CO₂ Refrigeration the ‘Coolest Competitor’ at 2022 Beijing Olympics

CO₂ refrigeration has confirmed to be an efficient resolution in a number of use instances. Lately, R-744 discovered itself on the grandest athletic stage of all of them – the 2022 Beijing Olympics – the place it earned a proverbial gold medal for its cooling efficiency, effectivity, and sustainability.

A Worldwide Dedication to Local weather Motion

The Beijing Organizing Committee, at the side of the UN Sports activities for Local weather Motion Framework, established two overarching targets getting into the occasion: To set a transparent trajectory for sports activities communities to fight local weather change and to make use of sports activities as a unifying software amongst residents worldwide for local weather motion. After exhaustive analysis, transcritical CO₂ methods had been chosen for his or her effectivity, efficiency, and sustainability. The 2022 occasion marks the primary time in historical past a CO₂ refrigeration system was used to create ice on the Winter Olympics.

4 ice rinks on the 2022 Beijing Olympics utilized CO₂ methods, together with the Nationwide Velocity Skating Oval, Capital Indoor Stadium, Capital Brief Monitor Velocity Skating Coaching Corridor, and Wukesong Ice Hockey Coaching Corridor.

CO₂ refrigeration operates with a cooling effectivity that’s 1.2 occasions increased than conventional hydrofluorocarbon (HFC) refrigerants and may keep a temperature consistency of 0.5°C or much less throughout all ice surfaces, retaining the floor clean.

By choosing CO₂ refrigeration, the Olympics’ sustainability efforts would have the equal carbon results of three,900 cars off the street or the planting 1.2 million bushes.

“The Olympic Video games are at the beginning a sporting occasion, however with their international visibility, additionally they present an necessary platform to showcase sustainable options,” mentioned Marie Sallois, IOC director for sustainability, in a press launch.

HIGHLY EFFICIENT: CO₂ refrigeration operates with a cooling effectivity that’s 1.2 occasions increased than conventional hydrofluorocarbon (HFC) refrigerants and may keep a temperature consistency of 0.5°C or much less throughout all ice surfaces. (Courtesy of Unsplash)

Transcritical CO₂ Refrigeration

CIMCO Refrigeration, a refrigeration contractor based mostly in Burlington, Ontario, Canada, served as a guide for the Olympics. Based mostly on the corporate’s experience, it really useful 1,000 TR, based mostly on 5°F suction and 100°F condensing. These transcritical CO₂ methods included:

• Six skids, every with six compressors, offering roughly 190 TR at minus 18°C SST and 38°C SCT;
• Six adiabatic fuel coolers, one per skid;
• 4 CO₂ re-circulator vessel packages, every full with two CO₂ pumps;
• Vessels related to widespread suction and customary liquid drains;
• A flooring design consisting of 10 refrigerated flooring zones, together with two monitor zones and two arenas with devoted pumping methods. The opposite six zones related into two pumping methods however with particular person zone valves and temperature management; and
• A flooring community constructed of stainless 20-mm (3/4-inch) pipe and stainless headers sized to the stream price.

Consideration to Element

When putting in or commissioning a CO₂ refrigeration ice system, Jason Hill, coaching, growth, and commissioning with CIMCO, creates a guidelines.

“It’s at all times electrical first,” mentioned Hill on the Refrigeration Mentor podcast . “We first guarantee {the electrical} connections are tight – even when the unit is coming immediately from the producer, as a result of these methods come from a whole lot of miles away. Then, it’s dry testing, ensuring all the pieces is stroking the best way it ought to, checking bolts, inspecting compressor connections, conducting strain testing, and so on. And at all times have one other man with you to double- and triple-check all the pieces in your guidelines, together with triple evacuation, placing within the preliminary filters and drier cores, guaranteeing strainers are clear, and so on., as a result of you may by no means be too secure.”

When it comes time to put and keep the ice, ambient and floor temperatures are crucially necessary.

“To begin making ice, we’d like the slab temperature to be round 16°-19°F,” Hill mentioned. “Whenever you get to the location, if the ambient circumstances are barely totally different than no matter was uploaded on the manufacturing facility, you will have to make a minor tweak. Be sure you know which bottles are vapor and liquid and weigh them so you understand precisely how a lot you’re placing within the system.”

BE IN CONTROL: Pay shut consideration throughout testing to make sure controls are arrange correctly. (Courtesy of Unsplash)

Establishing and managing the controls of a CO₂ system is necessary as effectively. It’s necessary to pay shut consideration throughout testing to make sure all the pieces is working as deliberate.

“We depend on the producers’ set factors, and we’ll at all times affirm the software program matches and has acquired the newest updates,” mentioned Hill. “Every system has distinctive controllers — they’re not going to be the identical on any two methods. For instance, with fuel coolers, there are oftentimes two controllers — one for the followers and one for the water — and every must be arrange to ensure all the pieces’s working correctly. With the followers, you should know the efficiency temperature at 30%, 70%, and so on. And for the water, you should know when the solenoid ought to open – these are issues you could be taught by testing.”

CO₂ transcritical ice rinks are chock stuffed with distinctive challenges and hurdles, and Hill mentioned it’s necessary for techs to pay attention to these earlier than ever stepping on the job.

“These are very totally different initiatives than artificial packages or ammonia methods – we’re hitting temperatures I’ve by no means seen earlier than,” Hill mentioned. “The common provide and return temps are 12°-19°F. A 12° provide will sometimes have a Delta of 4°, in order that’s a 16° return. However among the CO₂ rinks we’ve handled are getting down to six°F, which goes to offer you a 11°-12° return.

“Each hour or hour and a half, a flood is going on on the floor, and you need to make sure the ice units up correctly – not too fast or too gradual,” continued Hill. “Getting it good is a problem – it’s like an artwork.”

Even with all of his expertise, Hill at all times expects the surprising.

“I’ve been within the business fairly some time, and almost day-after-day, I see one thing on these packages that makes me go, ‘wow,’” he mentioned. “And I like that form of stuff as a result of it retains me from losing interest. You be taught one thing new on each undertaking, which is fairly cool.”

CO₂ refrigeration is new to many HVAC contractors, and Hill encourages apprentices and rookies to be as curious as potential when studying on the job.

“If a tech has any questions, they shouldn’t hesitate to ask them,” mentioned Hill. “In the event that they don’t perceive what this does, that does, or how issues differ on a specific package deal — they should understand it’s OK to ask questions. Decide the brains of the fellows who’re there and perform some research afterward. Research the handbook if you get again to your resort room. Find out how issues work and what they’re designed to do. You’ll be higher off due to it.”