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 thin film sensor element (4) comprising a diaphragm (6), a first thin film electrically insulating layer (7), a thin film constraining layer (8), and a thin film sensor layer (10), said sensor layer comprising one or more sensing components, forming a layered thin film structure, where the diaphragm (6) serves as a substrate for the thin film layers (7, 8, 10). The first electrically insulating layer (7) is arranged between the diaphragm (6) and the constraining layer (8), and the constraining layer (8) is arranged between the first electrically insulating layer (7) and the sensing components (10). The first electrically insulating layer (7) is made from a material which has a Young's modulus which is significantly lower than a Young's modulus of the material of the diaphragm (6), and which is significantly lower than a Young's modulus of the material of the constraining layer (8). Thereby relaxation of strain in the first electrically insulating layer (7) is constrained, and signal drift of the sensor element (4) is minimised.
Abstract:
A method for attaching an object, such as a sight glass (3) or an electrical connector (4), to a structure, such as a valve housing (1), the object (3, 4) comprising an annular flange (6, 11). The object (3, 4) is mounted in an opening (7, 12) of the structure (1) with the annular flange (6, 11) in abutment with an annular edge (8, 13) of the opening (7, 12). The object (3, 4) is attached to the structure (1) by performing welding of the annular edge (8, 13) and the annular flange (6, 11) and displacing the welding beam along the annular flange (6, 11).
Abstract:
A method of operating a reciprocating compressor for a vapour compression system is disclosed. The reciprocating compressor comprises at least two cylinders and at least two unloaders, each unloader can be operated in an idle mode or in an active mode and therefore the reciprocating compressor can run in more than two capacity states. The capacity states alternates periodically between states in such a way that a substantially continuous range of effective capacities can be obtained while the individual cylinders are evenly loaded.
Abstract:
A method for controlling operation of a vapour compression system (1) is provided, the vapour compression system (1) comprising two or more refrigeration entities, such as display cases. A signal representing a reference power consumption is received and compared to an actual power consumption of the vapour compression system (1). Based on the comparison, local controllers (3) calculate a setpoint temperature for a corresponding refrigeration entity, in order to obtain a power consumption which is equal to the reference power consumption. Each refrigeration entity is controlled in accordance with the calculated setpoint temperatures.
Abstract:
The invention relates to an actuator for a valve in a refrigeration system. The invention also relates to a valve with such actuator, and to a refrigeration system with such valve. The actuator comprises an elongated Shape Memory Alloy (SMA) element extending along two or more string-like extensions from a distant end to a proximate end in relation to a valve element of a valve. The SMA element, when forming part of the valve, may extend from the distant end to the proximate end connected to a housing of the SMA element, however, electrically insulated from the housing. An encapsulation may provide a thermal resistance, a thermal conductor and/or an electrical resistance between the SMA element and other elements or the surroundings of the SMA element.
Abstract:
The invention relates to a thermostatic valve actuator (1 ) having set means for adjusting a set temperature, a temperature scale (5), and a reference symbol (7), said temperature scale (5) and said reference symbol (7) being movable relative to each other by a movement by said set means. Such a thermostatic valve actuator is used to control the flow of heating medium through a radiator. It should give a person in a room heated by the radiator a comfortable feeling. To this end one of said temperature scale (5) and said reference symbol (7) is adjustable with respect to said set means (3).
Abstract:
A control arrangement (1) for controlling a superheat of a vapour compression system is disclosed. The control arrangement (1) comprises a first sensor (4) and a second sensor (5) for measuring control parameters allowing a superheat value to be derived; a first controller (6) arranged to receive a signal from the first sensor (4), a second controller (10) arranged to receive a superheat value derived by a subtraction element (9), and to supply a control signal, based on the derived superheat value, and in accordance with a reference superheat value, and a summation element (8) arranged to receive input from the first controller (6) and from the second controller (10), said summation element (8) being arranged to supply a control signal for controlling opening degree of the expansion device (3) on the basis of the received input. According to a first aspect the control arrangement comprises a low pass filter (7) arranged to receive a signal from the first sensor (4) and to supply a signal to the subtraction element (9), said low pass filter (7) being designed in accordance with dynamic behaviour of the evaporator (2) and/or of the first sensor (4). According to a second aspect the first controller (6) comprises a PD element.
Abstract:
A transcritical vapour compression system (1) and a method of controlling a transcritical vapour compression system (1) are disclosed. The vapour compression system (1) is of the booster type, and comprises an external heat exchanger (19) arranged downstream relative to a refrigerant outlet of the gas cooler (3), said external heat exchanger (19) being arranged to cool refrigerant leaving the gas cooler (3) by means of heat exchange with an external heat sink, e.g. comprising energy piles (21) arranged under ground. The method comprises the step of allowing refrigerant leaving the gas cooler (3) to pass through the external heat exchanger (19), thereby cooling the refrigerant leaving the gas cooler (3) by means of heat exchange with an external heat sink. An energy efficient system is obtained which can be used in hot climate, where the ambient temperature is above the triple point of carbon dioxide (C0 2 ).
Abstract:
A dehumidifier for dehumidifying an enclosure is described. The dehumidifier has a desiccant holder for holding a desiccant and a bias mechanism to bias the dehumidifier into a first configuration in which desiccant held by the desiccant holder is exposed to an interior of the enclosure (in order to remove moisture from the enclosure). The dehumidifier also includes a translation means to overcome the bias mechanism such that, when activated, the translation means moves the dehumidifier into a second configuration in which the desiccant is exposed to an atmosphere outside the enclosure (in order to regenerate the desiccant).