A stochastic bottom-up model for space heating and domestic hot water load profiles for German households

2016 ◽  
Vol 124 ◽  
pp. 120-128 ◽  
Author(s):  
David Fischer ◽  
Tobias Wolf ◽  
Johannes Scherer ◽  
Bernhard Wille-Haussmann
Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 476
Author(s):  
Vincenza Brancato ◽  
Larisa G. Gordeeva ◽  
Angela Caprì ◽  
Alexandra D. Grekova ◽  
Andrea Frazzica

In this study, the development and comparative characterization of different composite sorbents for thermal energy storage applications is reported. Two different applications were targeted, namely, low-temperature space heating (SH) and domestic hot water (DHW) provision. From a literature analysis, the most promising hygroscopic salts were selected for these conditions, being LiCl for SH and LiBr for DHW. Furthermore, two mesoporous silica gel matrixes and a macroporous vermiculite were acquired to prepare the composites. A complete characterization was performed by investigating the porous structure of the composites before and after impregnation, through N2 physisorption, as well as checking the phase composition of the composites at different temperatures through X-ray powder diffraction (XRD) analysis. Furthermore, sorption equilibrium curves were measured in water vapor atmosphere to evaluate the adsorption capacity of the samples and a detailed calorimetric analysis was carried out to evaluate the reaction evolution under real operating conditions as well as the sorption heat of each sample. The results demonstrated a slower reaction kinetic in the vermiculite-based composites, due to the larger size of salt grains embedded in the pores, while promising volumetric storage densities of 0.7 GJ/m3 and 0.4 GJ/m3 in silica gel-based composites were achieved for SH and DHW applications, respectively.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.


2019 ◽  
Vol 111 ◽  
pp. 04013
Author(s):  
Hye-Sun Jin ◽  
Han-Young Lim ◽  
You-Jeong Kim ◽  
Soo-Jin Lee ◽  
Sung-Im Kim ◽  
...  

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.


2014 ◽  
Vol 889-890 ◽  
pp. 1333-1336
Author(s):  
Yu Fu ◽  
Kai Chen ◽  
Fei Ying Fu ◽  
Xin Bin Wang

Solar thermal collector converts solar radiation energy into useful thermal energy and transfers to a transport fluid flowing through the system. The collected energy can be used either direct to space or water heating equipment, or to a thermal storage for later use. Along with fast development, not only domestic hot water supply is needed, but also space heating and cooling are required. Also, limited roof space is another key barrier that should be considered. Furthermore, most of the building integration with solar collectors are mounted on the roof top by flat or tilt angle at present. It is considered to be a failure of low level architectural quality because the collector is used only for application and seems as an independent technical element of the building. With the consideration of the above, novel type of solar collector has been proposed to realize the utilization and offset the barriers. This novel solar collectors is especially suitable to supply domestic hot water, and combines with ASHP for multi-function, space heating and cooling as well as domestic hot water supply. Additionally, it is well integrated with high-rise residential buildings, which is good for aesthetic.


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