Compression of water vapour as R718 is disclosed with and without addition of additives as an aqueous solution in rotational displacement machines, i.e. refrigeration, air-conditioning and heat pump technology. To largely avoid over or under-compression, it is proposed for the easiest possible adaptation of the currently effective internal volume ratio as so-called iV value in the displacer that the compressor housing starting from the outlet side with rotor profile length L.sub.R over a length L.sub.iV comprises planar, i.e. flat iV disks (3.sub.j) with the index j for 1≤j≤n; n is the number of disks; n≥1 with a width b.sub.j per iV disk having planar surfaces P.sub.F preferably perpendicular to the neutral axis A.sub.N. The iV disks are displaced in a targeted manner individually by movement control devices (5.sub.j) per iV disk in each case by a distance s.sub.i where 0<s.sub.i≤s.sub.j.

The invention relates to a spindle compressor designed as a twin-shaft rotary displacement machine for delivering and compressing flow media, particularly steam. It comprises a pair of spindle rotors in a compressor housing (1) comprising an inlet collecting space (11) and an outlet collecting space (12). The centre distance of the pair of spindle rotors is at least 10% longer on the inlet-side end than on the outlet-side end. Each of the two spindle rotors (2, 3) is driven by an electric motor (18, 19), and an electronic synchronisation controls the electric motors (18, 19) such that the spindle rotors (2, 3) rotate in a contact-free manner.

A displacement compressor system for the refrigerant R718 includes a compressor machine, an evaporator, and a condenser. The open compressor machine is designed as a spindle compressor in the form of a double-shaft rotation displacement compressor for displacing and compressing gaseous conveying media. The displacement compressor has a spindle rotor pair which is arranged in a compressor housing and is designed with an electronic motor pair spindle rotor synchronization function. The compressor machine is arranged between the evaporator and the condenser.

The invention relates to a spindle compressor without operating fluid in the working space with a 2-tooth spindle rotor and a 3-tooth spindle rotor in a surrounding compressor housing-and preferably non-parallel rotation axes of the two spindle rotors, in particular for use in compression refrigeration machines. In order to improve the degree of efficiency while providing flexible power adjustment, it is proposed according to the invention that a multi-stage spindle compressor be used as a refrigerant compressor, whose compressor housing and whose spindle rotors are cooled via a partial-flow branch-off of liquid refrigerant from the refrigerant main flow circuit, wherein the compressor housing is cooled in a controlled manner by means of refrigerant evaporation, with the refrigerant vapor being subsequently fed to the inlet, and that, for power adjustment, there are also post-inlet feeds into the working space in addition to the inlet feed, and also pre-outlet discharges in addition to the outlet discharge from the outlet space, each with their own regulating device.

Compression of water vapour as R718 is disclosed with and without addition of additives as an aqueous solution in rotational displacement machines, i.e. refrigeration, air-conditioning and heat pump technology. To largely avoid over or under-compression, it is proposed for the easiest possible adaptation of the currently effective internal volume ratio as so-called iV value in the displacer that the compressor housing starting from the outlet side with rotor profile length L.sub.R over a length L.sub.iV comprises planar, i.e. flat iV disks (3.sub.j) with the index j for 1?j?n; n is the number of disks; n?1 with a width b.sub.j per iV disk having planar surfaces P.sub.F preferably perpendicular to the neutral axis A.sub.N. The iV disks are displaced in a targeted manner individually by movement control devices (5.sub.j) per iV disk in each case by a distance s.sub.i where 0<s.sub.i?s.sub.j.

The invention relates to a spindle compressor without operating fluid in the working space with a 2-tooth spindle rotor and a 3-tooth spindle rotor in a surrounding compressor housing-and preferably non-parallel rotation axes of the two spindle rotors, in particular for use in compression refrigeration machines. In order to improve the degree of efficiency while providing flexible power adjustment, it is proposed according to the invention that a multi-stage spindle compressor be used as a refrigerant compressor, whose compressor housing and whose spindle rotors are cooled via a partial-flow branch-off of liquid refrigerant from the refrigerant main flow circuit, wherein the compressor housing is cooled in a controlled manner by means of refrigerant evaporation, with the refrigerant vapor being subsequently fed to the inlet, and that, for power adjustment, there are also post-inlet feeds into the working space in addition to the inlet feed, and also pre-outlet discharges in addition to the outlet discharge from the outlet space, each with their own regulating device.