Apparatus for assessing the installation of a ground source heat exchanger and associated test methods

Abstract

A ground source heat transfer loop testing system is provided for checking the verticality of a heat transfer loop (2, figure 1) installed within a borehole (1) in the ground. The system includes an e

Description

The present invention relates to ground source heat exchangers and in particular equipment, systems and methods for use in testing the integrity of a ground source heat exchanger installations and in particular the heat transfer loop (HTL) component of the installation. Background of the Invention Fossil fuel burning boilers, which typically bum gas or oil, are commonly employed as the primary source of heated water for the central heating and heated water supply in many types of buildings, including domestic, commercial, industrial and agricultural structures. The move to replace fossil fuel boilers with ground source heat pumps (GSHP) as the primary source of heated water for these buildings is considered an important step towards reducing CO2 emissions over the coming years. GSHPs work by using thermal energy extracted from the ground to heat a building’s water. As such, an important component of any GSHP system is the ground source heat exchanger that extracts thermal energy from the ground and delivers it to the heat pump, which then transfers the thermal energy to central heating and hot water supply systems of a building. The ground source heat exchanger takes the form of one or more heat transfer loops (HTLs) that are buried within ground. Heat transfer loops come in two main forms, namely horizontal collectors and vertical collectors. Each type of collector comprises a pipework (typically made from polyethylene) of sufficient length to ensure that there is adequate contact area between the pipework and the surrounding ground formation to ensure that the heat pump can transfer sufficient energy to facilitate the generation of the required quantities of heated water. Horizontal collectors typically comprise pipework that is arranged across a relatively large area at a relatively shallow depth (about a metre or so) below the surface of the ground. In contrast, vertical collectors are deployed in boreholes that usually extend into the groundwater (e.g. typically by about 90-250 metres deep) and, as such, have a significantly reduced footprint. The reduced footprint enables a plurality of vertical heat transfer loops to be installed within a given area to achieve much greater contact area between the heat transfer loop pipework and the surrounding ground formation. Although heat transfer loops are most commonly employed to extract thermal energy from a ground formation, it is also possible to utilise them in reverse to provide cooling. In these operations heat is taken from the building structure, or application, and released into the ground. Regardless of whether the heat transfer loop is used to extract heat from a ground formation or deposit heat in the ground, the design of the ground source heat exchanger should ensure that the heat transfer is sustainable. It is known that, if the heat transfer loop pipework is incorrectly sized and / or wrongly installed, the amount of heat extracted from the ground by a collector can outstrip the ground formation’s ability to replenish the heat, which can cause the ground formation to freeze. Similarly, in the case of cooling applications, depositing too much in a given area can cause the ground formation to become too hot. In situations where several vertical heat transfer loops are employed, they are typically placed within a plurality of boreholes that are arranged in a grid like structure with suitable spacing between them to form a heat transfer loop matrix for use in the collection and / or dissipation of thermal energy. With regard to vertical collectors, the potential for failure coupled with the fact that a large proportion of the heat transfer loop is buried deep underground, and thus largely inaccessible, means that it is important to check the integrity of a heat transfer loop installation prior to use. To this end, the inventor of the present invention developed a test system and method for checking for leaks in the heat transfer loops following their installation in the ground, which is the subject of International PCT Application WO 2022 / 090687 A1. However, in the case of vertical collectors in particular, the need remains for further testing equipment and methods that can be used to check the integrity of a heat transfer loop installations before a Ground Source Heat Pump installation is fully commissioned, particularly in situations where multiple heat transfer loops are installed at the same time. Summary of the Invention With a view to carrying out further checks on a heat transfer loop once it has been installed within a borehole in the ground, the present invention provides a ground source heat transfer loop testing system according to claim 1. In particular the present invention provides a ground source heat transfer loop testing system for checking the orientation of a heat transfer loop installed within a borehole in the ground, said test system comprising: an elongated inclinometer, which is slidably receivable within a heat transfer loop, having a first sensor located adjacent to a first end of the inclinometer and a second sensor located adjacent to a second end of the inclinometer and wherein the sensors are configured to collect data regarding the angular orientation of the inclinometer; a delivery apparatus connected to the first end of the inclinometer so as to control the movement of the inclinometer within the heat transfer loop; and a data collection and interpretation unit configured to communicate with the inclinometer and collate the data collected as the inclinometer travels within the heat transfer loop and use said data to generate a visual representation of the actual path of the heat transfer loop within the borehole in the ground. It is known to employ inclinometers to assess the orientation of boreholes drilled for various purposes, with oil and gas reclamation being a particularly common field. However, the inclinometers employed in such operations tend to be relatively large and sophisticated due to the complex data that they are required to collect from a borehole. In contrast, the testing system of the present invention employs an inclinometer that is designed to be small enough to fit within, and travel along, the pipework of a heat transfer loop (HTL). Typically, heat transfer loops used as vertical collectors comprise a pair of identical polyethylene pipes that are joined together in parallel by way of a ll-bend joint. In use, the end of the heat transfer loop with the ll-bend joint is fed down the borehole first such that the free ends of the pipes extend out of the borehole at the surface ready to be connected to a heat pump via a connection manifold. The pipes that form these heat transfer loops are typically in the region of 40mm in diameter. Although the size of heat transfer loops can vary slightly, and may be smaller than 40mm, their size is generally limited by the relative surface area of the pipe compared to the pipe’s flow capacity. In contrast to the inclinometers employed in more sophisticated well logging equipment, which are necessarily larger, the sole purpose of the inclinometer employed in the test system of the present invention is simply to measure the orientation of one of the twin parallel pipes that form the heat transfer loop and in so doing the heat transfer loop as a whole. By assessing the orientation of the heat transfer loop it is then possible to determine its verticality (i.e., the position of the heat transfer loop relative to the normal). The elongated shape of the inclinometer and terminal spacing of the inclinometer’s sensors means that it follows the orientation of the heat transfer loop pipe faithfully as it makes its way through the pipe. In order to ensure that the inclinometer’s orientation follows that of the pipe, the inclinometer is shaped so as to be snugly but slidably received within the interior of one of the heat transfer loop’s twin pipes. It is envisaged, for example, that limiting the external diameter of the inclinometer to no more than 30mm would be appropriate when testing heat transfer loops formed from twin 40mm diameter pipes. Further, it is considered that providing the elongated body of the inclinometer at a length of between 300mm and 500mm is preferable. This length range strikes a balance between the provision of a suitable spacing between the end mounted sensors, which gives the inclinometer a suitable orientation sensitivity, and ensuring that the inclinometer is not too long to enable it to navigate any bends within the heat transfer loop that is installed within the ground. The test system of the present invention employs the inclinometer to measure the orientation of a heat transfer loop along its entire length from ground level, where the free ends of the twin pipes project above ground, to the U-bend, which is typically located at the bottom of the borehole. The test system uses the orientation data collected by the inclinometer to generate a visual representation of the actual path that the heat transfer loop takes within the borehole. The visual representation enables an assessment of the heat transfer loop’s verticality (i.e., the heat transfer loop orientation relative to the normal) to be carried out. Whilst the verticality of an individual heat transfer loop is a measure of the overall integrity of a ground source heat exchanger installation, this information is particularly important when multiple heat transfer loops are installed within a given area. Typically, in order to deploy multiples heat transfer loops at a particular site, multiple boreholes are required. The boreholes must be drilled with a suitable distance between them to ensure that the heat transfer loops do not compete for energy and reduce the efficiency of a heat transfer loop collection matrix or cause overheating of the ground formation by a heat transfer loop depositing matrix. Whilst multiple borehole systems are drilled with suitable separation at the surface, usually at least 6m centres, it is known that drilling operations do not always maintain borehole orientation (i.e., typically vertical). Strata which is particularly hard will cause the drill bit to deviate and take a path of least resistance, which can affect a borehole’s orientation. Information about the actual position of the heat transfer loop within the borehole is required to ensure that the heat transfer loops have adequate spatial distribution to ensure heat transfer efficiency in accordance with the design requirements. In addition to energy transfer efficiency it is also necessary to confirm that boreholes that are drilled do not damage existing boreholes that have been drilled previously. This can result in result in leaks from the heat transfer loops which will render the energy exchange matrix useless and cause potentially damaging chemicals to be released into the environment. In order to collect orientation data from along the length of a heat transfer loop, the inclinometer travels within the interior of the heat transfer loop pipe. The role of the delivery apparatus, which is connected to one end of the inclinometer, is to control the passage of the inclinometer through the heat transfer loop. Whilst it is envisaged that the delivery apparatus could be used to push and pull the inclinometer through the heat transfer loop (i.e., using sections of rigid pipework), it is considered preferable that the inclinometer is configured to travel from ground level down to the ll-bend of the heat transfer loop under the force of gravity. To this end, the inclinometer may be suitably weighted so that it travels down the borehole due to gravity. It is envisaged that when most heat transfer loops are installed, they typically contain a quantity of liquid. The liquid helps counteract the external pressures imparted on the heat transfer loop during the installation process and, in so doing, maintains the structure of the heat transfer loop by counteracting groundwater pressure. In these situations, the inclinometer may preferably be sufficiently weighted so as to sink within a fluid filled heat transfer loop. Further preferably, the second end of the inclinometer may be provided with an anchor point, to which a detachable weight can be attached so as to ensure the inclinometer sinks within a fluid filled heat transfer loop. Preferably the delivery apparatus may comprise a cable mounted on a spool that is operable to support the inclinometer within the heat transfer loop. By supporting the inclinometer, the delivery apparatus controls the transport of the inclinometer through the heat transfer loop. In addition, the delivery apparatus preferably further comprises a controller that is configured to: a) determine the rate at which the inclinometer is transported within the heat transfer loop; and / or b) determine the distance travelled within the heat transfer loop by the inclinometer. In this was the test system can be used to assess both the orientation (i.e. verticality) of a heat transfer loop and its length, which helps to confirm the depth of the heat transfer loop installation. Further, it is preferable that the data collection and interpretation unit is operably connected to the controller of the delivery apparatus. In this way the orientation data collected from the inclinometer sensors can be combined with the depth data to provide a scaled visual representation of the heat transfer loop. It is envisaged that the scaled visual representation may preferably be provided in a three dimensional representation. Also, the data collection and interpretation unit may preferably be provided on board the delivery apparatus. In this way the delivery apparatus provides an integrated piece of test equipment for use in assessing the orientation of heat transfer loops. Preferably, the inclinometer and the data collection and interpretation unit may be configured to communicate wirelessly. Alternatively, the inclinometer may further comprise an electrical connection point configured to receive a data transmission cable for wired communication with the data collection and interpretation unit. Preferably, the data collection and interpretation unit may be configured to collect GPS data about the heat transfer loop and associate such with the visual representation. In this way each visual representation provided for a particular heat transfer loop can be easily accessed at a later date. The data collection and interpretation unit will record and pinpoint the actual position of the heat transfer loop being tested by using GPS. In addition to the test system, the present invention also provides a method of checking the orientation of a ground source heat pump heat transfer loop in accordance with claim 10. Although not its only aim, the main purpose of checking the orientation of the heat transfer loop is to assess its verticality (i.e., its orientation relative to the normal). In particular there is provided a method of checking the verticality of a ground source heat pump heat transfer loop installed within a borehole in the ground prior to the commissioning of the ground source heat pump, said method comprising: deploying an elongated inclinometer, with sensors located adjacent to either end thereof, within a heat transfer loop and using delivery means to control the movement of the inclinometer within the heat transfer loop; using the sensors to collect data about the angular orientation of the inclinometer as the inclinometer travels between a start point in the heat transfer loop and an end point in the heat transfer loop; processing the data collected by the sensors to generate a visual representation of the actual path of the heat transfer loop within the borehole in the ground and using such to check the verticality of the heat transfer loop. Preferably the heat transfer loop comprises a pair of parallel pipes connected together at one end thereof by a ll-bend joint; and whereby the start point of the heat transfer loop is located adjacent to the U-bend and the end point of the heat transfer loop is located adjacent to the surface of the ground. In this way the orientation data for the heat transfer loop is collected as the inclinometer is retrieved from the lowermost point of the heat transfer loop by the delivery means, thereby enabling the rate at which the inclinometer travels through the heat transfer loop to be measured. In addition, preferably the method may include collecting GPS data about the heat transfer loop and associating it with visual representation. Once again, it is envisaged that collecting GPS data for each heat transfer loop on testing, and then associating it with the visual representation of the heat transfer loop, makes it much easier to track the information and access it again at a later date. According to a further aspect of the present invention there is provided a method of assessing the installation of a ground source heat pump heat transfer loop matrix prior to the commissioning of the ground source heat pump, said method being in accordance with claim 13. In this regard, a plurality of heat transfer loops in a heat transfer loop matrix are tested and the data collected from each heat transfer loop is used to produce visual representations for all of the heat transfer loops that are combined to provide a map of the transfer loop matrix. Further preferably the visual representations are provided as three dimensional virtual models. Preferably, the GPS data collected for each heat transfer loop may be used to arrange the heat transfer loops in accordance with their relative positions in the matrix. It is envisaged that by testing each of the heat transfer loops in a heat transfer loop matrix in turn, the method of the present invention can be used to map out the entire matrix and, in so doing, enable the integrity and efficiency of whole installation to be assessed before commissioning. In situations where the map indicates potential conflicts, remedial action can be taken before commissioning of the system is carried out. This allows for considerable savings on both time and cost. For example, in cases where the orientation of two adjacent heat transfer loops is such that their combined use would draw too much thermal energy from the ground, the operation of the clashing heat transfer loops can be modified by altering the flow of fluid within the heat transfer loop to ensure that the ground formation is not overworked or overloaded. Also, in situations with extreme conflicts, steps can be taken to write off and decommission the heat transfer loop to avoid any issues. As the testing of the present invention is conducted prior to commissioning whilst the drilling equipment is still on site, there option of installing additional heat transfer loops in new boreholes remains. Brief Description of the Drawings The present invention will now be described with reference to the drawings, wherein: Figure 1 shows a diagrammatic view of the test system of the present invention deployed within a heat transfer loop installed within a borehole; Figure 2 shows the inclinometer of the test system within a vertical section of heat transfer loop; Figure 3 shows the inclinometer of the test system within a section of heat transfer loop that is offset from vertical; Figure 4 shows an example of the visual representation produced using the orientation data collected by test system of the present invention; and Figure 5 shows a map for a heat transfer loop matrix formed from the visual representations produced from the heat transfer loops in the matrix. Detailed Description of a Preferred Embodiment The main focus of the method and apparatus of the present invention is to test key characteristics of a heat transfer loop following its installation within a borehole that has been drilled into the ground and to confirm its actual position. Although the testing system and method of the present invention are primarily concerned with assessing the heat transfer loops of heating applications, where energy is taken from the ground for utilisation by a heat pump, the skilled person will appreciate that heat transfer loops employed for cooling applications (i.e., heat pumps that take energy from a building and transfer it to the ground) can also be assessed using the present invention. It will be appreciated that, whilst in most installations the intention of the drill operators when forming a borehole for a ground source heat transfer loop is to maintain the verticality of the borehole, this is not always possible. For example, strata that is particularly hard can cause the drill bit to deviate and take a path of least resistance, which may not be truly vertical. In the light of this variance in the orientation of a borehole from one drilling operation to the next tools have been developed to monitor the orientation of a borehole along with other characteristics of the borehole. However, the inventor has discovered that, whilst the orientation of the borehole an important consideration during the installation of a ground source heat exchanger, the orientation of the heat transfer loop itself, inside the borehole, is a more important consideration when assessing whether the fully commissioned Ground Source Heat Pump will function effectively. Given the smaller internal diameter of the pipes typically employed in the heat transfer loops used in vertical ground source heat exchangers (e.g., about 32mm), the inventor has found that the well logging tools currently used to assess boreholes are unsuitable for the task and in most cases over sophisticated. The test system of the present invention is therefore focused not on assessing the characteristics of a borehole but rather the heat transfer loop of a vertical ground source heat exchanger once the loop has been installed in the borehole. Turning now to Figure 1, a borehole 1 with a heat transfer loop 2 installed therein is shown. The heat transfer loop 2 comprises a pair of parallel pipes 3, 4 joined together at their leading (i.e., downhole) ends by a U-bend joint 5. As the construction of heat transfer loops 2 is well known to the skilled person, further details about the specifics of heat transfer loops 2 will not be provided here unless such is necessary to explain the operation of the present invention. Although not shown in Figure 1, it will be appreciated that the heat transfer loop 2 is installed downhole filled with a fluid 6 in order to maintain the structural integrity of the pipes 3, 4 under the external pressure experienced by the heat transfer loop 2 from the grout (not shown) or groundwater within the borehole. It is envisaged that the test system of the present invention with generally be employed once the heat transfer loop 2 has been deployed within the borehole 1 and secured in place; usually with grout (not shown) that assisting in transferring thermal energy to the loop 2. In some installations, where the heat transfer loop extends into groundwater, the design of the system may not require the installation of grout as the groundwater itself will provide sufficient heat transfer efficiency with the surrounding ground. The test system of the present invention comprises an inclinometer 7 that is delivered downhole within the interior of a pipe 3 of the installed heat transfer loop 2. The inclinometer is connected to the delivery apparatus 8 via a cable 9, which is preferably wound and unwound around a winch that is automatically operated by the delivery apparatus 8. It is envisaged that alternative approaches for delivering the inclinometer through the heat transfer loop pipe 3 can be adopted without departing from the scope of the present invention provided they facilitate both deployment downhole and retrieval up-hole of the inclinometer. While the manual deployment and retrieval of the inclinometer is possible using some embodiments of the present invention, it is considered beneficial that the delivery apparatus is automated as this will guarantee that the rate at which the inclinometer travels through the heat transfer loop pipe 3 is controlled and monitored. To this end the delivery 8 apparatus is preferably provided with a data collection and interpretation unit in the form of processing unit 8a. It is envisaged that the processing unit 8a may be provided in the form of an on-board computer, that is also capable of controlling the winch to unwind and wind the cable 9 in order to deploy and retrieve the inclinometer 7. Although not shown, it is envisaged that in preferred embodiments of the present invention, the data processing unit 8a will also be capable of confirming and recording its exact position using GPS. This will confirm the above ground spatial separation of a plurality of heat transfer loops. By operating the processing unit 8a to control the movement of the inclinometer 7 within the heat transfer loop 2, and in particular the extent to which the cable is unwound before the inclinometer reaches the U-bend 5 of the heat transfer loop 2, data about the depth of the heat transfer loop 2 can also be collected when checking its orientation (i.e., verticality). In this way the test system of the present invention collects important data about a given heat transfer loop installation so that the installation can be signed off, if found to be acceptable, before it is connected to the rest of the ground heat source pump system (not shown) and fully commissioned for use. Similarly, if there are issues that could affect the efficiency of the heat transfer matrix due to depth or verticality on one or more boreholes these can be addressed prior to commissioning. The remedial options are to adjust the flow rate, write off the heat transfer loop or install heat loops in additional boreholes. The inclinometer 7 of the preferred embodiment will now be described in more detail with reference to Figures 2 and 3. Figure 2 shows the inclinometer 7 in situ within a heat transfer loop pipe 3 of a heat transfer loop 2 that has been installed within a borehole. For the sake of clarity, the rest of the heat transfer loop 2 and the borehole 1 are not shown. Similarly, Figure 3 shows the inclinometer 7 in situ within a heat transfer loop pipe 3 of an installed heat transfer loop 2. However, in Figure 3 the orientation of the heat transfer loop pipe 3a is offset from vertical. The inclinometer 7 comprises a water-tight elongated body 10 within which a pair of sensors 11, 12 are housed in a spaced apart arrangement. It is envisaged that the elongated body 10 is between 300mm to 500mm long. This range of sizes aims to strike a balance between adequate inter sensor spacing whilst ensuring the inclinometer’s length does not affect its ability to orientate itself relative to the heat transfer loop. The first sensor 11 is provided at the up-hole (i.e., trailing) end of the elongated body 10 and the second sensor 12 is provided at the downhole (i.e., leading) end of the elongated body 10. The sensors 11, 12 collect data about their orientation relative to the normal (i.e., vertical). This orientation data is then communicated back to the processing unit 8a located in the delivery apparatus 8. It is envisaged that the orientation data could be transferred wirelessly or along the wired connection, which may preferably be combined with the cable 9 that is used to connect the inclinometer to the delivery apparatus 8. It is envisaged that any pair of sensors 11, 12 that are capable of monitoring their position relative to one another can be suitably employed in the inclinometer of the present invention, provided they are of a suitable size to be accommodated within the elongated body 10 of the inclinometer. In the preferred embodiment shown the orientation data collected by the sensors 11, 12 is communicated back to the data collection and interpretation unit provided by the processing unit 8a via the cable 9, which is attached to the inclinometer 7 via an electrical connection point 13 provided at the up-hole (i.e., trailing) end of the inclinometer 7. Although the data collection and interpretation unit is shown as preferably being onboard the delivery apparatus 8 as part of the processing unit 8a, it is appreciated that the data collection and interpretation unit may be provided separately from the delivery apparatus in the form of a laptop or hand held device. In such embodiments, the data collection and interpretation unit may communicate with the inclinometer 7 and its sensors 11,12 using wireless technology. Similarly, the data collection and interpretation unit may communicate with the delivery apparatus wirelessly. In embodiments where the data collection and interpretation unit is a stand-alone device, the delivery apparatus may no longer require processing unit and can instead simply be provided with controller means that operate the winch to wind and unwind the cable 9 and the attached inclinometer 7. Once installed within a borehole, heat transfer loops typically contain a liquid. The liquid may be either water or thermal transfer fluid (TTF), which is the chemical used in the system when it is operational. The TTF acts as an antifreeze. In order to facilitate the deployment of the inclinometer 7 down the liquid containing heat transfer loop pipe 3, the inclinometer 7 is preferably weighted so that it sinks within the liquid. Whilst the inclinometer 7 itself may itself be heavy enough to sink at the desired rate, it is envisaged that the inclinometer 7 may preferably be provided with weight retaining means 14 at its leading end. The weight retaining means 14, which may simply take the form of a loop, are configured to enable a suitable weight 15 to be suspended from the inclinometer 7. It is appreciated that configuring the shape of the inclinometer 7 to be snuggly received within the heat transfer pipe helps to ensure that the inclinometer adopts the same general orientation as the heat transfer loop pipe within which it is travelling. By way of example, in order to make the inclinometer snuggly receivable in the most common size of heat transfer loops, which have an internal diameter of about 32mm, the elongated body of the inclinometer preferably has an external diameter of about 28mm. Of course, the external diameter of the inclinometer may vary depending on the size of the heat transfer loop pipe that is to be assessed. However, it is envisaged that suspending the weight from the leading end of the inclinometer is considered more preferable that simply increasing the weight of the inclinometer itself because the hanging weight 15 helps to ensure that the inclinometer 7 adopts the same orientation as the heat transfer loop 3a when its orientation is offset from vertical; as in Figure 3. The test system of the present invention is employed in a method of checking the orientation (and more preferably the verticality) of a ground source heat pump heat transfer loop installed within a borehole in the ground prior to the commissioning of the ground source heat pump. A preferred embodiment of this method will now be described with reference to the Figures. Following the formation of a borehole 1 using a suitable drilling operation, a heat transfer loop 2 is inserted in the borehole. Once the full length of the heat transfer loop 2 has been delivered into the borehole, grout can be added to support the heat transfer loop. The grout also helps to facilitate the transfer of heat between the heat transfer loop and the surrounding ground formation. It is envisaged that in some applications, such as when the borehole is directed into groundwater, grout will be excluded from the design as the groundwater is considered to provide adequate thermal transfer efficiency and the grout is not required. Once this initial installation stage is complete, the site is ready for the application of the method of the present invention. The delivery apparatus 8 is positioned adjacent to the top of the borehole with the inclinometer 7 connected to it via cable 9. The inclinometer 7 is then inserted into an open end of one of the pipes 3 that make up the heat transfer loop 2 held within the borehole 1. The delivery apparatus 8 is then operated to deploy the inclinometer 7 down the borehole within the interior of the liquid containing heat transfer loop pipe 3. As the cable 9 is unwound gravity acts to sink the inclinometer within the liquid 6, as is shown in Figure 1. Preferably a weight 15 is attached to the leading end of the inclinometer 7 to aid in the downward decent of the inclinometer within the heat transfer loop pipe 3. Although it is envisaged that the data may be collected from the inclinometer’s sensors 11, 12 by the data collection and interpretation unit as the inclinometer travels downhole within the heat transfer loop pipe 3 to the base of the heat transfer loop at the ll-bend joint 5, it is considered preferable that the orientation data from the sensors is not collected until the inclinometer begins its return journey from the bottom of the heat transfer loop. This approach is considered preferable because the rate at which the inclinometer 7 is retrieved can be accurately controlled by the delivery apparatus 8 and the on board processing unit 8a. This in turn allows the orientation data collected by the sensors 11, 12 to be accurately mapped along the entire length of the heat transfer loop pipe 3 at predetermined points (e.g., every 1,2 or 5 metres). Preferably the method also includes collecting data on the extent to which the inclinometer travels within the heat transfer loop pipe 3 before it reaches the U-bend joint 5. In this way the method can assess both the depth (i.e., length) of the heat transfer loop and its orientation (i.e., verticality). Using the data collected by the inclinometer sensors 11, 12, the data collection and interpretation unit (either as part of the processing unit 8a or a standalone device) produces a graphical representation of the deviation of the heat transfer loop 3 along its entire length. The graphical representation is generated using the data collected from the individual heat transfer loop pipe 3, and the fact that the heat transfer loop pipes 3, 4 are essentially parallel to the graphical representation 20. A preferred example of the graphical representation 20 is takes a ‘dartboard configuration’ and is shown in Figure 4. The dartboard configuration comprises a circular scale with a graduated cross hair that has graduations arranged in both the X axis 21 and the Y axis 22. In the preferred embodiment the centre point of the crosshair represents the normal (i.e., absolute vertical), which the graduations represent the extent of deviation from the normal. Each graduation preferably denotes a 1 metre distance from the last mark on the crosshair; however it is envisaged that different scales may be employed without departing from the general concept of the present invention. As can be appreciated from the example of the dartboard graphical representation shown in Figure 4, the pathway 23 of the heat transfer loop pipe 3 (and by inference the entire heat transfer loop 2) is mapped along its entire length from a bottom point (marked by a triangle), which is preferably at the ll-bend 5, to the top point (marked by a diamond), which is preferably where the pipe 3 reaches ground level at the borehole opening. It will be appreciated that the top points (as represented by a diamond in Figure 4) will be where the original position of the loop was intended to be at the surface at the design spacing. Essentially, in preferred embodiments the mapping of the heat transfer loop is done by moving the inclinometer from the lowest portion of the pipe (i.e., the bottom point) to the highest portion of the pipe (i.e., the top point) and collecting orientation data along the way. By collecting the orientation data as the inclinometer 7 is retrieved from the bottom of the pipe 3 by the delivery apparatus 8, it is possible to enhance the pathway 23 with additional mid points (marked with a cross) at predetermined points along the length of the pipe 3. It is envisaged that the graphical representation is preferably provided as a three-dimensional virtual model which can be manipulated to provide different viewpoints of the heat transfer loop installation. It is envisaged that, while the dartboard graphical representation 20 provides useful information regarding the installation characteristics of a given heat transfer loop 2, the information is even more beneficial when assessing a ground source heat exchanger matrix that comprises multiple vertical heat transfer loops 2 installed adjacent to one another in neighbouring boreholes 1. In accordance with a further aspect of the present invention there is provided a method of assessing the spatial distribution of a plurality of ground source heat pump heat transfer loops installed within neighbouring boreholes in the ground to form a ground source heater exchanger matrix. This method uses the ability to collect the orientation data for a target heat transfer loop across an entire area of associated heat transfer loops to provide a map of the ground source heater exchanger matrix which can be used to assess potential oversaturation of a particular downhole region. This ability to assess the respective orientations of the heat transfer loops in a given matrix is crucial because, whilst multiple borehole systems are drilled with suitable separation at the surface (usually at least 6m between the centre of neighbouring boreholes), as already noted drilling operations do not always maintain borehole vertical ity. The actual position of a heat transfer loop within its borehole is required to ensure that the heat transfer loops have adequate spatial distribution to ensure heat transfer efficiency in accordance with the design requirements. In addition to energy transfer efficiency it is also necessary to confirm that boreholes that are drilled do not damage existing boreholes that have been drilled and tested previously. This can result in result in leaks from the heat transfer loops which will render the ground source heat exchanger matrix useless and cause potentially damaging chemicals to be released into the environment. Figure 5 shows an example of a ground source heater exchanger matrix 24 that is produced using a plurality of dartboard graphical representations 20a, 20b, 20c for neighbouring heat transfer loops. Once again, it is envisaged that the entire heat exchanger matrix can also be represented as a three-dimensional virtual model for use in confirmation of the actual position of the matrix within the underlying geological strata, and also for record keeping.

Claims

25Claims1. A ground source heat transfer loop testing system for checking the verticality of a heat transfer loop installed within a borehole in the ground, said test system comprising:5 an elongated inclinometer, which has an external diameter of no more than30mm so that it is slidably receivable within a heat transfer loop, having a first sensor located adjacent to a first end of the inclinometer and a second sensor located adjacent to a second end of the inclinometer and wherein the sensors are configured to collect data regarding the angular orientation of the inclinometer;10 delivery apparatus connected to the first end of the inclinometer so as tocontrol the movement of the inclinometer within the heat transfer loop; anda data collection and interpretation unit configured to communicate with the inclinometer and collate the data collected as the inclinometer travels within the heat transfer loop and use said data to generate a visual representation of the actual path 15 of the heat transfer loop within the borehole in the ground.

2. The testing system of claim 1, wherein the inclinometer is sufficiently weighted so that, in use, the inclinometer sinks within a fluid filled heat transfer loop, whereby the fluid is water or a thermal transfer fluid (TTF).

3. The testing system of claim 1, wherein the second end of the inclinometer is 20 provided with an anchor point, to which a detachable weight can be attached so as to ensure that, in use, the inclinometer sinks within a fluid filled heat transfer loop.

4. The testing system of any one of claims 1 to 3, wherein the delivery apparatus comprise a cable mounted on a spool that is operable to transport the inclinometer within the heat transfer loop.25 5. The testing system of claim 4, wherein the delivery apparatus furthercomprises a controller that is configured to:a) determine the rate at which the inclinometer is transported within the heat transfer loop; and / orb) determine the distance travelled within the heat transfer loop by the30 inclinometer.27 06 256. The testing system of claim 5, wherein the data collection and interpretation unit is operably connected to the controller.

7. The testing system of any one of claims 1 to 6, wherein the inclinometer andthe data collection and interpretation unit are configured to communicate wirelessly.5 8. The testing system of any one of claims 1 to 6, wherein the inclinometerfurther comprises an electrical connection point configured to receive a data transmission cable for wired communication with the data collection and interpretation unit.

9. The testing system of any one of claims 1 to 8, wherein the data collection 10 and interpretation unit is configured to collect GPS data about the heat transfer loop and associate such with the visual representation.

10. A method of checking the orientation of a ground source heat pump heat transfer loop installed within a borehole in the ground prior to the commissioning of the ground source heat pump, said method comprising:15 inserted an elongated inclinometer, with sensors located adjacent to eitherend thereof, into a heat transfer loop and using delivery means to control the movement of the inclinometer within the heat transfer loop;using the sensors to collect data about the angular orientation of the inclinometer as the inclinometer travels between a start point in the heat transfer20 loop and an end point in the heat transfer loop; andprocessing the data collected by the sensors to generate a visual representation of the actual path of the heat transfer loop within the borehole in the ground and using such to check the orientation of the heat transfer loop.

11. The method of claim 10, wherein heat transfer loop comprises a pair of25 parallel pipes connected together at one end thereof by a U-bend joint; andwhereby the start point of the heat transfer loop is located adjacent to the U-bend and the end point of the heat transfer loop is located adjacent to the surface of the ground.

12. The method of claim 10 or 11, further comprising the step of collecting GPS 30 data about the heat transfer loop and associating it with visual representation.

13. A method of assessing the installation of a ground source heat pump heat transfer loop matrix prior to the commissioning of the ground source heat pump, said method comprising:a) using the method of claim 10, 11 or 12 to check the orientation of each 5 heat transfer loop within the matrix and produce a visual representation of said loop;b) combining the visual representations collected in step a) and arranging the heat transfer loops according to their relative positions within the matrix in order to provide a map of the transfer loop matrix; andc) assessing the map to identify potential conflicts between the heat 10 transfer loops within the matrix.

14. The method of claim 13, wherein the GPS data collected for each heat transfer loop is used to arrange the heat transfer loops in accordance with their relative positions in the matrix.27 06 25Application No: GB2413823.2Examiner: Mr Henry NevellClaims searched: 1-14Date of search: 11 November 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X Y X,Y X,Y Y A A A X; 1-9,Y: 10-14 X: 1-9,Y 10-14 X; 1-9, Y: 10-14 Y:10-14 US5172480 A (LABUC) See figure 1 numerals 20, 22, 26, 30 and description thereof, e.g. column 3 lines 22-38 US2016 / 237806 Al (LANGE) See figures 1-4B and paragraphs 20, 25 and 30 US2016 / 076359 Al (DANISCH) See figures 3, 7, 8 and paragraph 110 CN205374768 U (CHINA ACAD BUILDING RES) See 'detailed description of invention' discussing use of inclinometer within a U-type heat pump exchanger US2016 / 333682 Al (GRIFFING) See paragraph 51 (display feature) US2006 / 075645 Al (SEIGEL) See paragraph 13 (mapping feature) CN102134989B (CHONGQING HU AYU ELECTRIC) See towards end of preamble section (mapping / display feature)Categories: X Document indicating lack of novelty or inventive step A Document indicating technological background and / or state of the art. Y Document indicating lack of inventive step if combined with one or more other documents of same category. p Document published on or after the declared priority date but before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:Search of GB. EP, WO &US patent documents classified in the following areas of the UKCX :Worldwide search of patent documents classified in the following areas of the IPC E21B; F24D; F24H; F24T; G01B; G01MThe following online and other databases have been used in the preparation of this search reportSEARCH-PATENTInternational Classification:Subclass Subgroup Valid From GO IM 0099 / 00 01 / 01 / 2011 E21B 0047 / 02 01 / 01 / 2006 E21B 0047 / 024 01 / 01 / 2006

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