scholarly journals The future of DH and the role of solar thermal energy

2020 ◽  
Author(s):  
Ralf-Roman Schmidt ◽  
Paolo Leoni ◽  
Hamid Aghaie
Keyword(s):  
District Heating ◽  
Global Scale ◽  
Solar Thermal ◽  
Heat Sources ◽  
Solar Thermal Energy ◽  
Heating And Cooling ◽  
Operation Costs ◽  
Almost Everywhere ◽  
Systemic Level

Solar thermal (ST) energy is one of the few renewable heat sources that is available almost everywhere and can bring multiple benefits to district heating and cooling (DHC) networks (on an environmental and systemic level) with very low operation costs and risks. However, the current share of ST in DHC networks is almost zero on a global scale.

scholarly journals SWOT analysis of ST integration in DHC systems

2020 ◽  
Author(s):  
Paolo Leoni ◽  
Ralf-Roman Schmidt ◽  
Roman Geyer ◽  
Patrick Reiter
Keyword(s):  
Swot Analysis ◽  
District Heating ◽  
Global Scale ◽  
Solar Thermal ◽  
Heat Sources ◽  
Heating And Cooling ◽  
Operation Costs ◽  
Almost Everywhere ◽  
Systemic Level

Solar thermal (ST) energy is one of the few renewable heat sources that is available almost everywhere and can bring multiple benefits to district heating and cooling (DHC) networks (on an environmental and systemic level) with very low operation costs and risks. However, the current share of ST in DHC networks is almost zero on a global scale.

scholarly journals Sensitivity of Tropical Cyclone Intensification to Axisymmetric Heat Sources: The Role of Low-Level Heating and Cooling from Different Microphysical Processes

2018 ◽  
Vol 75 (12) ◽  
pp. 4229-4246
Author(s):  
Georgina Paull ◽  
Konstantinos Menelaou ◽  
M. K. Yau
Keyword(s):  
Tropical Cyclone ◽  
Hurricane Katrina ◽  
Heat Sources ◽  
Absolute Vorticity ◽  
Heating And Cooling ◽  
Tangential Wind ◽  
Case Simulation ◽  
Microphysical Processes ◽  
Background State

Abstract Latent heat release from condensational heating has been recognized as one of the dominating energy sources of a tropical cyclone. Here we argue that other microphysical processes may also play an important role. From an analysis of a real-case simulation of Hurricane Katrina (2005), it was found that cooling from evaporation and melting of some frozen hydrometeors radially outside the eyewall region can have similar magnitudes as condensational heating. Based on this finding, idealized thermally forced experiments were performed. The specified heating and cooling functions mimic those found in the Hurricane Katrina run. The results indicated that the addition of cooling enhances the lower-level inward radial winds, which in turn increases the acceleration of the lower-level tangential winds through an enhanced transport of absolute vorticity. Sensitivity experiments on varying the structure of the cooling functions and the background state of the vortex demonstrate that the lower-level tangential wind acceleration is more sensitive to changes in the vertical structure and location of the cooling than the radial characteristics. In addition, the lower-level acceleration is sensitive to variations in the inertial and static stabilities rather than the vertical tangential wind shear of the initial vortex and its environment.

scholarly journals Investigation on Relative Heat Losses and Gains of Heating and Cooling Networks

2021 ◽  
Vol 25 (1) ◽  
pp. 479-490
Author(s):  
Violeta Madan ◽  
Ingo Weidlich
Keyword(s):  
District Heating ◽  
Energy System ◽  
Heat Losses ◽  
Heat Sources ◽  
Temperature Level ◽  
Near Surface ◽  
Heating And Cooling ◽  
Surface Soil Temperature ◽  
Steady State Heat ◽  
Sustainable Energy System

Abstract The integration of district heating (DH) and cooling (DC) in the sustainable energy system of the future requires a significant reduction in operating temperatures. Supply temperatures below 70 °C are required for new 4th Generation DH. Main benefits are the use of low exergy heat sources and the reduction of heat losses. The reduction of heat losses is achieved by reducing the driving temperature difference between the medium pipe and the ground. The decrease of the return temperature level is limited by the consumer behaviour and the ground temperature level. As a consequence, the reduction of the supply temperature is accompanied by a reduction of the maximum transmittable heat flow. For energy efficiency and economic reasons, the relative heat losses are therefore an important design value for DH networks. The study proposes an approach to estimate the relative heat losses by using steady-state heat loss models and analyses the values for different DH generations. In particular, due to the rising of the near-surface soil temperature, the relative cold losses are also studied.

The role of nanostructure morphology of nickel-infused alumina on solar-thermal energy conversion

2020 ◽  
Vol 23 (1) ◽  
pp. 015101
Author(s):  
Xuanjie Wang ◽  
Mei-Li Hsieh ◽  
James A Bur ◽  
Shawn-Yu Lin ◽  
Shankar Narayanan
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Thermal Energy Conversion

scholarly journals A methodology to integrate solar thermal energy in district heating networks confronted with a Swedish real case study

2017 ◽  
Vol 122 ◽  
pp. 865-870 ◽  
Author(s):  
Martin Joly ◽  
Gabriel Ruiz ◽  
Franz Mauthner ◽  
Paul Bourdoukan ◽  
Morgane Emery ◽  
...  
Keyword(s):  
Thermal Energy ◽  
District Heating ◽  
Solar Thermal ◽  
Real Case ◽  
Solar Thermal Energy ◽  
Heating Networks

A System Modeling Approach for Active Solar Heating and Cooling System With Phase Change Material (PCM) for Small Buildings

2012 ◽  
Author(s):  
Rajeevan Ratnanandan ◽  
Jorge E. González
Keyword(s):  
Phase Change ◽  
Thermal Energy ◽  
Cooling System ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Adsorption Chiller ◽  
Heating And Cooling ◽  
Solar Thermal Collectors ◽  
Change Material

The paper presents a study of the performance of an active solar thermal heating and cooling system for small buildings. The work is motivated by the need for finding sustainable alternatives for building applications that are climate adaptable. The energy demand for heating and cooling needs in residential and light commercial buildings in mid-latitudes represent more than 50% of the energy consumed annually by these buildings. Solar thermal energy represents an untapped opportunity to address this challenge with sustainable solutions. Direct heating could be a source for space heating and hot water, and for heat operated cooling systems to provide space cooling. However, a key limitation in mainstreaming solar thermal for heating and cooling has been the size of thermal storage to implement related technologies. We address this issue by coupling a Phase Change Material (PCM) with an adsorption chiller and a radiant flooring system for year round solar thermal energy utilization in Northern climates. The adsorption chiller allows for chill water production driven by low temperature solar thermal energy for summer cooling, and low temperature radiant heating provides for space heating in winter conditions, while hot water demand is supplied year round. These active systems are operated by high performance solar thermal collectors. The PCM has been selected to match temperatures requirements of the adsorption chiller, and the tank was designed to provide three levels of temperatures for all applications; cooling, heating, and hot water. The material selection is paraffin sandwiched with a graphite matrix to increase the conductivity. The specific objective of the preset work is to provide a system optimization of this active system. The system is represented by a series of mathematical models for each component; PCM tank with heat exchangers, the adsorption machine, the radiant floor, and the solar thermal collectors (Evacuated tubular collectors). The PCM modeling allows for sensible heating, phase change process, and superheating. Parametric simulations are conducted for a defined small building in different locations in US with the objective of defining design parameters for; optimal solar collector array, sizing of the PCM tank, and performance of the adsorption machine and radiant heating system. The monthly and annual solar fractions of the system are also reported.

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