Phase change energy pile suitable for soft soil layer

Abstract

The utility model discloses a phase change energy pile suitable for a soft soil layer, which belongs to the field of ground source heat pump technology and energy underground structures, and comprises a trapezoidal pile body, a spiral water inlet pipe, a water return pipe, a phase change material, a connecting pipe and a support rod, the two spiral water inlet pipes are respectively wrapped by the winter and summer two-season wrapping type phase change material; the two spiral water inlet pipes and the two spiral water return pipes are arranged in a cavity of the trapezoid pile body in a regular triangle shape and fixed through the supporting rods, and then the cavity of the pile body is filled with backfill soil for sealing. Friction resistance between the pile body and soft soil is increased through the trapezoid protrusions of the pile body, sedimentation is reduced through the supporting plate at the bottom of the pile body, the sedimentation problem of the pile body on the soft soil layer is solved, and heat exchange between the pile body and the soil body can be enhanced. In addition, by means of phase change of the phase change material, the problems of heat deformation amplitude of the pile body caused by heat exchange and heat short circuit between the water inlet pipe and the water return pipe are relieved, and energy storage and heat exchange performance is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to ground source heat pump technology and energy underground structure technical field, concretely is a kind of phase change energy pile suitable for soft soil layer. BACKGROUND

[0002] The main function of traditional building pile foundation is to support the weight of the building, while the energy pile is an innovative design that combines traditional ground heat exchanger with building pile foundation. While the pile foundation bears the load of the building, the energy pile uses the available space inside the pile foundation to install the heat exchanger. In this way, the energy pile can effectively extract cold and heat energy from the underground soil to provide cooling and heating supply for the building. This design not only reduces the cost of drilling separate ground pipes, but also effectively solves the problem of large space occupation of traditional buried pipe heat exchanger, thereby bringing significant economic benefits.

[0003] During the operation of the energy pile, temperature changes can cause thermal expansion and contraction, leading to a series of mechanical problems. These problems can threaten the structural stability of the energy pile, especially in special soil conditions such as soft soil or desert areas, where the bearing capacity of the pile foundation is more challenging. In these areas, the frictional resistance between the pile foundation and the soil and the supporting force at the bottom are relatively weak, which can easily cause the pile foundation to sink. In addition, the thermal expansion and contraction caused by the heat exchange process of the energy pile can further exacerbate the sinking problem of the pile foundation, thereby reducing its bearing capacity and increasing the engineering risk. At the same time, as a device that both bears load and exchanges heat, the water inlet pipe and water return pipe of the buried heat exchanger inside the energy pile are usually placed in a limited space, which can cause thermal interference between the water inlet pipe and water return pipe.

[0004] Therefore, it is necessary to develop a new type of phase change energy pile specifically for soft soil layers. The design of this new type of energy pile needs to ensure the stability of the pile foundation in soft soil layers while improving the heat exchange efficiency between the pile body and the surrounding soil. In addition, it should also effectively solve the problem of thermal short circuit in traditional buried pipe heat exchangers. Through such design, the new type of energy pile can better perform its functions in soft soil layers, improving the overall engineering performance and reliability. SUMMARY

[0005] To overcome the shortcomings of the prior art, the utility model discloses a kind of phase change energy piles suitable for soft soil layer, to improve the sinking problem of pile foundation caused by thermal expansion and contraction during the operation of energy pile under soft soil condition;At the same time, this new type of phase change energy pile can improve the heat exchange between the pile body and the soil, and can alleviate the thermal interference phenomenon;In addition, the phase change of phase change material is used to alleviate the thermal deformation amplitude of the pile body caused by heat exchange and the thermal short circuit problem between water inlet pipe and water return pipe, and increase the energy storage and heat exchange performance.

[0006] In order to achieve the above object, the utility model provides the following technical scheme: a kind of phase change energy pile suitable for soft soil layer, including trapezoidal pile body, first spiral water inlet pipe, second spiral water inlet pipe, return pipe, three-way and connecting pipe;

[0007] The trapezoidal pile body is internally provided with a first spiral water inlet pipe, a second spiral water inlet pipe and a return pipe, the inlet of the first spiral water inlet pipe and the second spiral water inlet pipe is connected with the outlet of a condenser or an evaporator in a heat pump system, and the first spiral water inlet pipe, the second spiral water inlet pipe and the total water inlet pipe are connected with the three-way provided; the outlet of the return pipe is connected with the inlet of the condenser or the evaporator in the heat pump system; the connecting pipe is placed at the bottom of the trapezoidal pile body, and the first spiral water inlet pipe, the second spiral water inlet pipe and the return pipe are connected through the connecting pipe.

[0008] Preferably, the outer wall of the trapezoidal pile body comprises a straight pipe segment and a trapezoidal protruding pipe segment in sequence, the lower end of the trapezoidal pile body is provided with a support plate, the trapezoidal pile body is internally provided with an internal cavity, the trapezoidal pile body is embedded in the soil body, and the internal cavity is filled with backfill soil.

[0009] Preferably, the outer layer of the first spiral water inlet pipe is wrapped with summer phase change material, the outer layer of the second spiral water inlet pipe is wrapped with winter phase change material; the first spiral water inlet pipe, the second spiral water inlet pipe and the return pipe are embedded in the internal cavity in the form of an equilateral triangle; the lower end of the first spiral water inlet pipe, the second spiral water inlet pipe and the return pipe is connected with the connecting pipe at the bottom.

[0010] Preferably, the first valve and the second valve are respectively installed on the first spiral water inlet pipe and the second spiral water inlet pipe.

[0011] Preferably, in summer working condition, the first valve is kept open, and the second valve is kept closed; in winter working condition, the first valve is kept closed, and the second valve is kept open.

[0012] Preferably, the first spiral water inlet pipe, the second spiral water inlet pipe and the return pipe are fixed by the support rods provided therebetween, and one support rod is installed every 3 meters in the depth direction.

[0013] Preferably, the trapezoidal pile body is made of steel fiber reinforced concrete pile body, the first spiral water inlet pipe, the second spiral water inlet pipe and the return pipe are made of PE pipe, and the three-way and the connecting pipe are made of PE material.

[0014] Compared with the prior art, the utility model has the beneficial effects that:

[0015] 1. The trapezoidal pile body protruding pipe section design can not only enhance the heat exchange efficiency between the pile body and the soil, but also enhance the friction resistance between the pile body and the soil, thereby relieving the sinking problem of the pile body in the soft soil layer caused by thermal expansion and contraction during operation, improving the energy efficiency of the ground source heat pump system, and having important significance and wide application prospect.

[0016] 2. The trapezoidal pile body bottom provided with the support plate can effectively relieve the sinking problem of the pile body caused by thermal expansion and contraction during operation.

[0017] 3. The support rod is arranged to fix the spiral water inlet pipe and the return pipe, so that the heat short circuit problem between the inlet pipe and the return pipe can be relieved.

[0018] 4. The spiral water inlet pipe is arranged to increase the heat exchange area, thereby improving the heat exchange performance.

[0019] 5. The phase change material is wrapped outside the heat exchange pipe to relieve the heat deformation amplitude of the pile body and the heat short circuit problem between the inlet pipe and the return pipe, and to increase the energy storage and heat exchange performance of the pile body. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, and are used to explain the present application together with embodiments of the present application, and do not constitute a limitation of the present application.

[0021] In the drawings:

[0022] Figure 1 is a structure schematic view of a phase change energy pile suitable for soft soil layer of the present application;

[0023] Figure 2 is a structure schematic view in the internal cavity of the trapezoidal pile body of the present application;

[0024] Reference numerals in the drawings: 1-1, straight pipe section; 1-2, trapezoidal protruding pipe section; 1-3, support plate; 1-4, internal cavity; 2-1, first spiral water inlet pipe; 2-2, second spiral water inlet pipe; 3, return pipe; 4-1, summer phase change material; 4-2, winter phase change material; 5-1, first valve; 5-2, second valve; 6, tee joint; 7, connecting pipe; 8, support rod; 9, backfill soil. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present application are described below in conjunction with the drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and do not limit the present application.

[0026] Embodiment: As shown in Figure 1 and Figure 2 A phase change energy pile suitable for soft soil layer, comprising a trapezoidal pile body, a first spiral water inlet pipe 2-1, a second spiral water inlet pipe 2-2, a water return pipe 3, a tee joint 6 and a connecting pipe 7.

[0027] The outer wall of the trapezoidal pile body comprises a straight pipe section 1-1 and a trapezoidal protruding pipe section 1-2 in sequence, the lower end of the trapezoidal pile body is provided with a support plate 1-3, the inside of the trapezoidal pile body is provided with an internal cavity 1-4, the trapezoidal pile body is embedded in the soil body, the internal cavity 1-4 is filled with backfill soil 9, the inside of the trapezoidal pile body is provided with the first spiral water inlet pipe 2-1, the second spiral water inlet pipe 2-2 and the water return pipe 3, the first spiral water inlet pipe 2-1, the second spiral water inlet pipe 2-2 and the water return pipe 3 are embedded in the internal cavity 1-4 in an equilateral triangle shape, the first spiral water inlet pipe 2-1, the second spiral water inlet pipe 2-2 and the water return pipe 3 are fixed by the support rods 8 provided therebetween, and one support rod 8 is installed every 3 meters in the depth direction, the outer layer of the first spiral water inlet pipe 2-1 is wrapped with summer phase change material 4-1, and the outer layer of the second spiral water inlet pipe 2-2 is wrapped with winter phase change material 4-2; the lower ends of the first spiral water inlet pipe 2-1, the second spiral water inlet pipe 2-2 and the water return pipe 3 are connected with the connecting pipe 7 at the bottom; the inlets of the first spiral water inlet pipe 2-1 and the second spiral water inlet pipe 2-2 are connected with the outlet of the condenser or the evaporator in the heat pump system, and the first spiral water inlet pipe 2-1, the second spiral water inlet pipe 2-2 and the total water inlet pipe are connected with the tee joint 6 provided there; the outlet of the water return pipe 3 is connected with the inlet of the condenser or the evaporator in the heat pump system; the connecting pipe 7 is arranged at the bottom of the trapezoidal pile body, and the first spiral water inlet pipe 2-1, the second spiral water inlet pipe 2-2 and the water return pipe 3 are connected through the connecting pipe 7.

[0028] Further, the first valve 5-1 and the second valve 5-2 are respectively installed on the first spiral water inlet pipe 2-1 and the second spiral water inlet pipe 2-2; in summer working condition, the first valve 5-1 is kept open, and the second valve 5-2 is kept closed; in winter working condition, the first valve 5-1 is kept closed, and the second valve 5-2 is kept open.

[0029] Further, the trapezoidal pile body is made of steel fiber reinforced concrete pile body, the first spiral water inlet pipe 2-1, the second spiral water inlet pipe 2-2 and the water return pipe 3 are made of PE pipe, and the tee joint 6 and the connecting pipe 7 are made of PE material.

[0030] The specific working principle is as follows:

[0031] The trapezoidal pile body is made of steel fiber concrete and has high structural strength and durability. The pile body is internally provided with a cavity filled with backfill soil to increase heat exchange area. A first spiral water inlet pipe 2-1, a second spiral water inlet pipe 2-2 and a water return pipe 3 are installed in the internal cavity, and the pipes are made of PE material and have good corrosion resistance and thermal stability. The pipes are arranged in an equilateral triangle mode and are fixed by support rods every 3 meters. The first spiral water inlet pipe 2-1 is wrapped with summer phase change material 4-1, and the second spiral water inlet pipe 2-2 is wrapped with winter phase change material 4-2. Through the phase change characteristics of the materials, heat can be stored or released in different seasons, so as to adjust the temperature of the fluid in the pipe. The top ends of the two water inlet pipes are provided with first valve 5-1 and second valve 5-2. By controlling the opening and closing of the valves, the corresponding water inlet pipe can be selected according to the seasonal requirements. For example, in summer, the first valve is opened and the second valve is closed; in winter, the first valve is closed and the second valve is opened, so as to optimize the energy use efficiency. The inlet and outlet of the pipe system are connected with the condenser or evaporator in the heat pump system of the building, so that the underground heat energy can be effectively transported to the building or removed from the building. During system operation, water or other working medium circulates in the pipe, and through heat exchange of the phase change material and the soil, the storage and release of cold and heat energy are realized, so as to achieve the purpose of adjusting the temperature inside the building.

[0032] The novel phase change energy pile not only provides structural support for the building, but also improves energy use efficiency through the stability of ground temperature and the thermal characteristics of phase change material, and realizes the goals of environmental friendliness and energy saving.

[0033] Finally, it should be noted that: the above is only a preferred example of the utility model, and is not used to limit the utility model, although the utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A phase change energy pile suitable for soft soil layers, characterized in that: The trapezoidal pile body is internally provided with a first spiral water inlet pipe, a second spiral water inlet pipe, and a return water pipe. The trapezoidal pile body is internally provided with a first spiral water inlet pipe, a second spiral water inlet pipe, and a return water pipe.

2. The phase change energy pile suitable for soft soil layers according to claim 1, characterized in that: The trapezoidal pile body is externally provided with a straight pipe section and a trapezoidal protruding pipe section in sequence.

3. The phase change energy pile suitable for soft soil layers according to claim 2, characterized in that: The first spiral water inlet pipe is wrapped with summer phase change material, and the second spiral water inlet pipe is wrapped with winter phase change material.

4. The phase change energy pile suitable for soft soil layers according to claim 1, characterized in that: The first spiral water inlet pipe, the second spiral water inlet pipe, and the return water pipe are fixed by the support rods.

5. The phase change energy pile suitable for soft soil layers according to claim 4, characterized in that: The trapezoidal pile body is made of steel fiber reinforced concrete, the first spiral water inlet pipe, the second spiral water inlet pipe, and the return water pipe are made of PE pipe, and the tee joint and the connecting pipe are made of PE material.

6. The phase change energy pile suitable for soft soil layers according to claim 1, characterized in that: ​ 7. The phase change energy pile suitable for soft soil layers according to claim 1, characterized in that: ​

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