GB2528313A

GB2528313A - Fluid flow control apparatus for heating or cooling

Info

Publication number: GB2528313A
Application number: GB1412751.8A
Authority: GB
Inventors: Jan Oesterholm Hansen
Original assignee: SAV UNITED KINGDOM Ltd
Current assignee: SAV UNITED KINGDOM Ltd
Priority date: 2014-07-17
Filing date: 2014-07-17
Publication date: 2016-01-20
Anticipated expiration: 2034-07-17
Also published as: GB2528313B; GB201412751D0

Abstract

This invention is for a new fluid flow control apparatus that can be used in large buildings, such as offices or apartments to distribute fluid to a plurality of appliances. This may be used as part of a central heating system. There may be fan coils 1A, 1B, 1C and 1D that are connected to a respective controller 2A, 2B, 2C and 2D, which control the operation of the fan to regulate heat output. The fan coil units are supplied with hot water from a supply pipe 3 via flow control module 4. There are temperature sensors that measure the temperature of the fluid at both the inlet and outlet ports, as well as temperature sensors T1, T2, T3 and T4 that are associated with a respective return port for sensing the temperature of the fluid returning and providing a signal to an electrical control device 12.

Description

Fluid flow control apparatus for heating or cooling This invention relates to a fluid flow control apparatus for heating or oooling. The invention is particularly, but not exclusively, concerned with apparatus for distributing fluid to a plurality of appliances within a building, for example to separate offices or apartments in a building.

Such fluid flow control apparatus is known and is for example described in GB2416866B. In the system described therein, a control module is provided comprising an inlet port for conveying water into the module, a plurality of supply ports which supply water from the inlet port to a plurality of heat exchanger units, a plurality of return ports which receive water returning from the heat exchanger units and an outlet port for receiving water from the return ports. In one described embodiment the control module forms part of a Building Management System (BMS) and the control module includes electrically operated valves that control the supply of water to the heat exchanger units. The module has its own controllers but in addition is connected to a supervisory controller which may retrieve information from the module controllers and may override the module controllers as well as obtaining information from the module controllers. That information may include signals from temperature sensors associated with individual heat exchange units and temperature sensors recording the temperature of water fed into the module and water returned from the module. The signals from the temperature sensors associated with the individual heat exchanger units monitor temperatures of the spaces heated or cooled by the units and are used to control fans in those units and thereby control the temperatures in those spaces. Through signals from the water temperature sensors measuring the temperature of the water fed into the module and returned from the module, and from a flow measuring device that measures the overall flow to the module, the supervisory controller is able to measure the energy consumed by the heat exchanger units connected to the module. It is also possible to check the flow through a single heat exchanger unit by shutting off the flows to the other heat exchangers.

The fluid flow control apparatus of GB2416866B is very versatile and enables good monitoring of the fluid flow as well as measuring overall energy consumption. When the system is first set up, the flows to the individual heat exchanger units can be balanced so that there is more flow to some (larger) units than others and the valves on the module are adjusted accordingly. In this way the units can be set up to operate with a selected temperature change across them during normal use, that temperature change being one that provides efficient operation. For heating a temperature drop across a unit of about 20 degrees Celsius might be selected and for cooling a temperature increase of about 6 degrees Celsius might be chosen.

A problem can arise when there is a change in the demands made by the units. For example, in an office environment, there may be a change in tenant and/or a rearrangement of an office that leads to a different distribution of required outputs from the units. Another possibility is that a fault may develop in a unit, for example a fan in the unit may develop a fault. Thus a heat exchanger unit that previously was required to provide only a small output (a small amount of heating or cooling) and which was therefore set up to receive a relatively small flow, may in new circumstances be required to generate a greater output, or vice versa. That can mean that at some stage after initial set up the system operates much less efficiently.

It is an object of the invention to provide an improved form of fluid flow control apparatus.

According to the invention, there is provided a fluid flow control apparatus including a fluid flow control module comprising: an inlet port for conveying fluid into the fluid-flow control apparatus; a plurality of supply ports for supplying fluid conveyed from the inlet port to a plurality of fluid receiving units; a plurality of return ports for receiving fluid returning from the fluid receiving units; an outlet port for receiving fluid from the return ports and conveying fluid from the fluid-flow control apparatus; a temperature sensor for seusing the temperature of fluid at the inlet port; a temperature sensor for sensing the temperature of fluid at the outlet port; and a plurality of temperature sensors, each associated with a respective return port for sensing the temperature of fluid returning to the return ports and providing a signal to an electrical control device.

By providing temperature sensors for the individual return ports it becomes possible to monitor the temperature difference between the supply and return fluid for an individual fluid receiving unit. That makes it possible to be alerted to inefficient operation of any unit so that appropriate corrective action can be taken. furthermore such an alert can be provided without requiring access to the module or the heat exchanger units themselves.

Whilst it is within the scope of the invention for there to be only two supply and return ports, it will usually be the case that there are three or more supply ports and three or more return ports.

The supply ports of the module and/or the return ports of the module may be formed in a single manifold that is formed in one piece, for example as a casting.

The apparatus may further comprise a plurality of electrically controlled valves, each associated with a respective fluid path from a supply port, through a fluid receiving unit and back to a return port. Each electrically controlled valve is preferably able to effect a gradual adjustment of the fluid flow.

Each of the fluid paths from a supply port, through a fluid receiving unit and back to a return port may be further provided with a further valve for controlling the fluid flow. Fluid flow along each of the fluid paths from a supply port, through a fluid receiving unit and back to a return port may be controlled by a respective electrically controlled valve at the return port and a respective further valve at the supply port which may or may not be electrically controlled.

The invention is in a broad aspect directed to the control module per se. In use, the control module is connected to a plurality of fluid receiving units. Thus the fluid flow control apparatus may further include a plurality of fluid receiving units for receiving fluid supplied from respective supply ports and returning fluid to respective return ports.

The fluid receiving units may be heat exchanger units, for example fan coil units. Such units may be provided for heating and/or cooling.

Whilst the invention may be employed using a variety of fluids, most commonly and conveniently the fluid is water. The source of water will most commonly be a source of hot or chilled water. The temperature of the source may be naturally achieved or the water may be heated or cooled to the desire source temperature.

Respective local controllers may be associated with the fluid receiving units, the respective local controllers each being arranged for receiving an electrical signal input relating to temperature of a space to be heated and/or cooied by the fiuid receiving unit and for controlling the flow of fluid from and to the fluid flow control module. The electrical signal input may for example be provided by a thermostat in a space to be heated and/or cooled.

The apparatus may further include a fluid flow measuring device for measuring the overall fluid flow rate to the inlet port and/or from the outlet port. Such a measuring device may enable not only the overall fluid flow rate to be ascertained but may also enable the fluid flow rate to a single fluid receiving unit to be ascertained, for example by temporarily cutting off flow to all other units or by cutting off flow to the single unit and noting the change in overall flow rate.

The apparatus further includes a temperature sensor for sensing the temperature of fluid supplied to the inlet port of the control module. Such a sensor may effectively also indicate the temperature of the fluid supplied from the supply ports of the module since there may be no significant temperature drop between the inlet port to the module and the supply ports. This enables the temperature change between the supply and return ports of each individual unit to be monitored.

The apparatus further includes a temperature sensor for sensing the temperature of fluid at the outlet port of the control module. Such a sensor enables the temperature drop across the whole module to be monitored and that may provide further information about the efficiency of operation of the apparatus.

The fluid flow control apparatus referred to above may form part of a fluid flow control network which may for example control heating and/or cooling of spaces in an office building or one or more entire office buildings.

Thus the invention further provides a fluid flow control network comprising: a fluid flow control apparatus as defined above; and an electrical monitoring device for receiving signals from each of the temperature sensors.

The electrical monitoring device may be a part of a building management control system. The device may also be arranged to control one or more of the electrically controlled valves of the fluid flow control apparatus in a case where those are provided.

The invention still further provides a method of operating a fluid flow control apparatus as defined above.

The fluid flow through a given fluid receiving unit may be measured indirectly by measuring the overall flow to or from the fluid flow control module, operating one or more of the electrically controlled valves of the module and detecting the change In overall fluid flow to or from the fluid flow control module. The fluid flow through the given fluid receiving unit may be measured by closing the electrically controlled valve associated with the given fluid receiving unit and measuring the change in overall flow rate. Alternatively, the fluid flow through the given fluid receiving unit may be measured by closing the electrioaily controlied valves assooiated with ail the fluid receiving units apart from the given fluid receiving unit and measuring the overall flow rate.

The temperature sensors associated with the return ports of the fluid flow control module may also be used as fluid flow metering devices. For example, if a sensor detects a temperature close to ambient temperature at a return port, that may indicate a fault in the fluid receiving unit.

It will of course be appreciated that features described in relation to the method of the present invention may be incorporated into the apparatus of the invention and vice versa.

By way of example, an embodiment of the invention will now be described with reference to the accompanying drawing, of which: Fig. 1 is block diagram of a fluid flow control network in a Building Management System Fig. 1 shows a heating installation for part of a heating system for a building. The heating installation comprises four fan coil units 1A, 1B, 10 and 115, each having a respective controller 2A, 2B, 20 and 2D which controls the operation of the fan in the unit to regulate the heat output of the unit. The fan coil units are of a known design and are heat exchangers: they transfer heat from hot water passing through them to air which is then used for space heatiug. Typically each fan coil unit has an associated thermostat (not shown) which provides a signal to the associated controller 2A, 2B, 20 and 25.

Each of the fan coil units lA, 15, 10 and 1D is S supplied with hot water from a common supply pipe 3 via a flow control module 4. More particularly the flow control module 4 has an inlet port connected to the supply pipe 3 and four supply ports SA, SB, 50 and SD which supply hot water to respective fan coil units lA, 13, 10 and iD via respective electrically operated control valves 6A, 65, 60 and 65. After passing through the fan control units and losing heat in the units, the water returns to return ports of the module 4 along lines 7A, 73, 70 and 75 via respective return valves BA, 85, 80 and 819 (the connections between the fan coil units 1A, 15, 10 and 119 and the lines 7A, 73, 70 and 75 not being shown in Fig.1) . The return flows are combined in the module 4 and return from the module via a common return pipe 9.

If desired a bypass arrangement (not shown) may be provided in the module 4 to allow water to flow directly through the module from the supply pipe 3 to the return pipe 9 without passing through the fan coil units lA, 13, and 1D.

Also shown in Fig. 1 is a supervisory controller 12 which is connected to the controllers 2A, 23, 20 and 25, to the electrically operated control valves 6A, 63, 60 and 65 and to an energy meter 14 that measures the temperature of the overall return flow and, from that and a measurement of -10 -the overall flow rate, enables the supervisory controller to caloulate the energy consumed by the fan control units.

The arrangement as described above is similar to that shown in G32416866B.

In accordance with this embodiment of the invention, a special feature of the arrangement shown in Fig. 1 is the provision of a respective temperature sensor Ti, T2, T3 and T4 on each of the return lines 7A, 73, 70 and 7D shown in Fig.1. Electrical signals from each of those sensors are passed to the supervisory controller 12 which also receives a signal from a temperature sensor (not shown) measuring the temperature of the water supplied to the flow control module 4 along the supply pipe 3. Thus the supervisory controller 12 is informed of the individual temperature drops across each of the fan coil units 1A, 13, 10 and 13 and is alerted in the event that any of those temperature drops moves away from the desired level and therefore indicates that the fan coil unit is operating inefficiently. Furthermore that can be achieved without access to the control module 4. Tt is then possible to take appropriate corrective action and thereby maintain efficient operation, even when the demand on one particular heating circuit changes substantially, perhaps following a change of tenant and/or a rearrangement of the interior of a building.

The supervisory controller 12 is also able to make other uses of the signals from the temperature sensors Ti, T2, T3 and T4. For example, given that it can measure fluid -11 -flow through each fan coil unit separately, by cutting off flows and measuring the changes in overall flow rate, it can measure energy consumption of each individuai unit from that flow and the temperature drop across the unit. Also, the temperature sensors Ii, 12, P3 and 14 can act as individual fluid-flow metering elements; for example if there were a blockage in the flow through a fan coil unit, the temperature sensed in the return path from the unit would move away from any usual return temperature.

In the embodiment described above a heating installation has been described, but it should be understood that the invention can also be applied in substantially the same way to a cooling (air conditioning) installation and or to a combined heating and cooling installation.

In the illustrated embodiment, only one control module 4 associated with the supervisory controller 12 is shown but it should be understood that there may be a number of such modules, together forming a building management system that may control heating and/or cooling throughout a larger space, for example a floor of an office or the whole of a multi-storey office building.

Where in the foregoing description, integers or

elements are mentioned which have known, obvious or foreseeable eguivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as -12 -to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims.

Claims

-13 -Claims: 1. A fluid flow control apparatus inclilding a fluid flow control module comprising: an inlet port for conveying fluid into the fluid-flow control apparatus; a plurality of supply ports for supplying fluid conveyed from the inlet port to a plurality of fluid receiving units; a plurality of return ports or receiving fluid returning from the fluid receiving units; an outlet port for receiving fluid from the return ports and conveying fluid from the fluid-flaw control apparatus; a temperature sensor for sensing the temperature of fluid at the inlet port; a temperature sensor for sensing the temperature of fluid at the outlet port; and a plurality of temperature sensors, each associated with a respective return port for sensing the temperature of fluid returning to the return ports and providing a signal to an electrical control device.
2. An apparatus according to claim 1, in which there are three or more supply ports and three or more return ports.
3. Mi apparatus according to claim 1 or 2, further comprising a plurality of electrically controlled valves, each associated with a respective fluid path from a supply port, through a fluid receiving unit and back to a return port.

-14 -
4. Mi apparatus according to claim 3, in which each of the fluid paths from a supply port, through a fluid receiving unit and back to a return port is further provided with a further valve for controlling the fluid flow.
5. Mi apparatus according to claim 4, in which fluid flow along each of the fluid paths from a supply port, through a fluid receiving unit and back to a return port is controlled by a respective electrically controlled valve at the return port and a respective further valve at the supply port.
6. Mi apparatus according to any preceding claim, further including a plurality of fluid receiving units for receiving fluid supplied from respective supply ports and returning fluid to respective return ports.
7. Mi apparatus according to claim 6, in which the fluid receiving units are heat exchanger units.
8. Mi apparatus according to claim 6 or 7, in which the fluid receiving units are for heating.
9. Mi apparatus according to any of claims 6 to 8, in which the fluid receiving units are for cooling.
10. An apparatus according to any of claims 6 to 9, in which respective local controllers are associated with the fluid receiving units the respective local controllers each being arranged for receiving an electrical signal input relating to temperature of a space to be heated and/or cooled by the fluid receiving unit and for controlling the flow of fluid from and to the fluid flow control module.
11. An apparatus according to any preceding claim, further -15 -including a fluid flow measuring device for measuring the overall fluid flow rate to the inlet port and/or from the outlet port.
12. An apparatus substantially as herein described with S reference to Fig. 1 of the accompanying drawings.
13. A fluid flow control network comprising: a fluid flow control apparatus according to any preceding claim; and an electrical monitoring device for receiving signals from each of the temperature sensors.
14. A fluid flow control network according to claim 13, in which the electrical monitoring device is a part of a building management control system.
15. A method of operating a fluid flow control apparatus according to any of claims 1 to 12.
16. A method according to claim 15, in which the temperature of fluid supplied to the fluid receiving unit is measured by measuring the temperature of fluid supplied to the fluid flow control module.
17. A method according to claim 15 or 16, in which the apparatus is according to claim 3 and the fluid flow through a given fluid receiving unit is measured indirectly by measuring the overall flow to or from the fluid flow control module, operating one or more of the electrically controlled valves of the module and detecting the change in overall fluid flow to or from the fluid flow control module.
18. A method according to claim 17, in which the fluid -16 -flow through the given fluid receiving unit is measured by closing the electrically controlled valve associated with the given fluid receiving unit and measuring the change in overall flow rate.
19. A method according to claim 17, in which the fluid flow through the given fluid receiving unit is measured by closing the electrically controlled valves associated with all the fluid receiving units apart from the given fluid receiving unit and measuring the overall flow rate.
20. A method according to any of claims 15 to 19, in which the temperature sensors associated with the return ports of the fluid flow control module are also used as fluid flow metering devices.