阅读说明：本技术 一种阶梯式地埋管组合的土壤蓄放热系统及控制方法 (Stepped buried pipe combined soil heat storage and release system and control method ) 是由 田国良 程会芹 吴玉麒 桑宪辉 吴琪珑 赵小会 左晓栋 于 2021-10-18 设计创作，主要内容包括：本发明给出了一种阶梯式地埋管组合的土壤蓄放热系统及控制方法,包括运行调控管路、地埋管组、土壤环境温度监测组、控制器,运行调控管路用于调控换热介质在地埋管组内的流动运行状态,运行调控管路包括水泵、流量传感器,地埋管组设置在土壤中,换热介质在地埋管组内的流动过程,实现换热介质与地埋管周边土壤的热量交换；土壤环境温度监测组用于监测地埋管组周边土壤环境温度。本发明采用组合阶梯式地埋管进行不同层级的串联进行土壤蓄热与取热,可以适用于不同温度的热源水进行土壤蓄热,利用不同深度土壤的温差实现热量的梯度利用,提高了换热效率和取热效率。(The invention provides a stepped buried pipe combined soil heat storage and release system and a control method, wherein the stepped buried pipe combined soil heat storage and release system comprises an operation regulation and control pipeline, a buried pipe group, a soil environment temperature monitoring group and a controller, the operation regulation and control pipeline is used for regulating and controlling the flowing operation state of a heat exchange medium in the buried pipe group, the operation regulation and control pipeline comprises a water pump and a flow sensor, the buried pipe group is arranged in soil, and the heat exchange between the heat exchange medium and the soil around the buried pipe is realized in the flowing process of the heat exchange medium in the buried pipe group; the soil environment temperature monitoring group is used for monitoring the soil environment temperature around the buried pipe group. The combined stepped type ground pipe is adopted to carry out series connection of different levels to carry out soil heat storage and heat extraction, the combined stepped type ground pipe can be suitable for heat source water with different temperatures to carry out soil heat storage, the temperature difference of soil with different depths is utilized to realize gradient utilization of heat, and the heat exchange efficiency and the heat extraction efficiency are improved.)

1. A stepped buried pipe combined soil heat storage and release system is characterized by comprising an operation regulation and control pipeline, a buried pipe group, a soil environment temperature monitoring group and a controller, wherein the operation regulation and control pipeline is used for regulating and controlling the flowing operation state of a heat exchange medium in the buried pipe group, the operation regulation and control pipeline comprises a water pump and a flow sensor, the buried pipe group is arranged in soil and comprises at least one buried pipe, and the heat exchange between the heat exchange medium and the soil around the buried pipe is realized in the flowing process of the heat exchange medium in the buried pipe; the soil environment temperature monitoring group is used for monitoring the soil environment temperature at the periphery of the buried pipe group, the soil environment temperature monitoring group transmits monitored soil temperature data to the controller, the soil environment monitoring group comprises at least three groups of temperature observation wells, each group is provided with optical fiber temperature sensors of a plurality of different depths in the temperature observation wells, and the controller controls the operation process of the operation regulation and control pipeline.

2. The system according to claim 1, wherein the buried pipe comprises an outer pipe and an inner pipe, the bottom of the outer pipe is closed, the inner pipe is arranged inside the outer pipe, and the bottom of the inner pipe is provided with a through hole for communicating the inner pipe and the outer pipe.

3. The system according to claim 2, wherein the buried pipe group comprises three buried pipes, the centers of the three buried pipes are distributed in an isosceles triangle shape, the buried depths of the three buried pipes are different, the soil environment temperature monitoring group comprises seven groups of temperature observation wells, and the seven groups of temperature observation wells are dug in the soil at different depths.

4. The soil heat storage and release system of claim 3, wherein the operation control pipeline comprises an input main pipe, a reversing control valve set, a circulation pipeline and an output main pipe, the input main pipe is used for guiding a heat exchange medium to enter the reversing control valve set, the output main pipe is used for guiding the heat exchange medium to flow out of the reversing control valve set, the reversing control valve set realizes the switching of the operation heat taking or heat releasing working state of the system by changing the flowing direction of the heat exchange medium in the circulation pipeline, each buried pipe is connected with the circulation pipeline through an opening and closing valve set, the opening and closing valve set is used for controlling the buried pipe to participate in the heat releasing or heat taking process, a third temperature sensor is arranged on a section of the circulation pipeline between the two opening and closing valve sets corresponding to the buried pipe with the largest depth and the buried pipe with the middle depth, and a fourth temperature sensor is arranged on a section of circulating pipeline between two opening and closing valve groups corresponding to the buried pipe with the middle depth and the buried pipe with the shortest depth, and a first temperature sensor is arranged on the input main pipe.

5. A method for controlling a soil heat accumulation and release system of a stepped buried pipe combination according to claim 4, comprising the steps of:

s1, enabling a system operation control program to enter a standby state by a worker;

s2, enabling a system operation control program to enter a heat storage working mode or a heat taking working mode according to seasons by workers, enabling the system to carry out the heat storage working mode in summer, and enabling the buried pipe group to enter different corresponding heat storage working modes by a controller according to a preset control program; in winter, the system carries out a heat-taking working mode, and the controller enables the underground pipe group to enter into corresponding different heat-taking working modes according to a preset control program.

Technical Field

The invention relates to a stepped buried pipe combined soil heat storage and release system and a control method.

Background

The development of clean heating drives the popularization of heat pump technology, solar photo-thermal technology, industrial waste heat recovery and other technologies. However, the problems of excessive solar heat, cold supply by a heat pump, insufficient utilization of waste heat generated in the industrial production process and the like exist in non-heating seasons, and many researches propose a mode of storing heat in soil by solar energy in different seasons, wherein the non-heating seasons store surplus heat in the soil, and the heating seasons take out the heat from the soil. However, in the practical application process, the temperature of the heat source water is greatly fluctuated and unstable due to the problems of change of weather and energy consumption load, uncertainty of geological conditions and the like, the soil heat storage efficiency is reduced, the heat of the heat source water with different temperatures cannot be fully extracted, and the energy waste is caused.

How to efficiently extract heat source water with different temperature ranges for soil heat storage and how to fully extract heat of the heat source water with different temperatures for efficient heat storage on the premise of heat storage and extraction balance is one of the key problems faced by a soil heat storage and extraction system.

Disclosure of Invention

The invention aims to provide a soil heat storage and release system combined by stepped buried pipes and a control method.

The technical scheme adopted by the invention for solving the technical problems is as follows: a stepped buried pipe combined soil heat storage and release system comprises an operation regulation and control pipeline, a buried pipe group, a soil environment temperature monitoring group and a controller, wherein the operation regulation and control pipeline is used for regulating and controlling the flowing operation state of a heat exchange medium in the buried pipe group, the operation regulation and control pipeline comprises a water pump and a flow sensor, the buried pipe group is arranged in soil and comprises at least one buried pipe, and the heat exchange between the heat exchange medium and the soil around the buried pipe is realized in the flowing process of the heat exchange medium in the buried pipe; the soil environment temperature monitoring group is used for monitoring the soil environment temperature at the periphery of the buried pipe group, the soil environment temperature monitoring group transmits monitored soil temperature data to the controller, the soil environment monitoring group comprises at least three groups of temperature observation wells, each group is provided with optical fiber temperature sensors of a plurality of different depths in the temperature observation wells, and the controller controls the operation process of the operation regulation and control pipeline.

Preferably, the buried pipe comprises an outer pipe and an inner pipe, the bottom of the outer pipe is in a closed state, the inner pipe is arranged inside the outer pipe, and the bottom of the inner pipe is provided with a through hole for communicating the inner pipe and the outer pipe.

Furthermore, the buried pipe group comprises three buried pipes, the centers of the three buried pipes are distributed in an isosceles triangle shape, the buried depths of the three buried pipes are different, the soil environment temperature monitoring group comprises seven groups of temperature observation wells, and the digging depths of the seven groups of temperature observation wells in soil are different.

Furthermore, the operation regulation and control pipeline comprises an input main pipe, a reversing regulation and control valve bank, a circulation pipeline and an output main pipe, wherein the input main pipe is used for guiding a heat transfer medium to enter the reversing regulation and control valve bank, the output main pipe is used for guiding the heat transfer medium to flow out of the reversing regulation and control valve bank, the reversing regulation and control valve bank realizes the switching of the operation heating or heat release working state of the system by changing the flow direction of the heat transfer medium in the circulation pipeline, each buried pipe is connected with the circulation pipeline through an opening and closing valve bank, the opening and closing valve bank is used for controlling the buried pipes to participate in the heat release or heat release process, a third temperature sensor is arranged on a section of circulation pipeline between two opening and closing valve banks corresponding to the buried pipe with the largest depth and the buried pipe with the middle depth, a fourth temperature sensor is arranged on a section of circulation pipeline between two opening and closing valve banks corresponding to the buried pipe with the smallest depth and the buried pipe with the middle depth, a first temperature sensor is disposed on the input manifold.

The invention also provides a control method of the stepped buried pipe combined soil heat accumulation and release system, which is characterized by comprising the following steps of:

s1, enabling a system operation control program to enter a standby state by a worker;

s2, enabling a system operation control program to enter a heat storage working mode or a heat taking working mode according to seasons by workers, enabling the system to carry out the heat storage working mode in summer, and enabling the buried pipe group to enter different corresponding heat storage working modes by a controller according to a preset control program; in winter, the system carries out a heat-taking working mode, and the controller enables the underground pipe group to enter into corresponding different heat-taking working modes according to a preset control program.

Furthermore, when the system enters a heat storage working mode, the seven groups of temperature observation wells transmit numerical values to the controller in real time, and the controller calculates data transmitted by the seven groups of temperature observation wells in real time according to a preset calculation method to obtain the numerical values Ta1, Ta2 and Ta3, wherein Ta1 is more than Ta2 is more than Ta 3; then, the temperature value T1 fed back by the first temperature sensor is compared with the values of Ta1, Ta2 and Ta 3;

when T1 is larger than or equal to Ta1, the system enters a high-temperature heat storage working mode, at the moment, the buried pipe with the largest depth enters a heat storage working process, and in the heat storage process of the buried pipe with the largest depth, the controller compares a value T3 monitored by the third temperature sensor with Ta2 and Ta3 in real time;

when T3 is larger than or equal to Ta2, the system controls a corresponding valve opening and closing group to enable the buried pipe with the middle depth to enter the heat storage working process, and the controller compares a value T4 monitored by the fourth temperature sensor with Ta3 in real time in the working process; when T4 is more than or equal to Ta3, the system controls a corresponding opening and closing valve group to enable the buried pipes with the minimum depth to enter the heat storage working process, and at the moment, the three buried pipes enter a series heat storage working mode; when T4 is less than Ta3, the system carries out the serial heat storage working mode of the buried pipe with the maximum depth and the buried pipe with the middle depth;

when the Ta3 is not less than T3 and is less than Ta2, the system controls the corresponding opening and closing valve group to ensure that the buried pipe with the minimum depth also enters the heat storage working process, and at the moment, the buried pipe with the maximum depth and the buried pipe with the minimum depth enter the series heat storage working mode;

when T3 is less than Ta3, the system enters a single-stage heat storage working mode of the buried pipe with the largest depth;

when Ta1 is larger than T1 and is larger than or equal to Ta2, the system enters a medium-temperature heat storage working mode, at the moment, a buried pipe with a central depth enters a heat storage working process, in the heat storage process of the buried pipe with the central depth, the controller compares a value T4 monitored by the fourth temperature sensor with Ta3 in real time, and when T4 is larger than or equal to Ta3, the system controls a corresponding opening and closing valve group to enable the buried pipe with the minimum depth to also enter the heat storage working process, and at the moment, the buried pipe with the central depth and the buried pipe with the minimum depth enter a series heat storage working mode; when T4 is less than Ta3, the system is in a single-stage heat storage working mode of the buried pipe with a central depth;

when Ta2 is greater than T1 and is larger than or equal to Ta3, the system enters a low-temperature heat storage working mode, and at the moment, the buried pipe with the minimum depth performs single-stage heat storage.

And when T1 < Ta3, stopping the heat storage operation.

Furthermore, when the system enters a heat taking working mode, the seven groups of temperature observation wells transmit values to the controller in real time, and the controller calculates data transmitted by the seven groups of temperature observation wells in real time according to a preset calculation method to obtain Tb1, Tb2 and Tb3 values, wherein Tb1 is greater than Tb2 is greater than Tb 3; then, the temperature value T1 fed back by the first temperature sensor is compared with the Tb1, Tb2 and Tb3 values;

(1) when T1 is less than Tb3, the system enters a low-temperature heat-taking working mode, at the moment, the buried pipe with the minimum depth enters a heat-taking working process, and in the process of heat-taking of the buried pipe with the minimum depth, the controller compares a value T4 monitored by the fourth temperature sensor with Tx (set water outlet temperature) in real time;

when T4 is less than Tx, the system controls a corresponding opening and closing valve group to enable the buried pipe with the middle depth to enter the heat taking working process, and in the working process, the controller compares a value T3 monitored by the third temperature sensor with Tx in real time; when T3 is less than Tx, the system controls a corresponding opening and closing valve group to enable the buried pipes with the largest depth to enter the heat taking working process, and at the moment, the three buried pipes enter a series heat taking working mode; when T3 is more than or equal to Tx, the system carries out the series connection of the buried pipe with the minimum depth and the buried pipe with the middle depth to obtain heat in a working mode;

when T4 is more than or equal to Tx, the system enters a single-stage heat-extraction working mode of the buried pipe with the minimum depth;

(2) when Tb3 is not more than T1 and Tb2, the system enters a medium temperature heat extraction working mode, at the moment, the buried pipe with the central depth enters a heat extraction working process, in the process of heat extraction of the buried pipe with the central depth, the controller compares a value T3 monitored by the third temperature sensor with Tx in real time, when T3 is less than Tx, the system controls a corresponding opening and closing valve group to enable the buried pipe with the largest depth to also enter the heat extraction working process, and at the moment, the buried pipe with the central depth and the buried pipe with the largest depth enter a series heat extraction working mode; when T3 is more than or equal to Tx, the system is in a single-stage heat extraction working mode of the buried pipe with the depth being centered;

(3) when Tb2 is not more than T1 is more than Tb1, the system enters a high-temperature heat-taking working mode, and at the moment, the buried pipe with the largest depth carries out single-stage heat-taking;

(4) when T1 is more than or equal to Tb1, the heat extraction work is stopped.

The invention has the beneficial effects that: the combined stepped buried pipe is adopted to carry out series connection of different levels to carry out soil heat storage and heat extraction, and the combined stepped buried pipe can be suitable for heat source water with different temperatures to carry out soil heat storage in summer; in winter, the temperature difference of the soil at different depths is utilized to realize the gradient utilization of heat, so that the heat exchange efficiency and the heat extraction efficiency are improved; meanwhile, a valve combination mode is provided, so that the heat exchange of water flow can be realized only by switching the state combination of the valves on the premise of not increasing a water pump, and the system cost is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are part of the preferred embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of the framework of the present invention;

FIG. 2 is a cross-sectional view of the buried pipe with the largest depth buried in the soil;

FIG. 3 is a top view of the buried pipe with the largest depth buried in the soil;

FIG. 4 is an enlarged view of FIG. 2 at B;

FIG. 5 is an enlarged view taken at A in FIG. 2;

FIG. 6 is a top view of the distribution of the buried pipe set and the soil environment temperature monitoring component;

FIG. 7 is a schematic diagram of the deep distribution of seven groups of temperature observation wells;

FIG. 8 is a schematic view of the direction of medium flow inside the buried pipe with the largest depth during the heat storage process of the system;

FIG. 9 is a schematic view showing the direction of medium flowing inside the buried pipe with the largest depth during the heat removal process of the system;

FIG. 10 is a schematic control flow chart of the system for performing heat storage operation;

FIG. 11 is a schematic control flow chart of the system for heat removal;

in the figure: 1 water pump, 2 flow sensor, 3-way control valve group, 41-depth buried pipe, 411 outer pipe, 412 inner pipe, 4121 circulation port, 413 sealing end cover, 4131 first through port, 4132 second through port, 42-depth centered buried pipe, 43-depth minimum buried pipe, 5 soil, 51 well wall, 6 insulation layer, 71 first temperature observation well, 72 second temperature observation well, 73 third temperature observation well, 74 fourth temperature observation well, 75 fifth temperature observation well, 76 sixth temperature observation well, 77 seventh temperature observation well, 101 input header pipe, 102 second pipe, 103 third pipe, 104 circulation pipe, 105 output header pipe, 106 sixth pipe, 107 seventh pipe, 108 eighth pipe, 201EV1 control valve, 202EV2 control valve, 203EV3 control valve, 204EV4 control valve, 205EV5 control valve, 206EV6 control valve, 207EV7 control valve, 208EV8 control valve, 209EV9 control valve, 210EV10 control valve, 211EV11 control valve, 212EV12 control valve, 213EV13 control valve, 301 first temperature sensor, 302 second temperature sensor, 303 third temperature sensor, 304 fourth temperature sensor, 401 first pressure sensor, 402 second pressure sensor, 403 third pressure sensor, 404 fourth pressure sensor.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the specific embodiments and accompanying drawings 1 to 11, and it is obvious that the described embodiments are only a part of the preferred embodiments of the present invention, and not all embodiments. Those skilled in the art can make similar modifications without departing from the spirit of the invention, and therefore the invention is not limited to the specific embodiments disclosed below.

The invention provides a stepped buried pipe combined soil heat storage and release system (shown in figure 1), which comprises an operation regulation and control pipeline, a buried pipe group, a soil environment temperature monitoring group and a controller, wherein the operation regulation and control pipeline is used for regulating and controlling the flowing operation state of a heat exchange medium in the buried pipe group, the operation regulation and control pipeline comprises a water pump 1 and a flow sensor 2, the water pump 1 provides power for the flowing of the heat exchange medium to ensure the normal flowing of the heat exchange medium in the operation process of the system, and the flow sensor 2 is used for monitoring the total flow condition of the heat exchange medium reflowing by the system; buried pipe group sets up in soil 5, and buried pipe group includes at least one buried pipe, and heat transfer medium realizes heat exchange medium and the peripheral soil 5's of buried pipe heat exchange process in buried pipe, in this embodiment, for the maximize of making buried pipe and soil heat transfer contact surface, simultaneously, make heat transfer medium fully diffuse flow in buried pipe to guarantee to flow the in-process, realize better heat exchange effect, here, buried pipe's embodiment is: the buried pipe comprises an outer pipe and an inner pipe, the bottom of the outer pipe is in a closed state, the inner pipe is arranged inside the outer pipe, the bottom of the inner pipe is provided with a flow port for communicating the inner pipe and the outer pipe, when heat is stored in soil, a heat exchange medium enters from the inner pipe, then flows out of the outer pipe, the outer pipe releases heat to the soil, and the heat storage process is realized; when heat is taken from soil, a heat exchange medium enters from the outer pipe and then flows out from the inner pipe, and the outer pipe absorbs heat from the soil, so that the heat taking process is realized; the soil environment temperature monitoring group is used for monitoring the soil environment temperature at the periphery of the buried pipe group, the soil environment temperature monitoring group transmits monitored soil temperature data to the controller, the soil environment monitoring group comprises at least three temperature observation wells, each group is provided with optical fiber temperature sensors of a plurality of different depths in the temperature observation wells, and the controller controls the operation process of the operation regulation and control pipeline. The temperature observation well is buried in soil and used for monitoring the temperature of soil around the buried pipe in real time.

In the above embodiment, a specific implementation of a specific embodiment of the combination of the underground pipe set and the soil environment temperature monitoring set is as follows: as shown in fig. 6, the buried pipe group comprises three buried pipes, the centers of the three buried pipes are distributed in an isosceles triangle shape, and the buried depths of the three buried pipes are different, the soil environment temperature monitoring group comprises seven groups of temperature observation wells, the buried depths of the seven groups of temperature observation wells in the soil are different, wherein the three temperature observation wells are respectively superposed with the corresponding three buried pipes, namely each buried pipe is equivalent to one temperature observation well, a plurality of optical fiber temperature sensors corresponding to the observation wells are correspondingly and sequentially arranged on the outer side wall of the buried pipe at equal intervals, the real-time heat exchange condition of the corresponding buried pipe is calculated by using the data monitored by the temperature observation wells superposed with the buried pipes, one temperature observation well is arranged at the center position of the distribution area of the three buried pipes, and the rest three temperature observation wells are distributed at equal intervals at the periphery of the three buried pipes along the circumferential direction of the central axis of the distribution area of the three buried pipes, in practical application, the vertical distance between adjacent optical fiber temperature sensors in the temperature observation wells can be set to be 25m, and the number of the optical fiber temperature sensors is determined by the depth of the corresponding temperature observation well, for example, when the depth of one temperature observation well is 200m, the number of the optical fiber temperature sensors arranged in the temperature observation well is 8, and when the depth of one temperature observation well is 50m, the number of the optical fiber temperature sensors arranged in the temperature observation well is 2. Specifically, the three buried pipes are respectively: the buried pipe 41 with the maximum depth, the buried pipe 42 with the middle depth and the buried pipe 43 with the minimum depth, wherein the buried depth range of the buried pipe 41 with the maximum depth is 150-200 m; the burying depth range of the buried pipe 42 with the middle depth is 100-150 m; the burying depth range of the buried pipe 43 with the minimum depth is 30-100 m; the embodiment of the buried pipe 41 with the largest depth is as follows: the device comprises an outer pipe 411, an inner pipe 412 and a sealing end cover 413, wherein the sealing end cover 413 is used for sealing the upper openings of the outer pipe 411 and the inner pipe 412; a first through hole 4131 penetrating the inner tube 412 and a second through hole 4132 penetrating the outer tube 411 are formed in the sealing end cap 413; the bottom of the outer tube 411 is closed, the inner tube 412 is arranged inside the outer tube 411, the bottom of the inner tube 412 is provided with a flow port 4121 for communicating the inner tube 412 and the outer tube 411, when heat is stored in soil, the heat exchange medium flows into the inner tube 412 from the first through hole 4131, then flows into the outer tube 411 through the flow port 4121, and flows out from the two second through holes 4132, so that the heat storage process is realized; when heat is taken from the soil, the heat exchange medium flows into the outer tube 411 from the two second through holes 4132, then flows into the inner tube 412 through the flow hole 4121, and flows out from the first through hole 4131, thereby realizing a heat taking process. The embodiment of burying the buried pipe 41 with the maximum depth in the soil is shown in fig. 2, the buried pipe 41 with the maximum depth is buried vertically, the periphery of the buried pipe is reinforced by a well-fixing wall 51, an insulating layer 6 is arranged on the upper part of the buried pipe, and a layer of soil 5 is further paved on the upper part of the insulating layer 6. The specific embodiments of the buried pipe 42 with the middle depth and the buried pipe 43 with the minimum depth are the same as the specific structure and the heat accumulation and release processes of the buried pipe 41 with the maximum depth, and detailed description is omitted; the seven groups of temperature observation wells are respectively as follows: a first temperature observation well 71, a second temperature observation well 72, a third temperature observation well 73, a fourth temperature observation well 74, a fifth temperature observation well 75, a sixth temperature observation well 76 and a seventh temperature observation well 77, wherein the first temperature observation well 71 is distributed in the centers of the three buried pipe distribution areas, and the buried depth is 25 m; the second temperature observation well 72, the third temperature observation well 73 and the fourth temperature observation well 74 are distributed at equal intervals along the periphery of the three buried pipe distribution areas, and the buried depths of the second temperature observation well, the third temperature observation well and the fourth temperature observation well are 50m, 100m and 125m in sequence; the fifth temperature observation well 75, the sixth temperature observation well 76 and the seventh temperature observation well 77 are sequentially overlapped with the buried pipe 43 with the minimum depth, the buried pipe 42 with the middle depth and the buried pipe 41 with the maximum depth one by one, the buried depths are respectively 150m, 175m and 200m, and the specific number of the optical fiber temperature sensors in the seven groups of temperature observation wells is determined according to the depth of the corresponding observation well. The seven groups of temperature observation wells transmit the monitoring values to the controller, and the controller can correspondingly analyze the distribution condition of the thermal field around each buried pipe according to data and simultaneously analyze the distribution condition of the thermal field around the whole distribution area of the three buried pipes.

The specific implementation mode of the operation regulation pipeline is as follows: the operation regulation and control pipeline comprises an input main pipe 101, a reversing regulation and control valve group 3, a circulating pipeline 104 and an output main pipe 105, a water pump 1 is arranged on the input main pipe 101, the input main pipe 101 is used for guiding a heat transfer medium to enter the reversing regulation and control valve group 3, the output main pipe 105 is used for guiding the heat transfer medium to flow out of the reversing regulation and control valve group 3, a flow sensor 2 is arranged on the output main pipe 105, the reversing regulation and control valve group 3 realizes the switching of the operation heat taking or heat releasing working state of the system by changing the flowing direction of the heat transfer medium in the circulating pipeline 104, each buried pipe is connected with the circulating pipeline through an opening and closing valve group, the opening and closing valve group is used for controlling the buried pipe to participate in the heat releasing or heat taking process, and a third temperature sensor 303 is arranged on a section of the circulating pipeline between two opening and closing valve groups corresponding to the buried pipe 41 with the largest depth and the buried pipe 42 with the middle depth, a third pressure sensor 403 is arranged on one side of the third temperature sensor 303, a fourth temperature sensor 304 is arranged on one section of the circulating pipeline between the two opening and closing valve groups corresponding to the buried pipe 42 with the central depth and the buried pipe 43 with the minimum depth, a fourth pressure sensor 404 is arranged on one side of the fourth temperature sensor 304, a first temperature sensor 301 is arranged on the input main pipe 1, and a second temperature sensor 302 and a second pressure sensor 402 are arranged on the output main pipe 105.

In the above embodiment, the specific implementation manner of combining the input main pipe 101, the reversing control valve group 3, the circulation pipeline 104, the output main pipe 105, the opening and closing valve group, and the three buried pipes is as follows: the reversing regulating and controlling valve group 3 comprises a second pipeline 102 and a third pipeline 103, a circulating pipeline 104 is a pipeline, the second pipeline 102 and the third pipeline 103 are connected in series with an input manifold 101 and an output manifold 105 in a parallel mode, an EV1 control valve 201 and an EV2 control valve 202 are connected in series on the second pipeline 102, an EV3 control valve 203 and an EV4 control valve 204 are connected in series on the third pipeline 103, the EV1 control valve 201 and the EV3 control valve 203 are both adjacent to the input manifold 101, one end of the circulating pipeline 104 is communicated with a section of the second pipeline 102 between the EV1 control valve 201 and the EV2 control valve 202, and the other end of the circulating pipeline 104 is communicated with a section of the third pipeline 103 between the EV3 control valve 203 and the EV4 control valve 204; the opening and closing control valve group corresponding to the buried pipe 41 with the largest depth is an opening and closing valve group 1, the opening and closing control valve group corresponding to the buried pipe 42 with the smallest depth is an opening and closing valve group 2, the opening and closing control valve group corresponding to the buried pipe 43 with the smallest depth is an opening and closing valve group 3, wherein the opening and closing valve group 1 comprises a seventh pipeline 107 led out from two second through holes 4132 respectively, a sixth pipeline 106 led out from a first through hole 4131, the two seventh pipelines 107 are communicated with a circulation pipeline 104 through an eighth pipeline after being connected in parallel, the sixth pipeline 106 is communicated with the circulation pipeline 104, the opening and closing valve group 1 further comprises an EV17 control valve 207, an EV11 control valve 205 and an EV12 control valve 206, wherein the EV17 control valve 207 is arranged on the circulation pipeline 104 at one end between the intersection of the sixth pipeline 106 and the intersection of the circulation pipeline 104, the EV11 control valve 205 is arranged on the sixth pipeline, the EV12 control valve 206 is arranged on the eighth pipeline, when the EV17 control valve 207 is closed, the EV11 control valve 205 and the EV12 control valve 206 are opened, the buried pipe 41 with the largest depth is made to participate in the heat taking or heat releasing working process, and when the EV17 control valve 207 is opened, the EV11 control valve 205 and the EV12 control valve 206 are closed, the buried pipe 41 with the largest depth is made not to participate in the heat taking or heat releasing working process; the opening and closing valve group 2 comprises an EV18 control valve 210, an EV13 control valve 208 and an EV14 control valve 209, the opening and closing valve group 3 comprises an EV19 control valve 213, an EV15 control valve 211 and an EV16 control valve 212, and the EV13 control valve 208 and the EV15 control valve 211 are installed by adopting the same specific setting principle as the EV11 control valve 205; wherein the EV14 control valve 209 and the EV16 control valve 212 are installed using the same specific arrangement principle as the EV12 control valve 206, and wherein the EV18 control valve 210 and the EV19 control valve 213 are installed using the same specific arrangement principle as the EV17 control valve 207; the principle of the working mode of the buried pipe corresponding to the control of the opening and closing valve group 2 and the opening and closing valve group 3 is the same as the working principle of the buried pipe corresponding to the control of the opening and closing valve group 1, so detailed description is not needed here.

The invention also provides a control method of the stepped buried pipe combined soil heat accumulation and release system, which comprises the following steps:

s1, enabling a system operation control program to enter a standby state, wherein before the control program enters the standby state, a worker can check whether each execution element in the system has starting and operation faults in advance, and if yes, the system is operated after the faults are removed;

s2, according to the seasons, the system operation control program enters a heat storage working mode or a heat taking working mode, the system is mainly applied in the northern cold season with heating demand, in the summer and winter, the summer and winter also refer to the season of the summer and winter in the northern area of China; in summer, the system carries out a heat storage working mode, and the controller enables the buried pipe group to enter the corresponding heat storage working mode according to a preset control program; in winter, the system carries out a heat-taking working mode, and the controller enables the underground pipe group to enter the corresponding heat-taking working mode according to a preset control program.

In the initial stage of the system performing the heat storage mode, the controller opens the EV3 control valve 203, the EV2 control valve 202, the EV17 control valve 207, the EV18 control valve 210 and the EV19 control valve 213, and the remaining control valves are in the closed state; the controller calculates the data transmitted by the seven groups of temperature observation wells in real time according to a preset calculation method to obtain Ta1, Ta2 and Ta3 values, wherein the specific calculation mode is as follows: the controller can count the temperature acquisition values of the soil with the same depth through the temperature data monitored by the seven groups of temperature observation wells in real time, further analyze the distribution condition of the thermal field of the peripheral soil, and then calculate the values of Ta1, Ta2 and Ta3, wherein the value of Ta1 is obtained by obtaining a calculated value according to a set logic and adding a minimum heat exchange temperature difference value to the acquisition value of the seventh temperature observation well 77; the value of Ta2 is obtained by adding a minimum heat exchange temperature difference value to a calculated value obtained by the set logic of the collected value of the sixth temperature observation well 76; the Ta3 value is obtained by adding a minimum heat exchange temperature difference value to a calculated value obtained by a set logic of the collected value of the fifth temperature observation well 75; as is known in the art, the soil temperature increases with the depth within a certain ground surface depth range, and therefore, the burying depth of the seventh temperature observation well 77, the sixth temperature observation well 76, and the fifth temperature observation well 75 can be deduced, and Ta1 is greater than Ta2 is greater than Ta 3; after calculating the corresponding values of Ta1, Ta2 and Ta3, the controller compares the temperature value T1 fed back by the first temperature sensor 301 with the values of Ta1, Ta2 and Ta 3; the above comparison process has four comparison results as follows: t1 is more than or equal to Ta1, Ta1 is more than T1 is more than or equal to Ta2, Ta2 is more than T1 is more than or equal to Ta3, T1 is less than Ta3, and the system correspondingly and directly enters different heat storage working modes according to the four different comparison results; the specific working mode flow is as follows:

(1) when T1 is larger than or equal to Ta1, opening an EV11 control valve 205 and an EV12 control valve 206, and closing an EV17 control valve 207, so that the system enters a high-temperature heat storage working mode, at the moment, the buried pipe 41 with the largest depth enters a heat storage working process, and in the heat storage process of the buried pipe 41 with the largest depth, the controller compares a value T3 monitored by the third temperature sensor 303 with Ta2 and Ta3 in real time;

when T3 is more than or equal to Ta2, the system controls a corresponding valve group to enable the buried pipe 42 with the middle depth to enter the heat storage working process, specifically, the system opens an EV13 control valve 208 and an EV14 control valve 209 and closes an EV18 control valve 210; here, during the operation, the controller compares the value T4 monitored by the fourth temperature sensor 304 with Ta3 in real time; when T4 is more than or equal to Ta3, the system controls a corresponding valve group to enable the buried pipe 43 with the minimum depth to enter the heat storage working process, specifically, the system opens an EV15 control valve 211 and an EV16 control valve 212 and closes an EV19 control valve 213, and at the moment, the three buried pipes enter a series heat storage working mode; when T4 is less than Ta3, the system carries out the serial heat storage working mode of the buried pipe 41 with the maximum depth and the buried pipe 42 with the middle depth;

when the Ta3 is not less than T3 and is less than Ta2, the system controls a corresponding valve group to enable the buried pipe 43 with the minimum depth to enter the heat storage working process, specifically, the system opens an EV15 control valve 211 and an EV16 control valve 212 and closes an EV19 control valve 213, and at the moment, the buried pipe 41 with the maximum depth and the buried pipe 43 with the minimum depth enter a series heat storage working mode;

when T3 is less than Ta3, the system enters a single-stage heat storage working mode of the ground buried pipe 41 with the largest depth;

(2) when Ta1 is greater than T1 and is not less than Ta2, the system enters a medium-temperature heat storage working mode, at the moment, the buried pipe 42 with the middle depth enters a heat storage working process, specifically, the system opens an EV13 control valve 208 and an EV14 control valve 209, and closes an EV18 control valve 210; in the process of heat storage of the buried pipe 42 with the central depth, the controller compares a value T4 monitored by the fourth temperature sensor 304 with Ta3 in real time, and when T4 is not less than Ta3, the system controls a corresponding valve group to enable the buried pipe 43 with the minimum depth to enter the heat storage working process, specifically, the system opens an EV15 control valve 211 and an EV16 control valve 212 and closes an EV19 control valve 213; at this time, the buried pipe 42 with the middle depth and the buried pipe 43 with the minimum depth enter a series heat storage working mode; when T4 is less than Ta3, the system is in a single-stage heat storage working mode of the buried pipe 42 with the middle depth;

(3) when Ta2 is greater than T1 and is larger than or equal to Ta3, the system enters a low-temperature heat storage working mode, specifically, the system opens the EV15 control valve 211 and the EV16 control valve 212 and closes the EV19 control valve 213, and at the moment, the buried pipe 43 with the minimum depth performs single-stage heat storage.

(4) When T1 < Ta3, the heat storage operation is stopped, and specifically, the system stops the water pump 1.

At the initial stage of the system for carrying out a heating hot mode, opening an EV1 control valve 201, an EV4 control valve 204, an EV17 control valve 207, an EV18 control valve 210 and an EV19 control valve 213 by a controller, closing the rest control valves, transmitting numerical values to the controller by seven groups of temperature observation wells in real time, and calculating data transmitted by the seven groups of temperature observation wells by the controller according to a preset calculation method to obtain numerical values Tb1, Tb2 and Tb 3; the specific calculation method is as follows: the controller can count the temperature acquisition values of the soil with the same depth through the temperature data monitored by the seven groups of temperature observation wells in real time, further analyze the distribution condition of the thermal field of the surrounding soil, and then calculate the values of Tb1, Tb2 and Tb3, wherein the value of Tb1 is obtained by obtaining a calculated value according to a set logic and adding a minimum heat exchange temperature difference value to the acquisition value of the seventh temperature observation well 77; the value of Tb2 is obtained by adding a minimum heat exchange temperature difference value to a calculated value obtained by the set logic of the collected value of the sixth temperature observation well 76; the value of Tb3 is obtained by adding a minimum heat exchange temperature difference to a calculated value obtained by the set logic of the collected value of the fifth temperature observation well 75; the minimum heat exchange temperature difference is determined by workers according to the heat exchange characteristics of soil and buried pipes and experience. As is known in the art, the soil temperature increases with the depth within a certain ground surface depth range, and therefore, Tb1 > Tb2 > Tb3 can be derived from the burying depths of the seventh temperature observation well 77, the sixth temperature observation well 76, and the fifth temperature observation well 75; then, the temperature value T1 fed back by the first temperature sensor is compared with the Tb1, Tb2 and Tb3 values; the above comparison process has four comparison results as follows: t1 is more than or equal to Tb3, Tb3 is more than or equal to T1 is more than or equal to Tb2, Tb2 is more than or equal to T1 is more than Tb1, and T1 is more than or equal to Tb 1; according to the four different comparison results, the system directly enters different heat taking working modes correspondingly, and the specific working mode flow is as follows:

(1) when T1 is less than Tb3, the system enters a low-temperature heat extraction working mode, specifically, the system opens an EV15 control valve 211 and an EV16 control valve 212 and closes an EV19 control valve 213, at this time, the buried pipe 43 with the smallest depth enters a heat extraction working process, and in the process of extracting heat from the buried pipe 43 with the smallest depth, the controller compares a value T4 monitored by the fourth temperature sensor 304 with Tx (set outlet water temperature) in real time;

when T4 is less than Tx, the system controls a corresponding valve group, specifically, the system opens an EV13 control valve 208 and an EV14 control valve 209 and closes an EV18 control valve 210, so that the buried pipe 42 with the middle depth also enters the heat extraction working process, and in the working process, the controller compares a value T3 monitored by a third temperature sensor 303 with Tx in real time; when T3 is less than Tx, the system controls a corresponding valve group, specifically, an EV11 control valve 205 and an EV12 control valve 206 are opened, and an EV17 control valve 207 is closed, so that the buried pipe 41 with the largest depth also enters the heat extraction working process, and at the moment, the three buried pipes enter a series heat extraction working mode; when T3 is more than or equal to Tx, the system carries out the series connection heat extraction working mode of the buried pipe 43 with the minimum depth and the buried pipe 42 with the middle depth;

when T4 is more than or equal to Tx, the system enters a single-stage heat-taking working mode of the buried pipe 43 with the minimum depth;

(2) when Tb3 is not more than T1 and less than Tb2, the system enters a medium temperature heat extraction working mode, specifically, the system opens an EV13 control valve 208 and an EV14 control valve 209 and closes an EV18 control valve 210, at this time, the buried pipe 42 with the central depth enters a heat extraction working process, during the heat extraction process of the buried pipe 42 with the central depth, the controller compares a value T3 monitored by a third temperature sensor 303 with Tx in real time, when T3 is less than Tx, the system controls a corresponding valve group, specifically, opens an EV11 control valve 205 and an EV12 control valve 206 and closes an EV17 control valve 207, so that the buried pipe 41 with the maximum depth also enters the heat extraction working process, and at this time, the buried pipe 42 with the central depth and the buried pipe 41 with the maximum depth enter a series heat extraction working mode; when T3 is more than or equal to Tx, the system is in a single-stage heat extraction working mode of the buried pipe 42 with the depth being centered;

(3) when Tb2 is not more than T1 and Tb1, the system enters a high-temperature heat extraction working mode, specifically, an EV11 control valve 205 and an EV12 control valve 206 are opened, an EV17 control valve 207 is closed, and at the moment, the buried pipe 41 with the largest depth performs single-stage heat extraction;

(4) and when the T1 is more than or equal to the Tb1, the heat extraction work is stopped, and specifically, the water pump 1 stops working.

In addition to the technical features described in the specification, the technology is known to those skilled in the art.

While the preferred embodiments and examples of the present invention have been described in detail, it will be apparent to those skilled in the art that the invention is not limited thereto, and that various changes and modifications may be made without departing from the spirit and scope of the invention.