DE4218299A1

DE4218299A1 - High capacity refrigeration appts. for deep-freezing, air-conditioning or building heating - uses air as working medium compressed nearly isothermally and comprises continuously working rotating machines for delivering large vol. flows, e.g. with screws for compressing refrigerant vapour

Info

Publication number: DE4218299A1
Application number: DE19924218299
Authority: DE
Inventors: Helmut Radebold
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-06-01
Filing date: 1992-06-01
Publication date: 1993-12-02

Abstract

Two such machines (1,2) are respectively mounted on a common shaft (4) as a refrigeration set, with air as a thermodynamic working medium. The first machine working as a screw compressor compresses the suction air. The heat produced during compression is given to the air to be compressed. Water is separated by a separator and drawn off partly by heating and partly by vaporisation. The isothermally compressed air after the separation of the water part, after passing through a recuperative heat exchanger (5), and with further cooling by air, enters the second screw machine. The air is expanded there at a very low temp. The separated water following the removal of the compression heat is led into an external heat exchanger in the circuit. The water is used for transporting heat and for the lubrication of the machines. USE/ADVANTAGE - Air conditioning or heating of buildings. Air at relatively low pressures can be used. Oil is no longer needed as lubricant. Wide temp. range.

Description

Schraubenverdichter, wie sie heute in einem breiten Leistungsspektrum angeboten werden, sind technologisch sehr fortgeschrittene Maschinen, die große Volumenströme fördern können. Sie werden heute in der Kühltechnik ausschließlich als Kompressoren für Kältemittel auf der Basis FCKW und ihrer Ersatzstoffe eingesetzt, um Wärme aus einem Raum tieferer Temperatur in die Umgebung zu pumpen. Sie werden mit Öl geschmiert.Screw compressors as they are today in a wide range of services offered are technologically very advanced machines, that can promote large volume flows. You will be in the today Cooling technology only as compressors for refrigerants on the CFCs and their substitutes are used to generate heat from a Pump room of lower temperature into the environment. They will with Oil lubricated.

Die vorliegende Erfindung besteht darin, Schrauben sowohl für die Verdichtung als auch für die Entspannung von Luft einzusetzen, um so große Kälteleistungen sogar in einem offenen Kreislauf zu erreichen (Fig. 1): Jeweils 2 Schrauben werden paarweise auf gleicher Welle eingesetzt, um die eine Schraube (1) wie bisher zur Kompression von Luft, die andere (2) als Entspannungsmaschine zur Entspannung des verdichteten, vorher möglichst auf Umgebungstemperatur abgekühlten Luftstromes zu verwenden. Um eine günstige Leistungszahl zu erreichen, und um gleichzeitig das bisher zur Schmierung verwendete Öl zu eliminieren, wird Wasser quasi in einem geschlossenen Kreislauf (3) verwendet, sowohl zur Schmierung der Schraube als auch zur Wärmeabfuhr aus der im Verdichterteil zu komprimierenden Luft. Der Schraubenverdichter ist wahrscheinlich eine der wenigen heutigen thermodynamischen Maschinen, der Kompression bei gleichzeitiger Kühlung zu erreichen gestattet und so zu einer isothermen Verdichtung fähig ist.The present invention consists of using screws both for the compression and for the expansion of air, in order to achieve such high cooling capacities even in an open circuit ( Fig. 1): 2 screws are used in pairs on the same shaft, around one Screw ( 1 ) as before for the compression of air, the other ( 2 ) as a relaxation machine to relax the compressed air flow, which has previously cooled to ambient temperature. In order to achieve a favorable coefficient of performance and at the same time to eliminate the oil previously used for lubrication, water is used in a closed circuit ( 3 ), both for lubricating the screw and for dissipating heat from the air to be compressed in the compressor part. The screw compressor is probably one of the few thermodynamic machines available today that allows compression to be achieved while cooling and is therefore capable of isothermal compression.

Ein solches Aggregat, das wegen der relativ geringen Drücke bei Luft als Kältemittel, und bei der Kompensation der axialen Kräfte durch die gemeinsame Welle (4) auch möglicherweise teilweise aus Kunststoffe gebaut werden kann, ist in einem weiten Temperaturbereich einsetzbar, wenn neben einem Wasserabscheider ein zusätzlicher Wärmetauscher (Rekuperator) (5) zwischen beide Maschinen eingeschaltet wird. Die restliche Feuchtigkeit fällt als Schnee aus. Auf diese Weise entsteht ein Kühlaggregat von großer Einfachheit, das keinerlei schädliche Stoffe mehr verwendet und das einen sehr breiten Einsatzbereich hat, angefangen von Tiefkühlung über Klimatisierung bis hin zu Heizung von Gebäuden.Such a unit, which due to the relatively low pressures in air as a refrigerant and in the compensation of the axial forces by the common shaft ( 4 ) may also be built partially out of plastics, can be used in a wide temperature range if a water separator is used additional heat exchanger (recuperator) ( 5 ) between both machines is switched on. The remaining moisture falls out as snow. In this way, a cooling unit of great simplicity is created that no longer uses any harmful substances and that has a very wide range of uses, from freezing to air conditioning to heating buildings.

Claims

Large capacity cooling unit with air as the working medium and almost isothermal compressions, using continuously operating, rotating machines for conveying large volume flows, such as are known, for example, equipped with screws for compressing refrigerant vapors, characterized in that two of these machines are on a common Shaft can be used as a cooling unit with air as the thermodynamic working fluid, the first machine taking over the compression of the sucked-in air while the work begins, the second machine relieving the compressed air while working, provided that the compression heat generated during the compression in the first machine via water, which is added to the air to be compressed, is discharged to the water, partly by heating it, partly by evaporating it, and the air, which is largely isothermally compressed in this way, after removal NEN of the water and after flowing through a recuperative heat exchanger with further cooling by air from the cooling room in the second machine in order to be relaxed there to very low temperatures, the separated water being circulated in an external heat exchanger after the compression heat has been removed, not takes over only the heat transport but also the lubrication of the two machines, so that oil as a lubricant can be dispensed with.