Valve with phase change material for flow control of a refrigerant and element for a valve

Abstract

The invention relates to a valve (1) adjustable by means of an actuator (3) for controlling the flow rate of a refrigerant in a refrigerant circuit, the valve (1) comprising a housing, the actuator (3) by means of which a flow rate of refrigerant can be adjusted, and an electronic circuit board (15) for controlling the actuator (3), wherein the valve (1) has at least one area (16) in which a phase change material (17) is arranged, the phase change material (17) being configured to perform a phase change from a first phase to a second phase upon falling below a predetermined temperature, releasing latent heat. The invention also relates to an element (19) for a valve (1).

Description

[0001] The invention relates to a valve adjustable by means of an actuator for controlling the flow rate of a refrigerant in a refrigerant circuit, wherein the valve comprises a housing, the actuator by means of which a flow rate of refrigerant can be adjusted, and an electronic circuit board for controlling the actuator. The invention also relates to an element for a valve, in particular for arrangement on the valve.

[0002] CN116792544A shows a carbon dioxide safety valve with antifreeze and anti-blocking agents. The carbon dioxide safety valve has a heat-preserving protective layer to prevent heat exchange between the carbon dioxide safety valve and its environment.

[0003] German patent DE 10 2008 030 403 A1 discloses a PCV valve (PCV: Positive Crankcase Ventilation) of a motor vehicle. The PCV valve comprises a stepper motor which, when energized, generates heat that is dissipated via a valve housing to a valve seat, thereby warming the seat and protecting it from freezing.

[0004] US 2020 / 0041180A1 discloses an expansion valve comprising a valve body, limiting unit and heating unit, wherein there is a variable distance in the actuating space between the limiting unit and the valve seat, which is kept ice-free when reduced by heating in order to maintain a flow condition.

[0005] US 2012 / 0112114A1 discloses a valve for preventing frost damage comprising a housing coupled to a pipe connection with a drain chamber, water inlet and outlet openings, and a storage chamber containing phase-change material which, when solidifying, moves a piston to drain water before freezing.

[0006] The background of the invention is the potential prohibition or restriction of PFAS (per- and polyfluoroalkyl substances, per- and polyfluorinated alkylene compounds) as refrigerants in refrigerant circuits, particularly in refrigerant circuits and / or air conditioning systems of motor vehicles. Carbon dioxide, propane, butane, or corresponding gas variants or alternatives are considered as refrigerants for PFAS. Hereinafter, reference is made only to carbon dioxide (CO2), unless otherwise specified. This reference does not, however, restrict the use of other gas variants.

[0007] Unlike PFAS, carbon dioxide as a refrigerant exhibits significantly lower temperatures in certain sections of a refrigerant circuit. Particularly during flow, such as when expanding, carbon dioxide reaches low (static) temperatures of up to minus 50 degrees Celsius. A valve used to control the flow rate, for example, for the expansion or decompression of carbon dioxide, is typically made of metal. Compared to plastic, metal has a significantly higher thermal conductivity (and therefore also a significantly better "cold conductivity"). Such a valve usually includes a control board or electronic circuit board, for example, to control an actuator enclosed within the valve.Cooling of the electronic circuit board due to expansion can lead to thermoelectric voltages in the circuit board, thereby destroying it or possibly restricting or damaging its function.

[0008] The invention is based on the objective of providing a particularly robust or durable valve for flow control of a refrigerant in low-temperature applications, as well as an element for arranging on a valve to make it particularly robust against temperature fluctuations.

[0009] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments of the invention are described by the dependent patent claims, the following description, and the figures.

[0010] A first aspect of the invention relates to a valve adjustable by means of an actuator for controlling the flow rate of a refrigerant in a refrigerant circuit, wherein the valve comprises a housing, the actuator by means of which a flow rate of refrigerant can be adjusted, and an electronic circuit board for controlling the actuator.

[0011] To protect the aforementioned electronic circuit board and / or other components from thermal and / or mechanical stress, the valve has at least one region in which a phase-change material is arranged. This phase-change material is configured to undergo a phase change from a first phase to a second phase upon falling below a predetermined temperature, releasing latent heat. In other words, a phase-change material is arranged in at least one region of the valve such that, upon falling below a predetermined temperature in that region (for example, during operation of the valve), the phase-change material arranged there transitions from a first phase to a second phase, releasing latent heat or heat, thereby heating at least that region.

[0012] This offers the advantage that cooling during valve operation below the specified temperature can be prevented or at least delayed. Of course, the time required for heat conduction must be taken into account, meaning that the phase-change material will reach the temperature of the specified range with a time delay.

[0013] The phase change material or phase change materials of the invention are a group of materials used for heat storage. The phase change materials of the invention are designed such that a phase change or change of state occurs within a relevant temperature range, either upon reaching the predetermined temperature or below it. The predetermined temperature can be in a range of 0 to 10 degrees, particularly 1 to 5 degrees. During a phase change material transition, for example from a gaseous to a liquid state, the so-called enthalpy of vaporization is released during the transition of the phase change material, which has been cooled to its boiling point, from the gaseous phase to the liquid phase.Upon further cooling towards the melting point, the enthalpy of fusion or heat of fusion is released when the phase change material solidifies or freezes. The release of the enthalpy of vaporization and / or the enthalpy of fusion is intended to delay or prevent the housing from cooling below the boiling point (evaporation) and / or the melting point of the phase change material. For the purposes of this invention, suitable phase change materials include sodium acetate trihydrate (used in so-called "heat packs"), water, paraffins, fats, salts such as alum (salts of sulfuric acid with aluminum, gallium, indium, titanium, vanadium, chromium, manganese, iron, cobalt, rhodium, and / or iridium), sodium sulfate, and / or sodium hydroxide, to name just a few examples.Even if the melting point of the substances mentioned here as examples is significantly above the temperature range specified according to the invention, a phase change, for example from liquid to solid, can still occur significantly below the respective melting point if the substance is present as a supercooled melt. During a cooling process, the phase change material can exist in all three phases (solid, liquid, gaseous) in at least one region; for example, a portion may be in the gaseous phase, a portion in the liquid phase, and a portion in the solid phase, i.e., not a portion in all three phases. According to the invention, the phase change of the phase change material can occur from the first phase to the second and from the second to a third phase. In this example, the first phase is a gas phase, the second phase is a liquid phase, and the third phase is a solid phase.Alternatively, according to the invention, the first phase can be a liquid phase and the second a solid phase. The at least one region in which the phase change material is arranged means that the valve can have one or more regions which can be fluidically separated from one another. For example, such a region can be a cavity in the housing of the valve, which can also be referred to as the housing cavity, and which can have at least one bore for filling and / or draining the phase change material. This bore can be closed non-destructively and reversibly, for example by a sealing device such as a sealing screw.

[0014] The valve can include an electronic circuit board with a first connector, preferably a female connector, through which the valve can be connected to an electrical supply connection for providing the actuator with electrical energy. The electronic circuit board controls the actuator, which can move a shaft, i.e., a threaded rod or spindle, translationally as a result of a rotary motion. This, in turn, actuates a compensating piston, which allows the flow rate or quantity of preferably gaseous refrigerant to be adjusted before it is released through the valve. The actuator can be an electric motor known from the prior art. The components of the valve, i.e., the electronic circuit board, the actuator, the shaft, and the compensating piston, to name just a few, can be enclosed or encased by the valve housing.The housing is preferably made of metal. The housing can be divided into two or more parts, which can be connected to each other, for example, by screws.

[0015] The valve housing can be multi-part, meaning it can be composed of several housing parts, particularly three housing parts, for example, by screwing the housing parts together or into one another. Housing sections refer to lengthwise segments of the housing along a longitudinal direction. This longitudinal direction can extend from the electronic circuit board to the actuator or the compensating piston. Thus, a section can, for example, comprise one or more housing parts or sub-areas of different housing parts, i.e., extend across a junction between two housing parts.

[0016] The invention also includes embodiments or further developments that offer additional advantages.

[0017] A further development of the valve provides that at least one area includes a first section of the housing, meaning that a region containing phase-change material is provided by a first section of the housing, which encloses the electronic circuit board. In other words, the phase-change material can be arranged in the first section of the housing, which can, for example, comprise a first housing part, such as in the housing cavity, i.e., a cavity in or within a wall of the housing in the first section. The "housing cavity" does not refer to the volume enclosed or enclosed by the wall in which valve components, such as the electronic circuit board, are located. Additionally or alternatively, the phase-change material can be encapsulated in an element on an outer surface, i.e., a side of the housing wall facing the environment.This offers the advantage that if the first section of the housing cools below the specified temperature, the phase-change material located there can transition, either completely or partially, from a first phase (e.g., a liquid phase) to a second phase (e.g., a solid phase), thereby releasing latent heat to the first section of the housing, i.e., the part of the housing enclosed or contained by the first section. The specified temperature can be the melting point of the phase-change material. By releasing the enthalpy of fusion during the solidification of the phase-change material, cooling of the circuit board below the specified temperature can be at least delayed, thus keeping thermal stresses in the circuit board due to cooling particularly low. This can increase the functionality and / or lifespan of the circuit board.

[0018] A further development of the valve provides that at least one area includes a second housing section, meaning that an area containing phase-change material is provided by a second housing section, and the actuator is enclosed within this section. In other words, the phase-change material in the second housing section, which may comprise a second housing part or partially the first and partially the second housing part, can be located in a housing cavity or on the outside of the housing.

[0019] This offers the advantage that, if the valve cools down, the actuator's cooling below the specified temperature can at least be delayed, thus allowing the actuator to remain operational for a particularly long time. Cooling of the actuator can damage it or impair its function due to thermal stresses, for example, through deformation of the actuator components or through icing and the associated restricted movement. When the phase change temperature is reached or fallen below, for example, the melting point, which can be the specified temperature, the phase change material can release enthalpy of fusion as heat. The phase change material can be present in at least one of the two sections, i.e., in the first or the second section, or in both sections.

[0020] A further development of the valve provides that the actuator has a shaft designed to actuate a compensating piston of the valve, particularly when the actuator is activated. This allows the flow rate or the amount of refrigerant to be expanded by the valve to be adjusted. The shaft is designed as a hollow shaft, and a cavity within the hollow shaft contains a phase-change material. In other words, the cavity in the shaft is filled with the phase-change material. When the valve is operated, the phase-change material in the hollow shaft can act as a thermal buffer, thus advantageously delaying the spread of cold, for example, to the electronic circuit board.This allows the valve (especially the electronic circuit board and / or the actuator) to remain operational for a particularly long period. The at least one area can therefore contain the phase-change material in the first section and / or the second section and / or in the hollow shaft.

[0021] A further development of the valve provides that at least one area includes a connecting area arranged between two housing parts of the housing, i.e., an area containing phase-change material is provided by the connecting area, with the two housing parts being thermally connected to the connecting area. In other words, the phase-change material is arranged in a cavity which is bounded by the walls of the two housing parts.

[0022] This offers the advantage, analogous to the hollow shaft filled with phase change material, that the cooling of particularly critical components of the valve (for example, the electronic circuit board and / or the actuator) can be delayed, thus allowing the valve to be operated for a particularly long time or to be permeated by refrigerant for a particularly long time.

[0023] Therefore, at least one area can have the phase change material in the first section and / or in the second section and / or in the hollow shaft and / or in the connection area.

[0024] In particular, it is provided that the phase change material is arranged between the two housing parts, i.e., in the connection area, within the housing, specifically within the housing wall. A cavity can be formed between the two housing parts, especially when the two housing parts are assembled. This cavity can be filled with the phase change material, for example, through an opening in the housing (sealable, for example, by a sealing screw) in the connection area when the housing or valve is assembled. For example, one of the two housing parts can have a recess, and the other can have a further recess, which, when both housing parts are assembled (e.g., by screwing them together), form the cavity.“Thermally conductive connection” here means that the phase change material is in direct or immediate contact with at least one housing part, in particular with both housing parts.

[0025] Alternatively, an insulating layer can be arranged between two housing parts of the valve that are joined in the finished product. This insulating layer can be made of rubber, for example, natural, synthetic, and / or semi-synthetic rubber. This offers the advantage that thermal insulation between at least two valve housing parts can at least delay cooling or heat transfer, specifically from a warmer housing part to a cooler one.

[0026] Additionally or alternatively, it can be provided that the entire valve is encased with the phase change material; for example, the phase change material is encapsulated in an element, i.e., enclosed by it.

[0027] A second aspect of the invention relates to an element for a valve, particularly according to the first aspect of the invention. Advantages and advantageous developments of the first aspect of the invention are to be regarded as advantages and advantageous developments of the second aspect of the invention, and vice versa.

[0028] The valve element has a cavity, at least partially enclosed by a protective layer, which can also be referred to as the element cavity. This cavity can be filled with a phase-change material, and the protective layer forms a mounting area for the element, allowing it to be attached to or within the valve, at least indirectly. In other words, the element is intended to be mounted on the outside of the housing. Mounting the element creates a cavity, which, for clarity, is referred to here as the "element cavity" and can be filled with the phase-change material.The protective layer can be made of plastic or metal, for example, and form or define at least a partially enclosed cavity. This cavity may be open on one side, which is closed, for example, by the valve housing when the element is attached to the valve. The phase change material can be placed in the at least partially enclosed cavity of the element or element cavity before the element is attached to the valve. The phase change material can, for example, be fluidically sealed in a plastic film pouch and inserted into the element cavity. When the element filled with the phase change material is attached to the valve, the phase change material can be thermally connected to the valve housing, for example, directly or via the plastic film.This offers the advantage that commercially available or previously known valves can be subsequently thermally hardened for use in refrigerant circuits where particularly low temperatures may occur, thus making them insensitive to low temperatures or providing a particularly long service life. The valve or the housing can have a cylindrical section, i.e., rotationally symmetrical with respect to the longitudinal direction. The element can be rotationally symmetrical with respect to a longitudinal axis. This allows the element to be fitted over the cylindrical part of the valve housing or a cylindrical part of the valve for attachment. The protective layer can at least partially define the element cavity and form the attachment area in at least one region.In the case of a rotationally symmetrical design of the element, the mounting area can, for example, consist of two mounting sections arranged next to the cavity, each of which can, for example, have a hose clamp known from the prior art, or by means of which the mounting sections, i.e., the entire mounting area, can be attached to the valve or the valve housing. "At least indirectly attachable" here means that, for example, bores can be provided in the mounting area or in the mounting sections, whereby the housing can have corresponding bores, and thus the element can be attached to the valve, for example, by means of screws.

[0029] A further development of the element provides that the protective layer has at least one opening through which the phase change material can be poured into the element cavity. The phase change material can, for example, be in liquid form at room temperature (20 degrees Celsius) and be poured into the element cavity through the at least one opening, which can be sealed fluidically, for example, by means of a sealing screw. The protective layer can have two openings in the area of ​​the cavity to make filling the element cavity particularly easy, for example, when both openings are open, i.e., when the sealing screws have been removed from both openings, and the phase change material is poured in through one opening, while air can escape from the element cavity through the other opening.In particular, it can be provided that the phase change material is arranged in fluidically tightly sealed hollow spheres with a diameter of 0.1 to 4 millimeters and that the phase change material is encased by the hollow spheres through which at least one opening can be inserted into the element cavity.

[0030] A further development of the element provides for a partially open element cavity, so that the phase change material, when filled with the element and attached to or within the valve, is in direct contact with a wall of the valve or valve housing. In other words, the element cavity is only fully enclosed once the element is attached to or within the valve. For this purpose, the element can, for example, have a bulge whose open side is closed by the valve housing when the element is attached. The direct contact of the phase change material with the valve or a wall of the valve housing offers the advantage of particularly efficient heat transfer between the housing (i.e., the valve) and the phase change material.Thus, when the valve cools down, especially when the valve is in operation, the specified temperature in the phase change material can be undershot particularly quickly, and the heat released by the resulting phase change of the phase change material can be transferred to the valve particularly quickly.

[0031] A further development of the element provides that the protective layer, particularly in the case of a partially open element cavity, has a seal on one side that is in contact with the wall when the element is attached. In other words, the seal is positioned between the protective layer and the wall when the element is attached. The seal is designed to completely close off the element cavity, which is fully enclosed when the element is attached to the valve, from the environment in a fluid-tight manner, i.e., liquid-tight and / or gas-tight. The seal can be designed as is known from the prior art for heating circuits or refrigerant circuits. This offers the advantage that the phase change material cannot escape from the cavity or element cavity when the element is attached to the valve.Additionally or alternatively, as already mentioned, the phase change material can be fluidically sealed in a closed bag, for example made of plastic film, and enclosed by this bag, positioned in the element cavity before the element is attached to the valve. In this case, the element can serve as a support structure, ensuring that the phase change material rests in a predetermined area, for example against a wall of the first housing part, and remains there.

[0032] A further development of the element provides that the cavity or element cavity is completely enclosed or surrounded by the protective layer and that the element has an adhesive surface by means of which it can be bonded to a wall of the valve. This offers the advantage of significantly reducing the effort required to attach the element to or within the valve. The cavity or element cavity can be completely enclosed by the protective layer; for example, if phase-change material is located in the cavity, it can be completely encased by the protective layer, which may be made of metal. An adhesive surface can be provided, at least in part, on a wall or side of the element that must be in contact with the valve housing during attachment, by means of which the element can be attached to the valve housing.In other words, the mounting area includes the adhesive film by means of which the element can be attached to the valve. In one embodiment, the phase change material can be fluidically sealed in or encased in a bag made of, for example, plastic film, with the adhesive surface located on one side of the plastic film, which can then be attached to the housing by means of this adhesive surface. In this embodiment, the element can have only the plastic film as a protective layer. This offers the advantage that a seal can be omitted.In particular, it may be provided that the element is designed as an adhesive pad, i.e., a fluidically sealed plastic bag in which the phase change material is arranged, which has an adhesive surface or adhesive layer on one side or on one side of the plastic film forming the plastic bag, by means of which the element or the adhesive pad can be attached to the valve, in particular can be wrapped around a cylindrical part or housing part of the valve and remains there due to the adhesive force of the adhesive surface.

[0033] The invention is summarized below.

[0034] It is known from the prior art that valves in refrigeration circuits, which may be converted in the future, either generally or in the automotive industry, due to the potential ban on PFAS or the restriction to CO2 (carbon dioxide), propane, butane, or corresponding alternative gases, can ice up during expansion, similar to gas cylinders and gas grills. The following description focuses solely on CO2 as an example, without considering other possible gas variants such as propane or butane that can be used in refrigeration circuits. These valves in automotive applications are electronically controlled, with the electronics housed within the valve casing and an actuator also located within the valve. The valves are made entirely of metal, as CO2 systems can only be implemented using metal constructions, since all other materials are either leaky to CO2 or exhibit increased permeability to it.

[0035] These metal constructions are susceptible to icing because they are excellent heat conductors, further narrowing the operating window before the valve has to shut down and thus disrupting the CO2 system's cycle. Either the electronics, also known as the circuit board, or the actuator within the valve freezes. Both lead to premature shutdown of the expansion process, which in turn shuts down the cycle or shifts its timing, negatively impacting the CO2 system's efficiency. Control electronics, also known as circuit boards, in valves used in CO2 refrigeration cycles are particularly prone to icing. This can cause the electronics or actuator to shut down or malfunction, severely impacting the cycle or significantly reducing its efficiency.When electronics and / or actuators are partially encapsulated or coated with PCM (phase change material), this effect can be significantly delayed or occur later during valve operation. This is because the PCM stores heat or latent heat, which is then released when the valve is subcooled (icing or cooling below a desired temperature threshold or preset temperature). Therefore, the electronics and / or actuator can keep the valve open for a significantly longer time, allowing the cycle to run continuously without interruption or shutdown.

[0036] The following describes possible implementations for preventing or delaying valve icing. For example, the electronics can be heated by a heat sink, particularly the phase change material (PCM) in valves for CO2 and / or hydrogen systems that control the refrigerant circuit. This heating, for example, through a phase change of a phase change material, serves to ensure longer valve operation. These valves are typically shut down prematurely, for example, in the event of icing, to prevent electronic and / or component failures. Consequently, the cycle can no longer be operated optimally, resulting in a significant loss of efficiency.Additionally or alternatively, the valve can be actively controlled depending on environmental properties, such as temperature and / or humidity, and / or material properties, such as the properties of the PCM or the housing material, such as temperature, the heat storage medium and / or the phase change material.

[0037] The following aspects can be provided individually or in combination: The electronic circuit board can be encapsulated with PCM; the housing, for example around the actuator, can be lined internally with PCM or be multi-layered and contain PCM internally; a shaft of the actuator can be designed as a hollow shaft filled with PCM; insulation, in particular thermal insulation and / or PCM, can be arranged in a transition or intermediate area of ​​the housing between a lower housing part or section and an upper housing part or further section of the housing to keep it warm; an additional layer of phase-change material can be provided.which can assume a different phase or undergo a phase change under the influence of temperature and can change back again at cold temperatures, for example to a solid phase. The electric motor or actuator controls the icing process depending on the material properties of the PCM and / or an outside or ambient temperature and / or humidity, in order to maximize heat input into the PCM (PCM is just a term that does not have to be a specific material, because every material is a PCM since it changes its phase and absorbs energy; for example, steel in a crash is PCM because it becomes hyperplastic and liquefies). An additional layer, which can also be called a phase change material, can consist of several components and in particular contain thermally conductive particles, such as metal shavings. An additional layer can be liquid, paste-like, or a bulk material and in particular be gaseous.An outer part of the component, valve, or housing can be partially coated with at least one of the aforementioned additional layers. The valve (electronics) can have a cavity or housing cavity with a feed opening or at least one opening into which the PCM is filled, wherein the cavity or housing cavity or the opening can subsequently be closed again (after filling, for example). This closure may, for example, only be provided if the component is operated upside down or rotated, as otherwise it would leak. It may also be closed if the PCM becomes gaseous and would otherwise evaporate through the opening. Additionally or alternatively, adhesive pads or elements with an adhesive layer may be provided, which may consist of at least three layers, for example, wherein one additional layer may not be in direct contact with the component, housing, or valve.but only indirectly, for example, via the adhesive layer. Additionally or alternatively, an element can be provided that is glued and / or mechanically attached to the component, housing, or valve, and the additional layer is in direct contact with the component. In this case, a protective layer of the additional layer can be provided on the outside, which is used for heat conduction to the outside, for example, to the environment, and can have, for example, particularly high thermal conductivity. This protective layer of the additional layer can be made of plastic and / or metal.

[0038] Additionally or alternatively, it may be provided, individually or in combination with some or all aspects, that the phase change material can be embedded in hollow spheres, wherein the sealing or closure of a respective cavity of the hollow spheres can be liquid-tight and / or gas-tight, or alternatively, the hollow spheres can be manufactured sealed with the phase change material, i.e., without an opening through which they need to be filled with the phase change material and then sealed. Depending on the size of the bearing or cavity, or the housing cavity or element cavity, the sealing of the openings (of the housing cavity) or recesses of the housing can be implemented, for example, by plugs that are inserted and / or by sealed covers and / or by glued cover plugs.Additionally or alternatively, supplementary shells can be provided, which are fitted, screwed, and / or glued onto the bearing, cavity, housing cavity, or element cavity. The material or phase-change material that is stored in the at least one opening, cavity, housing cavity, or element cavity can be a combination of several materials and may also contain thermally conductive components, such as metal shavings, to increase the stiffness of the bearing. Additionally or alternatively, the balls can be designed as hollow spheres to allow the material or phase-change material to be stored directly within them.

[0039] The invention also includes combinations of the features of the described embodiments or further developments. The invention thus also includes implementations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0040] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 Schematic sectional view of a section through a valve for flow control of a refrigerant with phase change material arranged in a first housing part of a housing of the valve; Fig. 2 Schematic sectional view of a section through a valve with phase change material arranged in a second housing part; Fig. 3 Schematic sectional view of a section through a valve with phase change material arranged in a shaft designed as a hollow shaft; Fig. 4 Schematic sectional view of a half section through a valve with an element arranged on a housing wall of the valve, showing an element cavity with phase change material in a first phase; Fig. 5 Schematic sectional view of a half section through the valve with an element arranged on the housing wall of the valve containing phase change material at least partially in a second phase; Fig. 6 Schematic sectional view of a half-section through a valve with an element arranged on a housing wall of the valve by means of an adhesive layer, with a protective layer completely enclosing an element cavity and with phase change material arranged in the element cavity in a first phase; Fig. 7 Schematic sectional view of a half-section through the valve with a phase change material element in a second phase arranged on the valve housing wall by means of the adhesive layer; and Fig. 8 Refrigerant circuit with valves used in multiple functions;

[0041] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0042] In the figures, identical reference symbols denote functionally equivalent elements.

[0043] Fig. Figure 1 shows an exemplary construction of a valve 1, in particular for adjusting the flow rate of, for example, a refrigerant to be expanded in a refrigerant circuit. A phase change material 17 can be arranged in a first section or first housing part 2 of a housing of the valve 1. The housing of the valve 1 can have three housing parts 2, 11, 6. Along a longitudinal direction 14, the valve 1 can have an electronic circuit board 15, which can be enclosed by a first housing part 2. The first housing part 2 can be at least partially, as shown in Figure 1. Fig. Figure 1 shows a servomotor 3. A second housing part 11 can be directly connected to the first housing part 2, which, as shown in Figure 1, comprises a servomotor 3. Fig. As shown in Figure 1, the actuator 3 can at least partially encompass the actuator 3. A shaft 5, encompassing the second housing part 11, can be connected to the actuator 3 in the longitudinal direction 14 and can be moved by the actuator 3. The shaft 5 can be supported by a ball bearing 4. A compensating piston can be connected to the shaft 5 in the longitudinal direction 14 and can be moved by the shaft 5 in the longitudinal direction 14, thereby allowing the flow rate of refrigerant through the valve 1 to be adjusted, for example, by moving or adjusting the compensating piston. As shown in Figure 1, the actuator 3 can be at least partially encompassed by the second housing part 11 and can be moved by the actuator 3. The shaft 5 can be supported by a ball bearing 4. Fig. As shown in Figure 1, the valve 1 can have supply ports 12 through which the valve 1 can be connected to a refrigerant circuit. One of the supply ports 12 can be an inlet and the other an outlet for refrigerant from the valve 1. As shown in Fig. As shown in Figure 1, the electronic circuit board 15 can have a connector, in particular a female connector, which can be connected to an electrical supply connector 13. The supply connector 13 can not only provide electrical energy for operating the valve 1, in particular for operating the actuator 3, but also transmit control signals to the electronic circuit board 15 for operating the actuator 3. When the valve 1 is operated, for example, triggered by a control signal transmitted via the supply connector 13, the electronic circuit board 15 can control the actuator 3, whereupon the actuator can move the shaft 5 and the compensating piston can be moved.This allows, enables, and / or allows a flow through the supply ports 12, where "adjustable" means that a flow rate, i.e., a mass flow and / or a volume flow of refrigerant, can be adjusted. As the refrigerant flows through the supply ports, encompassed by the third housing part 6, the valve 1 can cool down. In other words, when the valve 1 is operated, the flow from the supply ports 12 through the third housing part 6 to the second housing part 11 and finally to the first housing part 2 can decrease with increasing operating time, or the temperature of the valve 1 or the housing parts 2, 11, and 6 can decrease. To prevent damage to the electronic circuit board 15 due to subcooling or temperature stresses resulting from subcooling, the following measures can be taken, as described in... Fig. Figure 1 shows that the valve 1 has a region 16 in a first section or in the first housing part 2, in which a phase change material 17 is arranged. The region 16 can be formed by a wall of the first housing part 2, meaning that a wall of the first housing part 2 can form a cavity or housing cavity 18 which can be filled with the phase change material 17, or, as shown in Figure 1, Fig. Figure 1 shows the valve 1 in its finished state, filled with the phase change material 17. For filling and / or draining the phase change material 17, the wall of the first housing part 2, which forms the area 16 and encompasses the electronic circuit board 15, can have at least one opening. The opening can be non-destructively and reversibly opened and / or closed, for example, by means of a sealing screw, i.e., a screw which may have a seal. The phase change material 17 can be present in the housing cavity 18 in a liquid state at room temperature and / or before the valve 1 is operated. For example, it may be possible to fill the housing cavity 18 in a liquid state through the at least one opening.In other words, an additional layer of phase-change material 17 can be applied to a wall of the valve in area 16, particularly to a wall of the first housing part 2. During operation of the valve 1, the walls of the respective housing parts 2, 11, 6 can cool down against the longitudinal direction 14, or the temperature in the respective housing parts 2, 11, 6 can drop during operation. The phase-change material 17 can have a melting point of 5 degrees Celsius. If area 16 or the first housing part 2 cools down to 5 degrees, the phase-change material can transition from a first phase, here the liquid phase, for example, to a second phase, here the solid phase, for example. In this process, heat can be released in the form of the enthalpy of fusion or enthalpy of solidification and transferred to the first housing part 2, thereby indirectly heating the electronic circuit board 15 via this housing part 2.This can reduce or prevent thermal stresses or cooling of the electronic circuit board 15 during operation of the valve 1, compared to a valve without an additional layer. Alternatively, it can be provided that the in . Fig. Figure 1 shows an additional layer of phase-change material 17 arranged on the first housing part 2 by means of an element 19 forming an element cavity 20. The element cavity 20 of the element 19 can, for example, be completely enclosed by a protective layer 21, such as a metal sheet or plastic, and can be slid over or onto the valve 1 or the first housing part 2. The protective layer 21 can have at least one fluidically sealable opening on a side facing away from the wall of the first housing part 2 for filling and / or draining the phase-change material 17 from the element cavity 20.

[0044] Fig. Figure 2 shows a valve 1 for flow control of the refrigerant in the refrigerant circuit, with phase change material 17 arranged in a second section of the valve housing 1, wherein the second section may include the actuator 3. The area 16, which may be a second section of the valve housing 1, may be enclosed by the first housing part 2 or the second housing part 11. In the area 16 or the second section, the respective housing part 2, 11, i.e., either the first housing part 2 or the second housing part 11, may form a cavity or housing cavity 18 in which, particularly in the finished state of the valve, the phase change material 17 may be arranged. By virtue of the fact that the area 16 in Fig. 2 in relation to the longitudinal direction 14, compared with Fig. 1, before area 16 in Fig. If the valve 1 is arranged in a way that further delays the cooling of the electronic circuit board 15 when the valve 1 is operated, then the temperature of the valve 1, or of the housing or housing parts 2, 11, 6, drops when the valve is operated against the longitudinal direction 14, a phase change temperature, i.e., for example, a melting temperature of the phase change material 17, can be reached earlier than if the phase change material 17 were arranged further up (against the longitudinal direction 14) compared to an arrangement in Fig. 1.

[0045] Fig. Figure 3 shows a valve 1 for flow control of the refrigerant in the refrigerant circuit with phase change material 17 arranged in a shaft 5 designed as a hollow shaft. As in Fig. As shown in Figure 3, the shaft 5 for actuating the compensating piston can have the area 16 in which the phase change material 17 can be arranged. A wall of the hollow shaft 5 can seal the cavity in the hollow shaft fluidically at one end and have an opening at the other. The other end of the wall of the hollow shaft can, for example, have a thread to allow the cavity of the hollow shaft to be sealed fluidically after it has been filled with the phase change material 17, for example by means of a sealing screw. This allows the phase change material 17 to be retained in the cavity of the hollow shaft in the finished state of the valve 1 or when the valve 1 is assembled.

[0046] Additionally or alternatively, it can be provided that a connection area 16 exists between two housing parts, for example, between the first housing part 2 and the second housing part 11 and / or between the second housing part 11 and the third housing part 6, in which the phase-change material 17 is arranged. Across all examples, the housing parts 2, 11, and 6 can each be connected to each other, for example, by screwing them together in the connection area; that is, the first housing part 2 can be screwed to the second housing part 11, and the second housing part 11 can be screwed to the third housing part 6.To arrange the phase change material 17 between two housing parts, it can be provided that one or two housing parts to be connected each form a partially open cavity, preferably bounded by a wall of the respective housing part, which can be fluidically sealed when the respective housing parts are screwed together. The respective cavity can have at least one opening through which the cavity can be filled with phase change material 17 or through which this can be drained from the cavity.

[0047] Alternatively, it can be provided that an insulating layer, i.e. a material with a particularly low thermal conductivity such as rubber, is arranged between two interconnected housing parts, so that at least the interconnected housing parts are only in thermal contact indirectly via the insulating layer.

[0048] Fig. Figure 4 shows a schematic sectional view of a half-section through a valve 1 for flow control of the refrigerant of the refrigerant circuit with an element 19 arranged on a housing wall of the valve 1, which at least partially delimits an element cavity 20 with a protective layer 21 of the element 19, in which a phase change material 17 is arranged in a first phase. Fig. 4 can represent a partial section of the valve, for example without the supply connections 12. In the Fig. In the area shown in Figure 4, or the upper area (relative to the longitudinal direction 14, pointing from top to bottom), the valve 1 or the valve housing can be rotationally symmetrical with respect to a rotational symmetry axis 23. The element 19 can partially delimit the element cavity 20, wherein the element cavity 20 can be completely delimited in the state of the element 19 arranged on the valve 1, partly by the protective layer 21 and partly by the housing wall of the valve 1. As shown in Figure 4, the valve 1 or the valve housing can be rotationally symmetrical with respect to a rotational symmetry axis 23. The element 19 can partially delimit the element cavity 20, wherein the element cavity 20 can be completely delimited in the state of the element 19 arranged on the valve 1, partly by the protective layer 21 and partly by the housing wall of the valve 1. Fig. As shown in 4, the protective layer 21 can be located in an area that is in Fig. 4, with respect to the longitudinal direction 14, central area, partially delimit the element cavity 20 and form a fastening area 22 in one or two adjoining areas. In the fastening area 22, the element 19, or the protective layer 21, can be fastened to the housing wall of the valve 1. For this purpose, the fastening area 22 or the two areas in Fig. The mounting area 22, as shown in the four illustrations, has bores, and the housing wall in the area of ​​the mounting area 22 has corresponding bores, so that the element 19 can be fastened to the housing wall by means of screws. Additionally or alternatively, the mounting area 22 can be glued to the housing wall or non-destructively and reversibly clipped, for example, by means of retaining elements provided by the mounting area 22, which can be non-destructively and reversibly connected to locking lugs provided by the housing wall. Fig. 4. The phase change material 17 can be in a first phase, for example at room temperature, and operation of the valve 1 may be omitted or started immediately. Additionally or alternatively, the element 19 can be held in the mounting area 22 by hose clamps on the valve 1 or on the housing wall of the valve 1. The element 19 can be arranged completely around the valve 1, i.e., around the axis of rotation symmetry 23, on the valve 1 or on the housing wall. Alternatively, the element 19 can be arranged only partially around the axis of rotation symmetry 23 on the housing wall.A seal, for example in the form of a rubber layer, can be arranged circumferentially or partially (depending on whether the element 19 is arranged completely or only partially circumferentially) between the mounting area 22, or the area of ​​the protective layer 21 which forms the mounting area 22, and the housing wall. This prevents the phase change material 17 from leaking out, for example in the liquid state, or from escaping in the gaseous state from the element cavity 20.

[0049] Fig. 5 shows the valve from Fig. 4 during operation of valve 1. The phase change material 17 can, for example, have a melting point or solidification point of 5 degrees Celsius. In Fig. 5. The valve 1 may have been operating for so long that a predetermined temperature, which may be the solidification temperature, has been reached in the phase change material 17, at least in certain areas or sections. By at least partially reaching the solidification temperature in the phase change material 17, the phase change material 17 may have transitioned, or is about to transition, at least in certain areas from a first phase, for example, the liquid phase, to a second phase, for example, a solid phase. As indicated by arrow (24) in Fig. As indicated in section 5, the enthalpy of solidification 24 released in this process can be released to the valve housing wall or transferred to the housing wall. This can be done as shown in Fig. 4 and Fig. 5 along a particularly high temperature gradient or a particularly steep temperature gradient, because the phase change material 17, due to the fact that the protective layer 21 only limits part of the element cavity 20, is in direct contact with the housing wall. As a result of heat transfer of the enthalpy of solidification 24 from the phase change material 17 to the housing wall, cooling due to the operation of the valve 1 can be delayed in the area or the area in which the element 19 is arranged. The element 19, shown in Fig. 4 and Fig. 5, can have an opening for filling the element cavity 20, in particular in a state of the element 19 mounted on the valve 1, which can be closed non-destructively and reversibly in a fluidically tight manner and opened to allow fluid flow, or two such openings through which the element cavity 20 can be filled with the phase change material 17.

[0050] Alternatively, it can be provided that, prior to attaching the element 19 to the valve 1, the phase change material 17, fluidically sealed by, for example, a plastic layer or plastic film, for example in the form of a plastic bag, is arranged in the element cavity 20 and the element 19 is attached to the valve 21 after the plastic bag has been inserted.

[0051] Fig. Figure 6 shows a schematic sectional view of a half-section through a valve 1 for expanding the refrigerant of the refrigerant circuit. An element 19 is attached to a housing wall of the valve 1 by means of an adhesive layer 25. The element 19 has a protective layer 21 that completely encloses an element cavity 20, and a phase change material 17 is arranged in the element cavity 20 in a first phase. In this example, the valve 1 can be out of operation or in the process of starting or starting operation. The element 19 can have a protective layer 21 that completely encloses the element cavity 20 and in which the phase change material 17 is arranged. In this example, the phase change material 17 can, for example, be at room temperature (20 degrees Celsius). The protective layer 21 can, for example, be made of a plastic film. The protective layer 21 or the plastic film can fluidly enclose the phase change material 17. Fig. 6. The phase change material 17 can be present in a first phase, for example, in liquid form. The element 19 can have a side or area which, when the element 19 is attached to the valve 1, is to be brought into contact with the housing wall of the valve 1. This side can have the adhesive layer 25, at least partially, for attaching the element 19 to the valve 1.

[0052] In this example, element 19 can be flexible, i.e., movable or bendable, without the phase-change material 17 escaping from the element cavity 20. For this purpose, the protective layer 21 can be made of a flexible material such as elastic plastic. This offers the advantage that element 19, particularly in conjunction with the adhesive film or adhesive layer 25, can be wrapped around the valve 1 or the housing wall of the valve 1 and simultaneously bonded or fastened in place. Alternatively, element 19 or the protective layer 21 can be provided that it only partially confines the element cavity 20, whereby an area of ​​the element cavity 20 not confined by the protective layer 21 can be completely, i.e., fluidically sealed, by applying an adhesive film or the adhesive layer 25.

[0053] Fig. 7 shows that in Fig. 6. Element 19, designed as a so-called adhesive pad, during operation of the valve 1. During operation of the valve 1, the phase change material 17 may have cooled down, at least in some areas, to its solidification temperature, for example, 5 degrees Celsius. As in Fig. As shown in Figure 7, the enthalpy of solidification 24 released in this process can be transferred as heat to the housing wall of the valve, thereby heating it in the area which, for example, is partially enclosed by the element 19 or on which the element 19 is in contact.

[0054] Fig. Figure 8 shows a refrigerant circuit with valves used in several functions to operate the refrigerant circuit. Based on Fig.Section 8 is intended to describe, by way of example, the functions in which the valve can be used in a refrigerant circuit. The refrigerant circuit can include a gas cooler 26, a control unit 28 for controlling an actuator 3 of a valve, a main control unit 29, an evaporator 32, as well as a high-pressure valve 27, a gas bypass valve 30, an electric expansion valve 31, and an electric pressure regulator 33. The refrigerant circuit can, for example, be part of an air conditioning system in a motor vehicle.

[0055] Overall, the examples show how a valve with reduced icing function or tendency and a wider range of use can be provided.

Claims

[1] Valve (1) adjustable by means of an actuator (3) for controlling the flow rate of a refrigerant in a refrigerant circuit, the valve (1) comprising a housing, the actuator (3) by means of which a flow rate of refrigerant can be adjusted, and an electronic circuit board (15) for controlling the actuator (3), wherein the valve (1) has at least one area (16) in which a phase change material (17) is arranged, wherein the phase change material (17) is configured to perform a phase change from a first phase to a second phase by releasing latent heat when a predetermined temperature is undershot. [2] Valve (1) according to claim 1, wherein the at least one area (16) includes a first section of the housing by which the electronic circuit board (15) is enclosed. [3] Valve (1) according to one of the preceding claims, wherein the at least one area (16) includes a second section of the housing by which the actuator (3) is enclosed. [4] Valve (1) according to one of the preceding claims, wherein the actuator (3) has a shaft (5) which is designed to actuate a compensating piston (7) of the valve (1), whereby the flow rate is adjustable and the shaft (5) is designed as a hollow shaft and at least one area (16) includes a cavity inside the hollow shaft. [5] Valve (1) according to one of the preceding claims, wherein the at least one area (16) includes a connection area arranged between two housing parts of the housing and the two housing parts are each thermally connected to the connection area. [6] Element (19) for a valve (1) comprising an element cavity (20) at least partially bounded by a protective layer (21), into which a phase change material (17) can be filled, wherein the protective layer (21) forms a fastening area (22) of the element (19) by means of which the element (19) can be at least indirectly fastened to or in the valve (1). [7] Element (19) according to claim 6, wherein the protective layer (21) has at least one opening through which the phase change material (17) can be filled into the element cavity (20). [8] Element (19) according to one of claims 6 to 7, wherein the element cavity (20) is partially open, so that the phase change material (17) in the state of the element (19) being filled with it and attached to or in the valve (1) is in direct contact with a wall of the valve (1). [9] Element (19) according to claim 8, wherein the protective layer (21) has a seal on a side which, in the fixed state, is brought into contact with the wall. [10] Element (19) according to one of claims 6 to 7, wherein the element cavity (20) is completely enclosed by the protective layer (21) and the element (19) has an adhesive surface (25) by means of which the element can be bonded to a wall of the valve (1).

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