Supply of district heating to areas with low heat demand
Recent years have witnessed a wide range of energy saving measures in Denmark, which have decreased the unit heat consumption by district heating consumers dramatically. The geometrical density of new district heating consumers has also decreased as a result of increased living standards - larger distance to neighbours.
The project will present recommendations for design of district heating distribution systems to supply buildings with low energy demand or in other areas with low heat density. The project will deal with the financial viable limits for district heating using known supply methods, and how to optimize these methods and what this will mean as regard to investments and capacity. In a number of scenarios, the consequences of the following initiatives will be analyzed: 1) Decreasing dimensions of district heating system by establishing booster pumps. Calculations to find optimal pipe dimensions and optimal locations and size of booster pumps will be made with regard to initial expenditure and operation and maintenance. Life span will be evaluated. 2) Examination of twin-pipes for district heating. 3) Separate examination of down-dimensioning of flow pipes. The end report will: 1) Form basis for decision for connection of areas with low energy demand. 2) Give recommendation to the connection form that is most energy economic
These factors are the main contributors to increased heat distribution costs, measured in both investments and heat losses, when new areas are supplied. However, a significant development of the technologies available for district heating enterprises is taking place. It mainly concerns improved control systems, new pump technologies, energy saving pipes and design tools. The decreasing density of heat consumption and the improved technologies influence the optimal design of heat distribution systems. An optimal design has been investigated in the present project. This involves the basic pipe system, the degree of insulation, media pipe dimensions, the numbers of pump stations and operational principles. In general, the correct pipe dimension in distributon networks is found by minimising the sum of four main cost components: pipe investments, pipe operation, pump investments and pump operation. there are many factors, which influence these four cost components, such as energy prices, the ratio of heat capacity demand and annual heat transmission, temperatures in the network, pipe network geometry and pressure limits. These factors are investigated in order to produce new guidelines to meet the challenge of future district heating schemes. Calculations on entire pipe networks indicate that co-insuated pipe systems result in savings of up to 25% of the total distribution costs of traditional pipe systems and up to 50% of the total pipe losses. Furthermore, reduced dimensions and high gradients with regard to small pipes lead to savings of up to 10% of the distribution costs of traditional design
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| STAR PIPE A/S | ||
| GRUNDFOS A/S | ||
| Nykøbing Falster Kommune | ||
| Danmarks Tekniske Universitet (DTU) |
Contact
Granskoven 8
DK-2600 Glostrup, Denmark
Bruus, Finn , 43484462, fbs@carlbro.dk
Øvr. Partnere: Danmarks Tekniske Universitet; Grundfos A/S; Nykøbing Falster Kommune
