CN-122015161-A - Source-charge-storage coupling deep geothermal long-time energy storage system and control method

CN122015161ACN 122015161 ACN122015161 ACN 122015161ACN-122015161-A

Abstract

The invention discloses a source-charge storage coupling deep geothermal long-term energy storage system and a control method, belonging to the technical field of geothermal energy storage, the system of the invention consists of a deep heat storage and cogeneration unit, a heat supply plate heat exchange unit, a heat storage plate heat exchange unit, a power grid, a heat supply network and a valve group, and flexible linkage of each unit is realized through the valve group. The control method of the invention is based on the principles of dynamic synergy of source load and storage and ground underground coupling, takes real-time electric heating load of a building as a demand standard, makes a variable working condition operation strategy according to heating seasons of Ji Yufei, realizes alternate operation of heat storage at daytime and heat extraction at night in heating seasons, and controls pure condensation power generation of the cogeneration unit in non-heating seasons and operation of a deep heat storage well. The invention can improve the energy storage efficiency of the system, reduce the heat plume diffusion and heat breakthrough risks, reduce the running cost of the system and shorten the initial investment recovery period.

Inventors

YE CANTAO
LI LENGXUE
LU ZHENNENG
YAO YUAN
Wen Qihang
GONG YULIE

Assignees

中国科学院广州能源研究所

Dates

Publication Date: 20260512
Application Date: 20260312

Claims (10)

1. A source-to-charge coupled deep geothermal long term energy storage system, comprising: The heat and power generation system comprises a deep heat storage unit, a cogeneration unit, a heat supply plate exchange unit, a heat storage plate exchange unit, a power grid unit, a heat supply network unit and a valve set, wherein the cogeneration unit is used for outputting electric energy and heat energy, the cogeneration unit is in bidirectional electric connection with the power grid unit, a steam outlet and a return water inlet of the cogeneration unit are respectively connected with a primary side of the heat supply plate exchange and a primary side pipeline of the heat storage plate exchange through the valve set, the deep heat storage unit is used for storing and releasing geothermal heat energy, the deep heat storage unit is connected with a secondary side pipeline of the heat storage plate exchange through the valve set, the heat supply network unit comprises a water supply network and a return water network, the return water network is respectively connected with a secondary side of the heat supply plate exchange and a secondary side outlet pipeline of the heat storage plate exchange through the valve set, and the valve set is used for controlling on-off flow direction of each pipeline and is respectively correspondingly installed on each valve set.
2. The source-charge coupled deep geothermal long term energy storage system of claim 1, wherein the deep thermal storage unit comprises: The device comprises a cold well, a hot well, a cold well water pump and a hot well water pump, wherein the cold well water pump is arranged in the cold well, the hot well water pump is arranged in the hot well, a water outlet of the cold well water pump is connected with a secondary side inlet pipeline of heat storage plate heat exchange through a twelfth valve, a secondary side outlet of heat storage plate heat exchange is connected with an inlet pipeline of the hot well through an eleventh valve, a water outlet of the hot well water pump is connected with a secondary side inlet pipeline of heat storage plate heat exchange through an eleventh valve, and a secondary side outlet of heat storage plate heat exchange is connected with an inlet pipeline of the cold well through a twelfth valve.
3. The source-charge coupled deep geothermal long term energy storage system of claim 1, wherein the valve set comprises: The heat and power cogeneration system comprises a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, an eighth valve, a ninth valve, a tenth valve, an eleventh valve, a twelfth valve, a thirteenth valve and a fourteenth valve, wherein the first valve is connected in series on a pipeline between a primary heat exchange side outlet of the heat and power cogeneration unit and a return water inlet pipeline of the heat and power cogeneration unit, the third valve is connected in series on a pipeline between the first valve and a primary heat exchange side inlet of the heat supply plate, the fourth valve is connected in series on a pipeline between a primary heat exchange side outlet of the heat supply plate and the second valve, the seventh valve is connected in series on a pipeline between a primary heat exchange side outlet of the heat storage plate and the second valve, the ninth valve is connected in series on a pipeline between a primary heat exchange side outlet of the heat supply plate and a primary heat storage plate and a secondary heat exchange side inlet pipeline, the seventh valve is connected in series on a pipeline between a secondary heat exchange side outlet of the heat storage plate and a heat exchange side inlet pipeline of the heat storage plate, the thirteenth valve is connected in series on a pipeline between a secondary heat exchange side outlet of the heat storage plate and a heat exchange side inlet pipeline of the heat storage plate and a heat storage plate.
4. The source-charge-coupled deep geothermal long-term energy storage system of claim 1, wherein the cogeneration unit is a coal-fired cogeneration unit, the cogeneration unit adopts a condensed gas-heating medium pressure cylinder steam exhaust heat supply mode, and a steam extraction outlet of the cogeneration unit is connected with an inlet pipeline of the first valve.
5. A method for controlling a source-charge-coupled deep geothermal long-term energy storage system, which is applicable to the system of any one of claims 1 to 4, and is characterized by comprising the following steps: Calculating the collected building environment parameters and system operation parameters to obtain building real-time electric heating load data; dividing the operation time period of heating Ji Yufei in a heating season according to the real-time electric heating load data of the building, and generating a variable working condition operation strategy of the corresponding time period; According to the variable working condition operation strategy, high-load variable working condition adjustment is carried out on the cogeneration unit in the daytime heat storage period in a heating season, and heat storage control operation is carried out on deep heat storage; According to the variable working condition operation strategy, low-load variable working condition adjustment is carried out on the cogeneration unit in a heating period at night, and heating control operation is carried out on deep heat storage; switching the cogeneration unit to a pure condensation operation mode in a non-heating season according to the variable working condition operation strategy, and executing well closing control operation on deep heat storage; And (3) utilizing a multi-module dynamic iterative coupling method to adjust the operation parameters of the system equipment and the opening degree of the valve group in real time, so as to complete the cooperative control of the source and the storage.
6. The method of claim 5, wherein the calculating the collected building environment parameters and system operation parameters to obtain building real-time electric heating load data comprises constructing a building dynamic load model by adopting a 5 thermal resistance 1 heat capacity lumped parameter method, discretizing time by adopting an explicit Euler method, solving the building dynamic load model by utilizing a fourth-order Dragon-Gregory tower method, and outputting building real-time heat load and electric load data.
7. The method of claim 5, wherein the performing the heat storage control operation on the deep heat storage by performing the high load variable condition adjustment on the cogeneration unit during the daytime heat storage period in the heating season comprises opening a cold well water pump and closing a hot well water pump to exchange with a heating plate, opening a corresponding valve group to connect with a heat storage runner, constructing a variable condition mathematical model describing the coupling relation of electrothermal fuel, solving the balance constraint of the power grid by using a sequential quadratic programming algorithm, dynamically adjusting the air extraction rate and the load rate of the cogeneration unit, and completing the heat exchange between the cogeneration unit and the deep heat storage by exchanging with the heat storage plate to realize the heat storage operation of the deep heat storage.
8. The method of claim 5, wherein the low-load variable-duty adjustment is performed on the cogeneration unit during the night heating period in the heating season, the performing of the heat extraction and supply operation on the deep heat storage comprises opening a hot well water pump and a heat supply plate, closing a cold well water pump, opening a corresponding valve group to connect a heat extraction and supply runner, performing discretization on a reservoir space of the coupling model by adopting a limited volume method, completing discretization of a time dimension by adopting an explicit Euler method, solving the discretized coupling model time by time, dynamically adjusting the heat extraction power of the deep heat storage, completing heat exchange of the deep heat storage and return water of the heat supply network by using the heat storage plate, and performing secondary temperature rise on the return water of the heat supply network by using the heat supply plate, and then conveying the return water to a building end to realize the heat extraction and supply operation of the deep heat storage.
9. The method of claim 5, wherein switching the cogeneration unit to the pure condensing mode of operation during non-heating season, performing a well shut-in control operation on the deep thermal storage comprises adjusting the cogeneration unit to the pure condensing mode of operation for full power generation, switching off the cold well suction pump, the hot well suction pump, the heat transfer plate, and the heat storage plate, switching off all valves of the valve set to shut off the surface and subsurface hydrothermal flow paths, and keeping the reservoir temperature field stable throughout the well shut-in of the deep thermal storage.
10. The method of claim 5, wherein the real-time adjustment of the system equipment operation parameters and the valve group opening by using the multi-module dynamic iterative coupling method comprises respectively solving a variable working condition model of the cogeneration unit, a dynamic load model of a building and a deep heat Chu Shenliu heat transfer coupling model, feeding back and iterating the solving results of the models to each other until the temperature, flow and power errors of adjacent iteration steps meet preset thresholds, and automatically adjusting the equipment operation parameters and the valve group opening according to the iterating results and monitoring data.

Description

Source-charge-storage coupling deep geothermal long-time energy storage system and control method Technical Field The invention belongs to the technical field of geothermal energy storage and clean energy heating, and particularly relates to the field of operation regulation and control of a deep geothermal long-term energy storage system and a cogeneration coupling building heating system. Background Under the promotion of a double-carbon strategy, the double requirements of clean heating and high-proportion renewable energy consumption in China are continuously upgraded, and a large-scale clean heating system faces the contradiction of energy supply and demand space-time mismatch. On one hand, wind power and photovoltaic renewable energy sources have intermittent fluctuation characteristics, and the problem of power failure restricts the large-scale grid connection of the renewable energy sources. On the other hand, the building heating and refrigerating load shows obvious seasonal period fluctuation, and the traditional heat and power cogeneration unit is difficult to consider the power supply reliability and the heat supply flexibility in a heat and power setting operation mode. The deep geothermal long-time energy storage technology is more suitable for the energy buffering requirement of large-scale cross seasons compared with the conventional water heat storage technology by virtue of the natural advantages of high reservoir temperature, large output and stability, and becomes an important technical scheme for solving the supply and demand mismatch of a clean heating system. At present, scholars at home and abroad develop a large number of numerical simulation researches around a deep geothermal energy storage system, single physical field simulation of focusing underground thermal storage is studied early, and subsequent step-by-step attempts are made to perform association analysis on a ground system and the underground thermal storage, but the prior art still has obvious limitations. Most of the technologies adopt an operation mode of decoupling ground heat source building load and underground heat storage, so that dynamic feedback of variable working conditions of the heat source fluctuation cogeneration unit to the evolution of an underground heat storage temperature field is ignored, and the dynamic characteristics of system operation cannot be truly reflected. The prior art simplifies the heat-collecting recharging temperature of the heat storage heat source temperature into a constant value, does not consider the heat storage temperature fluctuation caused by the adjustment of the air extraction rate of the cogeneration unit, and the heat-collecting recharging temperature change caused by the dynamic load of the building, and has poor matching property with the actual load demand. The prior art generally adopts a fixed mode of continuous heat taking in a heating season and continuous heat storage in a non-heating season, the heat storage period is long, the heat attenuation is serious, the excessive diffusion of heating plumes is easy to cause, and even the heat breakthrough risk occurs. Meanwhile, the prior art scheme causes higher system operation cost, lower energy storage efficiency and long initial investment recovery period due to unreasonable heat loss of heat storage, and restricts the large-scale application of the technology. The existing deep geothermal energy storage system and control method cannot realize full-chain dynamic coordination of heat source load heat storage, and are difficult to adapt to variable working condition requirements of large-scale clean heating. Disclosure of Invention The invention aims to provide a source-charge-storage coupling deep geothermal long-term energy storage system and a control method thereof, which are used for solving the problems of low energy storage efficiency and overlarge thermal plume diffusion range caused by decoupling of the ground and underground and simplified operation modes of the conventional deep geothermal energy storage system and simultaneously relieving the situation of energy supply and demand space-time mismatch of a clean heating system. In order to achieve the above purpose, the present invention provides the following technical solutions: in a first aspect, the present invention provides a source-to-charge coupled deep geothermal long term energy storage system comprising: The heat and power generation system comprises a deep heat storage unit, a cogeneration unit, a heat supply plate exchange unit, a heat storage plate exchange unit, a power grid unit, a heat supply network unit and a valve set, wherein the cogeneration unit is used for outputting electric energy and heat energy, the cogeneration unit is in bidirectional electric connection with the power grid unit, a steam outlet and a return water inlet of the cogeneration unit are respectively connected with a primary side of the heat supply plate exchange and a