Do you know what percentage of the electricity used by your factory is consumed by cooling/heating source systems? The percentage is higher than you would expect (between 20% and 50% according to Mitsubishi Heavy Industries Thermal Systems’ research). And yet, not many clients have implemented, or are considering implementing, steps to improve the efficiency of their cooling/heating source systems.
The manufacturer had nearly given up on trying to reduce the energy used by its factory. How could it reduce the energy used by its cooling systems?
The chemical manufacturer “T” that is the subject of this case study was no exception. Having set targets for reducing carbon dioxide emissions and energy conservation, the manufacturer replaced its air-conditioning equipment and lighting with more energy-efficient models. Looking for ways to make further energy savings, it then attempted to monitor how much power was being consumed by its cooling systems, but was unable to do so because it lacked the systems and equipment necessary to visualize the status of its systems.
If only it were simpler to visualize the status of cooling systems
After researching the topic, the manufacturer “T” found that in order to determine how much electricity was being consumed by its cooling systems, it needed to be able to accurately monitor the equipment’s operational status. However, analyzing the chiller log required specialist knowledge, and it was unrealistic to expect the employees responsible for equipment and operations, busy as they were, to go to the effort of analyzing chiller logs. Time ticked on without any specific action being implemented.
Steps to a Solution
Cooling system consumed a high percentage of the energy used in the factory. Focusing on this issue, Mitsubishi Heavy Industries Thermal Systems (referred to as “MHI Thermal Systems”), having been approached by the manufacturer, decided to implement a solution that would improve the efficiency of the cooling system as a whole, rather than its individual equipment. This involved:
- Quantifying and numericizing all aspects of the operational status of the existing cooling equipment and reassessing the performance of the entire cooling system;
- Proposing an optimization of system configuration in the interests of energy efficiency;
- Proposing more energy efficient modes of operation;
- Performing monitoring and improvements continuously;
- Proposing multiple unit control (optimal unit number control systems)
Mitsubishi Heavy Industries’ Chiller and air-conditioning equipment solution enabled the visualization and assessment of the performance for the cooling/heating source systems
- The solution made it possible to quantify and numericize log data from the client’s chiller in order to gain a precise understanding of system status.
- The solution also made it possible to calculate power consumption and electricity cost both by individual equipment and for the chilling system as a whole, assess energy efficiency, and perform accurate energy efficiency predictions.
- The solution enabled the calculation of the greenhouse gas emissions of the cooling/heating source systems as a whole, based on operational status data.
Replacing existing systems to achieve the most energy efficient system configuration
- MHI Thermal Systems’ solutions calculated the necessary cooling/heating capacity for the factory overall, and proposed a review of the system configuration, including existing chillers, in order to improve energy efficiency.
- To aid the review of the system configuration, the engineering team in MHI Thermal Systems took into account equipment shutdowns during maintenance and replacement, as well as future projected load increases.
Proposal from MHI Thermal Systems’ engineering team on diagnosis, repair, and replacement of related equipment
- When implementing changes to system configuration, MHI Thermal Systems also inspects ducts and other associated equipment, and proposes the repair or replacement of any equipment that has deteriorated with age or is decreasing chilling efficiency.
Proposing Operational Modes that Improve Energy Efficiency
- Based on its assessment of operational status, MHI Thermal Systems will propose improvements to the mode of operation.
- MHI Thermal Systems then presents you with an optimized plan for operating your water chilling plant.
- The “Ene-Conductor” from MHI Thermal Systems does away with the need for complex control arrangements, and automatically exerts optimum control over the entire system.
Continued Monitoring and Proposal of Solutions
- A program of continuous monitoring after the initial consultation makes it possible to perform more precise analysis by comparing performance over time, and based on the outcomes of this analysis, MHI Thermal Systems provides ongoing support in the mid-to long-term, to enhance the performance of the cooling/heating source systems.
Achievement of Energy Targets
- By ensuring the system continues to operate on the basis of precise energy efficiency predictions, it is possible to achieve energy-saving goals.
Reasonable Reductions in Greenhouse Gas Emissions
- The optimization of energy efficiency through a review of system configuration will reduce greenhouse gas emissions.
Improvement of return on investment for cooling/heating source systems as a whole, including associated equipment
- The solution extends the lifespan of the cooling/heating source systems and improves return on investment.
The proposal from MHI Thermal Systems enabled the client to successfully reduce the energy usage of its factory.
A representative of the chemical manufacturer “T” said, “The energy savings achieved were such that the actual performance of the system was exactly as projected in the proposal. We have also become able to better visualize the status of the system, and intend to focus on these numbers in the future as we attempt to make further improvements in energy efficiency. We will continue to consult Mitsubishi Heavy Industries Thermal Systems to see if there are any other areas in which we can make energy savings.”
Ene-Conductor: Heat Source Control System
The Ene-Conductor from Mitsubishi Heavy Industries Thermal Systems is a chiller control system for controlling turbo chillers and associated cold water pumps, cooling water pumps, and cooling towers. The Ene-Conductor packs the unparalleled expertise in chiller control of chiller manufacturer Mitsubishi Heavy Industries into a single package, allowing superior control of chiller equipment. By exercising optimal control over the system as a whole, the Ene-Conductor maximizes chiller performance, delivering overall electricity savings of around 65% compared to existing turbo chiller systems, and otherwise contributes to significant reductions in CO2 emissions in office buildings, commercial premises, and factories.