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A comparison of different heating and cooling energy delivery systems and the Integrated Community Energy and Harvesting system in heating dominant communities

The building sector is one of the largest consumers of energy and producers of greenhouse gas emissions in Ontario, representing 13% of the province’s emissions. Recently, countries have been looking to decrease their emissions in response to climate change. The electrification of space heating and domestic hot water preparation has gained traction in reducing emissions in countries with low emission electricity grids. This thesis proposes a novel energy delivery system called the Integrated Community Energy and Harvesting (ICE-Harvest) system. The ICE-Harvest system is a modified 5th Generation District Heating and Cooling (5GDHC) system. An ICE-Harvest system, much like a 5GDHC system, is a district energy system that incorporates heat pumps to couple the thermal and electrical energy demands of buildings. The ICE-Harvest system uses heat pumps to supply both heating and cooling from a one pipe thermal distribution network. The ICE-Harvest system has unidirectional mass flow in a ring arrangement with branches at each building. Bidirectional energy flow between the network and buildings is permitted, meaning that heat rejection from cooling processes can be recovered in the network to reduce the total system heating load. This concept is referred to as energy sharing.
The energy needs of the network, and thus the buildings, are serviced through a centralized generation station referred to as the Energy Management Center (EMC). The EMC regulates the supply temperature of the network to the controlled setpoint. Within the EMC, the primary generation source is a Combined Heat and Power (CHP) unit. The purpose of this CHP is to offset the existing centralized natural gas generators on the Ontario electrical grid. These gas generators operate intermittently and inefficiently as a form of dispatchable generation to stabilize the provincial electrical grid. In this research, it is proposed that ICE-Harvest systems with on-site CHPs could replace these gas generators while providing the same support to the electrical grid at a much higher energy utilization ratio. For an accurate comparison, the CHP is constrained to only turn on according to the electricity system operator's gas generator dispatching schedule. An auxiliary boiler is included in the EMC to provide heat when the CHP is not permitted to operate. However, the possibility for Thermal Energy Storage (TES) to replace this boiler is also explored.
An ICE-Harvest system's ideal design depends on the market conditions, building energy demands, and available waste energy sources. This research presents an ICE-Harvest system in a heating demand dominated community located in Ontario, Canada. The community consists of five buildings. The ICE-Harvest system is compared to conventional and alternative building energy systems using the energy consumption data of these buildings. The systems are compared according to their energy consumption, emissions produced, and impact on the electrical grid at both the distribution and transmission levels. The topic of using thermal energy storage in ICE-Harvest systems is also discussed, and a parameter sweep is performed on the thermal energy storage capacity. The results show that the ICE-Harvest system offers demand management opportunities to electricity system operators, substantially reduces annual emissions, and offers improved energy utilization compared to conventional systems. / Thesis / Master of Applied Science (MASc)

Identiferoai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/26162
Date January 2020
CreatorsSullivan, Brendan
ContributorsCotton, James, Lightstone, Marilyn, Mechanical Engineering
Source SetsMcMaster University
LanguageEnglish
Detected LanguageEnglish
TypeThesis

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