$0

$20,000

$40,000

$60,000

$80,000

$100,000

$120,000

$140,000

100kW with No Heat Recovery

150kW with No Heat Recovery

150kW with 50% Heat Recovery

Net Possible Savings

Project By:

Soyoung Moon Advised By:

Prof. Melody Baglione

Optimizing Cogeneration Performance

Project Goals

Energy Efficiency

Data Analysis

Cogeneration, or combined heat and power (CHP), systems use heat engines to simultaneously generate electricity and useful heat. Power plants produce electricity but reject waste heat to the environment and have grid losses. By using on-site cogeneration instead of buying electricity from the utilities, efficiency is increased from around 40% to 80%.

Cogeneration System A study of the 150kW cogeneration plant at Cooper Union’s Foundation Building (FB) reveals that optimizing cogeneration plant operation could save an additional $64,000 annually. The goal is to work with facilities and vendors to implement changes in order to increase electricity production and heat recovery.

Cooper Union’s historic Foundation Building, built in 1859, underwent major HVAC renovations in 2010 including the installation of a 150kW cogeneration system. To minimize installation costs, the cogen system was connected in parallel with the boilers with common pumping and water treatment. Heat was originally dumped to the cooling towers. Subsequent water treatment and control issues caused multiple engine failures so the water loop was reconfigured in Spring 2016.

Future Work

Building Management System

February 2017

Conventional Generation Cogeneration

(Combined Heat and Power)

Example Total Efficiency 47% 80%

System Overview Foundation Building Cogeneration

Overview New Cogeneration System Flow Diagram

The Building Management System (BMS) is a computer-based control system that monitors and controls the operation of the HVAC system.

Original Cogen System Configuration

Potential Savings of $64k v  Analyze pumping and heat recovery performance with newly installed higher capacity pump

v  Update BMS to reflect new system flow schematic and set up automated trending of data

v  Develop analysis tools to track electrical and thermal performance

Buildings have two major energy demands: electrical and thermal. In conventional generation, electrical demands are met by purchasing electricity from a utility grid and thermal demands are met by purchasing natural gas and running boilers.

Without Cogeneration

Original Heat Dump Heat Exchanger repurposed as Heat Recovery Heat Exchanger

Assumed utility rates and maintenance: Electric – $0.2/kWh, Gas – $0.85/therm, Maintenance - $0.0375/kWh

Source: BMS Real Time Data (10/10/2016)

New Intelligen Modbus data integrated into the BMS

*Units in this figure represent units of useful energy.

With Cogeneration

Converting chemical energy to electrical energy produces significant waste heat. In conventional systems, waste heat is lost to the environment because transporting heat over large distances is impractical. With cogeneration, the released heat is recovered to meet the building’s thermal demand.

Building Hot Water

Pumps in Basement

$64k

$96k

$128k

Source: P. a. L. B. H. P. Milton Meckler, Sustainable On-Site CHP Systems, McGraw-Hill, 2010. Print.

Pump and check valve

were installed in wrong directions and had to be reconfigured

Cogen Heat Exchanger

Pump

$64k in potential annual savings identified: 1.  Increase run load to 150 kW by

installing current transformer to track building electrical load 

2.  Analyze hot water loop and determine boiler set-points to optimize heat recovery

To improve operation, a dry cooler was installed to isolate the cogen coolant water from the building’s hot water. The original heat exchanger, plumbing and pump were repurposed but ultimately the pump failed. It was also observed in April 2016 that the boilers were firing while the cogen system was dumping heat.

3-Way Valve