Systems and methods for scroll unloading detection are provided and include a scroll compressor having a scroll compression mechanism. A controller determines a predicted discharge temperature of the scroll compressor, receives an actual discharge temperature of the scroll compressor, and compares the predicted discharge temperature with the actual discharge temperature. The controller also compares a speed of the scroll compressor with a speed threshold and detects unloading of the scroll compression mechanism based on the comparison of the predicted discharge temperature with the actual discharge temperature and based on the comparison of the speed of the scroll compressor with the speed threshold. The controller performs at least one of generating an alert and a remediating action in response to detecting the unloading of the scroll compression mechanism.

A device for generating electrical power, the device comprising a scroll expander with first and second scrolls configured to move relative to each other when a fluid is provided to an inlet at a higher pressure than a pressure at an outlet. The first scroll is configured to provide a magnetic field and the second scroll comprises one or more conductors in which electric currents are induced when the first and second scrolls move relative to each other.

A combined heat and power system according the present disclosure includes a Rankine cycle apparatus including an evaporator that heats a working fluid by heat exchange between the working fluid and a heat source medium, an expansion machine that converts expansion power of the working fluid into rotational power, and a condenser that cools the working fluid by heat exchange between the working fluid and a heat medium, and a thermal circuit for using the heat medium heated by the condenser. An expansion volume ratio of the expansion machine is equal to or less than an expansion ratio in a theoretical Rankine cycle determined based on a state of a temperature and a pressure of the working fluid at a discharge port of the expansion machine and a state of a temperature and a pressure of the working fluid at a suction port of the expansion machine.

A compressor may include first and second scroll members having first and second scroll wraps, respectively. The scroll members define a suction inlet, a discharge outlet, and fluid pockets moving therebetween. The second scroll member may include a port, and a passage. The port may be in fluid communication with at least one of the pockets. The passage may extend through a portion of the second end plate and may be in fluid communication with the port. A valve assembly may be disposed in the passage and may include a valve member displaceable between open and closed positions. A recompression volume may be disposed between the valve member and the at least one of the pockets. The recompression volume may be less than or equal to approximately one percent of a volume of one of the pockets at a suction seal-off position.

A compressor and waste heat recovery system is disclosed in which mechanical work from a prime mover along with work generated from the waste heat recovery system are used to operate the compressor. A gas producing system is heated by waste heat from operation of the compressor to produce a stream of gas used to drive a turbine. The turbine is in work communication with the compressor. In one embodiment the gas producing system is a metal hydride. An overrunning clutch can be used with the turbine. In one form multiple gas producing systems are used, one of which to emit gas while the other is used to receive and capture the emitted gas.

A fluid expander is disclosed as used in conjunction with an air compressor that is driven by a prime mover. The fluid expander is structured to extract useful work from a fluid stream and add that work to the work provided by the prime mover to the compressor. In some embodiments a clutch can be used to decouple the expander from the compressor if insufficient work is developed by the expander. A gear train can also be used to change the rotational speed prior to work being delivered to the compressor.

A compressor may include first and second scroll members having first and second scroll wraps, respectively. The scroll members define a suction inlet, a discharge outlet, and fluid pockets moving therebetween. The second scroll member may include a port, and a passage. The port may be in fluid communication with at least one of the pockets. The passage may extend through a portion of the second end plate and may be in fluid communication with the port. A valve assembly may be disposed in the passage and may include a valve member displaceable between open and closed positions. A recompression volume may be disposed between the valve member and the at least one of the pockets. The recompression volume may be less than or equal to approximately one percent of a volume of one of the pockets at a suction seal-off position.

A heat engine is configured to receive a high-pressure fluid and release a low-pressure fluid. The heat engine includes a main housing including an expansion tank and a generator housing. The heat engine includes a scroll decompressor disposed in the expansion tank. The scroll decompressor is configured to progressively decompress the high-pressure fluid to the low-pressure fluid while rotating a main shaft. The heat engine includes a generator disposed in the generator housing. The generator is driven by the main shaft. The heat engine includes a coupling disposed on the main housing configured to couple with a power receiving device. The coupling is configured to transfer rotational motion of the generator to a rotational input of the power receiving device.