Abstract: A screw compressor includes a casing, a screw, an air entry, an air outlet, a slide valve with a flexible volume ratio, and first and second air cylinders. The slide valve is disposed between the first and second air cylinders and includes a slide valve main body. Two ends of the slide valve seal the first and second air cylinders. The first air cylinder is connected to the air outlet of the compressor through a first connection pipe, and the second air cylinder is connected to a last closed spiral flute through a second connection pipe. The slide valve searches for balance under the driving of pressures in the first and second air cylinders. The screw compressor having a slide valve with a flexible volume ratio can enable the volume ratio of the compressor to be automatically adjusted to an optimal state.

Abstract: A double-screw liquid pump is provided, which is applicable to an Organic Rankin Cycle (ORC). The double-screw liquid pump includes a semi-sealed or fully sealed shell, and the shell includes a first cavity and a second cavity isolated from each other. A motor is disposed in the first cavity, and a main body part of a double-screw is disposed in the second cavity. At least one rotor of the double-screw is fixedly connected to a rotor of the motor, and the double-screw rotates through driving of the motor. A liquid refrigerant injection inlet and a refrigerant outlet are disposed on the first cavity, and the motor is cooled through evaporation of a liquid refrigerant; a liquid inlet and a liquid outlet are disposed on the second cavity.

Abstract: A screw expansion power generation device is disclosed, applicable to an Organic Rankin Cycle (ORC). The power generation device includes a semi-sealed or fully sealed shell. The shell includes an expander cavity and a generator cavity. The expander cavity is not in communication with the generator cavity. A screw expander is disposed in the expander cavity, and a generator is disposed in the generator cavity. A rotor of the screw expander is fixedly connected to a rotor of the generator. The power generation device drives the generator to generate power through rotation of the rotor of the screw expander. A liquid refrigerant injection inlet and a refrigerant outlet are disposed on the generator cavity. The generator is cooled through evaporation of a liquid refrigerant. The screw expansion power generation device of the present invention is semi-sealed or fully sealed. The screw expander and the generator are disposed in the shell as a whole.

Abstract: A liquid pump of a screw expander is disclosed, applicable to an Organic Rankin Cycle (ORC). The liquid pump of a screw expander includes a semi-sealed or fully sealed shell. An expander unit and a liquid pump unit are disposed in the shell. The expander unit includes a screw rotor, and the liquid pump unit includes a screw rotor. The rotor of the expander unit is fixedly connected to the rotor of the liquid pump unit. The rotor of the liquid pump unit rotates under driving of the rotor of the expander unit. In the liquid pump of a screw expander applied to the ORC, since a resistance torque of the female rotor is small, the liquid pump does not wear even when the liquid viscosity is low, contributing to high reliability of the liquid pump. Meanwhile, the liquid pump is driven by the screw expander, thereby further improving power generation efficiency of the ORC.

Abstract: A screw compressor for connecting with an economizer for gas supply, includes a main body defining a compressor cavity, a male rotor and a female rotor received in the compressor cavity, a gas-vent base defining at least one gas-supply hole therein adapted for communicating with the economizer. The male rotor and the female rotor are parallel to and meshed with each other. At least the male rotor includes at least two teeth defining at least one tooth channel therebetween. The gas-supply hole is axially aligned with the at least one tooth channel to let gas from the economizer pass therethrough and enter into the at least one tooth channel along the axial direction of the male rotor.