Abstract:
A method for controlling a valve arrangement (10) interconnecting at least one oil separator (8) and an oil receiver (9) in a vapour compression system (1) is disclosed. A pressure difference between a pressure prevailing inside the oil separator(s) (8) and a pressure prevailing inside the oil receiver (9) is obtained. Then a duration for an open time of an open/close sequence of the valve arrangement (10) is derived, based on the obtained pressure difference, and the valve arrangement (10) is controlled in accordance with the derived duration of an open time. The supply of oil to the oil receiver (9) can be accurately controlled, regardless of the operating conditions.
Abstract:
The present invention relates to a valve arrangement (1) comprising a valve housing (2), a valve inlet (3), a valve outlet (4) and a diaphragm assembly for controlling a fluid flow through the valve housing (2) from the valve inlet (3) to the valve outlet (4), the diaphragm assembly comprising a diaphragm (5) and a diaphragm plate (6) at least partially covering the diaphragm (5), the diaphragm (5) comprising one or more equalization holes (13) passing through the diaphragm (5) and the diaphragm plate (6) comprising one or more equalization openings (12) passing through the diaphragm plate (6), the equalization holes (13) being aligned with the equalization openings (12). According to the invention, the diaphragm assembly comprises an engagement zone engaging the diaphragm (5) in order to rotationally fix the diaphragm (5) and the diaphragm plate (6) with respect to each other. This has the effect that the equalization holes (13) will keep aligned with the equalization openings (12). Thus, proper function of the valve arrangement (1) is ensured at all times. Furthermore, the invention relates to a diaphragm assembly for a valve arrangement (1) as described above.
Abstract:
The invention relates to a capsule for a valve as well as to a valve comprising such a capsule. The task of the present invention is to provide a valve in which tight tolerances for construction can be achieved and the assembly of the valve is simplified. According to the present invention the above task is solved by a capsule (1) for a valve comprising at least one diaphragm (2), a valve seat (3), a capsule inlet (5) and a capsule outlet (6). The valve seat (3) is openable and closable to permit or stop a fluid flow from the capsule inlet (5) to the capsule outlet (6). The above task is also solved by a capsule (1) for a valve that comprises at least one diaphragm (2), a valve seat (3), a capsule inlet (5) and a capsule outlet (6), wherein the capsule (1) is structured and arranged to control the position of a pilot valve element external to the capsule (1). The above task is also solved by a valve (10) comprising a valve housing (15), wherein a capsule (1) of the above kind is arranged in the valve housing (15).
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:
An expansion valve (2) for a vapour compression system (1) and a vapour compression system (1) are disclosed. The expansion valve (1) comprises a valve element (9), a valve seat (13) as well as a biasing member (12). The valve element (9) and the valve seat (13) are arranged in a first fluid passage (6) of the expansion valve (2). The expansion valve (2) further comprises a shape memory alloy actuator (17) that exerts a force on the valve element towards an open valve position when the shape memory alloy actuator is heated by an electric current. The object of the invention is to provide an expansion valve for a vapour compression system of the above type that maybe controlled externally but is also self-regulating. To this end the shape memory alloy actuator (17) is arranged in a second fluid passage (7) of the expansion valve (2), wherein the shape memory alloy actuator (17) is arranged to be in thermal contact with the fluid in the second fluid passage (7), such that the shape memory alloy actuator also actuates the valve element (9) towards a closed valve position when the shape memory actuator (17) is cooled by the fluid in the second fluid passage (7).
Abstract:
The invention relates to a valve (1) comprising a main valve (2), a pilot valve (3), a housing (4), an inlet (5) and an outlet (8). Opening and closing of the main valve (2) is controlled by the pilot valve (3). A pilot valve seat (10) is arranged in a diaphragm (6). A pilot chamber (11) is arranged in the housing (4) separated from the inlet (5) and the outlet (8) by the diaphragm (6). Task of the invention is to provide a valve with a lower cost. According to the invention a support member (17) supports the diaphragm (6), wherein the support member (17) is guided in the housing, and wherein a radial gap (26) is arranged between the radially outer end of the diaphragm (6) and the housing (4) in a radial direction perpendicular to the opening direction of the pilot valve (3). Thereby, a cheaper, less resistant material for the diaphragm can be used.
Abstract:
The invention relates to a pilot valve arrangement (1) comprising a pilot valve device (2) which comprises a pilot valve element (13), a pilot valve seat (14) cooperating with the pilot valve element (13) and a presetting mechanism for presetting an opening pressure of the pilot valve element (13), the pilot valve arrangement (1) further comprising a presetting mechanism actuating device (3) which comprises an actuator element (17) adapted to create an actuating force in order to actuate the presetting mechanism in the pilot valve device so as to preset the opening pressure. According to the invention, the pilot valve arrangement (1) comprises a contactless force coupling arrangement adapted to transfer the actuating force from the presetting mechanism actuating device (3) to the pilot valve device (2). An inventive pilot valve device (2) is disclosed and claimed as well. The invention allows to improve maintenance and safety concerning the devices mentioned above.
Abstract:
Service of a temperature controlled valve connected to a bulb should be facilitated. To this end said bulb (5) comprises a connection geometry (10) adapted to be connected to a capillary member (6) and said casing being provided with a closed opening zone located within said connection geometry (10), said opening zone being adapted to be opened upon mounting a counterpart (15) to said connection geometry (10).
Abstract:
A method for controlling a supply of refrigerant to an evaporator (2) of a vapour compression system (1) is disclosed. During a system identification phase an opening degree (12) of the expansion valve (3) is alternatingly increased and decreased, and a maximum temperature difference, (S 4 -S 2 ) max , between temperature, S 4 , of air flowing away from the evaporator (2) and temperature, S 2 , of refrigerant leaving the evaporator (2) is determined. During normal operation, the supply of refrigerant to the evaporator (2) is controlled by calculating a reference temperature, S 2,ref , based on the monitored temperature, S 4 , and the maximum temperature difference, (S 4 -S 2 ) max , determined during the system identification phase. The supply of refrigerant to the evaporator (2) is controlled in order to obtain a temperature, S 2 , of refrigerant leaving the evaporator (2) which is substantially equal to the calculated reference temperature, S 2,ref .
Abstract:
The invention relates to a method of operating at least one distributed energy resource comprising a refrigeration system (1) with a number of cooling entities, wherein a power consumption information is communicated to a smart-grid setup (SG). According to the invention the method comprises the steps of: - requesting (S0) a power consumption information from the refrigeration system; - transmitting (S1) the power consumption information from the refrigeration system (1), wherein a total amount of power consumption (Pmin, Pmax) of the refrigeration system (1) is provided; wherein: - a cooling capacity (dQ/dt_i) of at least one cooling entity is determined wherein an entity operation condition (CE) of the cooling entity (E1, E2) is taken into account (D1); - a power consumption (W_i) of at least one cooling entity (E1, E2) is determined from the cooling capacity (dQ/dt_i) wherein a performance estimation (COP) of a refrigeration cycle for the cooling entity (E1, E2) is taken into account (D2); - providing (D3) the total amount of power consumption (Pmin, Pmax) as a sum of power consumptions (W_i) of at least the one cooling entity of the number of cooling entities (E1, E2), in particular as a sum of relevant power consumptions of the number of cooling entities (E1, E2), - receiving (S2) at the refrigeration system (1) a power reference (Wref) from the smart-grid setup (SG). The method presented enables power control of a centralized refrigeration system in a smart-grid setup where an aggregator provides the power reference. In addition, the method also enables the refrigeration system to improve determining flexibility margins beyond absolute max./min values of nominal and zero.