Sensitivity of district heating system operation to heat demand reductions and electricity price variations: A Swedish example

Energy ◽  
2012 ◽  
Vol 41 (1) ◽  
pp. 525-540 ◽  
Author(s):  
M. Åberg ◽  
J. Widén ◽  
D. Henning
2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3673-3684
Author(s):  
Borna Doracic ◽  
Marino Grozdek ◽  
Tomislav Puksec ◽  
Neven Duic

District heating systems already play an important role in increasing the sustainability of the heating sector and decreasing its environmental impact. However, a high share of these systems is old and inefficient and therefore needs to change towards the 4th generation district heating, which will incorporate various energy sources, including renewables and excess heat of different origins. Especially excess heat from industrial and service sector facilities is an interesting source since its potential has already been proven to be highly significant, with some researches showing that it could cover the heat demand of the entire residential and service sector in Europe. However, most analyses of its utilisation in district heating are not done on the hourly level, therefore not taking into account the variability of its availability. For that reason, the main goal of this work was to analyse the integration of industrial excess heat into the district heating system consisting of different configurations, including the zero fuel cost technologies like solar thermal. Furthermore, cogeneration units were a part of every simulated configuration, providing the link to the power sector. Excess heat was shown to decrease the operation of peak load boiler and cogeneration, that way decreasing the costs and environmental effect of the system. However, since its hourly availability differs from the heat demand, thermal storage needs to be implemented in order to increase the utilisation of this source. The analysis was performed on the hourly level in the energyPRO software


2021 ◽  
Vol 246 ◽  
pp. 09003
Author(s):  
Haoran Li ◽  
Juan Hou ◽  
Yuemin Ding ◽  
Natasa Nord

Peak load has significant impacts on the economic and environmental performance of district heating systems. Future sustainable district heating systems will integrate thermal storages and renewables to shave their peak heat demand from traditional heat sources. This article analysed the techno-economic potential of implementing thermal storage for peak load shaving, especially for the district heating systems with waste heat recovery. A campus district heating system in Norway was chosen as the case study. The system takes advantage of the waste heat from the campus data centre. Currently, about 20% of the heating bill is paid for the peak load, and a mismatch between the available waste heat and heat demand was detected. The results showed that introducing water tank thermal storage brought significant effects on peak load shaving and waste heat recovery. Those effects saved up to 112 000 EUR heating bills annually, and the heating bill paid for the peak load could be reduced by 15%. Meanwhile, with the optimal sizing and operation, the payback period of the water tank could be decreased to 13 years. Findings from this study might help the heat users to evaluate the economic feasibility of introducing thermal storage.


Author(s):  
Daniela Popescu ◽  
Elena Serban ◽  
Carmen-Ema Panaite ◽  
Abel Herna´ndez-Guerrero

The aim of this work is to study the influence of pressure loss parameters from a district heating system on the distribution of fluid flow rates. The research was finalized by improving the mathematical model of a district heating network, which comprises an algebraic non-linear system that synthesizes flow balance equations of a stationary flow. This enhanced model indicates the influence of every consumer’s heat demand supplied from a district heating network on the fluid flow rates distribution based on the means of the implicit function theorem. The originality of the method consists of considering the network a sensitive system that responds to the variations of input parameters (pressure loss parameters) by variations of output parameter (fluid flow rates). The main advantage is that the engineer in charge with exploitation of the heating system may understand what happens with the flow allocations when pressure loss parameters of the network are different from the nominal ones, without making any measurements on the field or computations using new scenarios. The method presented in this paper facilitates the choice of the best decision concerning balancing and practical management of radial heating networks.


2000 ◽  
Vol 6 (5) ◽  
pp. 366-370
Author(s):  
Jūratė Karbauskaitė ◽  
Vytautas Stankevičius

In this paper the results of statistic analysis of heat consumption in apartment heating systems for Lithuania are discussed. Kaunas district heating system data are used for the analysis. Total sum of buildings involved is about 1900, including 1550 with the average heated area of 4000 m2. It has been established that real heat consumption in apartment buildings is less than the design heat demand (Fig 1), especially in small buildings (Fig 2). The distribution of monthly differences is presented in Fig 3. The difference during months does not depend on average outdoor temperature, but it could be caused by temperature fluctuations and solar radiation. It is quite important to determine the reasons of different heat consumption in buildings. For this purpose 20 dwelling houses of various design and building period, with various energy consumption problems have been selected for more detailed energy audit. Volumes of external building elements, changes in destination of premises, heated area have been estimated as well as the state of heat supply sub-station equipment. According to the data obtained, the energy consumption was determined for standard month at mean indoor and outdoor climate values. The results are compared with real energy consumption in the selected buildings and design values. It has been established that the inadequacies in exceeded energy consumption over design values are mostly caused by incorrect heated area registration and premises destination change, in a less range by absence of maintenance, eg broken outside doors, damaged roofs etc. Energy consumption in dwelling houses with design indoor temperature and normal maintenance level usually is near to the design value or less up to 10%. In dwelling houses, in which energy consumption is defined as being of less design value, some energy saving measures are applied, eg temperature in spaces is lowered up to 16°C, about half of balconies are glassed, electric stoves for cooking are installed as additional heat source. Such apartment buildings, as a rule, do not have premises of other destination. By such means near 40% of heat is saved.


2020 ◽  
Vol 10 (1) ◽  
pp. 18-22
Author(s):  
Cristina CALIN ◽  
Eugen Victor RUSU ◽  
Ion ION ◽  
Gabriel MOCANU

The energy, economic and environmental analysis of a solar heating system with seasonal heat storage integrated into a district heating system based on natural gas boiler was performed. The solar collector field has a surface area of 8720 m2 and the pit seasonal heat storage has a volume of 10000 m3. This system covers 79% of the total yearly heat demand of the 15 multifamily buildings with 1500 inhabitants. The total system investment cost (2974100 €) may be recovered in about 17 years. The environmental impact of solar heating system integration is the decrease of CO2 emission by 79%.


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