Coking waste heat cogeneration system and operation method coupled with multiple heterogeneous energy flows

Abstract

The present invention discloses a coking waste heat cogeneration system and operation method coupled with multiple heterogeneous energy flows. The system comprises: a waste heat collection system, a multi-heterogeneous energy flow reconstruction and comprehensive utilization system, and a thermal power station. The waste heat collection system comprises: a second heat pipe evaporator for recovering sensible waste heat from raw coal gas, a second gas-to-water heat exchanger for recovering waste heat from red coke, a high-pressure waste heat boiler and a medium-pressure waste heat boiler, and a first gas-to-water heat exchanger and a first heat pipe evaporator for recovering waste heat from flue gas. The multi-heterogeneous energy flow reconstruction and comprehensive utilization system comprises: a first double-effect lithium bromide absorption heat pump, a second double-effect lithium bromide absorption heat pump, medium- and low-pressure ejectors, a low-pressure ejector, a steam generator, a first water-to-water heat exchanger, a first single-effect lithium bromide absorption heat pump, a peak-shaving steam-to-water heat exchanger, and a large-capacity thermal storage module. The present invention optimizes and reconstructs the quality and quantity of the multiple heterogeneous energy flows, reduces irreversible losses in the waste heat utilization process, and improves waste heat utilization efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat pump systems, and in particular relates to a coking waste heat cogeneration system and an operation method thereof, coupled with multiple heterogeneous energy flows. Background Art

[0002] China's traditional coking process suffers from significant issues such as high energy consumption per unit of production capacity and low energy efficiency. Traditional waste heat recovery and utilization processes in the coking industry are relatively simple, isolated, and extensive, leading to energy supply and demand mismatches, significant irreversible losses in the waste heat utilization process, and low utilization efficiency of low-temperature thermal energy. Summary of the Invention

[0003] In response to the problems existing in the background technology, the present invention provides a coking waste heat cogeneration system coupled with multiple heterogeneous energy flows, which can comprehensively reconstruct and optimize the quality and quantity of multiple heterogeneous energy flows and efficiently and comprehensively utilize them in a cascaded manner, so as to reduce irreversible losses in the waste heat recovery and utilization process, improve the utilization efficiency of low-temperature waste heat, and promote the low-carbon development of the coking process. The system includes: a waste heat collection system, a multi-heterogeneous energy flow reconstruction and comprehensive utilization system, a primary heating network, a thermal power station, and a secondary heating network; wherein the waste heat collection system includes: a second heat pipe evaporator for recovering sensible waste heat of raw coal gas, a second gas-water heat exchanger for recovering waste heat of red coke, a high-pressure waste heat boiler and a medium-pressure waste heat boiler, and a first gas-water heat exchanger and a first heat pipe evaporator for recovering waste heat of flue gas;

[0004] The multi-heterogeneous energy flow reconstruction and comprehensive utilization system includes: a condenser, a closed cooling tower, a first double-effect lithium bromide absorption heat pump, a second double-effect lithium bromide absorption heat pump, medium and low pressure ejectors, a low pressure ejector, a steam generator, a first water-water heat exchanger, a first single-effect lithium bromide absorption heat pump, a peak-shaving steam-water heat exchanger and a large-capacity heat storage module, wherein the high-pressure steam outlet of the second heat pipe evaporator and the high-pressure waste heat boiler is connected to the main steam inlet of the steam turbine; the steam pipelines of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder of the steam turbine are connected in sequence, wherein the steam outlet of the high-pressure cylinder of the steam turbine is branched off and connected to the external medium-pressure steam pipeline for process; the steam outlet of the medium-pressure cylinder of the steam turbine is branched off and connected to the medium-pressure waste heat boiler and the first heat pipe evaporator. After the medium and low pressure steam outlets of the tube evaporator are merged, they are respectively connected to the working fluid steam inlet of the medium and low pressure ejector, the medium and low pressure steam inlet of the generator in the first double-effect lithium bromide absorption heat pump, and the medium and low pressure steam inlet of the generator in the second double-effect lithium bromide absorption heat pump; the mixed fluid outlet of the low pressure ejector is connected to the ejection fluid inlet of the medium and low pressure ejector, and the low pressure steam of 0.15 MPa at the mixed fluid outlet of the medium and low pressure ejector is respectively connected to the working fluid inlet of the low pressure ejector, the low pressure steam inlet of the generator of the first single-effect lithium bromide absorption heat pump, and the low pressure steam inlet of the peak shaving steam-water heat exchanger; the ultra-low pressure steam outlet of the steam generator is connected to the ejection fluid inlet of the low pressure ejector;

[0005] The medium- and high-temperature hot water side outlets of the first air-water heat exchanger and the second air-water heat exchanger are connected to the hot water inlet of the steam generator; the process low-temperature cooling water outlet is connected to the low-temperature water inlet of the evaporator of the first double-effect lithium bromide absorption heat pump; the evaporator low-temperature water outlet of the first double-effect lithium bromide absorption heat pump is connected to the process low-temperature cooling water inlet; the process high-temperature cooling water outlet is connected to the cooling water outlet of the first double-effect lithium bromide absorption heat pump and the cooling water outlet of the condenser after merging with the cooling water inlet of the closed cooling tower, the hot side circulating water inlet of the first water-water heat exchanger, the evaporator hot water inlet of the second double-effect lithium bromide absorption heat pump, and the evaporator hot water inlet of the first single-effect lithium bromide absorption heat pump;

[0006] The hot water outlet of the evaporator of the first single-effect lithium bromide absorption heat pump, the cooling water outlet of the closed cooling tower, the hot side circulating water outlet of the first water-water heat exchanger and the hot water outlet of the evaporator of the second double-effect lithium bromide absorption heat pump are respectively connected to the cooling water inlet of the condenser, the cooling water inlet of the first double-effect lithium bromide absorption heat pump and the high-temperature cooling water inlet for the process; the primary heat network return water pipeline is connected to the low-temperature side circulating water inlet of the first water-water heat exchanger and the low-temperature water pipeline of the large-capacity thermal storage module; the first The low-temperature side circulating water outlet of the water-water heat exchanger is connected to the primary water inlet of the absorber of the second double-effect lithium bromide absorption heat pump; the primary water outlet of the condenser of the second double-effect lithium bromide absorption heat pump is connected to the primary water inlet of the absorber of the first single-effect lithium bromide absorption heat pump; the primary water outlet of the condenser of the first single-effect lithium bromide absorption heat pump is connected to the primary water inlet of the peak-shaving steam-water heat exchanger; the primary water outlet of the peak-shaving steam-water heat exchanger is connected to the primary heating network water supply pipeline and the high-temperature water pipeline of the large-capacity thermal storage module;

[0007] The thermal power station includes: a second water-water heat exchanger, a first electric vapor compression heat pump and a second electric vapor compression heat pump with an ejector; wherein the first electric vapor compression heat pump includes: a first condenser, a first throttling device, a first compressor, and a high-pressure evaporator; the first compressor, the working fluid side of the first condenser, the first throttling device, the working fluid side of the high-pressure evaporator and the first compressor are connected in sequence to form a loop; the second electric vapor compression heat pump includes: a second condenser, a gas-gas ejector, a low-pressure evaporator, a second throttling device, a gas-liquid separator, and a second compressor; the second compressor, the working fluid side of the second condenser, the working fluid inlet of the ejector, the mixed fluid outlet of the ejector and the working fluid inlet of the gas-liquid separator, the gaseous working fluid outlet of the gas-liquid separator and the second compressor are connected in sequence to form a loop; the liquid working fluid outlet of the gas-liquid separator is connected to the ejector fluid inlet via the second throttling device and the working fluid side of the low-pressure evaporator in sequence.

[0008] The steam condensate outlet of the peak-shaving steam-water heat exchanger, the steam condensate outlet of the generator of the first single-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the second double-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the first double-effect lithium bromide absorption heat pump, the steam condensate outlet of the steam generator and the steam condensate outlet of the condenser are connected to the condensate inlet of the condensate tank after merging;

[0009] The condensate outlet of the condensate tank is respectively connected to the condensate side inlet of the first gas-water heat exchanger, the condensate inlet of the first heat pipe evaporator, the water side inlet of the second gas-water heat exchanger, the condensate inlet of the medium-pressure waste heat boiler, the condensate inlet of the high-pressure waste heat boiler and the condensate inlet of the second heat pipe evaporator in the waste heat collection system through a condensate pump.

[0010] The second heat pipe evaporator recovers the sensible heat of the raw gas in the temperature range of 450-800°C to produce 5.1-5.3MPa high-pressure steam;

[0011] The high-pressure waste heat boiler recovers the heat of the high-temperature inert gas N2 to produce 5.1-5.3 MPa high-pressure steam; the medium-pressure waste heat boiler recovers the heat of the medium-temperature inert gas N2 to produce 0.3 MPa medium-low-pressure steam; the second gas-water heat exchanger is used to recover the heat of the medium-low temperature inert gas N2 to produce medium-high-temperature hot water of 85-90°C; the high-temperature inert gas N2, the medium-temperature inert gas N2 and the medium-low temperature inert gas N2 are all recovered from the coke quenching drum;

[0012] The first heat pipe evaporator recovers waste heat from flue gas in the medium temperature range to produce 0.3MPa steam; the first gas-water heat exchanger recovers waste heat from flue gas in the medium and low temperature range to produce medium and high temperature hot water of 85-90°C.

[0013] Provided is an operating method for a coking waste heat cogeneration system based on multi-heterogeneous energy flow coupling. High-pressure steam from the second heat pipe evaporator and the high-pressure waste heat boiler enters the high-pressure cylinder of the steam turbine to expand and perform work, becoming 1.0 MPa medium-pressure steam; a portion of the medium-pressure steam from the high-pressure cylinder of the steam turbine enters the medium-pressure steam pipeline for the process, and another portion of the medium-pressure steam enters the medium-pressure cylinder of the steam turbine to continue expanding and perform work, becoming 0.3 MPa medium-low-pressure steam; a portion of the medium-low-pressure steam from the medium-pressure cylinder of the steam turbine is mixed with the medium-low-pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator, and another portion of the medium-low-pressure steam enters the low-pressure cylinder of the steam turbine to continue expanding and perform work, becoming exhaust steam and entering the condenser to be cooled into condensate; the mechanical energy output by the steam turbine drives the generator to generate electricity; the generated electricity is first supplied to the coking process through the power transmission and distribution system, and can be connected to the municipal power grid only when there is sufficient electricity.

[0014] The medium- and low-pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator is first mixed with part of the medium- and low-pressure steam from the medium-pressure cylinder of the steam turbine, and then divided into three paths: the first path is used as a working fluid to drive the medium- and low-pressure ejector to inject the steam from the low-pressure ejector and convert it into 0.15MPa low-pressure steam at the outlet of the medium- and low-pressure ejector mixing chamber; the second path is used as a driving heat source to drive the first double-effect lithium bromide absorption heat pump to recover the low-temperature cooling waste heat from the coking plant; the third path is used as a driving heat source to drive the second double-effect lithium bromide absorption heat pump to recover and utilize the medium- and low-temperature waste heat;

[0015] The mixed fluid from the medium and low pressure ejectors is divided into three paths. The first path is used as the working fluid to drive the low pressure ejector to eject ultra-low pressure steam from the steam generator; the second path is used as the driving heat source to drive the first single-effect lithium bromide absorption heat pump to recover medium and low temperature waste heat and heat the primary heat network circulating water; the third path is used as the heating heat source to enter the peak-shaving steam-water heat exchanger to further heat the primary heat network circulating water.

[0016] The medium-high temperature hot water of 85-90℃ from the first and second gas-water heat exchangers first enters the steam generator to generate ultra-low pressure steam, which then enters the low-pressure ejector as the ejector fluid.

[0017] The low-temperature cooling water for the process enters the first double-effect lithium bromide absorption heat pump, where its water temperature is reduced from 23°C to 16°C, and at the same time the cooling water is heated from 30°C to 40°C;

[0018] The 40°C cooling water from the first double-effect lithium bromide absorption heat pump is combined with the 40°C cooling water for the process and the 40°C cooling water from the condenser, and then divided into four routes. The first route can enter the closed cooling tower when sufficient waste heat is available and be cooled to 30°C. The second, third, and fourth routes enter the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, and the first single-effect lithium bromide absorption heat pump, respectively, and are recycled and used to heat the circulating water of the primary heat network.

[0019] The condensate from the peak-shaving steam-water heat exchanger, the first single-effect lithium bromide absorption heat pump, the second double-effect lithium bromide absorption heat pump, the first water-water heat exchanger and the first double-effect lithium bromide absorption heat pump is first collected and enters the condensate tank, and then supplied to the heat extraction thermal equipment in the waste heat collection system through the condensate pump;

[0020] The return water from the primary heat network enters the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump and the peak-shaving steam-water heat exchanger in sequence and is heated and heated step by step.

[0021] The first double-effect lithium bromide absorption heat pump is continuously turned on;

[0022] When the heat load increases from small to large, the second water-water heat exchanger in the thermal power station is put into operation at full load during the entire heating period; the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the large-capacity heat storage module and the peak-shaving steam-water heat exchanger in the heat source station can be put into operation step by step according to the increase in heat load; if the heat load demand increases further, the thermal power station will then put into operation the first electric vapor compression heat pump and the second vapor compression heat pump with ejector in sequence.

[0023] The first double-effect lithium bromide absorption heat pump is continuously turned on;

[0024] When the heat load changes from small to large, the first water-water heat exchanger and the second double-effect lithium bromide absorption heat pump of the heat source station will operate at full load during the entire heating period, and the second water-water heat exchanger, the first vapor compression heat pump and the second vapor compression heat pump with ejector of the thermal power station will be put into operation in sequence; the load of the electric vapor compression heat pump will all be operated from small to large; if the heat load demand continues to increase, the heat source station will first put into operation the first single-effect lithium bromide absorption heat pump, and then put into operation the large-capacity heat storage module and the peak-shaving steam-water heat exchanger.

[0025] Another coking waste heat cogeneration system with multiple heterogeneous energy flows coupled is also provided, comprising: a waste heat collection system, a multiple heterogeneous energy flow reconstruction and comprehensive utilization system, a primary heating network, a thermal power station, and a secondary heating network; wherein the waste heat collection system comprises: a second heat pipe evaporator for recovering sensible waste heat from raw coal gas, a second gas-water heat exchanger for recovering waste heat from red coke, a high-pressure waste heat boiler and a medium-pressure waste heat boiler, and a first gas-water heat exchanger and a first heat pipe evaporator for recovering waste heat from flue gas;

[0026] The multi-heterogeneous energy flow reconstruction and comprehensive utilization system includes: a low-pressure steam-water heat exchanger, a condenser, a closed cooling tower, a first double-effect lithium bromide absorption heat pump, a second double-effect lithium bromide absorption heat pump, a medium- and low-pressure ejector, a low-pressure ejector, a steam generator, a first water-water heat exchanger, a first single-effect lithium bromide absorption heat pump, a peak-shaving steam-water heat exchanger and a large-capacity heat storage module, wherein the high-pressure steam outlet of the second heat pipe evaporator and the high-pressure waste heat boiler is connected to the main steam inlet of the steam turbine; the steam pipelines of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder of the steam turbine are connected in sequence, wherein the steam outlet of the high-pressure cylinder of the steam turbine branches off and is connected to an external medium-pressure steam pipeline for process; the steam outlet of the medium-pressure cylinder of the steam turbine branches off and is connected to the medium-pressure waste heat boiler and the first heat pipe evaporator. After the medium and low pressure steam outlets of 0.3MPa are merged, they are respectively connected to the working fluid steam inlet of the medium and low pressure ejector, the medium and low pressure steam inlet of the peak shaving steam-water heat exchanger, the medium and low pressure steam inlet of the generator in the first double-effect lithium bromide absorption heat pump and the medium and low pressure steam inlet of the generator in the second double-effect lithium bromide absorption heat pump; the mixed fluid outlet of the low pressure ejector is connected to the ejection fluid inlet of the medium and low pressure ejector, and the low pressure steam of 0.15MPa at the mixed fluid outlet of the medium and low pressure ejector is respectively connected to the working fluid inlet of the low pressure ejector, the low pressure steam inlet of the generator of the first single effect lithium bromide absorption heat pump and the low pressure steam inlet of the low pressure steam-water heat exchanger; the ultra-low pressure steam outlet of the steam generator is connected to the ejection fluid inlet of the low pressure ejector;

[0027] The medium and high temperature hot water outlets of the first air-water heat exchanger and the second air-water heat exchanger are connected to the hot water inlet of the steam generator; the process low temperature cooling water outlet is connected to the low temperature water inlet of the evaporator of the first double-effect lithium bromide absorption heat pump; the low temperature water outlet of the evaporator of the first double-effect lithium bromide absorption heat pump is connected to the process low temperature cooling water inlet; the process high temperature cooling water outlet is connected to the cooling water outlet of the first double-effect lithium bromide absorption heat pump and the cooling water outlet of the condenser after merging with the cooling water inlet of the closed cooling tower, the first water-water exchanger and the cooling water outlet of the condenser. The hot side circulating water inlet of the heat exchanger, the evaporator hot water inlet of the second double-effect lithium bromide absorption heat pump and the evaporator hot water inlet of the first single-effect lithium bromide absorption heat pump are connected; the evaporator hot water outlet of the first single-effect lithium bromide absorption heat pump, the cooling water outlet of the closed cooling tower, the hot side circulating water outlet of the first water-water heat exchanger and the evaporator hot water outlet of the second double-effect lithium bromide absorption heat pump are merged and respectively connected to the cooling water inlet of the condenser, the cooling water inlet of the first double-effect lithium bromide absorption heat pump and the high-temperature cooling water inlet for the process;

[0028] The return water pipeline of the primary heat network is connected to the low-temperature side circulating water inlet of the first water-water heat exchanger and the low-temperature water pipeline of the large-capacity heat storage module; the low-temperature side circulating water outlet of the first water-water heat exchanger is connected to the primary water inlet of the absorber of the second double-effect lithium bromide absorption heat pump; the condenser primary water outlet of the second double-effect lithium bromide absorption heat pump is connected to the absorber primary water inlet of the first single-effect lithium bromide absorption heat pump; the condenser primary water outlet of the first single-effect lithium bromide absorption heat pump is connected to the primary water inlet of the low-pressure steam-water heat exchanger; the primary water outlet of the low-pressure steam-water heat exchanger is connected to the primary water inlet of the peak-shaving steam-water heat exchanger; the primary water outlet of the peak-shaving steam-water heat exchanger is connected to the primary heat network water supply pipeline and the high-temperature water pipeline of the large-capacity heat storage module.

[0029] The thermal power station includes: a single-effect lithium bromide absorption heat pump of the thermal power station, a semi-effect lithium bromide absorption heat pump and a third water-water heat exchanger; wherein, the single-effect lithium bromide absorption heat pump of the thermal power station mainly includes: a generator, a third condenser, a solution heat exchanger, an absorber and a third evaporator; the semi-effect lithium bromide absorption heat pump mainly includes: a high-pressure generator, a low-pressure generator, a fourth condenser, a high-temperature solution heat exchanger, a low-temperature solution heat exchanger, a high-pressure absorber, a low-pressure absorber and a fourth evaporator; wherein, the primary heat network water supply pipeline is connected to the inlet of the primary water side of the generator of the single-effect lithium bromide absorption heat pump of the thermal power station; the outlet of the primary water side of the generator of the single-effect lithium bromide absorption heat pump of the thermal power station is connected to the high-pressure generator of the semi-effect lithium bromide absorption heat pump The inlet of the primary water side is connected; the outlet of the primary water side of the high-pressure generator of the semi-effect lithium bromide absorption heat pump is connected to the inlet of the primary water side of the low-pressure generator of the semi-effect lithium bromide absorption heat pump; the outlet of the primary water side of the low-pressure generator of the semi-effect lithium bromide absorption heat pump is connected to the inlet of the primary water side of the third water-water heat exchanger; the outlet of the primary water side of the third water-water heat exchanger is connected to the inlet of the primary water side of the third evaporator of the single-effect lithium bromide absorption heat pump of the thermal power station; the outlet of the primary water side of the third evaporator of the single-effect lithium bromide absorption heat pump of the thermal power station is connected to the inlet of the primary water side of the fourth evaporator of the semi-effect lithium bromide absorption heat pump; the outlet of the primary water side of the fourth evaporator of the semi-effect lithium bromide absorption heat pump is connected to the return water pipe of the primary heating network;

[0030] The return water pipeline of the secondary heat network is divided into three routes, which are respectively connected to the inlet of the secondary water side of the third water-water heat exchanger, the inlet of the secondary water side of the first absorber in the single-effect lithium bromide absorption heat pump of the thermal power station, and the inlet of the secondary water side of the low-pressure absorber in the semi-effect lithium bromide absorption heat pump; the outlet of the secondary water side of the third water-water heat exchanger is connected to the secondary heat network water supply pipeline, the outlet of the secondary water side of the first absorber is connected to the secondary heat network water supply pipeline after absorbing heat through the secondary water side of the third condenser, and the outlet of the secondary water side of the low-pressure absorber is connected to the secondary heat network water supply pipeline after absorbing heat through the secondary water side of the high-pressure absorber and the secondary water side of the fourth condenser.

[0031] The steam condensate outlet of the peak-shaving steam-water heat exchanger, the steam condensate outlet of the low-pressure steam-water heat exchanger, the steam condensate outlet of the generator of the first single-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the second double-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the first double-effect lithium bromide absorption heat pump, the steam condensate outlet of the steam generator and the steam condensate outlet of the condenser are connected to the condensate inlet of the condensate tank after merging;

[0032] The condensate outlet of the condensate tank is respectively connected to the condensate side inlet of the first air-water heat exchanger, the water side inlet of the second air-water heat exchanger, the condensate inlet of the first heat pipe evaporator, the condensate inlet of the medium-pressure waste heat boiler, the condensate inlet of the high-pressure waste heat boiler and the condensate inlet of the second heat pipe evaporator in the waste heat collection system through a condensate pump.

[0033] The second heat pipe evaporator recovers the sensible heat of the raw gas in the temperature range of 450-800°C to produce 5.1-5.3MPa high-pressure steam;

[0034] The high-pressure waste heat boiler recovers the heat of the high-temperature inert gas N2 to produce 5.1-5.3 MPa high-pressure steam; the medium-pressure waste heat boiler recovers the heat of the medium-temperature inert gas N2 to produce 0.3 MPa medium-low-pressure steam; the second gas-water heat exchanger is used to recover the heat of the medium-low temperature inert gas N2 to produce medium-high-temperature hot water of 85-90°C; the high-temperature inert gas N2, the medium-temperature inert gas N2 and the medium-low temperature inert gas N2 are all recovered from the coke quenching drum;

[0035] The first heat pipe evaporator recovers waste heat from flue gas in the medium temperature range to produce 0.3MPa steam; the first gas-water heat exchanger recovers waste heat from flue gas in the medium and low temperature range to produce medium and high temperature hot water of 85-90°C.

[0036] Also provided is another operation method of a coking waste heat cogeneration system based on multi-heterogeneous energy flow coupling, wherein 5.1-5.3 MPa high-pressure steam from the second heat pipe evaporator and the high-pressure waste heat boiler enters the high-pressure cylinder of the steam turbine for expansion and work, and then becomes 1.0 MPa medium-pressure steam; the medium-pressure steam is divided into two paths, one path of medium-pressure steam enters the process medium-pressure steam pipeline, and the other path of medium-pressure steam enters the medium-pressure cylinder of the steam turbine for further expansion and work, and then becomes 0.3 MPa medium-low pressure steam; the medium-low pressure steam is divided into two paths, one path of medium-low pressure steam enters the low-pressure cylinder of the steam turbine for further expansion and work, and then becomes exhaust steam and enters the condenser to be cooled into condensate; the other path of medium-low pressure steam is used as heat extraction steam and mixed with the medium-low pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator;

[0037] The 0.3MPa medium- and low-pressure steam is divided into four paths. The first path serves as a working fluid to enter the medium- and low-pressure ejector to eject the steam from the low-pressure ejector and become 0.15MPa low-pressure steam. The second path serves as a driving heat source to drive the first double-effect lithium bromide absorption heat pump to recover the waste heat of the process low-temperature cooling water. The third path serves as a driving heat source to drive the second double-effect lithium bromide absorption heat pump to recover and utilize the low-temperature waste heat and heat the primary heat network circulating water. The fourth path serves as a heating heat source to enter the peak-shaving medium- and low-pressure steam-water heat exchanger to heat the primary heat network circulating water.

[0038] The 0.15MPa low-pressure steam from the medium and low-pressure ejectors is divided into three paths. The first path enters the low-pressure ejector as a working fluid, ejecting ultra-low-pressure steam from the steam generator; the second path enters the first single-effect lithium bromide absorption heat pump as a driving heat source, recovering low-temperature waste heat and heating the primary heat network circulating water; the third path enters the low-pressure steam-water heat exchanger as a heating heat source, heating the primary heat network circulating water;

[0039] The medium-high-temperature hot water of 85-90°C from the first and second gas-water heat exchangers enters the steam generator, generating ultra-low-pressure steam, which is used as the injection fluid for the low-pressure ejector. The medium-low-pressure ejector, driven by the medium-low-pressure steam, ejects the mixed fluid from the low-pressure ejector to produce 0.15MPa low-pressure steam.

[0040] The low-temperature cooling water for the process enters the first double-effect lithium bromide absorption heat pump, and the temperature is reduced from 23°C to 16°C;

[0041] The circulating cooling water from the first double-effect lithium bromide absorption heat pump, the circulating cooling water from the condenser and the high-temperature cooling water for the process are combined and then enter the first water-water heat exchanger, the evaporator of the second double-effect lithium bromide absorption heat pump, the evaporator of the first single-effect lithium bromide absorption heat pump and the closed cooling tower in parallel to release heat and cool down;

[0042] The condensate from the peak-shaving medium- and low-pressure steam-water heat exchangers, the low-pressure steam-water heat exchanger, the first single-effect lithium bromide absorption heat pump, the second double-effect lithium bromide absorption heat pump, the condenser, and the first double-effect lithium bromide absorption heat pump is combined and enters the condensate tank; the condensate from the condensate tank enters the first gas-water heat exchanger, the first heat pipe evaporator, the second gas-water heat exchanger, the medium-pressure waste heat boiler, the high-pressure waste heat boiler, and the second heat pipe evaporator in the waste heat collection system in parallel under the action of the condensate pump;

[0043] The return water from the primary heating network enters the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the low-pressure steam-water heat exchanger, and the peak-shaving medium- and low-pressure steam-water heat exchanger in sequence, and is heated and heated step by step. When the heating capacity of the multi-heterogeneous energy flow reconstruction and comprehensive utilization system is greater than the heat load demand, the large-capacity heat storage module stores heat; when the heating capacity of the multi-heterogeneous energy flow reconstruction and comprehensive utilization system is less than the heat load demand, the large-capacity heat storage module releases heat.

[0044] The primary heat network water first serves as a driving heat source and enters the single-effect lithium bromide absorption heat pump and the semi-effect lithium bromide absorption heat pump of the thermal power station in sequence; then, it serves as a heating heat source and enters the third water-water heat exchanger; finally, it serves as a low-temperature heat source and enters the third evaporator of the second single-effect lithium bromide absorption heat pump and the fourth evaporator of the semi-effect lithium bromide absorption heat pump in sequence; the secondary heat network return water is divided into three paths and connected in parallel to enter the third water-water heat exchanger, the second single-effect lithium bromide absorption heat pump, and the semi-effect lithium bromide absorption heat pump, where it is heated and then merged; then, it serves as secondary water supply and enters the secondary heat network water supply pipeline;

[0045] The first double-effect lithium bromide absorption heat pump is on all year round;

[0046] When the heat load changes from small to large, the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the large-capacity heat storage module, and the low-pressure steam-water heat exchanger of the heat source station are put into operation in sequence.

[0047] The beneficial effects of the present invention are:

[0048] 1. A cascade collection method is adopted to achieve in-depth collection of waste heat from the coking process, improve the energy utilization efficiency of the coking process, and reduce the carbon emissions per unit production capacity of the coking process.

[0049] 2. Optimize and reconstruct the quality and quantity of multiple heterogeneous energy flows, transform disordered energy flows into orderly ones, reduce irreversible losses in the waste heat utilization process, achieve coordinated cascade, efficient, and comprehensive deep utilization of multiple-grade complex energy flows, improve waste heat utilization efficiency, and meet the low-loss exergy heating requirements of the primary heat network circulating water cascade.

[0050] 3. Through the cogeneration of coking waste heat by coupling multiple heterogeneous energy flows, the power and heat self-sufficiency of the coking process can be improved, energy conservation and emission reduction can be achieved, and the pollution of the coking process to the surrounding atmospheric environment can be reduced.

[0051] 4. A waste heat utilization method for low-temperature heating, which not only introduces a steam turbine into the reconstruction and optimization of the coking waste heat energy flow, but also fully utilizes steam.

[0052] 5. Two air-water heat exchangers are added to produce medium- and high-temperature hot water, which is then fed into the steam generator to generate ultra-low-pressure steam for the injection fluid of the low-pressure ejector.

[0053] 6. A hybrid ejector is used to convert low-temperature hot water of 80-95°C into 0.15MPa steam to drive a single-effect lithium bromide absorption heat pump. The single-effect lithium bromide absorption heat pump can also be used for low-temperature waste heat, while reducing the irreversible losses caused by directly heating low-temperature hot water in the hot water network with medium- and low-pressure steam of 0.3MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a system schematic diagram of a heat source station in Example 1 of a coking waste heat cogeneration system and operation method coupled with multiple heterogeneous energy flows of the present invention.

[0055] Figure 2 This is a system diagram of a thermal power station in Example 1 of the present invention.

[0056] Figure 3 This is a system schematic diagram of the heat source station in Example 2 of the present invention.

[0057] Figure 4 This is a system diagram of a thermal power station in the second embodiment of the present invention. DETAILED DESCRIPTION

[0058] The present invention will be further described in detail below with reference to the accompanying drawings.

[0059] like Figure 1 and Figure 2 The first embodiment shown includes: a waste heat collection system, a multi-heterogeneous energy flow reconstruction and comprehensive utilization system, a power transmission and distribution system, a primary heating network, a thermal power station, and a secondary heating network. The waste heat collection system utilizes a process to deeply collect waste heat from raw coal gas, red coke, and flue gas. The collected waste heat is efficiently and comprehensively utilized in the multi-heterogeneous energy flow reconstruction and comprehensive utilization system to achieve cogeneration of heat and power.

[0060] The multi-heterogeneous energy flow reconstruction and comprehensive utilization system includes: a steam turbine, a generator, a condenser, a closed cooling tower, a first double-effect lithium bromide absorption heat pump, a second double-effect lithium bromide absorption heat pump, medium and low pressure ejectors, a low pressure ejector, a steam generator, a first water-water heat exchanger, a first single-effect lithium bromide absorption heat pump, a peak-shaving steam-water heat exchanger and a large-capacity heat storage module, wherein the high-pressure steam outlet of the second heat pipe evaporator and the high-pressure waste heat boiler is connected to the main steam inlet of the steam turbine; the steam pipelines of the high-pressure cylinder, medium-pressure cylinder and low-pressure cylinder of the steam turbine are connected in sequence, wherein the steam outlet of the high-pressure cylinder of the steam turbine is branched off and connected to the external medium-pressure steam pipeline for process; the steam outlet of the medium-pressure cylinder of the steam turbine is branched off and connected to the medium-pressure waste heat boiler and the medium- and low-pressure steam of the first heat pipe evaporator. After the steam outlets are merged (0.3MPa), they are respectively connected to the working fluid steam inlets of the medium and low pressure ejectors, the medium and low pressure steam inlets of the generator in the first double-effect lithium bromide absorption heat pump, and the medium and low pressure steam inlets of the generator in the second double-effect lithium bromide absorption heat pump; the mixed fluid outlet of the low pressure ejector is connected to the induced fluid inlet of the medium and low pressure ejector, and the mixed fluid outlet of the medium and low pressure ejector (0.15MPa low pressure steam) is respectively connected to the working fluid inlet of the low pressure ejector, the low pressure steam inlet of the generator of the first single effect lithium bromide absorption heat pump, and the low pressure steam inlet of the peak shaving steam-water heat exchanger; the ultra-low pressure steam outlet of the steam generator is connected to the induced fluid inlet of the low pressure ejector; the main shaft of the steam turbine drives the generator to be connected to the power transmission and distribution system;

[0061] The medium- and high-temperature hot water outlets (85-90°C) of the first and second air-water heat exchangers are connected to the hot water inlet of the steam generator; the process low-temperature cooling water outlet (23°C) is connected to the evaporator low-temperature water inlet of the first double-effect lithium bromide absorption heat pump; and the evaporator low-temperature water outlet of the first double-effect lithium bromide absorption heat pump is connected to the process low-temperature cooling water inlet (16°C);

[0062] The high-temperature cooling water outlet (40°C) for the process is merged with the cooling water outlet of the first double-effect lithium bromide absorption heat pump and the cooling water outlet of the condenser, and then connected to the cooling water inlet of the closed cooling tower, the hot side circulating water inlet of the first water-water heat exchanger, the evaporator hot water inlet of the second double-effect lithium bromide absorption heat pump, and the evaporator hot water inlet of the first single-effect lithium bromide absorption heat pump respectively;

[0063] The evaporator hot water outlet of the first single-effect lithium bromide absorption heat pump, the cooling water outlet of the closed cooling tower, the hot side circulating water outlet of the first water-water heat exchanger and the evaporator hot water outlet of the second double-effect lithium bromide absorption heat pump are respectively connected to the cooling water inlet of the condenser, the cooling water inlet of the first double-effect lithium bromide absorption heat pump and the high-temperature cooling water inlet for the process; the steam condensate outlet of the peak-shaving steam-water heat exchanger, the steam condensate outlet of the generator of the first single-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the second double-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the first double-effect lithium bromide absorption heat pump, the steam condensate outlet of the steam generator and the steam condensate outlet of the condenser are connected to the condensate inlet of the condensate tank after merging;

[0064] The condensate outlet of the condensate tank is connected to the condensate side inlet of the first gas-water heat exchanger, the condensate inlet of the first heat pipe evaporator, the water side inlet of the second gas-water heat exchanger, the condensate inlet of the medium-pressure waste heat boiler, the condensate inlet of the high-pressure waste heat boiler, and the condensate inlet of the second heat pipe evaporator in the waste heat collection system through a condensate pump;

[0065] The return water pipeline of the primary heat network is connected to the low-temperature side circulating water inlet of the first water-water heat exchanger and the low-temperature water pipeline of the large-capacity heat storage module; the low-temperature side circulating water outlet of the first water-water heat exchanger is connected to the primary water inlet of the absorber of the second double-effect lithium bromide absorption heat pump; the primary water outlet of the condenser of the second double-effect lithium bromide absorption heat pump is connected to the primary water inlet of the absorber of the first single-effect lithium bromide absorption heat pump; the primary water outlet of the condenser of the first single-effect lithium bromide absorption heat pump is connected to the primary water inlet of the peak-shaving steam-water heat exchanger; the primary water outlet of the peak-shaving steam-water heat exchanger is connected to the water supply pipeline of the primary heat network and the high-temperature water pipeline of the large-capacity heat storage module.

[0066] like Figure 1 The waste heat collection system shown includes: a first heat pipe evaporator, a second heat pipe evaporator, a high-pressure waste heat boiler, a medium-pressure waste heat boiler, a first air-water heat exchanger, and a second air-water heat exchanger. The specific waste heat depth collection method of the waste heat collection system is as follows:

[0067] For the sensible waste heat from raw coal gas, a second heat pipe evaporator is used to recover this waste heat in the temperature range of 450-800°C, producing 5.1-5.3 MPa high-pressure steam. For the waste heat from red coke, low-temperature inert gas N2 is first used in the quenching drum to deeply recover the waste heat from the red coke in the temperature range of 90-1000°C, producing 850-950°C inert gas N2. Secondly, a high-pressure waste heat boiler is used to recover the heat from the high-temperature inert gas N2, producing 5.1-5.3 MPa high-pressure steam. Finally, a medium-pressure waste heat boiler is used to recover the heat from the medium-temperature inert gas N2, producing 0.3 MPa medium-low-pressure steam. Finally, a second gas-to-water heat exchanger is used to recover the heat from the medium-low-temperature inert gas N2, producing 85-90°C medium-high-temperature hot water. This achieves tiered and deep collection of the waste heat from red coke. For waste heat from flue gas, the first heat pipe evaporator is used to recover waste heat from the medium-temperature range of flue gas, producing 0.3MPa steam. Then, the first air-water heat exchanger is used to recover waste heat from the medium- and low-temperature range of flue gas, producing medium- and high-temperature hot water at 85-90°C. This achieves a tiered, deep collection of waste heat from flue gas. This tiered, deep collection method produces a variety of energy flows of varying sizes and qualities.

[0068] like Figure 2 The thermal power station of the illustrated embodiment 1 is a low-temperature compression heat exchange unit, comprising: a second water-water heat exchanger, a first electric vapor compression heat pump, and a second electric vapor compression heat pump with an ejector;

[0069] The first electric vapor compression heat pump comprises: a first condenser, a first throttling device, a first compressor, and a high-pressure evaporator; the first compressor, the working fluid side of the first condenser, the first throttling device, the working fluid side of the high-pressure evaporator, and the first compressor are sequentially connected to form a loop;

[0070] A second electric vapor compression heat pump with an ejector includes: a second condenser, a gas-gas ejector, a low-pressure evaporator, a second throttling device, a gas-liquid separator, and a second compressor; the second compressor, the working fluid side of the second condenser, the working fluid inlet of the ejector, the mixed fluid outlet of the ejector, the working fluid inlet of the gas-liquid separator, the gaseous working fluid outlet of the gas-liquid separator, and the second compressor are sequentially connected to form a circuit; the liquid working fluid outlet of the gas-liquid separator is sequentially connected to the ejector fluid inlet of the ejector via the second throttling device and the working fluid side of the low-pressure evaporator;

[0071] After the primary supply water (80℃) enters the thermal power station, it releases heat in sequence through the hot side of the water-water heat exchanger, the water side of the high-pressure evaporator, and the water side of the low-pressure evaporator before flowing out as primary return water (20℃);

[0072] After entering the thermal power station, the secondary return water (40℃) enters the water side of the first condenser, the water side of the second condenser, and the water side of the second water-water heat exchanger, absorbs heat, and then merges and flows out as secondary supply water (50℃);

[0073] In operation mode 1 of embodiment 1, steam heating is used first when the heat load increases from small to large; the design temperature of the primary supply / return water is 80°C / 20°C, and the design temperature of the secondary supply / return water is 50°C / 40°C.

[0074] High-pressure steam utilization: High-pressure steam from the second heat pipe evaporator and the high-pressure waste heat boiler enters the high-pressure cylinder of the steam turbine, where it expands and produces work, becoming 1.0 MPa medium-pressure steam. A portion of the medium-pressure steam from the turbine's high-pressure cylinder enters the process medium-pressure steam pipeline, while another portion enters the turbine's intermediate-pressure cylinder for further expansion and production, becoming 0.3 MPa medium-low-pressure steam. A portion of the medium-low-pressure steam from the turbine's intermediate-pressure cylinder is mixed with the medium-low-pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator. Another portion enters the turbine's low-pressure cylinder for further expansion and production, becoming exhaust steam and entering the condenser, where it is cooled and converted into condensate. The mechanical energy output by the turbine drives the generator to generate electricity. The generated electricity is first supplied to the coking process through the power transmission and distribution system, and then connected to the municipal power grid when sufficient power is available.

[0075] Medium- and low-pressure steam utilization method: The medium- and low-pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator is first mixed with some medium- and low-pressure steam from the turbine's intermediate-pressure cylinder. The steam is then divided into three paths: the first path serves as the working fluid to drive the medium- and low-pressure ejector, ejecting steam from the low-pressure ejector. This steam is converted to 0.15 MPa low-pressure steam at the outlet of the medium- and low-pressure ejector mixing chamber. The second path serves as the driving heat source to drive the first double-effect lithium bromide absorption heat pump to recover low-temperature waste heat from the coking plant. The third path serves as the driving heat source to drive the second double-effect lithium bromide absorption heat pump to recover medium- and low-temperature waste heat. During the heating period, low-temperature heat is prioritized, specifically by using medium- and low-pressure steam to drive the lithium bromide absorption heat pump to recover low-temperature waste heat. This medium- and low-temperature steam is primarily sourced from the medium- and low-pressure boilers, serving as a supplementary regulator for turbine startup.

[0076] Low-pressure steam utilization method: The mixed fluid from the medium and low-pressure ejectors is divided into three paths. The first path is used as the working fluid to drive the low-pressure ejector to eject ultra-low-pressure steam from the steam generator; the second path is used as the driving heat source to drive the first single-effect lithium bromide absorption heat pump to recover medium and low-temperature waste heat and heat the primary heat network circulating water; the third path is used as the heating heat source to enter the peak-shaving steam-water heat exchanger to further heat the primary heat network circulating water.

[0077] Method for utilizing medium and high temperature hot water: The medium and high temperature hot water of 85-90°C from the first gas-water heat exchanger and the second gas-water heat exchanger first enters the steam generator to generate ultra-low pressure steam, and then enters the low-pressure ejector as the injection fluid.

[0078] Low-temperature cooling water utilization method: The low-temperature cooling water for the process enters the first double-effect lithium bromide absorption heat pump, and its water temperature is reduced from 23°C to 16°C. At the same time, the cooling water is heated from 30°C to 40°C.

[0079] High-temperature cooling water utilization method: The 40°C cooling water from the first double-effect lithium bromide absorption heat pump is combined with the 40°C cooling water for the process and the 40°C cooling water for the condenser, and then divided into four paths. The first path can enter the closed cooling tower when there is sufficient waste heat utilization, and be cooled to 30°C; the second, third and fourth paths respectively enter the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, and the first single-effect lithium bromide absorption heat pump, and are recycled and used to heat the primary heat network circulating water.

[0080] Condensate utilization method: The condensate from the peak-shaving steam-water heat exchanger, the first single-effect lithium bromide absorption heat pump, the second double-effect lithium bromide absorption heat pump, the first water-water heat exchanger and the first double-effect lithium bromide absorption heat pump is first collected and enters the condensate tank, and then supplied to the heat extraction thermal equipment in the waste heat collection system through the condensate pump.

[0081] The return water from the primary heat network enters the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump and the peak-shaving steam-water heat exchanger in sequence and is heated and heated step by step.

[0082] In order to obtain the low-temperature 16℃ / 23℃ cooling water required by the process, the first double-effect lithium bromide absorption heat pump needs to be turned on all year round. When the heat load changes from small to large, the second water-water heat exchanger in the thermal power station is put into operation at full load during the entire heating period; the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the large-capacity heat storage module and the peak-shaving steam-water heat exchanger in the heat source station can be put into operation step by step according to the increase in heat load; for example, when the load rate exceeds 25%, the second double-effect lithium bromide absorption heat pump is put into operation; when the load rate exceeds 50%, the first single-effect lithium bromide absorption heat pump is put into operation; when the load rate exceeds 75%, the first single-effect lithium bromide absorption heat pump is put into operation. At this time, the large-capacity thermal storage module and peak-shaving steam-water heat exchanger are put into operation, and the load of each level of thermal equipment is increased from a small load to full load. Each level of thermal equipment can only be put into operation after it is fully loaded. As the heat load demand increases further, if the full load of the heat source station's first water-water heat exchanger, second double-effect lithium bromide absorption heat pump, first single-effect lithium bromide absorption heat pump, and large-capacity thermal storage module is still insufficient, the thermal station will then sequentially put into operation the first electric vapor compression heat pump and the second vapor compression heat pump with ejector. The second vapor compression heat pump with ejector can only be put into operation after the first electric vapor compression heat pump is fully loaded. When the heat load decreases from large to small, the above equipment operates in reverse according to the above method. This cascaded heat extraction method, with three levels of energy recovery (high, medium, and low), allows for the deep utilization of waste heat and significantly increases power generation.

[0083] In operation mode 2 of embodiment 1, electric heating is used first when the heat load increases from small to large; the design temperature of the primary supply / return water is 80°C / 20°C, and the design temperature of the secondary supply / return water is 50°C / 40°C.

[0084] High-pressure steam utilization: High-pressure steam from the second heat pipe evaporator and the high-pressure waste heat boiler (HPHB) first enters the high-pressure cylinder of the steam turbine, where it expands and generates work, becoming 1.0 MPa medium-pressure steam. This medium-pressure steam is then split into two paths. The first path enters the process steam pipeline; the second path enters the intermediate-pressure cylinder of the steam turbine, where it continues to expand and generate work, becoming 0.3 MPa medium-low-pressure steam. The medium-low-pressure steam is then split into two paths. The first path combines with the medium-low-pressure steam from the HPHB and the first heat pipe evaporator. The second path enters the low-pressure cylinder of the steam turbine, where it continues to expand and generate work, becoming exhaust steam. This exhaust steam then enters the condenser, where it releases heat and cools down, becoming condensate. The mechanical energy output by the steam turbine drives the generator to generate electricity. This electricity is first supplied to the coking process through the power transmission and distribution system, and is then connected to the municipal grid when sufficient power is available.

[0085] Medium- and low-pressure steam utilization: The medium- and low-pressure steam from the medium- and low-pressure waste heat boilers and the first heat pipe evaporator is mixed with the medium- and low-pressure steam from the steam turbine and then divided into three paths. The first path serves as the working fluid, driving the medium- and low-pressure ejectors to eject steam from the low-pressure ejectors, generating 0.15 MPa low-pressure steam. The second path serves as the driving heat source, driving the first double-effect lithium bromide absorption heat pump to recover waste heat from the low-temperature cooling water and heat the cooling water to 40°C. The third path serves as the driving heat source, driving the second double-effect lithium bromide absorption heat pump to recover waste heat from the low-temperature cooling water and heat the circulating water in the primary heat network. During the heating period, low-temperature heat is preferentially utilized, specifically by using medium- and low-pressure steam to drive the lithium bromide absorption heat pump to recover low-temperature waste heat. This medium- and low-temperature steam is primarily sourced from the medium- and low-pressure boilers, with the medium- and low-temperature steam from the steam turbine serving as a supplementary start-up regulator.

[0086] Low-pressure steam utilization method: The mixed fluid from the medium and low-pressure ejectors is divided into three paths. The first path is used as the working fluid to drive the low-pressure ejector to eject ultra-low-pressure steam from the steam generator; the second path is used as the driving heat source to drive the first single-effect lithium bromide absorption heat pump to recover medium and low-temperature waste heat and heat the primary heat network circulating water; the third path is used as the heating heat source to enter the peak-shaving steam-water heat exchanger to further heat the primary heat network circulating water.

[0087] Method for utilizing medium and high temperature hot water: The medium and high temperature hot water of 85-90°C from the first gas-water heat exchanger and the second gas-water heat exchanger enters the steam generator to generate ultra-low pressure steam, which then enters the low-pressure ejector as the injection fluid.

[0088] Low-temperature cooling water utilization method: The low-temperature cooling water for the process enters the first double-effect lithium bromide absorption heat pump, and the temperature is reduced from 23°C to 16°C.

[0089] Utilization method of high-temperature cooling water: After the 40°C cooling water from the first double-effect lithium bromide absorption heat pump is merged with the 40°C high-temperature cooling water for the process and the 40°C cooling water from the condenser, it is divided into four routes: the first route can enter the closed cooling tower to be cooled to 30°C when there is sufficient low-temperature waste heat; the second, third and fourth routes can enter the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump and the first single-effect lithium bromide absorption heat pump respectively to be recycled.

[0090] Condensate utilization method: The condensate from the peak-shaving steam-water heat exchanger, the first single-effect lithium bromide absorption heat pump, the second double-effect lithium bromide absorption heat pump and the first double-effect lithium bromide absorption heat pump is collected and enters the condensate tank, and then supplied to the heat extraction thermal equipment in the waste heat extraction system through the condensate pump.

[0091] The return water from the primary heating network enters the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump and the peak-shaving steam-water heat exchanger, and is heated step by step to 80°C, and then distributed to various thermal power stations through the primary pipeline network.

[0092] In order to obtain the low-temperature 16℃ / 23℃ cooling water required for the process, the first double-effect lithium bromide absorption heat pump needs to be turned on all year round. When the heat load changes from small to large, the first water-water heat exchanger and the second double-effect lithium bromide absorption heat pump of the heat source station are fully loaded during the entire heating period. The second water-water heat exchanger, the first vapor compression heat pump and the second vapor compression heat pump with ejector of the thermal power station are put into operation in turn; the load of the electric vapor compression heat pump is operated from small to large, and the next level of thermal equipment can only be put into operation after each level of thermal equipment is fully loaded. If the above equipment still cannot meet the heat load demand after full operation, the heat source station sequentially operates the first single-effect lithium bromide absorption heat pump, the large-capacity thermal storage module, and the peak-shaving steam-water heat exchanger. For example, when the load factor exceeds 50%, the first single-effect lithium bromide absorption heat pump is put into operation. When the load factor exceeds 75%, the large-capacity thermal storage module and the peak-shaving steam-water heat exchanger are put into operation in sequence, with the loads increasing from small to large. Each stage of thermal equipment must be fully loaded before the next stage of thermal equipment can be put into operation based on load demand. When the heat load decreases from high to low, the above equipment operates in the reverse order. This cascaded heat extraction method, with high, medium, and low-grade energy recovery, allows for the intensive utilization of waste heat and significantly increases power generation. When the primary water supply's heating capacity exceeds the heat load, the large-capacity thermal storage module is used to store heat. When the primary water supply's heating capacity falls below the heat load, the large-capacity thermal storage module releases heat.

[0093] The coking waste heat cogeneration system coupled with multiple heterogeneous energy flows adopts operation mode 1 or operation mode 2 according to the actual local heat and electricity prices to maximize economic benefits.

[0094] like Figure 3 and Figure 4 In the second embodiment shown, a low-pressure steam-water heat exchanger is added to the multi-heterogeneous energy flow reconstruction and comprehensive utilization system, so that the medium and low pressure steam are more fully utilized and a higher temperature primary hot water is provided. The structure of the waste heat collection system and the waste heat depth collection method are the same as those in the first embodiment.

[0095] The multi-heterogeneous energy flow reconstruction and comprehensive utilization system includes: a low-pressure steam-water heat exchanger, a condenser, a closed cooling tower, a first double-effect lithium bromide absorption heat pump, a second double-effect lithium bromide absorption heat pump, a medium- and low-pressure ejector, a low-pressure ejector, a steam generator, a first water-water heat exchanger, a first single-effect lithium bromide absorption heat pump, a peak-shaving steam-water heat exchanger and a large-capacity heat storage module, wherein the high-pressure steam outlet of the second heat pipe evaporator and the high-pressure waste heat boiler is connected to the main steam inlet of the steam turbine; the steam pipelines of the high-pressure cylinder, medium-pressure cylinder and low-pressure cylinder of the steam turbine are connected in sequence, wherein the steam outlet of the high-pressure cylinder of the steam turbine is branched off and connected to the external medium-pressure steam pipeline for process; the steam outlet of the medium-pressure cylinder of the steam turbine is branched off and connected to the medium- and low-pressure steam of the medium-pressure waste heat boiler and the first heat pipe evaporator After the outlets are merged, (0.3MPa) are respectively connected to the working fluid steam inlet of the medium and low pressure ejectors, the medium and low pressure steam inlet of the peak shaving steam-water heat exchanger, the medium and low pressure steam inlet of the generator in the first double-effect lithium bromide absorption heat pump and the medium and low pressure steam inlet of the generator in the second double-effect lithium bromide absorption heat pump; the mixed fluid outlet of the low pressure ejector is connected to the induced fluid inlet of the medium and low pressure ejector, and the mixed fluid outlet of the medium and low pressure ejector is respectively connected to the working fluid inlet of the low pressure ejector, the low pressure steam inlet of the generator of the first single effect lithium bromide absorption heat pump and the low pressure steam inlet of the low pressure steam-water heat exchanger; the ultra-low pressure steam outlet of the steam generator is connected to the induced fluid inlet of the low pressure ejector; the main shaft of the steam turbine drives the generator to be connected to the power transmission and distribution system;

[0096] The medium- and high-temperature hot water outlets (85-90°C) of the first and second air-water heat exchangers are connected to the hot water inlet of the steam generator; the process low-temperature cooling water outlet (23°C) is connected to the evaporator low-temperature water inlet of the first double-effect lithium bromide absorption heat pump; and the evaporator low-temperature water outlet of the first double-effect lithium bromide absorption heat pump is connected to the process low-temperature cooling water inlet (16°C);

[0097] The high-temperature cooling water outlet (40°C) for the process is merged with the cooling water outlet of the first double-effect lithium bromide absorption heat pump and the cooling water outlet of the condenser, and then connected to the cooling water inlet of the closed cooling tower, the hot side circulating water inlet of the first water-water heat exchanger, the evaporator hot water inlet of the second double-effect lithium bromide absorption heat pump, and the evaporator hot water inlet of the first single-effect lithium bromide absorption heat pump respectively;

[0098] The evaporator hot water outlet of the first single-effect lithium bromide absorption heat pump, the cooling water outlet of the closed cooling tower, the hot side circulating water outlet of the first water-water heat exchanger, and the evaporator hot water outlet of the second double-effect lithium bromide absorption heat pump are respectively connected to the cooling water inlet of the condenser, the cooling water inlet of the first double-effect lithium bromide absorption heat pump, and the high-temperature cooling water inlet for the process; the steam condensate outlet of the peak-shaving steam-water heat exchanger, the steam condensate outlet of the low-pressure steam-water heat exchanger, the steam condensate outlet of the generator of the first single-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the second double-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the first double-effect lithium bromide absorption heat pump, the steam condensate outlet of the steam generator, and the steam condensate outlet of the condenser are connected to the condensate inlet of the condensate tank after merging;

[0099] The condensate outlet of the condensate tank is connected to the condensate side inlet of the first air-water heat exchanger, the water side inlet of the second air-water heat exchanger, the condensate inlet of the first heat pipe evaporator, the condensate inlet of the medium-pressure waste heat boiler, the condensate inlet of the high-pressure waste heat boiler, and the condensate inlet of the second heat pipe evaporator in the waste heat collection system through a condensate pump;

[0100] The return water pipeline of the primary heat network is connected to the low-temperature side circulating water inlet of the first water-water heat exchanger and the low-temperature water pipeline of the large-capacity heat storage module; the low-temperature side circulating water outlet of the first water-water heat exchanger is connected to the primary water inlet of the absorber of the second double-effect lithium bromide absorption heat pump; the condenser primary water outlet of the second double-effect lithium bromide absorption heat pump is connected to the absorber primary water inlet of the first single-effect lithium bromide absorption heat pump; the condenser primary water outlet of the first single-effect lithium bromide absorption heat pump is connected to the primary water inlet of the low-pressure steam-water heat exchanger; the primary water outlet of the low-pressure steam-water heat exchanger is connected to the primary water inlet of the peak-shaving steam-water heat exchanger; the primary water outlet of the peak-shaving steam-water heat exchanger is connected to the primary heat network water supply pipeline and the high-temperature water pipeline of the large-capacity heat storage module.

[0101] like Figure 4 The thermal power station of the second embodiment shown includes: a single-effect lithium bromide absorption heat pump of the thermal power station, a semi-effect lithium bromide absorption heat pump and a third water-water heat exchanger; wherein, the single-effect lithium bromide absorption heat pump of the thermal power station mainly includes: a generator, a third condenser, a solution heat exchanger, an absorber and a third evaporator; the semi-effect lithium bromide absorption heat pump mainly includes: a high-pressure generator, a low-pressure generator, a fourth condenser, a high-temperature solution heat exchanger, a low-temperature solution heat exchanger, a high-pressure absorber, a low-pressure absorber and a fourth evaporator.

[0102] In the heating station, the primary heating network water supply pipeline is connected to the inlet of the primary water side of the generator of the single-effect lithium bromide absorption heat pump of the heating station; the outlet of the primary water side of the generator of the single-effect lithium bromide absorption heat pump of the heating station is connected to the inlet of the primary water side of the high-pressure generator of the semi-effect lithium bromide absorption heat pump; the outlet of the primary water side of the high-pressure generator of the semi-effect lithium bromide absorption heat pump is connected to the inlet of the primary water side of the low-pressure generator of the semi-effect lithium bromide absorption heat pump; the outlet of the primary water side of the low-pressure generator of the semi-effect lithium bromide absorption heat pump is connected to the inlet of the primary water side of the low-pressure generator of the semi-effect lithium bromide absorption heat pump. The outlet of the secondary water side is connected to the inlet of the primary water side of the third water-water heat exchanger; the outlet of the primary water side of the third water-water heat exchanger is connected to the inlet of the primary water side of the third evaporator of the single-effect lithium bromide absorption heat pump of the thermal power station; the outlet of the primary water side of the third evaporator of the single-effect lithium bromide absorption heat pump of the thermal power station is connected to the inlet of the primary water side of the fourth evaporator of the semi-effect lithium bromide absorption heat pump; the outlet of the primary water side of the fourth evaporator of the semi-effect lithium bromide absorption heat pump is connected to the return water pipe of the primary heating network.

[0103] The secondary heat network return water pipeline (40℃) is divided into three routes, which are respectively connected to the inlet of the secondary water side of the third water-water heat exchanger, the inlet of the secondary water side of the first absorber in the single-effect lithium bromide absorption heat pump of the thermal power station, and the inlet of the secondary water side of the low-pressure absorber in the semi-effect lithium bromide absorption heat pump; the outlet of the secondary water side of the third water-water heat exchanger is connected to the secondary heat network water supply pipeline, the outlet of the secondary water side of the first absorber is connected to the secondary heat network water supply pipeline after absorbing heat through the secondary water side of the third condenser, and the outlet of the secondary water side of the low-pressure absorber is connected to the secondary heat network water supply pipeline after absorbing heat through the secondary water side of the high-pressure absorber and the secondary water side of the fourth condenser. The 130°C primary heating network water is gradually released and cooled to 10°C in the generator of the single-effect lithium bromide absorption heat pump of the thermal power station, the high-pressure generator of the semi-effect lithium bromide absorption heat pump, the low-pressure generator of the semi-effect lithium bromide absorption heat pump, the third water-water heat exchanger, the third evaporator of the single-effect lithium bromide absorption heat pump of the thermal power station, and the fourth evaporator of the semi-effect lithium bromide absorption heat pump.

[0104] The operation method of the second embodiment is as follows: the design temperature of the primary supply / return water is 130°C / 10°C, and the design temperature of the secondary supply / return water is 50°C / 40°C.

[0105] High-pressure steam utilization: 5.1-5.3 MPa high-pressure steam from the second heat pipe evaporator and high-pressure waste heat boiler enters the high-pressure cylinder of the steam turbine, where it expands and generates work, becoming 1.0 MPa medium-pressure steam. The medium-pressure steam is split into two paths: one path enters the process medium-pressure steam pipeline, while the other path enters the medium-pressure cylinder of the steam turbine, where it continues to expand and generate work, becoming 0.3 MPa medium-low-pressure steam. The medium-low-pressure steam is split into two paths: one path enters the low-pressure cylinder of the steam turbine, where it continues to expand and generate work, becoming exhaust steam and entering the condenser, where it is cooled and converted into condensate. The other path serves as heat extraction steam and is mixed with the medium-low-pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator.

[0106] Medium- and low-pressure steam utilization method: 0.3MPa medium- and low-pressure steam is divided into four paths. The first path serves as the working fluid and enters the medium- and low-pressure ejector to eject steam from the low-pressure ejector, converting it into 0.15MPa low-pressure steam. The second path serves as the driving heat source to drive the first double-effect lithium bromide absorption heat pump to recover waste heat from the process's low-temperature cooling water. The third path serves as the driving heat source to drive the second double-effect lithium bromide absorption heat pump to recover low-temperature waste heat and heat the primary heat network circulating water. The fourth path serves as the heating heat source and enters the peak-shaving medium- and low-pressure steam-water heat exchanger to heat the primary heat network circulating water. During the heating period, low-temperature heat is preferentially utilized, specifically by using medium- and low-pressure steam to drive the lithium bromide absorption heat pump to recover low-temperature waste heat. This medium- and low-temperature steam is primarily sourced from medium- and low-pressure boilers, and the medium- and low-temperature steam from the steam turbine serves as a supplementary regulator for startup.

[0107] Low-pressure steam utilization method: The 0.15MPa low-pressure steam from the medium and low-pressure ejectors is divided into three paths. The first path enters the low-pressure ejector as a working fluid to inject ultra-low-pressure steam from the steam generator; the second path enters the first single-effect lithium bromide absorption heat pump as a driving heat source to recover low-temperature waste heat and heat the primary heat network circulating water; the third path enters the low-pressure steam-water heat exchanger as a heating heat source to heat the primary heat network circulating water.

[0108] Medium- and high-temperature hot water utilization: 85-90°C medium- and high-temperature hot water from the first and second air-water heat exchangers enters the steam generator, generating ultra-low-pressure steam, which serves as the injection fluid for the low-pressure ejector. Driven by the medium- and low-pressure steam, the medium- and low-pressure ejector ejects the mixed fluid from the low-pressure ejector, producing 0.15MPa low-pressure steam.

[0109] Low-temperature cooling water utilization method: The low-temperature cooling water for the process enters the first double-effect lithium bromide absorption heat pump, and the temperature is reduced from 23°C to 16°C.

[0110] High-temperature cooling water utilization method: After the circulating cooling water from the first double-effect lithium bromide absorption heat pump and the circulating cooling water from the condenser are merged with the high-temperature cooling water for the process, they enter the first water-water heat exchanger, the evaporator of the second double-effect lithium bromide absorption heat pump, the evaporator of the first single-effect lithium bromide absorption heat pump and the closed cooling tower in parallel for heat release and cooling.

[0111] Condensate utilization method: the condensate from the peak-shaving medium and low-pressure steam-water heat exchangers, the low-pressure steam-water heat exchanger, the first single-effect lithium bromide absorption heat pump, the second double-effect lithium bromide absorption heat pump, the condenser and the first double-effect lithium bromide absorption heat pump is merged and enters the condensate tank; the condensate from the condensate tank enters the first gas-water heat exchanger, the first heat pipe evaporator, the second gas-water heat exchanger, the medium-pressure waste heat boiler, the high-pressure waste heat boiler and the second heat pipe evaporator in the waste heat collection system in parallel under the action of the condensate pump.

[0112] The return water from the primary heating network enters the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the low-pressure steam-water heat exchanger, and the peak-shaving medium- and low-pressure steam-water heat exchanger, where it is heated step by step. When the heating capacity of the multi-heterogeneous energy flow reconstruction and comprehensive utilization system exceeds the heat load demand, the large-capacity thermal storage module stores heat; when the heating capacity of the multi-heterogeneous energy flow reconstruction and comprehensive utilization system is less than the heat load demand, the large-capacity thermal storage module releases heat.

[0113] The primary heat network water first serves as a driving heat source, entering the single-effect lithium bromide absorption heat pump and the semi-effect lithium bromide absorption heat pump in the thermal power station in sequence. It then serves as a heating heat source and enters the third water-to-water heat exchanger. Finally, it serves as a low-temperature heat source and enters the third evaporator of the second single-effect lithium bromide absorption heat pump and the fourth evaporator of the semi-effect lithium bromide absorption heat pump in sequence, thereby gradually releasing heat and cooling the primary heat network circulating water to 10°C. The return water from the secondary heat network is divided into three parallel routes and enters the third water-to-water heat exchanger, the second single-effect lithium bromide absorption heat pump, and the semi-effect lithium bromide absorption heat pump, respectively, where it is heated and then merged. It then serves as secondary water supply and enters the secondary heat network water supply pipeline.

[0114] To obtain the low-temperature 16°C / 23°C cooling water required for the process, the first double-effect lithium bromide absorption heat pump must be operated year-round. As the heat load increases, the heat source station's first water-to-water heat exchanger, second double-effect lithium bromide absorption heat pump, first single-effect lithium bromide absorption heat pump, large-capacity thermal storage module, and low-pressure steam-to-water heat exchanger are sequentially put into operation. The load of each thermal equipment stage is increased from low to full load before the next stage can be put into operation. For example, when the load rate exceeds 21%, the second double-effect lithium bromide absorption heat pump is put into operation; when the load rate exceeds 33%, the first single-effect lithium bromide absorption heat pump is put into operation; and when the load rate exceeds 50%, the low-pressure steam-to-water heat exchanger is put into operation. If all the aforementioned thermal equipment at the heat source station is operational and still cannot meet the heat load demand, the large-capacity thermal storage module will be put into operation. If the heat load increases further and the load factor reaches 79%, the peak-shaving medium- and low-pressure steam-water heat exchanger will be finally activated. When the heating capacity of the primary water supply exceeds the heat load, the large-capacity thermal storage module will also be used to store heat; when the heating capacity of the primary water supply is lower than the heat load, the large-capacity thermal storage module will release heat.

[0115] To maximize the collection and efficient utilization of waste heat from the coking process, the above embodiments employ a step-by-step heat extraction method to collect waste heat. This results in energy recovery and utilization at three levels: high, medium, and low. The grades and quantities of multiple heterogeneous heat flows are optimized and reconstructed to achieve cascaded, efficient, and intensive utilization of the energy of complex, multi-grade heat flows. This transforms disordered heat flows into an orderly fashion, reducing irreversible losses in the waste heat utilization process. This improves waste heat utilization efficiency and significantly increases power generation. Furthermore, it meets the low-loss exergy heating requirements of the primary heat network's circulating water cascade, enhances the coking process's power and heat self-sufficiency, and reduces carbon emissions per unit of production capacity.

Claims

1. A coking waste heat cogeneration system with multiple heterogeneous energy flow coupling, characterized in that: include: Waste heat collection system, multi-heterogeneous energy flow reconstruction and comprehensive utilization system, primary heating network, thermal power station, secondary heating network; The waste heat collection system includes: a second heat pipe evaporator for recovering sensible waste heat of raw coal gas, a second gas-water heat exchanger for recovering waste heat of red coke, a high-pressure waste heat boiler and a medium-pressure waste heat boiler, and a first gas-water heat exchanger and a first heat pipe evaporator for recovering waste heat of flue gas; The multi-heterogeneous energy flow reconstruction and comprehensive utilization system includes: a condenser, a closed cooling tower, a first double-effect lithium bromide absorption heat pump, a second double-effect lithium bromide absorption heat pump, medium and low pressure ejectors, a low pressure ejector, a steam generator, a first water-water heat exchanger, a first single-effect lithium bromide absorption heat pump, a peak-shaving steam-water heat exchanger and a large-capacity heat storage module, wherein the high-pressure steam outlet of the second heat pipe evaporator and the high-pressure waste heat boiler is connected to the main steam inlet of the steam turbine; the steam pipelines of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder of the steam turbine are connected in sequence, wherein the steam outlet of the high-pressure cylinder of the steam turbine is branched off and connected to the external medium-pressure steam pipeline for process; the steam outlet of the medium-pressure cylinder of the steam turbine is branched off and connected to the medium-pressure waste heat boiler and the first heat pipe evaporator. After the medium and low pressure steam outlets of the tube evaporator are merged, they are respectively connected to the working fluid steam inlet of the medium and low pressure ejector, the medium and low pressure steam inlet of the generator in the first double-effect lithium bromide absorption heat pump, and the medium and low pressure steam inlet of the generator in the second double-effect lithium bromide absorption heat pump; the mixed fluid outlet of the low pressure ejector is connected to the ejection fluid inlet of the medium and low pressure ejector, and the low pressure steam of 0.15 MPa at the mixed fluid outlet of the medium and low pressure ejector is respectively connected to the working fluid inlet of the low pressure ejector, the low pressure steam inlet of the generator of the first single-effect lithium bromide absorption heat pump, and the low pressure steam inlet of the peak shaving steam-water heat exchanger; the ultra-low pressure steam outlet of the steam generator is connected to the ejection fluid inlet of the low pressure ejector; The medium- and high-temperature hot water side outlets of the first air-water heat exchanger and the second air-water heat exchanger are connected to the hot water inlet of the steam generator; the process low-temperature cooling water outlet is connected to the low-temperature water inlet of the evaporator of the first double-effect lithium bromide absorption heat pump; the evaporator low-temperature water outlet of the first double-effect lithium bromide absorption heat pump is connected to the process low-temperature cooling water inlet; the process high-temperature cooling water outlet is connected to the cooling water outlet of the first double-effect lithium bromide absorption heat pump and the cooling water outlet of the condenser after merging with the cooling water inlet of the closed cooling tower, the hot side circulating water inlet of the first water-water heat exchanger, the evaporator hot water inlet of the second double-effect lithium bromide absorption heat pump, and the evaporator hot water inlet of the first single-effect lithium bromide absorption heat pump; The hot water outlet of the evaporator of the first single-effect lithium bromide absorption heat pump, the cooling water outlet of the closed cooling tower, the hot side circulating water outlet of the first water-water heat exchanger and the hot water outlet of the evaporator of the second double-effect lithium bromide absorption heat pump are respectively connected to the cooling water inlet of the condenser, the cooling water inlet of the first double-effect lithium bromide absorption heat pump and the high-temperature cooling water inlet for the process; the primary heat network return water pipeline is connected to the low-temperature side circulating water inlet of the first water-water heat exchanger and the low-temperature water pipeline of the large-capacity thermal storage module; the first The low-temperature side circulating water outlet of the water-water heat exchanger is connected to the primary water inlet of the absorber of the second double-effect lithium bromide absorption heat pump; the primary water outlet of the condenser of the second double-effect lithium bromide absorption heat pump is connected to the primary water inlet of the absorber of the first single-effect lithium bromide absorption heat pump; the primary water outlet of the condenser of the first single-effect lithium bromide absorption heat pump is connected to the primary water inlet of the peak-shaving steam-water heat exchanger; the primary water outlet of the peak-shaving steam-water heat exchanger is connected to the primary heating network water supply pipeline and the high-temperature water pipeline of the large-capacity thermal storage module; The thermal power station includes: a second water-water heat exchanger, a first electric vapor compression heat pump and a second electric vapor compression heat pump with an ejector; wherein the first electric vapor compression heat pump includes: a first condenser, a first throttling device, a first compressor, and a high-pressure evaporator; the first compressor, the working fluid side of the first condenser, the first throttling device, the working fluid side of the high-pressure evaporator and the first compressor are connected in sequence to form a loop; the second electric vapor compression heat pump includes: a second condenser, a gas-gas ejector, a low-pressure evaporator, a second throttling device, a gas-liquid separator and a second compressor; the second compressor, the working fluid side of the second condenser, the working fluid inlet of the ejector, the mixed fluid outlet of the ejector and the working fluid inlet of the gas-liquid separator, the gaseous working fluid outlet of the gas-liquid separator and the second compressor are connected in sequence to form a loop; the liquid working fluid outlet of the gas-liquid separator is connected to the ejector fluid inlet via the second throttling device and the working fluid side of the low-pressure evaporator in sequence.

2. The coking waste heat cogeneration system with multiple heterogeneous energy flow coupling according to claim 1 is characterized in that: The steam condensate outlet of the peak-shaving steam-water heat exchanger, the steam condensate outlet of the generator of the first single-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the second double-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the first double-effect lithium bromide absorption heat pump, the steam condensate outlet of the steam generator and the steam condensate outlet of the condenser are connected to the condensate inlet of the condensate tank after merging; The condensate outlet of the condensate tank is respectively connected to the condensate side inlet of the first gas-water heat exchanger, the condensate inlet of the first heat pipe evaporator, the water side inlet of the second gas-water heat exchanger, the condensate inlet of the medium-pressure waste heat boiler, the condensate inlet of the high-pressure waste heat boiler and the condensate inlet of the second heat pipe evaporator in the waste heat collection system through a condensate pump.

3. The coking waste heat cogeneration system with multiple heterogeneous energy flow coupling according to claim 1 is characterized in that: The second heat pipe evaporator recovers the sensible heat of the raw gas in the temperature range of 450-800°C to produce 5.1-5.3MPa high-pressure steam; The high-pressure waste heat boiler recovers the heat of the high-temperature inert gas N2 to produce 5.1-5.3 MPa high-pressure steam; the medium-pressure waste heat boiler recovers the heat of the medium-temperature inert gas N2 to produce 0.3 MPa medium-low-pressure steam; the second gas-water heat exchanger is used to recover the heat of the medium-low temperature inert gas N2 to produce medium-high-temperature hot water of 85-90°C; the high-temperature inert gas N2, the medium-temperature inert gas N2 and the medium-low temperature inert gas N2 are all recovered from the coke quenching drum; The first heat pipe evaporator recovers waste heat from flue gas in the medium temperature range to produce 0.3MPa steam; the first gas-water heat exchanger recovers waste heat from flue gas in the medium and low temperature range to produce medium and high temperature hot water of 85-90°C.

4. An operating method of the coking waste heat cogeneration system based on the multi-heterogeneous energy flow coupling according to claim 1, characterized in that: High-pressure steam from the second heat pipe evaporator and high-pressure waste heat boiler enters the high-pressure cylinder of the steam turbine, expands and produces work, and becomes 1.0 MPa medium-pressure steam. A portion of the medium-pressure steam from the high-pressure cylinder of the steam turbine enters the medium-pressure steam pipeline for the process, and another portion of the medium-pressure steam enters the intermediate-pressure cylinder of the steam turbine to continue expanding and produce work, becoming 0.3 MPa medium-low-pressure steam. A portion of the medium-low-pressure steam from the intermediate-pressure cylinder of the steam turbine is mixed with the medium-low-pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator, and another portion of the medium-low-pressure steam enters the low-pressure cylinder of the steam turbine to continue expanding and produce work, becoming exhaust steam and entering the condenser, where it is cooled and converted into condensate. The mechanical energy output by the steam turbine drives the generator to generate electricity. The generated electricity is first supplied to the coking process through the power transmission and distribution system, and can only be connected to the municipal power grid when there is sufficient electricity. The medium- and low-pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator is first mixed with part of the medium- and low-pressure steam from the medium-pressure cylinder of the steam turbine, and then divided into three paths: the first path is used as a working fluid to drive the medium- and low-pressure ejectors to inject the steam from the low-pressure ejectors and become 0.15MPa low-pressure steam at the outlet of the medium- and low-pressure ejector mixing chamber; The second path is used as a driving heat source to drive the first double-effect lithium bromide absorption heat pump to recover the low-temperature cooling waste heat from the coking plant; The third path is used as a driving heat source to drive the second double-effect lithium bromide absorption heat pump to recycle and utilize medium and low temperature waste heat; The mixed fluid from the medium and low pressure ejectors is divided into three paths. The first path is used as the working fluid to drive the low pressure ejector to eject ultra-low pressure steam from the steam generator; the second path is used as the driving heat source to drive the first single-effect lithium bromide absorption heat pump to recover medium and low temperature waste heat and heat the primary heat network circulating water; the third path is used as the heating heat source to enter the peak-shaving steam-water heat exchanger to further heat the primary heat network circulating water. The medium-high temperature hot water of 85-90℃ from the first and second gas-water heat exchangers first enters the steam generator to generate ultra-low pressure steam, which then enters the low-pressure ejector as the ejector fluid. The low-temperature cooling water for the process enters the first double-effect lithium bromide absorption heat pump, where its water temperature is reduced from 23°C to 16°C, and at the same time the cooling water is heated from 30°C to 40°C; The 40°C cooling water from the first double-effect lithium bromide absorption heat pump is combined with the 40°C cooling water for the process and the 40°C cooling water from the condenser, and then divided into four routes. The first route can enter the closed cooling tower when sufficient waste heat is available and be cooled to 30°C. The second, third, and fourth routes enter the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, and the first single-effect lithium bromide absorption heat pump, respectively, and are recycled and used to heat the circulating water of the primary heat network. The condensate from the peak-shaving steam-water heat exchanger, the first single-effect lithium bromide absorption heat pump, the second double-effect lithium bromide absorption heat pump, the first water-water heat exchanger and the first double-effect lithium bromide absorption heat pump is first collected and enters the condensate tank, and then supplied to the heat extraction thermal equipment in the waste heat collection system through the condensate pump; the return water from the primary heat network enters the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump and the peak-shaving steam-water heat exchanger in turn and is heated and heated step by step.

5. The method for coking waste heat cogeneration with multi-heterogeneous energy flow coupling according to claim 4, characterized in that: The first double-effect lithium bromide absorption heat pump is continuously turned on; When the heat load increases from small to large, the second water-water heat exchanger in the thermal power station is put into operation at full load during the entire heating period; the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the large-capacity heat storage module and the peak-shaving steam-water heat exchanger in the heat source station can be put into operation step by step according to the increase in heat load; if the heat load demand increases further, the thermal power station will then put into operation the first electric vapor compression heat pump and the second vapor compression heat pump with ejector in sequence.

6. The method for coking waste heat cogeneration with multi-heterogeneous energy flow coupling according to claim 4, characterized in that: The first double-effect lithium bromide absorption heat pump is continuously turned on; When the heat load changes from small to large, the first water-water heat exchanger and the second double-effect lithium bromide absorption heat pump of the heat source station will operate at full load during the entire heating period, and the second water-water heat exchanger, the first vapor compression heat pump and the second vapor compression heat pump with ejector of the thermal power station will be put into operation in sequence; the load of the electric vapor compression heat pump will all be operated from small to large; if the heat load demand continues to increase, the heat source station will first put into operation the first single-effect lithium bromide absorption heat pump, and then put into operation the large-capacity heat storage module and the peak-shaving steam-water heat exchanger.

7. A coking waste heat cogeneration system with multiple heterogeneous energy flow coupling, characterized in that: include: Waste heat collection system, multi-heterogeneous energy flow reconstruction and comprehensive utilization system, primary heating network, thermal power station, secondary heating network; The waste heat collection system includes: a second heat pipe evaporator for recovering sensible waste heat of raw coal gas, a second gas-water heat exchanger for recovering waste heat of red coke, a high-pressure waste heat boiler and a medium-pressure waste heat boiler, and a first gas-water heat exchanger and a first heat pipe evaporator for recovering waste heat of flue gas; The multi-heterogeneous energy flow reconstruction and comprehensive utilization system includes: a low-pressure steam-water heat exchanger, a condenser, a closed cooling tower, a first double-effect lithium bromide absorption heat pump, a second double-effect lithium bromide absorption heat pump, a medium- and low-pressure ejector, a low-pressure ejector, a steam generator, a first water-water heat exchanger, a first single-effect lithium bromide absorption heat pump, a peak-shaving steam-water heat exchanger and a large-capacity heat storage module, wherein the high-pressure steam outlet of the second heat pipe evaporator and the high-pressure waste heat boiler is connected to the main steam inlet of the steam turbine; the steam pipelines of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder of the steam turbine are connected in sequence, wherein the steam outlet of the high-pressure cylinder of the steam turbine branches off and is connected to an external medium-pressure steam pipeline for process; the steam outlet of the medium-pressure cylinder of the steam turbine branches off and is connected to the medium-pressure waste heat boiler and the first heat pipe evaporator. After the medium and low pressure steam outlets of 0.3MPa are merged, they are respectively connected to the working fluid steam inlet of the medium and low pressure ejector, the medium and low pressure steam inlet of the peak shaving steam-water heat exchanger, the medium and low pressure steam inlet of the generator in the first double-effect lithium bromide absorption heat pump and the medium and low pressure steam inlet of the generator in the second double-effect lithium bromide absorption heat pump; the mixed fluid outlet of the low pressure ejector is connected to the ejection fluid inlet of the medium and low pressure ejector, and the low pressure steam of 0.15MPa at the mixed fluid outlet of the medium and low pressure ejector is respectively connected to the working fluid inlet of the low pressure ejector, the low pressure steam inlet of the generator of the first single effect lithium bromide absorption heat pump and the low pressure steam inlet of the low pressure steam-water heat exchanger; the ultra-low pressure steam outlet of the steam generator is connected to the ejection fluid inlet of the low pressure ejector; The medium and high temperature hot water outlets of the first air-water heat exchanger and the second air-water heat exchanger are connected to the hot water inlet of the steam generator; the process low temperature cooling water outlet is connected to the low temperature water inlet of the evaporator of the first double-effect lithium bromide absorption heat pump; the low temperature water outlet of the evaporator of the first double-effect lithium bromide absorption heat pump is connected to the process low temperature cooling water inlet; the process high temperature cooling water outlet is connected to the cooling water outlet of the first double-effect lithium bromide absorption heat pump and the cooling water outlet of the condenser after merging with the cooling water inlet of the closed cooling tower, the first water-water exchanger and the cooling water outlet of the condenser. The hot side circulating water inlet of the heat exchanger, the evaporator hot water inlet of the second double-effect lithium bromide absorption heat pump and the evaporator hot water inlet of the first single-effect lithium bromide absorption heat pump are connected; the evaporator hot water outlet of the first single-effect lithium bromide absorption heat pump, the cooling water outlet of the closed cooling tower, the hot side circulating water outlet of the first water-water heat exchanger and the evaporator hot water outlet of the second double-effect lithium bromide absorption heat pump are merged and respectively connected to the cooling water inlet of the condenser, the cooling water inlet of the first double-effect lithium bromide absorption heat pump and the high-temperature cooling water inlet for the process; The primary heat network return water pipeline is connected to the low-temperature side circulating water inlet of the first water-water heat exchanger and the low-temperature water pipeline of the large-capacity heat storage module; the low-temperature side circulating water outlet of the first water-water heat exchanger is connected to the absorber primary water inlet of the second double-effect lithium bromide absorption heat pump; the condenser primary water outlet of the second double-effect lithium bromide absorption heat pump is connected to the absorber primary water inlet of the first single-effect lithium bromide absorption heat pump; the condenser primary water outlet of the first single-effect lithium bromide absorption heat pump is connected to the primary water inlet of the low-pressure steam-water heat exchanger; the primary water outlet of the low-pressure steam-water heat exchanger is connected to the primary water inlet of the peak-shaving steam-water heat exchanger; the primary water outlet of the peak-shaving steam-water heat exchanger is connected to the primary heat network water supply pipeline and the high-temperature water pipeline of the large-capacity heat storage module; The thermal power station includes: a single-effect lithium bromide absorption heat pump of the thermal power station, a semi-effect lithium bromide absorption heat pump and a third water-water heat exchanger; wherein the single-effect lithium bromide absorption heat pump of the thermal power station mainly includes: a generator, a third condenser, a solution heat exchanger, an absorber and a third evaporator; the semi-effect lithium bromide absorption heat pump mainly includes: a high-pressure generator, a low-pressure generator, a fourth condenser, a high-temperature solution heat exchanger, a low-temperature solution heat exchanger, a high-pressure absorber, a low-pressure absorber and a fourth evaporator; wherein, the primary heat network water supply pipeline is connected to the inlet of the primary water side of the generator of the single-effect lithium bromide absorption heat pump of the thermal power station; the outlet of the primary water side of the generator of the single-effect lithium bromide absorption heat pump of the thermal power station is connected to the high-pressure generator of the semi-effect lithium bromide absorption heat pump. The inlet of the secondary water side is connected; the outlet of the primary water side of the high-pressure generator of the semi-effect lithium bromide absorption heat pump is connected to the inlet of the primary water side of the low-pressure generator of the semi-effect lithium bromide absorption heat pump; the outlet of the primary water side of the low-pressure generator of the semi-effect lithium bromide absorption heat pump is connected to the inlet of the primary water side of the third water-water heat exchanger; the outlet of the primary water side of the third water-water heat exchanger is connected to the inlet of the primary water side of the third evaporator of the single-effect lithium bromide absorption heat pump of the thermal power station; the outlet of the primary water side of the third evaporator of the single-effect lithium bromide absorption heat pump of the thermal power station is connected to the inlet of the primary water side of the fourth evaporator of the semi-effect lithium bromide absorption heat pump; the outlet of the primary water side of the fourth evaporator of the semi-effect lithium bromide absorption heat pump is connected to the return water pipe of the primary heating network; The return water pipeline of the secondary heat network is divided into three routes, which are respectively connected to the inlet of the secondary water side of the third water-water heat exchanger, the inlet of the secondary water side of the first absorber in the single-effect lithium bromide absorption heat pump of the thermal power station, and the inlet of the secondary water side of the low-pressure absorber in the semi-effect lithium bromide absorption heat pump; the outlet of the secondary water side of the third water-water heat exchanger is connected to the secondary heat network water supply pipeline, the outlet of the secondary water side of the first absorber is connected to the secondary heat network water supply pipeline after absorbing heat through the secondary water side of the third condenser, and the outlet of the secondary water side of the low-pressure absorber is connected to the secondary heat network water supply pipeline after absorbing heat through the secondary water side of the high-pressure absorber and the secondary water side of the fourth condenser.

8. The coking waste heat cogeneration system with multiple heterogeneous energy flow coupling according to claim 7 is characterized in that: The steam condensate outlet of the peak-shaving steam-water heat exchanger, the steam condensate outlet of the low-pressure steam-water heat exchanger, the steam condensate outlet of the generator of the first single-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the second double-effect lithium bromide absorption heat pump, the steam condensate outlet of the generator of the first double-effect lithium bromide absorption heat pump, the steam condensate outlet of the steam generator and the steam condensate outlet of the condenser are connected to the condensate inlet of the condensate tank after merging; The condensate outlet of the condensate tank is respectively connected to the condensate side inlet of the first air-water heat exchanger, the water side inlet of the second air-water heat exchanger, the condensate inlet of the first heat pipe evaporator, the condensate inlet of the medium-pressure waste heat boiler, the condensate inlet of the high-pressure waste heat boiler and the condensate inlet of the second heat pipe evaporator in the waste heat collection system through a condensate pump.

9. The coking waste heat cogeneration system with multiple heterogeneous energy flow coupling according to claim 7, characterized in that: The second heat pipe evaporator recovers the sensible heat of the raw gas in the temperature range of 450-800°C to produce 5.1-5.3MPa high-pressure steam; The high-pressure waste heat boiler recovers the heat of the high-temperature inert gas N2 to produce 5.1-5.3 MPa high-pressure steam; the medium-pressure waste heat boiler recovers the heat of the medium-temperature inert gas N2 to produce 0.3 MPa medium-low-pressure steam; the second gas-water heat exchanger is used to recover the heat of the medium-low temperature inert gas N2 to produce medium-high-temperature hot water of 85-90°C; the high-temperature inert gas N2, the medium-temperature inert gas N2 and the medium-low temperature inert gas N2 are all recovered from the coke quenching drum; The first heat pipe evaporator recovers waste heat from flue gas in the medium temperature range to produce 0.3MPa steam; the first gas-water heat exchanger recovers waste heat from flue gas in the medium and low temperature range to produce medium and high temperature hot water of 85-90°C.

10. An operating method of the coking waste heat cogeneration system based on the multi-heterogeneous energy flow coupling according to claim 7, characterized in that: The 5.1-5.3 MPa high-pressure steam from the second heat pipe evaporator and the high-pressure waste heat boiler enters the high-pressure cylinder of the steam turbine for expansion and work, and then becomes 1.0 MPa medium-pressure steam; the medium-pressure steam is divided into two paths, one path enters the process medium-pressure steam pipeline, and the other path enters the medium-pressure cylinder of the steam turbine for further expansion and work, and then becomes 0.3 MPa medium-low pressure steam; the medium-low pressure steam is divided into two paths, one path enters the low-pressure cylinder of the steam turbine for further expansion and work, and then becomes exhaust steam and enters the condenser, where it is cooled and converted into condensate; the other path of medium-low pressure steam is used as heat extraction steam and mixed with the medium-low pressure steam from the medium-pressure waste heat boiler and the first heat pipe evaporator; The 0.3MPa medium and low pressure steam is divided into four paths. The first path enters the medium and low pressure ejector as the working fluid to eject the steam from the low pressure ejector and becomes 0.15MPa low pressure steam. The second path is used as a driving heat source to drive the first double-effect lithium bromide absorption heat pump to recover the waste heat of the low-temperature cooling water used in the process; the third path is used as a driving heat source to drive the second double-effect lithium bromide absorption heat pump to recover and utilize the low-temperature waste heat and heat the primary heat network circulating water; the fourth path is used as a heating heat source to enter the peak-shaving medium and low-pressure steam-water heat exchanger to heat the primary heat network circulating water; The 0.15MPa low-pressure steam from the medium and low-pressure ejectors is divided into three paths. The first path enters the low-pressure ejector as the working fluid and ejects the ultra-low-pressure steam from the steam generator. The second path is used as a driving heat source to enter the first single-effect lithium bromide absorption heat pump, recovering low-temperature waste heat and heating the primary heat network circulating water; the third path is used as a heating heat source to enter the low-pressure steam-water heat exchanger to heat the primary heat network circulating water; The medium-high temperature hot water of 85-90℃ from the first gas-water heat exchanger and the second gas-water heat exchanger enters the steam generator to generate ultra-low pressure steam, which is used as the injection fluid of the low-pressure ejector. The medium and low pressure ejectors are driven by medium and low pressure steam to eject the mixed fluid from the low pressure ejectors to produce 0.15 MPa low pressure steam; The low-temperature cooling water for the process enters the first double-effect lithium bromide absorption heat pump, and the temperature is reduced from 23°C to 16°C; The circulating cooling water from the first double-effect lithium bromide absorption heat pump, the circulating cooling water from the condenser and the high-temperature cooling water for the process are combined and then enter the first water-water heat exchanger, the evaporator of the second double-effect lithium bromide absorption heat pump, the evaporator of the first single-effect lithium bromide absorption heat pump and the closed cooling tower in parallel to release heat and cool down; The condensate from the peak-shaving medium- and low-pressure steam-water heat exchangers, the low-pressure steam-water heat exchanger, the first single-effect lithium bromide absorption heat pump, the second double-effect lithium bromide absorption heat pump, the condenser, and the first double-effect lithium bromide absorption heat pump is combined and enters the condensate tank; the condensate from the condensate tank enters the first gas-water heat exchanger, the first heat pipe evaporator, the second gas-water heat exchanger, the medium-pressure waste heat boiler, the high-pressure waste heat boiler, and the second heat pipe evaporator in the waste heat collection system in parallel under the action of the condensate pump; The return water from the primary heating network enters the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the low-pressure steam-water heat exchanger, and the peak-shaving medium- and low-pressure steam-water heat exchanger in sequence, and is heated and heated step by step. When the heating capacity of the multi-heterogeneous energy flow reconstruction and comprehensive utilization system is greater than the heat load demand, the large-capacity heat storage module stores heat; when the heating capacity of the multi-heterogeneous energy flow reconstruction and comprehensive utilization system is less than the heat load demand, the large-capacity heat storage module releases heat. The primary heat network water first serves as a driving heat source and enters the single-effect lithium bromide absorption heat pump and the semi-effect lithium bromide absorption heat pump of the thermal power station in sequence; then, it serves as a heating heat source and enters the third water-water heat exchanger; finally, it serves as a low-temperature heat source and enters the third evaporator of the second single-effect lithium bromide absorption heat pump and the fourth evaporator of the semi-effect lithium bromide absorption heat pump in sequence; the secondary heat network return water is divided into three paths and connected in parallel to enter the third water-water heat exchanger, the second single-effect lithium bromide absorption heat pump, and the semi-effect lithium bromide absorption heat pump, where it is heated and then merged; then, it serves as secondary water supply and enters the secondary heat network water supply pipeline; The first double-effect lithium bromide absorption heat pump is on all year round; When the heat load changes from small to large, the first water-water heat exchanger, the second double-effect lithium bromide absorption heat pump, the first single-effect lithium bromide absorption heat pump, the large-capacity heat storage module, and the low-pressure steam-water heat exchanger of the heat source station are put into operation in sequence.

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