SE531780C2 - Device for distribution of an expanding liquid - Google Patents

Description

531? 8Ü 2 different properties. In this case, the channels in both sections must have different, but precise, flow rates.

Accurate distribution is difficult to achieve at low speeds because the two-phase flow tends to separate, resulting in the liquid portion settling at the inlet of the manifold while the gas portion is distributed to the remainder of the space. As a result, the liquid preferably flows into the first channels. Conversely, at high speeds, the inertia makes it difficult for the liquid to change direction and flow into the channels. As a result, most of the liquid refrigerant collects in the farthest part of the manifold and consequently flows into the channels located in this farthest part.

This process means that the cooling properties will vary between the different channels, which in turn leads to deteriorating cooling properties both in terms of capacity and homogeneity.

The distribution can be improved if the pressure drop across the ducts is higher than the pressure drop in the manifold. The larger this ratio is, the smaller the pressure drop difference between the different channels and the better the distribution.

The state of the art includes distributors located near the inlet of each (alternatively every other or every third) channel. Distributors usually comprise a fixed flow-limiting cross-section at the inlet of the duct, which gives a pressure drop before the duct but after the mixture is distributed along the length of the manifold, in contrast to the previously described situation where the main pressure drop occurs in the valve before distribution of the mixture. In this way, the pressure drop in the duct increases in relation to the pressure drop in the manifold. This solution solves part of the problem, but only in a static construction. The flow in the manifold still constitutes a two-phase mixture with the above process as a result.

SEP! TBÜ 3 A device for homogeneous expansion of a mass flow of two-phase coolant consisting of liquid and gas in a plate evaporator is described in US-A-5 806 586. The evaporator has a distribution channel which can be filled on the inlet side with the coolant mass flow flowing from an expansion valve.

The evaporator further has a plurality of heat exchanger sections which branch substantially perpendicularly from the distribution channel along the latter and at a certain distance from each other. To achieve a homogeneous distribution of the mass flow to the heat exchanger sections, a porous body is placed in the distribution channel. With this expansion valve, distribution is improved, but still remains far from ideal.

SUMMARY OF THE INVENTION The object of this invention is to eliminate or at least mitigate the above-mentioned disadvantages by providing a modern pressure reducing valve according to claim 1.

The ingenious valve enables expansion variation by varying the distance the coolant is transported, in contrast to ordinary valves where the expansion (or pressure drop) is determined by variations in the cross-section. The ingenious solution makes it possible to design efficient valves that eliminate or at least mitigate the disadvantages that apply to the state of the art.

With the ingenious valve, it is possible to maintain a liquid single-phase flow until the space distribution of the flow is affected in a relevant way.

In one or more embodiments, the pressure reducing valve comprises an inlet located in an inner cylinder, this inner cylinder being rotatably mounted in a cavity whose inner wall comprises the outlet, and where the channel is formed by a gap between the inner wall of the inner cylinder and said inner wall and wherein the rotation of the said inner cylinder varies the length of the channel, which is constituted by the distance between the inlet and the outlet. The use of an inner cylinder 531 FBÜ 4 and a rotational movement makes it possible to vary the shape of the channel and the function of the valve in an advantageous manner. The inner cylinder can be easily machined with standard equipment and can be fitted in the cavity with standard measures.

In one or more embodiments, the inner cylinder is hollow with openings arranged along the longitudinal axis of the cylinder, which flow join the interior of the cylinder with the channel.

This design facilitates the use of the valve as the inlet of the valve, and thereby its connecting pipe, can be arranged concentrically without any complicated construction. In addition, the distribution of the coolant can be carried out before said coolant flows out through the openings.

In one or more embodiments, the inner cylinder has an outer axially widened recess into which the openings open. The recess will function as a second distribution channel, which evens out the pressure difference and distributes the flow even better. A construction with a recess is also a simple way of obtaining homogeneous conditions for the different channels.

In one or more embodiments, the channel has a cross-section that varies when the length of the channel varies. This construction will result in an expansion that is not directly proportional to the length of the channel, i.e. rotation angle, to one and which enables the production of an expansion valve with exponential flow property, or any other desired flow property. In one or more further embodiments, the openings are essentially arranged in pairs, which are diametrically located on opposite sides of the axis of rotation of the inner cylinder. This makes it possible to equalize a bending force acting on the inner cylinder as a result of the pressure difference on opposite sides of said inner cylinder. In some constructions, this bending force can deform the transverse profile of the duct and thereby cause undesired variation in the expansion and / or flow rate in the coolant.

In one or more embodiments the inner wall has a projection extending into the channel, where the rotation of the inner cylinder varies a distance between a lug on said projection and the inner cylinder, which thus varies the cross-profile for a free passage in the channel, where consequently a pressure drop varies. In this embodiment, the variation in expansion is determined by the variation in the length of the channel.

Nevertheless, under certain operating conditions, the pressure drop in the free passage represents in practice the entire pressure drop in the valve.

In one or more embodiments, the valve comprises an assembly consisting of an inner cylinder and an outer cylinder, where said assembly can be installed in a cavity in a heat exchanger system. This design is particularly suitable for use in heat exchanger systems as all functional parts can be pre-assembled and then installed in the heat exchanger system without any precision work having to be performed on the heat exchanger system itself. Inlets, ducts and outlets, which determine the properties of the valve, can all be pre-assembled.

In one or more embodiments the valve is an assembly of a fixed part and a part which can rotate about an axis of rotation, said valve having a longitudinal dimension, L, along the direction of the axis of rotation, and where at least one of said parts is constructed of separate and combinable - raw elements with a length l, where l <L. The use of structural parts with fixed lengths increases the standardization of the system in such a way that identical structural parts can be used in different applications, e.g. the total length of the valve can be easily increased by adding one or more elements. When the valve is constructed of smaller elements, other types of machining techniques can be used.

In one or more embodiments, the valve is installed in a heat exchanger system which includes a circuit comprising 531? BÛ 6 comprising a condenser, an evaporator consisting of a manifold which is flow-connected with several liquid channels which are connected in parallel, and a compressor , where all units have an inlet and an outlet, and where the condenser outlet is connected to the valve inlet, the valve outlet is connected to the evaporator inlet, the evaporator outlet is connected to the compressor inlet, and where the compressor outlet is connected to the condenser. the inlet of the condenser, in such a way that the valve is mounted in or constitutes the distribution pipe.

An ingenious concept relates to a plate heat exchanger which comprises a valve in accordance with the invention. The plate heat exchanger comprises at least one base plate and one pressure plate, the pressure plate having an inner recess where one end of the valve can be mounted in accordance with the invention.

The recess makes it possible to mount the inner end of the valve without additional parts. The recess has a substantially circular bottom part and is dimensioned to provide space at a part of the end of said valve. As a further advantage, the recess can also function as a barrier in the axial direction, so that in cases where, for example, the valve consists of an assembly of several elements, the recess can function as a support surface which helps to hold the assembly together. The manufacture of the recess is cost-effective and can easily be incorporated into a manufacturing process. In an alternative embodiment, a recess is provided in the form of a separate plate which can be mounted on the inside or outside of an end plate or a pressure plate.

Brief Description of the Drawings Adequate embodiments of the invention will be described in detail in the following, with reference to the accompanying figures, in which Fig. 1 shows a schematic representation of a basic cooling cycle. Fig. 2 shows a partial schematic representation of a plate heat exchanger in accordance with the prior art.

Fig. 3 shows a schematic representation of a plate heat exchanger in accordance with Fig. 2, provided with a main expansion valve.

Fig. 4 shows a schematic representation of a plate heat exchanger in accordance with Fig. 2, provided with individual expansion valves for each channel.

Fig. 5-7 show schematic representations of a plate heat exchanger in accordance with Fig. 2, provided with individual fixed flow restrictors for each channel and a main expansion valve.

Fig. 8 is a transverse profile in a radial direction of a valve in accordance with a first embodiment of the invention.

Fig. 9 illustrates various examples of cross-sections, in the axial direction, which are possible for the different embodiments of the invention.

Fig. 10 is a cross-section, similar to Fig. 8, of a valve in accordance with a second embodiment of the invention.

Fig. 11 is a cross-section, similar to Fig. 8, of a valve in accordance with a third embodiment of the invention.

Fig. 12 is a cross-section, similar to Fig. 8, of a valve in accordance with a fourth embodiment of the invention.

Fig. 13 is a schematic exploded view of an ingenious valve in accordance with a fifth embodiment of the invention.

Fig. 14 illustrates how the valve in one or more embodiments can be easily mounted with elements.

Fig. 15 is an exploded view of a valve in accordance with the ingenious concept mounted in a plate heat exchanger.

Fig. 16 shows a cross section of a plate heat exchanger in accordance with an ingenious concept. Detailed description of the embodiments of the invention The basic cooling cycle according to the prior art is shown in Fig. 1. The actual use of the cycle can of course be applied in an air conditioning device / system, a heat pump as well as in a actual refrigeration system / plant or any other process in which refrigerant is evaporated, kel. for example In the condenser 1, the gaseous high pressure refrigerant condenses. The condensed coolant then flows to the expansion valve 2. In the expansion valve 2, the liquid coolant passes a flow-limiting cross-section. This causes a high pressure drop, where the pressure drops to a value close to the evaporation pressure. In the process, part of the liquid refrigerant evaporates and the mixture is cooled to a temperature close to the evaporation temperature. Via the valve outlet, a cold two-phase mixture leaves the valve 2. The two-phase mixture flows into the evaporator 3 where the cold liquid coolant evaporates and cools down a liquid medium. There are a number of commonly occurring liquid media, e.g. salt-soluble, etc. The cold gaseous low-pressure refrigerant then flows into the compressor 4. Here, the refrigerant pressure increases to a level that is high enough for the intended refrigerant to be able to condense in the condenser 1.

Control of the valve 2 in conjunction with the evaporator 3 is central to an adequate function in the cycle. Consequently, when the cooling demand changes, the valve must be adjusted. air, water, If too much coolant leaves the valve, there is a risk that the liquid will not evaporate completely in the ducts.

This causes liquid to leave the evaporator, which in some cases can damage the compressor. If too little coolant leaves the valve 2, the required capacity cannot be maintained.

In a plate heat exchanger, number of parallel channels 6, see Pig. 2, which consists of one, it may be difficult to obtain an exact liquid distribution from a distribution pipe 5 to the parallel channels 6 and then to a collecting pipe 7. The distribution pipe 5, or "collecting pipe", is a branch pipe for distribution from which the channels 6 branch off. In Fig. 2 only the flow pattern is illustrated, the heat exchanger itself is indicated only as separate surfaces 8. It can be composed of different types of parallel interconnected channels.

Assume that the pressure drop between A - B and C - D is large in relation to A - D and B - C. Since the pressure drop must be uniform from the inlet to the outlet regardless of whether the liquid follows the path A - D or A - B - C - D, consequently, this means that the pressure drop is higher between A - D than between B - C. Since the pressure drop constitutes the driving force of the flow, it consequently means that the flow of the coolant will differ between the different channels.

A correct distribution is even more difficult with a two-phase flow, e.g. for an evaporator in a cooling device / plant. Fig. 3 shows an assembly with valve and evaporator. Saturated or almost saturated coolant flows in through valve 2 under high pressure, usually close to the condensing pressure. In the valve 2 it expands to a pressure which just exceeds the evaporation pressure whereupon a part of the liquid evaporates. The resulting two-phase liquid has a large volume, which increases the pressure drop in the manifold, which therefore constitutes the problem. If the speed of the coolant is low in the manifold 5, the liquid part settles at the inlet part of the manifold 5 and preferably flows into the first channels, which branch off from that part of the manifold 5. If the speed of the coolant is very high, the inertia the refrigerant has difficulty changing direction and flowing into the ducts. In this case, coolant accumulates in the farthest part of the manifold 5 and consequently flows into the farthest channels 6. Consequently, the flow rate of the coolant in the manifold 5 is a parameter which affects the performance of the plate heat exchanger in an undesirable manner. 531 YBÜ Both problems can be solved by the liquid expansion taking place just before each channel 6. In Fig. 4 a number of adjustable flow limiters 2 'are placed before each channel 6. In the distribution pipe 5 there is now only liquid, which solves the problem of phase separation. , which in turn means that the pressure drop between A - B is applied. The pressure drop between C-D is still comparatively low, while the pressure drop between A-A'-D and B-B'-C is high, in practice corresponding to the pressure difference between the condensing pressure and the evaporating pressure. The flow of the coolant through the different channels will be exact, since an exact amount of coolant passes the respective adjustable flow limiter 2 '. Consequently, there is no distribution problem because there is only liquid refrigerant and no gaseous refrigerant in the manifold 5. The solution of using a plurality of small, known type is expensive, adjustable flow restrictors of one and to actually integrate the individual valves in the evaporator 3. is troublesome. Furthermore, maintenance and cleaning of these valves or flow restrictors is a complicated task.

A practical solution is to keep the main expansion valve 2 and to introduce fixed flow restrictors 9,, ll instead of adjustable flow restrictors 2 ', in accordance with Figs. 5-7. The fixed flow restrictors 9-11 may consist of a conduit with fixed flow restrictors 9 in the peripheral wall, where said conduit is inserted in the distribution pipe 5, see Fig. 5. In a plate heat exchanger the plates can be formed into plate-like flow restrictors 10, see each channel inlet. 6, alternatively discs with drilled flow restrictors ll can be inserted into an opening for each channel, see Fig. 7. If the fixed flow restrictors 9-ll were allowed to carry the entire pressure difference, these will distribute the coolant in an adequate manner. Nevertheless, in order to function at partial load, the valve 2 must effect the necessary pressure drop so that the flow in the ducts can be varied, which means that the greater the pressure drop, the more the above-mentioned problem of double phase flow will occur. . Furthermore, the optimal size for the flow restrictors 9-11 varies with the nominal capacity, pressure, coolant type, etc., which means that each cooling system must be provided with individually tailored flow restrictors. Consequently, the use of fixed flow restrictors in the above-mentioned context becomes an inflexible solution.

The invention alleviates the above-mentioned problems and a first embodiment of the present invention is described below with reference to Figs. 8 and 9. This embodiment solves the practical problems with the occurrence of a two-phase flow. The valve 100 consists of two concentric tubes 101, 102. for example a brass alloy, bronze alloy or stainless steel, but can of course also be made of other materials. The tubes are preferably made of metal, e.g. Inner PTFE (polytetrafluoroethylene), etc. the tube 101 has an outer thread profile and the outer tube 102 has a matching inner thread profile, which ensures a safe and repeatable fit between the tubes 101 and 102.

The back axes of these threads have a truncated cone shape so that specific channels are formed between the inner and outer tube. The cylindrical recesses 108, starting at the recess / recess 110, continue along the circumference and cease just before they reach the recess / recess 110 again. The recesses 108 can have a rectangular, V-shaped, hemispherical or other suitable transverse profile, in accordance with Fig. 9. The recesses can be manufactured individually in the form of cylindrical back axles, or as screw threads.

The outer tube 102 may be provided with inner recesses 111 in accordance with the above description which should preferably be smooth, for cost reasons. If the outer tube is provided with inner recesses 111, the recesses in the two tubes 101 and 102 should be made in the form of threads so that the inner cylinder 101 is screwed into the outer cylinder 102. The outer circumference of the inner tube can also be made smooth, so that the channel 108 is essentially of a gap between the inner tube and the outer tube. 535 TBÛ 12 Furthermore, the inner tube 101 has an inlet, not shown, which leads to its hollow interior 112. Coolant flowing in through the inlet is distributed along the axial direction of the hollow interior 112, where the interior acts as a manifold. The coolant then follows the path indicated by arrow 114 in Pig. 8, the openings 104 in the inner cylinder 101, circularly along the gaps / channels 108 ("channels" hereinafter) between the inner cylinder 101 and the outer cylinder 102 to then flow out of the valve 100 through the outlets 108 in the outer radially out through the cylinder 102. When the coolant flows through the openings 104 in the inner tube 101, through the channels 108 and out through the holes 106 in the outer tube 102, a pressure drop occurs.The dimensions of the channels 108 are determined so that the pressure drop from condensing pressure to evaporation pressure takes place along said channels 108. As previously pointed out, Depending on the type of coolant, which is one of the reasons why the valve assembly is adjustable.When the pressure decreases as a result of the pressure drop, the liquid starts to boil and results in a two-phase mixture of gaseous and liquid coolant flowing out of the openings 106 in the outer tube 102.

The length of the flow path from the openings 104 in the inner tube 101, through the channels 108 and out through the holes 106 in the outer tube 102, is varied by rotating the inner tube 101 so that the circumferential distance between the openings 104 and the heel 106 varies. When the flow path is varied, the pressure drop and consequently also the flow through the valve 100 is also varied. A physical lug 107 prevents the coolant from following an alternative flow path along the circumference of the channels 108. In Pig. 10, the lug 107 is integrated with the inner tube 101, the lug 107 corresponding to a part of the inner tube 101 having an outer diameter corresponding to the inner diameter of the outer tube 102. Accordingly, said physical lug 107 allows the coolant to flow only along a flow path / direction through the channels 108. The coolant flowing through the channels 108 is given a specific flow direction. This can lead to the occurrence of a relative torque between the two tubes 101 and 102.

In addition, the refrigerant will flow into the channels 108 under relatively high pressure and flow out of the channels 108 under a relatively lower pressure. This can result in an oblique load and thereby asymmetric control characteristics. If such asymmetries are considered a problem, they can be remedied with more elaborate constructions, in accordance with the following description. In the design shown in Fig. 8, the oblique load forces do not take and to improve the control capacity of the valve 100, ball bearings (not shown) can be placed between the inner tube 101 and the outer tube 102. The ball bearings are placed in a notch near each end of at least one of the pipes.

Note that the number of openings 104, channels 108 and outlets 106 need not always be the same in number.

Furthermore, when the valve 100 is used in an evaporator in a plate heat exchanger system, the number of outlets 106 does not have to correspond to the number of evaporation channels in order to achieve a mutually adequate distribution. An outlet 106 per two or three evaporation channels is usually sufficient. The openings 104 and the outlets 106 are usually round, to simplify the manufacture, but they can just as easily be designed as slits, for rectangles, etc.

Fig. 10a illustrates a valve 100 in accordance with a second embodiment. In this embodiment, the openings 104 leading from the interior 112 of the inner cylinder are diametrically located on opposite sides of an axis of rotation R. In this way, the inner cylinder 101 is balanced and no bending forces occur on its longitudinal axis. Furthermore, as shown in Fig. 10a, the channels 108 need not have the same height along the length of the channel. By allowing the height of the channel to increase as its length decreases through the rotation of the inner cylinder 100, the flow change can become quite proportional to the total flow for a given change in the length of the channel. This means that a valve 100 with logarithmic characteristics has been obtained. There are, of course, countless possible variants of this second embodiment.

Common to these is that the control area, the possibility of regulating the pressure drop, on the duct, becomes larger than if a specific height or specific cross-profile for the same is used.

A variant of the second embodiment is shown in Fig. 10b.

Here, the outer circumference of the inner cylinder has an oval cross-section, e.g. defined by two interconnected semicircles, which form a channel of varying height along the length of the channel. The inner cylinder abuts the outer cylinder at two diametrically opposite positions where the radii of the inner cylinder are greatest. The openings 104 in this embodiment are located at two diametrically opposite positions where the radii of the inner cylinder are at least. This results in a balanced valve assembly.

A third embodiment of the invention is illustrated in Fig. 11. In relation to the embodiment in Fig. The tile 100 in Fig. 11 is balanced with respect to the bending forces acting on the inner tube 101 due to pressure differences. Furthermore, in operation, the flow follows the path indicated by the lines and arrows 114, making the flow perfectly symmetrical, as shown in Fig. 11.

This also balances any torque caused by the coolant flow. Note that the outer tube has diametrically opposite outlets. Since there are two sets of outlets, a third pipe (not shown) can be mounted as an external enclosure around the outer pipe. This enclosure comprises only a set of outlets, said outlets being suitably located in accordance with the intended use of the valve 100. The use of an external enclosure is also applicable to the second embodiment, as well as the first, if desired.

A fourth embodiment of the invention is illustrated in Fig. 12. This embodiment is reminiscent of the second embodiment, but where the majority of each channel 108 has a significant cross-section, which means that these do not cause a significant pressure drop. The outer tube 102 nevertheless has a projection 116 extending into each channel 108 (as before, there only needs to be one channel), which in this way creates a flow restriction. Furthermore, the inner tube 101 has a varying diameter, so that the rotation of the inner tube 101 not only changes the length of the channel 108, in accordance with the previous description, but also causes the transverse profile of the flow restriction to vary. Most of the expansion will in this way take place at the flow restrictor, which forms part of the channel.

A fifth embodiment is shown in Figs. 13a and b. In this embodiment, the height, or transverse profile, of the channel 108 varies between the inner tube 101 and the outer tube 102, in the same way as in the second embodiment. In this fifth embodiment, however, the inner tube 101 is arranged so that it "rolls" along the inner circumference of the outer tube 102 when the inner tube 101 rotates. This can be a way to reduce wear and thereby make the construction more durable. Fig. 13a shows a closed position and Fig. Position. Fig. 13b shows a partially open. Variants of a sixth embodiment are illustrated in Fig. 14. This embodiment comprises all other embodiments as it illustrates an alternative construction which can be applied to all embodiments. In this sixth embodiment the structure of the inner tube resembles the inner tubes which described in other embodiments, preferably a cylinder with a smooth outer circumference. The outer tube 102 differs in nature by being assembled from separate parts. rings 102 '. The use of separate rings 102 'enables the use of alternative materials and manufacturing methods. In this embodiment, the inner tube 101 is as previously made of metal while the rings 102 'are made of extruded polytetrafluoroethylene (PTFE). PTFE also has the advantage that it acts as its own lubricant, which means that the rings function as their own shaft bearings, which eliminates the need for outer shaft bearings. 14 il- and where Fig. Illustrates three different embodiments of said rings, 531? BÛ 16 the far right has been provided with reference numbers.

Fig. 14 shows, from top to bottom, an axial cross-section, a radial cross-sectional view and a perspective view, where the different embodiments are illustrated from left to right in each view. It is worth noting that the outer encapsulation 118 is shown in Fig. 14. For the sake of clarity, it should be pointed out that the object marked with 108 in the Vy, lower part of Fig. 14 corresponds to a cut-out in the inner part of the outer tube element l02 '. Once the valve is assembled, this cutout forms the channel 108, hence the reference.

When the valve assembly 100 is mounted in the manifold 5 or the inlet of a plate heat exchanger, the outer tube is mounted, or when the outer enclosure 118 is applied, so that it is stationary with respect to the inlet / plates while the inner tube 101 is simultaneously rotatable.

The valve 100 can also be combined with a heat exchanger system which includes a circuit comprising a condenser, a pressure control option, an evaporator consisting of a manifold where the valve is mounted with a flow connection to several liquid channels which are connected in parallel, and a compressor, where all units have an inlet and an outlet. The condenser outlet is connected to the valve inlet, the valve outlet is connected to the evaporator inlet, the evaporator outlet is connected to the compressor inlet, and where the compressor outlet is connected to the condenser inlet. Said circuit comprises a coolant which is prevented from boiling until it has passed the valve by any of the following methods: lowering the temperature of the coolant downstream of the condenser and upstream of the valve, and changing the coolant pressure by a method which increases the coolant pressure downstream of the condenser.

The temperature is preferably lowered by using a pre-cooler, and the pressure is preferably changed with a pump. According to the invention, the valve can also be operated by a traditional expansion valve which is placed between the valve and the condenser in the circuit. Although the valve in accordance with the invention can be used as a stand-alone unit, the described arrangement makes it possible to adjust the ingenious valve to a suitable setting during the start-up of a heat exchanger device / system, so that it can thereby adapted to specific capacity ranges, coolants, ambient temperatures and so on. The daily fine-tuning of the capacity can then be handled with other methods, colds, e.g. variable pressure and further expansion before the ingenious valve. By using the valve in this context, it is possible to increase the usability of existing heat exchanger systems.

Fig. 15 shows an exploded view of a complete assembly of a valve according to one of the embodiments, when mounted in a plate heat exchanger 128. A housing 120 has an inlet opening 130 through which the coolant flows (indicated by the arrow). The housing further comprises mechanisms for drive and power transmission, stepper motor 132. The outer cylinder 102 provides 134, exemplified by one fitted with shaft- e.g. ball bearings, roller bearings, etc. to make the inner cylinder 101 rotatable. The housing 120 is sealed against a support sleeve 136 on the heat exchanger 128, by welding thread cutting, etc. The drive shaft 137 of the motor 132 is connected to a shaft 138 suspended in the inner cylinder 101 so that the motor 120 can drive the rotation of the inner cylinder 101.

Arrows 140 indicate the path of refrigerant flow into the housing 120 and out of the outer cylinder 102. Of course, the bearing surface between the inner cylinder and the outer cylinder must be sealed for incoming flow, to prevent leakage to or from the outer channel. Note further that this seal does not have to be perfect as long as the preferred flow path flows in through the inlet, through the outlets. through the ducts and out Fig. 16 shows a cross-section of a plate heat exchanger 128 which is adapted to fit a valve in a 531 TBC! 18 similarity with the ingenious concept. The heat exchanger 128 includes a base plate 142, a pressure plate 144 and a support sleeve 136 into which the valve is pushed in and over which the valve assembly is mounted. The pressure plate 144 includes a recess 146 which is adapted to accommodate and retain one end of the valve. The use of the recess is a reliable and cost-effective method of mounting the valve in the heat exchanger. It is likely that this use of a recess is also suitable for fitting other valve types. In an alternative embodiment, a recess can be provided in the form of a separate plate which can be mounted on the inside or outside of the pressure plate.

Those skilled in the art will appreciate that there are several materials which can be used to make the ingenious unit or components thereof, brass, e.g. machined extruded aluminum, PTFE and so on.

Claims (14)

10 15 20 25 30 35 531? BÜ 19 PATENTKRAV A pressure reducing valve for expanding a coolant, said valve comprising an inlet (104) (106) for outflow of a resulting expanded mixture of liquid and gas, (108) for inflow of said coolant, and an outlet and a channel flow-connected with the inlet and the outlets, characterized in that the length of said channel (108) obtains a specific degree of expansion and where the inlet is located in an inner cylinder (101), the inner cylinder (101) is rotatably mounted in a cavity whose inner wall comprises the outlet (106), ( 108) formed by a gap between the inner cylinder can be varied to (104) where this and where the channel (101) peripheral wall and said inner wall and where said inner cylinder (101) (198) constitutes the distance between the inlet (104) (106) . rotation varies the length of the channel, and the outlet The valve according to claim 1, (104) are arranged along the longitudinal axis of the cylinder (101), which connect the interior of the cylinder (101) to the channel (108). where the inner cylinder (101) is hollow and where openings The valve according to claim 1 or 2, wherein the inner cylinder (101) has an outer axially widened recess (108) into which the openings (104) open. The valve according to any one of the preceding claims, wherein the channel (108) has a cross-section that varies as the length of the channel (108) varies. The valve according to claim 4, for the channel (108) where the transverse profile is tapered towards the outlets. 10 15 20 25 30 35 531 780 20 The valve according to any one of claims 2-5, wherein the openings (104) are substantially arranged in pairs, which are diametrically located on opposite sides of the axis of rotation of the inner cylinder (101). The valve according to any of 1-6, the inner wall having a projection (116) the channel (108), the inner cylinder (101) having a distance between a lug on said projection where said extending into rotation varies (116) the inner cylinder (101), thus varying the cross-section of a free passage in the channel (108), where consequently a pressure drop varies. and The valve according to any preceding claim, wherein the valve comprises an assembly consisting of an inner cylinder (101) and an outer cylinder (102), said assembly being installed in a cavity in a heat exchanger system (128). The valve according to any one of the preceding claims, wherein the valve is an assembly of a fixed part and a part which can rotate about an axis of rotation, wherein said valve has a longitudinal dimension, L, along the direction of the axis of rotation, and where at least one of said the parts are constructed of separate and combinable elements (118) a length l, where l <L. with The valve according to any one of the preceding claims, wherein the valve is installed in a heat exchanger system comprising a circuit comprising a condenser, an evaporator consisting of a manifold connected to several liquid channels which are connected in parallel, a compressor (4), each of which has an inlet and an outlet, and where the outlet of the condenser (1) is connected to the inlet of the valve, the outlet of the valve is connected to the inlet of the evaporator (3), the outlet of the evaporator (3) is connected to the compressor (4) inlet, and where the outlet of the compressor (4) is connected to the inlet of the condenser (1), so that the valve is mounted in or constitutes the distribution pipe. A plate heat exchanger comprising a valve according to any one of the preceding claims. A plate heat exchanger comprising a plate having an inner recess (146) end of a valve according to any preceding claim. (144) for mounting one The plate heat exchanger according to claim 12, wherein the plate (144) is a pressure plate. The plate heat exchanger according to claim 12 or 13, wherein the recess has a substantially circular bottom portion and is dimensioned to accommodate a portion of said valve end.