Underground water source heat pump recharge well bottom sand cleaning device

Abstract

The utility model relates to the field of shallow geothermal energy clean energy, in particular to an underground water source heat pump recharge well bottom sand cleaning device. The device comprises a well pipe, a water pumping pipe, a recharge pipe, a water inlet pipe and a pumped water treatment device, the well pipe is inserted into a geothermal recharge well, and the water inlet pipe is used for injecting clear water into the bottom of the geothermal recharge well; the water pumping pipe and the recharge pipe are arranged in the well pipe, one side of the well bottom of the water pumping pipe is connected with a lift water pump, the other side of the well bottom of the water pumping pipe is connected with a water inlet of the lift water treatment equipment, a water outlet of the lift water treatment equipment is connected with the recharge pipe, and lift water enters the lift water treatment equipment through the lift water pump and the water pumping pipe. And after being filtered, the water is injected into the geothermal recharge well through the recharge pipe. The device does not need transportation equipment and can be continuously utilized after being put into one time; the sand cleaning frequency and the sand cleaning time can be set through the controller, a sand well non-cleaning strategy can be adopted for different stratums, sand cleaning can be conducted at any time, the applicability is wide, and the method is not limited by the well depth and the well diameter.

Description

Technical Field

[0001] The utility model relates to the technical field of shallow geothermal clean energy, in particular to a bottom sand cleaning device for a groundwater source heat pump recharging well. Background Art

[0002] The groundwater source heat pump system is a heat extraction device frequently used in the field of building heating. It uses a submersible pump to extract groundwater from a pumping well, exchanges heat energy in the groundwater through a heat pump unit, and then recharges the geothermal groundwater into the recharge well. However, for many current projects, a common problem is that the silt in the stratum will flow into the recharge well with the water flow and settle at the bottom of the well. The long-term accumulation of silt and sediment will cause the well depth to become shallower, and even cause part of the aquifer at the bottom of the well to be blocked, affecting the recharge effect and further affecting the building heating area. How to better deal with the siltation in the well and reduce the risk of developing and utilizing groundwater source heat pumps is an important issue of common concern to the majority of hydrogeological workers.

[0003] At present, for users of groundwater source heat pumps, the main way to solve this problem is to use sand bailing equipment or air compressors for regular cleaning, but the above methods all require the equipment to be transported to the site and cleaned; some users are not aware of sand removal from the bottom of the well, or due to cost issues, the cleaning is not timely, thorough, or the cycle is too long, which still cannot completely solve the problem. Some projects even implement heat exchange wells in the basement of buildings, making it inconvenient to use equipment such as well washing. Utility Model Content

[0004] The purpose of the utility model is to overcome the defects of the existing technology and propose a groundwater source heat pump recharge well bottom sand cleaning device, which can be implemented simultaneously with the construction of the groundwater source heat pump geothermal well to solve the problem of weakened recharge capacity of the geothermal recharge well due to siltation at the bottom of the recharge well after the construction of the existing groundwater source heat pump project. The utility model is particularly suitable for use in areas where the groundwater aquifer contains fine sand or silt sand.

[0005] In order to achieve the above purpose, the utility model adopts the following specific technical solutions:

[0006] The utility model provides a sand-cleaning device for the bottom of a groundwater source heat pump recharging well, comprising a well pipe, a water pumping pipe, a recharging pipe, a water inlet pipe and a recharging water treatment device. The well pipe is inserted into a geothermal recharging well; the water inlet pipe is arranged between the outside of the well pipe and the wall of the geothermal recharging well, the bottom of the water inlet pipe is bent toward the well pipe and enters the bottom of the well pipe, and the water inlet pipe is used to inject clean water into the bottom of the geothermal recharging well;

[0007] The pumping pipe and the reinjection pipe are arranged in the well pipe. A return water pump is connected to one side of the pumping pipe at the bottom of the well, and the other side of the pumping pipe is connected to the water inlet of the return water treatment equipment. The water outlet of the return water treatment equipment is connected to the reinjection pipe, so that the return water enters the return water treatment equipment through the return water pump and the pumping pipe, and is then injected into the geothermal reinjection well through the reinjection pipe after filtration.

[0008] Preferably, a high-pressure water pump connected to a clean water pipe is provided at the top of the water inlet pipe for injecting clean water into the bottom of the geothermal recharge well through the water inlet pipe.

[0009] Preferably, a contraction-conical nozzle is provided at the bottom of the water inlet pipe for ejecting high-pressure clean water to disturb the sand deposited at the bottom of the well.

[0010] Preferably, gravel is filled between the well pipe and the geothermal recharge well wall and the water inlet pipe as a permeable layer, and a water-stopping material is provided on the top of the gravel. The water-stopping material can be clay balls or cement.

[0011] Preferably, an electric control valve is provided at the water outlet of the return water treatment equipment to control the opening and closing of the water outlet.

[0012] The utility model can achieve the following technical effects:

[0013] 1. The sand cleaning device for the bottom of the groundwater source heat pump recharging well provided by the utility model is implemented simultaneously with the project construction. Compared with the ordinary sand cleaning method, it does not need to transport the equipment to the site, nor does it need to invest manpower. It can be invested once and used sustainably, which greatly reduces the cost;

[0014] 2. The device is easy to use. The sand cleaning frequency and duration can be set through the controller. For different formations, a sand cleaning strategy can be adopted to clean sand at any time;

[0015] 3. This device is highly flexible and widely applicable. It is not limited by the depth and diameter of the well. It also solves the problem that the geothermal reinjection well is located in a place where sand cleaning equipment is inconvenient to enter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The utility model is a schematic structural diagram of a bottom sand cleaning device for a groundwater source heat pump recharging well provided in accordance with an embodiment of the utility model.

[0017] Reference numerals include:

[0018] Electric control valve 1, return water treatment equipment 2, water pumping pipe 3, reinjection pipe 4, first controller 501, second controller 502, high-pressure water pump 6, water-stop material 7, gravel 8, well pipe 9, return water pump 10, water inlet pipe 11, sub-sand 12, gravel 13, mudstone 14, geothermal reinjection well 15, clean water pipe 16, and contraction conical nozzle 17. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present utility model will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0020] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and do not constitute a limitation of the utility model.

[0021] The utility model provides a sand cleaning device for the bottom of a groundwater source heat pump recharging well, the structure of which is as follows Figure 1 As shown. The bottom sand cleaning device of the groundwater source heat pump recharging well mainly includes a well pipe 9, a pumping pipe 3, a recharging pipe 4, a water inlet pipe 11 and a return water treatment device 2. The well pipe 9 is inserted into the geothermal recharging well 15; the water inlet pipe 11 is arranged between the outer side of the well pipe 9 and the well wall of the geothermal recharging well 15, the bottom of the water inlet pipe 11 is bent toward the well pipe 9 and enters the bottom of the well pipe 9, and a high-pressure water pump 6 connected to the clean water pipe 16 is arranged on the top of the water inlet pipe 11. The high-pressure water pump 6 is controlled to start and stop by the second controller 502, and is used to inject clean water into the bottom of the geothermal recharging well 15 through the water inlet pipe 11.

[0022] The pumping pipe 3 and the recharging pipe 4 are arranged in the well pipe 9. A recharging pump 10 is connected to one side of the well bottom of the pumping pipe 3. The recharging pump 10 controls the start and stop and the recharging flow rate through the first controller 501. The other side of the pumping pipe 3 is connected to the water inlet of the recharging water treatment equipment 2. The water outlet of the recharging water treatment equipment 2 is connected to the recharging pipe 4. The recharging water enters the recharging water treatment equipment 2 through the recharging pump 10 and the pumping pipe 3, and is then injected into the geothermal recharging well 15 through the recharging pipe 4 after filtration.

[0023] In a preferred embodiment, a contraction-type conical nozzle 17 is provided at the bottom of the water inlet pipe 11 for ejecting high-pressure clean water to disturb the sand deposited at the bottom of the well. An electric control valve 1 is provided at the outlet of the return water treatment device 2 for controlling the opening and closing of the outlet.

[0024] The bottom sand cleaning device of the groundwater source heat pump recharging well provided by the utility model is described below in conjunction with specific embodiments.

[0025] The geothermal recharge well has a hole diameter of 650mm, a well diameter of 300mm, and a well depth of 80m. The well pipe 9 is a cement pipe. The well body penetrates from the surface through the sub-sand 12, gravel 13, and mudstone 14 strata, and the diameter does not change in the middle. The sub-sand 12 and gravel 13 are the covering layers with loose structures. The gravel 13 is the aquifer, and the lower mudstone 14 is the waterproof bottom plate. The well pipe 9 is lowered, and gravel 8 is filled between the well wall and the well pipe wall as a permeable layer, and the top is sealed with water-stopping material 7.

[0026] A return water pump 10 connected to the first controller 501 is lowered into the geothermal recharge well 15. The depth of the return water pump 10 is less than 3m of the depth of the geothermal recharge well 15. The first controller 501 can control the start and stop of the return water pump 10 and the return flow rate. The return water pump 10 is connected to the pumping pipe 3, and the pumping pipe 3 is connected to the water inlet of the return water treatment equipment 2. The return water enters the return water treatment equipment 2 through the pumping pipe 3. The return water treatment equipment 2 can filter the sand in the return water and clean it regularly. The outlet of the return water treatment equipment 2 is provided with an electric control valve 1, which can control the opening and closing of the outlet. The return pipe 4 is lowered below the water level of the geothermal recharge well 15, and one end is connected to the outlet of the return water treatment equipment 2 through a tee at the wellhead, and the other end is connected to the main pipeline of the return pipe 4. A water inlet pipe 11 is inserted between the well pipe 9 and the well wall of the geothermal recharge well 15. The water inlet pipe 11 is made of φ110 polyethylene pipe (PE pipe), and the length of a single pipe is 6m. The connection method is electric fusion connection. The water inlet pipe 11 is connected to the high-pressure water pump 6 with a second controller 502 on the ground. The second controller 502 mainly controls the start and stop of the compressor of the high-pressure water pump 6. The high-pressure water pump 6 is connected to the clean water pipe 16. The bottom of the water inlet pipe 11 is bent 90 degrees toward the well pipe 9 at the bottom of the well and enters the well pipe 9. The part entering the well pipe 9 is provided with a plurality of upward contraction conical nozzles 17. The high-pressure water pump 6 injects clean water into the bottom of the well through the water inlet pipe 11, and sprays high-pressure water through the contraction conical nozzle 17 to disturb the sand deposited at the bottom of the well. Gravel 8 is filled between the well pipe 9 and the well wall of the geothermal reinjection well 15 and outside the water inlet pipe 11. The gravel 8 is mainly river stone. A water-stopping material 7 is arranged on the top of the gravel 8. The water-stopping material 7 can be selected from clay balls and cement.

[0027] The working mode of the bottom sand cleaning device of the groundwater source heat pump recharging well provided in this embodiment is as follows:

[0028] First, open the electric control valve 1 at the outlet of the return water treatment equipment 2, and start the high-pressure water pump 6 and the return water pump 10. The high-pressure water pump 6 injects the clean water in the clean water pipe 16 into the bottom of the geothermal reinjection well 15 through the water inlet pipe 11. The high-pressure clean water is ejected through the contraction conical nozzle 17 and disturbs the sand deposited at the bottom of the well, so that the mud and sand originally deposited at the bottom of the well are driven into the well; the return water pump 10 transports the mud and sand to the return water treatment equipment 2 through the pumping pipe 3 by pumping water, and the filtered water is injected into the geothermal reinjection well 15 through the reinjection pipe 4. After cleaning, turn off the high-pressure water pump 6 and the return water pump 10.

[0029] The above process is a sand cleaning process. The working hours and working frequencies of the first controller 501 and the second controller 502 are set according to the geological conditions of the project area. Generally, they can be turned on once a week, and the working time is 24 hours.

[0030] The above process can be used during the heating period of the groundwater source heat pump system without affecting the normal heating. The return pump 10 can be manually lifted to remove the sediment at the bottom of the well and also realize the return function of the groundwater corresponding to the aquifer.

[0031] The sand cleaning device for the bottom of the groundwater source heat pump recharging well provided in this embodiment is implemented simultaneously with the project construction. Compared with the ordinary sand cleaning method, it does not need to transport the equipment to the site, nor does it need to invest manpower, which greatly reduces the cost and solves the problem that some geothermal recharging wells cannot be accessed by well cleaning equipment due to limited site. At the same time, the utility model can be started and stopped at any time and cleaned at any time through the controller, which does not affect the normal use of the groundwater source heat pump, and can also clean the mud and sand at the bottom of the well at any time during the heating period. It is particularly suitable for use in areas where the groundwater aquifer contains fine sand or silt sand.

[0032] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0033] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

[0034] The above specific implementation methods of the utility model do not constitute a limitation on the protection scope of the utility model. Any other corresponding changes and modifications made according to the technical concept of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. A sand cleaning device for the bottom of a groundwater source heat pump recharging well, characterized in that: It includes a well pipe, a pumping pipe, a recharging pipe, a water inlet pipe and a recharging water treatment device. The well pipe is inserted into a geothermal recharging well. The water inlet pipe is arranged between the outside of the well pipe and the wall of the geothermal recharging well. The bottom of the water inlet pipe is bent toward the well pipe and enters the bottom of the well pipe. The water inlet pipe is used to inject clean water into the bottom of the geothermal recharging well. The water pumping pipe and the reinjection pipe are arranged in the well pipe, and a reinjection water pump is connected to one side of the well bottom of the water pumping pipe, and the other side of the water pumping pipe is connected to the water inlet of the reinjection water treatment equipment, and the water outlet of the reinjection water treatment equipment is connected to the reinjection pipe, so that the reinjection water enters the reinjection water treatment equipment through the reinjection water pump and the water pumping pipe, and is then injected into the geothermal reinjection well through the reinjection pipe after filtration.

2. The bottom sand cleaning device for groundwater source heat pump recharging well according to claim 1 is characterized in that: A high-pressure water pump connected to a clean water pipe is provided on the top of the water inlet pipe, and is used to inject clean water into the bottom of the geothermal recharge well through the water inlet pipe.

3. The bottom sand cleaning device for groundwater source heat pump recharging well according to claim 1 is characterized in that: A contraction-type conical nozzle is arranged at the bottom of the water inlet pipe, which is used to spray high-pressure clean water to disturb the sand deposited at the bottom of the well.

4. The bottom sand cleaning device for groundwater source heat pump recharging well according to claim 1, characterized in that: Gravel is filled between the well pipe, the geothermal recharge well wall and the water inlet pipe as a permeable layer, and a water-stopping material is arranged on the top of the gravel. The water-stopping material can be clay balls or cement.

5. The bottom sand cleaning device for groundwater source heat pump recharging well according to claim 1, characterized in that: An electric control valve is arranged at the water outlet of the return water treatment equipment to control the opening and closing of the water outlet.

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