COOL4 SEA & INDUSTRY (C4S&I), a cooling technology company, has developed a sustainable cooling technology where waste heat is efficiently utilised to produce cooling onboard ships and within industry. Grundfos has worked with C4S&I, supplying pumps, sensors and control solutions and consultancy to optimise their absorption chillers.
The C4S&I absorption chillers are the only ones in the world optimised to handle the dynamic motion often found on ships and the fluctuating temperature conditions at sea, and which are also present in a broad range of industrial applications. This opens up new avenues for utilising absorption chillers that, with a COPelec (Coefficient Of Performance) factor of 30-35, can reduce electrical consumption for cooling by 90%.
We initially contacted Grundfos as a supplier of pumps. However, the discussion quickly grew into a collaboration with Grundfos. Together, we developed our solution even further than expected, making it even more resilient and energy efficient.
The situation
In order to scale production, C4S&I was looking for alternatives to their expensive chemical pumps and wanted to switch to Grundfos MAGdrive pumps for pumping their high salinity lithium bromide solutions (up to 60% concentration). C4S&I needed a solution that could manage very high densities and operate efficiently under challenging conditions, such as pumping liquids at boiling points from a suction tank with an internal pressure close to absolute vacuum. Daniel initially received a standard MAGdrive pump but was looking for higher performance to meet his specific needs. The challenge was to enhance the pump’s performance without causing cavitation issues.
“A Grundfos lecture on frequency control hosted by SIMAC was my first exposure to Grundfos E-pumps, where the pump is powered by a variable speed-controlled MGE motor, which substantially increases efficiency. Up to that point, we had only used standard pumps.”
Daniel Buhl Hansen, CEO and Partner, COOL4 SEA & INDUSTRY
SIMAC is the Svendborg International Maritime Academy, a maritime institution for education and knowledge development in Denmark. At the event, Grundfos presented how to utilise frequency converters to optimise pump control and sizing, and how the MGE motors can combine this with pump and process control functionalities. This helped Daniel realise the opportunity in the MGE motor to enhance pump performance in regard to functionality and cavitation.
The Grundfos solution
Starting with an E-pump solution, the Grundfos Customer Service Unit (CSU) worked closely with C4S&I to provide technical expertise, customised CRNE MAGdrive pumps and access to a wider portfolio of Grundfos solutions and experts. They worked on improving the pump hydraulics, integrating Grundfos sensors and utilising the MGE motor for better control and flexibility. The technical collaboration with C4S&I began by addressing optimisation potential in pumps, which led to the development of a customised CRNE MAGdrive pump that used a larger impeller to improve suction and flow combined with a low-speed MGE motor.
Grundfos CSU is an internal support function that offers a range of technical services to help transform customer demands into customised product solutions. They offered extensive support in optimising the system setup, ensuring the pumps could handle the specific requirements and overcome obstacles.
For example, switching to MGE motors was not a straightforward process, and there were several calls to resolve challenges. The prompt assistance from Grundfos enabled the smooth transition from regular motors to MGE motors. Challenges such as leakage current, communication between pumps, IP address setup, sensor setup, GSC file setup and familiarisation with GO Link required support and knowledge sharing. This was also true when addressing corrosion concerns and utilising sensors for pressure, temperature and conductivity measurements.
“We experienced that Grundfos worked closely with us to understand our specific needs and challenges, and we got to discuss with corrosion specialists and sensor developers. We felt that Grundfos ensured comprehensive coverage of all aspects of our project."
Daniel Buhl Hansen, CEO and Partner, COOL4 SEA & INDUSTRY
CSU conducted extensive testing to collect data on pump performance, with a particular focus on cavitation and flow rates. This data-driven approach informed further optimisation of the absorption chiller design, controls and cooling power.
- Technical approach: The CSU team focused on combining existing components in innovative ways. They used a larger impeller in a smaller CRNE pump using the variable speed of the MGE motor to enhance performance. This approach required careful balancing to avoid cavitation while maximising flow.
- Testing and validation: The team conducted thorough testing, including NPSH (Net Positive Suction Head) curves at various speeds, to ensure the pump could operate efficiently without cavitation. This data was crucial for optimising the pump’s performance, as the pumped liquid is constantly at boiling point due to pressure close to absolute vacuum.
The outcome
The challenges encountered throughout the project were successfully addressed through a combination of technical expertise, collaboration and innovative solutions. These approaches were instrumental in overcoming hurdles and achieving the desired outcomes. C4S&I could now monitor and control the system more effectively, leading to better operational performance.
- Improved cooling performance: The reconfigured pump provided better suction and higher flow rates
- Technical support: Continuous technical support and access to various experts ensured system optimisation
- System upgrade: The system was upgraded from using external frequency converters to integrated MGE motors, simplifying the control setup and improving reliability
The impact of the collaboration with Grundfos on the final solution was significant. The system's physical size was reduced by an impressive 75%. The flow rate and heat transfer efficiency (Q/H) were notably improved. The solution achieved significant advancements in avoiding cavitation, thanks to insights gained from the experience Grundfos had from other low-suction pressure applications and due to the customised hydraulic setup in the pumps. The control system and electrical wiring were simplified by leveraging the built-in functionalities of the MGE motor.
Moreover, the partnership allowed for comprehensive collaboration in developing an advanced heat estimation function for the absorption chiller. Enabling the estimation of heat absorbed, cooling power produced and electrical power consumption. These new features significantly help the end user document energy savings, CO₂ reduction and environmental reporting.
Collaboration with Grundfos
Industry CSU and C4S&I resulted in:
- System size reduced by 75%
- Improved performance and reduced operational costs for end-users
- Enhanced reliability and reduced maintenance needs
- Better monitoring and control capabilities
- Cost savings achieved by utilising MGE functionality and Grundfos sensors, reducing the need for external components
“The collaboration with Cool4Sea is an excellent example of Grundfos being more than just a supplier of pumps; many of our experts supported the product development. What we achieved was made possible due to the work of the Industry CSU department who got involved early in the process. They had direct communication with Daniel to test and develop the product using our pumps, sensors and control units."
René Møller Pedersen, Sales Engineer Industry, Grundfos
Benefits of collaboration for small OEMs
Looking towards the future, working with C4S&I provided valuable learning opportunities for Grundfos. It also highlights the innovative capabilities of Grundfos in solving complex technical challenges. Using Grundfos as a partner in developing and improving systems, OEMs can gain access to technical expertise and a wide portfolio of pumps, sensors and controls. Tailored solutions from the CSU team and full utilisation of products and features can help build partners’ business further.
“Our partnership with Grundfos has improved our system significantly, in terms of its sustainability profile, and also because Grundfos was able to point out areas to improve that we could not initially see ourselves. Jonas Kildedal from CSU and the other Grundfos experts helped us overcome significant technical challenges, leading to improved efficiency and reduced costs and emphasising the value of collaboration and the benefits of working with a knowledgeable partner. As our company grows, these benefits help us scale production and our business!”
Daniel Buhl Hansen,CEO and Partner, COOL4 SEA & INDUSTRY
About the Grundfos CRNE:
COOL4 SEA & INDUSTRY – Active Spray Absorption technology
Function:
The Active Spray Absorption cooling technology functions by utilising waste heat at temperatures between 65-90°C to produce cooling for air-conditioning or process cooling at temperatures down to 8°C . As waste heat is the prime energy source, the need for electricity is reduced up to 90%.
Cooling power: 250kW
Thermal efficiency: 65-70%
COPelec: 30-35