A Theoretical Study on Decentralized Space Heating System

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Zhi-Ping Song
Keyword(s):  
Energy Conservation ◽  
Total Energy ◽  
Global Climate ◽  
Energy System ◽  
Specific Consumption ◽  
Space Heating ◽  
Full Potential ◽  
Heating Systems ◽  
End Use ◽  
The Impact

Global climate change mitigation requires the fossil fuel consumption substantially reduced. Space heating is an energy-consuming sector. Despite the fact that the thermal efficiency of current space heating systems has achieved a value higher than 85%, corresponding to lower than 40kg c.e./GJ, there is still a big potential for energy conservation. In order to realize the full potential, investigations of heating systems should appeal to reversibility/exergy analysis made on total energy concept basis. This paper starts with an introduction of the concept “reversible mode of heating,” leading the readers think of space heating in terms of reversibility. Right after, a systematic reversibility analysis on a “mine to home” basis is conducted to reveal the impact of any irreversibility of all subsystems or devices involved in the total energy system of heating on the fuel/monetary specific consumption of unit end-use heat. The paper points out that although combined heat and power (CHP) and electrically driven heat pump are both of “reversible mode,” the former is far more favorable in terms of energy conservation. The recently ascent decentralized energy system provides the best circumstances for CHP implementation. The demand-side improvement is a topic of most importance but frequently neglected. This study reveals that, if properly engineered, this improvement together with adopting a direct type of heat grid might lower the fuel specific consumption of end-use heat of CHP to a level as low as 13–9kg c.e./GJ.

scholarly journals Efficiency of Space Heating Systems under the Climate Change

2019 ◽  
Vol 103 ◽  
pp. 02002
Author(s):  
Vladimir Klimenko ◽  
Sergey Krasheninnikov ◽  
Ekaterina Fedotova
Keyword(s):  
Climate Change ◽  
Power Plant ◽  
Global Climate ◽  
Climate Scenario ◽  
Careful Consideration ◽  
Space Heating ◽  
Statistical Parameters ◽  
Climate Conditions ◽  
Heating Systems ◽  
The Impact

Impacts of the climate change on the space heating systems are discussed. We have used the latest global temperature data of the Global Climate Historical Network to demonstrate that the heating and cooling demand combined is decreasing in the world regions with boreal and moderate climate conditions almost everywhere. A simulation approach was developed to assess the impact of the climate change of the efficiency of a modern binary-cycle cogeneration power plant. Both statistical parameters of the air temperature and the thermal circuit of the power plant were modeled in details. It was found that even for a quite optimistic climate scenario the annual efficiency decrease may be as high as 1-2%. This means that careful consideration of the climate-related heating load dynamics is of key importance by implementation and renovation of the district heating systems.

scholarly journals Analysis of Annual Energy Use Intensities (EUIs) by End-Use in Apartment Units According to Stratification Variables (2017 – 2018)

2019 ◽  
Vol 111 ◽  
pp. 04013
Author(s):  
Hye-Sun Jin ◽  
Han-Young Lim ◽  
You-Jeong Kim ◽  
Soo-Jin Lee ◽  
Sung-Im Kim ◽  
...  
Keyword(s):  
Information System ◽  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Use ◽  
Hot Water ◽  
Space Heating ◽  
Building Sector ◽  
Domestic Hot Water ◽  
Space Cooling ◽  
End Use

To achieve the goal of reducing greenhouses gases, many countries have recognized the importance of energy conservation in the building sector, and such countries are considerably strengthening their building energy conservation policies by reinforcing design standards, encouraging remodeling, and requiring zero-energy construction. In order to effectively strengthen these policies, it is necessary to provide information concerning energy consumption in the building sector to ensure the technical and economic feasibility of policies in the marketplace, and to allow building users and policy makers to easily access and understand energy consumption characteristics. It is important to provide information that allows people to effectively understand the state of energy consumption by end-use (space heating, space cooling, domestic hot water, etc.) as part of the creation of a concrete plan for energy reduction that incorporates various service systems and is familiar to people. This is because providing such information plays an important role in establishing concrete policies and encouraging voluntary energy performance improvements by building occupants. South Korea operates the Korea Energy Statistics Information System (KESIS) and the information provided by this type of information system consists mainly of energy consumption by energy source (electricity, gas, etc.), and such systems remain inadequate for providing effective information on energy consumption and energy use intensity (EUI) by end-use (space heating, space cooling, domestic hot water, etc.) as part of the creation of a concrete plan for energy conservation. In order to accurately provide energy consumption information by end-use rather than limit the information to mainly consumption corresponding to energy sources, in this study, measurement systems were installed in 2014 ~ 2016 based on the overall sampling designs of previous studies for apartment units, classifications, measurement and data gathering methods for energy consumption by end-use. The annual statistical values for EUI by end-use were collected from the measurement data for 71 sample apartment units from May 2017 to April 2018. This data was calculated and analyzed using stratification variable levels for completion year, supplied area, and the heat source type.

Impact of roof shading on building energy performance in warm & humid climatic places of India

2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
General Assumption ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Passive Cooling ◽  
Base Case ◽  
U Value ◽  
The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

Impact of LULC Changes on LST in Rajshahi District of Bangladesh: A Remote Sensing Approach

2020 ◽  
Vol 3 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Abdulla Al Kafy ◽  
Abdullah Al-Faisal ◽  
Mohammad Mahmudul Hasan ◽  
Md. Soumik Sikdar ◽  
Mohammad Hasib Hasan Khan ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Temperature ◽  
Land Surface ◽  
Agricultural Land ◽  
Global Climate ◽  
Urban Expansion ◽  
Water Bodies ◽  
Landsat 8 ◽  
Lulc Changes ◽  
The Impact

Urbanization has been contributing more in global climate warming, with more than 50% of the population living in cities. Rapid population growth and change in land use / land cover (LULC) are closely linked. The transformation of LULC due to rapid urban expansion significantly affects the functions of biodiversity and ecosystems, as well as local and regional climates. Improper planning and uncontrolled management of LULC changes profoundly contribute to the rise of urban land surface temperature (LST). This study evaluates the impact of LULC changes on LST for 1997, 2007 and 2017 in the Rajshahi district (Bangladesh) using multi-temporal and multi-spectral Landsat 8 OLI and Landsat 5 TM satellite data sets. The analysis of LULC changes exposed a remarkable increase in the built-up areas and a significant decrease in the vegetation and agricultural land. The built-up area was increased almost double in last 20 years in the study area. The distribution of changes in LST shows that built-up areas recorded the highest temperature followed by bare land, vegetation and agricultural land and water bodies. The LULC-LST profiles also revealed the highest temperature in built-up areas and the lowest temperature in water bodies. In the last 20 years, LST was increased about 13ºC. The study demonstrates decrease in vegetation cover and increase in non-evaporating surfaces with significantly increases the surface temperature in the study area. Remote-sensing techniques were found one of the suitable techniques for rapid analysis of urban expansions and to identify the impact of urbanization on LST.

Clinical Pharmacokinetic Studies in Pregnant Women and the Relevance of Pharmacometric Tools

2019 ◽  
Vol 25 (5) ◽  
pp. 483-495 ◽  
Author(s):  
André Dallmann ◽  
Paola Mian ◽  
Johannes Van den Anker ◽  
Karel Allegaert
Keyword(s):  
Pregnant Women ◽  
Clinical Pharmacokinetic ◽  
Individual Variability ◽  
Current Status ◽  
Pharmacokinetic Studies ◽  
Full Potential ◽  
Pbpk Models ◽  
Pregnancy And Postpartum ◽  
Population Pk ◽  
The Impact

Background: In clinical pharmacokinetic (PK) studies, pregnant women are significantly underrepresented because of ethical and legal reasons which lead to a paucity of information on potential PK changes in this population. As a consequence, pharmacometric tools became instrumental to explore and quantify the impact of PK changes during pregnancy. Methods: We explore and discuss the typical characteristics of population PK and physiologically based pharmacokinetic (PBPK) models with a specific focus on pregnancy and postpartum. Results: Population PK models enable the analysis of dense, sparse or unbalanced data to explore covariates in order to (partly) explain inter-individual variability (including pregnancy) and to individualize dosing. For population PK models, we subsequently used an illustrative approach with ketorolac data to highlight the relevance of enantiomer specific modeling for racemic drugs during pregnancy, while data on antibiotic prophylaxis (cefazolin) during surgery illustrate the specific characteristics of the fetal compartments in the presence of timeconcentration profiles. For PBPK models, an overview on the current status of reports and papers during pregnancy is followed by a PBPK cefuroxime model to illustrate the added benefit of PBPK in evaluating dosing regimens in pregnant women. Conclusions: Pharmacometric tools became very instrumental to improve perinatal pharmacology. However, to reach their full potential, multidisciplinary collaboration and structured efforts are needed to generate more information from already available datasets, to share data and models, and to stimulate cross talk between clinicians and pharmacometricians to generate specific observations (pathophysiology during pregnancy, breastfeeding) needed to further develop the field.

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