A compressed air energy storage system and control method utilizing heating pipeline gas storage

Abstract

The present invention discloses a compressed air energy storage system and control method for storing gas using a heating pipeline, which relates to the field of carbon emission reduction technology and includes a control system, a heating and gas supply system, a compressor and expander system, and a heat exchange system. The heating and gas supply system includes at least one heating boiler and at least one heat exchange station. The compressor and expander system includes an electric motor, a compressor, an expander, and a generator. The heat exchange system includes a heat exchanger, a cold storage tank, a heat storage tank, and a high-temperature pump. The control system includes a frequency converter, a flow meter, a pressure sensor, and a temperature sensor. The present invention adopts the above-mentioned compressed air energy storage system and control method for storing gas using a heating pipeline, and uses the existing primary heating pipeline network as a gas storage device, which significantly reduces the construction and operation costs of urban compressed air energy storage power stations, and improves the flexibility and response speed of the energy storage system, providing urban users with efficient, economical, and environmentally friendly energy storage solutions, and promoting the solution to the problem of renewable energy absorption.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon emission reduction, and in particular to a compressed air energy storage system and a control method for storing gas in a heating pipeline. Background Art

[0002] As renewable energy consumption becomes increasingly problematic and electricity demand becomes more volatile, user-side commercial and industrial energy storage technology is a key means of addressing the mismatch between energy supply and demand in urban areas. Compressed air energy storage, a promising large-scale power storage technology, can convert electricity into the pressure energy of air and the thermal energy of thermal oil when electricity demand is low, and then convert the internal energy of the working fluid into electricity during peak electricity demand periods. While this technology has been widely adopted, its widespread adoption remains limited, particularly due to the relatively expensive gas storage facilities.

[0003] Existing compressed air energy storage systems can be divided into two types of gas storage methods: underground gas storage (such as salt caverns and mines) and high-pressure gas storage containers (such as steel gas tanks). The main problems with underground gas storage include: high construction costs and difficulty; stringent site selection requirements and numerous geographical constraints; and long development cycles, requiring significant funding and time to complete geological surveys and construction. For surface gas storage facilities, such as high-pressure gas storage containers, the main problem is that high-pressure gas tanks must meet the requirements of high pressure and frequent filling and degassing, placing high demands on material strength and safety, resulting in high construction investment and subsequent maintenance costs. Furthermore, high-pressure gas tanks require a large footprint to store large amounts of compressed air, which places certain restrictions on site selection.

[0004] Whether it's underground gas storage or high-pressure gas tanks, their operation requires significant capital investment. Compressed air energy storage facilities operate under high temperatures and high pressures for extended periods of time, posing significant maintenance costs and safety risks. Regular inspections and maintenance are required, consuming significant manpower and material resources.

[0005] Therefore, the low cost-effectiveness and low flexibility of gas storage facilities have become one of the main obstacles to the popularization and large-scale application of compressed air energy storage technology. To solve this problem, it is urgent to develop new and cost-effective gas storage methods to reduce the construction and operation costs of compressed air energy storage power stations. Summary of the Invention

[0006] The purpose of the present invention is to provide a compressed air energy storage system and control method that utilizes heating pipelines to store gas, so as to solve the problems faced by existing compressed air energy storage technologies in urban applications, especially the high construction cost and insufficient flexibility of gas storage facilities in energy storage systems. By innovatively utilizing the existing primary heating pipeline network as a gas storage device, the construction and operation costs of urban compressed air energy storage power stations are significantly reduced, and the flexibility and response speed of the energy storage system are improved, providing urban users with efficient, economical and environmentally friendly energy storage solutions, and promoting the solution to the problem of renewable energy absorption.

[0007] To achieve the above objectives, the present invention provides a compressed air energy storage system that utilizes heating pipelines to store gas, comprising a control system, a heating and gas supply system, a compressor and expander system, and a heat exchange system. The heating and gas supply system includes at least one heating boiler and at least one heat exchange station. The compressor and expander system includes an electric motor, a compressor, an expander, and a generator. The heat exchange system includes a heat exchanger, a cold storage tank, a heat storage tank, and a high-temperature pump. The heat exchange system, the compressor and expander system, and the heating and gas supply system also include multiple valves, and each system and each system structure is connected by a pipeline.

[0008] The control system includes a frequency converter, a flow meter, a pressure sensor and a temperature sensor. The control system collects the operating data of each system in real time and monitors and adjusts the working status of each system structure.

[0009] Preferably, the heat exchange station is connected to the hot water pipe of the primary pipeline network through the hot water side inlet valve of the heat exchange station, and is connected to the cold water pipe of the primary pipeline network through the cold water side outlet valve of the heat exchange station; the heating boiler is connected to the cold water pipe of the primary pipeline network through the cold water side inlet valve of the heating boiler, and is connected to the hot water pipe of the primary pipeline network through the hot water side outlet valve of the heating boiler.

[0010] Preferably, the electric motor and the generator are connected to the compressor and the expander respectively, the compressor outlet is provided with a compressor outlet stop valve, the expander inlet is provided with an expander inlet stop valve, and the expander and the compressor are both connected to the heating boiler through the atmospheric circulation pipeline, and the atmospheric circulation pipeline is provided with a gas storage regulating valve, a gas storage inlet stop valve and a gas storage bypass stop valve.

[0011] Preferably, the heat storage tank and the cold storage tank are connected via an inlet pipeline and an outlet pipeline, the outlet pipeline is provided with a cold storage tank outlet stop valve and a heat storage tank outlet stop valve, and the inlet pipeline is provided with a heat storage tank inlet stop valve and a cold storage tank inlet stop valve;

[0012] One side of the variable frequency high temperature pump is connected to the outlet pipeline, and the other side of the variable frequency high temperature pump is connected to the heat exchanger inlet regulating valve, and a high temperature pump outlet stop valve is provided between the heat exchanger inlet regulating valve and the variable frequency high temperature pump.

[0013] Preferably, the heat exchanger is connected to the atmospheric circulation pipeline, and one side of the heat exchanger is provided with a heat exchanger cold liquid side inlet stop valve and a heat exchanger cold liquid side outlet stop valve connected in parallel, and the other side is provided with a heat exchanger hot liquid side inlet stop valve and a heat exchanger hot liquid side outlet stop valve connected in parallel, and the heat exchanger hot liquid side outlet stop valve and the heat exchanger cold liquid side outlet stop valve are connected in parallel and connected to the inlet pipeline through a pipeline;

[0014] The heat exchanger cold liquid side inlet stop valve and the heat exchanger hot liquid side inlet stop valve are connected in parallel and are connected to the heat exchanger inlet regulating valve through pipelines.

[0015] Preferably, the frequency converter includes a high-temperature pump frequency converter, a motor frequency converter and a generator frequency converter respectively connected to the variable-frequency high-temperature pump, the motor and the generator.

[0016] Preferably, the flowmeter includes an air flowmeter connected to the atmospheric circulation pipeline and a thermal oil flowmeter connected to the pipeline on one side of the high-temperature variable frequency pump.

[0017] Preferably, the pressure sensor includes a gas storage pressure sensor connected to the atmospheric circulation pipeline and arranged between the gas storage inlet stop valve and the gas storage bypass stop valve.

[0018] Preferably, the temperature sensors include a heat storage tank temperature sensor, a cold storage tank temperature sensor, a heat exchanger thermal oil cold side temperature sensor and a heat exchanger thermal oil hot side temperature sensor respectively connected to the heat storage tank, the cold storage tank and the heat exchanger, and a heat exchanger air hot side temperature sensor and a heat exchanger air cold side temperature sensor connected to the atmospheric circulation pipeline.

[0019] A control method for a compressed air energy storage system utilizing a heating pipeline to store gas comprises the following steps:

[0020] Step S1: Under the control of the control system, the valve openings, the speeds of the compressor and expander, and the speed of the high-temperature pump are adjusted so that during the energy storage process, the motors and compressors in the compressor and expander systems compress the air to a high-temperature and high-pressure state, the heat exchange system transfers the heat energy of the air to the thermal oil, and stores the heat in the heat storage tank, and the normal-temperature and high-pressure air is stored in the heating and gas supply systems through the control system;

[0021] Step S2: During the energy release process, the air in the heating and gas supply system is heated to a high temperature and high pressure state by the heat exchange system, and then the internal energy of the air is converted into electrical energy by the expander and generator in the compressor and expander system.

[0022] Therefore, the present invention adopts the above-mentioned compressed air energy storage system and control method using heating pipelines to store gas, which has the following beneficial effects:

[0023] (1) Fully utilize existing infrastructure and reduce construction costs: This system combines compressed air energy storage with the heating pipeline system, using the existing primary heating pipeline network as a gas storage facility to reduce the construction cost of the compressed air energy storage power station. Currently, the heating pipeline network has covered most of the northern cities in my country. Renovating and upgrading the existing primary heating pipeline network as a compressed air storage device can avoid investing in the construction of new gas storage facilities. At the same time, adding intelligent control equipment can fully improve the operational flexibility of the gas storage device.

[0024] (2) Enhance energy utilization efficiency and achieve energy diversification: This system can coordinate with the heating system to ensure the heating needs of heat users in winter and meet the energy storage needs of urban users during non-heating periods, fully improve the overall utilization rate of the energy system, and achieve diversification of energy supply.

[0025] (3) Promote the widespread application of renewable energy in power systems: This system can combine compressed air energy storage technology with renewable energy power generation. Under the coordinated work of the energy storage control system, monitoring device and control device, it can intelligently control the speed and pressure of the compressor and expander, and has strong adaptability to the intermittent and unstable nature of renewable energy power generation. In addition, this system makes full use of a heat exchange device to realize the functions of cooling the compressor outlet air during the energy storage phase and heating the expander inlet air during the energy release phase. At the same time, under the action of the control system of the present invention, the amount of thermal oil in the heat exchanger is intelligently adjusted, thereby realizing the efficient coupling and decoupling process of pressure energy and thermal energy, and fully improving the adaptability to the volatility of renewable energy (such as wind power generation and solar energy).

[0026] (4) Promote the commercial application of energy storage power stations: This system adopts a lower-cost gas storage method, which improves the economic efficiency of compressed air energy storage technology while reducing the requirements for site selection, thereby promoting the commercial promotion of energy storage power stations. This system uses an efficient and low-cost heat exchange method to accurately match the air heat and the amount of thermal oil, achieving efficient storage and utilization of thermal energy. This intelligent thermal management method improves the overall energy efficiency of the energy storage system and promotes high coordination and efficiency of the energy storage and release processes. At the same time, this system uses a heat exchange device to achieve intelligent thermal management, significantly reducing the construction and operation costs of compressed air energy storage power stations, and further improving the economic efficiency of the energy storage system.

[0027] (5) Improving the flexibility and reliability of user-side energy storage: This system uses a primary heating pipeline network as a gas storage device, making it suitable for urban construction, meeting the diverse energy storage needs of users, and promoting the participation of power users in grid load regulation and demand response. For users who require a stable power supply (such as hospitals and data centers), this system can meet the city grid's emergency backup function in the event of grid failures or fluctuations, ensuring that critical facilities and large-scale events are not affected by power fluctuations and providing high-quality electricity.

[0028] (6) The benefits of this system are not only reflected in the effective expansion of the functions of traditional heating facilities, but also in its ability to deeply meet the diverse needs of urban users for cost-effective, large-scale energy storage technologies, and promote the formation of an efficient, flexible and low-carbon energy storage and supply platform in urban areas.

[0029] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural schematic diagram of an embodiment of a compressed air energy storage system and a control method for storing air using a heating pipeline according to the present invention;

[0031] Figures: 1, electric motor; 2, compressor; 3, compressor outlet stop valve; 4, heat exchanger; 5, gas storage regulating valve; 6, gas storage inlet stop valve; 7, gas storage bypass stop valve; 8, expander inlet stop valve; 9, expander; 10, generator; 11, cold storage tank; 12, cold storage tank outlet stop valve; 13, variable frequency high-temperature pump; 14, high-temperature pump outlet stop valve; 15, heat exchanger inlet regulating valve; 16, heat exchanger cold liquid side inlet stop valve; 17, heat exchanger hot liquid side outlet stop valve; 18, heat storage tank inlet stop valve; 19, heat storage tank; 20, heat storage tank outlet stop valve; 21, heat exchanger hot liquid side inlet stop valve; 22, heat exchanger cold liquid side outlet stop valve; 23, cold storage tank inlet stop valve; 24, air flow meter; 25, heat exchanger air hot side temperature sensor; 26, heat exchanger air cold side temperature sensor; 27. Cold storage tank temperature sensor; 28. Heat storage tank temperature sensor; 29. ​​Heat exchanger thermal oil cold-side temperature sensor; 30. Heat exchanger thermal oil hot-side temperature sensor; 31. Thermal oil flowmeter; 32. Gas storage pressure sensor; 33. High-temperature pump inverter; 34. Motor inverter; 35. Generator inverter; 36. Control system; 37. Heating boiler; 38. Heat exchange station one; 39. Heat exchange station two; 40. Heat exchange station three; 41. Heating boiler hot-water side outlet valve; 42. Heating boiler cold-water side inlet valve; 43. Heat exchange station one hot-water side inlet valve; 44. Heat exchange station one cold-water side outlet valve; 45. Heat exchange station two hot-water side inlet valve; 46. Heat exchange station two cold-water side outlet valve; 47. Heat exchange station three hot-water side inlet valve; 48. Heat exchange station three cold-water side outlet valve; 49. Primary network hot water pipe; 50. Primary network cold water pipe. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0033] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0034] Example

[0035] See also Figure 1 The present invention provides a compressed air energy storage system that utilizes heating pipelines for gas storage, comprising a control system 36, a heating and gas supply system, a compressor 2, an expander 9 system, and a heat exchange system. The heating and gas supply system includes at least one heating boiler 37, at least one heat exchange station, and various on / off valves. The heating and gas supply system refers to the existing primary heating pipeline network in urban areas. In addition to providing heating in winter, it can also serve as a gas storage device for a compressed air energy storage power station during the idle primary period when heating is not in operation. Each of these systems and their structures is connected by pipelines.

[0036] like Figure 1 As shown, the heating and gas supply system demonstrated in this embodiment includes a heating boiler 37 and three heat exchange stations. The specific structure includes the heating boiler 37, heat exchange station 1 38, heat exchange station 2 39, heat exchange station 3 40, the hot water side outlet valve 41 of the heating boiler, the cold water side inlet valve 42 of the heating boiler, the hot water side inlet valve 43 of heat exchange station 1, the cold water side outlet valve 44 of heat exchange station 1, the hot water side inlet valve 45 of heat exchange station 2, the cold water side outlet valve 46 of heat exchange station 2, the hot water side inlet valve 47 of heat exchange station 3, the cold water side outlet valve 48 of heat exchange station 3, the hot water pipe 49 of the primary pipeline network, and the cold water pipe 50 of the primary pipeline network.

[0037] The basic functions of the heating and gas supply systems include heating and gas storage. The heating function refers to the fact that when winter arrives, the primary pipeline network of the heating and gas supply systems ceases to serve as a gas storage facility and only provides hot water transportation. The gas storage function refers to the fact that when not in heating mode, the primary pipeline network of the heating and gas supply systems serves as a gas storage facility, providing gas storage for the compressed air energy storage system. When the heating function is activated, all valves are closed, and the hot water outlet valve 41 of the heating boiler, the cold water inlet valve 42 of the heating boiler, the hot water inlet valve 43 of heat exchange station one, the cold water outlet valve 44 of heat exchange station one, the hot water inlet valve 45 of heat exchange station two, the cold water outlet valve 46 of heat exchange station two, the hot water inlet valve 47 of heat exchange station three, and the cold water outlet valve 48 of heat exchange station three are opened, and the heating boiler 37, heat exchange station one 38, heat exchange station two 39, and heat exchange station three 40 are activated. Hot water flows from the heating boiler 37 along the hot water pipe 49 of the primary pipeline network to heat exchange station 1 38, heat exchange station 2 39 and heat exchange station 3 40; cold water flows from heat exchange station 1 38, heat exchange station 2 39 and heat exchange station 3 40 along the cold water pipe 50 of the primary pipeline network back to the heating boiler 37.

[0038] The compressor 2 and expander 9 system, consisting of the motor 1, compressor 2, expander 9, generator 10, and various on / off valves, is the core component of the compressed air energy storage system, responsible for both air compression and expansion. During the energy storage phase, the compressor 2 system compresses air to a high pressure. During the energy release phase, the expander 9 system expands the stored high-pressure air, releasing the stored energy and driving the generator 10 for power generation.

[0039] like Figure 1 As shown, in this embodiment, the compressor 2 and expander 9 system includes an electric motor 1, a compressor 2, a compressor outlet stop valve 3, a gas storage regulating valve 5, a gas storage inlet stop valve 6, a gas storage bypass stop valve 7, an expander inlet stop valve 8, an expander 9 and a generator 10.

[0040] The basic functions of the compressor 2 and expander 9 system include the compressor 2 function and the expander 9 function. The compressor 2 function refers to the energy storage phase, when compressor 2 operates to compress atmospheric air to a high temperature and high pressure state. The expander 9 function refers to the energy release phase, when expander 9 operates to expand the high temperature and high pressure air, converting the air's internal energy into electrical energy. When the compressor 2 function is activated, all valves are closed, the compressor outlet shut-off valve 3, the gas storage regulating valve 5, the gas storage inlet shut-off valve 6, and the gas storage bypass shut-off valve 7 are opened, the air supply function of the heating and gas supply system is activated, and the motor 1 and compressor 2 are started. During energy storage, motor 1 drives compressor 2 to perform work, compressing air from the atmosphere to a high temperature and high pressure state. The high temperature and high pressure air enters the heat exchanger 4 through the compressor outlet shut-off valve 3, cools to room temperature, and then enters the heating and gas supply system through the gas storage regulating valve 5, the gas storage inlet shut-off valve 6, and the gas storage bypass shut-off valve 7. When expander 9 is activated, all valves are closed, the gas storage bypass shutoff valve 7, gas storage inlet shutoff valve 6, gas storage regulating valve 5, and expander inlet shutoff valve 8 are opened, the heating and gas supply system's gas supply function is turned on, and expander 9 and generator 10 are started. During energy release, high-pressure air is released from the heating and gas supply system, passes through the gas storage bypass shutoff valve 7, gas storage inlet shutoff valve 6, and gas storage regulating valve 5, enters the heat exchanger 4, is heated to a high temperature, and passes through the expander inlet shutoff valve 8. The air's internal energy is converted into mechanical energy within expander 9, which is then converted into electrical energy by generator 10. Simultaneously, the low-pressure air is discharged into the atmosphere.

[0041] The heat exchange system includes a heat exchanger 4, a cold storage tank 11, a heat storage tank 19, a variable-frequency high-temperature pump 13, and various on / off valves. The heat storage medium is thermal oil. The heat exchange system primarily separates and stores heat from the air at the outlet of compressor 2 during energy storage, and provides heat to the inlet of expander 9 during energy release. During the energy storage phase, ambient temperature thermal oil flows from the cold storage tank 11, enters the variable-frequency high-temperature pump 13 for pressure increase, and then enters the heat exchanger 4. The high-temperature, high-pressure air in the heat exchanger 4 transfers heat to the thermal oil. After the oil heats up, it enters the heat storage tank 19 to store heat, achieving a separation of thermal energy and pressure energy. During the energy release phase, the high-temperature thermal oil flows from the heat storage tank 19, enters the variable-frequency high-temperature pump 13 for pressure increase, enters the heat exchanger 4, transfers heat to the ambient temperature, high-pressure air, and then returns to the cold storage tank 11. This improves the efficiency of the expander 9, ensures efficient energy utilization, and reduces energy loss.

[0042] like Figure 1As shown, in this embodiment, the heat exchange system specifically includes a heat exchanger 4, a cold storage tank 11, a cold storage tank outlet stop valve 12, a variable frequency high-temperature pump 13, a high-temperature pump outlet stop valve 14, a heat exchanger inlet regulating valve 15, a heat exchanger cold liquid side inlet stop valve 16, a heat exchanger hot liquid side outlet stop valve 17, a heat storage tank inlet stop valve 18, a heat storage tank 19, a heat storage tank outlet stop valve 20, a heat exchanger hot liquid side inlet stop valve 21, a heat exchanger cold liquid side outlet stop valve 22, and a cold storage tank inlet stop valve 23. The heat storage medium in the heat exchange system is thermal oil.

[0043] The main purpose of the heat exchange system is to separate and store heat from the air at the outlet of compressor 2 during energy storage and to provide heat to the inlet of expander 9 during energy release. Specifically, during energy storage, all valves in the heat exchange system remain closed. The cold storage tank outlet shutoff valve 12, high-temperature pump outlet shutoff valve 14, heat exchanger inlet regulating valve 15, heat exchanger cold liquid inlet shutoff valve 16, heat exchanger hot liquid outlet shutoff valve 17, and heat storage tank inlet shutoff valve 18 are opened, and the variable-frequency high-temperature pump 13 is activated. Ambient-temperature thermal oil flows from the cold storage tank 11 through the cold storage tank outlet shutoff valve 12, enters the variable-frequency high-temperature pump 13 for pressure boost, and then passes through the high-temperature pump outlet shutoff valve 14, heat exchanger inlet regulating valve 15, and heat exchanger cold liquid inlet shutoff valve 16 before entering the cooling liquid inlet of the heat exchanger. The high-temperature air transfers heat to the thermal oil within the heat exchanger, causing the oil to heat up. The hot oil then passes through the heat exchanger hot liquid outlet shutoff valve 17 and the heat storage tank inlet shutoff valve 18 before entering the heat storage tank 19. During energy release, all valves in the heat exchange system remain closed. The heat storage tank outlet shutoff valve 20, high-temperature pump outlet shutoff valve 14, heat exchanger inlet regulating valve 15, heat exchanger hot liquid side inlet shutoff valve 21, heat exchanger cold liquid side outlet shutoff valve 22, and cold storage tank inlet shutoff valve 23 are opened, and the variable frequency high-temperature pump 13 is started. High-temperature thermal oil flows from the heat storage tank 19 through the heat storage tank outlet shutoff valve 20 and into the variable frequency high-temperature pump 13. The pressurized high-temperature thermal oil then passes through the high-temperature pump outlet shutoff valve 14, the heat exchanger inlet regulating valve 15, and the heat exchanger hot liquid side inlet shutoff valve 21, entering the high-temperature liquid inlet side of heat exchanger 4. After transferring heat to the air, the cooled thermal oil returns to the cold storage tank 11 through the heat exchanger cold liquid side outlet shutoff valve 22 and the cold storage tank inlet shutoff valve 23.

[0044] Control system 36 includes a frequency converter, flowmeter, pressure sensor, and temperature sensor. It collects real-time operating data from each system, monitors, and adjusts the operating status of each system structure. By collecting real-time operating data from each component, control system 36 precisely adjusts the operating conditions of compressor 2 and expander 9, thereby optimizing parameters such as flow rate, pressure, and temperature during the energy storage and release processes. Control system 36 also includes functions such as regulating the gas storage vessel pressure and gas storage temperature, enabling automatic adjustments based on energy demand and system operating conditions to achieve optimal energy storage and release efficiency.

[0045] like Figure 1 As shown, in this embodiment, the control system 36 specifically includes a variable frequency high-temperature pump inverter 33, a motor inverter 34, a generator inverter 35, an air flow meter 24, a heat exchanger air hot side temperature sensor 25, a heat exchanger air cold side temperature sensor 26, a cold storage tank temperature sensor 27, a heat storage tank temperature sensor 28, a heat exchanger thermal oil cold side temperature sensor 29, a heat exchanger thermal oil hot side temperature sensor 30, a thermal oil flow meter 31, a gas storage pressure sensor 32 and a control system 36.

[0046] The functions of the control system 36 include adjusting the speed of the motor 1, adjusting the speed of the generator 10, adjusting the flow rate of the thermal oil, and adjusting the gas storage pressure. The purpose of adjusting the speed of the motor 1 is to be able to maintain and adjust the speed of the motor 1 according to the input power of different frequencies, so that the compressor 2 can meet the energy supply of various renewable energy sources and maintain a high working efficiency. The implementation process is that the control system 36 measures the frequency of the input power and the performance curve of the compressor 2, adjusts the output frequency of the inverter, and thus adjusts the speed of the motor 1 and the compressor 2. The purpose of adjusting the speed of the generator 10 is to be able to adjust the speed of the expander 9 according to the gas storage pressure in the heating and gas supply system so that it operates at the optimal efficiency state, and at the same time adjust the frequency of the power provided by the generator 10 to meet the frequency requirements of the power grid. The implementation process is that the control system 36 adjusts the frequency of the generator inverter 35 and the speed of the expander 9 according to the pressure displayed by the gas storage pressure sensor 32 and the performance curve of the expander 9 so that it operates at the optimal performance condition, while ensuring that the output power frequency meets the requirements of the power grid.

[0047] The thermal oil flow adjustment function refers to the ability of the present invention to adjust the thermal oil flow rate in real time based on the compressor 2 outlet temperature and the stored air temperature, thereby reducing energy storage heat loss. Specifically, during energy storage, the opening of the heat exchanger inlet regulating valve 15 and the speed of the variable frequency high-temperature pump 13 are adjusted based on the air temperatures displayed by the heat exchanger's cold-side air temperature sensor 26 and the heat exchanger's hot-side air temperature sensor 25. For example, during energy storage, when the air temperature displayed by the heat exchanger air cold side temperature sensor 26 is too high, the opening of the heat exchanger inlet regulating valve 15 is increased, and the frequency of the variable frequency high temperature pump inverter 33 and the speed of the variable frequency high temperature pump 13 are adjusted, thereby increasing the flow of thermal oil flowing out of the cold storage tank 11 into the heat exchanger 4 and lowering the air temperature; when the air temperature displayed by the heat exchanger air cold side temperature sensor 26 is too low, the opening of the heat exchanger inlet regulating valve 15 is reduced, and the frequency of the variable frequency high temperature pump inverter 33 and the speed of the variable frequency high temperature pump 13 are adjusted, thereby reducing the flow of thermal oil flowing out of the cold storage tank 11 into the heat exchanger 4 and raising the air temperature. During energy release, when the air temperature displayed by the heat exchanger air hot side temperature sensor 25 is too low, the opening of the heat exchanger inlet regulating valve 15 is increased, and the frequency of the variable frequency high temperature pump inverter 33 and the speed of the variable frequency high temperature pump 13 are adjusted, thereby increasing the flow of heat transfer oil flowing out of the heat storage tank 19 into the heat exchanger 4 and improving the air temperature entering the expander 9; when the air temperature displayed by the heat exchanger air hot side temperature sensor 25 is too high, the opening of the heat exchanger inlet regulating valve 15 is reduced, and the frequency of the variable frequency high temperature pump inverter 33 and the speed of the variable frequency high temperature pump 13 are adjusted, thereby reducing the flow of heat transfer oil flowing out of the heat storage tank 19 into the heat exchanger 4 and reducing the air temperature entering the expander 9.

[0048] The control method of the compressed air energy storage system using the heating pipeline to store gas comprises the following steps:

[0049] Step S1: Under the control of the control system 36, the valve openings, the speeds of the compressor 2 and the expander 9, and the speed of the variable frequency high-temperature pump 13 are adjusted so that during the energy storage process, the motor 1 and the compressor 2 in the compressor 2 and expander 9 systems compress the air to a high-temperature and high-pressure state, the heat exchange system transfers the heat energy of the air to the thermal oil, and stores the heat in the heat storage tank 19, and the normal-temperature and high-pressure air is stored in the heating and gas supply system through the control system 36;

[0050] In step S2, during the energy release process, the air in the heating and gas supply system is heated to a high temperature and high pressure state through the heat exchange system, and then the internal energy of the air is converted into electrical energy through the expander 9 and the generator 10 in the compressor 2 and expander 9 system.

[0051] Therefore, the present invention adopts the above-mentioned compressed air energy storage system and control method that uses heating pipelines to store gas, and uses the existing primary heating pipeline network as a gas storage device, which significantly reduces the construction and operation costs of urban compressed air energy storage power stations, and improves the flexibility and response speed of the energy storage system, providing urban users with efficient, economical and environmentally friendly energy storage solutions, and promoting the solution to the problem of renewable energy absorption.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A compressed air energy storage system utilizing heating pipelines to store gas, characterized by: It includes a control system, a heating and gas supply system, a compressor and expander system, and a heat exchange system. The heating and gas supply system includes at least one heating boiler and at least one heat exchange station. The compressor and expander system includes an electric motor, a compressor, an expander, and a generator. The heat exchange system includes a heat exchanger, a cold storage tank, a heat storage tank, and a high-temperature pump. The heat exchange system, the compressor and expander system, and the heating and gas supply system also include multiple valves. The systems and system structures are connected by pipelines. The control system includes a frequency converter, flow meter, pressure sensor and temperature sensor. The control system collects the operating data of each system in real time and monitors and adjusts the working status of each system structure; Normal temperature and high pressure air is stored in the heating and air supply system through the control system.

2. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 1, characterized in that: The heat exchange station is connected to the hot water pipe of the primary pipeline network through the hot water side inlet valve of the heat exchange station, and is connected to the cold water pipe of the primary pipeline network through the cold water side outlet valve of the heat exchange station; the heating boiler is connected to the cold water pipe of the primary pipeline network through the cold water side inlet valve of the heating boiler, and is connected to the hot water pipe of the primary pipeline network through the hot water side outlet valve of the heating boiler.

3. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 2, characterized in that: The electric motor and the generator are connected to the compressor and the expander respectively. The compressor outlet is provided with a compressor outlet stop valve, and the expander inlet is provided with an expander inlet stop valve. The expander and the compressor are both connected to the heating boiler through the atmospheric circulation pipeline. The atmospheric circulation pipeline is provided with a gas storage regulating valve, a gas storage inlet stop valve and a gas storage bypass stop valve.

4. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 3, characterized in that: The heat storage tank and the cold storage tank are connected through an inlet pipe and an outlet pipe. The outlet pipe is provided with a cold storage tank outlet stop valve and a heat storage tank outlet stop valve, and the inlet pipe is provided with a heat storage tank inlet stop valve and a cold storage tank inlet stop valve; One side of the variable frequency high temperature pump is connected to the outlet pipeline, and the other side of the variable frequency high temperature pump is connected to the heat exchanger inlet regulating valve, and a high temperature pump outlet stop valve is provided between the heat exchanger inlet regulating valve and the variable frequency high temperature pump.

5. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 4, characterized in that: The heat exchanger is connected to the atmospheric circulation pipeline. One side of the heat exchanger is provided with a heat exchanger cold liquid side inlet stop valve and a heat exchanger cold liquid side outlet stop valve connected in parallel. The other side is provided with a heat exchanger hot liquid side inlet stop valve and a heat exchanger hot liquid side outlet stop valve connected in parallel. The heat exchanger hot liquid side outlet stop valve and the heat exchanger cold liquid side outlet stop valve are connected in parallel and connected to the inlet pipeline through a pipeline. The heat exchanger cold liquid side inlet stop valve and the heat exchanger hot liquid side inlet stop valve are connected in parallel and are connected to the heat exchanger inlet regulating valve through a pipeline.

6. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 5, characterized in that: The frequency converter includes a high temperature pump frequency converter, a motor frequency converter and a generator frequency converter which are respectively connected to the variable frequency high temperature pump, the motor and the generator.

7. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 6, characterized in that: The flowmeter includes an air flowmeter connected to the atmospheric circulation pipeline and a thermal oil flowmeter connected to the pipeline on one side of the high-temperature variable frequency pump.

8. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 7, characterized in that: The pressure sensor includes a gas storage pressure sensor connected to the atmospheric circulation pipeline and is arranged between the gas storage inlet stop valve and the gas storage bypass stop valve.

9. The compressed air energy storage system utilizing heating pipeline gas storage according to claim 8, characterized in that: The temperature sensors include a heat storage tank temperature sensor, a cold storage tank temperature sensor, a heat exchanger thermal oil cold side temperature sensor and a heat exchanger thermal oil hot side temperature sensor, which are respectively connected to the heat storage tank, the cold storage tank and the heat exchanger, as well as a heat exchanger air hot side temperature sensor and a heat exchanger air cold side temperature sensor connected to the atmospheric circulation pipeline.

10. A control method for a compressed air energy storage system utilizing heating pipeline gas storage according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1: Under the control of the control system, the valve openings, the speeds of the compressor and expander, and the speed of the high-temperature pump are adjusted so that during the energy storage process, the motors and compressors in the compressor and expander systems compress the air to a high-temperature and high-pressure state, and the heat exchange system transfers the heat energy of the air to the thermal oil, which is then stored in the heat storage tank. Step S2: During the energy release process, the air in the heating and gas supply system is heated to a high temperature and high pressure state by the heat exchange system, and then the internal energy of the air is converted into electrical energy by the expander and generator in the compressor and expander system.

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