Abstract: A method for controlling a vapour compression system (1) is disclosed. The vapour compression system (1) comprises an ejector (6) and a liquid separating device (10) arranged in a suction line. At least one evaporator (9) is allowed to be operated in a flooded state. A flow rate of refrigerant from the liquid separating device (10) to the secondary inlet (15) of the ejector (6) is detected, and it is determined whether or not the flow rate is sufficient to remove liquid refrigerant produced by the evaporator(s) (9) being allowed to be operated in a flooded state from the liquid separating device (10).

Abstract: A method for controlling a vapour compression system (1) comprising an ejector (6) is disclosed. In the case that a pressure difference between a pressure prevailing in the receiver (7) and a pressure of refrigerant leaving the evaporator (9) decreases below a first lower threshold value, the pressure of refrigerant leaving the heat rejecting heat exchanger (5) is kept at a level which is slightly higher than the pressure level providing optimal COP. Thereby the ejector (6) can operate at lower ambient temperatures, and the energy efficiency of the vapour compression system (1) is improved.

Abstract: A method for controlling a vapour compression system (1) is disclosed, the vapour compression system (1) comprising at least one expansion device (8) and at least one evaporator (9). For each expansion device (8), an opening degree of the expansion device (8) is obtained, and a representative opening degree, ODrep, is identified based on the obtained opening degree(s) of the expansion device(s) (8). The representative opening degree could be a maximum opening degree, ODmax, being the largest among the obtained opening degrees. The representative opening degree, ODrep, is compared to a predefined target opening degree, ODtarget, and a minimum setpoint value, SPrec, for a pressure prevailing inside a receiver (7), is calculated or adjusted, based on the comparison. The vapour compression system (1) is controlled to obtain a pressure inside the receiver (7) which is equal to or higher than the calculated or adjusted minimum setpoint value, SPrec.

Abstract: A vapour compression system (1) comprising at least two evaporator groups (5a, 5b, 5c), each evaporator group (5a, 5b, 5c) comprising an ejector unit (7a, 7b, 7c), at least one evaporator (9a, 9b, 9c) and a flow control device (8a, 8b, 8c) controlling a flow of refrigerant to the at least one evaporator (9a, 9b, 9c). For each evaporator group (5a, 5b, 5c) the outlet of the evaporator (9a, 9b, 9c) is connected to a secondary inlet (12a, 12b, 12c) of the corresponding ejector unit (7a, 7b, 7c). The vapour compression system (1) can be controlled in an energy efficient and stable manner. A method for controlling the vapour compression system (1) is also disclosed.

Abstract: The invention relates to a method for configuring, on a control unit, operating parameters of a plurality of devices of a refrigeration system. A user selects on the control unit, among the plurality of devices of the refrigeration system, a first device to configure. Information of valid configurable operating parameters of the first device is provided on the control unit. The user selects at least one of the valid configurable operating parameters of the first device, thereby configuring the first device. Information stored about operating parameters of other devices of the refrigeration system, based on the configuration of the first device, is then provided on the control unit. Finally, the user confirms, on the control unit, one or more operating parameters of one or more of the other devices, thereby configuring the one or more other devices. The invention also relates to a control unit and a refrigeration system.

Abstract: A method for monitoring gas pressure in a heat rejecting heat exchanger in a cooling circuit is disclosed. The present capacity of one or more compressors in the cooling circuit compared to a maximum capacity of the one or more compressors is established. If the present capacity of the one or more compressors is at least at a level corresponding to a pre-set percentage of the maximum capacity, a period of time elapsed from a point in time where the compressor capacity reached said level is established. If the established period of time has a duration which is longer than a pre-set period of time, then it is concluding that the cooling medium is in a gas loop operational mode, allowing an operator or a controller to adjust operation of the cooling plant such that the cooling medium is brought out of the gas loop operational mode.

Abstract: The invention relates to a method for configuring, on a control unit, operating parameters of a plurality of devices of a refrigeration system. A user selects on the control unit, among the plurality of devices of the refrigeration system, a first device to configure. Information of valid configurable operating parameters of the first device is provided on the control unit. The user selects at least one of the valid configurable operating parameters of the first device, thereby configuring the first device. Information stored about operating parameters of other devices of the refrigeration system, based on the configuration of the first device, is then provided on the control unit. Finally, the user confirms, on the control unit, one or more operating parameters of one or more of the other devices, thereby configuring the one or more other devices. The invention also relates to a control unit and a refrigeration system.

Abstract: A method for controlling a valve arrangement (12), e.g. in the form of a three way valve, in a vapour compression system (1) is disclosed, the vapour compression system (1) comprising an ejector (6). The valve arrangement (12) is arranged to supply refrigerant to a compressor unit (2) from the gaseous outlet (11) of a receiver (7) and/or from the outlet of an evaporator (9). The vapour compression system (1) may be operated in a first mode of operation (summer mode) or in a second mode of operation (winter mode). When operated in the second mode of operation, it is determined whether or not conditions for operating the vapour compression system (1) in the first mode of operation are prevailing. If this is the case, the valve arrangement (12) is actively switched to the first mode of operation by closing a first inlet (13) towards the evaporator (7) and fully opening a second inlet (14) towards the receiver (7).

Abstract: A method for controlling a vapour compression system (1), the vapour compression system (1) comprising a compressor unit (2) comprising one or more compressors (10, 11, 13), is disclosed. At least one of the compressors (11, 13) of the compressor unit (2) is connectable to a gaseous outlet (9) of a receiver (5), and at least one of the compressors (10, 13) of the compressor unit (2) is connectable to an outlet of an evaporator (7). A parameter of the vapour compression system (1) is measured, an enthalpy of refrigerant leaving the heat rejecting heat exchanger (3) being derivable from the measured parameter. A setpoint value for a pressure inside the receiver (5) is calculated, based on the measured parameter, and the compressor unit (2) is operated in accordance with the calculated setpoint value, and in order to obtain a pressure inside the receiver (5) which is equal to the calculated setpoint value.

Abstract: A method for controlling a vapour compression system (1) is disclosed, the vapour compression system (1) comprising an ejector (5). The method comprises controlling a compressor unit (2) in order to adjust a pressure inside a receiver (6), on the basis of a detected pressure of refrigerant leaving an evaporator (8). The portion of refrigerant leaving the evaporator (8) which is supplied to a secondary inlet (15) of the ejector is maximised and the portion of refrigerant supplied directly to the compressor unit (2) is minimised, while ensuring that the pressure of refrigerant leaving the evaporator (8) does not decrease below an acceptable level.

Abstract: A method for controlling a variable capacity ejector unit (7) arranged in a refrigeration system (1) is disclosed. An ejector control signal for the ejector unit (7) is generated, based on an obtained temperature and an obtained pressure of refrigerant leaving a heat rejecting heat exchanger (3), or on the basis of a high pressure valve control signal for controlling an opening degree of a high pressure valve (6) arranged fluidly in parallel with the ejector unit (7). The ejector control signal indicates whether the capacity of the ejector unit (7) should be increased, decreased or maintained. The capacity of the ejector unit (7) is controlled in accordance with the generated ejector control signal. The power consumption of the refrigeration system (1) is reduced, while the pressure of the refrigerant leaving the heat rejecting heat exchanger (3) is maintained at an acceptable level.

Abstract: The invention relates to a method for configuring, on a control unit, operating parameters of a plurality of devices of a refrigeration system. A user selects on the control unit, among the plurality of devices of the refrigeration system, a first device to configure. Information of valid configurable operating parameters of the first device is provided on the control unit. The user selects at least one of the valid configurable operating parameters of the first device, thereby configuring the first device. Information stored about operating parameters of other devices of the refrigeration system, based on the configuration of the first device, is then provided on the control unit. Finally, the user confirms, on the control unit, one or more operating parameters of one or more of the other devices, thereby configuring the one or more other devices. The invention also relates to a control unit and a refrigeration system.

Abstract: A method for monitoring gas pressure in a heat rejecting heat exchanger in a cooling circuit is disclosed. In the heat rejecting heat exchanger, pressure is controlled by means of a control unit, said control unit controlling at least one valve. The present capacity of one or more compressors in the cooling circuit compared to a maximum capacity of the one or more compressors is established. The maximum capacity may be the rated capacity of the compressors, or it may be a maximum capacity under the given circumstances and/or the given operating conditions. If the present capacity of the one or more compressors is at least at a level corresponding to a pre-set percentage of the maximum capacity, a period of time elapsed from a point in time where the compressor capacity reached said level is established. If the established period of time has a duration which is longer than a pre-set period of time, then it is concluding that the cooling medium is in a gas loop operational mode.