- #1
voltech444
- 32
- 1
I bought a A/C scroll compressor from a 2005 Toyota Prius. I want to convert it into a expander to use in a ORC waste heat recovery system. If I can get it working on the bench, then it's my dream to put it on a hybrid vehicle, most likely another Prius since I own 2. The electricity it generates can be fed back into the battery to significantly increase the efficiency. From what I understand a scroll compressor and expander are nearly identical, the scrolls are the same, there's a check valve that needs to be removed from the compressor and a few other small modifications. These compressors for hybrid/electric vehicles are perfect because they have a brushless permanent magnet motor which also makes a great generator. From information I've read, the Prius compressor has a maximum output of 4.3Kw.
To increase efficiency I could connect another expander in series with the first to make a 2-stage expander system. I plan on using the condenser from the Prius and the 2 electric fans that come with it. I need to design and build the heat exchanger that goes in the exhaust. I also want to utilize heat from the engine cooling system, so perhaps a small heat exchanger that connects to the engine coolant system. I'm also comparing if I should have the refrigerant flow through the heat exchangers directly or use a liquid coolant loop with automotive anti-freeze. Having only the refrigerant flow through heat exchangers is a simpler system with less parts, so that's what I'm leaning towards.
The liquid refrigerant is pumped by a small pump (centrifugal I think, there's probably a few options for that) into the first heat exchanger (this exchanger has coolant from the ICE flowing through it, it goes before the ICE radiator to get the most heat) it then goes into the second heat exchanger in the ICE exhaust system. Then it is expanded through the scroll expander which generates electricity which is fed back into the hybrid battery. Then the refrigerant goes through the condensor where it is cooled down and turns back into a liquid and the cycle starts over.
The motors on these compressors are 3-phase permanent magnet AC. The AC power would have to be rectified into DC and then go into a DC-DC converter that can boost it to the proper voltage to feed into the battery.
These expanders could be used to generate electricity from any waste heat source and solar. There are literally thousands of these for sale from junkyards, and most of them are just sitting there, they are so reliable they are not having many failures in vehicles, and if they do they car is well over 200k. I've always wanted to get a scroll expander to build a waste heat ORC system, but they're expensive starting at $5k for a 5Kw. I see an opportunity here to make use of all these hybrid scroll compressors that are just sitting and deteriorating in junk yards (it makes me so sad
, but excited if we could find another use for them
)
I'm not a mechanical engineer, I run my own company repairing hybrid and electric vehicles, so I have to approach this by just building and trying things. I want to figure out as many of the details I can before I start putting things together, but this will probably be mostly by trial and error.
Any input into this matter is greatly appreciated, thank you for reading!
To increase efficiency I could connect another expander in series with the first to make a 2-stage expander system. I plan on using the condenser from the Prius and the 2 electric fans that come with it. I need to design and build the heat exchanger that goes in the exhaust. I also want to utilize heat from the engine cooling system, so perhaps a small heat exchanger that connects to the engine coolant system. I'm also comparing if I should have the refrigerant flow through the heat exchangers directly or use a liquid coolant loop with automotive anti-freeze. Having only the refrigerant flow through heat exchangers is a simpler system with less parts, so that's what I'm leaning towards.
The liquid refrigerant is pumped by a small pump (centrifugal I think, there's probably a few options for that) into the first heat exchanger (this exchanger has coolant from the ICE flowing through it, it goes before the ICE radiator to get the most heat) it then goes into the second heat exchanger in the ICE exhaust system. Then it is expanded through the scroll expander which generates electricity which is fed back into the hybrid battery. Then the refrigerant goes through the condensor where it is cooled down and turns back into a liquid and the cycle starts over.
The motors on these compressors are 3-phase permanent magnet AC. The AC power would have to be rectified into DC and then go into a DC-DC converter that can boost it to the proper voltage to feed into the battery.
These expanders could be used to generate electricity from any waste heat source and solar. There are literally thousands of these for sale from junkyards, and most of them are just sitting there, they are so reliable they are not having many failures in vehicles, and if they do they car is well over 200k. I've always wanted to get a scroll expander to build a waste heat ORC system, but they're expensive starting at $5k for a 5Kw. I see an opportunity here to make use of all these hybrid scroll compressors that are just sitting and deteriorating in junk yards (it makes me so sad


I'm not a mechanical engineer, I run my own company repairing hybrid and electric vehicles, so I have to approach this by just building and trying things. I want to figure out as many of the details I can before I start putting things together, but this will probably be mostly by trial and error.
Any input into this matter is greatly appreciated, thank you for reading!