district heat network performance review

Client

Manchester Metropolitan University

The Brief

The Birley Field campus consists of accommodation blocks for 1000 students and an academic block. The site is served by a LTHW district heating system generated from an energy centre with 3000 kW of gas fired boiler plant with an additional 400kW generated by the rejected heat from a Combined Heat and Power unit with thermal storage.

d3associates were commissioned to conduct a conditional survey of the Energy Centre and the satellite plant rooms located in accommodation blocks as well as the Academic block, with two main roof top plant rooms. The purpose of this survey was to review the control and hydraulic arrangements of the existing heat interface units and district heating network with the intent to provide hydraulic model (developed with Hydraulic Analysis Limited) and recommendations with regard to optimising the LTHW systems flow rate with supply and return temperatures whilst optimising the usage of the CHP plant and thermal storage and effectively utilising the rejected heat into the district heating system.

The Outcome

d3associates confirmed the suitability of the existing district heating primary pumps to meet the varying loads throughout the year. Further analysis of the heating demand profiles for space heating, mechanical ventilation and domestic hot water usage attributed to the accommodation blocks and academic building was undertaken. New heat metering devices were installed to provide data to for input into the hydraulic model soft ware. Once this data input is completed during the heating season the model will be used to fine tune the controls and operation for the most economic operation of the CHP, thermal storage and gas fired boilers.The whole process has relied upon a relationship being developed between the surveying team and the University Estates Department. Work to verify the impact of the improvements to the control systems is ongoing.