Abstract: A method for controlling a vapor compression system during start-up is disclosed. The rate of change, ?T1, of the temperature of refrigerant entering the evaporator, and the rate of change, ?T2, of the temperature of refrigerant leaving the evaporator are compared. Based on the comparing step, a refrigerant filling state of the evaporator is determined. The opening degree of the expansion device is then controlled according to a first control strategy in the case that it is determined that the evaporator is full or almost full, and according to a second control strategy in the case that it is determined that the evaporator is not full. Thereby it is ensured that a maximum filling degree of the evaporator is quickly reached, without risking that liquid refrigerant passes through the evaporator.

Abstract: A heat exchanger comprises a first header (1), a second header (2) spaced apart from the first header (1) by a predetermined distance, flat tubes (3) each of which defines two ends connected to the first and second headers (1, 2), respectively, to communicate the first and second headers (1, 2), fins (4) interposed between adjacent flat tubes (3), and a flow member defining a fluid-flow passage and forming a partition-wall-type heat-exchanging unit with the second header (2). A refrigeration system comprises a compressor, a condenser, a throttle device, and an evaporator that is the heat exchanger. The compressor, condenser, throttle device, and evaporator are connected sequentially, and at least part of refrigerant flowing out of an outlet of the condenser enters into the flow member to exchange heat with a refrigerant flowing out of an outlet of the evaporator.

Abstract: A method for calibrating a temperature sensor arranged in a vapor compression system is disclosed. The opening degree of an expansion device is alternatingly increased and decreased. Simultaneously a temperature of refrigerant entering the evaporator and a temperature of refrigerant leaving the evaporator are monitored. For each cycle of the opening degree of the expansion device, a maximum temperature, T1, max, of refrigerant entering the evaporator, and a minimum temperature, T2, min, of refrigerant leaving the evaporator are registered. A calibration value, ?T1, is calculated as ?T1=C?(T2, min?T1, max) for each cycle, and a maximum calibration value, among the calculated values is selected. Finally, temperature measurements performed by the first temperature sensor are adjusted by an amount defined by ?T1, max.

Abstract: A method for controlling operation of a refrigeration system (1), including one or more refrigeration entities (4), is disclosed. Each entity controller (7) obtains a measure for an error value between the measured value of a compressor control parameter and a setpoint value (8) for the compressor control parameter, and each entity controller (7) adjusts a refrigeration load of the corresponding refrigeration entity (4) to correspond to a cooling capacity of the compressor(s) (2), and in accordance with the obtained measure for an error value.

Abstract: A method of controlling a fan of a vapor compression system is disclosed. The vapor compression system includes a compressor, a heat rejecting heat exchanger, e.g. in the form of a gas cooler or a condenser, an expansion device and an evaporator arranged in a refrigerant circuit. The fan is arranged to provide a secondary fluid flow across the heat rejecting heat exchanger, e.g. in the form of an air flow. The method allows the electrical energy consumption of the fan to be reduced without risking instability of the vapor compression system.

Abstract: A magnetic valve (1) in which a valve housing (2), an armature tube (3), an inlet connection (4) and an outlet connection (5) form a single valve part is provided. An armature (9) made from a soft magnetic material is arranged movably inside the armature tube (3). A coil (16) is arranged externally to the armature tube (3) in such a manner that the armature tube (3) and the armature (9) are arranged inside the windings of the coil (16). A valve closing element (10) is connected to the armature (9) and is movable between a position in which it abuts a valve seat (8) and positions in which it does not abut the valve seat 8, thereby closing and opening the valve (1). In one embodiment, the flow path through the valve (1) from the inlet opening (6) to the outlet opening (7) does not pass through the windings of the coil (16). In another embodiment, the armature tube (3) comprises a closed end part (3a).

Abstract: A method for controlling a supply of refrigerant to an evaporator (5) of a vapor compression system (1), such as a refrigeration system, an air condition system or a heat pump, is disclosed. The vapor compression system (1) comprises an evaporator (5), a compressor (2), a condenser (3) and an expansion device (4) arranged in a refrigerant circuit. The method comprises the steps of: Actuating a component, such as an expansion valve (4), a fan or a compressor (2), of the vapor compression system (1) in such a manner that a dry zone in the evaporator (5) is changed; measuring a temperature signal representing a temperature of refrigerant leaving the evaporator (5); analyzing the measured temperature signal, e.g.

Abstract: A magnetic bearing assembly includes a lamination stack with coil apertures extending between opposing sides. A continuous unitary insulation layer is overmolded onto the opposing sides and within the coil apertures providing a coil aperture lining. The insulation layer includes a wall within the coil aperture adjoining coil aperture lining and bisecting the coil aperture into first and second openings. A coil portion is disposed in each of the first and second openings and electrically isolated from one another by the wall. The magnetic bearing assembly is arranged in a refrigerant compressor that includes an electric motor rotationally configured to rotationally drive an impeller via a shaft. A controller is in communication with the magnetic bearing and configured to energize the coils and provide a magnetic field rotationally supporting the shaft.

Abstract: A hydraulic pressure exchanger comprising a drum rotatable about an axis, a front plate arrangement having a front plate and a pressure shoe, said drum including a plurality of working cylinders, each working cylinder having a front opening and, during rotation of this drum, said front opening sliding over said pressure shoe along a path, said pressure shoe having at least two kidney-shaped openings, said kidney-shaped openings being arranged in said path. The hydraulic pressure exchanger should be operated with low noise. To this end said pressure shoe is arranged between said drum and said front plate and comprises at least one pressure cylinder arranged between two neighboring kidney-shaped openings, a piston being arranged in said pressure cylinder and resting against said front plate, said pressure cylinder being connected with a supply opening in a side of the pressure shoe opposite said front plate, said opening at least partly overlapping said path.

Abstract: An ejector arrangement (1) is provided comprising a housing (5), at least two ejectors (2) arranged in said housing (5), each ejector (2) having a motive inlet (3), a suction inlet (29), an outlet (11) and a longitudinal axis (17). Such an arrangement should have a simple construction. To this end said suction inlet (29) of said ejectors (2) are connected by means of fluid paths to a common suction line (8).

Abstract: A method for coordinating operation between at least two groups of compressors in a cooling circuit is disclosed. A first group of compressors forms part of a low temperature (LT) part of the cooling circuit and a second group of compressors forms part of a high temperature (MT) part of the cooling circuit. Each of the compressor groups comprises one or more compressors, and each of the compressor groups comprises a controller, the controllers being capable of exchanging signals. In the case that the LT compressor group needs one or more of the LT compressors to start operation, it is investigated whether or not one or more of the MT compressors is/are operating. If this is the case, one or more of the LT compressors is/are allowed to start operation. If it is not the case, the suction pressure in the MT part of the cooling circuit is established, e.g.

Abstract: A refrigerant guiding pipe having a pipe wall in which an inner chamber is formed, an opening formed in the pipe wall, and a refrigerant guiding portion. At least a part of the refrigerant guiding portion is disposed to be substantially inclined with respect to an axial direction of the refrigerant guiding pipe to guide refrigerant passing through the opening. The refrigerant guiding pipe can distribute and guide refrigerant well to help avoid non-uniform distribution of refrigerant due to layering of gaseous refrigerant and liquid refrigerant.

Abstract: A heat exchanger includes first and second headers; a plurality of tubes each defining two ends connected to the first and second headers respectively. Each tube includes a bent segment and straight segments connected to first and second ends of the bent segment respectively, the bent segment being twisted relative to the straight segments. A plurality of fins are interposed between adjacent straight segments. A length of the bent segment before bending satisfies a formula: 5t?(180??)/180+2Tw?A?30t?(180??)/180+8Tw, where: A is the length of the bent segment before bending, t is a wall thickness of the tube, Tw is a width of the tube, ? is an intersection angle between the straight segments of the tube, and ? is circumference ratio. The heat exchanger of embodiments of the present invention is easy to bend and convenient to manufacture without reducing the heat exchange efficiency.

Abstract: A flow control valve (1) for a refrigeration system is disclosed. The valve (1) comprises a valve port (14) having a substantially cylindrical inner circumference arranged to receive a protruding portion of a valve member (5). The valve member (5) comprises a protruding portion having a substantially cylindrical outer circumference corresponding to the inner circumference of the valve port (14), said protruding portion also having at least one fluted part (16), said at least one fluted part (16) defining fluid passage along the at least one fluted part (16) when the valve member (5) is in the open position. The valve member (5) is provided with at least one first fluid passage (6) extending through the valve member (5) between a second valve chamber (15) and a pressure balancing chamber (8), and at least one second fluid passage (7) establishing a fluid connection between a first valve chamber (12) and the first fluid passage (6).

Abstract: A method is provided for adjusting several parallel connected heat exchangers supplied with a coolant medium. The aim of the invention is to simplify the adjustment. For this purpose, the method consists in a) determining a specific value of heat requirement for each heat exchanger in a predetermined time period; b) comparing the specific values of all heat exchangers therebetween and c) in modifying the adjustment of the heat exchanger having the lowest specific value of heat requirement in such a way that the heat requirement thereof is increased.

Abstract: A mechanism is described for determining whether or not a ground connection is properly earthed by determining whether or not a potential difference exists between a voltage measuring point and a ground connection. A first capacitor is connected between the ground connection and a first power line and a first duplicating capacitor (having the same capacitance as the first capacitor) is connected between the voltage measuring point and the first power line. If the determining step determines that the potential difference does not exist, then it is determined that the ground connection is not properly earthed.