Absorption coolers use heat to regenerate their refrigerant. Two common types are a water vapour-LiBr chiller, and an ammonia-water chiller (in fact Einstein patented a mini bar chiller design still used today that has no moving parts, using just helium or hydrogen and gas absorption/evaporation to move refrigerating gasses around)
Single effect chillers have a low Coefficient of Performance (CoP) roughly around 0.4-0.6, meaning for every watt of heat you apply to a single effect chillers, you move 0.4-0.6W of heat, but they only need a minimum of 90⁰C in heat to power them.
Double effect chillers can reach 0.9-1.2 CoP.
Flue gasses are typically hotter than 90⁰C, so you’ll often see absorbers part of combined heat and power systems. Cooling in the summer, heating in the winter. All using waste heat from power generation.
What I find the most fascinating about them is they work using heat. The only power you need to apply is for a few pumps to move fluids around at low pressures, otherwise the primary refrigeration energy comes from heat regenerating the refrigerant.
I’ve often wondered what a district cooling system using these would get for efficiency if you colocated it with something energy hungry like a cement kiln or glass kiln.
Video of how a double effect chillers works
Edit: these are used already for district cooling, just usually for a campus like a university or government complex. The big benefit is you can run them on marginal heat sources, even off of low grade geothermal.
Whoah dude, I don’t know, you’re rapidly saying many numbers without connecting the sentences, what is your point? So either you can get the required chilling capacity using a relatively low amount of electricity, or using a shit ton of captured waste heat. Building a big plant just so you can run a chiller on the waste heat is probably not the most logical path. And now you’re also capturing the heat from power lines or what?
I guess the technology you mention makes sense where a lot of waste heat is consistently available for cheap, thanks for sharing the YSK, moving on.
Oh yeah I forget most people have no idea… Sorry about that.
What I’m saying is we’re throwing out fuck tons of free cooling and heating that we could otherwise use. Every house in North America could be cooled and heated with no extra fuel burned from the same power plants and industrial processes that supply them? Roughly speaking?
Why would you pay for electricity for cooling when a capital expense can get you that for essentially free? You don’t have to make the plant burn more fuel, you don’t have to interfere with how the plant runs, you can just tap off low grade heat and make chilled water to supply a town or city (Dubai uses district cooling if you want an example, although they use electric chillers)
This isn’t theoretical. It’s already used on earth and it works really well.
What I was trying to show with my numbers is the heat energy you need to burn for an equivalent amount of cooling isn’t that different compared to a electrical compressor chiller with a CoP of 3.5. 83MW of heat energy burned vs 60MW of heat energy for electric chillers. The difference is you don’t need to buy 83 MW of heat, whereas you need to buy the 20MW of electrical power (which took 60MW of heat) to run your chillers.
My other numbers were to demonstrate the eye watering amount of energy we discharge out of flue stacks and out of heat exchangers into rivers or lakes… If it’s hot enough, that energy can be used for heating and cooling but currently it goes up a stack.