Abstract: A power generation system comprising a liquid pump section (4) comprising a rotary liquid pump (7) with an impeller in which a working fluid is pressurised and which is driven by a drive shaft (8); an evaporator section comprising an evaporator (9) in which the in the rotary liquid pump (7) pressurised working fluid is at least partly evaporated by addition of heat from a heat source; an expander section (3) comprising a rotary expander (11) with an inlet port (16) and a rotary expander element in which the in the evaporator section at least partly evaporated working fluid is expanded; and a generator section (5) comprising a rotary power generator (13) with a rotor, whereby the expander section (3), the liquid pump section (4) and the generator section (5) are rotably connected in such a manner that relative rotational speed ratios between the rotary expander element of the rotary expander (11), the impeller of the rotary liquid pump (7) and the rotor of the rotary power generator (13) are mechanically u

Abstract: Device for expanding a fluid, wherein the device (1) is provided with an expander element (2) for expanding the fluid, a generator (3) and a transmission (4) between the two, characterized in that the generator (3) is a liquid-cooled generator and the expander element (2) is heated using liquid, wherein the device (1) is further provided with a common liquid circuit (8) for the generator (3) and the expander element (2), wherein the liquid circuit (8) comprises a liquid pump (10) which can pump up liquid from a liquid reservoir (11), wherein the liquid circuit (8) also comprises a liquid line (9) which runs from the liquid reservoir (11) and which incorporates the liquid pump (10), the generator (3) and the expander element (2).

Abstract: A power generation system comprising a liquid pump section (4) comprising a rotary liquid pump (7) with an impeller in which a working fluid is pressurised and which is driven by a drive shaft (8); an evaporator section comprising an evaporator (9) in which the in the rotary liquid pump (7) pressurised working fluid is at least partly evaporated by addition of heat from a heat source; an expander section (3) comprising a rotary expander (11) with an inlet port (16) and a rotary expander element in which the in the evaporator section at least partly evaporated working fluid is expanded; and a generator section (5) comprising a rotary power generator (13) with a rotor, whereby the expander section (3), the liquid pump section (4) and the generator section (5) are rotably connected in such a manner that relative rotational speed ratios between the rotary expander element of the rotary expander (11), the impeller of the rotary liquid pump (7) and the rotor of the rotary power generator (13) are mechanically

Abstract: Gas expansion device for expanding a gas or a gas-liquid mixture, where the gas expansion device includes a gas expansion element with an inlet port for the gas to be expanded and an inlet pipe for the gas to be expanded. The inlet pipe is connected to the inlet port where the gas expansion device includes a first liquid injection point for the injection of liquid, where the first liquid injection point is at a position level with the inlet port or upstream from the inlet port.

Abstract: Gas expansion device for expanding a gas or a gas-liquid mixture, where the gas expansion device includes a gas expansion element with an inlet port for the gas to be expanded and an inlet pipe for the gas to be expanded. The inlet pipe is connected to the inlet port where the gas expansion device includes a first liquid injection point for the injection of liquid, where the first liquid injection point is at a position level with the inlet port or upstream from the inlet port.

Abstract: An Organic Rankine Cycle (ORC) device and method for transforming waste heat from a heat source containing compressed gas into mechanical energy. The ORC includes a closed circuit containing a two-phase working fluid, the circuit including a liquid pump for circulating the working fluid in the circuit consecutively through an evaporator which is in thermal contact with the heat source; through an expander like a turbine for transforming the thermal energy of the working fluid into mechanical energy; and through a condenser which is in thermal contact with a cooling element. The ORC determines the mechanical energy generated by the expander. A control device regulates the fraction of the working fluid entering the expander based on the determined mechanical energy such that the mechanical energy generated by the expander is maximum.

Abstract: An Organic Rankine Cycle (ORC) device and method for transforming heat from a heat source into mechanical energy. The ORC includes a closed circuit containing a two phase working fluid. The circuit comprises a liquid pump for circulating the working fluid consecutively through an evaporator which is configured to be placed in thermal contact with the heat source; through an expander for transforming the thermal energy of the working fluid into mechanical energy; and through a condenser which is in thermal contact with a cooling element. The expander is situated above the evaporator. The fluid outlet of the evaporator is connected to the fluid inlet of the expander by a raiser column which is filled with a mixture of liquid working fluid and of gaseous bubbles of the working fluid, which mixture is supplied to the expander.

Abstract: An Organic Rankine Cycle (ORC) device and method for transforming heat from a heat source into mechanical energy. The ORC includes a closed circuit containing a two phase working fluid. The circuit comprises a liquid pump for circulating the working fluid consecutively through an evaporator which is configured to be placed in thermal contact with the heat source; through an expander for transforming the thermal energy of the working fluid into mechanical energy; and through a condenser which is in thermal contact with a cooling element. The expander is situated above the evaporator. The fluid outlet of the evaporator is connected to the fluid inlet of the expander by a raiser column which is filled with a mixture of liquid working fluid and of gaseous bubbles of the working fluid, which mixture is supplied to the expander.

Abstract: An Organic Rankine Cycle (ORC) device and method for transforming waste heat from a heat source containing compressed gas into mechanical energy. The ORC includes a closed circuit containing a two-phase working fluid, the circuit including a liquid pump for circulating the working fluid in the circuit consecutively through an evaporator which is in thermal contact with the heat source; through an expander like a turbine for transforming the thermal energy of the working fluid into mechanical energy; and through a condenser which is in thermal contact with a cooling element. The ORC determines the mechanical energy generated by the expander. A control device regulates the fraction of the working fluid entering the expander based on the determined mechanical energy such that the mechanical energy generated by the expander is maximum.

Abstract: A method and apparatus for controlling the flow of a working medium through an expansion device in a closed heating system which also includes a condenser, a pump and a boiler. The expansion device is a helical screw rotor expander that has an inlet port with an inlet line connected thereto, and an outlet port. The expansion device drives an energy producing device, such as a generator. The helical screw rotor expander has an intermediate pressure port between the inlet port and the outlet port, and a branch line is connected between the intermediate pressure port and a branching point in the inlet line. A valve is in the branch line. The flow of working medium through the valve to the intermediate pressure port is controlled as a function of a state parameter.

Abstract: A helical screw rotor compressor adapted for working against a pressure container whose pressure P is allowed to vary between a lowest pressure P2 and a highest pressure P1, said compressor being driven by an electric motor. The electric motor is characterised by having in one operating range defined by the pressure interval P of said pressure container a quality such that halving of the torque of said motor will result an increase in motor speed of at least of 6 percent. It is also preferred that the compressor is optimised for an internal volume factor at which the pressure of the compressor will be lower than P2+0.85*(P1?P2) at the opening instance.

Abstract: A method and apparatus for controlling the flow of a working medium through an expansion device in a closed heating system which also includes a condenser, a pump and a boiler. The expansion device is a helical screw rotor expander that has an inlet port with an inlet line connected thereto, and an outlet port. The expansion device drives an energy producing device, such as a generator. The helical screw rotor expander has an intermediate pressure port between the inlet port and the outlet port, and a branch line is connected between the intermediate pressure port and a branching point in the inlet line. A valve is in the branch line. The flow of working medium through the valve to the intermediate pressure port is controlled as a function of a state parameter.

Abstract: A new rotor for a positive displacement compressor is provided which includes a non-rotating rotor shaft, a rotatable rotor body having end surfaces and surrounding the rotor shaft, and a mechanism for rotating the rotor body around the shaft. The rotor may be either a male rotor or a female rotor, and a positive displacement compressor is also provided which includes the new male rotor, the new female rotor, and an internal drive mechanism. Such positive displacement compressor includes radial induction bearings, and the internal drive mechanism replaces an external drive mechanism.

Abstract: The present invention relates to a compressor (1) that has an associated coolant circulation system (1, 4, 6, 8, 11, 13), and also to a method of maintaining a low bacteria content in the coolant circulating system (1, 4, 6, 8, 11, 13), in which method gas and coolant are supplied to the compressor (1) during running of the system and the gas is compressed in the compressor (1) to an outlet pressure, the gas and the coolant are removed together from the compressor (1) and then separated into a respective gas and a liquid phase, whereafter the gas is passed to a recipient and the liquid is cooled before being returned to the compressor as coolant. The method is characterized by creating bacteria-killing conditions intermittently in the system by appropriating the heat-generating capacity of the compressor (1) to raise the temperature of the circulating coolant to at least 55° C. for a duration of at least 15 seconds.

Abstract: The present invention relates to a compressor (1) that has an associated coolant circulation system (1, 4, 6, 8, 11, 13), and also to a method of maintaining a low bacteria content in the coolant circulating system (1, 4, 6, 8, 11, 13), in which method gas and coolant are supplied to the compressor (1) during running of the system and the gas is compressed in the compressor (1) to an outlet pressure, the gas and the coolant are removed together from the compressor (1) and then separated into a respective gas and a liquid phase, whereafter the gas is passed to a recipient and the liquid is cooled before being returned to the compressor as coolant. The method is characterised by creating bacteria-killing conditions intermittently in the system by appropriating the heat-generating capacity of the compressor (1) to raise the temperature of the circulating coolant to at least 55° C. for a duration of at least 15 seconds.

Abstract: A pair of co-operating screw rotors include a male rotor and a female rotor each having helically extending lobes and intermediate grooves which intermesh. The male rotor has an external radius R.sub.M and a pitch radius R.sub.MP defining a pitch circle C.sub.MP, and each lobe of the male rotor in a predetermined section has a leading lobe flank and a trailing lobe flank which are substantially convex. The predetermined section is perpendicular to an axis O.sub.M of the male rotor and an axis O.sub.F of the female rotor, and each lobe of the female rotor in the predetermined section has a leading lobe flank and a trailing lobe flank which are substantially concave. Each lobe of the male rotor and each lobe of the female rotor has an asymmetric profile in the predetermined section. Each of the leading flank and the trailing flank of at least one of the male rotor lobes has a male circular arc segment having a center of curvature A.sub.1M, A.sub.2M and a radius of curvature R.sub.1, R.sub.2.

Abstract: A refrigeration system whose refrigeration capacity can be regulated continuously in a simple and reliable manner by gradually restricting the flow of refrigerant through an economizer channel to the compressor. The refrigeration system includes a rotary screw compressor, a condenser, a first pressure reducing valve, an economizer, a second pressure reducing valve, and an evaporator connected in sequence by respective channels. An outlet channel connects the evaporator to a low pressure inlet port of the rotary screw compressor to form a closed loop for a refrigerant. An economizer channel selectively connects the economizer to a closed working chamber of the rotary screw compressor. An adjustable valve provided in the economizer channel continuously regulates a mass flow of gaseous refrigerant through the economizer channel. And a sensing device senses a value of at least one parameter of the refrigerant in the closed loop which is indicative of a required refrigeration capacity.

Abstract: The invention relates to a refrigeration system of the air cycle cooling system type, also called reversed Brayton cycle in which the air flow through compressor means (12, 16), heat exchanger means (24) for withdrawal of heat from the compressed air and finally expander means (22) from where it is delivered to perform cooling. According to the invention the system includes heat load means (41) having a large flow resistance, creating a considerable over-pressure at the expander outlet (23). A rotary screw machine is included in the expander (22) and also in the compressor means (12, 16), which latter screw rotor machine (12) is driven solely by the screw rotor machine (22) of said expander means.

Abstract: A cooled air cycle system having a compressor (1) for compressing air, heat exchangers (3,4,5) for cooling the compressed air, a water separator (6) for withdrawing water from the compressed air, and an expander (2) for expanding the air back to substantially compressor inlet pressure, which air is cooled and can be used, for example, for air-conditioning. A regenerative dryer (7) is provided in conduits between the compressor (1) and the expander (2). The dryer (7) includes a water adsorbing section (18), which alternatingly is brought into contact with the compressed air at at least two locations (A,B,C). In one location (B), which is after the first heat exchanger (3) and the water separator (6), water is adsorbed from the air by the adsorbing section (18), and in another location (A), which is before the first heat exchanger (3) and the water separator (6), the adsorbing section (18) is regenerated in that the adsorbed water is brought away by the air.