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jeff5may · 09-25-16, 07:10 AM

That video is somewhat revealing, yet still vague and non-descriptive. Luckily, I am good at hunting down stuff like this... I found this chinese patent that describes the operation and intended performance of the manufacturing utility model. Between the video and the patent, it looks as if Gree has put a massive amount of r&d into this design. It obviously works well enough for them to include in production machines.

The compressor assembly has two rotary cylinders on a single shaft that are always working, with no switching of cylinders. The lower cylinder moves more volume than the upper cylinder. The compressor has three ports: suction, intermediate, and discharge. The intermediate port is connected as a tee between the two cylinders. It looks as if the intermediate port is being used as a suction line, and capacity and compression ratio of the compressor is varied by manipulating what goes into the compressor (at intermediate pressure) between cylinders. This is the same operating principle employed by the Acadia / Hallowell heat pumps. The main difference being that the Acadia used two separate compressors, where Gree has integrated two compression chambers into one shell.

At low dT, nothing is injected at intermediate pressure, and the two cylinders provide maximum BTU throughput at "normal R-410a" compression ratio. As working conditions change, some control (outside of the compressor) starts injecting gas into the intermediate port, which forces a shift in the way the compressor behaves. The interesting part is that the change in behavior can be tailored for an intended purpose! If the unit was designed for low ambient conditions, the compressor would shift into "bulldog gear", moving about the same BTU's at higher compression ratio (higher output pressure and/or lower suction pressure). OTOH, if the unit was designed for medium ambient conditions, the output pressure could be boosted without a major shift in suction pressure. This would lead to an increase in BTU throughput without much sacrifice in energy efficiency, if any. It all depends on what concoction exists OUTSIDE OF THE COMPRESSOR.

Now that I have an idea what the new compressor really is, it is obvious that Gree (and whoever is collaborating with them on this project) is breaking into ground that others have failed miserably at trying to conquer before. Hopefully the decade of design and testing they have done has yielded a product that is super durable. It needs to be to survive thousands of operating hours.

09-25-16, 07:10 AM	#12
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	That video is somewhat revealing, yet still vague and non-descriptive. Luckily, I am good at hunting down stuff like this... I found this chinese patent that describes the operation and intended performance of the manufacturing utility model. Between the video and the patent, it looks as if Gree has put a massive amount of r&d into this design. It obviously works well enough for them to include in production machines. The compressor assembly has two rotary cylinders on a single shaft that are always working, with no switching of cylinders. The lower cylinder moves more volume than the upper cylinder. The compressor has three ports: suction, intermediate, and discharge. The intermediate port is connected as a tee between the two cylinders. It looks as if the intermediate port is being used as a suction line, and capacity and compression ratio of the compressor is varied by manipulating what goes into the compressor (at intermediate pressure) between cylinders. This is the same operating principle employed by the Acadia / Hallowell heat pumps. The main difference being that the Acadia used two separate compressors, where Gree has integrated two compression chambers into one shell. At low dT, nothing is injected at intermediate pressure, and the two cylinders provide maximum BTU throughput at "normal R-410a" compression ratio. As working conditions change, some control (outside of the compressor) starts injecting gas into the intermediate port, which forces a shift in the way the compressor behaves. The interesting part is that the change in behavior can be tailored for an intended purpose! If the unit was designed for low ambient conditions, the compressor would shift into "bulldog gear", moving about the same BTU's at higher compression ratio (higher output pressure and/or lower suction pressure). OTOH, if the unit was designed for medium ambient conditions, the output pressure could be boosted without a major shift in suction pressure. This would lead to an increase in BTU throughput without much sacrifice in energy efficiency, if any. It all depends on what concoction exists OUTSIDE OF THE COMPRESSOR. Now that I have an idea what the new compressor really is, it is obvious that Gree (and whoever is collaborating with them on this project) is breaking into ground that others have failed miserably at trying to conquer before. Hopefully the decade of design and testing they have done has yielded a product that is super durable. It needs to be to survive thousands of operating hours.