GB2579890A

GB2579890A - Proportional valve and also a heating and/or cooling system with a proportional valve

Info

Publication number: GB2579890A
Application number: GB1914660.4A
Authority: GB
Inventors: Blok Jan; Prestle Thomas
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2018-10-18
Filing date: 2019-10-10
Publication date: 2020-07-08
Anticipated expiration: 2039-10-10
Also published as: GB201914660D0; GB2579890B; DE102018217832A1

Abstract

The proportional valve comprises at least one heating water passage 16 controlled by a valve, and at least one potable water passage 18 controlled by a further valve, wherein the valves have valve members 22,28 coupled together, ideally by a rod 32 or springs. A first 22 of the valve members is connected to a diaphragm 34 that divides a valve chamber 36 into first 28 and second 40 sub-chamber. The first sub-chamber has a first opening 42 controlled by the first valve member 22 and a second opening 44 narrowed by a venturi assembly 46. A channel 50 is provided from the venturi assembly to the second sub-chamber. A heating and/or cooling system including the proportional valve is also claimed. Ideally the valve has a first passageway 66 controlled by the first valve member and a further passageway 70 controlled by a spring-loaded third valve member 68. The valve ideally has a bypass path 62 having a cross-section adjustable by a screw 64 or slider and which circumvents the venturi assembly.

Description

Proportional valve and also a heating and/or cooling system with a proportional valve

Prior art

With DE 102010050953 Al a flow rate regulator for heating and/or cooling systems was disclosed which has two flow paths separated from each other, wherein a pressure-controlled actuator is disposed in one flow path.

Disclosure of the invention

Advantages The proportional valve according to the invention with the features of the main claim, which is characterised in that a diaphragm divides a valve chamber into at least a first and a second sub-chamber, that the first sub-chamber has a first opening controlled by the first valve member and a second opening narrowed by a venturi assembly and that a channel is provided from the venturi assembly to the second sub-chamber, has the advantage that from the flow of the fluid through the venturi assembly a difference in pressure acting on a diaphragm can be adjusted.

A venturi assembly is understood to mean a flow path that narrows in the direction of flow and widens again. Due to the increase in the speed of the fluid at the narrow point, there the pressure falls perpendicularly to the flow direction. This reduction in pressure can be used to advantage via an opening branching off at the narrow point.

With the features listed in the dependent claims, advantageous further embodiments of the proportional valve are possible. For example, the first sub-chamber may preferably be connected to a potable water pipe so that potable water can flow through the first sub-chamber.

Advantageously, a flow of fluid through the venturi assembly produces a negative pressure in the second sub-chamber so that the diaphragm experiences a deflection a dependent on the value of the negative pressure, which preferably transfers itself to the position of the valve members.

Advantageously, a deflection a of the diaphragm causes the first valve member to move to the valve seat assigned to it.

it is also of advantage when the deflection a of the diaphragm moves the second valve member from the valve scat assigned to it.

The proportional valve can be used variably if the heating water passage has a first passageway controlled by the second valve member and a further passageway controlled by a third valve member.

If a further passageway branches off from the first passageway, this can create a further circuit through which the sane fluid flows.

Easy adjustability is produced if the third valve member is spring-loaded.

The variability of the adjustability is increased if the third valve member is loaded by a first spring, which is supported on a housing part and is loaded by a second spring which is supported on the second valve member. The first spring can here preferably be made such that it is adjustable 15 mechanically.

In a heating system according to the invention with a proportional valve according to the invention, preferably the flow rates of potable water and heating water depend on each other at least in some areas. They are proportional to each other in particular in some areas.

Drawing The figure shows schematically a proportional valve according to the invention. A heating system according to the invention and/or their flow paths is/are also drawn in.

Description

The figure shows a proportional valve 10 for a heating system 12. Of the heating system 12, only the paths to be connected to the proportional valve 10 are shown dot-dashed and also a heat exchanger 14.

The proportional valve 10 controls or regulates two separate fluid circuits in such a way that the flow rate in one fluid path influences the flow rate in the other fluid path. For this, heating water flows through a heating water passage 16 and potable water flows through a potable water passage 18 of the proportional valve 10 according to the invention.

The potable water passage 18 is controlled by a first valve 20 with a first valve member 22, which cooperates with a first valve scat 24. The heating water passage 16 is controlled by a second valve 26 with a second valve member 28, which cooperates with a second valve scat 30.

The first valve member 22 is coupled to the second valve member 28. For this, the proportional valve has a rod 32, to which the valve members 22, 26 are attached. A movement of one valve member therefore also causes a movement of the other valve member.

in the embodiment, in the area of the first valve member 22 a diaphragm 34 is disposed, which is connected to the first valve member 22. The connection is brought about by the rod 32.

A valve chamber 36 is formed behind the first valve seat 24. This valve chamber 36 is divided by the diaphragm 34 into a first sub-chamber 38 and a second sub-chamber 40.

The first sub-chamber 38 has a first opening 42 controlled by the first valve member 22. Also, the first sub-chamber 38 has a second opening 44, which is narrowed by a venturi assembly 46. From the narrow point 48 of the venturi assembly 46 a channel 50 branches off which leads to the second sub-chamber 40.

Potable water, illustrated by a dot-dashed line 52, that flows through the potable water passage 18, enters the proportional valve 10 via a potable water inlet 54, strikes the first valve member 22, flows through the first opening 42 into the first sub-chamber 38, from there through the second opening 44, then through the venturi assembly 46 and leaves the proportional valve 10 through a potable water outlet 56.

The assembly is made such that a flow of fluid through the venturi assembly 46 produces a negative pressure via the channel 50 in the second sub-chamber 40. Because of the difference in pressure caused as a result between the first sub-chamber 38 and the second sub-chamber 40, a force acts on the diaphragm 34 which causes it to make a deflection a. This deflection a is dependent on the negative pressure produced and therefore directly on the flow of fluid through the venturi assembly 46. The size of the deflection a shown in the embodiment therefore visualises one of many different positions.

To absorb the force produced by the difference in pressure, the diaphragm 34, which is elastic, is connected to a stable disc 58. The disc 58 consists preferably of a harder plastic or even of a metal.

The diaphragm 34 consists of an elastomer.

The diaphragm 34 or the disc 58 is connected to the rod 32. With this, the deflection a of the diaphragm 34 is transferred to the first valve member 22 and also to the second valve member 28. With this, the positions of the valve members 24, 28 also change by the distance a.

In a variant not shown it is possible that the coupling between the diaphragm 34 and the individual valve members 24, 28 is not made directly, so that the stroke of the diaphragm 34 is not transferred identically to the first valve member 24 and/or the second valve member 28. Such a coupling could for example be made by means of spring elements.

The connection between the first valve member 22 and the diaphragm 34 is made such that by the deflection a the first valve member 22 is moved in the direction of the first valve seat 24 assigned to it. With this, the first valve 20 restricts the flow of the potable water through the potable water passage 18.

The connection between the second valve member 28 and the diaphragm 34 is made such that by the deflection a the second valve member 28 is moved away from the second valve seat 30 assigned to it.

With this, the second valve 26 increases its opening and the flow of heating water, shown by the dashed lines 59, through the heating water passage 16.

The first valve seat 24 points away from the second valve seat 30.

When the proportional valve 10 is in the neutral position, so when no potable water flows through the potable water passage 18, the second valve member 28 bears on its valve seat 30, while the first valve member 22 is lifted from its valve seat 24. To select this position, a spring 60 is provided which exerts such a force on the second valve member 28 that a bearing of the second valve member 28 on the second valve seat 30 is ensured.

If potable water now flows through the potable water passage 18, this produces a negative pressure which leads to a deflection a and with this both reduces the potable water flow and also increases the heating water flow. With this a balance is established regularly between the amount of potable water and the amount of heating water, which can be used to produce a certain potable water temperature. Over an area the flow rate of heating water is proportional to the flow rate of potable water.

Parallel to the venturi assembly 46 the proportional valve 10 has a bypass path 62, the cross-section of which is changeable. For this, a screw 64 or a slider, not shown, can be introduced into the bypass path 62. Via this bypass path 62 changeable in cross-section the balance becoming established between the amount of potable water and the amount of heating water can be shifted.

In the area of the heating water passage 16, next to the passageway 66 controlled by the second valve member 26 there is a further passageway 70 controlled by a third valve member 68 of a third valve 69. inside the proportional valve 10 this further passageway 70 branches off from the first passageway 66. With this, the flow of heating water divides into at least two part-flows.

The third valve member 68 is spring-loaded and controls a third valve seat 72. The part-flows of the healing water are determined by the respective degrees to which the second valve 26 and the third valve 69 are open.

in the embodiment the third valve member 68 is loaded by a first spring 74 which is supported on a housing part 76 of the proportional valve 10. This first spring 74 is disposed such that the third valve member 68 experiences a force which enables it to lift from the third valve scat 72.

The third valve member 68 is also loaded by a second spring 78 which is supported on the second valve member 22. In the embodiment the second spring 78 is realised by the spring 60. With this, via the spring 60 respectively 78 the deflection a of the second valve member 28 brought about by the diaphragm acts on the third valve member 68. The position of the third valve member therefore results due to a balance of forces of the springs 60 respectively 78 and 74. In the embodiment the first spring 74 acts against the spring 60.

In a variation, not shown, the springs 78 and 60 can also be present as separate components. It is also possible that the first spring 74 and the second spring 78 act in a same direction. It is also possible that the second valve member 22 and the third valve member 68 are rigidly connected to each other. in the embodiment the second valve scat 30 and the third valve scat 72 point to each other. It is also possible however that the two valve scats 30 and 72 point in the same direction. The valve members 22, 26 and 68 are called disc valves. But here also for individual or all valve members, conical, spherical or flap-like valve members may be provided.

As well as the proportional valve 10 and the heat exchanger 14, the heating system 12 usually has further components such as pumps, valves, at least one heat generator, a control device etc., which are not shown here. Also the pipes carrying the fluids are only shown here dot-dashed.

In the embodiment the cold potable water flows along the line 52 through the proportional valve 10, then through the heat exchanger 14, where it is heated. Then it passes to one or more removal points, not shown.

The heating water, which is heated by a heat generator, not shown, flows through the heat exchanger 14, there gives off heat to the potable water and from there passes into the proportional valve 10. In the embodiment, in the proportional valve 10, depending on the position of the valve, it is distributed into the part flows of the passageway 66 and the further passageway 70. From there, via various heat release points it returns back to the heat generator.

The representation of the heating system 12 is shown here only by way of example. Its actual design may be different, adapted Lo the conditions in situ.