CN213777870U

CN213777870U - Heat storage type geothermal energy full-well-section dry well heat production system

Info

Publication number: CN213777870U
Application number: CN202022331331.7U
Authority: CN
Inventors: 张伟; 刘东喜; 张家琪; 孟庆瑶; 吕心力; 任亚鹏; 柳佳丽
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2020-10-20
Filing date: 2020-10-20
Publication date: 2021-07-23
Anticipated expiration: 2030-10-20

Abstract

The utility model relates to a heat storage formula geothermal energy full-well section dry well heat recovery system, including adopting hot heating unit and underground and adopting hot unit, the underground is adopted hot unit and is included the center tube, and coaxial cover is equipped with the sleeve pipe outside this center tube, and the center tube cartridge link up through the low temperature layer and the high temperature layer of geothermal well, and the sleeve pipe cartridge is on the low temperature layer. The system breaks the dependence of a geothermal heating building group on a hydrothermal geothermal heating system, can convert dry geothermal wells without water or with less water yield into a single-well exploitation system, fully utilizes each geothermal well, can reduce the number of geothermal wells under the same heating condition, further reduces the initial investment of the geothermal heating system, and has remarkable economic advantage.

Description

Heat storage type geothermal energy full-well-section dry well heat production system

Technical Field

The utility model belongs to geothermal resources exploitation utilizes the field, relates to deep carbonate rock geothermal resources exploitation and utilizes the technique, concretely relates to heat storage formula geothermal energy full-well section dry well heat recovery system.

Background

The economic construction of China is rapidly developed, the demand on energy is rapidly increased, the traditional energy sources such as coal and the like have serious influence on the ecological environment, and the increase of the development and utilization of clean renewable energy sources is an important measure for changing the energy development mode and adjusting the energy structure.

Deep carbonate geothermal resources are more and more taken into consideration in the north heating as clean energy, and for the development of the geothermal energy in the middle and deep layers, the current domestic main mode is a mode of extracting underground hot water for mining, namely hot water is extracted from the underground with the depth of tens of meters to thousands of meters, and then the heat energy is extracted through a heat exchange system arranged on the ground. The mode has higher requirement on site selection of buildings, and when the geothermal well is drilled, the geothermal well with low water yield or even without water and dry heat rocks appears frequently, so that the investment risk of enterprises is increased, and the rapid large-scale popularization of geothermal heating is hindered to a certain extent. In contrast, experts and scholars propose a dry geothermal well scheme with less water yield or no water for single-well closed cyclic utilization, but the scheme has the problems of serious heat exchange loss in the heat extraction process, low wellhead water outlet temperature and the like.

In order to widen the utilization range of deep carbonate rock geothermal resources and solve the problems of the existing geothermal well mining system with little or no water in the middle-deep layer, the utility model provides a heat storage type geothermal energy full-well section dry well heat-mining system, the system can utilize the dry geothermal well with little water yield or no water, breaks through the limitation of the traditional hydrothermal geothermal well on the dependence on underground hot water in the mining process, and for the production-injection type geothermal wells which are required to be shut down according to the national policy and cannot be recharged, the system can convert the system into a single-well exploitation system, can solve the problems of serious heat loss, low water outlet temperature and the like in the heat extraction process in the conventional system utilizing the dry geothermal well with little water yield or no water, and in addition, the system can realize the summer heat storage process of the low-temperature section of the geothermal well, and further reduces the heat loss of hot water in the pipe at the low-temperature section of the geothermal well in the heat taking process.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's weak point, it is serious to provide a get hot in-process heat loss that exists in the system that can effectively solve the current dry-type geothermal well that utilizes the water yield to lack or anhydrous, and leaving water temperature hangs down the scheduling problem, is applied to the whole well section dry-well heat production system of hot type geothermal energy of heating in winter and summer heat accumulation operating mode simultaneously.

The utility model provides a its technical problem take following technical scheme to realize:

a heat storage type geothermal energy full-well section dry well heat collection system comprises a heat collection and heating unit and an underground heat collection and heating unit, wherein the heat collection and heating unit is arranged on the ground and comprises a heat pump unit, a water injection pump and a water suction pump; the underground heat production unit is arranged in an underground well and comprises a central pipe, a sleeve is coaxially sleeved outside the central pipe, the central pipe is inserted into a low-temperature layer and a high-temperature layer which penetrate through the underground well, the sleeve is inserted into the low-temperature layer, and the central pipe, the sleeve and the underground well wall form an outer layer channel, a middle layer channel and an inner layer channel.

The utility model provides a heat storage formula geothermal energy full-well section dry well heat recovery system, includes heating return circuit and heat accumulation return circuit, the heating return circuit constitute by heat pump set, middle level water injection pump, middle level passageway, inlayer suction pump and inlayer water pump valve, the heat accumulation return circuit constitute by middle level water injection pump, middle level passageway, outer water pump valve, outer suction pump, still including preheating the heat preservation return circuit, should preheat the heat preservation return circuit and constitute by heat pump set, outer water injection pump, outer water injection valve, outer passageway, inlayer suction pump and bypass valve.

And, water injection pump and suction pump all set up subaerial.

The application of a heat storage type geothermal energy full-well section dry well heat recovery system comprises the following steps: in winter, a preheating and heat-insulating loop is formed first, and then the preheating and heat-insulating loop is closed to form a heating loop.

The application of a heat storage type geothermal energy full-well section dry well heat recovery system comprises the following steps: the heat is stored in summer to form a heat storage loop.

The utility model has the advantages that:

1. the utility model provides a heat storage formula geothermal energy whole-well section dry well heat recovery system can preheat the geothermal well delivery port through setting up bypass system on inlayer exhalant canal before the heating to can form the stable waters heat preservation of one deck in the cover intraductal formation, improved geothermal well export geothermal water's temperature, and then improved geothermal water's heat of getting and utilization efficiency.

2. The utility model provides a heat storage formula geothermal energy full-well section dry well heat recovery system includes heating return circuit and heat accumulation return circuit, and the innovation increases and preheats the heat preservation return circuit, can carry out the heat-retaining to geothermal well low temperature section in summer. The heat carried in high-temperature hot water in summer is stored in rock stratums of the low-temperature sections in a mode of internal injection and external injection between the sleeves of the low-temperature sections of the geothermal wells, and the heat stored in the low-temperature sections and the heat in the rock stratums of the high-temperature sections can be simultaneously taken out and utilized during heating in winter, so that the whole-well section heat recovery of the system is realized.

3. The utility model provides a heat storage formula geothermal energy whole well section dry-well heat recovery system has broken geothermal heating building group to hydrothermal type geothermal heating system's dependence, to anhydrous or less dry-type geothermal well of water yield, adopts the utility model provides a heat recovery system can adopt the geothermal water who satisfies user demand. For the production-injection geothermal wells which are required to be shut down according to national policies and cannot be recharged, the system can be converted into a single-well mining system, each geothermal well is fully utilized, the number of the geothermal wells can be reduced under the same heating condition, the initial investment of the geothermal heating system is further reduced, and the economic advantage is obvious.

Drawings

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

FIG. 2 is a schematic view of the flow direction of the system preheating and heat-preserving loop of the present invention;

FIG. 3 is a schematic view of the water flow direction of the heating loop of the system of the present invention;

fig. 4 is a schematic view of the flow direction of the heat storage loop of the system of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are provided for illustrative purposes only, and are not intended to be limiting, and the scope of the present invention should not be limited thereby.

The utility model provides a heat-retaining formula geothermal energy full-well section drywell heat recovery system, as shown in figure 1, including adopting hot heating unit and adopting hot unit in the underground, it includes heat pump set 1 to adopt hot heating unit, water injection pump and suction pump, the water injection pump includes middle level water injection pump 2 and outer water injection pump 17, the suction pump includes inlayer suction pump 11 and outer suction pump 16, inlayer pump front end is installed inlayer suction pump inlayer and is drawn water valve and bypass valve, inlayer pump valve 13 is used for controlling inlayer water injection pump 11, way valve 12 is used for controlling middle level water injection pump 2, outer water injection valve 14 is used for controlling outer water injection pump 17, outer pump valve 15 is used for controlling outer suction pump 16.

The underground heat production unit is arranged in an underground well, the heat production unit comprises a central pipe 3, a sleeve 4 is coaxially sleeved outside the central pipe, the central pipe is inserted into a low-temperature layer and a high-temperature layer which penetrate through the underground well, and the sleeve is inserted into the low-temperature layer.

The outer layer channel 6, the middle layer channel 7 and the inner layer channel 8 are formed by the central tube, the sleeve and the geothermal well wall, the metal well wall is adopted by the geothermal well, the high-density polyethylene tube is adopted by the sleeve, a heat-insulating layer is not required to be added between the central tube and the sleeve, and a water area heat-insulating layer is formed by a geothermal well bypass circulating system.

The heating and heat supplying unit of the system is arranged above the ground, under the working condition of heating in winter, a heat pump unit 1, an outer water injection pump 17, an outer water injection valve 14, an outer channel 6, an inner channel 8, an inner water suction pump 11 and a bypass valve 12 form a preheating and heat-insulating loop, and the specific water flow direction schematic diagram is shown in figure 2; the heat pump unit 1, the middle layer water injection pump 2, the middle layer passage 7, the inner layer passage 8, the inner layer water suction pump 11 and the inner layer water suction valve 13 form a heating loop, and the specific water flow direction schematic diagram is shown in fig. 3.

Under the working condition of heat storage in summer, the middle-layer water injection pump 2, the middle-layer channel 7, the outer-layer channel 6, the outer-layer water pumping valve 15 and the outer-layer water pumping pump 16 form a heat storage loop, the specific water flow direction schematic diagram is shown in fig. 4, the inner-layer water pumping pump 11 is installed at the front ends of the bypass valve 12 and the inner-layer water pumping valve 13, the outer-layer water pumping valve 15, the water injection valve 14 and the bypass valve 12 can adopt ball valves, electromagnetic valves and the like.

The water injection pump and the water suction pump of the system are both arranged on the ground, and the underground submersible pumps are arranged in the difference with the prior art, so that the initial investment and the energy consumption can be reduced.

Specifically, use summer heat-retaining operating mode and winter heating operating mode as the example, 15 ℃ are got to heat pump set return water temperature, and during the summer heat-retaining, 45 ℃ are got to heat pump set injection temperature, the detailed introduction the utility model discloses a particular embodiment:

in the summer heat storage working condition, the opening and closing conditions of each water pump and each valve are as follows: the working process comprises the steps that hot water in the heat pump unit 1 enters the middle-layer channel 7 through the middle-layer water injection pump 2, the outer-layer water outlet valve 15 is opened, the outer-layer water suction pump 16 is opened, other water pumps and valves are in a closed state, the hot water cannot continuously enter the high-temperature section 9 of the geothermal well to exchange heat under the action of the outer-layer water suction pump 16, the hot water and the low-temperature section 10 of the geothermal well exchange heat in the outer-layer channel 6, heat brought in the hot water is transferred to a rock stratum of the low-temperature section 10 through heat conduction, the heat storage process in summer is achieved, and the water after heat exchange enters the heat pump unit 1 through the outer-layer water suction pump 16 to be circulated again.

In the stage of preheating the heat preservation pipe and forming the heat preservation layer in the water area under the working condition in winter, the opening and closing conditions of each water pump and each valve are as follows: the working process comprises the steps that cold water in the heat pump unit 1 enters the outer layer channel 6 through the outer layer water injection pump 17 and the outer layer water injection valve 14, the cold water conducts heat conduction and heat exchange with the low temperature section 10 of the geothermal well in the outer layer channel 6 firstly, heat stored in the low temperature section 10 of the geothermal well in summer and heat stored in a rock stratum are absorbed, then the cold water continues to conduct heat conduction and heat exchange with the high temperature section 9 of the geothermal well downwards, hot water after heat exchange enters the middle layer channel 7 through the inner layer channel 8 and the bypass valve 12 under the action of the inner layer water suction pump 11, the outer wall of the first layer casing 3 and the inner wall of the second layer casing 4 are preheated in the middle layer channel 7, heat loss is reduced, the water outlet temperature of a wellhead is improved, and the utilization rate of the geothermal water is further improved, after the bypass channel is subjected to a plurality of preheating cycles, the water temperature in the first layer of sleeve 3, the second layer of sleeve 4 and the middle layer of channel 7 rises and keeps basically constant, the inner layer water pumping valve 13 is opened, the bypass valve 12 is closed, and the heating stage under working conditions in winter is started, so that the water in the middle layer of channel 7 is in a surface static state due to the absence of external force, and a stable middle layer heat preservation water area is formed.

In the heating stage under the working condition in winter, the opening and closing conditions of each valve are as follows: the working process is that cold water in the heat pump unit 1 enters an outer layer channel through the outer layer water injection pump 17 and the outer layer water injection valve 14, exchanges heat stored in a rock stratum in summer in the low temperature section 10 of the geothermal well with heat in the rock stratum, continues to conduct heat downwards with the rock stratum outside the high temperature section 9 of the geothermal well under the pushing action of the outer layer water injection pump 17 and the suction action of the inner layer water suction pump 11, high temperature hot water after heat exchange enters the inner layer channel 8, and because a water area heat insulation layer exists in the middle layer channel 7, the high temperature hot water in the inner layer water outlet channel 8 can not directly exchange heat with cold water in the outer layer water inlet channel 6, the heat loss of the high temperature hot water in the inner layer water outlet channel 8 is reduced, and the water outlet temperature is improved, thereby improving the heat taking and utilizing efficiency of the geothermal water.

Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that: various substitutions, changes and modifications are possible without departing from the spirit and scope of the invention and the appended claims, and therefore, the scope of the invention is not limited to the embodiments disclosed.

Claims

1. The utility model provides a heat-retaining formula geothermal energy full-well section dry well heat recovery system, adopts hot heating unit and underground including adopting hot heating unit, adopts hot heating unit to set up subaerial, includes heat pump set, water injection pump and suction pump, its characterized in that: the water injection pump comprises a middle-layer water injection pump and an outer-layer water injection pump, the water suction pump comprises an inner-layer water suction pump and an outer-layer water suction pump, and an inner-layer water suction valve and a bypass valve are mounted at the front end of the inner-layer water suction pump; the underground heat production unit is arranged in an underground well and comprises a central pipe, a sleeve is coaxially sleeved outside the central pipe, the central pipe is inserted into a low-temperature layer and a high-temperature layer which penetrate through the underground well, the sleeve is inserted into the low-temperature layer, and the central pipe, the sleeve and the underground well wall form an outer layer channel, a middle layer channel and an inner layer channel.

2. The heat storage type geothermal energy full-well section dry well heat production system according to claim 1, wherein the heat storage type geothermal energy full-well section dry well heat production system comprises: the heat-storage geothermal energy full-well section dry well heat extraction system comprises a heating loop, a heat storage loop and a preheating heat preservation loop, wherein the heating loop comprises a heat pump unit, a middle-layer water injection pump, a middle-layer channel, an inner-layer water suction pump and an inner-layer water suction valve, the heat storage loop comprises a middle-layer water injection pump, a middle-layer channel, an outer-layer water suction valve and an outer-layer water suction pump, and the preheating heat preservation loop comprises a heat pump unit, an outer-layer water injection pump, an outer-layer water injection valve, an outer-layer channel, an inner-layer water suction pump and a bypass valve.

3. The heat storage type geothermal energy full-well section dry well heat production system according to claim 1, wherein the heat storage type geothermal energy full-well section dry well heat production system comprises: the water injection pump and the water suction pump are both arranged on the ground.