GB2620595A

GB2620595A - A valve arrangement

Info

Publication number: GB2620595A
Application number: GB2210241.2A
Authority: GB
Inventors: Jarvis Michael
Original assignee: HORNE ENGINEERING Ltd
Current assignee: HORNE ENGINEERING Ltd
Priority date: 2022-07-12
Filing date: 2022-07-12
Publication date: 2024-01-17
Also published as: GB202210241D0

Abstract

A valve arrangement 10 is provided which comprises a first thermostatic mixing valve (FTMV) 12 and a second thermostatic mixing valve (STMV) 14. The FTMV has first and second FTMV inlets 16,18, and a FTMV outlet 20. The STMV 14 has first and second STMV inlets 26,28, and a STMV outlet 3. The FTMV outlet 20 is fluidly connected with the first STMV inlet 26. The FTMV outlet may be fluidly connected to a shower 39 or a tap 38. The arrangement may comprise a first fluid source 22 connected to the FTMV inlet, and a second fluid source 24 having a greater temperature than the first fluid wherein the second fluid source is connected to the second FMV inlet and the second STMV. The arrangement may comprise a heat pump 24 and a heat exchanger 24 arranged to receive heat from the heat pump. A plumbing system 100 comprising the valve arrangement, and a method of providing fluid to a discharge outlet utilising the valve arrangement, are also provided.

Description

A VALVE ARRANGEMENT

Field of Invention

This invention relates to thermostatic mixing valves, and specifically to a valve arrangement incorporating such valves. The invention also relates to a plumbing system incorporating the valve arrangement and a method of operating the valve arrangement.

Background

Thermostatic mixing valves are valves that mix hot and cold water to a certain temperature. They are configured to minimise the risk of the mixed water exceeding the certain temperature and scalding a user downstream. These valves are well known and employed in domestic and commercial plumbing systems.

Figure 1 shows a thermostatic mixing valve (TMV) 1. Cold water enters the TMV via a cold water inlet 2 and hot water enters the TMV via a hot water inlet 3. The TMV includes a slide-valve 4, which is connected to an expandable element 5. The expandable element 5 expands/contracts in response to changes in temperature of fluid entering the TMV to move the valve element 4 axially within the TMV to ensure the mixed water leaving the TMV 1 via mixed flow outlet 6 is of a certain temperature. The slide-valve 4 moves from its position during normal operating conditions towards an internal surface 7 of a valve body 8 of the TMV, which limits axial movement of the slide-valve 4, when there is a surge in hot water temperature. This internal surface 7 is called the hot seat. As shown, there is a gap 9 between the slide-valve 4 and the hot seat. This is called the hot gap and hot water enters the mixed flow via the hot gap. When the hot gap is closed or reduced in size by the slide-valve 4 the temperature of the mixed water leaving the TMV is reduced.

The difference between the hot inlet temperature and the mixed outlet temperature can be defined as Delta-Hot. Similarly, the difference between the cold inlet temperature and the mixed outlet temperature can be defined as Delta-Cold. If Delta-Cold is significantly larger than Delta-Hot (as is often the case with TMVs connected to low temperature heat networks), then the position of the slide-valve in normal operating conditions is a relatively large distance away from the hot seat. The hot gap is therefore large, meaning that in the case of a sudden surge in hot water temperature, hot water can pass by the slide-valve before the expanding element can react to reduce the temperature of the mixed flow, leading to potential scalding downstream.

It is an object of the present invention to overcome one or more problems with existing valve arrangements.

Summary of Invention

According to a first aspect of the present invention, there is provided a valve arrangement comprising: a first thermostatic mixing valve (FTMV) having: first and second FTMV inlets, and a FTMV outlet; and a second thermostatic mixing valve (STMV) having: first and second STMV inlets, and a STMV outlet; wherein the FTMV outlet is fluidly connected with the first STMV inlet.

The FTMV outlet may be fluidly connectable to a first fluid dispensing device.

The FTMV may comprise a FTMV valve body and the STMV may comprise a STMV valve body, wherein the FTMV valve body and the STMV valve body may be formed as one piece.

The valve arrangement may comprise at least one duct and the FTMV outlet may be fluidly connected with the first STMV inlet by way of the at least one duct. The at least one duct may be arranged to convey mixed fluid from the FTMV outlet to the first STMV inlet.

According to a second aspect of the present invention, there is provided a plumbing system comprising: the valve arrangement of the first aspect; a first source of a first fluid, the first source being fluidly connected with the first FTMV inlet; a second source of a second fluid with a greater temperature than the first fluid, the second source being fluidly connected with the second FTMV inlet and the second STMV inlet; and a first closable discharge outlet fluidly connected to the STMV outlet.

The FTMV outlet may be fluidly connected to a second closable discharge outlet.

Each of the first closable discharge outlet and second closable discharge outlet may form part of a shower or tap device.

The plumbing system may further comprise a heat pump and a heat exchanger arranged to receive heat from the heat pump, wherein the second fluid of the second source may comprise the first fluid from the first source passed through the heat exchanger.

Each of the first and second fluids may be water.

The temperature of the first fluid may be 25 °C or less, wherein the temperature of the second fluid may be 35 °C or greater.

According to a third aspect of the present invention, there is provided a method of providing fluid to a discharge outlet, comprising: providing the valve arrangement of the first aspect; connecting the first FTMV inlet to a first source of a first fluid and connecting the second FTMV inlet and second STMV inlet to a second source of a second fluid with a greater temperature than the first fluid; mixing, in the FTMV, the first fluid and the second fluid to produce a first thermally mixed fluid; conveying the first thermally mixed fluid to the STMV; mixing, in the STMV, the first thermally mixed fluid with the second fluid to produce a second thermally mixed fluid; and conveying the second thermally mixed fluid via the STMV outlet to the discharge outlet.

The fluid may be water.

The temperature of the first thermally mixed fluid may be 25°C or greater, wherein the temperature of the second thermally mixed fluid may be 35°C or greater.

Brief Description of the Drawings

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a thermostatic mixing valve; and Figure 2 shows a plumbing system incorporating a valve arrangement of the present invention.

Detailed Description of the Drawings

With reference to Figure 2, there is shown a plumbing system 100 incorporating a valve arrangement 10 according to the present invention. The valve arrangement 10 includes a first thermostatic mixing valve (FTMV) 12 and a second thermostatic mixing valve (STMV) 14. The FTMV 12 has a first FTMV inlet 16 and a second FTMV inlet 18 as well as a FMTV outlet 20. The first FTMV inlet 16 is fluidly connected to a first source 22 of a first fluid via first conduit 23, and the second FTMV inlet 18 is fluidly connected to a second source 24 of a second fluid via second conduit 25. The second fluid has a greater temperature than the first fluid.

The STMV 14 has a first STMV inlet 26 and a second STMV inlet 28 as well as a STMV outlet 30. The second STMV inlet 28 is fluidly connected to the second source 24 of the second fluid via third conduit 27, which is connected to the second conduit upstream of the second FTMV inlet 18. At least one duct 32 fluidly connects the first STMV inlet 26 with the FTMV outlet 20. In particular, the at least one duct 32 is arranged to convey mixed fluid from the FTMV 12 to the STMV 14 for mixing therein with second fluid from the second fluid source.

As depicted, the at least one duct 32 may comprise first and second ducts 35, 36. The first duct 35 may fluidly connect the FTMV outlet 20 with at least one first fluid dispensing device. In particular and as shown, the first duct 35 may fluidly connect the FTMV outlet 20 with a shower 39, and a third conduit 33 connects a washbasin tap 38 with the first duct 35. The second duct 36 may be connected to the first duct 35 and convey fluid from the first duct to the first STMV inlet 26.

At least a fourth conduit 37 may fluidly connect the STMV outlet 30 with a bath tap 42, and a fifth conduit 43 may connect a kitchen sink tap 40 with the fourth conduit.

As shown, in the plumbing system 100, the second source 24 of second fluid may be a heat exchanger. The heat exchanger 24 is arranged to receive heat from a low temperature heat network 45, which may include a heat pump. In the depicted example, first fluid from the first source 22 is fed via heat pump conduit 48 to the heat exchanger 24 and passed therethrough so that the first fluid is heated to provide second fluid with a greater temperature than the first fluid.

In use, first fluid is fed to the first FTMV inlet 16 and second fluid is fed to the second FTMV inlet 18. The first and second fluids are then mixed inside the FTMV 12 to produce a first thermally mixed fluid. The first thermally mixed fluid is then fed from the FTMV outlet 20 to the first STMV inlet 26 of the STMV 14. The first thermally mixed fluid may also be fed to the shower 39 and/or washbasin tap 38 via the at least one duct 32.

The first thermally mixed fluid is mixed with second fluid in the STMV 14 to produce a second thermally mixed fluid. The second thermally mixed fluid is then fed to the kitchen sink tap 40 and/or the bath tap 42 from the STMV outlet 30.

In the invention, the FTMV outlet is fluidly connected with the first STMV inlet.

Therefore, in use, mixed fluid from the FTMV, which is associated with a lower temperature outlet (such as a shower or washbasin) is fed to the STMV, which is associated with a higher temperature outlet (such as a bath or kitchen sink). In this way, the temperature difference between flows of fluid entering the STMV is small. In other words, Delta Hot is larger relative to Delta Cold with respect to prior TMVs.

This means the position of the valve element in the STMV in normal operating conditions is closer to the hot seat of the STMV, meaning that the valve element can react more quickly to reduce the temperature of the mixed flow if there is a surge in hot water temperature, reducing the risk of scalding downstream.

The invention also means that there is an increased efficiency in systems where heat pumps are employed due to the small temperature difference.

The first fluid may be cold water, and the second fluid may be hot water.

The plumbing system described above may include a dedicated second fluid source. Alternatively, the first and second fluid sources may be fluidly connected and the second fluid may be first fluid which has been heated. For example, the second source of a second fluid may be a heat exchanger which receives water from the first source.

The first fluid may have a temperature, which is 25°C or less. Preferably, the first fluid has a temperature in the range of 4 to 25°C, and most preferably 20°C. The second fluid may have a temperature which is 40 °C or greater. Preferably, the second fluid has a temperature in the range of 40 to 70°C, and most preferably 50 to 60°C. This may mean that the first thermally mixed fluid has a temperature which is 35°C or greater when it leaves the FTMV outlet, and that in turn the second thermally mixed fluid has a temperature of 40°C or greater when it leaves the STMV outlet. Most preferably, the first thermally mixed fluid has a temperature of 44°C when it leaves the FTMV outlet and the second thermally mixed fluid has a temperature of 47°C when it leaves the STMV outlet.

The FTMV and STMV may each have a valve body and the valve bodies may be integrally formed, meaning the valve arrangement can be provided as a single integrated unit.

Modifications and improvements may be incorporated without departing from the scope of the invention, which is defined by the appended claims.

Claims

Claims 1 A valve arrangement comprising: a first thermostatic mixing valve (FTMV) having first and second FTMV inlets, and a FTMV outlet; and a second thermostatic mixing valve (STMV) having: first and second STMV inlets, and a STMV outlet; wherein the FTMV outlet is fluidly connected with the first STMV inlet.
2. The valve arrangement of claim 1, wherein the FTMV outlet is fluidly connectable to a first fluid dispensing device.
3 The valve arrangement of claim 1 or 2, wherein the FTMV comprises a FTMV valve body and the STMV comprises a STMV valve body, wherein the FTMV valve body and the STMV valve body are formed as one piece.
4 A plumbing system comprising: the valve arrangement of any preceding claim; a first source of a first fluid, the first source being fluidly connected with the first FTMV inlet; a second source of a second fluid with a greater temperature than the first fluid, the second source being fluidly connected with the second FTMV inlet and the second STMV inlet; and a first closable discharge outlet fluidly connected to the STMV outlet.
5. The plumbing system of claim 4, wherein the FTMV outlet is fluidly connected to a second closable discharge outlet.
6. The plumbing system of claim 5, wherein each of the first closable discharge outlet and second closable discharge outlet forms part of a shower or tap device.
7. The plumbing system of any of claims 4 to 6, further comprising a heat pump and a heat exchanger arranged to receive heat from the heat pump, whereinBthe second fluid of the second source comprises the first fluid from the first source passed through the heat exchanger.
8. The plumbing system of any of claims 4 to 7, wherein each of the first and second fluids is water.
9. The plumbing system of any of claims 4 to 8, wherein the temperature of the first fluid is 25 °C or less, wherein the temperature of the second fluid is 35 °C or greater.
A method of providing fluid to a discharge outlet, comprising: providing the valve arrangement of any of claims 1 to 3; connecting the first FTMV inlet to a first source of a first fluid and connecting the second FTMV inlet and second STMV inlet to a second source of a second fluid with a greater temperature than the first fluid; mixing, in the FTMV, the first fluid and the second fluid to produce a first thermally mixed fluid; conveying the first thermally mixed fluid to the STMV; mixing, in the STMV, the first thermally mixed fluid with the second fluid to produce a second thermally mixed fluid; and conveying the second thermally mixed fluid via the STMV outlet to the discharge outlet.
11. The method of claim 10, wherein the fluid is water.
12. The method of claim 10 or 11, wherein the temperature of the first fluid is 25 °C or less, wherein the temperature of the second fluid is 35 °C or greater.
13. The method of claim 12, wherein the temperature of the first thermally mixed fluid is 25°C or greater, wherein the temperature of the second thermally mixed fluid is 35°C or greater.