District Energy - 2009 2nd Quarter

Capacity

Flow

Number of Buildings Connected

Length of Piping Network

Systems at a Glance

University of New Mexico Copenhagen Energy

Chilled-Water Steam HotWater Steam Network Network Network Network 11,200 tons 192 million 1,000 MW 1,714 million ( 40 MW) Btu/hr ( 56 MW) Btu/hr (500 MW)

15,000 gpm 160,000 lb/hr 2 million lb/hr ( 3,400 cu m/hr) ( 56 cu m/hr) (700 cu m/hr)

95 100 1,200

230,000 gpm ( 53,475 cu m/hr)

30,000

11 miles

900 miles

Supply Pressure

Supply Temperature

Source: 7- Technologies. information requires little interpretation when presented in a high-resolution graphical form, and comprehensive reporting tools are keys to providing decision-ready information.

60 psig ( 4 bar)

40 F ( 4 C)

120 and 40 psig ( 3 and 8 bar)

350 F
(175 C)

60 psig ( 4 bar)

176 F (80C)

180 miles main pipe and condensate return

172 psig ( 12 bar)

525 F/340 F (274 C/171 C)

but we now have reliable data to share in our optimization work with the staff from the building operations.” Additionally, RTTMS allows UNM to monitor and optimize the supply pressure temperature to make sure it is sufficient to meet a building’s requirements.

UNM has found its RTTMS system to be a very valuable decision-making and management tool. “The district energy system is partially financed with bonds. Our investment in an RTTMS system plays a key role to ensure our projected revenue streams are not sent awry by an unexpected capital investment,” says Zumwalt. “Had we known about the extensive benefits of RTTMS earlier, UNM would probably had saved about $500,000 in the deployment of instrumentation.”

After the RTTMS system is cali-
brated, as is required, current
experience suggests comparable
accuracy to that of instrumenta-
tion.

University of New Mexico The University of New Mexico (UNM)

in Albuquerque began using RTTMS in 2006, a move the university considered the “crowning energy conservation project” after completing a major district energy system upgrade between 2001 and 2006. The system serves more than 100 buildings with 5. 7 million sq ft (525,000 sq m) of space on a 600-acre ( 2.5-sq-km) campus.

According to Jeffrey Zumwalt, associate director of UNM Utilities, “The university regularly adds or removes loads (buildings) to its existing district energy distribution system. We have an obligation to ensure these changes can be accommodated without negatively impacting the existing customers. That initiated our search for an RTTMS system.”

UNM uses RTTMS for numerous purposes, like managing/operating valves,

and validating external consultants’ and contractors’ work. UNM has adapted its RTTMS software to serve as an internal standard for all hydraulic and thermal modeling, which means external consultants must prove their hydraulic and thermal calculations by using the UNM RTTMS system. In addition the RTTMS system was a key tool used to the successful commissioning of the second gas turbine put into operation. UNM has not made a detailed quantification yet; however, indications point to a return on investment within 18-24 months from startup of the RTTMS operation

Using RTTMS has enabled UNM to gain significant knowledge about its steam and chilled-water systems. For example, the TERMIS RTTMS solution chosen by the university recommended closing one steam pipeline to the north area on the UNM campus to optimize the operation and delivery to that campus area. “We didn’t even realize the system would work fine without the pressure-reducing valve,” says Larry Schuster, utilities engineer and project manager of the UNM district energy rehabilitation project.

Because it monitors return temperatures, RTTMS also has been useful in optimizing delta T. “We monitor the temperatures to ensure optimal balance of demand and supply,” explains Schuster, “but we do not have direct control of them. Another area of the physical plant is responsible for building operations,

Copenhagen Energy

Copenhagen Energy is a distribution company of thermal energy and gas, based in Copenhagen, Denmark, that distributes steam, hot water and chilled water to 30,000 commercial, industrial and residential buildings from an installed thermal energy capacity of 1,500 MW. The company’s steam system has underground piping and also condensate return distribution piping. The steam is purchased and supplied from three ultra-low-emission combined heat and power facilities of private energy providers DONG Energy and Vattenfall AB. The hot water system has underground piping, with the hot water purchased and supplied from transmission providers CTR (Metropolitan Copenhagen Heating Transmission Co.) and VEKS.

The company is now converting the steam-based distribution system to a hot water distribution system. The company, which began using TERMIS RTTMS software in 2006, used modeling information from the program as the basis for its 2007 decision to make the conversion. The information assets created during the feasibility study of the conversion now also serve as the platform for managing the planning, design and implementation of the conversion project.