−1 in combination with a vertical hydraulic conductivity of more than 5 m day−1. Monowell systems suffer more from buoyancy losses than do doublet systems under similar conditions.

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Cogeneration Plant on Biomass - Case Study

The Scientific Bulletin of Electrical Engineering Faculty ◽

10.1515/sbeef-2017-0027 ◽

2018 ◽

Vol 18 (2) ◽

pp. 7-11 ◽

Cited By ~ 2

Author(s):

A. Enescu ◽

E. Diaconu

Keyword(s):

Energy Savings ◽

High Efficiency ◽

Primary Energy ◽

Hot Water ◽

Raw Material ◽

Cogeneration Plant ◽

The Social ◽

The One ◽

The Impact

AbstractThe concept of cogeneration defines the simultaneous production with the same installation of electric and thermal energy (in the form of hot water or steam). High-efficiency cogeneration implies that cogeneration production should ensure primary energy savings of at least 10% compared to the reference values of separate production of electricity and heat. This paper presents the process of functioning of a cogeneration plant, operating in the Suceava county, Romania, referring to the actual values regarding the consumption and the proportions of the raw material on the one hand and the energy produced on the other. It also describes the entire production process as well as the impact on the environment, the social and economic aspects of the implementation of such a project.

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Thermal enhancement of a building integrated photovoltaic/thermal system coupled with an air source heat pump

10.32920/ryerson.14653494.v1 ◽

2021 ◽

Author(s):

Edward Vuong

Keyword(s):

Heat Pump ◽

Energy Efficient ◽

Energy Savings ◽

Electricity Consumption ◽

Integrated System ◽

Space Heating ◽

Solar Air Heater ◽

Net Zero ◽

Building Integrated Photovoltaic ◽

The Hours

Enhancements of a building integrated photovoltaic/thermal (BIPV/T) system intended for coupling with an air source multispeed heat pump (MSHP) is presented. The systems were analyzed using a modified version of EnergyPlus, a quasi-steady state building energy simulation program. A sensitivity analysis of the internal channel surface and cover emissivity parameters of the Opaque BIPV/T, transparent BIPV/T, and building integrated solar air heater collectors (BISAH) was conducted. In addition, collector arrangement analyses were performed. A BIPV/T- BISAH array design was selected based on the results of the analyses and evaluated using a net-zero energy house and an energy efficient house. The integrated BIPV/T-BISAH coupled ASHP system reduced space heating electricity consumption of the net-zero house by 6.5% and the energy efficient house by 3.4%. These low levels of savings were largely due to the passive design of the houses that reduced heating loads during sunny hours; this resulted in a mismatch between the hours when the integrated system could provide energy savings and the need for space heating.

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Life Cycle Evaluation of Sustainable Practices in a Sauna Bath

Sustainability ◽

10.3390/su11205647 ◽

2019 ◽

Vol 11 (20) ◽

pp. 5647

Author(s):

Luis Velazquez ◽

Sandra Villalba ◽

Ricardo García ◽

Nora Munguía

Keyword(s):

Life Cycle ◽

Thermal Energy ◽

Material Selection ◽

Well Being ◽

Solar Air Heater ◽

Sustainable Solutions ◽

Air Heater ◽

Graphene Coating ◽

The Impact ◽

Selection Of

To battle climate change, the search for sustainable solutions and the reduction of environmental impacts are activities that must be pursued in all areas of human life. This study aimed to conduct a Life Cycle Evaluation of the environmental aspects and potential benefits associated with two different innovative adaptations to a sauna bath. The first adaptation is related to the selection of wooden materials for the bath’s interior construction; the second is related to the source of thermal energy. For the selection of wooden materials, experiments were performed to evaluate a graphene coating and its capacity to increase the durability of wooden materials. For the thermal energy source, a solar air heater was experimentally assessed to confirm its capacity to supply the thermal energy required to operate the sauna bath. Finally, the material selection and the heating operation were integrated in a Life Cycle Impact Assessment, contrasting two scenarios: “business as usual sauna bath” and “sustainable sauna bath.” The findings showed a significant reduction of around 61% of total emissions from the application of a solar air heater and wooden materials treated with a graphene coating. At the end of this study, “human well-being,” “ecosystems,” and “resources” were expressed in monetary values to assess the impact of the above practices in a sauna bath.

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Thermal enhancement of a building integrated photovoltaic/thermal system coupled with an air source heat pump

10.32920/ryerson.14653494 ◽

2021 ◽

Author(s):

Edward Vuong

Keyword(s):

Heat Pump ◽

Energy Efficient ◽

Energy Savings ◽

Electricity Consumption ◽

Integrated System ◽

Space Heating ◽

Solar Air Heater ◽

Net Zero ◽

Building Integrated Photovoltaic ◽

The Hours

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Ease of Doing Business and Its Impact on Inward FDI

Indonesian Journal of Management and Business Economics ◽

10.32455/ijmbe.v1i1.52 ◽

2018 ◽

Vol 1 (1) ◽

pp. 52 ◽

Cited By ~ 2

Author(s):

Mohamed Tareq Hossain ◽

Zubair Hassan ◽

Sumaiya Shafiq ◽

Abdul Basit

Keyword(s):

Regression Model ◽

Causal Relationship ◽

World Bank ◽

Least Square ◽

Doing Business ◽

Least Square Regression ◽

Foreign Countries ◽

Ease Of Doing Business ◽

The Impact ◽

Starting A Business

This study investigates the impact of Ease of Doing Business on Inward FDI over the period from 2011 to 2015 across the globe. This study measures ease of doing business using starting a business, getting credit, registering property, paying taxes and enforcing contracts. The research used a sample of 177 countries from 190 countries listed in World Bank. Least square regression model via E-views software used to examine causal relationship. The study found that ease of doing business indicators ‘Enforcing Contracts’ was found to have a positive significant impact on Inward FDI. Nevertheless, ‘Getting Credit’ and ‘Registering Property’ were found to have a negative significant impact on Inward FDI. However, ‘Starting a Business’ and ‘Paying Taxes’ have no significant impact on Inward FDI in the studied timeframe of this research. The findings of the study suggested the ease of doing business enables inward FDI through better contract enforcements, getting credit and registering property. The findings of the research will assist international managers and companies to know the importance of ease of doing business when investing in foreign countries through FDI.

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Income Diversification and Bank Efficiency in Vietnam

Journal of Economics and Development ◽

10.33301/jed.2017.19.03.04 ◽

2017 ◽

pp. 52-67

Author(s):

Sang Nguyen Minh

Keyword(s):

Regression Model ◽

Commercial Banks ◽

Banking System ◽

Operational Efficiency ◽

Commercial Banking ◽

Tobit Regression ◽

Income Diversification ◽

Positive Effects ◽

Study Results ◽

The Impact

This study uses the DEA (Data Envelopment Analysis) method to estimate the technical efficiency index of 34 Vietnamese commercial banks in the period 2007-2015, and then it analyzes the impact of income diversification on the operational efficiency of Vietnamese commercial banks through a censored regression model - the Tobit regression model. Research results indicate that income diversification has positive effects on the operational efficiency of Vietnamese commercial banks in the research period. Based on study results, in this research some recommendations forpolicy are given to enhance the operational efficiency of Vietnam’s commercial banking system.

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