Bringing Combined Heat and Power/District Heating to Two UK Cities

Author(s):  
P C Warner ◽  
R A McFadden ◽  
R A J Moodie ◽  
G P White

Edinburgh and Belfast are two of the cities where the financial prospects for district heating from combined heat and power (CHP) are being investigated by consortia combining industrial membership (substantially the same for both) with strong local interests; the object is to learn whether city CHP schemes can appeal to the private investor. The paper deals with the historical build-up of interest in CHP in both places, leading to the formation of consortia in response to a government invitation, and the award of grant-in-aid announced in January 1985. It then explains how the two studies have been planned and sets out their content: the key technical and commercial factors, and also the statutory and other more general considerations. The work is well under way, and the paper reports on progress, including field work to ascertain heat demand, the choice of fuels and sites for heat-only sources and for the combined plant, and the sequencing of implementation progressively across the city.

2014 ◽  
Vol 472 ◽  
pp. 1052-1056
Author(s):  
Chun Hui Liao ◽  
Zhi Gang Zhou ◽  
Jia Ning Zhao

For evaluating the performance of combined heat and power district heating (CHP-DH) system, some thermodynamic indicators of CHP system, include energy efficiency, exergy efficiency, RPES and RAI, are introduced in this paper. Based on two condensed and heating dual purpose plants, the values of these indicators are calculated with different extraction ratio. The results show that RAI and RPES are more reasonable to be used to assess CHP-DH system and there is a minimum extraction ratio for each unit, which is 0.4 for given plants in this paper, to keep CHP-DH beneficial compared with separate heat and power (SHP) system. Besides, the minimum heat demand of CHP-DH system should be larger than the supplied heat correspond to minimum extraction ratio.


2019 ◽  
Vol 9 (10) ◽  
pp. 1994
Author(s):  
Petri Hietaharju ◽  
Mika Ruusunen ◽  
Kauko Leiviskä ◽  
Marko Paavola

Easily adaptable indoor temperature and heat demand models were applied in the predictive optimization of the heat demand at the city level to improve energy efficiency in heating. Real measured district heating data from 201 large buildings, including apartment buildings, schools and commercial, public, and office buildings, was utilized. Indoor temperature and heat demand of all 201 individual buildings were modelled and the models were applied in the optimization utilizing two different optimization strategies. Results demonstrate that the applied modelling approach enables the utilization of buildings as short-term heat storages in the optimization of the heat demand leading to significant improvements in energy efficiency both at the city level and in individual buildings.


Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2874 ◽  
Author(s):  
Dmytro Romanchenko ◽  
Emil Nyholm ◽  
Mikael Odenberger ◽  
Filip Johnsson

Using an integrated demand-supply optimization model, this work investigates the potential for flexible space heating demand, i.e., demand response (DR), in buildings, as well as its effects on the heating demand and the operation of a district heating (DH) system. The work applies a building stock description, including both residential and non-residential buildings, and employs a representation of the current DH system of the city of Gothenburg, Sweden as a case study. The results indicate that space heating DR in buildings can have a significant impact on the cost-optimal heat supply of the city by smoothing variations in the system heat demand. DR implemented via indoor temperature deviations of as little as +1 °C can smoothen the short-term (daily) fluctuations in the system heating demand by up to 18% over a period of 1 year. The smoothening of the demand reduces the cost of heat generation, in that the heat supply and number of full-load hours of base-load heat generation units increase, while the number of starts for the peaking units decreases by more than 80%. DR through temperature deviations of +3 °C confers diminishing returns in terms of its effects on the heat demand, as compared to the DR via +1 °C.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2347
Author(s):  
Elżbieta Hałaj ◽  
Jarosław Kotyza ◽  
Marek Hajto ◽  
Grzegorz Pełka ◽  
Wojciech Luboń ◽  
...  

Krakow has an extensive district heating network, which is approximately 900 km long. It is the second largest city in terms of the number of inhabitants in Poland, resulting in a high demand for energy—for both heating and cooling. The district heating of the city is based on coal. The paper presents the conception of using the available renewable sources to integrate them into the city’s heating system, increasing the flexibility of the system and its decentralization. An innovative solution of the use of hybrid, modular heat pumps with power dependent on the needs of customers in a given location and combining them with geothermal waters and photovoltaics is presented. The potential of deep geothermal waters is based on two reservoirs built of carbonate rocks, namely Devonian and Upper Jurassic, which mainly consist of dolomite and limestone. The theoretical potential of water intake equal to the nominal heating capacity of a geothermal installation is estimated at 3.3 and 2.0 MW, respectively. Shallow geothermal energy potential varies within the city, reflecting the complex geological structure of the city. Apart from typical borehole heat exchangers (BHEs), the shallower water levels may represent a significant potential source for both heating and cooling by means of water heat pumps. For the heating network, it has been proposed to use modular heat pumps with hybrid sources, which will allow for the flexible development of the network in places previously unavailable or unprofitable. In the case of balancing production and demand, a photovoltaic installation can be an effective and sufficient source of electricity that will cover the annual electricity demand generated by the heat pump installation, when it is used for both heating and cooling. The alternating demand of facilities for heating and cooling energy, caused by changes in the seasons, suggests potential for using seasonal cold and heat storage.


2016 ◽  
Vol 5 (12) ◽  
pp. 219 ◽  
Author(s):  
Tobias Törnros ◽  
Bernd Resch ◽  
Matthias Rupp ◽  
Hartmut Gündra

Author(s):  
Christof Weinlaender ◽  
Johannes Albert ◽  
Christian Gaber ◽  
Martin Hauth ◽  
René Rieberer ◽  
...  

This paper presents the development of the subsystems for stationary biogas powered solid oxide fuel cell (SOFC)-based combined cooling, heat and power (CCHP). For certain applications, such as buildings, a heat-driven operation mode leads to low operating hours per year for conventional combined heat and power (CHP) systems due to the low heat demand during the summer season. The objectives of this study are the evaluation of an adsorber, a steam reformer, a SOFC, and an absorption chiller (AC). Biogas, however, contains impurities in the form of hydrogen sulfide (H2S), hydrogen chloride (HCl), and siloxanes in different concentrations, which have a negative effect on the performance and durability of the SOFC and, in the case of H2S, also on the catalyst of the steam reformer. This paper describes different experimental sections: (i) the biogas treatment with its main focus on H2S separation and steam reforming, (ii) the setup and start-up of a 10 cell SOFC stack, and (iii) test runs with an AC using a mixture of NH3 (ammonia)/H2O (water). The components required for the engineering process of the subsystem's structure are described in detail and possible options for system design are explained. The evaluation is the basis to reveal the improvement potentials, which have to be considered in future product developments. This paper aims at comparing experimental data of the test rigs to develop an understanding of the requirements for a stable and continuous operation of a SOFC-based CCHP operated by biogas.


1994 ◽  
Vol 36 (1) ◽  
pp. 3-35 ◽  
Author(s):  
Deborah Winslow

In February 1989, in Pune, a city of a million people in the western Indian state of Maharashtra, I visited a simple outdoor pottery workshop. It consisted of a shallow pit kiln surrounded by eleven spaces shaded by gunny sacks on a flat area at the top of stairs leading down to a large river that ran through the city center. The families who used this space werekumbhars, members of a Hindu caste group found throughout the subcontinent. In India to teach, I thought that time spent with these potters might provide a perspective on Sinhalese potters I had known in a Sri Lankan village in the 1970s.The Indian potters were willing, so this first visit was followed by many more over the next four months.


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