FI120892B - Pipes and systems for utilization of low energy - Google Patents

Description

Pipe and system for low energy recovery

Background of the Invention

The invention relates to the utilization of low energy and more particularly to a system in which thermal energy is transmitted by a terminal device, such as a heat pump from the ground, rock or water, via a transmission fluid.

By low energy, here is meant the low temperature of the heat source, which may for example be + 2- + 10 degrees. Geothermal heat provided by a heat source such as earth, rock or water will be described here as low energy. The utilization of low energy from land, rock or water has generally been to heat the building and the hot water, for example by using a heat pump and a brine circuit. The operating principle of such a geothermal system is similar to that of a freezer, but the reverse is where the system cools the ground and heats, for example, a water heater. Often 2 to 4 units of heat are obtained per unit of electrical energy used. The efficiency is significantly better than in direct electric heating. In cold climates, the heating energy consumption of buildings is considerable. The use of geothermal energy is increasingly profitable as electricity and oil costs rise.

20 Such a low-energy system can also be used as an alternative for indoor cooling, for example by circulating cool transmission fluid from the ground, for example, through chilled beams or the like.

One common way of absorbing heat is by installing a horizontal pipeline approximately 25 feet deep. However, such piping requires a large surface area, so that it can only be used on large sites. The collection circuit may be on land or in water. Placing the horizontal pipeline on the ground requires digging the pipeline across the entire collection area. Circuit pipe loops should be at least 1.5 m apart so that adjacent loops do not interfere with each other's heat uptake. Laying a horizontal pipe in a park, for example, is difficult without damaging the plants and root system.

A thermal well is another common way of absorbing heat. The hole is drilled in the rock. A thermal well, ie a well, is usually drilled vertically. Very little surface area is required for the thermal well compared to the horizontal 35 manifold. However, there may be a significant tens of meters of loose soil on the rock. The bulk section should be provided with a protective pipe, which increases the cost. Thus, soil with a thick layer of loose soil restricts the placement of the thermal well. The heat output in a thermal mine is generally higher than the horizontal pipeline. The heat recovery from the thermal well depends in part on the flow of groundwater. However, it is impossible to estimate groundwater flow without implementing expensive drilling.

A third way of heat uptake is to place the heat inlet pipeline at the bottom of a lake or other body of water, whereby heat is transferred from the bottom sediment and water to the transmission solution. The pipeline can be transported to the water in the ground, but there must be separate trenches for the inlet and return pipes. Plumbing is easy to install at the bottom of the water. However, the solution-filled tube is lighter than water and tends to rise upwards. Elevated pipe sections can cause air pockets that can hinder circulation. The tube must therefore be anchored to the bottom with sufficient weights. Bottom piping is also prone to breakage. The boat anchor or the like can seize the pipeline and break the pipe. At the water's edge, the inlet and return pipes will be dug to prevent ice from breaking the pipeline.

The choice between these three methods depends on the location, area and soil available. Low-energy networks are designed to be implemented in such a way that several houses have one common larger collector circuit.

Brief Description of the Invention

It is therefore an object of the invention to provide a pipe and system so that the above problems can be solved. The object of the invention is achieved by 25 pipes and a system characterized by what is stated in the independent claims. Preferred embodiments of the invention are claimed in the dependent claims.

The invention is based on the fact that a low energy receiving circuit, such as, for example, a ground source heat pump circuit, is formed by an inner tube 30 and an outer tube surrounding it, the outer periphery of which has inwardly extending recess portions. The outer end of the outer tube is sealed, allowing the solution to move from the inner tube to the outer tube depending on the flow nozzle or vice versa.

One object of the invention is to provide a system for implementing a low-energy receiving circuit of a terminal.

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Another object of the invention is to provide a tube for implementing a low energy receiving circuit of the terminal.

According to one embodiment of the object of the invention, the system comprises a terminal and a ground circuit in which heat bound to the circulating fluid is transferred by a geothermal pump, for example, to a heating circuit in the property. The earth circuit is implemented with the inner tube and the surrounding outer tube so that the outer end of the outer tube is closed, allowing the solution, depending on the flow direction, to move from the inner tube to the outer tube or vice versa.

10 The system's ground circuit can be positioned horizontally by digging for example a ditch. The pipe of the invention enables the circuit to be implemented without a separate return pipe. For the earth circuit, the length of the trench to be excavated will decrease as a function of the outer surface area of the outer pipe.

The tube can be placed in the soil horizontally downwards by drilling inclined-15. Drilling can be done not only on the rock but also on the ground between the rock and the ground, since no separate trench is required for the return pipe of the circuit. The pipe of the invention enables the pipe to be placed under water where the pipe is protected. When the tube bore is drilled obliquely downwards, the outer end of the tube is deeper, which also has a higher temperature. Tilting the pipe downwardly allows the air to escape from the pipeline. The pipe inclination can be varied according to the soil. The pipe does not have to be straight, but can be turned and bent in a way that allows for drilling. The pipe of the invention enables the realization of the earth circuit under watercourses, parks, roads and even buildings, since no separate return pipe is required.

According to another embodiment, the ground circuit comprises a body conduit connected to the terminal, to which two or more of said tubes having an inner tube and an outer tube are connected. The main piping may be implemented separately, but in this case heat transfer should be minimized by separating the pipes or isolating the heated transmission fluid 30. The number and length of the pipes can be varied according to the area used and the soil. It should be noted that in addition to the pipe according to the invention, ground circuits implemented in conventional manner can be connected to the main piping.

According to another embodiment of the object of the invention, the medium 35 is moved in the inner tube of the tube comprising the outer tube and its inner inner tube away from the heat pump and received ............ - 4 ..... ........ ..

from the space between the outer surface of the inner tube to the inner surface of the outer tube surrounding the heat pump, the heat pumped fluid. The hole drilled obliquely or directly downwards has a higher temperature at the end of the pipe. By moving the medium as cold as possible to a lower location, the maximum temperature difference between the medium and the extracellular material, such as soil, water or filler material, is obtained at the end of the tube. The large temperature difference allows efficient transfer of thermal energy to the transmission fluid.

According to yet another embodiment of the invention, the tube 10 comprises an outer tube within which an inner tube may be disposed. The outer surface of the inner tube is arranged to be separated from the inner surface of the outer tube by means of recess portions arranged in the outer tube. The recess portions may be in the form of an outer tube that aligns the inner tube with the center of the outer tube.

The tube end is adapted to receive the end sealing end portion of the outer tube so that the fluid to be transported in the tube can move at one end depending on the flow direction from the inner tube to the outer tube or vice versa. Depending on the drilling equipment and methods, the pipe termination can be implemented in different ways. However, it is essential that the end portion only closes the end of the outer tube, so that the solution can move from one tube to another. The transfer fluid can be facilitated, for example, by the design of the end portion which directs the flow outwardly from the inner tube or vice versa.

The pipe material is, for example, polyethylene. For example, the outer tube may have a diameter of 100 mm and the inner tube may have a diameter of, for example, 40 mm. In this case, the outer tube provides, due to the larger outer periphery and the recess portions therein, with a larger surface area for transmitting energy to the delivery solution.

The volume between the inner surface of the outer tube and the outer surface of the inner tube relative to the volume of the inner tube can be increased by varying the diameter ratio of the tubes and the number and shape of the recess portions. The number of elongate recess portions is preferably at least three, whereby the inner one can be centrally located within the outer tube. The recess portions of the outer tube can also be implemented in a circular fashion, whereby the flow channels formed between the recess portions 35 become longer than the flow channels of the direct recess portions. Centering the Inner Pipe ............ ................ 5 .................. ..................

a smaller number of recess portions may be provided in the outer tube when the recess portions advance helically in the tube. It is possible to center the inner tube even with one recess portion having a dense thread.

5 Note that pipe materials and diameters may vary. The inner tube may also be insulated to reduce heat transfer between the inner and outer tubes. However, there is a large area difference between the outer surface of the inner tube and the outer surface of the outer tube, whereby insulating is not necessary for the operation of the tube according to the invention. However, the inner tube 10 may be insulated if it is desired to further reduce heat transfer between the tubes. Insulation of the inner tube can be accomplished in different ways depending on the technique used to make the tube. Instead of or in addition to separate insulation material, the thickness of the inner tube, the material, etc. can be varied. For example, the inner tube may be made thicker or two walls, whereby the inner tube has better insulating properties than the outer tube so that the transfer of heat energy between the tubes fluid is less than between the fluid in the outer tube and the surrounding ground or water.

The inner tube may be insulated only from the upstream end, whereby the downstream vir-20 rate of velocity increases with that portion of the outer tube. This is where most of the energy transfer takes place where it is most efficient. The isolation of the upstream end can then be accomplished during installation by, for example, inserting another tube onto the inner tube.

The most common additives to be added to the delivery fluid are, for example, alcohol or potassium formate. The main function of the additive is to lower the freezing point. The new method provided by the tube of the invention allows the use of a solution with a lower alcohol content because the cooler fluid is transported in an inner tube surrounded by an already warmed fluid in the outer tube. Thus, the invention 30 allows even the use of additive-free water as a delivery fluid. With the end of the tube at a depth below the baseline, the temperature at the lower depth is higher than the baseline. In this case, the temperature difference between the soil temperature at the end of the pipe and the temperature of the transfer fluid of the inner pipe is as large as possible. The large temperature difference accelerates heat transfer to the solution passing through the outer tube. The heated transmission fluid in the outer tube surrounds the transfer fluid in the inner tube and prevents it from freezing.

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BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described in connection with preferred embodiments, with reference to the accompanying drawings, in which:

Figure 1 shows an embodiment of the system 5 according to the present invention;

Figure 2 shows a second embodiment of the system according to the present invention;

Figure 3 shows a third embodiment of a system according to the present invention; Figure 4 shows a fourth embodiment of a system according to the present invention;

Figure 5 shows a fifth embodiment of a system according to the present invention;

Figure 6 shows a sixth embodiment of a system 15 according to the present invention;

Figure 7 shows an end view of an embodiment of a pipe according to the present invention;

Figure 8 shows the end of the tube of Figure 7 in which the inner tube is disposed; Figure 9 shows a second embodiment of a pipe according to the present invention as seen from the end;

Figure 10 shows the end of the tube of Figure 9 in which the inner tube is disposed;

Figure 11 is a front elevation view of the tube of Figure 9;

Fig. 12 shows a third embodiment of the pipe according to the present invention as seen from the end;

Fig. 13 shows the end of the pipe of Fig. 12 in which the inner pipe is disposed; Figure 14 shows a fourth embodiment of the pipe of the present invention, seen from the end;

Figure 15 shows the end of the tube of Figure 14 in which the inner tube is disposed;

Figure 16 shows a side view of one embodiment 35 of the pipe according to the invention; 7

Fig. 17 is a plan view showing the coupling member attached to the pipe of Fig. 16;

Fig. 18 is a plan view in which the coupling member is attached to the pipe of Fig. 16.

Detailed Description of the Invention

Referring to Figure 1, there is shown an embodiment of the system of the present invention, in which the tube 1 is placed horizontally below the ground. The tube is at a depth d, which may be, for example, 1.2 to 2 m. The terminal 3 utilizes the low energy accumulated in the piping 1 and transmits it to the house 2 by the transfer tube 31 where it circulates through the heating circuit 7 and returns via the transfer tube 32 back to the collection. Here, the pipe 1 is directly connected to the terminal 3. The terminal 3 may be, for example, a ground source heat pump. The figure shows a principal view of the tube 1 in which the cooled transmission fluid is conveyed along the inner tube 10 of smaller diameter away from the terminal 15. The medium moves at the outer end of the tube to the outer tube 20 having a larger diameter than the inner tube 10.

Figure 2 illustrates another embodiment of the system of the present invention in which the tube 1 of Figure 1 is inclined downwards. Here, the tube 1 is separate from the terminal 3. Thus, both the tube 1 and the terminal 3 can be placed in suitable locations. The pipe 1 is connected to the terminal 3 by means of transmission pipes 41 and 42. In the figure, the first end of the pipe 1 is at a depth of two meters and the outer end is at a depth of 50 meters near the rock. The difference between the depth of the upstream end and the depth of the downstream end may be several degrees. The slope of the pipe can be varied according to the depth of the rock. It is to be noted that the pipe 1 according to the invention can also be placed in a hole drilled in rock, and in a hole drilled in the ground and partially.

Fig. 3 shows a fifth embodiment of the system according to the present invention, in which the pipe 1 is disposed obliquely below the second building 2. The tube 1 is located in a hole drilled partly by a drill into the ground and partly by a rock. A separating part 110, such as a seal or the like, separating the rock and the soil is disposed adjacent to the pipe 1 to prevent the soil from mixing with groundwater. In this way, low energy provided by both soil and rock can be utilized, for example in the case of relatively thick soils.

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Figure 4 shows a sixth embodiment of a system according to the present invention in which pipe 1 is placed under water in a sediment layer from which it is advantageous to receive low energy. The tube 1 is then protected along its entire length under the bottom. Naturally, the pipe 1 according to the invention can also be placed in a water system with weights in a conventional manner.

Figure 5 illustrates a third embodiment of a system according to the present invention in which three tubes 1 are connected to the terminal device. The tubes 1 are connected to a manhole 80 from which they are connected to the terminal device 3 via transmission tubes 41 and 42. The number, length and slope of the tubes 1 may vary according to energy requirements and / or soil.

Figure 6 shows a fourth embodiment of a system according to the present invention in which several houses 2 or buildings are connected to the system. The pipes 1 are connected to the terminals 3 via the frame piping. 15 The size of the main piping 100, 200 may vary according to the pressure resistance. The pipes 1 are connected to the main piping 100, 200 by suitable connecting means 81 or via a manhole 80. The transmission fluid is returned to the pipeline 1 via manholes 80 or through direct connecting means.

Fig. 7 shows an embodiment of a tube 20 20 according to the present invention having five recess portions 220. The recess portion has two side walls 222 and an alignment wall 221 forming the bottom of the recess.

Figure 8 shows the tube 20 of Figure 7 where the inner tube 10 is located. The alignment walls 221 extend around the inner tube 10, approximating it to the outer tube 20. There is a small clearance T between the alignment walls 221 and the inner tube to facilitate installation of the inner tube 10 into the outer tube. . The inner tube 10 forms a single flow channel and the spaces between the recesses of the outer tube 20 form five outer flow channels 200.

30 After installation, this clearance T may escape due to sagging of the outer pipe. The pipe system according to the invention then provides a continuous pipe structure in which the inner pipe 10 also serves as a supporting structure for the outer pipe 20. This prevents the tube 20 from collapsing completely due to external pressure.

Figure 9 shows a second embodiment of the tube 20 according to the present invention, wherein the number of recesses 220 is six.

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Fig. 10 shows the pipe 20 of Fig. 9 in which the inner pipe 10 is located. The inner pipe forms a single flow channel and the spaces between the recesses of the outer pipe 20 form six outer flow channels 200.

Figure 11 shows the tube of Figure 9, in which the recesses 220 extend in the longitudinal direction of the tube 20.

Figure 12 illustrates a third embodiment of the tube 20 of the present invention, wherein the number of recesses 220 is six.

Figure 13 shows the tube 20 of Figure 12 in which the inner tube 10 is disposed. The inner tube 10 has different insulating properties here than the outer tube 20. The inner tube 10 may be provided with insulating material, but this is not necessary for the operation of the invention. However, the insulating properties of the inner tube 10 may be modified according to the manufacturing technique. The thickness or structure of the inner tube 10 may be altered if the tubes are made of the same material. The amount of thermal energy transferred between the pipes can then be reduced.

Fig. 14 shows a fourth embodiment of a tube 20 according to the present invention, wherein the number of recesses 220 is six. Figure 15 shows the tube 20 of Figure 14 in which the inner tube 10 is disposed.

Fig. 16 shows an embodiment of the pipe of the invention, in which the recesses 220 extend in a longitudinal direction along the pipe 20. Thus, the distance of the fluid flowing in the outer tube 20 increases with the number of threads. In the case of dense threading, the fluid may be conveyed through one or two flow channels 200 to one end of the pipe.

Fig. 17 is a partial view of an embodiment of a pipe end portion 5 of the present invention wherein the flow is from an inner tube 10 to an outer tube 20 having recess portions 220 of the invention. Arrows illustrate the flow direction. It should be noted that the flow direction may also be implemented in the opposite direction. The end portion can be secured to the tube in suitable ways, for example by welding.

Fig. 18 is a partial view of an embodiment of a pipe end portion 5 of the present invention wherein the flow is from an inner tube to an outer tube 20 having recess portions 220 of the invention. Here, recess portions 220 are longitudinal to the tube. The arrows depict 10 flow directions in the flow channels 200. It should be noted that the flow direction can also be implemented in the opposite direction.

It will be obvious to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims.

Claims (9)

A tube for utilizing low energy in a system in which a circular circuit is formed by an inner tube (10) and an outer tube 5 (20) surrounding it, characterized in that the outer periphery of the tube (20) has recess portions (220) extending in the longitudinal direction of the tube. (220) being open to the peripheral portion so that thermal energy can be transferred between the fluid to be transferred in the tube (20) and the surrounding material both through the walls (220) of the recess portion (220) closer to the rotation axis of the tube (20); ), the alignment wall (221) closest to the axis of rotation acting as a position determining member for the inner tube (10) to be inserted into the tube (20). Pipe according to Claim 1, characterized in that the pipe (20) comprises at least three recess portions, such that there is a space in the center of the pipe (20) in which the inner pipe (10) can be located. A pipe according to claim 1 or 2, characterized in that the recess portion (220) in the pipe (20) proceeds in a spiral manner in the longitudinal direction of the pipe. A pipe according to any one of the preceding claims, characterized in that the wall thickness of the recess portion (220) is smaller than the wall thickness of the outermost section of the pipe. A pipe according to any one of the preceding claims, characterized in that the recess portion (220) in the pipe (20) is substantially U-25 shaped. A low energy recovery system comprising: - a terminal device (3), and - a ground circuit in which low energy bound to the fluid circulating in the pipeline is utilized by the terminal device (3), the earth circuit 30 being implemented by the inner tube (10) and the outer tube (20) the outer end of the outer tube (20) being closed so that the solution can move depending on the flow direction from the inner tube (10) to the outer tube (20) or vice versa, characterized in that where the outer periphery of the outer tube (20) longitudinally extending 35 recess portions (220), the recess portion (220) being open to the peripheral portion so that thermal energy can be transferred between the fluid to be transferred in the tube (20) and the tube surrounding the periphery of the tube (20) piercing e itself, and wherein the alignment wall (221) closest to the axis of rotation of the recess portion (220) serves as a member defining the position 5 of the inner tube (10) disposed in the tube. System according to Claim 6, characterized in that the tube having the inner tube (10) and the outer tube (20) is directed downwards from the horizontal direction. System according to Claim 6 or 7, characterized in that the ground circuit further comprises a main pipeline connected to the terminal, to which two or more of said pipes having an inner pipe (10) and an outer pipe (20) are connected. System according to Claim 8, characterized in that the system further comprises frame pipes (100, 200) to which the inner pipes (10) and the outer pipes (20) are connected via manifolds (80) or connecting means (81).