CN114909827A - Novel ground source heat pump heat exchanger system and application method thereof - Google Patents

Description

A new type of ground source heat pump heat exchanger system and its application method

technical field

The invention belongs to the field of ground source heat pumps, in particular to a novel ground source heat pump heat exchanger system and an application method thereof.

Background technique

Among various renewable energy sources, geothermal energy is considered to be one of the most environmentally friendly and efficient energy sources for space heating and cooling. Geothermal energy has great potential as a directly usable energy type, especially when combined with ground source heat pump systems. Ground-coupled heat pump (ground source heat pump) system, as a renewable energy technology, has received increasing attention due to its high energy efficiency and environmentally friendly space cooling and heating mechanism. Ground source heat pump systems bury pipes underground to form ground heat exchangers ( Heat Exchanger). By using a circulating fluid connected to a heat pump, heat is extracted from the ground or released through pipes buried in the ground and used for heating and air conditioning of buildings. Ground source heat pump systems are not only suitable for residential buildings, but also for office buildings.

Among the various types of heat exchangers, vertical heat exchanger systems are more popular than horizontal heat exchangers for residential or commercial buildings that require substantial geothermal heating or cooling capacity within a limited installation area. Despite the higher installation costs, vertical systems have the advantage of requiring less installation area, better heat transfer performance and higher energy efficiency compared to horizontal systems. Vertical heat exchangers consist of plastic pipes (common materials are polyethylene or polypropylene), refrigerant and backfill material, which can reduce the thermal resistance between the pipes and the ground and make good contact between the two materials.

The most commonly used vertical heat exchange system is the borehole heat exchanger, which consists of one or two heat exchange tubes inserted into the vertical borehole and connected to the heat pump to form a closed loop. The space between the hole wall and the heat exchange tubes is grouted to enhance heat transfer between the soil and the circulating fluid. Vertically mounted heat exchangers still require a lot of land to drill, and the temperature remains basically constant at a certain depth underground. Vertical heat exchangers require less pipe length to produce the same efficiency as horizontal, but due to the higher Depth, and therefore higher installation costs, is a major obstacle to the application of ground source heat pump technology in urban areas.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a new type of ground source heat pump heat exchanger system and its application method which can use the anti-floating anchor rod holes as heat exchange holes, so as to improve the application of ground source heat pump technology in urban buildings.

The novel ground source heat pump heat exchanger system provided by the present invention includes a tubular heat exchanger, a heat exchange medium shunt pipe, a heat exchange medium return pipe, a water collector and a heat supply pipeline, and the tubular heat exchanger includes a lower end communicating with The spiral coil and vertical pipe are connected to the water collector, and the water collector is connected to the heat exchange medium shunt pipe and the heat exchange medium return pipe. Each tubular heat exchanger is embedded in the anti-floating bolt hole of the building. The upper end is communicated with the heat exchange medium shunt pipe, the upper end of the vertical pipe is communicated with the heat exchange medium return pipe, and the water collector and the radiator provide heating or heat dissipation to the building through the heat supply pipeline.

In an embodiment of the above system, both the spiral coil tube and the vertical tube are high-density polyethylene tubes.

In an embodiment of the above system, the upper ends of the spiral coil and the vertical pipe are respectively connected to 90° elbows of the high-density polyethylene pipe, and the 90° elbows are connected to the heat exchange medium shunt pipe and the heat exchange medium. Return line connection.

In an embodiment of the above system, a corresponding metal rigid waterproof casing is arranged outside the 90° elbow.

The method for burying the above-mentioned tubular heat exchanger in a building anti-floating anchor rod hole provided by the present invention includes the following steps:

(1) Weld the guide bracket at the designated position of the anchor rod and anchor bar;

(2) Binding and fixing the spiral coil of the tubular heat exchanger and the guide bracket, before fixing, adjust the height of the lower end of the tubular heat exchanger from the lower end of the anchor rod to be 150-250mm;

(3) Bind the two grouting pipes to the anchor rod and anchor bars respectively, the height of the lower end of one grouting pipe and the lower end of the anchor rod and anchor rod is 450-550mm, and the lower end of the other grouting pipe is 450-550mm away from the anchor rod and anchor rod. Lower end 2900-3100mm;

(4) The slag cleaning treatment of the bolt hole;

(5) Hang the integral piece fixed in steps (1)-(3) into the bolt hole;

(6) Pump clean water into the bolt hole to return water to the orifice;

(7) The anchor rod and the tubular heat exchanger are anchored in the anchor rod hole by the secondary grouting method;

(8) Connect each tubular heat exchanger with the heat exchange medium shunt pipe and the heat exchange medium return pipe.

6 . The method of claim 5 , wherein there are two anchor bars, which are welded and fixed to form an anchor body. 7 .

7. The method according to claim 5, wherein at least two groups of guide brackets are welded on the anchor rod and anchor bars, each group includes a plurality of guide brackets, and each guide bracket includes a long vertical section and its Symmetrical inner bending sections at both ends and short vertical sections folded outwards at the ends of the inner bending sections are welded and fixed to different orientations of the anchor rod and anchor bars.

8. The method according to claim 5, characterized in that: the first grouting pressure is 0.4-0.5MPa, and the second grouting is performed 2 hours after the first grouting is completed, and the second grouting pressure is The pressure is 2-3MPa.

In the invention, the anti-floating anchor rod hole is used for the installation of the ground source heat pump tubular heat exchanger, and the anchor rod is used as a heat exchange hole on the basis of the anti-floating measure of the traditional underground structure, so as to realize the construction of the anti-floating anchor rod and the prefabrication of the ground source heat pump. The construction of the hole-buried spiral tubular heat exchanger is integrated and completed at one time. The ground source heat pump tubular heat exchanger arranged in the anti-floating anchor rod hole adopts a spiral tube with excellent heat exchange performance, combined with the characteristics of the small distance between the anti-floating anchor rod holes, it can not only play the role of the independent drilling and buried tubular heat exchanger. It has the same effect as the heater, and saves the cost and construction period of the independent drilling and buried pipe construction of the ground source heat pump. The temperature effect produced by the heat exchange is within the working range of the steel bar and cement mortar, and the influence on the load performance of the bolt is within the controllable range. The helical tubular heat exchangers arranged in the anti-floating bolt holes are bound on the inner side of the guide bracket. Compared with the independent drilling and buried pipes, the positional accuracy of the buried pipes of the tubular heat exchangers can be effectively guaranteed. The invention belongs to a closed ground source heat pump exchange system. Compared with an open system, the invention does not need to rely on abundant groundwater resources and consumes extra electricity due to pumping, and also avoids frequent pumping cycles and pipeline corrosion, scaling, bacteria and pollution. It will cause ecosystem damage and waste of groundwater resources. In addition, anti-floating anchor rods are widely used in China. The promotion and use of this technology will further promote the development of ground source heat pump technology, especially to improve the application of ground source heat pump technology in urban buildings. The environment and economic benefits are extremely significant. .

Description of drawings

FIG. 1 is a schematic diagram of a system structure in an embodiment of the present invention.

FIG. 2 is an enlarged schematic diagram of part A in FIG. 1 .

FIG. 3 is an enlarged schematic diagram of part B in FIG. 1 .

FIG. 4 is an enlarged schematic diagram of part C in FIG. 1 .

Detailed ways

In order to solve the problems of high cost of traditional ground source heat pump drilling and backfilling materials and occupy additional land, and to promote the popularization and application of ground source heat pump technology, the invention utilizes the characteristics of a large number of bolt holes and a hole depth of about 10 meters. The anti-floating bolt hole is used for the burying and installation of the ground source heat pump tubular heat exchanger to realize the integration of the anti-floating bolt construction and the construction of the ground source heat pump prefabricated hole buried tubular heat exchanger, and the bolt is used as a traditional underground heat exchanger. In addition to the anti-floating measures of the structure, the anchor hole is used as a heat exchange hole to exchange heat between the building and the soil layer. The temperature of the former changes with different seasons, and the latter is the source of constant temperature throughout the year.

However, the diameter of the bolt hole is small, so in order to adapt to the installation of the bolt hole, a new tubular heat exchanger needs to be designed.

The new tubular heat exchanger in this embodiment includes spiral coils 1 and vertical tubes 2 arranged in parallel, and their lower ends communicate with each other. The upper end of the straight pipe 2 flows out and returns to the heat exchange medium return pipe of the water collector, and then returns to the water collector to divide and circulate for heat exchange. When the temperature of the heat exchange medium in the water collector reaches the set requirements, the pump will be used in the building. Specifically, in summer, the heat in the building flows through the heat exchange medium in the pipeline and the spiral coil in the anti-floating anchor hole and exchanges heat with the soil layer to reduce the temperature and return to refrigeration. In winter, the heat exchange medium flows in the spiral coil in the bolt hole and the heat exchange temperature of the soil layer increases, and then it is sent to the building for heating.

The water collector can be installed in the outdoor inspection well 8, and the water pump can be installed in the refrigerating machine room in the basement.

The long stroke of the heat exchange medium flowing through the spiral coil 1 can prolong the heat exchange time between the heat exchange medium and the outer soil layer of the bolt hole 3 and improve the heat exchange efficiency. In addition, the longer stroke and larger heat exchange area of the spiral coil 1 can be achieved by adjusting the spacing between the coil coils, that is, the spiral coil is used as a heat exchange tube, which has greater heat transfer compared with the straight tube area and better flow patterns. When the spiral coil 1 and the vertical pipe 2 are connected in series, there will be no air blockage in the pipe at the bend, and the gas can also be placed at the top of the pipe to collect. Therefore, the tubular heat exchanger structure of this embodiment is an ideal choice when the land is limited and the building occupies a large area.

The spiral coil 1 and the vertical pipe 2 are made of high-density polyethylene material, which is more convenient for grouting and anchoring in the bolt hole 3 .

After the tubular heat exchanger and the anchor rod are fixed as a whole, they are hoisted into the anchor rod by lifting equipment such as a tower crane or a truck crane and buried.

The anchor rod is made of two anchor bars 4 welded by steel bars 5 . The total length of the anchor rod is determined according to the hole depth of the anchor rod hole and the required length in the basement floor.

In this embodiment, a set of guide brackets 6 are welded to the bottom and the upper part of the outer wall of the anchor rib 4 respectively, and the anchor rod is ensured to be located at the axial center of the anchor rod hole through the guide brackets.

The guide bracket 6 includes a long vertical section, an inner folded section symmetrical at both ends thereof, and a short vertical section at the outer end of the inner folded section.

When the guide bracket 6 is fixed with the anchor rib 4, the short vertical sections at both ends are welded to the outer wall of the anchor rib.

The spiral coil 1 of the tubular heat exchanger is set between the anchor rod and the area enclosed by the vertical section of the guide bracket 6, so before the guide bracket 6 and the anchor rib 4 are welded, first set the spiral coil 1 Outside the anchor bar 4, the guide bracket 6 and the anchor bar are welded and fixed, and the spiral coil 1 is bound and fixed. Note that the lower end surface of the spiral coil tube 1 is about 150mm above the lower end surface of the anchor rod.

Next, the grouting pipe and the anchor bars 4 are tied and fixed (not shown in the figure). The grouting pipe is set with two primary grouting pipes and secondary grouting pipes, both of which use plastic pipes with an inner diameter of 20 mm. The lower end face of the primary grouting pipe is about 500mm above the lower end face of the bolt, and the lower end face of the secondary grouting pipe is about 3000mm above the lower end face of the bolt.

So far, the anchor rod, the guide bracket, the spiral coil and the grouting pipe form a whole piece that can be hoisted, and check the straightness of the anchor bar and whether the grouting pipe is broken or blocked.

The construction steps for burying the integral part in the bolt hole are as follows:

(1) Blow out the residue in the bolt hole with high pressure air until the thickness of the sediment in the hole is less than 20mm. If necessary, carry out secondary hole cleaning to clean up the sediment and accumulated water in the hole;

(2) Use tower cranes, truck cranes and other hoisting equipment to hoist the whole piece into the bolt hole. If the bolt cannot be lowered to the bottom of the hole, lift the whole piece out and use a drilling rig to sweep the hole again before lowering the anchor;

(3) Pump clean water to the orifice to return water;

(4) For the first grouting, the grouting pressure is 0.4-0.5MPa. Gradually lift the first grouting pipe with the cement mortar injection, and ensure that the grouting pipe mouth is always located at a position not less than 1000mm below the grout surface until grouting Finish. The grouting must be carried out continuously until the grout out of the orifice is cement mortar and then light grouting;

(5) The second grouting starts after the initial setting strength of the first grouting reaches 5MPa (2 hours after the completion of the first grouting), and the grouting pressure is 2-3MPa. The secondary grouting pipe injects the cement slurry into the bottom of the hole, the cement mortar is filled in sequence from the bottom of the hole and the air in the hole is pressed out, while the cement mortar is squeezed out from the hole and breaks through the first grouting body. After the secondary grouting, before the strength of the slurry does not meet the design requirements, the bolt body and the heat exchanger of the ground source heat pump shall not bear the external force or the movement of the anchor body caused by the external force.

After the anchor rod and the tubular heat exchanger are poured into each anchor rod hole, 90° elbows of the same material are respectively connected to the upper ends of each helical coil 1 and vertical tube 2, and 90° metal elbows are coated on the 90° elbows. Elbow, connect the plastic elbow on the upper end of each spiral coil pipe to the heat exchange medium shunt pipe respectively, and connect the plastic elbow on the upper end of each vertical pipe to the heat exchange medium return pipe to form a loop.

Check that the pressure of the circuit and the water collector as a whole has no leakage, and ensure that the water pressure of each pipeline is qualified to complete the construction.

Of course, according to the actual needs, considering the actual heat load of the building and the need to control the cost of the ground source heat pump system, the ground source heat pump tubular heat exchanger can be designed to be buried in all the anti-floating anchor holes or buried at intervals.

It can be seen from the tubular heat exchanger structure of the present embodiment and its casting process in the bolt hole that the present invention has the following advantages:

The anti-floating anchor rod hole is used for the installation of the tubular heat exchanger of the ground source heat pump. The anchor rod is used as a heat exchange hole on the basis of the anti-floating measure of the traditional underground structure, so as to realize the anti-floating anchor rod construction and the ground source heat pump prefabricated hole buried screw. The construction of the linear tubular heat exchanger is integrated and completed at one time. The ground source heat pump tubular heat exchanger arranged in the anti-floating anchor rod hole adopts a spiral tube with excellent heat exchange performance, combined with the characteristics of the small distance between the anti-floating anchor rod holes, it can not only play the role of the independent drilling and buried tubular heat exchanger. It has the same effect as the heater, and saves the cost and construction period of the independent drilling and buried pipe construction of the ground source heat pump. The temperature effect produced by the heat exchange is within the working range of the steel bar and cement mortar, and the influence on the load performance of the bolt is within the controllable range. The helical tubular heat exchangers arranged in the anti-floating bolt holes are bound on the inner side of the guide bracket. Compared with the independent drilling and buried pipes, the positional accuracy of the buried pipes of the tubular heat exchangers can be effectively guaranteed.

The above technology belongs to the closed ground source heat pump exchange system. Compared with the open system, it does not need to rely on abundant groundwater resources and consumes extra electricity due to pumping, and also avoids frequent pumping cycles and pipeline corrosion, scaling, bacteria, and pollution. It will cause ecosystem damage and waste of groundwater resources. In addition, anti-floating anchor rods are widely used in China. If this technology can be widely used, it will further promote the development of ground source heat pump technology, and the environmental and economic benefits are extremely significant.

Claims (8)

1. a novel ground source heat pump heat exchanger system is characterized in that: the system comprises a tubular heat exchanger, a heat exchange medium shunt pipe, a heat exchange medium return pipe, a water collector and a heat supply pipeline, and the tubular heat exchange The heat exchanger includes a spiral coil tube and a vertical tube connected at the lower end. The water collector is connected to the heat exchange medium shunt pipe and the heat exchange medium return pipe. Each tubular heat exchanger is embedded in the anti-floating anchor rod hole of the building. The upper end of the spiral coil pipe is communicated with the heat exchange medium shunt pipe, the upper end of the vertical pipe is communicated with the heat exchange medium return pipe, and the water collector provides heating or heat dissipation to the building through the heating pipeline. 2 . The novel ground source heat pump heat exchanger system according to claim 1 , wherein the spiral coil tube and the vertical tube are made of high-density polyethylene tubes. 3 . 3. The novel ground source heat pump heat exchanger system according to claim 2, wherein the upper ends of the spiral coil and the vertical pipe are respectively connected to the 90° elbow of the high-density polyethylene pipe, and the 90° elbow The head is connected to the heat exchange medium branch pipe and the heat exchange medium return pipe. 4 . The novel ground source heat pump heat exchanger system according to claim 3 , wherein a corresponding metal rigid waterproof casing is arranged outside the 90° elbow. 5 . 5. a method for burying tubular heat exchanger in building anti-floating anchor rod hole in claim 1, comprising the following steps: (1) Weld the guide bracket at the designated position of the anchor rod and anchor bar; (2) Binding and fixing the spiral coil of the tubular heat exchanger and the guide bracket, before fixing, adjust the height of the lower end of the tubular heat exchanger from the lower end of the anchor rod to be 150-250mm; (3) Bind the two grouting pipes to the anchor rod and anchor bars respectively, the height of the lower end of one grouting pipe and the lower end of the anchor rod and anchor rod is 450-550mm, and the lower end of the other grouting pipe is 450-550mm away from the anchor rod and anchor rod. Lower end 2900-3100mm; (4) The slag cleaning treatment of the bolt hole; (5) Hang the integral piece fixed in steps (1)-(3) into the bolt hole; (6) Pump clean water into the bolt hole to return water to the orifice; (7) The anchor rod and the tubular heat exchanger are anchored in the anchor rod hole by the secondary grouting method; (8) Connect each tubular heat exchanger with the heat exchange medium shunt pipe and the heat exchange medium return pipe. 6 . The method according to claim 5 , wherein there are two anchor bars, which are welded and fixed to form an anchor body. 7 . 7 . The method according to claim 5 , wherein at least two groups of guide brackets are welded on the anchor rod and anchor bars, and each group includes a plurality of guide brackets, and each guide bracket includes a long vertical section and its middle guide bracket. 8 . Symmetrical inner bending sections at both ends and short vertical sections folded outwards at the ends of the inner bending sections are welded and fixed to different orientations of the anchor rod and anchor bars. 8. The method of claim 5, wherein the first grouting pressure is 0.4-0.5MPa, and the second grouting is carried out 2 hours after the first grouting is completed, and the second grouting pressure The pressure is 2-3MPa.

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