Urumqi district heating - review of pipeline design

Urumqi District Heating China 
 Photo: COWI/Andrew T. Christensen.
During the past years, Urumqi District Heating Company in Xinjiang Province has been working intensively with replacing of heat supply from many small and polluting coal-fired boilers with surplus heat from new power plants.

This initiative has had a significant environmental impact. However, it has also resulted in a much more complex district heating system with increasing requirements for system design and control strategies as a consequence.

Since 1998, COWI has been involved in two projects for Urumqi District Heating Company. Both projects have included evaluation of the proposed design of new transmission and distribution pipelines. The areas concerned were:

  • The district of Wei Hu Liang with a heat capacity of approximately 300 MW, supplying around 5 million m2;
  • South Urumqi district with a heat capacity of 750 MW, supplying around 12,5 million m2.

In both cases, the assessment of safety and operational aspects of new district heating transmission and distribution pipes has been the main objective of the work. One of the essential aspects has been to examine how the large elevation differences of the areas could be taken properly into account when designing and operating the system.

COWI has carried out the work on the basis of hydraulic steady-state and transient analyses of the proposed district heating systems, focusing on issues such as risk of water hammering, cavitation and emergency situations. Calculations and analysis results have been used to review design concepts and different design alternatives.

Subsequently, proposals for improvements in the conceptual design of pipelines and control strategies have been presented to the district heating company. Most of the recommendations have been adopted and are part of the reason why Urumqi District Heating Company has experienced a successful integration of surplus heat from new power plants in its district heating system.

LAST UPDATED: 18.09.2017