Double-acting backwash valve with linked valve body

Abstract

A valve assembly for communicating with first, second, and third fluid regions, the valve assembly configured to passively switch between first and second modes of operation. The valve assembly comprises: a first valve (30) closing a first flow path (36) between the first fluid region and the second fluid region in a first mode of operation; and a second valve (40), which is open, providing a second flow path (46) between the second fluid region and the third fluid region. A functional connection (50) is provided between the first valve and the second valve such that a movement of the first valve body (31) into the closed position moves the second valve body (41) into the open position and vice versa. In the first operation mode, the second flow path between the second fluid area and the third fluid area is opened; and in a second operating mode, when the pressure of the fluid in the first fluid region overcomes the closing force of the elastic element (34) and the pressure of the fluid in the second fluid region, the first valve is opened while the second valve is closed, so that the first flow path between the first fluid region and the second fluid region is opened and the second flow path is closed; and the third fluid area is isolated.

Description

Technical Field

[0001] The present invention relates to passively switched valves that change valve state based on fluid flow. In a particular application, the present invention relates to an improved valve for use with thermal energy systems that passively backwash heat exchangers or other system components. Background Art

[0002] The inventors have previously developed backwash valve assemblies for heat exchangers, as shown in US Pat. Nos. 7,823,628, 7,171,972, and 6,827,091. These backwash valve assemblies have proven successful in passively backwashing heat exchangers to remove and / or reduce fouling.

[0003] However, improvements are needed in both functionality and application. Summary of the Invention

[0004] In one aspect, the present disclosure relates to a valve assembly for communicating with a first fluid region, a second fluid region, and a third fluid region, the valve assembly being configured to passively switch between a first operating mode and a second operating mode. The valve assembly comprises: a first valve body biased by an elastic element to a closed position against a first valve seat to close a first flow path between the first fluid region and the second fluid region in the first operating mode; and a second valve body acting on a second valve seat. In the first operating mode, the second valve body is in an open position spaced apart from the second valve seat, providing a second flow path between the second fluid region and the third fluid region. A functional connection is provided between the second valve body and the first valve body such that movement of the first valve body to the closed position causes the second valve body to move to the open position, and movement of the first valve body to the open position causes the second valve body to move to the closed position. In the first operating mode, the second valve body is in an open position spaced apart from the second valve seat, opening a second flow path between the second fluid area and the third fluid area, and in the second operating mode, when the fluid pressure in the first fluid area overcomes the closing force of the elastic element and any pressure of the fluid in the second fluid area, the first valve body can be moved to the open position, while at the same time moving the second valve body to a closed position against the second valve seat, so that the first flow path between the first fluid area and the second fluid area is opened and the second flow path is closed, isolating the third fluid area from the first fluid area and the second fluid area.

[0005] The assembly has particular application as a backwash valve assembly for thermal systems and is particularly useful for backwashing heat exchangers when main water is connected to the first fluid zone, as it provides active switching between different flow paths in a passively activated manner based on the pressure differential generated during normal operation.

[0006] In a preferred arrangement, the valve assembly is configured to return to the first operating mode when the spring force and any pressure in the second fluid region overcomes the fluid pressure in the first fluid region.

[0007] Preferably, the elastic element is a spring. The elastic element can be a separate metal coil spring, an elastic arm, or a restoring force generated by hydraulic or magnetic force.

[0008] Preferably, the functional connection is a mechanical linkage, a magnetic coupling or a hydraulic or pneumatic connection.

[0009] In one embodiment, the valve assembly includes its own fitting, and the first valve seat and the second valve seat are located within the fitting. The first fluid region is located on a first side of the first valve seat, the second fluid region is located on a second side of the first valve seat opposite the first fluid region and on the first side of the second valve seat, and the third fluid region is located on a second side of the second valve seat opposite the second fluid region.

[0010] Here, the fitting preferably includes integrated fittings or connectors at the first, second, and third fluid regions to allow the valve assembly to be connected to the thermal system, for example, via piping. These fittings or connectors can be internal or external connection surfaces that can be smooth (for welding or brazing connections, etc.) or threaded. Other types of clamping, gluing, welding, or any other suitable connection can also be used.

[0011] In a preferred arrangement, one or both of the first valve seat and the second valve seat are integrally formed in the fitting body. An elastic element support is preferably further provided in the fitting body, and the elastic element is provided between the elastic element support and the first valve body.

[0012] The fitting may be T-shaped, and the first valve seat and the second valve seat are preferably located along the same axis in a main channel passing through the T-shaped piece. A transverse channel of the T-shaped piece intersects the main channel at a position between the first valve seat and the second valve seat.

[0013] In another embodiment, the first valve seat and the second valve seat may be formed separately and then inserted into the mating body.

[0014] Here, a first valve housing is provided, in which the first valve seat is formed; and a second valve housing is provided, in which the second valve seat is formed. The first valve body is located within the first valve housing, while the second valve body is located within the second valve housing. The first and second valve housings can be inserted into the matching body. This arrangement with the first and second valve housings simplifies the requirements for the matching body, which can be formed as a T-shaped matching piece.

[0015] In order to allow simpler handling during assembly and to reduce loose parts, the elastic element may be located within the first valve housing and preferably preassembled within the first valve housing.

[0016] In a preferred arrangement, the rod or connecting rod extends preferably linearly between the first valve body and the second valve body.

[0017] To allow adaptation to various applications, in a preferred arrangement the length of the rod is adjustable.

[0018] In a preferred arrangement, a first seal is provided between the first valve housing and the channel wall of the fitting body, and a second seal is provided between the second valve housing and the channel wall of the fitting body. The seals may be O-ring seals or formed of any suitable sealing material.

[0019] In one embodiment, the first valve seat is disposed in a first valve housing that is insertable into a mating body, while the second valve seat is integrally formed in the mating body. In this embodiment, the first valve housing may include an outer shoulder that rests against a corresponding shoulder formed in the mating body. The first valve housing may include an axial support for a connecting rod or link for connection to the second valve body and may also include an elastic element. The first valve housing, the first and second valve bodies, the elastic element, and the connecting rod or link may be preassembled to simplify handling during assembly with the mating body.

[0020] In another aspect, a method of passively backwashing a flow component (such as a heat exchanger or other component of a thermal energy system) is provided, the method comprising:

[0021] A valve assembly for communicating with a first fluid region, a second fluid region, and a third fluid region is provided, the valve assembly being configured to passively switch between a first operating mode and a second operating mode, the valve assembly comprising: a first valve body biased by a resilient element to a closed position against a first valve seat to close a first flow path between the first fluid region and the second fluid region in the first operating mode; a second valve body acting on a second valve seat, the second valve body being in an open position spaced from the second valve seat in the first operating mode to provide a second flow path between the second fluid region and the third fluid region; and a functional connection between the second valve body and the first valve body such that movement of the first valve body to the closed position causes the second valve body to move to the open position, and movement of the first valve body to the open position causes the second valve body to move to the closed position;

[0022] connecting the first fluid zone to a main water supply or a source of pressurized fluid;

[0023] connecting the second fluid region to an inlet side of the flow component, which in one embodiment is a cooler side or inlet side of a heat exchanger of the thermal energy system;

[0024] connecting the third fluid region to an outlet side of the flow component, which in one embodiment is a warmer side or outlet side of a heat exchanger of the thermal energy system;

[0025] In the first operating mode, maintaining the second valve body in an open position spaced apart from the second valve seat provides a second flow path between the second fluid region and the third fluid region to allow flow from the cooler side or inlet side to the hotter side or outlet side through the second flow path in a first direction by convection or other means (e.g., when the fluid on the cooler side is heated or otherwise induced to flow in that direction); and

[0026] In the second operating mode, when the pressure of the fluid from the main water supply or other pressurized fluid source in the first fluid area overcomes the closing force of the elastic element and any pressure of the fluid in the second fluid area, the first valve body is moved to the open position, and the second valve body is simultaneously moved to the closed position against the second valve seat, so that the first flow path is opened and the second flow path is closed between the first fluid area and the second fluid area, isolating the third fluid area from the first and second fluid areas, and providing a flow of fluid from the main water supply or other pressurized fluid source in the second fluid area along a second direction opposite to the first direction.

[0027] The method may further comprise:

[0028] The valve assembly is inserted into a fitting defining the first, second, and third regions.

[0029] Here, the method may include integrally forming the first valve seat and the second valve seat in the fitting body. Alternatively, as mentioned above, the first valve seat and the second valve seat may be formed in separate first and second valve housings.

[0030] In a preferred arrangement, the functional connection is provided as a mechanical linkage, a magnetic coupling or a hydraulic or pneumatic connection.

[0031] Furthermore, it is preferred that the first valve body and the second valve body are aligned along a common axis.

[0032] The above features may be used alone or provided in various combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Further advantages and features of the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings, in which:

[0034] Figure 1 is a schematic diagram illustrating a double-acting valve assembly according to the present invention, which can be used for flow reversal based on a pressure differential, shown in a first operating mode, wherein the first valve is closed and the second valve is open to allow flow in a forward flow direction between second and third ports or areas of the valve assembly.

[0035] Figure 2 is similar to Figure 1 A schematic diagram illustrating a double-acting valve assembly for flow reversal is shown in a second operating mode wherein a first valve is open and a second valve is closed, allowing reverse flow caused by fluid entering a first port or region and exiting a second port or region.

[0036] Figure 3 is a cross-sectional view of another embodiment of a valve assembly including a double-acting valve assembly shown in a first operating mode, wherein a first valve is closed and a second valve is open, allowing flow between second and third fluid regions.

[0037] Figure 4 is similar to Figure 3 1 is a cross-sectional view of a double-acting valve, shown in a second operating mode, wherein the second valve is closed and the first valve is open, such that fluid can flow from the first fluid region into the second region, while the third region is isolated.

[0038] Figure 5A and Figure 5B yes Figure 3 and Figure 4 Additional views of the double-acting valve assembly shown in , showing additional details of the spring support.

[0039] Figure 6 is shown installed in the fitting Figure 3 Cross-sectional view of a double-acting valve assembly, where the double-acting valve assembly is shown in a first operating mode.

[0040] Figure 7 is similar to Figure 6 View of a double-acting valve assembly, shown in a second operating mode.

[0041] Figure 8A and 8B A schematic diagram of another embodiment of a double-acting valve assembly is shown in cross section, which is configured to be inserted into an existing piping component (such as a pipe or a T-piece), and includes a first valve housing and a second valve housing, with a first valve body and a second valve body and a valve seat respectively located therein.

[0042] Figure 9A and Figure 9B shows the first operating mode Figure 8A and Figure 8B A double-acting valve assembly wherein a separate spacer is located between the first valve housing and the second valve housing.

[0043] Figure 10A and Figure 10B Shows something like Figure 8A and Figure 8B A double-acting valve assembly wherein an integrated spacer is connected between a first valve housing and a second valve housing.

[0044] Figure 11 yes Figure 8A and Figure 8B A view of an alternative embodiment of a double-acting valve assembly is shown in FIG, wherein the connecting rod between the first valve body and the second valve body is adjustable.

[0045] Figure 12 yes Figure 8A and Figure 8B is a view of another alternative embodiment of a double-acting valve assembly shown in , wherein the valve stem between the first valve body and the second valve body is adjustable and the spacer between the first valve housing and the second valve housing is also adjustable.

[0046] Figure 13 is a cross-sectional view through the following mating parts, Figure 10A and Figure 10B The double-acting valve assembly shown in is installed in the fitting. The valve assembly is shown in a first operating mode.

[0047] Figure 14 is similar to Figure 13, showing a cross-sectional view of a double-acting valve assembly inserted into a main channel of a T-shaped fitting in opposite directions to provide different operating flows, wherein the double-acting valve assembly is shown in a first operating position.

[0048] Figure 15 is similar to Figure 14 A view showing Figure 10A and Figure 10B A double-acting valve assembly with the additional feature of a pipe fitting to hold the double-acting valve assembly in place, and an exemplary application as a backwash valve in a water heater heat exchanger circuit. DETAILED DESCRIPTION

[0049] Certain terms are used in the following description for convenience only and are not limiting. The words "right", "left", "upper" and "lower" indicate directions with reference to the accompanying drawings. The words "a" and "an" as used in the claims and corresponding parts of the specification are defined to include one or more of the items referred to, unless otherwise stated. The term includes the words specifically mentioned above, their derivatives and words of similar meaning. The phrase "at least one" followed by a list of two or more items (such as "A, B or C") refers to any single item of A, B or C and any combination thereof. The term "approximately" or "substantially" generally means within ±10% of the specified value, unless otherwise specified; and within ±25° of a specified angle or direction.

[0050] With respect to the valve being "closed," it should be noted that in certain embodiments, it may be desirable for some pressurized fluid or "main" flow (as described below) from the first region to enter and leak through the second valve body and / or valve seat to the third region, and still be considered the valve being "closed." However, the majority of the fluid cannot pass through a closed valve.

[0051] refer to Figure 1 and Figure 2 , a first embodiment of a double-acting valve assembly 10 is shown somewhat schematically. The valve assembly 10 is arranged between a first fluid region, a second fluid region and a third fluid region 21, 22, 23 (hereinafter also referred to as "ports"). The valve assembly 10 comprises a first valve 30, which preferably has a valve body 31 and a valve seat 32 (at Figure 3 5 ), as explained in further detail below, the first valve closes the first flow path 36 between the first fluid region 21 and the second fluid region 22 in the first operating mode (at Figure 1 and a second valve, which preferably includes a second valve seat 42 (in Figure 3 5 ), which, as explained in further detail below, is in an open position in a first operating mode, providing a second flow path 46 (at the bottom) between the second fluid region 22 and the third fluid region 23. Figure 1 In the second operating mode, when the pressure F1 of the fluid in the first fluid region 21 acting on the first valve body 31 overcomes the closing force of the first valve 30 (which may be the spring force F provided by the elastic element 34 as discussed below), the first valve 30 is closed. S ) and any pressure F2 of the fluid in the second fluid area 22 acts on the first valve body 31, the first valve 30 moves to the open position and simultaneously closes the second valve 40, so that the first flow path 36 between the first fluid area and the second fluid area is opened and the second flow path 46 is closed, isolating the third fluid area 23 from the first and second fluid areas 21, 22.

[0052] The double-acting valve assembly 10 operates simultaneously to open or close in response to operating conditions imposed on the valve assembly 10. The first valve 30 and the second valve 40 are configured so that the opening of one valve 30 or 40 results in the closing of the other valve 40 or 30, and vice versa. This is preferably achieved by a functional connection 50 between the valve bodies, as explained in more detail below. Typically, one of the valves (in these embodiments, the first valve 30) is in a closed position (i.e., a normally closed position, Figure 1 ) causes the second valve 40 to be in the open position (ie, the first operating mode 1, Figure 1 This condition causes the fluid in the first fluid region 21 to be isolated from the fluids in the second and third fluid regions 22, 23, while allowing the second and third fluid regions 22, 23 to interact with each other, for example, the fluid in the second fluid region 22 can flow into the third fluid region 23, or vice versa. When a sufficiently large pressure difference is applied to the first valve 30 acting on the first valve body 31 (see Figure 3 To Figure 5) (i.e. F1>F S +F2), the first valve is opened and the second valve 40 is closed, so that the valve assembly 10 is in the second operating mode, such as Figure 2 At this time, the fluid in the third fluid region 22 is isolated from the fluid in the second fluid region 22, while allowing the fluids in the first and second fluid regions 21, 22 to interact with each other, for example, the fluid in the first fluid region 21 can flow into the second fluid region 21. This results in a negative flow direction ( Figure 2 NF) flow.

[0053] When the pressure F1 acting on the first valve body 31 in the first fluid region decreases by an appropriate amount, or the pressure F2 acting on the opposite side of the first valve body 31 increases by an appropriate amount (which will be added to the spring force F S function), the first valve 30 returns to the "normally closed" position, and at the same time the second valve 40 returns to the normally open position, thereby returning to the first operating mode.

[0054] When the second valve 40 is closed, the main flow from the first fluid region 21 enters the second fluid region 22 and flows in the opposite direction NF through, for example, the heat exchanger 12 (described further below) or other flow components. There are situations that may occur during or after the backwash mode where the pressure in the second fluid region 22 may be greater than the pressure in the third fluid region 23, making it difficult for the second valve 40 to return to its open, non-backwash position. This can be overcome by providing a small, controlled leak through the second valve 40 between the second and third fluid regions 22, 23. This can be in the form of a small hole through the valve body and / or around the valve seat. The controlled leak ensures that the pressures can equalize after "pumping" occurs, reducing the additional pressure acting on the second valve 40, which may maintain the second valve to isolate the second and third fluid regions 22, 23.

[0055] like Figure 1 and Figure 2 As schematically shown in FIG, a first valve 30 is located in a first flow path 36, while a second valve 40 is located in a second flow path 46. The first valve 30 is normally closed, while the second valve 40 is normally open. In this configuration, there is typically occasional or continuous flow of a "primary" fluid through the second flow path 46, flowing from the second fluid region 22 to the third fluid region 23, or vice versa. For clarity, flow from the second fluid region 22 to the third fluid region 23 is designated in these figures as flow in a "positive" flow direction PF. Flow of the primary fluid through and from the second fluid region 22 to the third fluid region 23 can be initiated by a greater pressure in the second fluid region 22 relative to the third fluid region 23. This can occur due to depletion of the primary fluid, or due to an increase in pressure in the second fluid region 22 caused by an increase in the "primary fluid" supply pressure, which can itself be caused by a variety of means, such as the activation of a pump, a change in the primary fluid's elevation, a change in the fluid's volume or density caused by a temperature gradient, etc. Specifically, under steady flow conditions, the mass flow rate of fluid entering through port "B" in the second fluid region 22 will be equal to the mass flow rate exiting through the third fluid region 23. (In the case where the fluid is an incompressible liquid, the volumetric flow rate through the second fluid region 22 will also be equal to the volumetric flow rate through the third fluid region 23, except for small secondary effects that may occur, such as changes in the temperature of the liquid as it passes through the valve assembly.)

[0056] The first fluid region 21 is connected to a fluid source (e.g., mains water) such that it contacts the first valve 30, which can be in one of two positions (open or closed) depending on the operating conditions. Typically, the second valve 40 (located in the second flow path 46) is in the opposite position of the first valve 30 in the first flow path 36 (i.e., if the first valve 30 is in the closed position, the second valve 40 is in the open position; and if the first valve 30 is in the open position, the second valve 40 is in the closed position). As discussed below, the first and second valves 30, 40 are preferably located in a fitting 20 that is configured such that, in a first operating mode 1 (i.e., when the first valve 30 is closed and the second valve 40 is open), fluid can flow between the second and third fluid regions 22, 23, and fluid cannot flow from the first fluid region 21 to either or both of the second or third fluid regions 22, 23, or vice versa.

[0057] As discussed above, the first valve 30 is held in place by a "holding" force F S Held in the closed position. The "holding" force can be provided by a variety of mechanisms including, but not limited to: springs, magnets, gas pressure, bimetallic elements, or gravity.

[0058] In the first operating mode, the fluid flow through the first valve 30 is equal to or close to zero. In this mode, the fluid flow through the second fluid region 22 and the third fluid region 23 can be equal to or greater than zero, depending on the value of the pressures P2 and P3 in each of these regions. It is assumed that the assembly is not affected by other body forces (e.g., centrifugal forces, inertial forces, etc.), the magnitude of which significantly affects the normal operation of the valve assembly.

[0059] exist Figure 3 In the embodiment shown in FIG. 5 , valve bodies 31 , 41 in a first valve 30 and a second valve 40 are shown, and the valve bodies in the first and second valves are shown connected by a functional connection 50 (e.g., a rigid rod, shaft, or link 51 ) such that displacement of one results in a similar displacement of the other, as shown. Figure 3 Alternatively, the functional connection 50 may be any other suitable mechanical connection between the first valve 30 and the second valve 40 , a hydraulic or pneumatic interaction, a spring or a shape memory alloy or a magnetic force.

[0060] In this embodiment, when the pressure difference is insufficient, the force F applied by the elastic element 34 (eg, a spring) in the first valve 30 is S The valve body 31 is forced to press against the valve seat 32 to reach the normally closed position (and the second valve 40 remains in the normally open position), thereby maintaining or returning the first valve 30 to the first operating mode. S If necessary, it can be applied by other means (such as magnetic force, gas pressure, bimetallic elements, gravity, etc.). Figure 3and Figure 4 As shown in FIG, the distance between the first valve 30 and the second valve 40 is fixed for normal operation and is maintained at a distance that allows the valve assembly 10 to function properly. Proper placement of the valves 30, 40 can be achieved by adjusting Figure 3 The distance A shown in FIG or 5 may be achieved by setting the length of the connecting rod or link 51 to achieve proper operation of the valve assembly.

[0061] The magnitude of the "holding force" will be selected to ensure proper operation of the valve assembly 10 for a particular application, ensuring it switches between operating modes under desired operating conditions. In most cases, it is desirable to configure the valve assembly 10 such that, in the second operating mode, the hydrostatic pressure and drag force associated with fluid flow through the first valve 30 are sufficient to maintain the second operating mode until a return to the first operating mode is achieved. The transition to the first operating mode can be initiated by cessation of fluid flow through the first valve 30 and / or a reduction in the pressure gradient across the first valve 30, such that the valve holding force closes the first valve 30. In some cases, if a pressure differential (from the second fluid region 22 to the third fluid region 23) occurs during the second operating mode, it may be desirable to configure the second valve 40 to mitigate these effects or adjust for a particular application. This can be achieved by adjusting the "frontal area" of the valve body 41 of the second valve 40 exposed to pressure or by configuring the second valve 40 such that a controlled leakage through the second valve 40 balances the pressure differential between the second fluid region 22 and the third fluid region 23 within a specified time period.

[0062] The fluid here can be liquid, steam or gas.

[0063] refer to Figure 3 、 Figure 4 、 Figure 5A and Figure 5B , the first valve 30 is arranged in a first valve housing 38, which includes a first valve seat 32 and a resilient element 34 in the form of a spring. The resilient element is held between the first valve body 31 and a resilient element support 28 formed as part of the first valve housing 38. The resilient element support 28 may include two legs 53 extending from the area of the first valve seat 31 to a rod or shaft support 54. The first valve body 31 is connected to the second valve body 41 by a connecting rod or connecting rod 51, although a magnetic coupling or a hydraulic or pneumatic connection may also be used. In this case, the second valve seat 42 is integrally formed in a part of the fitting 20, as Figure 5A and 5B The specific operation is as described above to provide a first operating mode and a second operating mode caused by the pressure difference acting on the first valve body 31, which is greater than or less than F S The pressure F1 in combination with the pressure F2 acting on the first valve body 31 , as described above, causes the valve assembly to switch between the first and second operating modes.

[0064] Now refer to Figure 6 and Figure 7 , Figure 3 The double-acting valve assembly 10 is shown installed in a T-shaped fitting 20. The first valve seat 32 and the second valve seat 42 are located along the same axis in the main passage 20a that passes through the T-shaped piece, and the transverse passage 20b of the T-shaped piece intersects the main passage 20a at a position between the first valve seat 32 and the second valve seat 42.

[0065] The first valve housing 38 preferably includes a shoulder 39 that abuts against a corresponding shoulder 29 in the wall 26 of the main passage 20a. The second valve seat 42 is a fixed distance A from the shoulder to control the distance between the first valve 30 and the second valve 40 to ensure proper operation.

[0066] Here, the first valve seat 32 and the second valve seat 42 are located in the fitting body 20 and may be integrally formed or inserted therein. The first fluid region 21 is located on a first side of the first valve seat 32, the second fluid region 22 is located on a second side of the first valve seat 32 opposite the first fluid region 21 and on a first side of the second valve seat 42, and the third fluid region 23 is located on a second side of the second valve seat 42 opposite the second fluid region 22.

[0067] Now refer to Figure 8A 、 Figure 8B 、 Figure 9A 、 Figure 9B 、 Figure 10A 、 Figure 10B and Figures 11 to 15 , shows a second embodiment of a double-acting valve assembly 10 '. The second embodiment of the double-acting valve assembly 10 ' is similar to the first embodiment, except that it is designed to provide a fitting, device or assembly that can be inserted into an existing fitting 20 ' (see Figures 13 to 15 ) with little or no modification. The first valve 30' and the second valve 40' are each provided with a respective first valve housing 38' and a second valve housing 48'. The first valve seat 32' is formed in the first valve housing 38', while the second valve seat 42' is formed in the second valve housing 48'. The first valve body 31' is located within the first valve housing 38', while the second valve body 41' is located within the second valve housing 48', and the first and second valve housings 38', 48' are insertable into a fitting 20', which may be in the form of a standard T-piece. The first and second flow paths 36', 46' are also shown passing through the first and second valves 30', 40'.

[0068] The functional connection 50' between the first valve body 31' and the second valve body 41' is preferably in the form of a rod, shaft or connecting rod 51'. Preferably, an elastic element 34' in the form of a spring is located in the first valve housing 38'. In order to allow a sealing interface between the first, second and third fluid areas 21, 22, 23 (see in particular Figures 13 to 15 ), the first seal 37 'and the second seal 47 'are preferably located on the respective first valve housing 38 'and the second valve housing 48 'and are configured to seal against the channel wall 26 'of the main channel 20a 'of the fitting 20 ', as shown Figures 13 to 15 . To this end, the first housing 38' and the second housing 48' preferably have cylindrical outer walls, and the seals 37', 47' are located in circumferential grooves in the respective cylindrical outer walls and are sized to provide sealing contact with the cylindrical channel wall 26' of the fitting 20'. It is contemplated that the first valve housing 38' and the second valve housing 48' can be produced with different diameters to match the existing inner diameter of the channel of an existing fitting, device or assembly.

[0069] like Figure 9A and Figure 9B As shown in FIG, a separate spacer 60' (two shown) may be provided between the first valve housing 38' and the second valve housing 48' to set the appropriate distance A between the first valve 30' and the second valve 40' as described above. Figure 10A and Figure 10B As shown in FIG, the spacer 62' may be in the form of a tube surrounding the stem 51' and secured to the first valve housing 38' and the second valve housing 48'.

[0070] Now refer to Figure 11 The rod 51' can have an adjustable length, for example, formed from two parts 51a', 51b', wherein the first part 51a' includes a male thread and the second part 51b' includes a female thread. This allows the rod length to be adjusted based on the specific application and the distance A dictated by the variable conditions. This arrangement also accommodates the insertion and subsequent connection of the first and second valve housings 38', 48' from opposite ends of a particular mating body 20'.

[0071] In addition, if Figure 12As shown in FIG, an adjustable rod 51' can be combined with an adjustable spacer 64', which is also formed in two parts 64a', 64b', wherein the first part 64a' includes a male thread and the second part 64b' includes a female thread. This arrangement not only allows the length of the rod 51' to be adjusted, but also allows the distance A to be set to suit the existing conditions in a given existing fitting, device, or assembly forming the fitting 20'. This arrangement also accommodates the insertion and subsequent connection of the first valve housing 38' and the second valve housing 48' from opposite ends of a particular fitting 20'. Other arrangements will also be able to achieve this adjustability.

[0072] Figures 13 to 15 Insertion of valve assembly 10' into a "T" shaped pipe fitting or tube (with an outlet in the sidewall) or other fluid device is shown as fitting 20'. Double acting valve assembly 10' can be inserted into the fitting in either direction to suit the end use. Figure 13 and 14 The dashed lines in FIG. 1 represent fluid flow in a "positive" flow direction. Preferably, the first valve housing 38' and the second valve housing 48' are received within the inner wall 26' of the mating body 20' with a friction fit. Alternatively, other mechanical attachments or arrangements may be used to hold the first valve housing 38' and the second valve housing 48' in place. For example, a shoulder and / or a split ring and groove arrangement in the mating parts may be used.

[0073] Figure 15 Typical port fitting options (i.e., "female" internal threads, "male" external threads, or glued or welded pipe "inserts," etc.) that may be present on pre-existing piping components are shown, which may form the fitting 20' and may be used in any combination to facilitate connection to a piping component equipped with the valve assembly 10'. An optional flange 68' is shown on the first valve housing 38' to limit the insertion depth.

[0074] Additionally, Figure 15An exemplary application of a double-acting valve assembly 10' as a backwash valve is shown. Here, the thermal energy system according to the present invention is a water heating system, such as one used to supply domestic drinking water. The primary circuit is a closed-loop circuit comprising a heat source 13 and suitable pipes or tubing for circulating a heat transfer fluid between the heat source 13 and the primary side of a heat exchanger 12. Optionally, a pump may be inserted into the primary circuit to facilitate circulation of the heat transfer fluid. In some embodiments, such as those employing a water-based heat transfer fluid (e.g., a water-propylene glycol solution), the primary circuit additionally includes an expansion tank (not shown) to compensate for expansion / contraction of the heat transfer fluid as its temperature changes. The system's secondary circuit comprises the secondary side of the heat exchanger 13, a water storage tank 14, and the double-acting valve assembly 10', which functions as a backwash control valve. Hot water is drawn from the top of the water storage tank 14 via a pipe or tube 15. Due to the pressure imbalance caused by the hot water exiting through the pipe or tube, primary water 11 enters the double-acting valve assembly 10' through a first fluid region or port 21.

[0075] As used herein, the term "primary water" refers to water that enters the system from a water source (eg, a city water distribution network or a well). Primary water enters the secondary circuit of the system to be heated or cooled.

[0076] Figure 15 The valve assembly 10' is shown in a first operating mode, wherein the valve assembly 10' allows hot water to circulate through the second flow path 46', and water is not drawn from the system through the pipe 15, and water is not entering the valve assembly 10' through the first flow path 36. In this first operating mode, the flow direction of the fluid (water in this example) is through Figure 15 This embodiment operates as follows: when water is not being drawn from the storage tank 14, water circulates through the secondary side of the heat exchanger 12 and the storage tank 14, causing heated water to flow upward (in the figure) through the heat exchanger 12 and the second flow path 46' of the valve assembly 10' into the top of the tank 14 and out of the bottom of the tank into the heat exchanger 12. This flow can be established by a pump, or by convection; if a pump is used, the pump needs to allow reverse flow to occur, for example by using a known centrifugal pump, or a bypass valve assembly can be provided.

[0077] When water is drawn from the storage tank 14, the double-acting valve assembly is passively switched to the second operating mode, opening the first flow path 36' and closing the second flow path 46' due to the pressure imbalance caused by drawing water from the hot water tank 14. The pressure of the fluid from the main water supply in the first fluid area 21 overcomes the closing force F of the elastic element 34'. SThe first valve body 31' is moved to the open position by the first and second valve bodies 41', and any pressure F2 of the fluid in the second fluid region 22, while simultaneously moving the second valve body 41' to the closed position against the second valve seat 42', thereby opening the first flow path 36' and closing the second flow path 46' between the first and second fluid regions 21, 22. The primary water is then directed through the secondary side of the heat exchanger 12 and enters the storage tank 14 at the bottom. Furthermore, the flow of the primary water through the secondary side of the heat exchanger 12 is in the opposite direction to the flow of water during heating (when no primary water is introduced into the system). This opposite flow direction provides for passive backwashing of the secondary side of the heat exchanger 12. Thus, each time water is drawn from the storage tank 14, the secondary side of the heat exchanger 12 is passively backwashed.

[0078] This backflushing can also be accomplished using the double-acting valve assembly 10 in the same manner.

[0079] In another aspect, a method for passively backwashing a flow component (e.g., a heat exchanger 12 of a thermal energy system) is provided. The method comprises:

[0080] A. A valve assembly 10, 10' for communicating with first, second, and third fluid regions 21, 22, 23 is provided, the valve assembly being configured to passively switch between a first operating mode and a second operating mode, wherein the valve assembly 10, 10' comprises: a first valve 30, 30', preferably comprising a first valve body 31, 31' biased by a resilient element 34 to a closed position against a first valve seat 32, 32' to close a first flow path between the first fluid region 21 and the second fluid region 22 in the first operating mode; and a second valve 40, 40', preferably comprising a second valve body 41, 41' acting against a second valve seat 42, 42'. In the first operating mode, the second valve 40, 40' is in an open position, preferably with the second valve body 41, 41' spaced apart from the second valve seat 42, 42', providing a second flow path 46 between the second fluid region 22 and the third fluid region 23. providing a functional connection 50, 50' between the first valve 30, 30' and the second valve 40, 40', and more preferably providing a functional connection between the second valve body 41, 41' and the first valve body 31, 31', such that movement of the first valve body 31, 31' to the closed position moves the second valve body 41, 41' to the open position, and movement of the first valve body 31, 31' to the open position moves the second valve body 41, 41' to the closed position;

[0081] B. Connecting the first fluid zone 21 to the main water supply or pressurized fluid source;

[0082] C. Connecting the second fluid region 22 to the inlet side of the flow component, which in one embodiment is the cooler side of the heat exchanger 12 of the thermal energy system;

[0083] D. Connecting the third fluid region 23 to the outlet side of the flow component, which in one embodiment is the hotter side of the heat exchanger 12 of the thermal energy system;

[0084] E. In a first operating mode, maintaining the second valve bodies 41, 41' in an open position spaced apart from the second valve seats 42, 42' provides a second flow path 46 between the second fluid region 22 and the third fluid region 23, allowing fluid to flow in a first direction from the cooler side or inlet side to the hotter side or outlet side by convection or other means (e.g., when the fluid on the cooler side is heated or otherwise induced to flow in that direction); and

[0085] F. In the second operating mode, when the pressure of the fluid from the main water supply or other pressurized fluid source in the first fluid region 21 overcomes the closing force F of the elastic element 34 S and any pressure F2 of the fluid in the second fluid region 22, the first valve bodies 31, 31' are moved to the open position, and at the same time the second valve bodies 41, 41' are moved to the closed position against the second valve seats 42, 42', so that the first flow path 36 is opened and the second flow path 46 is closed between the first fluid region 21 and the second fluid region 22, isolating the third fluid region 23 from the first and second fluid regions 21, 22, and allowing the fluid from the main water supply or other pressurized fluid source to flow into the second fluid region 22 in a second direction opposite to the first direction.

[0086] The method may further include inserting the valve assembly into the fitting 20 , 20 ′ defining the first, second and third regions 21 , 22 , 23 .

[0087] In a preferred embodiment, the method further includes integrally forming at least one of the first valve seat and the second valve seat 32 , 42 into a fitting body.

[0088] In a preferred arrangement, the method further comprises providing the functional connection 50 as a mechanical linkage 51 , a magnetic coupling or a hydraulic or pneumatic connection.

[0089] In association with the second embodiment of the mating assembly 10 ′, the method may further include inserting the first and second valve housings 38 , 38 ′ into the passageway of the mating body 20 ′.

[0090] It should be understood that the foregoing is presented in an exemplary and non-limiting manner only. It is contemplated that various substitutions and modifications may be made to the embodiments without departing from the spirit and scope of the present invention. Therefore, after describing the present invention in detail, it will be understood by those skilled in the art and it will be apparent to those skilled in the art that many physical changes (only some of these physical changes are exemplified in the detailed description of the present invention) may be made without changing the innovative concepts and principles of the present invention. It will also be understood that numerous embodiments comprising only a portion of the preferred embodiment may be implemented without changing the innovative concepts and principles contained therein with respect to these portions. Therefore, the present embodiment and optional configurations are to be considered exemplary and / or illustrative in all respects and not restrictive, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and all alternative embodiments and modifications to the present embodiment falling within the meaning and equivalent scope of the claims should be included therein.

Claims

1. A valve assembly for communicating with a first fluid region, a second fluid region, and a third fluid region, the valve assembly being configured to passively switch between a first operating mode and a second operating mode, the valve assembly comprising: a first valve body biased by a resilient element to a closed position against a first valve seat to close a first flow path between the first fluid region and the second fluid region in a first operating mode; a second valve body, the second valve body acting on a second valve seat, wherein in the first operating mode, the second valve body is in an open position spaced apart from the second valve seat, providing a second flow path between the second fluid region and the third fluid region; a functional connection between the second valve body and the first valve body such that movement of the first valve body toward the closed position causes the second valve body to move toward the open position, and movement of the first valve body toward the open position causes the second valve body to move toward the closed position; wherein, in the first operating mode, the second valve body is in an open position spaced apart from the second valve seat, opening a second flow path between the second fluid region and the third fluid region; and In the second operating mode, when the fluid pressure in the first fluid area overcomes the closing force of the elastic element and any pressure of the fluid in the second fluid area, the first valve body can be moved to the open position, while simultaneously moving the second valve body to the closed position against the second valve seat, so that the first flow path is opened between the first fluid area and the second fluid area, and the second flow path is closed, isolating the third fluid area from the first fluid area and the second fluid area.

2. The valve assembly according to claim 1, wherein The valve assembly is configured to return to the first operating mode when the spring force and any pressure in the second fluid region overcomes the fluid pressure in the first fluid region.

3. The valve assembly according to claim 1, wherein The elastic element is a spring.

4. The valve assembly according to claim 1, wherein The functional connection is a mechanical linkage, a magnetic coupling or a hydraulic or pneumatic connection.

5. The valve assembly according to claim 1 further comprises a fitting body, wherein the first valve seat and the second valve seat are located within the fitting body, and the first fluid region is located on a first side of the first valve seat, the second fluid region is located on a second side of the first valve seat opposite to the first fluid region and on the first side of the second valve seat, and the third fluid region is located on a second side of the second valve seat opposite to the second fluid region.

6. The valve assembly according to claim 5, wherein At least one of the first valve seat and the second valve seat is integrally formed in the fitting body.

7. The valve assembly according to claim 5, wherein: The first valve seat is arranged in a first valve housing which can be inserted into the fitting body, and the second valve seat is integrally formed in the fitting body.

8. The valve assembly according to claim 5, wherein The first valve seat and the second valve seat are inserted into the fitting body.

9. The valve assembly according to claim 8, further comprising: a first valve housing in which the first valve seat is formed; and a second valve housing in which the second valve seat is formed, the first valve body being located in the first valve housing, the second valve body being located in the second valve housing, and the first valve housing and the second valve housing being insertable into the fitting body.

10. The valve assembly according to claim 9, wherein The functional connection includes a rigid member extending between the first valve body and the second valve body.

11. The valve assembly according to claim 10, wherein: The length of the rod is adjustable.

12. The valve assembly according to claim 9, wherein The elastic element is located in the first valve housing.

13. The assembly of claim 9, further comprising: A first seal is provided between the first valve housing and the channel wall of the fitting body, and a second seal is provided between the second valve housing and the channel wall of the fitting body.

14. The valve assembly according to claim 5, wherein The functional connection is a rod or connecting rod extending between the first valve body and the second valve body. 15 . The valve assembly according to claim 14 , further comprising an elastic element support member located in the fitting body, wherein the elastic element is disposed between the elastic element support member and the first valve body.

16. The valve assembly according to claim 5, wherein The fitting is T-shaped, and the first valve seat and the second valve seat are located along the same axis in a main channel passing through the T-shaped piece, and a transverse channel of the T-shaped piece intersects with the main channel at a position between the first valve seat and the second valve seat.

17. A method for passively backwashing a flow component or a heat exchanger of a thermal energy system, the method comprising: A valve assembly for communicating with a first fluid region, a second fluid region, and a third fluid region is provided, the valve assembly being configured to passively switch between a first operating mode and a second operating mode, the valve assembly comprising: a first valve body biased by a resilient element to a closed position against a first valve seat to close a first flow path between the first fluid region and the second fluid region in the first operating mode; a second valve body acting on a second valve seat, the second valve body being in an open position spaced from the second valve seat in the first operating mode to provide a second flow path between the second fluid region and the third fluid region; and a functional connection between the second valve body and the first valve body such that movement of the first valve body to the closed position causes the second valve body to move to the open position, and movement of the first valve body to the open position causes the second valve body to move to the closed position; connecting the first fluid zone to a main water supply or a source of pressurized fluid; connecting the second fluid region to an inlet of the flow component or an inlet or cooler side of a heat exchanger of the thermal energy system; connecting the third fluid region to an outlet of the flow component or an outlet or warmer side of a heat exchanger of the thermal energy system; In the first operating mode, maintaining the second valve body in an open position spaced apart from the second valve seat provides a second flow path between the second fluid region and the third fluid region, such that fluid flows from the inlet or cooler side to the outlet or warmer side through the second flow path in a first direction by convection or other means; and In the second operating mode, when the pressure of the fluid from the main water supply or other pressurized fluid source in the first fluid area overcomes the closing force of the elastic element and any pressure of the fluid in the second fluid area, the first valve body is moved to the open position, and the second valve body is simultaneously moved to the closed position against the second valve seat, so that the first flow path is opened and the second flow path is closed between the first fluid area and the second fluid area, isolating the third fluid area from the first and second fluid areas, and providing a flow of fluid from the main water supply or other pressurized fluid source in the second fluid area along a second direction opposite to the first direction.

18. The method according to claim 17, further comprising: The valve assembly is inserted into a fitting defining the first, second, and third regions.

19. The method according to claim 18, further comprising: The first valve seat and the second valve seat are integrally formed in the fitting body.

20. The method according to claim 17, wherein The functional connection is a mechanical linkage, a magnetic coupling or a hydraulic or pneumatic connection.

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