https://vbn.aau.dk/ws/files/301711589/The_Status_of_4_Generation_District_Heating_Research_and_Results.pdf

The status of 4th generation district heating: Research and results

https://research.aalto.fi/files/17305461/1_s2.0_S0360544217314548_main.pdf

Utilizing data center waste heat in district heating – Impacts on energy efficiency and prospects for low-temperature district heating networks

https://orbit.dtu.dk/files/133956922/1_s2.0_S1876610217322592_main.pdf

Low Temperature District Heating for Future Energy Systems

Bottom-up modelling methodology for urban-scale analysis of residential space heating demand response

System dynamics model analysis of pathway to 4th generation district heating in Latvia

Background and ObjectiveThe evolution of district heating (DH) has gone through three generations since the first introduction of distirct heating. It is characterized by the type of transport media and the network temperature levels: the 1st generation DH system is steam-based system, the 2nd generation DH uses high network supply temperature above 100oC, and the 3rd generation DH represents the current DH system with medium network supply temperature between 80oC to 100oC. Up until now, the 4th generation DH as the low-temperature district heating (LTDH) is emerging as a new system which is going to replace the existing 3rd generation DH system. Comparing with the existing DH system, the LTDH reduces the network supply temperature down to consumer required temperature level, thus greatly improves the quality match between the energy supply and the energy demand. Meanwhile, LTDH coupling with reduced network temperature and well-designed DH network can reduce network heat loss by up to 75% comparing with the current system. This makes DH economically competitive comparing with local heat generation units in the areas with low heat density or with low-energy buildings.The traditional approach to evaluating a DH system often focuses on the production/supply aspect and only afterwards on the final users. The LTDH concept switches the perspective, starting from end-user thermal comfort and a quality match between energy supply and energy consumption, and aiming to find the best and most economical way to satisfy the heat demand through efficient distribution networks and supply systems based on waste heat and RE. The new concept therefore starts by identifying suitable in-house substations for low-energy-demand buildings at low supply temperature, goes back to design efficient and reliable networks, and finally considers environmentally-friendly heat production units.This report describes the concept of LTDH, collects and discusses successful examples of implementation LTDH in the building heating sector. The objective of this report is to raise awareness and provide insights that will stimulate the research, development and implementation of LTDH systems. It will help to increase public recognition and assist policy makers and energy planners, both at local and governmental level, in promoting cost-effective and environmentally friendly DH systems, and in planning and realizing long-term sustainable urban area development. To this end, the report addresses the following research issues:1. What are the main advantages of LTDH?2. What technology options are available for LTDH, and what are the associated challenges to consider?3. How can the risk of Legionella be mitigated in LTDH?4. What lessons can be learned from early LTDH projects?5. What heat distribution costs are associated with LTDH?

Toward 4th generation district heating: experience and potential of low-temperature district heating

IEA DHC Annex X report:Toward 4th Generation District Heating: Experience and Potential of Low-Temperature District Heating

To achieve CO2 emissions reductions, the UK Building Regulations require developers of new residential buildings to calculate expected CO2 emissions arising from their energy consumption using a methodology such as Standard Assessment Procedure (SAP 2005) or, more recently SAP 2009. SAP encompasses all domestic heat consumption and a limited proportion of the electricity consumption. However, these calculations are rarely verified with real energy consumption and related CO2 emissions. This work presents the results of an analysis based on weekly heat demand data for more than 200 individual flats. The data were collected from a recently built residential development connected to a district heating network. A method for separating out the domestic hot water (DHW) use and space heating (SH) demand has been developed and these values are compared to the demand calculated using SAP 2005 and SAP 2009 methodologies. The analysis also shows the variation in DHW and SH consumption with size of flats and with tenure (privately owned or social housing). Evaluation of the space heating consumption also includes an estimate of the heating degree day (HDD) base temperature for each block of flats and compares this to the average base temperature calculated using the SAP 2005 methodology.

Martin Crane

Papers

Toward 4th generation district heating: experience and potential of low-temperature district heating

IEA DHC Annex X report:Toward 4th Generation District Heating: Experience and Potential of Low-Temperature District Heating

Space heating and hot water demand analysis of dwellings connected to district heating scheme in UK

Annex X Final report : Toward 4th Generation District Heating: Experience and Potential of Low-Temperature District Heating