Knowledge base
In short
A dual-fuel or hydrogen-ready engine can run on more than one fuel, and the way its heat divides between the jacket, the charge air and the oil can change with the fuel. The radiator therefore has to cover every mode the engine may run in, not only the usual one. For an engine that will be converted to hydrogen later, the cooling plant is best planned with that step in mind, so the radiator does not become the reason the conversion is delayed.
More and more enquiries for gas engine plants now carry a short line in the specification: the engine is hydrogen-ready, or the plant must be able to switch fuels. For the radiator that line matters more than it looks. The engine data sheet most buyers send covers one fuel at one load, and the cooling plant designed from it covers that case well. This guide explains in plain words why an engine that can burn more than one fuel asks a little more of its cooling plant, and what information helps the maker get it right the first time.
What The Labels Mean
A dual-fuel engine runs on gas with a small amount of liquid fuel to light it, and it can usually change over to liquid fuel alone when the gas supply is lost. Ships, island grids and plants with an unreliable gas line use them for exactly that reason. A hydrogen-ready engine is a gas engine that can take a share of hydrogen mixed into its natural gas, or that has been prepared to be converted to run on more hydrogen at a later date.
The word ready is used loosely in the market. For one engine it means it runs on a blend today; for another it means a set of parts will be changed in a future overhaul. The engine maker's documents say which, and that is the first thing we ask to see.
Why The Fuel Changes The Cooling Duty
An engine turns part of its fuel into power and the rest into heat, which leaves through the exhaust, the jacket water, the charge air and the oil. The share each one takes is not fixed. It depends on the way the fuel burns, on the air the engine is given and on how the engine is tuned for that fuel. Change the fuel and the split moves, sometimes toward the jacket, sometimes toward the charge air.
Hydrogen burns faster and ignites more easily than natural gas, so engines running on it are tuned to keep combustion calm, and cooler charge air is one of the tools for that. On a dual-fuel engine the liquid fuel mode and the gas mode each have their own heat balance, and the engine may also be allowed a different output in each. The radiator sees all of this as different duties on the same circuits.
Every Mode Has To Be Covered
The cooling plant cannot choose which mode the engine runs in on the hottest afternoon of the year. If the gas supply fails in summer and the engine changes over to liquid fuel, the radiator has to carry that case at that moment. The same is true for an engine that runs on a hydrogen blend in some months and on natural gas in others. So the design is checked against every mode the engine may run in, and the hardest one decides each circuit.
This is where most first enquiries fall short: only the main fuel is sent. Ask the engine maker for the heat data of each fuel mode, or for a statement that the circuits stay the same, and send both with the enquiry. It costs a day at the start and saves a redesign later.
Planning Now For A Conversion Later
An engine bought as hydrogen-ready may run on natural gas for years before the hydrogen arrives. The radiator will usually still be in place on the day of the conversion, and it should not be the part that holds it back. Where the future data is already known, the radiator can be designed for both cases from the start. Where it is not yet known, it helps to leave space and connections on the site so that a coil section or a unit can be added without moving everything else.
Sites that handle hydrogen may also have areas where electrical equipment has to meet explosion protection rules. If the radiator, its fans or its cabling stand in or near such an area, the maker needs to know before the fan motors are chosen.
TECS Engineering designs and builds radiators and LT/HT radiators for gas, dual-fuel and diesel engines. Send the engine data for each fuel mode and the site conditions, and TECS does the calculation for every case the engine may run in.
In Short
- Dual-fuel engines run on gas and can change over to liquid fuel
- Hydrogen-ready can mean a blend today or a conversion at a later overhaul
- The heat split between jacket, charge air and oil can change with the fuel
- The radiator must carry every mode, including the hottest day in the hardest mode
- For a later hydrogen conversion, plan the cooling plant and the site space now
- Hydrogen sites may set explosion protection rules for fans and cabling
What To Send With An Enquiry
- Engine make and model and the fuels it may run on
- Engine data sheet for each fuel mode, or the heat duty, flow and temperatures of each circuit per mode
- Whether a hydrogen conversion is planned, and the engine data after it if known
- Site ambient on the hottest day, altitude and the kind of air on site
- Any area on site with explosion protection rules near the radiator
- Sound limit, fan power supply and the space available for the radiator
Questions We Are Often Asked
Does a hydrogen-ready engine need a different radiator?
Not always a different one, but one checked against the engine data for hydrogen as well as for natural gas. The heat split between the circuits can change with the fuel, and the radiator has to cover both.
What does dual-fuel mean for the cooling system?
The engine has a gas mode and a liquid fuel mode, each with its own heat balance. The radiator is designed so that it carries the harder of the two on the hottest day.
Can an existing radiator stay when the engine is converted to hydrogen?
Sometimes. It depends on how the engine data changes after the conversion. Send the old radiator data and the new engine data, and the existing unit can be checked before anything is replaced.
Which engine data should I ask the engine maker for?
The heat duty, flow and temperatures of each cooling circuit for every fuel the engine may run on, or a statement that they do not change between modes.
Does a hydrogen site change the fan motors?
It can. If the radiator stands in or near an area with explosion protection rules, the fan motors and cabling have to meet them, so the site classification belongs in the enquiry.
Contact Us
Send us the heat duty, the fluid temperatures and flow rates, the ambient conditions and the installation limits. We answer with a design proposal - or write to us on WhatsApp.
