Fuel gas and terrestrial heat complementary comprehensive energy supply system coupled with cross-seasonal heat storage and operation method

Abstract

The invention relates to the technical field of distributed energy supply and renewable energy utilization, and provides a fuel gas and terrestrial heat complementary comprehensive energy supply system coupled with cross-seasonal heat storage and an operation method of the fuel gas and terrestrial heat complementary comprehensive energy supply system coupled with cross-seasonal heat storage. Comprising a gas generator set, a waste heat lithium bromide set, a cross-seasonal heat storage subsystem and a ground source heat pump system. According to the system, more comprehensive waste heat resource utilization of the gas generator set is achieved, and the total heat efficiency of the system can be improved; the problem of space-time mismatch between continuous heat production of a gas generator set and seasonal heat supply requirements of a building is solved, heat recycled in a transition season and under a low-load working condition is stored to be used in winter or in a heat consumption peak, cross-seasonal scheduling of energy is achieved, the waste heat utilization efficiency is improved, the operation cost is reduced, and the energy utilization efficiency is also improved.

Description

Technical Field

[0001] This invention relates to the field of distributed energy supply and renewable energy utilization technology, specifically to a gas and geothermal complementary integrated energy supply system coupled with cross-seasonal thermal storage and its operation method. Background Technology

[0002] With the promotion of new energy systems and clean energy, distributed energy systems have been widely applied. Gas-fired distributed energy systems, due to their high energy efficiency and low environmental pollution, are widely used in commercial buildings and industrial parks in China. The prime movers for gas-fired distributed energy systems are typically gas internal combustion engines and gas turbines. Among these, gas-fired distributed energy systems using internal combustion engines as prime movers are often used in large commercial office parks, schools, hospitals, and other clustered building scenarios.

[0003] However, these user scenarios exhibit significant seasonality in energy demand and large load fluctuations. Gas-fired internal combustion engine power generation systems generate substantial amounts of high-temperature waste heat during operation, leading to a mismatch between the generated waste heat resources and user demand in terms of time and space. Furthermore, to meet peak load demands, the system is often designed with unit capacity configured for maximum load. During transitional seasons, when load demand is low or nonexistent, the system frequently suffers from underutilization, resulting in low system utilization throughout the year and high operating costs, thus failing to guarantee project profitability. Summary of the Invention

[0004] Therefore, this invention aims to address the problems in existing gas-fired distributed energy systems, which generate a large amount of high-temperature waste heat during operation. These waste heat resources generally suffer from time and space mismatch with user needs, low system utilization, and high operating costs. The invention provides a gas-fired and geothermal complementary integrated energy supply system and its operation method that couples cross-seasonal heat storage.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: On one hand, the present invention provides a gas and geothermal complementary integrated energy supply system coupled with interseasonal thermal storage, comprising: a gas generator set; a waste heat lithium bromide generator set connected to the gas generator set, wherein the waste heat lithium bromide generator set utilizes a portion of the waste heat from the gas generator set to provide heating and cooling services to users; an interseasonal thermal storage subsystem connected to the gas generator set, wherein the interseasonal thermal storage subsystem is used to recover and store another portion of the waste heat from the gas generator set; and a ground source heat pump system connected to the interseasonal thermal storage subsystem, wherein the ground source heat pump system utilizes the waste heat stored in the interseasonal thermal storage subsystem to provide heating and cooling services to users.

[0006] Furthermore, the waste heat lithium bromide unit utilizes the waste heat from the high-temperature cylinder liner water and high-temperature flue gas of the gas generator set to provide heating and cooling services to users; the cross-seasonal heat storage subsystem recovers the waste heat from the high-temperature cylinder liner water and intermediate cooling water of the gas generator set.

[0007] Furthermore, the integrated gas and geothermal energy supply system coupled with interseasonal thermal storage also includes a first heat dissipation device connected to the high-temperature cylinder liner water circuit of the gas generator set; the waste heat of the high-temperature cylinder liner water of the gas generator set is preferentially utilized through the waste heat lithium bromide unit; when the temperature of the cylinder liner water discharged from the waste heat lithium bromide unit is higher than a first target value, the waste heat of the high-temperature cylinder liner water of the gas generator set is simultaneously recovered using the interseasonal thermal storage subsystem; when the return water temperature of the high-temperature cylinder liner water of the gas generator set is higher than a second target value, the high-temperature cylinder liner water of the gas generator set is cooled by the first heat dissipation device.

[0008] Furthermore, the integrated gas and geothermal energy supply system coupled with interseasonal thermal storage also includes a second heat dissipation device connected to the intermediate cooling water circuit of the gas generator set; the waste heat of the intermediate cooling water of the gas generator set is preferentially recovered by the interseasonal thermal storage subsystem; when the return water temperature of the intermediate cooling water of the gas generator set is higher than the target value, the intermediate cooling water of the gas generator set is cooled by the second heat dissipation device.

[0009] Furthermore, the waste heat in the high-temperature flue gas of the gas generator set is utilized by the waste heat lithium bromide unit to become low-temperature flue gas, and the cross-seasonal heat storage subsystem recovers the waste heat in the low-temperature flue gas.

[0010] Furthermore, this integrated gas and geothermal energy supply system coupled with interseasonal thermal storage also includes a low-temperature flue gas heat exchanger and a hot water storage tank. The low-temperature flue gas heat exchanger is connected to the flue gas outlet pipeline of the waste heat lithium bromide generator unit. The hot water storage tank is connected to the low-temperature flue gas heat exchanger and the interseasonal thermal storage subsystem. The high-temperature flue gas discharged from the gas generator unit is preferentially fed into the waste heat lithium bromide generator unit for utilization, and the low-temperature flue gas discharged from the waste heat lithium bromide generator unit enters the low-temperature flue gas heat exchanger for heat recovery. The hot water generated after the low-temperature flue gas heat exchanger recovers heat is preferentially fed into the hot water storage tank to meet user needs. When the external heat load demand is low or during non-heating conditions, the heat in the hot water generated by the low-temperature flue gas heat exchanger is recovered through the interseasonal thermal storage subsystem.

[0011] Furthermore, the cross-seasonal thermal storage subsystem includes buried thermal storage coils in Zone A, Zone B, and Zone C; the buried thermal storage coil in Zone A is used to store the waste heat of high-temperature cylinder liner water; the buried thermal storage coil in Zone B is used to store the waste heat of low-temperature flue gas; the buried thermal storage coil in Zone C is used to store the waste heat of intermediate-cooled water; and the buried thermal storage coils in Zones A, B, and C are all connected to the ground source heat pump system.

[0012] Furthermore, the thermal storage underground coils in Zone A, Zone B, and Zone C are arranged in concentric circles or concentric rectangles, and are arranged sequentially from the inside to the outside.

[0013] On the other hand, the present invention also provides an operation method for a gas and geothermal complementary integrated energy supply system coupled with inter-seasonal thermal storage, comprising the following steps: using the waste heat in the cylinder liner water and high-temperature flue gas of the gas generator set through a waste heat lithium bromide generator unit to provide heating and cooling services to users; recovering the cylinder liner water, intermediate cooling water, and waste heat in the low-temperature flue gas of the gas generator set after being utilized by the waste heat lithium bromide generator unit through an inter-seasonal thermal storage subsystem; and using the heat stored in the inter-seasonal thermal storage subsystem through a ground source heat pump system to provide heating and cooling services to users.

[0014] Furthermore, when recovering and utilizing the heat from the cylinder liner water of the gas generator set, the specific steps include: preferentially utilizing the waste heat of the high-temperature cylinder liner water of the gas generator set through a waste heat lithium bromide unit; when the temperature of the cylinder liner water discharged from the waste heat lithium bromide unit is higher than a first target value, simultaneously utilizing the inter-seasonal heat storage subsystem to recover the waste heat of the high-temperature cylinder liner water of the gas generator set; when the return water temperature of the high-temperature cylinder liner water of the gas generator set is higher than a second target value, cooling the high-temperature cylinder liner water of the gas generator set is performed through a first cooling device; when recovering and utilizing the heat from the intermediate cooling water of the gas generator set, the specific steps include: preferentially utilizing the inter-seasonal heat storage subsystem to recover the heat from the intermediate cooling water of the gas generator set. Waste heat from cold water; when the return water temperature of the intermediate cooling water of the gas generator set is higher than the target value, the intermediate cooling water of the gas generator set is cooled by a second heat dissipation device; when the medium and high temperature flue gas of the gas generator set is recovered and utilized, the specific steps include: the high temperature flue gas discharged from the gas generator set is preferentially fed into the waste heat lithium bromide unit for utilization; the low temperature flue gas discharged from the waste heat lithium bromide unit is fed into the low temperature flue gas heat exchanger to recover the heat of the low temperature flue gas; the hot water generated after the heat is recovered by the low temperature flue gas heat exchanger is preferentially fed into the hot water storage tank to meet user needs; when the external heat load demand is low or in non-heating conditions, the heat in the hot water generated by the low temperature flue gas heat exchanger is recovered through the cross-seasonal heat storage subsystem.

[0015] The technical solution of this invention has the following advantages: The gas and geothermal complementary integrated energy supply system coupled with interseasonal thermal storage provided by this invention recovers the waste heat of gas generator sets through a lithium bromide waste heat generator unit, realizing a more comprehensive utilization of waste heat resources from gas generator sets and improving the overall thermal efficiency of the system. By recovering and storing the waste heat of gas generator sets through an interseasonal thermal storage subsystem, and then using the stored waste heat through a ground source heat pump system to provide heating and cooling services to users, this system solves the problem of temporal and spatial mismatch between the continuous heat production of gas generator sets and the seasonal heating needs of buildings. The heat recovered during transitional seasons and low-load conditions is stored for use in winter or during peak heating periods, achieving interseasonal energy scheduling, improving waste heat utilization efficiency, reducing operating costs, and enhancing overall energy efficiency.

[0016] The gas and geothermal complementary integrated energy supply system with coupled cross-seasonal heat storage provided by this invention deeply couples the gas distributed energy supply system with the ground source heat pump system. The high and low temperature heat dissipation system of the gas generator set and the cross-seasonal heat storage form a composite waste heat recovery system, which not only solves the problem of poor heat dissipation effect of the gas generator set in the high temperature environment in summer, but also realizes the full recovery and utilization of waste heat from the gas generator set, reducing the power and water consumption of the gas generator set cooling system.

[0017] The gas-geothermal complementary integrated energy supply system with coupled cross-seasonal heat storage provided by this invention deeply couples a gas-fired distributed energy supply system with a ground source heat pump system. It recovers and stores excess heat generated by the system during summer and transitional seasons and under low-load operating conditions, and utilizes buried heat exchange coils to achieve cross-seasonal energy supply. This achieves thermal balance of the ground source heat pump, effectively solving the long-term thermal imbalance problem of the ground source heat pump. At the same time, it significantly improves the heat exchange efficiency of the ground source heat pump system, saves operating energy consumption, and solves the problem of waste heat from gas generator sets during the non-heating season. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the integrated gas and geothermal energy supply system coupled with cross-seasonal thermal storage in an embodiment of the present invention. Figure 2 This is a schematic diagram of the layout of the inter-seasonal thermal storage subsystem in the coupled inter-seasonal thermal storage embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Gas generator set; 2. Waste heat lithium bromide generator set; 3. Ground source heat pump unit; 4. Low temperature flue gas heat exchange device; 5. Thermal storage device; 6. Hot water storage tank; 7. First heat dissipation device; 8. Second heat dissipation device; 9. Cross-seasonal thermal storage subsystem; 901. A-zone thermal storage underground coil; 902. B-zone thermal storage underground coil; 903. C-zone thermal storage underground coil. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and defined, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] like Figure 1As shown, this embodiment provides a gas and geothermal complementary integrated energy supply system coupled with interseasonal thermal storage, including: a gas generator set 1; a waste heat lithium bromide unit 2 connected to the gas generator set 1, wherein the waste heat lithium bromide unit 2 utilizes a portion of the waste heat from the gas generator set 1 to provide heating and cooling services to users; an interseasonal thermal storage subsystem 9 connected to the gas generator set 1, wherein the interseasonal thermal storage subsystem 9 is used to recover and store another portion of the waste heat from the gas generator set 1; and a ground source heat pump system connected to the interseasonal thermal storage subsystem 9, wherein the ground source heat pump system utilizes the waste heat stored in the interseasonal thermal storage subsystem 9 to provide heating and cooling services to users.

[0026] The waste heat lithium bromide unit 2 utilizes the waste heat from the high-temperature cylinder liner water and high-temperature flue gas of the gas generator set 1 to provide heating and cooling services to users; the cross-seasonal heat storage subsystem 9 recovers the waste heat from the high-temperature cylinder liner water and intermediate cooling water of the gas generator set 1.

[0027] The gas and geothermal complementary integrated energy supply system coupled with interseasonal thermal storage also includes a first heat dissipation device 7, which is connected to the high-temperature cylinder liner water circuit of the gas generator set 1. The waste heat of the high-temperature cylinder liner water of the gas generator set 1 is preferentially utilized through the waste heat lithium bromide unit 2. When the temperature of the cylinder liner water discharged from the waste heat lithium bromide unit 2 is higher than a first target value, the waste heat of the high-temperature cylinder liner water of the gas generator set 1 is simultaneously recovered using the interseasonal thermal storage subsystem 9. When the return water temperature of the high-temperature cylinder liner water of the gas generator set 1 is higher than a second target value, the high-temperature cylinder liner water of the gas generator set 1 is cooled by the first heat dissipation device 7.

[0028] The gas and geothermal complementary integrated energy supply system coupled with interseasonal thermal storage also includes a second heat dissipation device 8, which is connected to the intermediate cooling water circuit of the gas generator set 1; the waste heat of the intermediate cooling water of the gas generator set 1 is preferentially recovered by the interseasonal thermal storage subsystem 9; when the return water temperature of the intermediate cooling water of the gas generator set 1 is higher than the target value, the intermediate cooling water of the gas generator set 1 is cooled by the second heat dissipation device 8.

[0029] The waste heat in the high-temperature flue gas of the gas generator set 1 is utilized by the waste heat lithium bromide unit 2 to become low-temperature flue gas, and the cross-seasonal heat storage subsystem 9 recovers the waste heat in the low-temperature flue gas.

[0030] The integrated gas and geothermal energy supply system coupled with interseasonal thermal storage also includes a low-temperature flue gas heat exchange device 4 and a hot water storage tank 6. The low-temperature flue gas heat exchange device 4 is connected to the flue gas outlet pipeline of the waste heat lithium bromide unit 2. The hot water storage tank 6 is connected to the low-temperature flue gas heat exchange device 4 and the interseasonal thermal storage subsystem 9. The high-temperature flue gas discharged from the gas generator set 1 is preferentially fed into the waste heat lithium bromide unit 2 for utilization, and the low-temperature flue gas discharged from the waste heat lithium bromide unit 2 is fed into the low-temperature flue gas heat exchange device 4 for heat recovery. The hot water generated after the heat is recovered by the low-temperature flue gas heat exchange device 4 is preferentially fed into the hot water storage tank 6 to meet user needs. When the external heat load demand is low or in non-heating conditions, the heat in the hot water generated by the low-temperature flue gas heat exchange device 4 is recovered through the interseasonal thermal storage subsystem 9.

[0031] like Figure 2 As shown, the cross-seasonal thermal storage subsystem 9 includes a thermal storage underground coil 901 in zone A, a thermal storage underground coil 902 in zone B, and a thermal storage underground coil 903 in zone C. The thermal storage underground coil 901 in zone A is used to store the waste heat of high-temperature cylinder liner water; the thermal storage underground coil 902 in zone B is used to store the waste heat of low-temperature flue gas; and the thermal storage underground coil 903 in zone C is used to store the waste heat of intermediate-cooled water. The thermal storage underground coils 901, 902, and 903 in zone A and zone C are all connected to the ground source heat pump system.

[0032] The buried thermal storage coils 901 in zone A, 902 in zone B, and 903 in zone C are arranged in concentric circles or concentric rectangles, and are arranged sequentially from the inside to the outside. The temperature of the recovered heat decreases from high to low. This layout is conducive to efficient heat storage, effectively reduces heat loss, and improves the performance of the entire cross-seasonal thermal storage system.

[0033] The interseasonal thermal storage subsystem 9 also includes a thermal storage device 5 connected to the underground thermal storage coils 901 (Area A), 902 (Area B), and 903 (Area C). The thermal storage device 5 can store both hot and cold water according to operational needs. Specifically, this integrated gas and geothermal energy supply system, coupled with interseasonal thermal storage, includes a gas generator set 1, a waste heat lithium bromide unit 2, a ground source heat pump unit 3, a low-temperature flue gas heat exchanger 4, a thermal storage device 5, a hot water storage tank 6, a first heat dissipation device 7, a second heat dissipation device 8, underground thermal storage coils 901 (Area A), 902 (Area B), and 903 (Area C); and pump bodies P1, P2, P3, P4, P5, and P6. Pump body P7 and pump body P8; also includes three-way valves F1, F2, F3, F4, F5, F6, F7, F8 and F9; also includes electric valves a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w and x.

[0034] Among them, the high-temperature cylinder liner water circuit between gas generator set 1 and waste heat lithium bromide unit 2 is equipped with pump body P1, three-way valve F1, three-way valve F2, electric valve u, and electric valve v; the first heat dissipation device 7 is connected to the underground heat storage coil 901 in area A through three-way valve F2, three-way valve F3, three-way valve F4, and pipelines. Electric valve a is installed on the pipeline between three-way valve F3 and underground heat storage coil 901 in area A, and electric valve b and pump body P2 are installed on the pipeline between underground heat storage coil 901 in area A and three-way valve F4; gas generator set 1, waste heat lithium bromide unit 2, and chimney are connected through three-way valve F9 and pipelines; electric valve x and electric valve w are installed on the pipeline between waste heat lithium bromide unit 2 and the user; low-temperature flue gas heat exchange device 4 is installed in the waste heat lithium bromide unit 2. On the flue gas pipeline between the thermal lithium bromide unit 2 and the gas generator unit 1, the low-temperature flue gas heat exchange device 4, the hot water storage tank 6, and the underground thermal storage coil 902 in Zone B are connected by three-way valves F7 and F8 and pipelines. An electric valve r is installed on the pipeline between the low-temperature flue gas heat exchange device 4 and the three-way valve F7, an electric valve q is installed on the pipeline between the low-temperature flue gas heat exchange device 4 and the three-way valve F8, an electric valve c is installed on the pipeline between the three-way valve F7 and the underground thermal storage coil 902 in Zone B, an electric valve d and a pump body P5 are installed on the pipeline between the three-way valve F8 and the underground thermal storage coil 902 in Zone B; an electric valve t and a pump body P8 are installed on the pipeline between the three-way valve F7 and the hot water storage tank 6, and an electric valve is installed on the pipeline between the three-way valve F8 and the hot water storage tank 6. The gas generator set 1, the second cooling device 8, and the underground thermal storage coil 903 in zone C are connected by three-way valves F5 and F6 and pipelines. A pump body P3 is installed on the pipeline between the second cooling device 8 and the three-way valve F6. An electric valve e is installed on the pipeline between the three-way valve F5 and the underground thermal storage coil 903 in zone C. An electric valve f and a pump body P4 are installed on the pipeline between the three-way valve F6 and the underground thermal storage coil 903 in zone C. The thermal storage device 5 is connected to the ground source heat pump unit 3 via pipelines. The ground source heat pump unit 3 is connected to the cross-sectional area... Electric valves o and p, and pump body P6 are installed on the pipelines between the seasonal thermal storage subsystems 9. Electric valves m and n, and pump body P7 are installed on the pipelines between the thermal storage device 5 and the thermal storage underground coil. Electric valves g and h are installed on the pipelines between the thermal storage underground coil 901 in area A and the thermal storage device 5. Electric valves k and l are installed on the pipelines between the thermal storage underground coil 902 in area B and the thermal storage device 5. Electric valves i and j are installed on the pipelines between the thermal storage underground coil 903 in area C and the thermal storage device 5.

[0035] In the heat storage mode, the cross-seasonal heat storage subsystem 9 recovers heat from the cylinder liner water, the heat source water for low-temperature flue gas heat exchange, and the intermediate cooling water system through the underground heat storage coil 901 in zone A, the underground heat storage coil 902 in zone B, and the underground heat storage coil 903 in zone C.

[0036] In heat release mode, electric valves g, h, i, j, k, and i are opened according to external energy demand to provide external heat through the ground source heat pump system or the inter-seasonal thermal storage system. During peak heating demand periods and when the outlet water temperature of the buried coil is higher than 45℃, the inter-seasonal thermal storage system is prioritized to directly supply heat source water. The heat source water enters the thermal storage device 5 for buffering before providing stable heating to users. When the outlet water temperature is lower than 45℃, the ground source heat pump system is activated to supplement energy supply. This minimizes the peak-shaving capacity of the ground source heat pump unit, saving system investment. This system utilizes the inter-seasonal thermal storage subsystem 9 and the ground source heat pump system to provide peak-shaving heat to the gas-fired distributed energy supply system, replacing the traditional peak-shaving energy supply method of gas boilers or direct-fired turbines, and realizing renewable energy heating substitution.

[0037] The integrated gas and geothermal energy supply system, which couples seasonal thermal storage, is equipped with an advanced control and regulation device to ensure efficient and stable operation, coordination between subsystems, and rational energy allocation and utilization. This device mainly consists of temperature sensors, three-way valves, and a central controller. Temperature sensors are precisely positioned at several key locations within the system, including but not limited to the flue gas outlet of gas generator set 1, the inlet and outlet of cylinder liner water and intercooler water, various interfaces of the waste heat lithium bromide generator set 2, different areas of the buried pipes, and indoor and outdoor spaces of the building. These temperature sensors possess high-precision temperature sensing capabilities, enabling real-time and accurate monitoring of temperature data at corresponding locations, and rapidly and stably transmitting the collected temperature information to the subsequent control unit in the form of electrical or digital signals. The central controller, as the core hub of the entire control and regulation device, possesses powerful data processing and system control capabilities. It receives data from temperature sensors and other monitoring devices, including but not limited to various operating parameters such as pressure, flow rate, and power. The central controller has built-in preset control strategies, which are constructed based on the physical principles and thermodynamic laws of system operation, as well as a large amount of actual operating data. Based on varying seasonal conditions, load conditions, and changes in user needs, the central controller can intelligently and precisely control the entire integrated energy supply system according to preset control strategies. Specifically, the central controller can automatically adjust the operating power of the gas generator unit 1 to meet power generation requirements while achieving efficient waste heat recovery and utilization; it can flexibly switch the operating mode of the waste heat lithium bromide unit 2 to adapt to different heat utilization scenarios; it can precisely adjust the operating parameters of the ground source heat pump unit 3 to ensure efficient operation of the ground source heat pump system under different operating conditions; it can also regulate the speed of each pump in real time to optimize fluid circulation efficiency within the system; and it can adjust the operating status of each electric valve and three-way valve. Through the comprehensive and precise control of the central controller, the entire integrated energy supply system is ensured to always operate in a highly efficient and stable state, maximizing energy utilization efficiency and system economic benefits.

[0038] In terms of waste heat recovery and utilization, unlike existing gas-fired distributed energy systems that only partially recover waste heat from the high-temperature flue gas of the internal combustion engine or the cylinder liner water heat source, this application innovatively expands the scope of waste heat recovery, achieving comprehensive recovery of the heat dissipation from the cooling water in the gas-fired internal combustion engine, the heat dissipation from the cylinder liner water, and the waste heat from the low-temperature flue gas at the tail end, thus constructing a composite waste heat recovery system. This comprehensive and efficient waste heat recovery strategy significantly improves the resource utilization rate of waste heat from the gas-fired internal combustion engine, and can increase the overall thermal efficiency of the system by 5%-10%.

[0039] To address the temporal and spatial mismatch between the continuous heat production of gas-fired internal combustion engines and the seasonal heating demands of buildings, this application constructs a cross-seasonal heat storage system based on a buried pipe heat exchange field. During transitional seasons and low-load operating conditions, excess heat recovered by the system is effectively stored in the underground soil through heat exchange between the buried pipe heat exchange field and the soil. The design of the buried pipe heat exchange field fully considers key parameters such as the thermophysical properties of the soil, pipe spacing, and depth to ensure the high efficiency and stability of heat storage and release. When winter or peak heating season arrives, the heat stored in the underground soil is extracted again through a carefully designed heat medium circulation loop and transported to the user side to meet heating demands. This cross-seasonal energy regulation method overcomes the drawbacks of traditional systems, such as low waste heat utilization efficiency and high operating costs, achieving an energy utilization efficiency of over 95%.

[0040] This application achieves deep coupling between a gas-fired distributed energy supply system and a ground-source heat pump system. It combines the high and low temperature cooling system of a gas-fired internal combustion engine with a cross-seasonal heat storage subsystem 9 to form a composite waste heat recovery system. In high-temperature summer conditions, the large amount of heat generated by the internal combustion engine is preferentially and rapidly transferred to the buried pipe heat exchange field through this composite system. This process not only alleviates the heat dissipation burden on the internal combustion engine itself and effectively improves the operation of the cooling system under high-temperature conditions, ensuring the stable and efficient operation of the internal combustion engine, but also achieves full recovery and utilization of waste heat from the gas-fired internal combustion engine generator set. This can reduce the power consumption of the internal combustion engine cooling system by more than 20% and save water consumption. Simultaneously, the coupling with the ground-source heat pump system creates complementary advantages. During summer and transitional seasons, and under low-load operating conditions, excess waste heat generated by the gas-fired distributed energy supply system is recovered and stored underground, achieving cross-seasonal energy supply utilization through buried heat exchange coils. In winter, it is extracted for auxiliary heating, thereby effectively balancing the heating and cooling loads of the ground-source heat pump system and achieving balanced operation of the ground-source heat pump system. This improvement not only solves the thermal imbalance problem that occurs during the long-term operation of the ground source heat pump system and significantly improves the heat exchange efficiency of the ground source heat pump system, saving more than 30% of operating energy consumption, but also eliminates the waste of waste heat of the unit during the non-heating season, forming the optimal complementary utilization of gas and geothermal energy, and realizing the maximum utilization of energy.

[0041] This integrated gas and geothermal energy supply system, which couples cross-seasonal thermal storage, has multiple operating modes: Winter heating mode: Gas generator set 1, waste heat lithium bromide unit 2, and low-temperature flue gas heat exchanger 4 are started. The ground source heat pump system, the A-zone heat storage buried coil 901 system, and the B-zone heat storage buried coil 902 are shut down. Electric valves a, b, c, d, g, h, i, j, l, k, m, n, o, and p are closed. Pumps P2, P5, P6, and P7 are shut down. Other equipment operates normally and provides heat to the outside. At the same time, the medium-cooled water discharged from gas generator set 1 at about 70°C is regulated by the medium three-way valve F5 and the three-way valve F6 and enters the C-zone heat storage buried coil 903 heat exchange system for cooling and heat exchange, storing the heat in the soil for recovery and storage.

[0042] Winter peak-shaving heating mode: Gas generator set 1, waste heat lithium bromide unit 2, low-temperature flue gas heat exchanger 4, and ground source heat pump system are started; the heat storage section of the inter-seasonal heat storage subsystem 9 is shut down, i.e., electric valves a and b, c and d, f and e are closed, and pumps P2, P4, and P5 are closed; other equipment operates normally, providing heat to the outside. During peak heating demand periods and when the outlet water temperature of the buried coil is higher than 45℃, the inter-seasonal heat storage system is prioritized to directly supply heat source water to the outside. The heat source water enters the heat storage device 5 for buffering before providing stable heating to users. When the outlet water temperature is lower than 45℃, the ground source heat pump system is started to supplement energy supply, which can minimize the peak-shaving unit capacity of the ground source heat pump and save system investment. This system utilizes the inter-seasonal heat storage subsystem 9 and the ground source heat pump system to provide peak-shaving heating to the gas-fired distributed energy supply system, replacing the traditional peak-shaving energy supply method of gas boilers or direct-fired turbines, and realizing renewable energy heating substitution.

[0043] Winter heating and heat storage mode: Gas generator set 1, waste heat lithium bromide unit 2, and low-temperature flue gas heat exchange device 4 are started. The ground source heat pump system and heat storage device 5 are shut down, i.e., electric valves g and h, i and j, l and k, m and n, o and p are closed, and pump bodies P6 and P7 are closed. Other equipment operates normally, providing heat to the outside world. This mode is mainly used when the heating load demand is low in winter. The cylinder liner water, intercooled water, and heat source water from the low-temperature flue gas heat exchange generated by the system are regulated and distributed through three-way valves F2, F3, F4, F5, F6, F7, and F8, respectively. Excess heat is stored in the underground heat storage coil system, realizing simultaneous external heating and waste heat recovery and utilization.

[0044] Summer standard cooling mode: Gas generator set 1, waste heat lithium bromide unit 2, and low-temperature flue gas heat exchange device 4 are started. The ground source heat pump system and the A-zone heat storage buried coil 901 system are shut down, that is, electric valves a and b, g and h, i and j, l and k, m and n, o and p are shut down, and pumps P2, P6, and P7 are shut down. Other equipment operates normally to meet the user's cooling and domestic hot water energy supply needs. Meanwhile, the medium-cooled water at around 70°C discharged from the internal combustion engine generator set is regulated by three-way valves F5 and F6 and enters the heat exchange system of buried thermal storage coil 903 in Zone C for cooling and heat exchange. The hot water generated by the low-temperature flue gas hot water heat exchanger is preferentially sent to the hot water storage tank 6 to meet user needs. When the demand for domestic hot water decreases in summer, the heat source water generated by the low-temperature flue gas heat exchange device 4 is regulated by three-way valves F7 and F8 and enters the heat exchange system of buried thermal storage pipe in Zone B for heat storage. The excess heat of the system is stored in the soil to achieve cross-seasonal storage and utilization.

[0045] Summer peak-shaving cooling mode: Gas generator set 1, waste heat lithium bromide unit 2, low-temperature flue gas heat exchange device 4, and ground source heat pump system are started; the heat storage part of the inter-seasonal heat storage subsystem 9 is shut down, that is, electric valves a and b, electric valves c and d, electric valves f and e, electric valves m and n are shut down, and pump bodies P2, P4, P5, and P7 are shut down; other equipment operates normally to meet the user's cooling and domestic hot water energy supply needs. This system uses the ground source heat pump system to provide peak-shaving cooling for the gas-fired distributed energy supply system, replacing the traditional electric refrigeration or direct-fired turbine peak-shaving cooling method, and realizing the replacement of renewable energy cooling.

[0046] Summer cooling and heat storage mode: Gas generator set 1, waste heat lithium bromide unit 2, and low-temperature flue gas heat exchange device 4 are started. The ground source heat pump system and heat storage device 5 are shut down, i.e., electric valves g and h, i and j, l and k, m and n, o and p are closed, and pump bodies P6 and P7 are closed. Other equipment operates normally, providing heat to the outside world. This mode is mainly used when the cooling load demand is low in summer. The cylinder liner water, intercooling water, and heat source water for low-temperature flue gas heat exchange generated by the system are regulated and distributed through three-way valves F2, F3, F4, F5, F6, F7, and F8, respectively. Excess heat is stored in the underground heat storage coil system, realizing simultaneous cooling to the outside world and completing the recovery and storage of waste heat.

[0047] The heat storage mode during the transition season is similar to the heat storage mode for cooling in summer, so it will not be described in detail here.

[0048] Another embodiment also provides an operation method for a gas and geothermal complementary integrated energy supply system coupled with inter-seasonal thermal storage, including the following steps: using the waste heat from the cylinder liner water and high-temperature flue gas of the gas generator set 1 through the waste heat lithium bromide unit 2 to provide heating and cooling services to users; recovering the cylinder liner water, intermediate cooling water, and waste heat from the low-temperature flue gas of the gas generator set 1 after being utilized by the waste heat lithium bromide unit 2 through the inter-seasonal thermal storage subsystem 9; and using the heat stored in the inter-seasonal thermal storage subsystem 9 through the ground source heat pump system to provide heating and cooling services to users.

[0049] The recovery and utilization of heat from the cylinder liner water of the gas generator set 1 specifically includes the following steps: Prioritizing the utilization of waste heat from the high-temperature cylinder liner water of the gas generator set 1 through the waste heat lithium bromide unit 2; when the temperature of the cylinder liner water discharged from the waste heat lithium bromide unit 2 is higher than a first target value, simultaneously utilizing the inter-seasonal heat storage subsystem 9 to recover the waste heat from the high-temperature cylinder liner water of the gas generator set 1; when the return water temperature of the high-temperature cylinder liner water of the gas generator set 1 is higher than a second target value, cooling the high-temperature cylinder liner water of the gas generator set 1 is achieved through the first cooling device 7; the recovery and utilization of heat from the intercooling water of the gas generator set 1 specifically includes the following steps: prioritizing the utilization of heat from the intercooling water of the gas generator set 1 through the inter-seasonal heat storage subsystem 9 to recover the heat from the intercooling water of the gas generator set 1. Waste heat from water; when the return water temperature of the intermediate cooling water of the gas generator set 1 is higher than the target value, the intermediate cooling water of the gas generator set 1 is cooled by the second heat dissipation device 8; when the medium and high temperature flue gas of the gas generator set 1 is recovered and utilized, the specific steps are as follows: the high temperature flue gas discharged from the gas generator set 1 is preferentially fed into the waste heat lithium bromide unit 2 for utilization; the low temperature flue gas discharged from the waste heat lithium bromide unit 2 is fed into the low temperature flue gas heat exchange device 4 to recover the heat of the low temperature flue gas; the hot water generated after the heat is recovered by the low temperature flue gas heat exchange device 4 is preferentially fed into the hot water storage tank 6 to meet the user's needs; when the external heat load demand is low or the non-heating condition is not in operation, the heat in the hot water generated by the low temperature flue gas heat exchange device 4 is recovered by the cross-seasonal heat storage subsystem 9.

[0050] The specific method for recovering heat from the cylinder liner water is as follows: 95°C water discharged from the gas generator set 1 is preferentially fed into the waste heat lithium bromide unit 2 for heat exchange. When the temperature of the cylinder liner water return from the waste heat lithium bromide unit 2 is higher than 70°C, the inter-seasonal heat storage subsystem 9 is activated in heat storage mode. Based on temperature and pressure feedback signals, a portion of the cylinder liner water flow is adjusted through three-way valves F2, F3, and F4 to enter the buried heat storage coil 901 in area A for cooling and heat exchange, storing excess heat in the soil for inter-seasonal utilization. When the cylinder liner water return temperature is still higher than the unit's return water temperature requirement after the above two methods of heat exchange and cooling, it is regulated through three-way valves F3 and F4 to enter the first heat dissipation device 7 for heat dissipation and cooling, controlling the cylinder liner water return temperature within the optimal range, not lower than 55°C, maximizing the utilization of the cylinder liner water waste heat, and ensuring efficient and safe operation of the unit.

[0051] The specific method for recovering heat from the intermediate cooling water is as follows: Unlike conventional systems, the intermediate cooling water discharged from the gas generator set 1 at around 70°C is regulated by three-way valves F5 and F6 and preferentially enters the inter-seasonal thermal storage subsystem 9 for heat storage and utilization. It is cooled and exchanged through the underground thermal storage coil 903 in zone C, and the heat is stored in the soil for recovery and storage. At the same time, the temperature of the return water is monitored by a temperature controller on the return water pipeline. When the return water temperature is too high, a portion of the flow of intermediate cooling water is regulated by three-way valve F5 to enter the second heat dissipation device 8. Through the above-mentioned composite system, not only is the waste heat recovery and utilization of the low-temperature intermediate cooling water realized, but the heat dissipation pressure of the second heat dissipation device 8 is also relieved. This effectively improves the operating effect of the heat dissipation system in high-temperature environments, controls the return water temperature of the intermediate cooling water within the optimal range, reduces the power consumption and water consumption of the cooling system by 20%, and ensures the efficient and safe operation of the unit.

[0052] The specific method for recovering heat from low-temperature flue gas is as follows: the high-temperature flue gas discharged from the gas generator set 1 is preferentially fed into the waste heat lithium bromide unit 2 for use in providing heating or cooling to users. Then, the low-temperature flue gas discharged from the waste heat lithium bromide unit 2 is fed into the low-temperature flue gas heat exchange device 4 to heat the heat source water, thereby recovering the heat from the low-temperature flue gas. The resulting hot water is preferentially fed into the hot water storage tank 6 to meet user needs. When the external heat load demand is low or there is no heating, the heat source water is regulated through three-way valves F7 and F8 and fed into the underground heat storage coil 902 in Zone B for heat storage, storing the excess heat in the soil to achieve cross-seasonal storage and utilization.

[0053] In summary, this integrated gas and geothermal energy supply system, coupled with interseasonal thermal storage, combines the high and low temperature cooling system of the gas internal combustion engine with the interseasonal thermal storage subsystem 9 to form a composite waste heat recovery system. This system not only efficiently recovers heat from the cylinder liner water and intercooler water, but also cools these systems during the heat recovery process. Furthermore, through control components such as three-way valves and a rational heat exchange design, the system intelligently adjusts the coolant ratio flowing through the underground thermal storage coil and the high and low temperature cooling system of the internal combustion engine based on the engine load and ambient temperature, further ensuring the stable and efficient operation of the gas generator set 1. Simultaneously, the recovered heat is transferred to the interseasonal thermal storage subsystem 9, achieving optimal operation throughout the year. Moreover, the interseasonal thermal storage subsystem 9 and the high and low temperature cooling system of the internal combustion engine can serve as backups for each other. In the event of a failure in any of the first cooling device 7, the second cooling device 8, or the underground thermal storage coil, or if the cooling requirements cannot be met, the system can switch between them, improving its safe and reliable operation. Furthermore, the system can flexibly adjust heat transfer to different areas according to their temperature and heat demands. Meanwhile, the ground source heat pump unit 3 is also connected to the thermal storage device 5, which provides heating and cooling to users. This integrated energy supply system that combines gas and geothermal energy for cross-seasonal thermal storage is conducive to efficient heat storage, effectively reduces heat loss, and improves the performance of the entire cross-seasonal thermal storage system. In this integrated energy supply system that combines gas and geothermal energy for cross-seasonal thermal storage, the thermal storage device 5 can store both hot and cold water according to operational needs.

[0054] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to cover all possible implementations. Those skilled in the art will recognize that various variations and modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations and modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A gas-geothermal complementary integrated energy supply system coupled with cross-seasonal thermal storage, characterized in that, include: Gas generator set (1); The waste heat lithium bromide unit (2) is connected to the gas generator set (1), and the waste heat lithium bromide unit (2) uses a portion of the waste heat from the gas generator set (1) to provide heating and cooling services to users. A cross-seasonal thermal storage subsystem (9) is connected to the gas generator set (1), and the cross-seasonal thermal storage subsystem (9) is used to recover and store another part of the waste heat of the gas generator set (1); The ground source heat pump system is connected to the cross-seasonal heat storage subsystem (9), which uses the waste heat stored in the cross-seasonal heat storage subsystem (9) to provide heating and cooling services to users.

2. The integrated energy supply system combining gas and geothermal energy with cross-seasonal thermal storage as described in claim 1, characterized in that, The waste heat lithium bromide unit (2) uses the waste heat in the high-temperature cylinder liner water and high-temperature flue gas of the gas generator unit (1) to provide users with heating and cooling services. The interseasonal thermal storage subsystem (9) recovers the waste heat from the high-temperature cylinder liner water and intermediate cooling water of the gas generator set (1).

3. The integrated energy supply system for gas and geothermal energy coupled with cross-seasonal thermal storage as described in claim 2, characterized in that, It also includes a first heat dissipation device (7), which is connected to the high-temperature cylinder liner water circuit of the gas generator set (1); The waste heat of the high-temperature cylinder liner water of the gas generator set (1) is preferentially utilized through the waste heat lithium bromide unit (2); when the temperature of the cylinder liner water discharged from the waste heat lithium bromide unit (2) is higher than the first target value, the waste heat of the high-temperature cylinder liner water of the gas generator set (1) is recovered by the cross-seasonal heat storage subsystem (9); when the return water temperature of the high-temperature cylinder liner water of the gas generator set (1) is higher than the second target value, the high-temperature cylinder liner water of the gas generator set (1) is cooled by the first heat dissipation device (7).

4. The integrated energy supply system for gas and geothermal energy coupled with cross-seasonal thermal storage as described in claim 2, characterized in that, It also includes a second heat dissipation device (8), which is connected to the intermediate cooling water circuit of the gas generator set (1); The waste heat of the intermediate cooling water of the gas generator set (1) is recovered by the cross-seasonal thermal storage subsystem (9) first; when the return water temperature of the intermediate cooling water of the gas generator set (1) is higher than the target value, the intermediate cooling water of the gas generator set (1) is cooled by the second heat dissipation device (8).

5. The integrated energy supply system for gas and geothermal energy coupled with cross-seasonal thermal storage as described in claim 2, characterized in that, The waste heat in the high-temperature flue gas of the gas generator set (1) is used by the waste heat lithium bromide unit (2) to become low-temperature flue gas, and the cross-seasonal heat storage subsystem (9) recovers the waste heat in the low-temperature flue gas.

6. The integrated energy supply system for gas and geothermal energy coupled with cross-seasonal thermal storage as described in claim 5, characterized in that, It also includes a low-temperature flue gas heat exchanger (4) and a hot water storage tank (6); The low-temperature flue gas heat exchange device (4) is connected to the flue gas outlet pipeline of the waste heat lithium bromide unit (2); The hot water storage tank (6) is connected to the low-temperature flue gas heat exchange device (4) and the cross-seasonal heat storage subsystem (9); The high-temperature flue gas discharged from the gas generator set (1) is preferentially fed into the waste heat lithium bromide unit (2) for utilization. The low-temperature flue gas discharged from the waste heat lithium bromide unit (2) is fed into the low-temperature flue gas heat exchange device (4) to recover the heat of the low-temperature flue gas. The hot water generated after the low-temperature flue gas heat exchange device (4) recovers the heat is preferentially fed into the hot water storage tank (6) to meet the user's needs. When the external heat load demand is low or the heating is not in operation, the heat in the hot water generated by the low-temperature flue gas heat exchange device (4) is recovered through the cross-seasonal heat storage subsystem (9).

7. The integrated gas and geothermal energy supply system with coupled cross-seasonal thermal storage as described in claim 5, characterized in that, The cross-seasonal thermal storage subsystem (9) includes thermal storage underground coil (901) in area A, thermal storage underground coil (902) in area B, and thermal storage underground coil (903) in area C. The underground thermal storage coil (901) in Zone A is used to store the waste heat of the high-temperature cylinder liner water; The underground thermal storage coil (902) in Zone B is used to store the waste heat of low-temperature flue gas; The underground thermal storage coil (903) in Zone C is used to store the waste heat of the medium-cooled water; The underground thermal storage coils (901) in Zone A, (902) in Zone B, and (903) in Zone C are all connected to the ground source heat pump system.

8. The integrated energy supply system for gas and geothermal energy coupled with cross-seasonal thermal storage as described in claim 7, characterized in that, The underground thermal storage coils (901) in zone A, (902) in zone B, and (903) in zone C are arranged in concentric circles or concentric rectangles, and are arranged from the inside to the outside as follows: underground thermal storage coils (901) in zone A, (902) in zone B, and (903) in zone C.

9. An operation method for a gas-geothermal complementary integrated energy supply system coupled with cross-seasonal thermal storage, characterized in that, Includes the following steps: The waste heat lithium bromide unit (2) utilizes the waste heat in the cylinder liner water and high-temperature flue gas of the gas generator set (1) to provide users with heating and cooling services. The cylinder liner water and intercooling water of the gas generator set (1) are recovered through the cross-seasonal thermal storage subsystem (9), and the waste heat that is used by the waste heat lithium bromide unit (2) becomes low-temperature flue gas. The ground source heat pump system utilizes the heat stored in the cross-seasonal heat storage subsystem (9) to provide heating and cooling services to users.

10. The operation method of the gas and geothermal complementary integrated energy supply system coupled with cross-seasonal thermal storage according to claim 9, characterized in that, When recovering and utilizing the heat from the cylinder liner water of a gas generator set (1), the specific steps include the following: The waste heat of the high-temperature cylinder liner water of the gas generator set (1) is preferentially utilized through the waste heat lithium bromide unit (2); When the temperature of the cylinder liner water discharged from the waste heat lithium bromide unit (2) is higher than the first target value, the waste heat of the high temperature cylinder liner water of the gas generator unit (1) is recovered by using the cross-seasonal heat storage subsystem (9). When the return water temperature of the high-temperature cylinder liner water of the gas generator set (1) is higher than the second target value, the high-temperature cylinder liner water of the gas generator set (1) is cooled by the first heat dissipation device (7). When recovering and utilizing the heat from the cooling water of the gas generator set (1), the specific steps include the following: Priority is given to utilizing the cross-seasonal thermal storage subsystem (9) to recover the waste heat from the intermediate cooling water of the gas generator set (1); When the return water temperature of the intermediate cooling water of the gas generator set (1) is higher than the target value, the intermediate cooling water of the gas generator set (1) is cooled by the second heat dissipation device (8). When recovering and reusing the medium- and high-temperature flue gas from a gas generator set (1), the specific steps include the following: The high-temperature flue gas discharged from the gas generator set (1) is preferentially fed into the waste heat lithium bromide unit (2) for utilization; The low-temperature flue gas discharged from the waste heat lithium bromide unit (2) is introduced into the low-temperature flue gas heat exchange device (4) to recover the heat of the low-temperature flue gas. The hot water generated after the low-temperature flue gas heat exchange device (4) recovers heat is preferentially fed into the hot water storage tank (6) to meet user needs; When the external heat load demand is low or the heating condition is not in operation, the heat in the hot water generated by the low temperature flue gas heat exchange device (4) is recovered through the cross-seasonal heat storage subsystem (9).

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