The building level substation - the innovation of district heating system: Version II

The building level substation (BLS) is suggested here as an innovation to the District Heating (DH) sector development in China. Introduction of the BLS would provide obvious benefits in improved energy efficiency and living comfort, but it also faces institutional barriers to overcome. CHP concept will be described, and the economic, institutional and technical issues associated to BLS will be addressed. The BLS units are prefabricated compact products that are designed, manufactured and tested at the factory ready for transportation to the construction site, where the complete BLS unit will be mounted to the floor, connected to the existing indoor piping of heating and water, the remote communication facilities as well as to power supplies of the building. The BLS as an integrated plate heat exchange unit shall be prefabricated and assembled and successfully tested both hydraulically and electrically in the factory already to meet the high functional and low noise requirements, and if he so wishes, at the presence of the Borrower's representative. Its base and brazed structures should have sufficient intensity and stability. Domestic hot water (DHW) can also be integrated to DH. BLS makes it possible to complement the DH with DHW afterwards at low incremental costs: a small heat exchanger and a small circulation pump as well as connection to the existing DHW and city water piping are needed. BLS can be also equipped with an automatic remote red meter (ARM) to follow energy consumption. This BLS manual is updated from the 1st version done in Oct. 2015 (VTT Technology 231, available at: www.vtt.fi/inf/pdf/technology/2015/T231.pdf). Chapter 2 and 3 are added into the 2nd version. Also some parts of the text are reorganized in new order and some text is added and some taken off. The text called "Global trends" is added in Annex 2.