Waste heat recycling system and method for gas generator set

Abstract

The invention discloses a waste heat recycling system of a gas generator set. The waste heat recycling system comprises a gas generator set body, a waste heat recycling device, an energy conversion device, a storage device, an intelligent control module, a multi-stage heat exchange module, an LNG (Liquefied Natural Gas) cold energy utilization module and an intelligent regulation and control system, the multi-stage heat exchange module comprises a first-stage waste heat boiler, a second-stage SCO2 circulating system and a third-stage condensate water preheater; the waste heat recovery device is connected with the first-stage waste heat boiler and the third-stage condensate water preheater or storage device; the second-stage SCO2 circulating system is connected with the first-stage waste heat boiler, the third-stage condensate water preheater is connected with the second-stage SCO2 circulating system, and the energy conversion device is connected with the second-stage SCO2 circulating system and a storage battery pack of the storage device; the LNG cold energy utilization module is connected to a working medium loop of the secondary SCO2 circulation system; control is carried out through the intelligent control module and the intelligent regulation and control system. The system solves the problems of low waste heat recovery efficiency, low energy utilization rate and insufficient intelligence.

Description

Technical Field

[0001] The present invention relates to the technical field of gas-fired generator sets, and in particular to a waste heat recovery and utilization system and a recovery and utilization method for a gas-fired generator set. Background Art

[0002] Gas-fired generator sets, with their advantages of high efficiency, low pollution, and fast startup, are widely used in industrial, commercial, and power generation sectors. However, during operation, gas-fired generator sets generate a large amount of waste heat, primarily from exhaust, cooling, and lubrication systems. If this waste heat is not recovered and utilized, it not only wastes energy but also causes thermal pollution to the environment.

[0003] Currently, research and application of waste heat recovery from gas-fired generators have achieved considerable success. Common waste heat recovery methods include using waste heat boilers to generate steam to drive steam turbines for power generation, and using waste heat to heat water or air for industrial production or heating. However, existing waste heat recovery systems have several challenges, such as low efficiency, complex systems, high costs, and poor reliability, which hinder the full utilization of waste heat resources.

[0004] Therefore, how to improve the efficiency and reliability of waste heat recovery and utilization of gas-fired generator sets and reduce system costs is an urgent problem to be solved. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a gas generator set waste heat recovery system and a recovery method thereof to solve the problems of low waste heat recovery efficiency, low energy utilization rate and insufficient intelligence proposed in the above background technology.

[0006] The technical solution of the present invention is: a gas generator set waste heat recovery and utilization system, including a gas generator set body, a waste heat recovery device, an energy conversion device, a storage device, an intelligent control module, a multi-stage heat exchange module, an LNG cold energy utilization module and an intelligent control system.

[0007] The gas generator set body is connected to the waste heat recovery device;

[0008] The multi-stage heat exchange module includes a first-stage waste heat boiler, a second-stage SCO2 circulation system, and a third-stage condensate preheater;

[0009] The high-temperature flue gas output end of the waste heat recovery device is connected to the flue gas channel inlet of the first-stage waste heat boiler, and the low-temperature waste heat output end is connected to the third-stage condensate preheater or storage device; the second-stage SCO2 circulation system is connected to the first-stage waste heat boiler and uses the SCO2 working medium for energy circulation; the third-stage condensate preheater is connected to the low-temperature end of the second-stage SCO2 circulation system for preheating condensate; the power input end of the energy conversion device is connected to the turbine shaft of the second-stage SCO2 circulation system, and the power output end is connected to the battery pack of the storage device; the cold energy exchanger of the LNG cold energy utilization module is connected in parallel to the working medium circuit of the second-stage SCO2 circulation system, and the cold energy supply end is connected to the actuator of the intelligent control system;

[0010] The intelligent control module is connected to the gas generator set body, waste heat recovery device, energy conversion device, storage device, multi-stage heat exchange module, LNG cold energy utilization module and intelligent control system respectively, and is used to receive operating data and issue control instructions;

[0011] The intelligent control system is connected to the multi-stage heat exchange module and the LNG cold energy utilization module, and is used to control the heat exchange process and the cold energy utilization process.

[0012] Furthermore, a spiral partition is provided inside the first-stage waste heat boiler to divide the flue gas channel into spiral flow channels; the spiral partition is adjustable.

[0013] Furthermore, the adjustable spiral partition is driven by a motor or a hydraulic drive device to achieve angle adjustment, with an adjustment range of 0°-60° and an accuracy of ±1°.

[0014] Furthermore, the LNG cold energy utilization module includes an LNG storage tank, a vaporizer and a cold energy exchanger, which is used to transfer the cold energy of LNG to the SCO2 working medium.

[0015] Furthermore, the low-temperature waste heat collected by the waste heat recovery device is directly connected to a storage device or a three-stage condensed water preheater for secondary utilization.

[0016] Furthermore, the storage device includes a battery pack and a phase change energy storage unit, which are respectively used to store the electrical energy generated by the energy conversion device and the low-temperature thermal energy collected by the waste heat recovery device.

[0017] The present invention provides a method for recovering and utilizing waste heat from a gas-fired generator set, comprising the following steps:

[0018] A. Waste heat collection: The waste heat recovery device collects the high-temperature flue gas and component waste heat generated by the gas generator set. The high-temperature flue gas temperature is 800-1200°C, and the component waste heat temperature is 100-300°C. The high-temperature flue gas is introduced into the spiral baffle flue gas channel of the first-stage waste heat boiler;

[0019] B. Multi-stage heat exchange: High-temperature flue gas flows in the spiral baffle flue gas channel, exchanges heat with the wall, and heats the SCO2 working medium to 300-400℃ and a pressure of 20-30MPa. The heated SCO2 working medium enters the secondary SCO2 circulation system to drive the secondary SCO2 circulation system turbine unit to generate electricity. The low-temperature SCO2 working medium enters the tertiary condensate preheater to preheat the condensate. The low-temperature SCO2 working medium temperature is 30-60℃.

[0020] C. LNG cold energy utilization: The intelligent control system controls the opening of the cold energy exchanger of the LNG cold energy utilization module based on the SCO2 cycle temperature parameters, injecting -162°C LNG cold energy into the working fluid circuit as needed to cool the SCO2 working fluid or other working fluids;

[0021] D. Energy storage and distribution: The electrical energy generated by the energy conversion device is directly supplied to the electrical equipment, and the remaining electrical energy and recovered low-temperature heat energy are stored in the battery pack and phase change energy storage unit of the storage device respectively;

[0022] E. Intelligent Control: The intelligent control module adjusts the spiral baffle angle, SCO2 circulation flow rate and LNG cold energy supply in real time to keep the system's comprehensive energy efficiency ratio (PER) at 0.78-0.82.

[0023] The beneficial effects of the present invention are:

[0024] 1) The present invention adopts a multi-stage heat exchange module to grade the waste heat of flue gas into high, medium and low temperatures. The first-stage waste heat boiler uses high-temperature flue gas to generate steam, the second-stage SCO2 circulation system uses medium-temperature flue gas to drive the supercritical carbon dioxide circulation, and the third-stage condensate preheater uses low-temperature flue gas to preheat condensate. This fully improves the waste heat recovery efficiency and realizes the efficient utilization of waste heat at different temperature gradients, bringing the waste heat recovery efficiency to 75%-80%. The overall energy efficiency of the system is improved by 20%-25% compared with traditional solutions.

[0025] 2) The spiral baffle flue gas channel design increases the contact area and disturbance between the flue gas and the heat exchange surface, thereby improving the heat exchange efficiency. Compared with the traditional straight channel design, the heat exchange efficiency can be increased by 20%-30%. The adjustable spiral baffle is combined with the intelligent algorithm, and the energy efficiency drop during load fluctuations is reduced from 15% to less than 5%.

[0026] 3) The LNG cold energy utilization module is introduced and coupled with the SCO2 cycle to recover the cold energy during the LNG vaporization process and cool the supercritical carbon dioxide, thereby improving the efficiency of the SCO2 cycle and thus improving the energy utilization rate of the entire system.

[0027] 4) The intelligent control system can collect and analyze system operation data in real time, intelligently adjust the operating parameters of each module according to different working conditions, realize the optimized operation of the system, improve the intelligence level and adaptability of the system, and improve the system operation efficiency by 15%-20% compared with traditional fixed parameter control. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and examples.

[0029] Figure 1 It is a structural block diagram of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below through specific implementation methods.

[0031] refer to Figure 1 The present invention provides a waste heat recovery and utilization system for a gas generator set, comprising a gas generator set body 1, a waste heat recovery device 2, an energy conversion device 5, a storage device 10, an intelligent control module 8, a multi-stage heat exchange module, an LNG cold energy utilization module 7 and an intelligent control system 9.

[0032] The waste heat recovery device is directly connected to the high-temperature flue gas outlet of the gas generator set and the heat dissipation area on the surface of the equipment through a pipeline, collecting the high-temperature flue gas waste heat (about 500-800℃) generated during the power generation process and the radiation / conduction waste heat of components such as the cylinder and exhaust pipe.

[0033] The multi-stage heat exchange module includes a first-stage waste heat boiler 3, a second-stage SCO2 circulation system 4 and a third-stage condensate preheater 6; the air inlet of the first-stage waste heat boiler is connected to the air outlet of the waste heat recovery device, and multiple heat exchange tube bundles are arranged inside to heat water to generate steam; the second-stage SCO2 circulation system includes a compressor, a heat exchanger, a turbine and other equipment. Supercritical carbon dioxide undergoes heating, expansion work, cooling, compression and other processes in the system to achieve energy conversion; the air inlet of the third-stage condensate preheater is connected to the air outlet of the second-stage SCO2 circulation system, and a condensate pipe is arranged inside to preheat the condensate.

[0034] The high-temperature flue gas output of the waste heat recovery unit is connected to the primary waste heat boiler (HRSG) via a spiral baffle flue gas duct. The flue gas exchanges heat with the wall of the spiral duct, heating the SCO2 working fluid within the boiler. A spiral baffle 31 is installed within the primary waste heat boiler (HRSG), dividing the flue gas duct into spiral channels. The spiral baffle 31 is adjustable. The angle of the adjustable spiral baffle 31 is adjustable via a motor or hydraulic drive within a range of 0°-60°, with an accuracy of ±1°.

[0035] The low-temperature waste heat (such as cooling water waste heat) collected by the waste heat recovery device can be directly connected to the storage device or the three-stage condensate preheater for secondary utilization.

[0036] The low-temperature waste heat output end is connected to a three-stage condensate preheater or a storage device.

[0037] The high-pressure SCO2 working fluid (about 30-35 MPa, 300-500°C) heated by the first-stage waste heat boiler is input into the second-stage SCO2 circulation system through a pipeline to drive the energy conversion device (5, such as a turbine generator) to realize heat-to-electricity conversion.

[0038] The low-temperature SCO2 working fluid (about 100-150℃) discharged from the secondary circulation system is connected to the third-stage condensate preheater, connected in parallel with the condensate pipeline, and the condensate is preheated through a plate heat exchanger.

[0039] The power input end of the energy conversion device is connected to the turbine shaft of the secondary SCO2 cycle system, and the output end of the energy conversion device is connected to the battery pack in the storage device through a cable. The electrical energy not directly used is stored in the battery; at the same time, the hot water / steam generated by waste heat recovery is connected to the heat storage tank of the storage device through a pipeline.

[0040] The cold energy exchanger of the LNG cold energy utilization module is connected in parallel to the working fluid circuit of the secondary SCO2 circulation system through a low-temperature pipeline. After the SCO2 working fluid does work (about 150-200℃), it is cooled (down to 50-80℃) to accelerate the condensation and reflux of the working fluid; at the same time, it can cool down components such as the turbine bearings of the energy conversion device.

[0041] The intelligent control module 8 is respectively connected to the gas generator set body 1, the waste heat recovery device 2, the energy conversion device 5, the storage device 10, the multi-stage heat exchange module, the LNG cold energy utilization module 7 and the intelligent control system 9, and is used to receive operating data and issue control instructions;

[0042] The intelligent control system 9 is connected to the multi-stage heat exchange module and the LNG cold energy utilization module 7, and is used to control the heat exchange process and the cold energy utilization process.

[0043] The intelligent control module connects to the sensors of each component via RS485 bus or industrial Ethernet, including:

[0044] Temperature / pressure sensor and speed sensor of the gas generator set;

[0045] Flue gas flow / temperature sensor for waste heat recovery device;

[0046] SCO2 pressure / temperature sensor and condensate flow sensor for multi-stage heat exchange module;

[0047] Generator power sensor for energy conversion device;

[0048] Battery SOC sensor and thermal storage tank level / temperature sensor for storage devices;

[0049] LNG storage tank pressure sensor and vaporizer outlet temperature sensor of the LNG cold energy utilization module.

[0050] The intelligent control module switches the power output path (prioritizing load / energy storage) through the relay group according to the real-time capacity of the storage device, and adjusts the storage / external supply ratio of waste heat hot water through the temperature control valve.

[0051] The LNG cold energy utilization module 7 includes an LNG storage tank, a vaporizer and a cold energy exchanger, and is used to transfer the cold energy of LNG to the SCO2 working medium.

[0052] The storage device includes a battery pack and a phase change energy storage unit, which are used to store the electric energy generated by the energy conversion device 5 and the low-temperature thermal energy collected by the waste heat recovery device 2 respectively.

[0053] In the specific operation process of this embodiment, the high-temperature flue gas generated by the gas generator set body 1 first enters the waste heat recovery device and performs the first heat exchange with the heat medium. After the temperature of the heat medium rises, it is transported to the energy conversion device through the heat medium circulation pump. The energy conversion device converts the heat of the heat medium into electrical energy and stores it in the storage device.

[0054] Flue gas from the waste heat recovery unit enters the primary waste heat boiler. The high-temperature flue gas heats water to produce steam, which drives a steam turbine to generate electricity, improving energy efficiency. The flue gas then enters the secondary SCO2 cycle system. The intermediate-temperature flue gas heats supercritical carbon dioxide, causing it to expand and generate work in the turbine, driving the generator to generate electricity. The supercritical carbon dioxide, which has undergone this work, is now at a high temperature and enters the LNG cold energy utilization module. The LNG cold energy is used to cool it down, lowering its temperature before it returns to the compressor for compression, completing the SCO2 cycle.

[0055] Finally, the low-temperature flue gas that has passed through the secondary SCO2 circulation system enters the tertiary condensate preheater to preheat the condensate. The preheated condensate returns to the boiler system, reducing the boiler's energy consumption.

[0056] The intelligent control module adopts a hierarchical distributed control architecture, including:

[0057] 1. Core Control Unit: Main controller: Advantech UNO-3082G industrial-grade embedded computer, equipped with an Intel Core i7 processor (2.5GHz), 8GB RAM, and a 256GB SSD. It supports Linux / Windows dual systems and meets the requirements of complex algorithm operations. It is equipped with dual power modules (24VDC redundant power supply) and dual CAN bus interfaces to ensure control reliability.

[0058] 2. Data acquisition subsystem

[0059] Sensor Group:

[0060] Temperature sensor: The high-temperature flue gas section adopts K-type thermocouple (accuracy ±0.5% FS, temperature resistance 1300℃), and the SCO2 working fluid circuit adopts platinum resistance PT100 (accuracy ±0.1℃);

[0061] Pressure sensor: range 0-40MPa (accuracy ±0.25% FS), equipped with piezoresistive transmitter;

[0062] Flow sensor: The SCO2 circuit uses a Coriolis mass flowmeter (accuracy ±0.1%), and the LNG cooling energy pipeline uses a vortex flowmeter (accuracy ±0.5%);

[0063] Position sensor: The spiral partition angle is detected using an absolute encoder (resolution 0.1°, accuracy ±0.5°).

[0064] Data acquisition card: Advantech ADAM-6050 module, supports 16 analog inputs (16-bit ADC), sampling frequency 100Hz, meeting the needs of high-frequency real-time data acquisition.

[0065] 3. Execution drive subsystem

[0066] Spiral partition drive: servo motor (power 500W, torque 2.5N·m) with planetary gear reducer (reduction ratio 1:50), angle adjustment speed 0.5° / s, equipped with limit switch to prevent overtravel;

[0067] LNG cold energy exchanger valve: pneumatic butterfly valve (nominal diameter DN50), equipped with 4-20mA signal positioner (accuracy ±0.5% opening);

[0068] SCO2 circulating pump control: The frequency converter (ABB ACS580) adjusts the working fluid flow rate with a control accuracy of ±2% of the rated flow rate.

[0069] 4. Communication Network

[0070] Low-level communication: Modbus TCP / IP protocol is used to connect sensors and actuators. The backbone network is fiber-optic Ethernet (bandwidth 1Gbps), and the communication delay is less than 1ms.

[0071] Upper-layer interaction: Connects to the power plant supervisory control and data acquisition (SCADA) system via the OPC UA protocol, supporting remote parameter configuration and status monitoring.

[0072] A multivariable state space model was established that included the heat transfer characteristics of the spiral baffle, the thermodynamics of the SCO2 cycle, and the coupling of LNG cold energy. The state variables included:

[0073] Flue gas side: temperature Tg, flow rate Gg, spiral baffle angle θ;

[0074] Working fluid side: temperature Tc, pressure Pc, flow rate Gc;

[0075] Cold energy side: LNG vaporization volume mLNG, cold energy exchanger opening α;

[0076] Prediction algorithm: Model predictive control (MPC) combined with deep reinforcement learning (DRL) is used. The prediction time domain is updated every 50ms (prediction step size 10s, control step size 1s). The objective function is:

[0077] J=min(λ1ΔE+λ2ΔF+λ3ΔP)

[0078] Where: ΔE is the energy efficiency deviation, ΔF is the fuel consumption deviation, ΔP is the equipment stress deviation, and the weight coefficients λ1 = 0.6; λ2 = 0.3, and λ3 = 0.1.

[0079] Set the SCO2 cycle pressure upper limit to 30 MPa and the temperature lower limit to 20°C. When the limit is exceeded, the interlocking protection (such as cutting off the LNG cold energy supply and lowering the spiral partition angle) will be triggered.

[0080] The Bayesian network-based fault prediction model can diagnose abnormal conditions such as spiral partition jamming (identification rate 95%) and cold energy exchanger leakage (response time <2s) in real time.

[0081] The intelligent control system drives the adjustable spiral baffle of the first-stage waste heat boiler through a servo motor to change the flue gas flow cross-sectional area (adjustment angle 0-60°); and controls the working fluid flow of the SCO2 circulation system through a proportional valve (adjustment range 20-100% rated flow).

[0082] The intelligent control system controls the LNG gasification amount (corresponding to the cold energy supply of 0-100kW) through the gasifier regulating valve, and adjusts the proportion of SCO2 working fluid involved in cooling through the cold energy exchanger bypass valve (regulation accuracy ±5%).

[0083] The intelligent control system controls the angle of the spiral partition according to the load percentage (based on the maximum design load of the unit):

[0084] Full load (>80%): fixed angle 45°, giving priority to ensuring heat exchange efficiency;

[0085] Medium load (30%-80%): Use the extreme value search algorithm to search for the optimal angle every 30 seconds to stabilize the waste heat boiler outlet temperature at 350±5℃;

[0086] Low load (<30%): adjust the angle to 20° to reduce flue gas resistance and avoid turbine unit surge.

[0087] SCO2 loop parameter matching:

[0088] Working fluid flow control: According to the power demand of the turbine generator, the circulation pump speed is adjusted through the PID+feedforward compensation algorithm.

[0089] Pressure stability control: When the SCO2 pressure fluctuation is greater than ±1%, the bypass valve adjustment is started (response time <0.5s) to ensure that the turbine inlet pressure is stable at 25±0.2MPa.

[0090] Intelligent distribution of LNG cold energy: Prioritizes meeting the condensation needs of SCO2 working fluid (improving power generation efficiency), and the remaining cold energy is used to preheat boiler feed water (or supply industrial cooling loads).

[0091] Automatically adjust the valve opening according to the condensation temperature of the working medium

[0092] Peak and valley period control: During the low electricity price period (23:00-7:00), the battery is charged to 80% of the capacity of the energy storage battery; during the peak period (9:00-17:00), the discharge power does not exceed 60% of the rated capacity;

[0093] Waste heat storage linkage: When the outlet temperature of the tertiary condensate preheater is less than 45°C, the low-temperature waste heat is automatically switched to the phase change energy storage unit (energy storage efficiency ≥ 92%).

[0094] Storage stage: when the heat output of the waste heat recovery device (2) is greater than 15% of the system's immediate demand, the energy storage pump is started to inject the heat medium (thermal oil) into the phase change storage tank;

[0095] Release stage: The energy storage circuit valve is adjusted through the fuzzy control algorithm to make the condensate preheating temperature fluctuation less than ±2℃, ensuring the stability of boiler feed water.

[0096] Example 2

[0097] A method for recovering and utilizing waste heat from a gas-fired generator set according to an embodiment of the present invention comprises the following steps:

[0098] A. Waste Heat Collection: The waste heat recovery device 2 collects the high-temperature flue gas and component waste heat generated by the gas generator set 1. The high-temperature flue gas temperature is 800-1200°C, and the component waste heat temperature is 100-300°C. The high-temperature flue gas is introduced into the spiral baffle flue gas channel of the first-stage waste heat boiler 3;

[0099] B. Multi-stage heat exchange: High-temperature flue gas flows in the spiral baffle flue gas channel, exchanging heat with the wall, heating the SCO2 working medium to 300-400°C and a pressure of 20-30 MPa. The heated SCO2 working medium enters the secondary SCO2 circulation system 4 to drive the secondary SCO2 circulation system turbine unit to generate electricity. The low-temperature SCO2 working medium enters the tertiary condensate preheater 6 to preheat the condensate. The low-temperature SCO2 working medium temperature is 30-60°C.

[0100] C. LNG cold energy utilization: The intelligent control system 9 controls the opening of the cold energy exchanger of the LNG cold energy utilization module 7 according to the SCO2 cycle temperature parameters, injecting -162°C LNG cold energy into the working fluid circuit as needed to cool the SCO2 working fluid or other working fluids;

[0101] D. Energy Storage and Distribution: The electrical energy generated by the energy conversion device 5 is directly supplied to the electrical equipment, and the remaining electrical energy and recovered low-temperature heat energy are stored in the battery pack and phase change energy storage unit of the storage device 10 respectively;

[0102] E. Intelligent Control: The intelligent control module 8 adjusts the spiral baffle angle, SCO2 circulation flow rate and LNG cold energy supply in real time to keep the system's comprehensive energy efficiency ratio (PER) at 0.78-0.82.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be deemed to fall within the protection scope of the technical solution of the present invention.

Claims

1. A waste heat recovery system for a gas-fired generator set, characterized by: It comprises a gas generator set body (1), a waste heat recovery device (2), an energy conversion device (5), a storage device (10), an intelligent control module (8), a multi-stage heat exchange module, an LNG cold energy utilization module (7) and an intelligent control system (9); The gas generator set body (1) is connected to the waste heat recovery device (2); The multi-stage heat exchange module includes a first-stage waste heat boiler (3), a second-stage SCO2 circulation system (4) and a third-stage condensate preheater (6); The high-temperature flue gas output end of the waste heat recovery device (2) is connected to the flue gas channel inlet of the first-stage waste heat boiler (3), and the low-temperature waste heat output end is connected to the third-stage condensate preheater (6) or the storage device (10); the second-stage SCO2 circulation system (4) is connected to the first-stage waste heat boiler (3) and uses the SCO2 working medium for energy circulation; the third-stage condensate preheater (6) is connected to the low-temperature end of the second-stage SCO2 circulation system (4) for preheating condensate; the power input end of the energy conversion device (5) is connected to the turbine shaft of the second-stage SCO2 circulation system (4), and the power output end is connected to the battery pack of the storage device (10); the cold energy exchanger of the LNG cold energy utilization module (7) is connected in parallel to the working medium circuit of the second-stage SCO2 circulation system (4), and the cold energy supply end is connected to the actuator of the intelligent control system (9); The intelligent control module (8) is respectively connected to the gas generator set body (1), the waste heat recovery device (2), the energy conversion device (5), the storage device (10), the multi-stage heat exchange module, the LNG cold energy utilization module (7) and the intelligent control system (9), and is used to receive operating data and issue control instructions; The intelligent control system (9) is connected to the multi-stage heat exchange module and the LNG cold energy utilization module (7) and is used to control the heat exchange process and the cold energy utilization process.

2. A gas generator set waste heat recovery system according to claim 1, characterized in that: A spiral partition is provided inside the first-stage waste heat boiler (3) to divide the flue gas channel into spiral flow channels; The spiral partition is adjustable.

3. The waste heat recovery system for a gas-fired generator set according to claim 1, characterized in that: The adjustable spiral partition (31) is driven by a motor or a hydraulic drive device to achieve angle adjustment, with an adjustment range of 0°-60° and an accuracy of ±1°.

4. The waste heat recovery system for a gas-fired generator set according to claim 1, characterized in that: The LNG cold energy utilization module (7) comprises an LNG storage tank, a vaporizer and a cold energy exchanger, and is used to transfer the cold energy of the LNG to the SCO2 working medium.

5. The waste heat recovery system for a gas-fired generator set according to claim 1, characterized in that: The low-temperature waste heat collected by the waste heat recovery device (2) is directly connected to the storage device (10) or the three-stage condensed water preheater (6) for secondary utilization.

6. The waste heat recovery system for a gas-fired generator set according to claim 1, characterized in that: The storage device comprises a battery pack and a phase change energy storage unit, which are respectively used to store the electric energy generated by the energy conversion device (5) and the low-temperature heat energy collected by the waste heat recovery device (2).

7. The method for recovering and utilizing waste heat from a gas-fired generator set according to claim 1, characterized in that: The steps include: A. Waste heat collection: The waste heat recovery device (2) collects the high-temperature flue gas and component waste heat generated by the gas generator set body (1). The high-temperature flue gas temperature is 800-1200°C, and the component waste heat temperature is 100-300°C. The high-temperature flue gas is introduced into the spiral baffle flue gas channel of the first-stage waste heat boiler (3); B. Multi-stage heat exchange: The high-temperature flue gas flows in the spiral baffle flue gas channel and exchanges heat with the wall surface, heating the SCO2 working medium to 300-400℃ and a pressure of 20-30MPa; the heated SCO2 working medium enters the secondary SCO2 circulation system (4) to drive the secondary SCO2 circulation system turbine unit to generate electricity, and the low-temperature SCO2 working medium enters the third-stage condensate preheater (6) to preheat the condensate, and the low-temperature SCO2 working medium temperature is 30-60℃; C. LNG cold energy utilization: The intelligent control system (9) controls the opening of the cold energy exchanger of the LNG cold energy utilization module (7) according to the SCO2 cycle temperature parameters, injects -162°C LNG cold energy into the working fluid circuit as needed, and cools the SCO2 working fluid or other working fluids; D. Energy storage and distribution: The electric energy generated by the energy conversion device (5) is directly supplied to the electrical equipment, and the remaining electric energy and the recovered low-temperature heat energy are respectively stored in the battery pack and the phase change energy storage unit of the storage device (10); E. Intelligent regulation: The intelligent control module (8) adjusts the spiral baffle angle, SCO2 circulation flow and LNG cold energy supply in real time, and the system's comprehensive energy efficiency ratio is maintained at 0.78-0.82.

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