CN101886851A - Ground-source heat pump vertical-pipe heat exchanger technology - Google Patents

Abstract

The invention relates to a ground-source heat pump vertical-pipe heat exchanger technology which comprises a ground-source heat pump underground vertical-pipe heat exchanger drill hole (1), water inlet and outlet pipes (2 and 3) in the drill hole and a drill hole backfill material (4). The technology is characterized by comprising the following four technical features: the water outlet pipe (3) (or the water inlet pipe (2)) buried in the drill hole is made of a thermally weldable composite pipeline or a composite structure pipeline of which the heat conductivity coefficient is less than 0.3W/M.S. The water inlet pipe (2) (or the water outlet pipe (3)) is made of a thermally weldable composite pipeline of which the heat conductivity coefficient is more than 0.5W/M.S. The drill hole backfill material (4) is made of at least one of graphite and heat-conducting carbon black and other components, wherein the weight percentage of the graphite and heat-conducting carbon black is 0.1-5%, and other components include sands or grits; or the drill hole backfill material (4) is made of a mixture of granular materials and other materials, wherein the granular materials are formed by mixing and granulating graphite powder or heat-conducting carbon black of which the weight percentage is 0.1-50% and binding materials (such as cement), sands or grits. The vertical water inlet and outlet pipes (2 and 3) are laid by using a bag type pipe-laying device (5), vertical water inlet and outlet pipes (2 and 3) are sufficiently and uniformly separated, and the sectional perimeter of the bag type pipe-laying device (5) is 1-20% larger than that of the vertical-pipe drill hole (1); and the drill hole backfill material (4) is backfilled in the bag type pipe-laying device (5).

Description

Ground-source heat pump vertical-pipe heat exchanger technology

Technical field

The present invention is a ground-source heat pump vertical-pipe heat exchanger technology, belongs to the energy, material and air-conditioning technical field.

Background technology

The earth-source hot-pump system of underground buried tube heat exchange, one that is called as 21 century is the air-conditioning technical that has development prospect most of feature with energy-conservation and environmental protection, vertical-pipe heat exchanger is the most general the most frequently used form.Ground-source heat pump vertical-pipe heat exchanger is the core of earth source heat pump, is that the Cooling and Heat Source of earth source heat pump is obtained the efficient place.Not only determine the efficiency of machine set system, and determining underground ground energy utilization ratio.And then initial cost and operating cost have been determined.The heat exchange thermal resistance of the underground each several part of earth source heat pump is the basic of this problem, and the thermal resistance of underground ground body beyond boring almost can't change, and we can control, and can to change be the size of boring internal thermal resistance part.According to studies show that, (at present under the technical situation) internal thermal resistance of holing is usually taken up an area of half of following heat exchanger thermal resistance, and the technology maturation degree of which ground-source heat pump vertical-pipe heat exchanger just depends on the degree that minimizes of the internal thermal resistance of holing.Present technique promptly is to produce in line with this target.

In the present boring 1 there be technology, water inlet pipe andwater outlet pipe 2,3 adopts heat conductivility macromolecular material (HDPE) preferably in the boring 1, increase the pipe laying spacing as far as possible and adopt Geothermal spring to be in charge of, improve the heat conductivility of thebackfilling material 4 in the boring 1, adopt thermal conductivity sandy soil prescription preferably.Improve the heat conductivility of thebackfilling material 4 in the boring 1, adopt mixing such as bentonite, sandstone, it is reported that abroad high energy reaches 2--3W/MS, but the proportioning complexity, operation is difficult for.The thermal conductivity factor ofconventional backfilling material 4 is at 1.0W/MS.Though the thermal conductivity factor of HDPE pipeline material is high in macromolecular material, also has only 0.45W/MS, heat exchanging remains the undesirable heat conductor of employing, and the ratio of its shared underground heat exchange entire thermal resistance is also not little.But there is the hot reflux of water inlet pipe andwater outlet pipe 2,3 in perpendicular simultaneously pipe laying heat exchange, or cries hot short circuit, along with the increase of tubing andbackfilling material 4 heat conductivilitys will strengthen.Therefore this is the problem of a pair of contradiction, calculates from theory, if the thermal conductivity factor of material doubles in existing boring, but the heat exchange result who brings might not increase.Perpendicular pipe laying buried depth was between 40--120 rice during engineering was used at present, and along with the increase of pipe laying buried depth, the hot reflux problem can increase the weight of, and therefore, avoids the hot reflux problem even more important for buried pipe.

The summary of the invention and the specific embodiment

Based on the present present situation of present ground-source heat pump vertical-pipe heat exchanger technology, content of the present invention is summarised as: add the heat conductivility that the heat conduction auxiliary agent increases interior heat exchange tubing of boring and backfillingmaterial 4 on the one hand, use pocket type stringing device, fully rationally stringing makes the equivalent diameter of pipe laying big as far as possible; Adopt adiabatic tubing to reduce to exist the heat transfer property of hot reflux pipeline on the other hand, reduce hot reflux.As follows in concrete:

In the water inletpipe 2 of vertical-pipe heat exchanger, theoutlet pipe 3 both one of part pipeline section or whole pipeline sections of (and having only one): but adopt composite material conduit or the composite construction pipeline of thermal conductivity factor less than the thermal welding of 0.3W/MS.In thewater inlet pipe 2 of vertical-pipe heat exchanger, theoutlet pipe 3 both one of (and having only one) but adopt the composite material conduit of thermal conductivity factor greater than the thermal welding of 0.5W/MS.Boring backfilling material 4 is: adopt graphite or heat conduction carbon black among both at least a mass content be 0.1-5%, comprise the material of sand or stone in other composition; Perhaps adopting mass fraction is powdered graphite or the heat conduction carbon black of 0.1-50%, mixes granulation afterwards with jointing material (for example cement), sand or microlith, use again this granular materials or with the composite material of other material.Ground-source heat pump vertical-pipe heat exchanger also comprises pockettype stringing device 5, make the heat exchange pipeline of U type pipe or spider shape pipe and pocket type stringing device is elongated evenly adheres to, adopt pocket type stringing device stringing to make perpendicular pipe laying full and uniform separately, and the section girth of pocket type stringing device is greater than buried pipe bit pore cross section girth 1-20%; 4 backfills of boring backfilling material are in pockettype stringing device 5.

But thermal conductivity factor is less than the composite material conduit of the thermal welding of 0.3W/MS, and one of its implementation is that PE material and thermal conductivity factor materials with smaller are compound, as compound with the PVC material, and at pipe joint thermal welding place employing HDPE high-load pipeline section; Perhaps the inboard low heat conductivity macromolecular material that adopts of HDPE is adopted in the pipeline outside.But comprise the insulation heat insulating construction and make the composite construction pipeline of the overall equivalent heat conductivity of pipeline material less than 0.3W/MS and thermal welding, one of its implementation is: the interior outside of pipeline is the load macromolecular material, wherein but the outside is the thermal welding macromolecular material, the centre connects by rib and supports, rib can be insulation material or gas between the rib for cross rib, perpendicular rib, diagonal rib or netted rib.But thermal conductivity factor is greater than the composite material conduit of the thermal welding of 0.5W/MS, one of its implementation is: but the material that adopts the good nano aluminum nitride of the macromolecular material of thermal welding and thermal conductivity or graphite or ketjenblack EC or wherein at least a material of carbon fiber to be composited, and the mass content of nano aluminum nitride or graphite or ketjenblack EC is between 0.01-10%.But what comprise the augmentation of heat transfer structure makes the composite construction pipeline of the overall equivalent heat conductivity of pipeline material greater than 0.5W/MS and thermal welding, and one of its implementation is: but the pipeline that at least a material constitutes among the macromolecular material of thermal welding and reticulated aluminum fiber or copper fiber or the carbon fiber three.Pockettype stringing device 5 materials are thermal conductivity factors greater than the fabric of 1.5W/MS or the thermal conductivity factor polymer composite thin film greater than 1.5W/MS.Pockettype stringing device 5 is a web form, and the mesh size should satisfy 80% above backfilling material and can not pass through.A kind of specific embodiments of boringbackfilling material 4 is: graphite (mass fraction 1-10%), cement (mass fraction 1-30%), water and sand (or stone) mixing granulation, the density of the particle of assurance granulation is mixed the back backfill again and is gone into boring 1 greater than water with powdered graphite, cement, water.

Principle

In the water inletpipe 2 of vertical-pipe heat exchanger, theoutlet pipe 3 both one of part pipeline section or whole pipeline sections of (and having only one): but adopt composite material conduit or the composite construction pipeline of thermal conductivity factor less than the thermal welding of 0.3W/MS.Its principle is: when the heat conductivility that improvesboring backfilling material 4, the hot reflux degree that the water inletpipe 2 of vertical-pipe heat exchanger, outlet pipe are 3 will increase, for fear of hot reflux, need. adopt the insulation insulated piping at the serious pipeline section of hot reflux, but but the thermal conductivity factor of the polymeric pipe of the thermal welding of using at present is between 0.3--0.5W/MS, but therefore proposes here to adopt the composite material conduit or the composite construction pipeline of thermal welding to reach thermal conductivity factor less than 0.3W/MS.Both can only have one to be to hang down to cause hot pipeline inwater inlet pipe 2, theoutlet pipe 3, and another root must be the good pipeline of thermal conductivity.This also be inwater inlet pipe 2, theoutlet pipe 3 both one of (and having only one): but adopt the reason of thermal conductivity factor greater than the composite material conduit or the composite construction pipeline of 0.5W/MS thermal welding.

Graphite or heat conduction carbon black, because of its good heat-conducting, and also cheap abundant, a spot of adding just can reach the high heat conductivility of material monolithic, therefore proposes to adopt graphite or heat conduction carbon black as composition in backfilling material 4.But its proportion is less simultaneously, and therefore energy content is not excessive, otherwise can be difficult to backfill because of proportion kicks the beam.Here propose with itself and cement, sand, stone mixing granulation, and assurance granulation proportion is greater than water, be for backfilling material can be successfully, backfill goes into to hole effectively.

Pockettype stringing device 5 is in order to guarantee that the perpendicular heat exchange pipeline that buries can evenly and be close to boring 1 and arrange.According to theoretical research, when many heat exchange pipelines as far as possible during dispersed placement, equivalent pipe diameter maximum, the hot reflux minimum, exchange capability of heat at this moment is the strongest.

Description of drawings

Accompanying drawing is the schematic diagram of the typical embodiments of ground-source heat pump vertical-pipe heat exchanger technology.

Reference numeral: 1-boring 2-water inlet pipe (or outlet pipe) 3-outlet pipe (or water inlet pipe) 4-boring backfilling material 5-pocket type stringing device

Claims (8)

1. ground-source heat pump vertical-pipe heat exchanger technology, ground-source heat pump vertical-pipe heat exchanger comprises pipe laying and boring backfilling material in the underground boring of earth source heat pump, the boring, and it is characterized in that: ground-source heat pump vertical-pipe heat exchanger technology comprises one of following four technical characterictics at least:

Technical characterictic one: when the pipe laying form of vertical-pipe heat exchanger is U type pipe or spider shape pipe (being that many branched pipes link to each other with a collector), in its water inlet pipe, the outlet pipe both one of part pipeline section or whole pipeline sections of (and having only one): but adopt the composite material conduit of thermal conductivity factor less than the thermal welding of 0.3W/MS; But or adopt and to comprise the insulation heat insulating construction and make the composite construction pipeline of the overall equivalent heat conductivity of pipeline material less than 0.3W/MS and thermal welding.When the pipe laying form of vertical-pipe heat exchanger is sleeve pipe or helix tube form, interior pipe: but adopt the composite material conduit of thermal conductivity factor less than the thermal welding of 0.3W/MS; But or adopt and to comprise the insulation heat insulating construction and make the composite construction pipeline of the overall equivalent heat conductivity of pipeline material less than 0.3W/MS and thermal welding.

Technical characterictic two, when the pipe laying form of vertical-pipe heat exchanger is U type pipe or spider shape pipe (being that many branched pipes link to each other with a collector), water inlet pipe, outlet pipe both one of (and having only one): but adopt the composite material conduit of thermal conductivity factor greater than the thermal welding of 0.5W/MS; But or adopt comprise the augmentation of heat transfer structure make the composite construction pipeline of the overall equivalent heat conductivity of pipeline material greater than 0.5W/MS and thermal welding.When the pipe laying form of vertical-pipe heat exchanger is sleeve pipe or helix tube form, outer tube: but adopt the composite material conduit of thermal conductivity factor greater than the thermal welding of 0.5W/MS; But or adopt comprise the augmentation of heat transfer structure make the composite construction pipeline of the overall equivalent heat conductivity of pipeline material greater than 0.5W/MS and thermal welding.

Technical characterictic three, the boring backfilling material is: adopt graphite or heat conduction carbon black among both at least a mass content be 0.1-5%, comprise the material of sand or stone in other composition; Perhaps adopting mass fraction is powdered graphite or the heat conduction carbon black of 0.1-50%, contains the ore deposit particle with jointing material (for example cement), soil or sand or microlith or other and mixes the back granulation, use again this granular materials or with the composite material of other material.

Technical characterictic four, ground-source heat pump vertical-pipe heat exchanger also comprise pocket type stringing device.Pocket type stringing device is soft bag shape overcoat, makes the heat exchange pipeline of U type pipe or spider shape pipe and pocket type stringing device is elongated evenly adheres to, and the section girth of pocket type stringing device is greater than buried pipe bit pore cross section girth 1-20%; The backfill of boring backfilling material is in pocket type stringing device.

2. ground-source heat pump vertical-pipe heat exchanger technology according to claim 1, but thermal conductivity factor is less than the composite material conduit of the thermal welding of 0.3W/MS, one of its implementation is that PE material and thermal conductivity factor materials with smaller are compound, as compound with the PVC material, and at pipe joint thermal welding place employing HDPE high-load pipeline section; Perhaps the inboard low heat conductivity macromolecular material that adopts of HDPE is adopted in the pipeline outside.

3. ground-source heat pump vertical-pipe heat exchanger technology according to claim 1, but comprise the insulation heat insulating construction and make the composite construction pipeline of the overall equivalent heat conductivity of pipeline material less than 0.3W/MS and thermal welding, one of its implementation is: the interior outside of pipeline is the load macromolecular material, wherein but the outside is the thermal welding macromolecular material, middle connect and support ectonexine by rib, rib can be insulation material or gas between the rib for cross rib, perpendicular rib, diagonal rib or netted rib.

4. ground-source heat pump vertical-pipe heat exchanger technology according to claim 1, but thermal conductivity factor is greater than the composite material conduit of the thermal welding of 0.5W/MS, one of its implementation is: but the material that adopts the good nano aluminum nitride of the macromolecular material of thermal welding and thermal conductivity or graphite or ketjenblack EC or wherein at least a material of carbon fiber to be composited, and the mass content of nano aluminum nitride or graphite or ketjenblack EC is between 0.01-10%.

5. ground-source heat pump vertical-pipe heat exchanger technology according to claim 1, but what comprise the augmentation of heat transfer structure makes the composite construction pipeline of the overall equivalent heat conductivity of pipeline material greater than 0.5W/MS and thermal welding, and one of its implementation is: but the pipeline that at least a material constitutes among the macromolecular material of thermal welding and reticulated aluminum fiber or copper fiber or the carbon fiber three.

6. ground-source heat pump vertical-pipe heat exchanger technology according to claim 1, pocket type stringing modulator material are thermal conductivity factors greater than the fabric of 1.5W/MS or the thermal conductivity factor polymer composite thin film greater than 1.5W/MS.

7. ground-source heat pump vertical-pipe heat exchanger technology according to claim 1, pocket type stringing device is the holey form, the mesh size should satisfy 80% above backfilling material and can not pass through.

8. ground-source heat pump vertical-pipe heat exchanger technology according to claim 1, a kind of specific embodiments of boring backfilling material is: graphite (mass fraction 1-10%), cement (mass fraction 1-30%), water and sand (or stone) mixing granulation, the density of the particle of assurance granulation is mixed the back backfill again and is gone into boring greater than water with powdered graphite, cement, water.

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