DIRECT INSERTION GROUND LOOP HEAT EXCHANGER
A direct insertion ground loop heat exchanger, comprising an at least partially hollow pointed driving tip having at least one orifice therethrough for dispersing water through the driving tip to ease insertion into the ground, such that placing the driving tip onto the ground and urging water through the orifices will separate and part the ground easily, permitting the insertion of the driving tip deeper and deeper into the ground in combination with a hollow outer tube having an inner diameter attached to the driving tip, said tube extending upwardly from out of the driving tip and terminating above the ground for accessibility. Therefore, by urging water through the direct insertion ground loop heat exchanger, water sprays out from orifices in the driving tip, making insertion into the ground quite simple and easy.
1. Field of the Invention
The present invention relates to a ground loop heat exchanger, methods of manufacturing same, methods of using same, equipment to insert a ground loop heat exchanger into the ground and methods of doing business. More particularly, the invention relates to a direct insertion ground loop heat exchanger, and methods of making and using same and equipment to insert the ground loop heat exchanger into the ground, methods of making and using same.
2. Description of the Prior Art
Renewable energy is being heavily utilized and investigated in order to reduce our nation's contribution to greenhouse gases, as well as reducing our dependence on foreign oil. Heating homes and businesses is one of the largest energy costs realized by consumers. The search has been on for consistent, environmentally friendly and inexpensive methods of heating our homes and businesses. Solar energy, wind power and geothermal powers are all being investigated as a means of renewable energy. Currently, each of these methods have their own individual issues with cost, return on investment, environmental concerns, among other issues.
Of these methods, the green friendly method of geothermal heating and cooling is especially favorable because it meets many of the criteria, although traditionally it has been relatively expensive and labor intensive to install the requisite heat exchangers in the ground. Above all, it is well known that the earth can be used as a consistent source of heat or cool because it is consistent in temperature the deeper you go. After insertion of a ground loop heat exchanger into the earth, the temperature fluctuation becomes less and less as you go deeper. In fact, just 10 to 20 feet into the earth yields some fairly consistent temperatures, regardless of geography.
Geothermal engineers have been using this concept to power their geothermal heat pumps to deliver heating and cooling to their customers for many years. Geothermal, or ground source heat pumps, have proven themselves to be a more efficient heating and air conditioning source than other heat pumps. Conventional geothermal installations for heating and cooling of homes and businesses are well known in the art, and they have used either horizontally installed ground loops placed into ground excavation sites or deep trenches. Needless to say, such an installation requires removal of a great deal of surface soils and topography. In some cases of retro-fitting a ground source heat exchanger, pavement, driveways, trees, and other landscaping needed to be removed. The number of man hours and equipment and the attendant monetary costs in order to dig up all this terrain is enormous, and has been a barrier to its widespread use among the public.
It has become abundantly clear that there is a need for a more environmentally friendly, less expensive and efficient method for installing the heat exchangers necessary to operate a ground source heat pump. In an attempt to overcome the abovementioned obstacles, contractors have attempted to utilize vertically installed heat exchangers instead of the horizontally installed heat exchangers. However, installing these vertical heat exchangers, including the most common types of vertical ground loop heat exchangers, requires tremendous effort to properly bore a hole to then install the heat exchanger into the ground.
Typically a vibrating or rotating vertical boring machine needs to be used, and they become problems for the environment, ground source water contamination that is common among such vertical loop installations, and if any pockets of cavernous space need to become penetrated, the county inspectors would require a grout or cement back filling in order to stabilize and seal the borehole. The earth is full of underground water sources, and those water sources cannot be contaminated by drilling and excavation with a vertical boring machine. Such machines are so large that they create many problems for landscaping and noise prevention and water runoff, not to mention the vibration of the machinery itself cracking foundations and basement walls when drilling near other buildings. In highly populated areas, such an installation can wreak havoc with all of the neighbors, as well as the streets and driveways. Consequently, while a vertical heat loop installation may help reduce land area requirements, the traditional method that is used is not only troublesome for excavation reasons, but is much more expensive than an installer would like to have it be. This traditionally used specialized drilling equipment is not a piece of equipment that normal heating and cooling professionals would own because it costs tens of thousands to hundreds of thousands of dollars to purchase. Inevitably, the vertical installation may need to occur during a rainy period, and in order to prevent cave-ins, further precautions must be taken, which will not be addressed herein, because the present invention will alleviate this situation.
Therefore, there has been a long felt need in the industry for a convenient, inexpensive, environmentally friendly, and particularly effective method of installing vertical or angled heat exchangers or in ground installations that are not susceptible to environmental concerns like rain, cave-ins and ground water contamination. It is further desired to reduce this cost as much as possible, in order to provide more wide spread availability of ground loop heat exchanger installations.
SUMMARY OF THE INVENTIONIn accordance with the above-noted desires of the industry, the present invention provides various aspects, including a direct insertion ground loop heat exchanger, an in ground installation means, a method of making, using and selling the same, and various methods of installing it and methods of doing business as well.
The present invention discloses a first aspect of a direct insertion ground loop heat exchanger having a novel drilling tip for easing insertion of the heat exchanger directly into the ground, without disturbing the surrounding earth, landscaping or buildings. Insertion is accomplished through many different aspects, including hand insertion, mechanical insertion, oscillating roller hammer insertion, hydraulic direct insertion, or any other suitable means of inserting into the ground. The direct insertion is achieved easily with the use of my novel device for inserting an HDPE (or other suitable) pipe that is designed as a ground loop heat exchanger into the ground. My specially designed steel (or other suitable material) driving tip having perforations bored therethrough is affixed to the direct insertion ground loop heat exchanger. By using oscillating downward and upward force, my specialized driving tip penetrates the soil and moves objects aside while water jets extending through the entire tip is ejected through the tip to loosen the soil ahead of the tip and lubricate the process allowing for a rapid insertion.
Especially useful is my concentric tube design wherein, in one aspect, one tube is inserted through the middle of another tube such that the tube utilized to direct water to loosen the soil and emit through the tip is afterward used as the outer wall of the annular flow cavity for heat exchanger fluid. In another aspect, the water flow tube is coextruded in a multilumen profile along with the downflow and upflow heat exchanger fluid concentric flow channels wherein the water flow utilized to loosen and lubricate the soil is used for this purpose only and is not used for heat exchanger fluid flow. The concentric tube design of both aspects provides the ability to insert a single insertion unit into the ground, while allowing for bi-directional flow.
This single insertion unit allows for the heat exchanger to exhibit two functions at the same time, i.e. it can be inserted into the ground and then also provide for heat exchanger fluid flow using the same assembly. Furthermore, additional benefits include having the ability to have laminar flow in the downflow pipe while turbulent flow in the up flow under an equal volumetric flow rate. This increases heat transfer in the ground coupled outer tube without increasing pump energy in the laminar flow inner pipe. In addition, this provides an easily insulated inner flow tube to help maintain temperatures for improved thermal efficiency once the installation is complete.
Although the invention will be described by way of examples herein below for specific aspects having certain features, it must also be realized that minor modifications that do not require undo experimentation on the part of the practitioner are also covered within the scope and breadth of this invention. Additional advantages and other novel features of the present invention will be set forth in the description that follows and in particular will be apparent to those skilled in the art upon examination or may be learned within the practice of the invention. Therefore, the invention is capable of many other different aspects and its details are capable of modifications of various aspects which will be helpful to those of ordinary skill in the art, all without departing from the spirit of the present invention. Accordingly, the rest of the description will be regarded as illustrative rather than restrictive.
In accordance with various aspects of the present invention, there is shown a novel insertion driving tip to be secured onto the end of a concentric tube heat exchanger assembly, a novel fluid flow construction, various novel equipment aspects and methods of driving the heat exchanger assembly into the ground to alleviate any environmental disruption, and numerous other considerations pertinent to the present invention. Specific aspects will be discussed, although there are many ways to utilize the present invention. Certain examples will be more fully described herein below. Any suitable method of driving the insertion tip and heat exchanger assembly into the ground down to the desired heated earth area is feasible and desirable, depending upon the soil conditions and equipment availability. Whether insertion is completed through hand driving, machine driving, hydraulic driving, oscillating hammer driving or jackhammer driving, will depend upon the individual circumstances of the job itself. With that in mind, we now investigate the various aspects of the invention that I have envisioned for success.
Referring now to the drawings in detail, FIG.1 is an environmental view of an operator utilizing a hydraulic insertion method for driving an insertion tip with a heat exchanger assembly appended thereto into the ground. The entire assembly is generally indicated by the numeral 10, which also includes an insertion tip 12 attached to a direct insertion ground loop heat exchanger 14 being driven into the ground by a hydraulic means using a high pressure hose 16 supported by a pipe magazine 18. A hose spool 20 feeds the hose by the power and control unit 22. Pump 24 pumps water from the water reservoir 30 as the motor or battery 28 drives the mechanism. Water reservoir 30 feeds pump 24. A pipe driving pressure transducer 32 senses the resistance of the heat exchanger being inserted into the ground and when it reaches a preset level, reverses the hydraulics to raise the heat exchanger a short distance and then the hydraulics again reverses to continue the downward insertion. This process is repeated and results in an up and down motion on the heat exchanger with the downward stroke distance being the dominant overall motion causing the heat exchanger to be inserted into the earth, driving the insertion tip deeper into the ground, seeking the stable temperature below the surface. Such a hydraulic driving of the direct insertion ground loop heat exchanger into the ground is but one method of insertion into the ground. This method is also very effective at extracting the heat exchanger assembly if necessary, without the need for digging up the dirt around it.
Still looking at
Experimentation has shown that to use the direct insertion ground loop heat exchanger of the present invention, it is best to drive the direct insertion ground loop heat exchanger into the ground to a depth of from about 6 meters to 15 meters to find the proper thermal zone to operate a standard heat pump. Further, we have found that it is advantageous to provide between about five to seven, and preferably six, heat exchanger insertions per ton of heat pump capacity depending upon the circumstances and the amount of thermal energy needed for the job.
Looking next to
After the heat exchanger is inserted into the ground and the heat exchanger system is connected to a heat pump or a heat exchanger for a heat pump, heat exchanger fluid 52 is pumped through the inner tube 48 and escapes through perforations therein to the outer tube 46 and then back up to the surface for use in the heat pump. Heat exchanger fluid 52 enters into the cavity created by the outer tube via perforations in the inner tube 48, to be shown in more detail with relation to
It should be noted that there are many variations on the internal configurations for my concentric tube design. The concentric tube system may be a one piece extruded piece, or it may be a multiple piece construction. For the multiple piece construction, it can be a two piece design with separate elements of an outer tube sleeved over an inner tube, or it may even be a three piece design (See
Looking next to
Preferably, the driving tip 42 is made of a steel or steel tipped aluminum, or any other suitable material affixed to HDPE pipe 46. Hence, by the use of downward force, the driving tip 42 penetrates the soil and moves any obstructing objects aside while the water jetting out from orifices 44 will loosen the soil and lubricate the process allowing for more rapid and easy insertion. In this aspect of the invention, an outer tube and an inner tube are used in combination to provide a means of giving exterior strength for support while driving into the ground, as well as providing concentric flow within the heat exchanger. Since the driving action does not require a very high force for insertion into the ground, the outer tube provides sufficient strength.
Still referring to
During the insertion process for the two piece heat exchanger aspect, the outer pipe or tube will be inserted into the ground first. In this aspect, water jets are supplied with water throughout the entire volume of the outer pipe. Either during manufacture, or following the insertion, an inner pipe with the downhole plug would be inserted into the outer pipe thereby creating an annular flow profile. In this aspect, the downhole plug will be designed to seal the end of the inner pipe and also to self center the inner pipe by directing the bottom end of the plug into the center of the driving tip by using a male shape cone feature on the plug. To aid in the self centering feature, a female cone is formed on the driving tip, as seen in
This two piece aspect of the invention, using only the outer tube for ground insertion and removing the driving tip when insertion is completed, may be especially applicable in installing electrical races or irrigation piping under sidewalks and roadways, thereby providing other uses for the present device. Although the one piece design is unlikely to be used for these purposes, the two piece design using the inner tube for ground insertion and ancillary sidewall holes may be used for the production of water point wells, such as those used for drinking water or irrigation water. These types of installations are yet another aspect of the use for the present invention.
As shown in
In order to increase the efficiency of this heat exchanger device, thermal insulation may be added on either the inside or the outside of the inner tube to reduce heat transfer between the downflow fluid and the upflow fluid during the heat exchanger operation. Needless to say, in the heating cycle of a ground source heat pump, the downflow fluid will be at a lower temperature than the upflow fluid, as the upflow fluid will pick up heat from the ground on its way back up. For example, in a northern Michigan application, the downflow fluid would have had the heat removed from it during the heat pump operation, thereby lowering the temperature of the downflow fluid to between about 35 and 50 degrees, while the heat exchanger fluid as it is flowing up will pick upheat to raise the temperature of the heat exchanger fluid to between about 45 to 60 degrees Fahrenheit. This temperature gradient will allow the heat pump to remove the heat from the heat exchanger fluid, and this cooled fluid then becomes the downflow fluid. This is why the downflow fluid is at a lower temperature than the up flowing fluid. Without this temperature gradient, the geothermal heat pump would not be able to operate. As part of the design for both the one piece and two piece variations, the entire device can be engineered and designed to have laminar flow in the downflow inner pipe, thereby reducing heat transfer between the downflow and the upflow fluid streams, as well as reducing pressure drop for lower pump power requirements. This also provides a turbulent flow in the upflow annular area between the inner pipe and the outer pipe to increase heat transfer with the outer pipe and therefore the ground. These features in combination and singly improve the efficiency of the system.
Both one piece and two piece variations preferably use a multiple heat exchanger fluid downflow escape outlet to allow heat exchange fluid to pass from the inner pipe to the outer pipe. These outlets or perforations are described more fully hereinbelow with respect to
For clarity,
Looking next to
With combined reference to
Looking now to
As for using the present invention in accordance with a new business model, it is envisioned that this invention and its methods are particularly suitable for franchising to contractors wishing to have a new business for low cost direct insertion of any type of underground tubing, but of course especially for ground loop heat exchangers in order to enable usage of geothermal heat pump heating and cooling systems for buildings. As the present method of insertion by utilizing the inventive devices of the driving tip with water jet orifices and the concentric tube upflow and downflow heat exchanger system, the direct labor and materials costs are dramatically reduced over the prior art. Conventional methods for inserting heat exchangers are disruptive to the neighboring landscape and potentially building foundations and/or swimming pools, and etc. The present invention is much quieter, and merely disrupts a few inches of the topsoil rather than requiring massive digging and boring operations. In fact, even the equipment that is made possible by the present invention of the driving tip insertion device along with the concentric tubing is so much smaller and less weight, it can be rolled over septic tanks and sewer pipes that may be underground. Previously, the excavation and boring equipment utilized for inserting the ground loop heat exchanger could easily crack any underground pipes, plumbing or crack foundations when the vibration got to be too much if the machine got to close to a home, swimming pool, driveway, culverts, or the like.
Therefore, a novel business method is proposed for utilizing the services of an equipment leasing company to purchase the various aspects and/or variations of the compression and drive units described in greater detail hereinabove, along with the provision of the manufactured concentric tube and the novel driving tip to be attached to the bottom of the concentric tube.
The method of insertion may include two aspects, whether a first outer tube is initially inserted and then followed by the insertion of an inner tube which is kept in place by a spacer ring, or a single tube may be inserted that is a coextruded piece having three separate openings as described above. Any of the insertion equipment that is described with reference to
In that regard, the present invention may also be used in another aspect for simplifying the insertion of a monitoring device or for further investigational processes such as the use of the previously described novel driving tip to combine water jetting displacement capability with the novel driving process. My system can be used as a probe and has been found to be very useful in finding underground objects, such as septic tanks and the like, without the need for digging holes. Since the novel driving tip and the rest of the configuration of my invention can be used very quickly, utility can be realized for many operations. Given the system's ability to quickly penetrate the ground, the outer tube can be inserted into the ground by only using human power and up-and-down motion. In this aspect, the quick insertion feature may be useful for finding objects that are up to 10 feet underground or, if deeper insertion is needed, it may be utilized with the more highly mechanized installation trailer described hereinabove using my water jetting feature in combination with the up-and-down motion to probe for objects at levels deeper than 10 feet.
Looking now at
Next we refer to
Using this simple design, heat exchangers that are closed loop systems, whether using water, or a water and anti-freeze solution or a refrigerant-based fluid or gas, may be inserted into the outer tube with the remaining space in the tubing being filled with water, the water and anti-freeze solution, or it actually may be filled with grout to facilitate heat transfer between outer tube 606, which is in thermal communication with the ground, and any heat exchanger or sensor that may be inserted into the outer tube.
In its most simple design, and by using only the outer tube and the water jetting displacement capability of my novel driving tip, my system can be also used as a probe useful for finding underground objects, such as the location of a septic tank. This operation can be done quickly and efficiently without the need for digging holes, which is the current technology. Given my system's ability to quickly penetrate the ground, the outer tube can be inserted into the ground by only using human power and emulating the up and down motion for shallow probes, or it may utilize the installation trailer described herein above using water jetting to probe for objects it deeper locations.
Therefore, in its most preferred aspect for use in the field of geothermal installations, disclosed is a direct insertion ground loop heat exchanger, comprising an at least partially hollow pointed driving tip having at least one orifice therethrough for dispersing water through the driving tip to ease insertion into the ground, such that placing the driving tip onto the ground and urging water through the orifices will separate and part the ground easily, permitting the insertion of the driving tip deeper and deeper into the ground and a hollow outer tube having an inner diameter attached to the driving tip, said tube extending upwardly from out of the driving tip and terminating above the ground for accessibility. The driving tip is preferably made of at least a semi-rigid material, such that the driving tip will not collapse upon insertion into the ground. The at least semi-rigid material is preferably made of a strong material resistant to crushing, such as a metal, or a high durometer plastic, a ceramic, or any other suitable hard material, or any combination thereof.
The at least one orifice is preferably evenly distributed around the outside surface of the driving tip in order to ensure even insertion into the ground. Further, the outer tube is preferably made of a semi flexible material, such as polyethylene, polyurethane, rubber, or any other suitable high-strength plastic. Within the outer tube, a concentrically located inner tube may be found within the inner diameter of the hollow outer tube, and within the concentrically located inner tube may be a heat exchanger, such that fluid can be urged downward into the warmer portion of the earth between the hollow outer tube and the concentrically located inner tube, and where the heat that is transferred from the warm earth to the heat transfer fluid flows back up to the surface for heat extraction. This fluid may be a heat transfer fluid as described more fully hereinabove, in order to carry heat from deep in the earth back up to the surface such that the heat may be extracted for geothermal implications.
In summary, numerous benefits have been described which result from employing any or all of the concepts and the features of the various specific embodiments of the present invention, or those that are within the scope of the invention.
The foregoing description of various preferred aspects of the invention have been presented for purposes of illustration and description. It is not intended to be exhaustive, nor to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings with regards to the specific aspects. These various aspects were chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various aspects and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims which are appended hereto.
INDUSTRIAL APPLICABILITYThe present invention finds utility for inserting a hollow tube into the ground without disturbing large amounts of real estate, and more particularly, the present invention is especially useful for the insertion of vertical ground loop heat exchanger installations.
Claims
1. A direct insertion ground loop heat exchanger, comprising:
- an at least partially hollow pointed driving tip having at least one orifice therethrough for dispersing water through the driving tip to ease insertion into the ground, such that placing the driving tip onto the ground and urging water through the orifices will separate and part the ground easily, permitting the insertion of the driving tip deeper and deeper into the ground; and
- a hollow outer tube having an inner diameter attached to the driving tip, said tube extending upwardly from out of the driving tip and terminating above the ground for accessibility.
2. The driving tip of claim 1, comprising at least a semi-rigid material, such that the driving tip will not collapse upon insertion into the ground, and wherein said at least semi-rigid material made of a high durometer plastic, a metal, a ceramic, or any other suitable hard material, including combinations thereof.
3. The driving tip of claim 1, wherein the at least one orifice is evenly distributed around the outside surface of the driving tip in order to ensure even insertion into the ground.
4. The hollow outer tube of claim 1, wherein said outer tube is made of a semi flexible material, such as polyethylene, polyurethane, rubber, or any other suitable high-strength plastic.
5. The hollow outer tube of claim 1, further comprising a concentrically located inner tube within the inner diameter of the hollow outer tube.
6. The hollow outer tube of claim 1, further comprising a heat exchanger with the concentrically located tube inside the hollow outer tube, such that fluid can be flowed between the hollow outer tube and the concentrically located inner tube.
Type: Application
Filed: May 13, 2015
Publication Date: Sep 21, 2017
Inventor: Charles J Cauchy (Traverse City, MI)
Application Number: 15/310,378