EP4607110A1

EP4607110A1 - Heat pump and fluid distribution systems

Info

Publication number: EP4607110A1
Application number: EP24159622.0A
Authority: EP
Inventors: designation of the inventor has not yet been filed The
Original assignee: British Telecommunications PLC
Current assignee: British Telecommunications PLC
Priority date: 2024-02-26
Filing date: 2024-02-26
Publication date: 2025-08-27

Abstract

A heat pump system and fluid distribution system are provided. The heat pump system comprises a heat exchanger installed in proximity to a portion of a fluid distribution system such that it affects the temperature of the fluid with that portion of the fluid distribution system. The fluid distribution system delivers fluid from one or more sources to one or more end users via one or more pipes. The fluid distribution system comprises a temperature controller configured to: receive measurements of the temperature of the fluid at one or more locations within the fluid distribution system; analyse the measurements to determine whether remedial action needs to be taken to control the temperature of the fluid within the fluid distribution system; and transmit a control signal to the heat pump system in response to determining that remedial action needs to be taken. The heat pump system further comprises a controller configured to: receive the control signal; and control the operation of the heat pump system in accordance with the control signal so as to control an amount of heat transferred between a refrigerant fluid within the heat exchanger and the fluid distribution system.

Description

Field of the Invention

The present invention relates to a heat pump system and a fluid distribution system. In particular, it relates to a heat pump system that is arranged to transfer heat to a fluid in a portion of a fluid distribution system that is in proximity to the heat pump system.

Background to the Invention

There is a widespread and longstanding need for heating and/or cooling systems which can control the temperature of an environment inside a building. Industrial buildings, for example, may require cooling to remove the heat generated by manufacturing and/or operational processes. For example, the computer equipment running within a data centre will typically generate a large amount of heat that will need to be removed, via cooling, in order to keep the computer equipment running optimally. Failure to control the temperature may result in undesirable consequences, such as earlier failure of industrial machinery. For example, the computer equipment running within a data centre may experience a higher rate of failure if the temperature is not suitably controlled.
There are a wide range of climate control systems that have been developed in order to heat and/or cool an environment. One such system is a so-called heat pump. Heat pumps are devices that use energy to actively transfer heat from a first space (which may be referred to as a heat source) to a second space (which may be referred to as a heat sink). Where it is desired to use a heat pump to heat a target space, the heat pump can be configured with the target space as the heat sink, and another space as the heat source. Accordingly, in moving heat from the heat source to the heat sink, the heat pump will heat the target space and cool the other space. Conversely, where it is desired to use a heat pump to cool a target space, the heat pump can be configured with the target space as the heat source, and the other space as the heat sink. Accordingly, in moving heat from the heat source to the heat sink, the heat pump will cool the target space and heat the other space. Typically the other space with which heat is exchanged is the outside (or external) environment.
Internally, heat pumps make use of a refrigeration cycle to effect the heat transfer. During this refrigeration cycle, a refrigerant fluid will repeatedly cycle through the stages of compression, condensation, expansion and evaporation in turn, each of these stages being performed as the refrigerant fluid pass through a compressor, condenser, expander and evaporator respectively. Through changes in pressure of the refrigerant fluid during the compression and expansion phases of the cycle, the temperature of the refrigerant fluid is altered. Specifically, during the compression stage, as the refrigerant fluid passes through the compressor, the refrigerant fluid is compressed taking it from a low-pressure state to a high-pressure state. Accordingly, the temperature of the refrigerant fluid increases to a high-temperature. Conversely, during the expansion stage, as the refrigerant fluid passes through the expander, the refrigerant fluid is expanded taking it from a high-pressure state to a low-pressure state. Accordingly, the temperature of the refrigerant fluid drops to a low-temperature state. The condenser and evaporator are heat exchangers that function to exchange heat between the refrigerant fluid and the respective spaces in which they are located. The condenser receives the high-pressure, high-temperature refrigerant fluid from the compressor and allows the heat from the high-temperature refrigerant fluid to the be exchanged with the surrounding space (i.e. the heat sink) through the normal thermodynamic flow of heat from hot to cold. Accordingly, having passed through the condenser, the refrigerant fluid will have a lower temperature as a result of losing heat to the space in which the condenser is located. The space (heat sink) in which the condenser is located is heated by the heat received from the refrigerant fluid. Conversely, the evaporator receives the low-pressure, low-temperature refrigerant from the expander and allows heat from the surrounding space (i.e. the heat source) to be exchanged with the refrigerant fluid through the normal thermodynamic flow of heat from hot to cold. Accordingly, having passed through the evaporator, the refrigerant fluid will have a higher temperature as a result of gaining heat from the space in which the evaporator is located. The space (heat source) in which the evaporator is located is cooled by the removal of heat to the refrigerant fluid.
In some cases, heat pumps are reversible, meaning that they can be run to transfer heat in either direction. That is to say, they may transfer heat to a target space from another space in order to heat the target space or they may run in reverse and transfer heat from the target space to the other space in order to cool the target space. Accordingly, the heat exchangers that are arranged to transfer heat between the refrigerant fluid of the heat pump and each of the spaces may operate as either condenser or expander depending on which direction the heat pump is transferring heat.
Commonly, where a large amount of heating and/or cooling is required the external heat exchanger of the heat pump (that is, the one that exchanges heat with a space other than the target space) will be configured to exchange heat directly with the ground of the other space that is acting as the heat source and/or sink. This is because the ground has a large thermal mass which means that it is capable of having a large amount of heat extracted or deposited before its temperature will be significantly changed. Such a ground source heat exchanger essentially consists of pipework running within the ground in the other space through which the refrigerant fluid is run. This pipework may also be referred to as a ground array. There are a variety of different pipework patterns that may be used for this, as will be familiar to the skilled person, including running pipes vertically, or horizontally within the ground. The size of such ground source heat exchangers (e.g. the amount of pipework and the area of ground covered) dictates the amount of heating or cooling that can be accommodated by the heat pump system.
Another technique that may be used to provide cooling in industrial buildings (or indeed any other type of building) is evaporative or adiabatic cooling. However, this requires a supply of water that can be consumed as part of the cooling process.

Summary of the invention

The size of ground array that is needed to provide adequate heating and/or cooling may, in some cases, be prohibitively large. This may be, for example, due to there being insufficient amount of ground around a building available for the ground array to be installed horizontally. Meanwhile, installing the ground array pipework vertically may be overly expensive or impractical. It would therefore be desirable to enhance the heating or cooling capacity of a ground source heat pump in such situations.
In a first aspect of the present invention, there is provided a heat pump system comprising: a heat exchanger installed in proximity to a portion of a fluid distribution system; a controller configured to: receive a control signal from a temperature controller of the fluid distribution system; and control the operation of the heat pump system in accordance with the control signal so as to control or limit an amount of heat transferred between a refrigerant fluid within the heat exchanger and the fluid distribution system.
The heat pump system takes advantage of the thermal capacity of a fluid distribution system installed in proximity to the external heat exchanger (or ground array) of the heat pump system to enhance the heat transfer capabilities of the system. In particular, the heat pump system can transfer heat to a fluid flowing within the fluid distribution system. As the fluid flows within the fluid distribution system, it moves through the heat pump's area of operation during which heat may be transferred between the fluid and heat pump system. The fluid then flows onward through the fluid distribution system to an end user of the fluid distribution system. In order to prevent excessive heating or cooling of the fluid within the fluid distribution system which might prevent the fluid from being usable by the end users of the fluid distribution system, the heat pump system communicates with a temperature controller of the fluid distribution system to adjust its operation as appropriate to maintain the fluid within the fluid distribution system within a desired temperature range.
The heat pump system may further comprise a temperature sensor for determining the temperature of the fluid within the fluid distribution system proximate to the heat pump system, wherein the heat pump system is further configured to provide measurements from the temperature sensor to the temperature controller of the fluid distribution system.
In a second aspect of the present invention, there is provided a fluid distribution system for delivering fluid from one or more sources to one or more end users via one or more pipes, the fluid distribution system comprising: a temperature controller configured to: receive measurements of the temperature of the fluid at one or more locations within the fluid distribution system; analyse the measurements to determine whether remedial action needs to be taken to control the temperature of the fluid within the fluid distribution system; and transmit a control signal to a heat pump system in response to determining that remedial action needs to be taken, the heat pump system affecting the temperature of the fluid within a portion of the fluid distribution system in proximity to the heat pump system through the transfer of heat between the heat pump system and the fluid distribution system, the control signal controlling the operation of the heat pump system.
The fluid distribution system may further comprise a flow control device that is configured to control the flow of the fluid within the fluid distribution system, wherein the temperature controller is further configured to transmit a control signal to the flow control device to control the temperature of the fluid within the fluid distribution system.
The one or more pipes of the fluid distribution system may define a loop within the fluid distribution system, the heat pump system affecting the temperature of the fluid flowing through at least a portion of the loop; and the flow control device may control a rate of flow of fluid around the loop.
The one or more pipes of the fluid distribution system may define one or more parallel branches for fluid to flow within the fluid distribution system, the heat pump system affecting the temperature of the fluid flowing through at least a portion of one of the parallel branches; and the flow control device may control the proportion of fluid flowing through each of the parallel branches.
The fluid distribution system may further comprise one or more temperature sensors, each temperature sensor being configured to measure a temperature of the fluid at a respective location inside the fluid distribution system and provide those measurements to the temperature controller.
The temperature controller may receive measurements of the temperature of the fluid at a plurality of locations within the fluid distribution system and is further configured to determine an amount of heat being exchanged with the fluid within different parts of the fluid distribution system.
The temperature controller may be further configured to transmit a respective control signal to each of one or more further heat pump systems in response to determining that remedial action needs to be taken, the one or more further heat pump systems each affecting the temperature of the fluid within a respective portion of the fluid distribution system in proximity to that heat pump system through the transfer of heat between that heat pump system and the fluid distribution system, each of the further heat pump systems being fluidically isolated from the fluid distribution system, each control signal controlling or limiting the operation of the respective heat pump to which it is transmitted.
The respective control signals sent to the one or more further heat pump systems may control the operation of those one or more further heat pump systems to at least partially counteract the effect of the heat pump system on the temperature of the fluid within the fluid distribution system.
The fluid distribution system may be a water distribution system for delivering water from one or more water sources to one or more end users, preferably wherein the water is potable water.
The fluid distribution system may deliver fluid to a plurality of end users, preferably more than 500,000 end users.
The fluid distribution system may deliver fluid over a large geographical area, preferably more than 1,000 km².
The heat pump system may be configured to regulate the temperature within a data centre.
The heat pump system may be a ground source heat pump system that is configured to transfer heat energy to or from a portion of the fluid distribution system indirectly by transferring heat energy with the ground in proximity to the portion of the fluid distribution system.

Brief Description of the Figures

Embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings, in which:

Figure 1A is a diagrammatic representation of an aerial view of an exemplary heat pump system according to embodiments of the invention.
Figure 1B provides a cross sectional view of the exemplary heat pump system represented in figure 1A.
Figure 2 is a diagrammatic representation of an exemplary fluid distribution system according to embodiments of the invention.
Figure 3 is a diagrammatic representation of another exemplary fluid distribution system according to embodiments of the invention.

Detailed Description of Embodiments

Figure 1A is a diagrammatic representation of an aerial view of an exemplary heat pump system 100 according to embodiments of the invention. Figure 1B provides a cross sectional view of the exemplary heat pump system 100 represented in figure 1A.
The heat pump system 100 comprises a heat pump 110, a controller 115, an external heat exchanger 130 and an internal heat exchanger 135. The heat pump 110 comprises a compressor, an expander and a pump (not shown) for causing a refrigerant fluid to circulate through the compressor, expander, external heat exchanger 130 and internal heat exchanger 135 to undergo a refrigeration cycle (as described above) and transfer heat between an internal space within a building 120 in respect of which the internal heat exchanger 135 is installed and an external space in which the external heat exchanger 130 is installed.
In this example, the building 120 in respect of which the heat pump system 100 is installed may be an industrial building, such as a data centre, and the heat pump system 100 may be configured to regulate the temperature of the internal space within that building by cooling the internal space to remove heat generated by the computer equipment within the data centre. However, it will be appreciated that the heat pump system 100 may be installed to regulate the temperate of the internal space of any kind of building by heating and/or cooling the internal space.
The external heat exchanger 130 is installed in proximity to a portion 140 of a fluid distribution system, such that heat may be transferred between the refrigerant fluid flowing within the external heat exchanger 130 and a fluid flowing within the fluid distribution system. In some cases, as shown in figures 1A and 1B, the external heat exchanger 130 may comprise a conventional ground array installed close to the nearby portion 140 of the fluid distribution system. Accordingly, the heat pump system 100 may be considered to be a ground source heat pump system. In such cases, the transfer of heat between the heat pump system 100 and the fluid within the nearby portion 140 of the fluid distribution system may be indirect. That is to say, the heat pump system 100 transfers heat with the intervening ground between the external heat exchanger 130 and the nearby portion 140 of the fluid distribution system which in turn exchanges heat with the fluid within the fluid distribution system. For example, where the heat pump system 100 is being used to heat the internal space within the building 120, heat may be taken from the ground in proximity to the portion 140 of the fluid distribution system by the external heat exchanger 130. This results in the temperature of the ground dropping, such that heat from the fluid within the water distribution system flowing within that portion 140 may in turn be transferred to the ground in proximity to that portion 140 through the conventional action of thermodynamic heat transfer. As can be seen in figure 1B, there is a separation between the portion 140 of the fluid distribution system and the pipework of the external heat exchanger 130.
It will be appreciated that the heat pump system 100 shown in figures 1A and 1B is merely exemplary for the purposes of explaining the invention. Various adaptations to the system will be readily apparent to the skilled person. For example, in some adaptations, the external heat exchanger 130 may be directly coupled to the portion 140 of the fluid distribution system. Accordingly, in such adaptations, heat may be transferred substantially directly (or at least without the ground acting as an intermediary) between the refrigerant fluid within the external heat exchanger 130 and the fluid within the portion 140 of the fluid distribution system. Indeed, in some such adaptations, the portion 140 of the fluid distribution system and the external heat exchanger 130 may be located above ground, rather than under ground as shown in figures 1A and 1B. Of course, it will be appreciated that even where the external heat exchanger 130 is directly coupled to the nearby portion 140 of the fluid distribution system, fluidic isolation between the fluid within the portion 140 of the fluid distribution system and the refrigerant fluid within the external heat exchanger 130 is still maintained. That is to say, there is no fluid exchange that takes place between the heat pump system 100 and the fluid distribution system.
The heat pump system 100 will now be discussed further in conjunction with figure 2 which is a diagrammatic representation of an exemplary fluid distribution system 200 (or network) according to embodiments of the invention. The fluid distribution system 200 is arranged to deliver fluid from one or more sources 210 to one or more end users 220 via one or more pipes 230. As discussed above, the heat pump system 100 is installed such that the external heat exchanger 130 of the heat pump system 100 is in proximity to a portion 140 of the fluid distribution system 200. Although, for simplicity, only a single heat pump system 100 is shown as being present in the vicinity of the pipes 230 of the fluid distribution system 200 shown in figure 2, it will be appreciated that in some cases many such heat pump systems 100 may make use of the same fluid distribution system 200 (each at a respective different location within the distribution system) to enhance their cooling and/or heating capacity through the transfer of heat with the fluid within the fluid distribution system (that is in proximity to their respective locations). In some cases, therefore, one or more further heat pump systems may also make use of the fluid distribution system 200 in the manner described herein.
In the example shown in figure 2, the fluid distribution system 200 is a water distribution system for delivering water (preferably, though not necessarily, potable water) from one or more water sources 210 to the end users 220. The sources 210 for such a water distribution system may include a reservoir, or other body of water, from which water may be taken. As will be familiar to those skilled in the art, the water may be treated by a water treatment plant 240 before reaching the end users 220 (although this may not be necessary in all cases). Although not shown in figure 2, various other plant may be included in fluid distribution system 200 as will be familiar to those skilled in the art. For example, the fluid distribution system 200 may include various pumping plant at one or more locations to move the fluid through the distribution system 200 to the end users 220. Of course, it will be appreciated that the invention may also be applied to other types of fluid distribution systems that are involved in the transport of other types of fluid other than water.
The building 120 in respect of which the heat pump system 100 is installed may itself also be an end user 220 of the fluid distribution system 200. That is to say, the fluid distribution system 200 may be used both to facilitate the heating and/or cooling of the building 120 as well as to deliver fluid from the source to the building 120 for consumption by the occupants and/or systems within that building. Of course, it will be appreciated that even where this is the case, the fluidic isolation between the heat pump system 100 and the fluid distribution system 200 is still maintained.
The fluid distribution system 200 comprises a temperature controller 250. The temperature controller 250 is communicatively coupled to the heat pump system 100 via one or more networks 260. Any suitable type of network(s) may be used to enable the temperature controller 260 to communicate with the heat pump system(s) 100, including, for example, the Internet. In the exemplary fluid distribution system 200 illustrated in figure 2, the temperature controller 250 is housed within the infrastructure 260 of the fluid distribution system 200, such as at the water treatment plant 240. However, this need not be the case and, in other examples, the temperature controller 250 may be located elsewhere, such as in cloud computing infrastructure.
The temperature controller 250 is configured to receive measurements of the temperature of the fluid at one or more locations within the fluid distribution system 200. These measurements may be received via the network 260 (although, in some cases, the measurements may be received via a different network from that which is used to communicate with the heat pump system 100). The fluid distribution system 200 may, for example, comprise one or more temperature sensors 270 at various locations within distribution system 200. These temperature sensors 270 may be located internally within the pipework 230 of the fluid distribution system or otherwise thermally coupled to the pipework 230 to allow the temperature of the fluid to be determined. Additionally, or alternatively, the temperature measurements may be received from the heat pump system(s) 100. That is to say, the heat pump system 100 may comprise a temperature sensor (not shown in figure 1) for determining the temperature of the fluid within the portion 140 of the fluid distribution system 200 proximate to the heat pump system 100. The heat pump system 100 may transmit measurements from that temperature sensor to the temperature controller 250 via the network(s) 260.
Although figure 2 shows just two temperature sensors 270, it will be appreciated that any number of temperature sensors 270 may be used. In the simplest case, a single temperature sensor may suffice. However, generally it is expected that a plurality of temperature sensors 270 will be used. Ideally (though not necessarily), the fluid distribution system 200 would comprise a sufficient number of temperature sensors 270 (or receive measurements from temperature sensors embedded in the heat pump systems 100 utilising the fluid distribution system 200 in accordance with embodiments of the invention) to enable a temperature of the fluid immediately before and after each heat pump system 100 to be determined. This can allow the individual heating effect of each heat pump system 100 on the fluid distribution system to be determined in a straightforward manner.
The temperature controller 250 analyses the received measurements to determine whether remedial action needs to be taken to control the temperature of the fluid within the fluid distribution system 200. As will be appreciated, it may be desirable to maintain the temperature of the fluid within the fluid distribution system 200 within a certain predetermined range. There may be a variety of reasons for maintaining the temperature of the fluid within this range, including, for example, safety concerns, operational concerns for the fluid distribution system 200 and/or concerns for maintaining the usability of the fluid for the end users 220. In some cases, the temperature controller 250 may operate in a reactive manner. That is to say, it may determine whether the measured temperature at any point in the distribution system 200 exceeds a predetermined threshold and, if so, determine that remedial action needs to be taken. This predetermined threshold may be set at a level within the predetermined range to allow for the reaction time of the system 200 so as to prevent the predetermined range be exceeded. In some cases, the temperature controller 250 may operate in a proactive manner. That is to say, the temperature controller 250 may use the measurements to predict whether (and when) the temperature of the fluid will exceed the predetermined range in the future. For example, various machine learning techniques may be used to train a machine learning model to predict whether the temperature of the fluid will breach the predetermined range.
In some cases, the temperature controller 250 may also use the measurements of the temperature of the fluid received from a plurality of locations within the fluid distribution system 200 to determine an amount of heat being exchanged with the fluid within different parts of the fluid distribution system 200. In particular, the temperature controller may determine a difference in temperature from the measurements received from pairs of temperature sensors 270 and may use the flow rate of the fluid flowing between those temperature sensors 270 to determine an amount of heat energy that has been transferred to or from the fluid in the space between those temperature sensors 270. The data derived from this analysis may be referred to herein as heat transfer data. This heat transfer data can be used for a variety of purposes. For example, by building up historical data of the heat transferred to or from the fluid within different parts of the fluid distribution system 200 over a number of time periods, this information may be used to predict future demand for heating or cooling by the heat pump systems 100 that are utilising the fluid distribution system 200. For example, the heat transfer data for the historical time periods may be used to train a machine learning model to predict future heat transfer requirements for each part of the fluid distribution system. These predictions may then be used by the temperature controller 250 to help control the temperature of the fluid within the fluid distribution system to account for these future heat transfer requirements. Of course, this heat transfer data may be useful for other purposes, such as providing an account of the usage that is being made of the fluid distribution system 200 by each heat pump system 100. Nonetheless, despite the usefulness of such data, it is not necessary for temperature controller 250 to produce heat transfer data and in some cases, control of the temperature of the fluid within the fluid distribution system 200 is performed without explicitly determining the amount of heat being exchanged with the fluid within different parts of the fluid distribution system 200.
Where it is determined that remedial action needs to be taken, the temperature controller 250 transmits a control signal to the heat pump system 100 in order to carry out the remedial action. The control signal is transmitted to the heat pump system 100 via the network(s) 260. The control signal is received by a controller 115 of the heat pump system 100. The control signal instructs the controller 115 of the heat pump system 100 to control or limit an amount of heat that will be transferred to the fluid distribution system 200 during operation of the heat pump. That is to say, the control signal indicates either a specific amount of heat to be transferred or a limit on the amount of heat that can be transferred between the refrigerant fluid within the external heat exchanger 130 of the heat pump system and the portion 140 of the fluid distribution system 200 that is in proximity to the external heat exchanger 130 of the heat pump system 100. The controller 115 is configured to operate the heat pump system 100 in accordance with any such control signals that have been received from the temperature controller 250 of the fluid distribution system 200. Specifically, where a control signal is received from the temperature controller 250 of the fluid distribution system 200 to control the specific amount (or rate) of heat transferred between the external heat exchanger 130 of the heat pump system 100 and the fluid within the nearby portion 140 of the fluid distribution system, the controller 115 of the heat pump system 100 controls the rate of the operation of the heat pump system to achieve (as closely as possible) that specified amount (or rate) of heat transfer. Similarly, where a control signal is received from the temperature controller 250 of the fluid distribution system 200 to limit the amount (or rate) of heat transferred between the external heat exchanger 130 of the heat pump system and the fluid within the nearby portion 140 of the fluid distribution system, the controller 115 of the heat pump system 100 controls the rate of the operation of the heat pump system 100 to ensure that that specified amount (or rate) of heat transfer is not exceeded. This enables the heat pump system 100 to maintain a degree of autonomy over the operation of the heat pump system 100 whilst allowing the temperature controller 250 of the fluid distribution system 200 sufficient control to regulate the temperature of the fluid within the fluid distribution system 200.
The limit specified in the control signal may be a limit on the amount (or rate) of heat transferred by the heat pump system 100 to the fluid within the fluid distribution system 200 (in those cases where the heat pump system 100 is configured to cool the building 120 in respect of which it is installed), in which case the controller 115 controls the operation of the heat pump system 100 to ensure that no more than that amount (or rate) of heat is transferred to the fluid by the heat pump system 100. Similarly, the limit specified in the control signal may be a limit on the amount (or rate) of heat transferred by the heat pump system 100 from the fluid within the fluid distribution system 200 (i.e. where the heat pump system 100 is configured to heat the building 120 in respect of which it is installed), in which case the controller 115 controls the operation of the heat pump system 100 to ensure that no more than that amount (or rate) of heat is transferred from the fluid by the heat pump system 100. In some cases, respective limits may be provided for both the amount (or rate) of heat that can be transferred to the fluid by the heat pump system 100 and the amount (or rate) of heat that can be transferred from the fluid by the heat pump system 100. This can allow the controller 115 to control the operation of the heat pump system 100 according to the relevant limit depending on which mode (i.e. heating or cooling building 120) it is operating in.
In some cases, the limit specified in the control signal may comprise an upper and lower limit on the amount (or rate) of heat that is transferred with the heat pump system 100 to the fluid within the fluid distribution system 200. In such cases, the controller 115 may control the operation of the heat pump system 100 to ensure that the amount (or rate) of heat transferred by the heat pump system 100 to the fluid in the portion 140 of the fluid distribution system in proximity to the heat pump system 100 neither exceeds the upper limit nor falls below the lower limit.
The operation of all heat pump systems that are utilising the fluid distribution system 200 in this manner may be individually controlled by the temperature controller 250. That is to say, the temperature controller 250 can send respective control signals to each of the heat pump systems via the network(s) 260 to individually control or limit their operation in order to regulate the temperature of the fluid within the fluid distribution system 200. Indeed, where multiple heat pump systems are utilising the fluid distribution system 200 for opposite purposes (that is to say where some heat pump systems are providing heating utilising the fluid distribution system whilst other heat pump systems are utilising the fluid distribution system to provide cooling), it may be possible to control or limit the operation of the heat pump systems such that the operation of at least some of the heat pump systems counterbalances (or counteracts) the effect of one or more other of the heat pump systems. For example, where the operation of a heat pump system, such as the heat pump system 100, results in the temperature of the fluid in the fluid distribution system 200 increasing (i.e. due to the heat pump cooling the building 120 by transferring heat to the fluid), the operation of one or more other heat pump systems that are using the fluid in the fluid distribution system 200 for heating may be increased (either by directly controlling those heat pump systems to increase their operations or by setting a limit on their operation that permits the respective controllers of those heat pump systems to increase their operations as appropriate), thereby removing some or all of the heat from the fluid that was added by the heat pump system 100.
In determining what control signals should be sent to carry out the remedial action to maintain the temperature of the fluid within the desired range, the temperature controller 250 may determine what the available heat transfer capacity is for each heat pump system utilising the fluid distribution system 200. That is, how much (or what rate) of heat may be transferred to or from the fluid within the respective portion 140 of the fluid distribution system 100 proximate to each heat pump system whilst still allowing the temperature of the fluid to remain within the desired range. As will be understood by those skilled in the art, this heat transfer capacity may be determined from the flow rate of the fluid through that portion and the temperature difference between the upper and/or lower bound of the desired temperature range (depending on whether heating or cooling is being carried out by that heat pump system 100). The remedial action may therefore be to set (or limit) each heat pump system 100 at a level which does not exceed the respective amount of heat transfer capacity that has been determined for the portion 140 of the fluid distribution system in proximity to that heat pump system 100. In some cases, the control signals may be programmatically determined from a set of predetermined rules for the fluid distribution system 200. However, in other cases, a suitable machine learning technique may be employed to learn the characteristics of the heat transfer capacities of the portion(s) of the fluid distribution system 200 proximate to heat pump systems relative to the flow rates and the measured temperatures. Indeed, in some such cases, suitable machine learning techniques may also be used to determine what action(s) should be taken. That is to say, what limits should be set for each of the heat pump system(s) utilising the fluid distribution system 200 in order to optimally maintain the temperature of the fluid within the distribution system 200 within the desired range. For example, a neural network may be trained to predict a temperature change that will occur in each part of the neural network as a result of setting (or limiting) the operation of each heat pump system at various levels given the current temperatures and flow rates within the system 200. Of course, other variables may be used as inputs for the neural network, such as time of day, as will be apparent to those skilled in the art. Similarly, reinforcement learning may be used to train an autonomous agent to take actions (i.e. issue control signals) to control the temperature within the distribution system 200. During training, the autonomous agent may be rewarded based on whether the temperature of the fluid within the distribution system 200 stays within the desired range (and penalised if the temperature of the fluid exceeds the desired range). This reward may be further adjusted based on the amount of overall heat transfer capacity (both heating and cooling) that is made available to the heat pump systems 100 utilising the fluid distribution system 200.
Figure 3 is a diagrammatic representation of another exemplary fluid distribution system 300 according to embodiments of the invention. The fluid distribution system 300 shown in figure 3 is the same as that shown in figure 2, with the exception that the external heat exchanger 130 is situated on a branch 310 of the water distribution network 300. The fluid distribution system 300 shown in figure 3 additionally comprises a flow control device 320 that is configured to control the flow of the fluid within the fluid distribution system. In particular, the flow control device 320 controls what proportion of the fluid flows within the branch 310 used by the heat pump system 100 as compared to the main branch 330. As will be appreciated, overall flow through the fluid distribution system 300 may be variable, being dependent on the consumption of the fluid by the end users 220. However, by altering the flow through different paths in the distribution system 300, such as between branches 310 and 330, a flow rate through one of the branches can be kept more consistent than would otherwise be the case. This more consistent flow is beneficial to any heat pump systems 100 that are utilising that branch 310 of the fluid distribution system 300 for the transfer of heat as it provides a more consistent heat transfer capacity for the heat pump system 100 to use. This in turn may allow the heat pump system 100 to be designed in a manner that relies more on the availability of that heat transfer capacity (e.g. by further reducing the size of the external heat exchanger 130).
The flow control device 320 is communicatively coupled to the temperature controller 240 of the fluid distribution system 300 via the one or more networks 260 (again, this may be the same or different network(s) as those used to communicate between the temperature controller 240 and the temperature sensors 270 and/or heat pump system 100). The flow control device 320 may be controlled by the temperature controller 240. That is to say, the temperature controller 240 may transmit a control signal to the flow control device 320 via the network(s) 260 in order to adjust the relative flow of fluid between the parallel branches 310 and 330 within the fluid distribution system 300. As will be appreciated, adjusting the flow rate within a branch 310, the heat transfer capacity of that branch will be correspondingly adjusted. For example, increasing the flow rate within a branch 310 will increase the heat transfer capacity of that branch 310. This in turn will affect the degree to which the action of a heat pump system 100 that is utilising that branch 310 for heat transfer will alter the temperature of the fluid within that branch 310. For example, where the heat transfer capacity of that branch 310 is increased (by increasing the flow rate within that branch 310), the same amount of heat transferred by the heat pump system 100 will result in a lower change in temperature to the fluid within the fluid distribution system 300. Accordingly, the temperature controller 240 can use the flow control device 320 to control the temperature of the fluid within the fluid distribution system 300 by controlling the proportion of fluid flowing through each of the parallel branches 310 and 320.
As an alternative (or in addition) to the use of parallel branches 310 and 320, the fluid distribution system 300 may make use of flow loops within the fluid distribution system 300. That is to say, one or more of the pipes 230 of the system 300 may form a loop that allows the fluid to circulate within the fluid distribution system 300 (even in the absence of consumption of the fluid by the end users 220). A flow control device (such as a pump) may be included in the fluid distribution system 300 to control the rate of flow of the fluid around the loop within the system 300. Again, this flow control device (and therefore the rate of flow of the fluid around the loop) may be controlled by the temperature controller 240 of the fluid distribution system 300 through the transmission of control signals via the network(s) 260. As for the parallel branches discussed above, adjusting the flow rate within the loop will adjust the heat transfer capacity of the fluid within the loop. That is to say, a particular amount (or rate) of heat exchanged between the heat pump system 100 and the fluid within the loop will result in a different temperature change in the fluid dependent on the flow rate. As will be appreciated, as the fluid circulates around the loop, the overall temperature of the fluid may increase each time it circulates. In particular, if the heat exchanged between the fluid and the ground (or with other heat pump systems with external heat exchangers in proximity to the loop) as it circulates throughout the remainder of the loop that is not affected by the heat pump system 100 does not entirely counterbalance the heat exchanged with the heat pump system 100 in the portion of the loop that is proximate to the external heat exchanger 130 of the heat pump system 100, then the temperature of the fluid will gradually change over time. Of course, the longer the loop, the less likely this is to happen because the fluid has longer to replace or release the heat (depending on whether the heat pump system 100 is operating to heat or cool the building 120) with the ground outside of the area covered by the external heat exchanger 130 of the heat pump system 100. Furthermore, it will be appreciated that the fluid circulating within the loop may be replaced with fresh fluid (that is fluid that has not yet experienced any heat exchange with the heat pump system 100) as the end users 220 consume the fluid from the system. The recirculation of the fluid around the loop may be performed to improve or maintain the heat transfer capacity of the fluid within the loop during times when the overall flow of fluid through the system 300 is reduced (e.g. due to the consumption of the fluid by the end users 220 being less than average or even zero).
In some cases, the branch or loop on which the heat pump system 100 is located may be added to the fluid distribution system 300 specifically for the purposes of enhancing the heating and/or cooling capacity of that heat pump system 100. That is to say, the branch or loop may be dedicated for heating and/or cooling and may not be required for the delivery of fluid to end users 220 such that no fluid leaves the fluid distribution system from the branch or loop (at last initially at the time of its installation). Of course, this need not be the case and, in other cases, the external heat exchanger 130 of the heat pump system 100 may be installed in proximity to an existing (or non-dedicated) pipe 230 of the fluid distribution system 200.
The option to adjust the heat transfer capacity of the fluid within the portions 140 of the fluid distribution system 200 that are proximate to a heat pump system 100 by adjusting the flow rates of the fluid through that portion 140 may be taken into account by the temperature controller 140 when determining what remedial action to take. For example, rather than lowering a limit on the operation of a heat pump system 100 by issuing a control signal to that heat pump system 100, the flow rate of the fluid through the portion 140 of the fluid distribution system 200 proximate to that heat pump system 100 may instead be increased by issuing a control signal to the flow control device 320 instead. Of course, in some cases, a combination of control signals may be issued to adjust both the operation of the heat pump system 100 and the flow control device 320. For example, the flow rate of the fluid through the portion 140 of the fluid distribution system 300 proximate to the heat pump system 100 may be increased and the limit on the operation of the heat pump system may be lowered, albeit to a lesser extent than would otherwise be the case. Where reinforcement learning is used to teach an autonomous agent to take remedial actions to maintain the temperature of the fluid in the distribution system 300 within the desired range, the option to control the flow rates of the flow control device(s) in the network may be included in the set of actions that are available to the autonomous agent being trained, as will be appreciated by those skilled in the art.
It will be appreciated that the size and complexity of the fluid distribution systems 200 and 300 discussed above in relation to figures 2 and 3 has been kept small and simple for the purposes of explaining the operation of the invention. It is anticipated (though not necessary) that the fluid distribution systems embodying the invention (and with which heat pump systems according to other embodiments of the invention may be used) will be large. In particular, it is anticipated that the fluid distribution systems embodying the invention will serve a relatively large number of end users 220, such as more than 500,000 end users 220. Similarly, the fluid distribution systems embodying the invention are anticipated to cover a relatively large geographical area, such as areas of more than 1,000 km². With such sizes of distribution systems it is generally expected that the complexity of the systems will also increase. Nonetheless, this does not affect the general operation of the invention as described herein. Indeed, to the contrary, larger distribution systems may be able to provide a flow rate of fluid which is both greater in magnitude and less variable in nature. This greater, less variable, flow rate may enhance the benefit provided to heat pump systems according to embodiments of the invention by providing a greater more reliable heat transfer capacity.
It will be understood by those skilled in the art that, although the present invention has been described in relation to the above-described example embodiments, the invention is not limited thereto and that there are many possible variations and modifications which fall within the scope of the invention. The scope of the present invention includes any novel features or combination of features disclosed herein. The applicant hereby gives notice that new claims may be formulated to such features or combination of features during prosecution of this application or of any such further applications derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in the specific combinations enumerated in the claims.

Claims

A heat pump system comprising:
a heat exchanger installed in proximity to a portion of a fluid distribution system;

a controller configured to:
receive a control signal from a temperature controller of the fluid distribution system; and

control the operation of the heat pump system in accordance with the control signal so as to control an amount of heat transferred between a refrigerant fluid within the heat exchanger and the fluid distribution system.
The system of claim 1, wherein the heat pump system further comprises a temperature sensor for determining the temperature of the fluid within the fluid distribution system proximate to the heat pump system, wherein the heat pump system is further configured to provide measurements from the temperature sensor to the temperature controller of the fluid distribution system.
A fluid distribution system for delivering fluid from one or more sources to one or more end users via one or more pipes, the fluid distribution system comprising:
a temperature controller configured to:
receive measurements of the temperature of the fluid at one or more locations within the fluid distribution system;

analyse the measurements to determine whether remedial action needs to be taken to control the temperature of the fluid within the fluid distribution system; and

transmit a control signal to a heat pump system in response to determining that remedial action needs to be taken, the heat pump system affecting the temperature of the fluid within a portion of the fluid distribution system in proximity to the heat pump system through the transfer of heat between the heat pump system and the fluid distribution system, the control signal controlling the operation of the heat pump system.
The system of claim 3 further comprising a flow control device that is configured to control the flow of the fluid within the fluid distribution system, wherein the temperature controller is further configured to transmit a control signal to the flow control device to control the temperature of the fluid within the fluid distribution system.
The system of claim 4, wherein:
the one or more pipes define a loop within the fluid distribution system, the heat pump system affecting the temperature of the fluid flowing through at least a portion of the loop; and

the flow control device controls a rate of flow of fluid around the loop.
The system of claim 4 or claim 5, wherein:
the one or more pipes define one or more parallel branches for fluid to flow within the fluid distribution system, the heat pump system affecting the temperature of the fluid flowing through at least a portion of one of the parallel branches; and

the flow control device controls the proportion of fluid flowing through each of the parallel branches.
The system of any one of claims 3 to 6, wherein the system further comprises one or more temperature sensors, each temperature sensor being configured to measure a temperature of the fluid at a respective location inside the fluid distribution system and provide those measurements to the temperature controller.
The system of any one of claims 3 to 7, wherein the temperature controller receives measurements of the temperature of the fluid at a plurality of locations within the fluid distribution system and is further configured to determine an amount of heat being exchanged with the fluid within different parts of the fluid distribution system.
The system of any one of claims 3 to 8, wherein the temperature controller is further configured to transmit a respective control signal to each of one or more further heat pump systems in response to determining that remedial action needs to be taken, the one or more further heat pump systems each affecting the temperature of the fluid within a respective portion of the fluid distribution system in proximity to that heat pump system through the transfer of heat between that heat pump system and the fluid distribution system, each of the further heat pump systems being fluidically isolated from the fluid distribution system, each control signal controlling or limiting the operation of the respective heat pump to which it is transmitted.
The system of claim 9, wherein the respective control signals sent to the one or more further heat pump systems controls the operation of those one or more further heat pump systems to at least partially counteract the effect of the heat pump system on the temperature of the fluid within the fluid distribution system.
The system of any one of the preceding claims, wherein the fluid distribution system is a water distribution system for delivering water from one or more water sources to one or more end users
The system of any one of the preceding claims, wherein the fluid distribution system delivers fluid to a plurality of end users.
The system of any one of the preceding claims, wherein the fluid distribution system delivers fluid over a large geographical area.
The system of any one of the preceding claims, wherein the heat pump system is configured to regulate the temperature within a data centre.
The system of any one of the preceding claims, wherein the heat pump system is a ground source heat pump system that is configured to transfer heat energy to or from a portion of the fluid distribution system indirectly by transferring heat energy with the ground in proximity to the portion of the fluid distribution system.