EP4325142A1 - Auswerfer, der einen betätigungsmechanismus mit einem vorsteuerventil und einem ausgleichskanal zwischen zylinderkammern aufweist - Google Patents

Auswerfer, der einen betätigungsmechanismus mit einem vorsteuerventil und einem ausgleichskanal zwischen zylinderkammern aufweist Download PDF

Info

Publication number
EP4325142A1
EP4325142A1 EP22190394.1A EP22190394A EP4325142A1 EP 4325142 A1 EP4325142 A1 EP 4325142A1 EP 22190394 A EP22190394 A EP 22190394A EP 4325142 A1 EP4325142 A1 EP 4325142A1
Authority
EP
European Patent Office
Prior art keywords
needle
ejector
nozzle
inlet
cylinder chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22190394.1A
Other languages
English (en)
French (fr)
Inventor
Michael Birkelund
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Danfoss AS
Original Assignee
Danfoss AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Danfoss AS filed Critical Danfoss AS
Priority to EP22190394.1A priority Critical patent/EP4325142A1/de
Priority to PCT/EP2023/072386 priority patent/WO2024038014A1/en
Publication of EP4325142A1 publication Critical patent/EP4325142A1/de
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2341/00—Details of ejectors not being used as compression device; Details of flow restrictors or expansion valves
    • F25B2341/001—Ejectors not being used as compression device
    • F25B2341/0013—Ejector control arrangements

Definitions

  • the present invention relates to an ejector, e.g. for a refrigeration circuit with circulated refrigerant, with a primary (fluid) inlet, a secondary (fluid) inlet, a (fluid) outlet, a nozzle, and a mixing portion for mixing fluid supplied with a high pressure at the primary inlet and fluid sucked from the secondary inlet.
  • the invention further relates to an ejector assembly with at least two ejectors.
  • fluid is supplied by the refrigeration circuit with the high pressure to the primary inlet.
  • the refrigeration circuit supplies fluid to the secondary inlet with a secondary pressure that is less than the high pressure.
  • the nozzle jets the fluid received at the primary inlet into the mixing portion. Thereby, a flow velocity is increased. Fluid received at the secondary inlet is additionally sucked into the mixing portion. As a result, the fluid received at the primary inlet mixes with the fluid received at the secondary inlet in the mixing portion. Thereafter, the combined fluid flow leaves the ejector through the outlet.
  • a diffuser is arranged between the mixing portion and the outlet. In some applications, a flow of fluid through the nozzle can be prevented. By this, the ejector is closed.
  • ejectors are known from WO 2018/159320 A1 , US 7,841,193 B2 , JP 4 134 918 B2 , and EP 1 923 575 A2 .
  • Fast opening or closing of an ejector can cause fast pressure variations in the refrigeration circuit employing the ejector, e.g. pressure peaks. This can lead to damages of components of the refrigeration circuit. Furthermore, this can lead to instability in the controlling of the refrigeration system.
  • stepper motors are particularly expensive and not perfectly suitable for all applications.
  • an ejector e.g. for a refrigeration circuit with circulated refrigerant, according to claim 1.
  • the ejector comprises:
  • the present invention ensures smooth opening and closing of the ejector. Pressure peaks due to fast opening and/or closing are reliably avoided.
  • the implementation is cost-effective. For example, no expensive stepper motor is needed in order to ensure smooth opening and closing.
  • the risk is reduced that the needle moves with excessive speed and/or flutters due to external pressure fluctuations, e.g. to fluctuations of a primary pressure applied to the primary inlet by an external refrigeration circuit.
  • Fluid from the primary inlet can enter the first cylinder chamber via the chamber inlet. This allows filling up the first cylinder chamber while the (volume of) the first cylinder chamber increases.
  • the drain passage is configured for discharging fluid from the second cylinder chamber when the pilot valve is open. This allows decreasing the (volume of) the second cylinder chamber (by displacement of the piston in the cylinder).
  • the equalization passage allows that fluid flows from the first cylinder chamber to the second cylinder chamber.
  • the pilot valve is closed.
  • no fluid is discharged from the second cylinder chamber.
  • the piston is displaced in order to maximize (the volume of) the second cylinder chamber.
  • the second cylinder chamber is filled up by the fluid from the first cylinder chamber entering the second cylinder chamber through the equalization passage while the (volume of) the second cylinder chamber increases. At the same time, the (volume) of the first cylinder chamber is decreased.
  • the drain passage is blocked (closed) when the solenoid valve is in a closed state.
  • the chamber inlet, the equalization passage, and the drain passage may be completely integrated in the ejector. They are not constituted by fluid connections provided by an environment or any outer element. In particular, they are not constituted by any fluid connections of a refrigeration circuit employing the ejector that are not part of the ejector as such.
  • the actuating mechanism is for moving the needle along a longitudinal direction between the opened position and the closed position.
  • the cylinder may extend parallel to the longitudinal axis and the piston may be configured to reciprocate parallel to the longitudinal axis in the cylinder for either maximizing (the volume of) the first cylinder chamber (such that the needle is in the opened position) or maximizing (the volume of) the second cylinder chamber (such that the needle is in the closed position).
  • the longitudinal direction may be parallel to a central axis.
  • the cylinder, the piston, the needle, the needle seat, the nozzle, and/or the mixing portion may extend at least substantially along the central axis.
  • a diffuser portion may be formed downstream of the mixing portion.
  • the diffuser portion may extend along the central axis.
  • the (whole) ejector extends substantially along the central axis.
  • a piston area is a cross-section area of the piston.
  • the piston area may be defined within a plane perpendicular to the longitudinal direction.
  • the piston area is at least 1000 times a flow cross-section of the equalization passage. Especially, the piston area may be at least 1600 times the flow cross-section of the equalization passage.
  • the flow cross-section of the equalization passage limits, by its flow resistance, a flow rate (e.g. measured in ml/s) between the first cylinder chamber to the second cylinder chamber.
  • the total volume change of the second cylinder chamber during opening increases with increasing piston diameter.
  • a closing time is extended.
  • the piston's velocity during opening is slower.
  • the piston's velocity reaches a substantially constant value shortly after transition from the opened position to the closed position has started. This value may be related to the flow rate divided by the piston area.
  • the piston area may be at least 1200 times a flow cross-section of the drain passage, especially at least 1920 times.
  • the flow cross-section of the drain passage limits a fluid discharge rate (e.g. measured in ml/s), with which fluid can be discharged from the second cylinder chamber via the drain passage when the pilot valve is open.
  • a net flow rate for the second cylinder chamber may be (at least substantially) determined by the fluid discharge rate and the flow rate of fluid entering through the equalization passage.
  • the piston's velocity may reach a substantially constant value shortly after transition from the closed position to the second position has started. This value may be related to the net flow rate divided by the piston area. If the piston area and hence the total volume change of the second cylinder chamber required for opening are increased, the opening time is extended.
  • piston area increases with respect to the flow cross-section of the equalization passage while the flow cross-section of the drain passage remains the same.
  • piston area increases with respect to the equalization passage as well.
  • a needle seat area which is a cross-section area of the needle seat where the needle engages the needle seat in the closed position, is in the range from 1,005 to 1,4 times a flow cross-section of the nozzle.
  • the cross-section area of the needle seat is particularly small. Accordingly, the effects of pressure changes at a needle tip when then the needle is arriving at the needle seat and starting to lift off from the needle seat are minimized. This facilitates smooth and controlled opening and closing of the ejector.
  • the ejector may comprise a housing. This ensures protection of the components inside the housing.
  • the housing may include a main sleeve. An interior of the main sleeve may extend along the central axis.
  • the housing may further include a top cover.
  • the top cover can be fixed to an end of the main sleeve in the longitudinal direction at a side opposite to the outlet.
  • the top cover may be removably fixed to the main sleeve. This facilitates maintenance.
  • the pilot valve is a solenoid valve.
  • Solenoid valves are particularly inexpensive, reliable, and easy to control. It is not necessary to control an exact opening degree of the pilot valve.
  • the present invention ensures smooth opening and closing also in the case that the pilot valve can be switched only between an open state and a closed state. No additional intermediate states of the pilot valve are needed in order to keep the movement speed of the needle below a pre-determined threshold.
  • the piston area corresponds to at least 20 times the needle seat area.
  • a stroke of the needle between the closed position and the opened position correspond to at least 2*(A noz / ⁇ ) 0,5 , where A noz is the flow cross-section of the nozzle.
  • the ejector comprises a check valve function for preventing fluid flow from the outlet to the secondary inlet.
  • the first cylinder chamber may be a piston-rod side cylinder chamber.
  • the second cylinder chamber me be the cylinder chamber in the same cylinder at the other side of the piston.
  • the needle may be formed integrally with the piston.
  • the needle may be a piston rod at the same time. This is a particularly reliable, cost-effective, and lightweight implementation. It may include at least one hole extending thorough the piston.
  • the equalization passage is formed (completely) in the piston. This allows fast and cost-efficient production.
  • the flow cross-section of the equalization passage may be in the range from 1,2 to 2,5 times the flow cross-section of the drain passage when the pilot valve is in its open state. This ensure that a flow resistance of the drain passage is higher than a flow resistance of the equalization passage. Only a slight pressure drop from the first cylinder chamber to the second cylinder portion occurs even during the needle's transition from the closed position to the opened position. The movement velocity of the piston and the needle can be precisely controlled and kept low. This further facilitates smooth opening of the ejector.
  • the flow cross-section of the drain passage can be determined by the flow cross-section of the pilot valve.
  • the pilot valve can be designed to be as small as possible. This reduces the costs. Accordingly, the flow cross-section of the equalization passage may be in the range from 1,2 to 2,5 times a flow cross-section of the pilot valve when the pilot valve is in its open state.
  • a flow cross-section of the chamber inlet is larger than the flow cross-section of the equalization passage.
  • the flow cross-section of the chamber inlet may be at least 5 times, especially at least 10 times, the flow cross-section of the equalization passage.
  • the needle seat is at least axially fixed with respect to the housing. This facilitates precise opening and closing of the ejector.
  • the nozzle may be arranged in an interior of the housing. It may be at least axially fixed with respect to the housing.
  • the nozzle may comprise a throat portion and a divergent nozzle portion.
  • the throat portion may define the flow cross-section of the nozzle.
  • the divergent nozzle portion may be arranged downstream of the throat portion. It may be of a conical shape, wherein an inner diameter increases towards a downstream end of the nozzle. The downstream end of the nozzle may protrude towards the mixing portion.
  • a nozzle inlet is formed directly upstream of the nozzle, wherein the nozzle inlet tapers toward the nozzle, wherein the needle seat is located in the nozzle inlet, and wherein a length of the nozzle inlet may correspond to at least 1,8 times the stroke of the needle between the closed position and the opened position.
  • the nozzle inlet and the nozzle can be formed in a one-piece component, e.g. in a nozzle insert.
  • the nozzle insert may be mounted to an insert assembly holder that is mounted in the housing, e.g. in an interior of the main sleeve.
  • the nozzle insert may be fixed to the housing. However, it may be removably fixed to the housing in order to facilitate maintenance.
  • the ejector can comprise a resilient member acting against minimizing (the volume of) the second cylinder chamber by the piston.
  • the resilient member urges the piston towards maximizing (the volume of) the second cylinder chamber.
  • the resilient member may urge the needle towards its closed position.
  • the resilient member may engage directly with the piston and/or directly with the needle.
  • the resilient member may be provided between an end wall of the cylinder at the side of the second cylinder chamber and the piston. The resilient member facilitates the transition of the needle from its opened position to its closed position.
  • the resilient member may include a coil spring.
  • the ejector is configured such that the opening time of the needle is at least 0,5 s, e.g. at least 1 s.
  • the long opening time prevents fast pressure variations and hence reduces a risk of damages in a refrigeration circuit employing the ejector.
  • the ejector is configured such that the closing time of the needle is at least 1 s, e.g. at least 2 s.
  • the long closing time prevents fast pressure variations and hence reduces a risk of damages in a refrigeration circuit employing the ejector.
  • the ejector is configured such that the needle moves, during the transition from its closed position to its opened position (in normal operation), with a substantially constant velocity over a displacement length corresponding to at least 70 % of the stroke. This ensures controlled and smooth opening and reduces the risk of damages in any refrigeration circuit employing the ejector.
  • the ejector is configured such that the needle moves, during the transition from its opened position to its closed position (in normal operation), with a substantially constant velocity over a displacement length corresponding to at least 70 % of the stroke. This ensures controlled and smooth closing and reduces the risk of damages in any refrigeration circuit employing the ejector.
  • Substantially constant velocity may mean that the velocity changes by 15 % at the maximum during the respective movement phase.
  • the flow cross-section of the nozzle is at least 50 mm 2 .
  • the ejector exhibits a high capacity.
  • the cylinder is formed by a cylinder insert and the top cover.
  • the cylinder insert may be inserted in an interior of the main sleeve.
  • the cylinder insert may be removably mounted in the main sleeve. This facilitates maintenance.
  • the ejector may comprise an elastic member, for example a spring, especially a coil spring.
  • the elastic member may bias the cylinder insert against the top cover.
  • the second cylinder chamber may be arranged at the side of the top cover. This ensures proper sealing between those elements. This ensures that the pressure propagation to the second cylinder chamber is determined by the pressure propagation from the first cylinder chamber to the second cylinder chamber via the equalization passage. A risk of substantial leakage and pressure propagation from the primary inlet to the second cylinder chamber that bypasses the equalization passage is reduced.
  • An annular end face of the cylinder insert for abutting on the top cover may be ground flat.
  • the elastic member may be squeezed between the cylinder insert and a member that is at least axially fixed with respect to the housing.
  • the elastic member may be squeezed between the cylinder insert and the insert assembly holder.
  • the ejector comprises a filter between the primary fluid inlet and the needle seat.
  • the filter may be arranged circumferentially about the needle and the needle seat. It may be supported by the elastic member.
  • the needle is made of a first material and the needle seat is made of a second material, wherein a hardness of the second material is higher than a hardness of the first material.
  • the hardness of the second material may correspond to at least 1,4 times the hardness of the second material.
  • the nozzle insert (which includes the needle seat) is made of the second material.
  • an ejector assembly comprising at least two ejectors according to any one of the described embodiments and modifications.
  • the ejectors may be arranged in parallel.
  • a flow cross-section of a second one of the at least two ejectors is different from a flow cross-section of a first one of the at least two ejectors.
  • the flow cross-section of the second one can be at least 1,2 times the flow cross-section of the first one.
  • a flow cross-section of an element (like a passage, a channel, or the like, e.g. the nozzle), this may mean a minimum cross-section of the respective element along an intended flow direction through the element.
  • FIG. 1 An embodiment of an ejector 1 according to the present invention is shown in Fig. 1 .
  • the ejector 1 comprises a primary (fluid) inlet 2, a secondary (fluid) inlet 7, and an (fluid) outlet 12.
  • the primary inlet 2 may be also referred to as high pressure inlet 2.
  • the ejector 1 extends along a central axis C.
  • a longitudinal direction L is parallel to the central axis C.
  • fluid can flow from the first inlet 2 through a nozzle 5, a mixing portion (which includes a convergent mixing portion 6 and a cylindrical mixing portion 10), and a diffuser portion 11 to the fluid outlet 12.
  • fluid is drawn from the secondary inlet 7 into the mixing portion 6.
  • the fluid drawn from the secondary inlet 7 joins the fluid from the primary inlet 2 in the convergent mixing portion 6. This results in mixing of the fluid from the primary inlet 2 and the fluid drawn from the secondary inlet 7 in the convergent mixing portion 6 and the cylindrical mixing portion 10 that follows downstream of the convergent mixing portion 6.
  • the ejector 1 includes a needle valve mechanism with a needle 20 and a needle seat 26.
  • the needle 20 If the needle 20 is in a closed position (not shown), it abuts the needle seat 26 and blocks the fluid connection between the primary inlet 1 and the nozzle 5. This prevents that fluid from the primary inlet 1 can enter into the nozzle 5 and flow further into the convergent mixing portion 6. This corresponds to a closed state of ejector 1.
  • the needle 20 is lifted from the needle seat 26 by a needle stroke S (see Fig. 4 ). This allows fluid flow from the primary inlet 2 into the nozzle 5.
  • the stroke S is the displacement of the needle 20 along the longitudinal direction L between its opened position and its closed position.
  • the stroke S may be at least 10 mm, for example in the range from 12 mm to 30 mm.
  • a housing 70 of the ejector 1 includes a main sleeve 71, an upstream-side top cover 76, a first diffuser tube 74, and a second diffuser tube 75.
  • the first diffuser tube 74 and the second diffuser tube 75 form at least a downstream part of the diffuser portion 11.
  • the housing 70 further includes a primary (fluid) inlet connector 72, which is fixed to the main sleeve 71 and forms the primary inlet 2, and a secondary (fluid) inlet connector 73, which is fixed to the main sleeve 71 and forms the secondary inlet 7.
  • the ejector 1 further comprises an actuating mechanism 30 for moving the needle 20 along the longitudinal direction L between the opened position and the closed position.
  • the actuating mechanism 30 comprises a pilot valve 50 and a piston 31.
  • the piston 31 is arranged in a cylinder 35 and can be axially displaced within the cylinder 35 (i.e. along the central axis C).
  • the needle 20 is mechanically connected to the piston 31 such that the axial movement of the piston 31 in the cylinder 35 is transferred to movement of the needle 20 along the longitudinal direction L. Accordingly, the needle 20 can be moved from its opened position to its closed position and vice versa by corresponding axial movements of the piston 31.
  • the needle 20, the piston 31, and the cylinder 35 are all arranged coaxially along the central axis C and the needle 20 is at least axially fixed to the piston 31.
  • the needle 20 and the piston 31 can be formed integrally (in one piece) as shown in Figs. 1 to 3 .
  • the needle 20 (in particular a needle stem 25) also constitutes a piston rod for the piston 31.
  • the cylinder 35 can be formed by a cylinder insert 77 and the top cover 76 as shown in Figs. 1 to 3 .
  • the cylinder insert 77 is arranged in an interior of the main sleeve 71 and directly abuts the top cover 76.
  • the cylinder insert 77 guides the piston 31 and its piston rod (which is the needle 20 in this embodiment).
  • the piston 31 is configured to form a first cylinder chamber 37 and a second cylinder chamber 38 within the cylinder 35. It can divide an interior of the cylinder 35 into the first cylinder chamber 37 and the second cylinder chamber 38 (along the longitudinal direction L).
  • a volume of the first cylinder chamber 37 is maximized (maximal) when the needle 20 is in its opened position. It is minimized when the needle 20 is in its closed position. It may decrease (at least substantially) to a minimum volume (small residual volume) when the needle 20 is in its closed position (not shown, corresponds to a lowermost possible position of the piston 31 in Figs. 1 to 3 ).
  • a volume of the second cylinder chamber 38 is maximized (maximal) if the needle 20 is in its closed position. It is minimized when the needle 20 is in its opened position (correspond to an uppermost possible position of the piston 31 as shown in Figs. 1 to 3 ). It may decrease (at least substantially) to zero when the needle 20 is in its opened position.
  • an annular end wall 40 which is provided on a surface of the piston 31 facing the second cylinder chamber 38, causes that a residual volume of the second cylinder chamber 38 remains even if the needle 20 is in its opened position. This ensures that the equalization passage 32 is not closed when the needle 20 is in the opened position.
  • a primary (fluid) inlet chamber 3 is formed at a side of the cylinder insert 77 in the longitudinal direction L that faces away from the top cover 76.
  • the primary inlet connector 72 opens into the primary inlet chamber 3.
  • the first cylinder chamber 37 is in fluid communication with the primary inlet 2 via a chamber inlet 36.
  • the chamber inlet 36 is a fluid connection provided between the primary inlet chamber 3 and an end of the cylinder 35 in the longitudinal direction L at the side of the needle 20 (an end of the cylinder 35 at the side of the first cylinder chamber 37, i.e. a lower end of the cylinder 35 in Figs. 1 to 3 ).
  • the chamber inlet 36 may be formed in the cylinder insert 77, for example as at least one bore extending along the longitudinal direction L. In the embodiment shown in Figs. 1 and 2 , four or six of such bores are formed in the cylinder insert 77. Two of them can be seen in Figs. 1 and 2 .
  • the other end of the cylinder 35 in the longitudinal direction L is in fluid communication with the secondary inlet 7 via a drain passage.
  • the pilot valve 50 is arranged in the drain passage. When the pilot valve 50 is in its closed state, it blocks (closes) the drain passage. When the pilot valve 50 is in its open state, the drain passage is open and the second cylinder chamber 38 is in fluid communication with the secondary inlet 7.
  • the drain passage is formed between the second cylinder chamber 38 on the one hand and, on the other hand, the secondary inlet 7 and/or a space that is in (direct) fluid communication with the secondary inlet 7.
  • the drain passage is formed between the second cylinder chamber 38 and a secondary (fluid) inlet chamber 8, which is in direct fluid communication with the secondary inlet 7.
  • the second cylinder chamber 38 is in fluid communication with the outlet 12 via the drain passage when the pilot valve 50 is in an open state.
  • the drain passage with the solenoid valve 50 is formed between the second cylinder chamber 38 and the fluid outlet 12 and/or a space that is in fluid communication with the fluid outlet 12 in this case.
  • a blocking means e.g. a check valve, can be employed to prevent fluid flow from the secondary inlet 7 to the fluid outlet 12 via the drain passage.
  • the drain passage may be formed completely within the ejector 1. It is integrated in the ejector 1 as such.
  • the drain passage includes a fluid connection 39 between the upper end of the cylinder 35 (the second cylinder chamber 38) and an upstream side of the pilot valve 50.
  • Said fluid connection 39 may be also referred to as the chamber outlet 39.
  • the chamber outlet 39 may be formed by at least one channel, for example two channels, within the top cover 76.
  • the drain passage includes a first fluid passage 54 formed in the top cover 76, a second fluid passage 55 that is also formed in the top cover 76, a fluid passage 56 formed in the main sleeve 71, and a fluid passage 57 formed between the main sleeve 71 and an insert assembly holder 78.
  • the fluid passage 57 is a substantially annular gap between the main sleeve 71 and the insert assembly holder 78.
  • the drain passage opens into the secondary inlet chamber 8.
  • the secondary inlet connector 73 also opens into the secondary inlet chamber 8. Hence, the downstream side of the pilot valve 50 is in fluid communication with the secondary inlet 7, and the second cylinder chamber 38 is in fluid communication with the secondary inlet 7 when the pilot valve 50 is in its open state.
  • the second cylinder chamber 38 is in fluid communication with the first cylinder chamber 37.
  • the fluid communication is provided by an equalization passage 32.
  • the equalization passage 32 includes longitudinal bore through the piston 31.
  • the equalization passage 32 may be formed completely within the ejector 1. It is integrated in the ejector 1 as such.
  • the pilot valve 50 includes a valve seat 51, a valve member 52, and an actuator 53.
  • the actuator 53 is configured to switch the pilot valve 50 between an open state and a closed state thereof.
  • the pilot valve 50 is a solenoid valve.
  • the actuator 53 is a solenoid actuator.
  • the pilot valve 50 is a part of the ejector 1.
  • the valve seat 51 may be integrally formed with the housing 70 or an insert fixed to the housing.
  • the valve seat 51 is mounted within the top cover 76.
  • a (minimum) flow cross-section A pci of the chamber inlet 36 is larger than a (minimum) flow cross-section A eq of the equalization passage 32.
  • the flow cross-section A pci of the chamber inlet 36 may be at least 5 times, especially at least 10 times, the flow cross-section A eq of the equalization passage 32.
  • the flow cross-section A pci of the chamber inlet 36 is the sum of the cross-sectional areas of the bores constituting the chamber inlet 36, which are formed in the cylinder insert 77.
  • the fluid pressure in the first cylinder chamber 37 at least substantially corresponds to the primary pressure at the primary inlet 2.
  • the fluid pressure in the first cylinder chamber 37 forces the piston 31 (along the longitudinal direction L) towards the top cover 76 and hence the needle 20 towards its opened position, against a resilient force provided by a resilient member 33.
  • the resilient member 33 is a coil spring.
  • fluid is supplied at the secondary inlet 7 with a secondary pressure.
  • the secondary pressure is less than the primary pressure at the primary inlet 2 but higher than an outlet pressure at the fluid outlet 12. In other words, there is a pressure drop from the primary pressure to the secondary pressure.
  • This pressure drop is used for jetting the fluid from the primary inlet chamber 3 through the nozzle 5 into the convergent mixing portion 6 when the needle 20 is in its opened position.
  • the fluid jetted out of the nozzle 5 has a high velocity.
  • the ejection through the nozzle 5 results in a pressure drop from the primary inlet chamber 3 to the convergent mixing portion 6.
  • fluid provided at the secondary inlet 7 is sucked from the secondary inlet chamber 8 through a secondary fluid passageway 9 into the convergent mixing portion 6.
  • the fluid from the primary inlet 2, which is ejected by the nozzle 5, and the fluid sucked from the secondary inlet chamber 8 mix in the convergent mixing portion 6 and the cylindrical mixing portion 10.
  • the pilot valve 50 is in its open state at the beginning.
  • a small fluid flow from the first cylinder chamber 37 to the second cylinder chamber 38 via the equalization passage 32 occurs.
  • the pressure drop is sufficiently high for holding the piston 31 in abutment with the top cover 76 against the restoring force of the resilient element 33.
  • the flow cross-section A eq of the equalization passage 32 is comparatively small. It may be less than 10 mm 2 , e.g. in the range from 0,5 mm 2 to 4 mm 2 . Additionally or alternatively, a value corresponding to the square of a length L eq of the equalization passage 32 (along a flow direction therethrough) may be at least 15 times, for example at least 25 times, the flow cross-section A eq of the equalization passage 32 (L eq 2 ⁇ 15*A eq ). The equalization passage 32 exhibits considerable flow resistance.
  • equalization passage 32 has a cylindrical shape, its flow cross-section A eq is ⁇ *(D eq /2) 2 , wherein D eq is a diameter of the equalization passage 32.
  • the flow cross-section A eq of the equalization passage 32 can be larger or the same as a (minimum) flow cross-section A dp of the drain passage (when the pilot valve 50 is in its open state).
  • an intermediate pressure occurs in the second cylinder chamber 38.
  • the intermediate pressure is lower than the pressure in the first cylinder chamber 37 (which may at least substantially correspond to the primary pressure).
  • the intermediate pressure is larger than the secondary pressure.
  • the exact value of the intermediate pressure depends, inter alia, on the flow resistance and hence on the flow cross-section A eq of the equalization passage 32 as well as on a flow resistance and hence on the flow cross-section A dp of the drain passage and on a ratio A eq /A dp .
  • the flow resistance of the drain passage is considerably smaller than the flow resistance of the equalization passage 32.
  • the flow cross-section A eq of the equalization passage 32 may be larger than the flow cross-section A dp of the drain passage (A eq /A dp > 1). Especially, the flow cross-section A eq of the equalization passage 32 may be in the range from 1,2 to 2,5 times the flow cross-section A dp of the drain passage (1,2* A dp ⁇ A eq ⁇ 2,5* A dp ). The flow resistance of the equalization passage 32 is smaller than the flow resistance of the drain passage. However, the pressure-drop from first cylinder chamber 37 to the second cylinder chamber 38 is smaller in that case.
  • the intermediate pressure in the second cylinder chamber 38 is less than pressure in the first cylinder chamber 37 when the pilot valve 50 is in its open state. In other words, there is nevertheless the small pressure drop.
  • the small pressure drop remains due to the flow resistance exhibited by the equalization passage 32 and due to ongoing discharge of fluid out of the second cylinder chamber 38.
  • the ejector 1 may be configured such that a pressure drop from the first cylinder chamber 37 to the second cylinder chamber 38 (i.e. a pressure drop along the equalization passage 32) is less than 10 bar, especially less than 3 bar, in normal operation if the pilot valve 50 after the pilot valve 50 is open for at least 0,2 s.
  • the ejector 1 may be configured such that an opening time of the needle 20 is at least 0,5 s in normal operation, especially at least 1 s.
  • the opening time may be a time needed for the movement of the needle 20 from its closed position to its opened position in normal operation.
  • the (minimum) flow cross-section A dp of the drain passage may correspond to a flow cross-section A pv of the pilot valve 50 when the pilot valve 50 is in its open state.
  • the intermediate pressure is less than the pressure in the first cylinder chamber 37.
  • the needle 20 is kept in its opened position while the pilot valve 50 remains open.
  • the ejector 1 is configured such that, in this situation, the force on the piston 31 resulting from the pressure difference between the intermediate pressure in the second cylinder chamber 38 and the pressure in the first cylinder chamber 37 is sufficient to (at least substantially) overcome the resilient force of the spring 33.
  • the pilot valve 50 is closed in this situation. No more fluid can be drained from the second cylinder chamber 38 to the secondary inlet chamber 8.
  • the pressure in the second cylinder chamber 38 increases towards the pressure in the first cylinder chamber 37 (which may at least substantially correspond to the primary pressure).
  • the resilient member 33 urges the piston 31 away from the top cover 76.
  • the piston 31 start to move along the longitudinal direction L towards the needle seat 26.
  • the needle 20 starts to move along the longitudinal direction L towards the needle seat 26 (i.e. towards its closed position).
  • the flow cross-section A eq of the equalization passage 32 is small compared to a piston area A P of the piston 31.
  • the piston area A P may correspond to at least 1000 times, e.g. to at least 1600 times, especially to at least 2100 times, the flow cross-section A eq of the equalization passage 32. This limits a movement speed of the piston 31.
  • the ejector 1 may be configured such that a closing time of the needle 20 is at least 1 s in normal operation, especially at least 2 s.
  • the closing time may be a time needed for the movement of the needle 20 from its opened position to its closed position in normal operation.
  • the piston area A P can be in the range from 2000 mm 2 to 10000 mm 2 .
  • piston 31 has a rotationally symmetric basic shape, its flow cross-section A p is ⁇ *(D p/2 ) 2 , wherein D p is a diameter of the piston 31.
  • the needle 20 abuts the needle seat 26.
  • the fluid connection from the primary inlet chamber 3 to the nozzle 5 (and hence from the primary inlet 2 to the nozzle 5) is blocked. No more fluid is ejected by the nozzle 5. Accordingly, no further fluid is sucked from the secondary inlet 7 into the convergent mixing portion 6.
  • the pilot valve 50 is opened again. Fluid is discharged from the second cylinder chamber 38 to the secondary inlet chamber 8 and the pressure in the second cylinder chamber 38 decreases towards the intermediate pressure mentioned above. Due to the pressure drop from the first cylinder chamber 37 and the second cylinder chamber 38, the piston 31 starts to move along the longitudinal direction L such that the needle 20 is retracted from the needle seat 26 towards the opened position.
  • a cross-sectional area A nsz of the needle seat 26 (a needle seat area A ns ) is only a bit larger than a (minimum) flow-cross section A noz of the nozzle 5.
  • the needle seat area A nsz may be in the range from 1,005 to 1,4 times the flow-cross section A noz of the nozzle 5. This allows for the needle 20 having a small diameter.
  • a flow resistance for fluid flowing from the primary inlet 2 to the nozzle 5 if the needle 20 is in its opened position is particularly low.
  • the comparatively small needle seat area A nsz ensures smooth and precise beginning of the transition from the closed position of the needle 20 to its opened position.
  • an increased initial force is required for starting the transition from the closed position to the opening position (i.e. from retracting the needle 20 from the closed position, particularly from abutment with the needle seat 26).
  • the force needed for further retraction of the needle 20 may decline.
  • the initial force depends, inter alia, on a size of a contact area between the needle 20 and the needle seat 26.
  • the initial force must be provided by the actuating mechanism 30. It is beneficial that the needle seat area A nsz is as close as possible to the flow-cross section A noz of the nozzle 5. This reduces the required initial force. As a consequence, a smaller and less expensive actuating mechanism 30 can be used.
  • the small needle seat area A ns reduces the risk of unintentional lift-off of the needle 20 from the needle seat 26 in the case of pressure peaks applied from the secondary inlet 7 and our the outlet 12.
  • the needle seat 26 has a circle-shape, the needle seat area A nsz is the area encircled by the needle seat 26 and corresponds to ⁇ *(D ns /2) 2 , wherein D ns is a diameter of the needle seat 26.
  • the flow cross-section A noz can be at least 50 mm 2 . This corresponds to a diameter of 8,0 mm if the nozzle 5 is formed rotationally symmetric.
  • the flow cross-section A noz of the nozzle 5 can be in the range from 70 mm 2 to 150 mm 2 .
  • an end portion of the needle 20 at the side of the needle seat 26 includes, seen along the longitudinal direction L, a needle tip 21, a first conical needle portion 22, and a second conical needle portion 24.
  • a taper angle of the first conical needle portion 22 is larger than a taper angle of the second conical needle portion 24.
  • an annular edge 23 is formed at the border between the first conical needle portion 22 to the second conical needle portion 24. (Only) the annular edge 23 abuts onto the needle seat 26 when the needle 20 is in its closed position.
  • the needle 20 can be made of Aluminum or an aluminum alloy.
  • the flow resistance of the drain passage is larger than the flow resistance of the equalization passage 32. This helps to ensure slow and controlled opening of the ejector 1.
  • the flow cross-section A pv of the pilot valve 50 may be smaller than the flow cross-section A eq of the equalization passage 32. Additionally or alternatively, the flow cross-section A pv of the pilot valve 50 (in its open state) may be less than 1,8 mm 2 .
  • the piston area A P of the piston 31 may be larger than a squared value of a stroke of the piston rod.
  • the stroke of the piston rod is the same as the stroke S of the needle 20.
  • the piston area A P may correspond to at least 8 times, especially at least 11 times, the squared value of the stroke S (A P ⁇ 8*S 2 , especially A P ⁇ 11*S 2 ).
  • the axial displacement of the piston 31 by the stroke S corresponds to a large change of the volumes of the first cylinder chamber 37 and the second cylinder chamber 38. This helps to ensure slow movement of the piston 31 and hence the needle 20 during transitions between the opened position and the closed position.
  • a pronounced synergistic effect can be obtained by combining this aspect with the aspect explained above, according to which the flow cross-section A eq of the equalization passage 32 may be small compared to the piston area A P of the piston 31.
  • the piston area A P of the piston 31 may be large compared to the needle seat area A ns . This reduces the influence of the additional lifting force on the opening and results in smoother opening.
  • the nozzle 5 is formed directly downstream of a nozzle inlet 4.
  • the nozzle inlet 4 extends the longitudinal direction L and tapers towards the nozzle 5. In more detail, it may extend along the central axis C as in the figures.
  • the nozzle inlet 4 is configured to guide the fluid supplied at the primary inlet 2 into the nozzle 5. More precisely, it guides the fluid supplied at the primary inlet 2 from the primary inlet chamber 3 into the nozzle 5 (when the needle 20 is in its opened position).
  • the nozzle inlet 4 can be a conical nozzle inlet.
  • a taper angle of the nozzle inlet 4 is smaller than the taper angle of the first conical needle portion 22 but larger than the taper angle of the second conical needle portion 24 (e.g., see Fig. 4 ).
  • the needle seat 26 and the nozzle 5 are formed in the same component, namely in a nozzle insert 27.
  • the nozzle insert 27 is a one-piece component. It is mounted in the insert assembly holder 78.
  • the nozzle insert 27 includes the upstream nozzle inlet 4 and the nozzle 5.
  • the nozzle insert 27 can be made of a material having a higher hardness than a material of the needle 20.
  • the nozzle insert 27 can be made of iron.
  • a length W of the nozzle inlet 4 is larger than the stroke S.
  • the length of the nozzle inlet 4 may correspond to at least 1,8 times the stroke S. This ensures that the end portion of the needle 20 still protrudes into the nozzle inlet 4 even if the needle 20 is in its opened position. Accordingly, the needle 20 helps, in its opened position, to guide the fluid from the primary inlet chamber 3 smoothly into the nozzle inlet 4 and further into the nozzle 5 and to reduce turbulences.
  • a distance Z between the nozzle 5 and the needle seat 26 along the longitudinal direction L (and according to a local flow direction) is small. It may be less than 0,8*(A noz / ⁇ ) 0,5 . In other words, the needle seat 26 may be formed directly upstream of the nozzle 5. This facilitates to keep the needle seat area A nsz small and to reduce the flow resistance.
  • the stroke S may correspond to at least 2*(A noz / ⁇ ) 0,5 , which corresponds to the D noz if the nozzle is of rotationally symmetric shape.
  • the stroke S may correspond to at least 2,8*(A noz / ⁇ ) 0,5 .
  • the ejector 1 may be configured such that the flow cross-section A noz of the nozzle 5 constitutes a minimum flow cross-section between the primary inlet 2 and the convergent mixing portion 6 when the needle 20 is in its opened position.
  • the needle 20 never protrudes downstream of the nozzle 5. In other words, the needle 20 never protrudes into the convergent mixing portion 6.
  • the depicted embodiment of the ejector 1 provides a check valve functionality for preventing fluid flow from the outlet 12 to the secondary inlet 7.
  • the ejector 1 provides a check member 80 for closing a fluid connection between the mixing portion (in more detail, the convergent mixing portion 6) and the secondary inlet chamber 8. If the ejector 1 is in its closed state, the check member 80 abuts on a check valve seat 79 and blocks fluid flow from the outlet 12 to the secondary inlet 7. If the ejector 1 is in its open state, fluid is sucked from the secondary inlet 7 through the secondary inlet chamber 3 and the secondary fluid passageway 9 into the convergent mixing portion 6. Thereby, the check member 80 is displaced along the longitudinal direction L and lifts off from the check valve seat 79.
  • An annular end face of the cylinder insert 77 and a corresponding abutment area on the top cover 76 are grounded flat.
  • An elastic member 90 (which is a coil spring in this embodiment) biases the cylinder insert 77 against the top cover. Hence, no significant fluid leakage or pressure propagation can occur directly from the primary inlet chamber 3 to the second cylinder chamber 38.
  • the elastic member 90 is arranged in the primary inlet chamber 3 and coaxially to the needle 20. It is squeezed between the top cover 76 and the insert assembly holder 78.
  • a filter 91 is provided between the primary inlet 2 and the nozzle inlet 4.
  • the filter 91 is provided in the primary inlet chamber 3 around the elastic member 90, wherein the elastic member supports (backs up) the filter 91.
  • the top cover 76 is removably fixed to the main sleeve 71 by screws. If the top cover 76 is detached, the cylinder insert 76 can be taken out of the main sleeve 71 for maintenance.
  • the depicted embodiment is only an exemplary one and the elements can be implemented in other manners and geometries.
  • the end portion of the needle 20 may be formed with another shape (e.g. convexly tapered), the needle seat 26 and the nozzle 5 can be formed two by separate elements, and the like.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Jet Pumps And Other Pumps (AREA)
EP22190394.1A 2022-08-15 2022-08-15 Auswerfer, der einen betätigungsmechanismus mit einem vorsteuerventil und einem ausgleichskanal zwischen zylinderkammern aufweist Pending EP4325142A1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP22190394.1A EP4325142A1 (de) 2022-08-15 2022-08-15 Auswerfer, der einen betätigungsmechanismus mit einem vorsteuerventil und einem ausgleichskanal zwischen zylinderkammern aufweist
PCT/EP2023/072386 WO2024038014A1 (en) 2022-08-15 2023-08-14 Ejector having an actuation mechanism with a pilot valve and an equalization passage between two cylinder chambers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP22190394.1A EP4325142A1 (de) 2022-08-15 2022-08-15 Auswerfer, der einen betätigungsmechanismus mit einem vorsteuerventil und einem ausgleichskanal zwischen zylinderkammern aufweist

Publications (1)

Publication Number Publication Date
EP4325142A1 true EP4325142A1 (de) 2024-02-21

Family

ID=82940010

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22190394.1A Pending EP4325142A1 (de) 2022-08-15 2022-08-15 Auswerfer, der einen betätigungsmechanismus mit einem vorsteuerventil und einem ausgleichskanal zwischen zylinderkammern aufweist

Country Status (2)

Country Link
EP (1) EP4325142A1 (de)
WO (1) WO2024038014A1 (de)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1421843A (en) * 1914-09-14 1922-07-04 Westinghouse Electric & Mfg Co Fluid-translating device
US20040040340A1 (en) * 2002-08-29 2004-03-04 Masayuki Takeuchi Refrigerant cycle with ejector having throttle changeable nozzle
EP1722107A1 (de) * 2004-03-01 2006-11-15 Toyota Jidosha Kabushiki Kaisha Ejektor und brennstoffzellensystem damit
EP1923575A2 (de) 2006-11-16 2008-05-21 Honeywell International Inc. Servogesteuerte Dampfstrahlpumpe mit variabler Geometrie
JP4134918B2 (ja) 2004-02-18 2008-08-20 株式会社デンソー エジェクタ
US7841193B2 (en) 2006-02-16 2010-11-30 Denso Corporation Refrigerant flow-amount controlling device and ejector refrigerant cycle system using the same
WO2012012501A2 (en) * 2010-07-23 2012-01-26 Carrier Corporation High efficiency ejector cycle
DE112015003818T5 (de) * 2014-08-21 2017-05-04 Denso Corporation Ejektor und Ejektorkältekreislauf
WO2018159320A1 (ja) 2017-03-02 2018-09-07 株式会社デンソー エジェクタモジュール

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1421843A (en) * 1914-09-14 1922-07-04 Westinghouse Electric & Mfg Co Fluid-translating device
US20040040340A1 (en) * 2002-08-29 2004-03-04 Masayuki Takeuchi Refrigerant cycle with ejector having throttle changeable nozzle
JP4134918B2 (ja) 2004-02-18 2008-08-20 株式会社デンソー エジェクタ
EP1722107A1 (de) * 2004-03-01 2006-11-15 Toyota Jidosha Kabushiki Kaisha Ejektor und brennstoffzellensystem damit
US7841193B2 (en) 2006-02-16 2010-11-30 Denso Corporation Refrigerant flow-amount controlling device and ejector refrigerant cycle system using the same
EP1923575A2 (de) 2006-11-16 2008-05-21 Honeywell International Inc. Servogesteuerte Dampfstrahlpumpe mit variabler Geometrie
WO2012012501A2 (en) * 2010-07-23 2012-01-26 Carrier Corporation High efficiency ejector cycle
DE112015003818T5 (de) * 2014-08-21 2017-05-04 Denso Corporation Ejektor und Ejektorkältekreislauf
WO2018159320A1 (ja) 2017-03-02 2018-09-07 株式会社デンソー エジェクタモジュール

Also Published As

Publication number Publication date
WO2024038014A1 (en) 2024-02-22

Similar Documents

Publication Publication Date Title
EP3239570B1 (de) Volumensteuerungsventil
JP5802539B2 (ja) 複合弁
EP1380750B1 (de) Brennstoffeinspritzventil
US11682776B2 (en) Metering valve and jet pump unit for controlling a gaseous medium
US20100000037A1 (en) Speed Regulated Pipeline Pig
JPS6172867A (ja) 内燃機関の燃料噴射ポンプ
US8397758B2 (en) Valve
EP1001197A1 (de) Steuerbares Druckventil
GB2272747A (en) Solenoid valve
US20100319660A1 (en) Fuel Injector Having An Additional Outlet Restrictor Or Having An Improved Arrangement Of Same In The Control Valve
EP2728161A1 (de) Auslassventilanordnung
EP1608867B1 (de) Anordnung in einer kraftstoffeinspritzvorrichtung
EP4325142A1 (de) Auswerfer, der einen betätigungsmechanismus mit einem vorsteuerventil und einem ausgleichskanal zwischen zylinderkammern aufweist
DE102006000256A1 (de) Ventilvorrichtung und Fluideinspritzventil
EP2292918B1 (de) Brennstoffeinspritzvorrichtung mit Mess-Servoventil für einen Verbrennungsmotor
CZ20013596A3 (cs) Vstřikovací tryska
US20200332913A1 (en) Valve device
US8141579B2 (en) Valve with cushioned opening system
CN110486512B (zh) 一种安全阀
GB2336628A (en) A fuel injector, for an I.C. engine, having a three way two position needle control valve
US11359728B2 (en) Anti-cavitation valve assembly
CN105829698B (zh) 控制阀装置
KR100499262B1 (ko) 파일롯 포펫 릴리프 밸브
EP2320061A1 (de) Kraftstoffeinspritzdüse
KR102699358B1 (ko) 차고 조절 장치

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20240312

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR