Coal gasification combined cycle unit

Abstract

The coal gasification combined cycle unit comprises a coal gasification system, a gas power generation system, a steam power generation system and a heat storage system; the gas inlet end of the gas power generation system is connected with the gas outlet end of the coal gasification system; the coal gasification system is used for converting coal into combustible gas; the gas power generation system is used for generating power by using the combustible gas; the heat storage system is used for heating liquid inlet steam of the steam power generation system into steam by using the exhaust heat of the coal gasification system and the exhaust heat of the gas power generation system; and the steam power generation system is used for generating power by using the steam. In the coal gasification combined cycle unit, the exhaust heat of the combustible gas at the gas outlet end of the coal gasification system and the exhaust heat of the exhaust gas at the gas outlet end of the gas power generation system can be fully utilized, the power generation cost is reduced, the comprehensive efficiency is improved, the decoupling of the gas power generation system and the steam power generation system can be realized, the flexible operation of the coal gasification combined cycle unit is facilitated, and the peak shaving demand can be met.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of power generation, in particular to a coal gasification combined cycle unit. BACKGROUND

[0002] With the promotion of energy low-carbon transformation, large-scale wind and light renewable energy has been rapidly developed, the penetration ratio of renewable energy in the power grid has been increasing year by year and will gradually dominate, and the residual load between supply and demand is compensated by traditional power generation mode, therefore, the coal gasification combined cycle unit needs to improve its flexibility to adapt to the development trend of the power market. SUMMARY

[0003] The present disclosure aims to at least partially solve one of the technical problems in the related art.

[0004] To this end, the purpose of the present disclosure is to provide a coal gasification combined cycle unit.

[0005] To achieve the above-mentioned purpose, the present disclosure provides a coal gasification combined cycle unit, comprising: a coal gasification system, a gas power generation system, a steam power generation system and a heat storage system; wherein the gas inlet end of the gas power generation system is connected with the gas outlet end of the coal gasification system, the coal gasification system is used for converting coal into combustible gas, and the gas power generation system is used for generating power by using the combustible gas; the heat storage system is arranged between the gas outlet path of the coal gasification system and the liquid inlet path of the steam power generation system and between the gas outlet path of the gas power generation system and the liquid inlet path of the steam power generation system, the heat storage system is used for heating the liquid inlet of the steam power generation system into steam by using the exhaust heat of the gas outlet of the coal gasification system and the exhaust heat of the gas outlet of the gas power generation system, and the steam power generation system is used for generating power by using the steam.

[0006] Optionally, the heat storage system comprises: a first heat storage tank, a first cold storage tank, a first heat exchanger and a second heat exchanger; wherein the liquid outlet end of the first heat storage tank is connected with the heat release channel liquid inlet end of the steam power generation system, the liquid inlet end of the first cold storage tank is connected with the heat release channel liquid outlet end of the steam power generation system, the heat release channel of the steam power generation system and the heat absorption channel of the steam power generation system are used for heat exchange, the heat absorption channel liquid inlet of the steam power generation system is used for converting into the steam; the heat absorption channel liquid inlet end of the first heat exchanger is connected with the liquid outlet end of the first cold storage tank, the heat absorption channel liquid outlet end of the first heat exchanger is connected with the liquid inlet end of the first heat storage tank, the heat release channel of the first heat exchanger is connected in series at the gas outlet end of the coal gasification system, the heat absorption channel and the heat release channel of the first heat exchanger are used for heat exchange; the heat absorption channel liquid inlet end of the second heat exchanger is connected with the liquid outlet end of the first cold storage tank, the heat absorption channel liquid outlet end of the second heat exchanger is connected with the liquid inlet end of the first heat storage tank, the heat release channel of the second heat exchanger is connected in series at the gas outlet end of the gas power generation system, the heat absorption channel and the heat release channel of the second heat exchanger are used for heat exchange.

[0007] Optionally, the heat storage system further comprises: a second heat storage tank, a second cold storage tank, a third heat exchanger and a fourth heat exchanger; wherein the heat absorption channel liquid inlet end of the third heat exchanger is connected with the liquid outlet end of the second cold storage tank, the heat absorption channel liquid outlet end of the third heat exchanger is connected with the liquid inlet end of the second heat storage tank, the heat release channel of the third heat exchanger is connected in series at the heat release channel gas outlet end of the second heat exchanger, the heat absorption channel and the heat release channel of the third heat exchanger are used for heat exchange; the heat release channel liquid inlet end of the fourth heat exchanger is connected with the liquid outlet end of the second heat storage tank, the heat release channel liquid outlet end of the fourth heat exchanger is connected with the liquid inlet end of the second cold storage tank, the heat absorption channel of the fourth heat exchanger is connected in series at the heat absorption channel liquid inlet end of the steam power generation system, the heat absorption channel and the heat release channel of the fourth heat exchanger are used for heat exchange.

[0008] Optionally, the heat storage system further comprises: a fifth heat exchanger, the heat absorption channel liquid inlet end of the fifth heat exchanger is connected with the liquid outlet end of the first cold storage tank, the heat absorption channel liquid outlet end of the fifth heat exchanger is connected with the liquid inlet end of the first heat storage tank, the heat release channel of the fifth heat exchanger is connected in series at the heat release channel gas outlet end of the first heat exchanger, the heat absorption channel and the heat release channel of the fifth heat exchanger are used for heat exchange.

[0009] Optionally, the coal gasification combined cycle unit further comprises: an electrochemical energy storage system, the power supply end of the electrochemical energy storage system is connected with the power supply end of the gas power generation system and the power supply end of the steam power generation system respectively; wherein the power supply end of the electrochemical energy storage system, the power supply end of the gas power generation system and the power supply end of the steam power generation system are connected with the power supply end of the power grid respectively.

[0010] Optionally, the coal gasification system comprises: an oxygen tank, a coal gasification furnace, a condensing and purifying device, and a combustible gas tank; wherein, the gas outlet of the oxygen tank is connected with the gas inlet of the coal gasification furnace, the gas outlet of the coal gasification furnace is connected with the gas inlet of the condensing and purifying device, the gas outlet of the condensing and purifying device is connected with the gas inlet of the combustible gas tank, and the gas outlet of the combustible gas tank is connected with the gas inlet of the gas power generation system; the heat storage system is arranged between the gas outlet path of the coal gasification furnace and the liquid inlet path of the steam power generation system, and the heat storage system is used for heating the liquid inlet of the steam power generation system into steam by using the waste heat of the gas outlet of the coal gasification furnace.

[0011] Optionally, the coal gasification system further comprises: an air separation device and a nitrogen tank, the nitrogen gas outlet of the air separation device is connected with the gas inlet of the nitrogen tank, and the oxygen gas outlet of the air separation device is connected with the gas inlet of the oxygen tank.

[0012] Optionally, the gas power generation system comprises: a compressor, a combustion chamber, a gas turbine, and a gas power generator; wherein, the gas inlets of the combustion chamber are connected with the gas outlet of the coal gasification system and the gas outlet of the compressor respectively, the gas outlet of the combustion chamber is connected with the gas inlet of the gas turbine, and the power output end of the gas turbine is connected with the power input end of the compressor and the power input end of the gas power generator respectively.

[0013] Optionally, the steam power generation system comprises: a steam generator, the heat storage system is arranged between the gas outlet path of the coal gasification system and the heat absorption channel of the steam generator and between the gas outlet path of the gas power generation system and the heat absorption channel of the steam generator, and the heat storage system is used for heating the liquid inlet of the heat absorption channel of the steam generator into the steam by using the waste heat of the gas outlet of the coal gasification system and the waste heat of the gas outlet of the gas power generation system; a steam turbine, the steam inlet of the steam turbine is connected with the steam outlet of the heat absorption channel of the steam generator.

[0014] Optionally, the steam power generation system further comprises: a condenser, the steam inlet of the condenser is connected with the steam outlet of the steam turbine, and the liquid outlet of the condenser is connected with the liquid inlet of the heat absorption channel of the steam generator.

[0015] The technical scheme provided by the present disclosure can have the following beneficial effects:

[0016] The combustible gas generated by the coal gasification system can be transported into the gas power generation system, so that the gas power generation system can generate power by using the combustible gas. Meanwhile, the heat storage system is arranged between the gas outlet path of the coal gasification system and the liquid inlet path of the steam power generation system, and between the gas outlet path of the gas power generation system and the liquid inlet path of the steam power generation system, so that the heat storage system can conduct the waste heat of the gas outlet of the coal gasification system and the waste heat of the gas outlet of the gas power generation system to the liquid inlet of the steam power generation system, so that the liquid inlet of the steam power generation system is converted into steam, and then the steam power generation system can generate power by using the steam. In this way, the power generation of the gas power generation system and the steam power generation system can meet the larger power demand. Meanwhile, the heat storage and heat release of the heat storage system can not only fully utilize the waste heat of the combustible gas outlet of the coal gasification system and the waste heat of the exhaust gas outlet of the gas power generation system, reduce the power generation cost, and improve the comprehensive efficiency, but also realize the decoupling of the gas power generation system and the steam power generation system, so as to facilitate the flexible operation of the coal gasification combined cycle unit, and then meet the peak shaving demand.

[0017] Additional aspects and advantages of the present disclosure will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and / or additional aspects and advantages of the present disclosure will become apparent and be readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 is a structural schematic diagram of a coal gasification combined cycle unit according to an embodiment of the present disclosure;

[0020] Figure 2 is a structural schematic diagram of a coal gasification combined cycle unit according to an embodiment of the present disclosure;

[0021] As shown in the figure: 1, coal gasification system, 11, oxygen storage tank, 12, coal gasification furnace, 13, condensation purification device, 14, combustible gas storage tank, 15, air separation device, 16, nitrogen storage tank;

[0022] 2, gas power generation system, 21, air compressor, 22, combustion chamber, 23, gas turbine, 24, gas generator;

[0023] 3, steam power generation system, 31, steam generator, 32, steam turbine, 33, condenser;

[0024] 4. Heat storage system, 41. First hot storage tank, 42. First cold storage tank, 43. First heat exchanger, 44. Second heat exchanger, 45. Second hot storage tank, 46. Second cold storage tank, 47. Third heat exchanger, 48. Fourth heat exchanger, 49. Fifth heat exchanger;

[0025] 5. Electrochemical energy storage system. DETAILED DESCRIPTION

[0026] Embodiments of the present disclosure are described in detail below with reference to examples illustrated in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are for the purpose of explanation only, and are not to be understood as limiting the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.

[0027] As shown in Figure 1 The coal gasification combined cycle unit according to the present disclosure comprises a coal gasification system 1, a gas power generation system 2, a steam power generation system 3 and a heat storage system 4; wherein the gas inlet end of the gas power generation system 2 is connected with the gas outlet end of the coal gasification system 1, the coal gasification system 1 is used to convert coal into combustible gas, the gas power generation system 2 is used to generate power by using the combustible gas, the heat storage system 4 is arranged between the gas outlet path of the coal gasification system 1 and the liquid inlet path of the steam power generation system 3 and between the gas outlet path of the gas power generation system 2 and the liquid inlet path of the steam power generation system 3, the heat storage system 4 is used to heat the liquid inlet of the steam power generation system 3 into steam by using the exhaust heat of the gas outlet of the coal gasification system 1 and the exhaust heat of the gas outlet of the gas power generation system 2, and the steam power generation system 3 is used to generate power by using the steam.

[0028] It can be understood that, since the gas inlet end of the gas power generation system 2 is connected with the gas outlet end of the coal gasification system 1, the combustible gas generated by the coal gasification system 1 can be transported into the gas power generation system 2, so that the gas power generation system 2 can generate power by using the combustible gas. Meanwhile, since the heat storage system 4 is arranged between the gas outlet path of the coal gasification system 1 and the liquid inlet path of the steam power generation system 3 and between the gas outlet path of the gas power generation system 2 and the liquid inlet path of the steam power generation system 3, the heat storage system 4 can conduct the exhaust heat of the gas outlet of the coal gasification system 1 and the exhaust heat of the gas outlet of the gas power generation system 2 to the liquid inlet of the steam power generation system 3, so that the liquid inlet of the steam power generation system 3 is converted into steam, and then the steam power generation system 3 can generate power by using the steam.

[0029] Thus, the power generation of the gas-fired power generation system 2 and the steam power generation system 3 can meet the larger power demand, and the heat storage and release of the heat storage system 4 can not only fully utilize the waste heat of the combustible gas at the gas outlet end of the coal gasification system 1 and the waste heat of the exhaust gas at the gas outlet end of the gas-fired power generation system 2, reduce the power generation cost, and improve the comprehensive efficiency, but also realize the decoupling of the gas-fired power generation system 2 and the steam power generation system 3, thereby facilitating the flexible operation of the coal gasification combined cycle unit and further meeting the peak shaving demand.

[0030] It should be noted that the flexible operation mode of the coal gasification combined cycle unit can be set according to actual needs, and is not limited, for example:

[0031] When the power demand is small, the coal gasification system 1 is operated alone, and the gas-fired power generation system 2 and the steam power generation system 3 are not operated, so that the coal gasification system 1 can produce combustible gas and store the combustible gas, and the waste heat in the combustible gas can be stored by the heat storage system 4.

[0032] When the power demand increases, the coal gasification system 1 and the gas-fired power generation system 2 are operated, and the steam power generation system 3 is not operated, so that the coal gasification system 1 can produce combustible gas and deliver the combustible gas to the gas-fired power generation system 2 to make the gas-fired power generation system 2 generate power by using the combustible gas, and the waste heat of the combustible gas at the gas outlet end of the coal gasification system 1 and the waste heat of the exhaust gas at the gas outlet end of the gas-fired power generation system 2 can be stored by the heat storage system 4.

[0033] When the power demand is large, the coal gasification system 1, the gas-fired power generation system 2 and the steam power generation system 3 are operated, so that the coal gasification system 1 can produce combustible gas and deliver the combustible gas to the gas-fired power generation system 2 to make the gas-fired power generation system 2 generate power by using the combustible gas, and the waste heat of the combustible gas at the gas outlet end of the coal gasification system 1 and the waste heat of the exhaust gas at the gas outlet end of the gas-fired power generation system 2 are released into the liquid inlet of the steam power generation system 3 by the heat storage system 4, so that the liquid inlet of the steam power generation system 3 is converted into steam and generates power. Among them, the waste heat of the exhaust gas at the gas outlet end of the gas-fired power generation system 2 can be used for preheating the liquid inlet of the steam power generation system 3, and the waste heat of the combustible gas at the gas outlet end of the coal gasification system 1 can be used for heating the liquid inlet of the steam power generation system 3 into steam capable of generating power, so that the setting of the heat storage system 4 realizes the cascade storage and utilization of heat energy, and promotes the clean utilization of coal resources.

[0034] Among them, the coal gasification system 1 can be operated alone to realize the decoupling of the coal gasification system 1 and the gas-fired power generation system 2, thereby reducing the design capacity of the coal gasification system 1 and further reducing the engineering construction cost of the coal gasification combined cycle unit.

[0035] Coal gasification system 1 is used to convert coal into combustible gas. Coal gasification, also known as coal gasification, refers to the process of thermochemically processing coal with a gasifying agent under certain temperature and pressure conditions, converting the organic matter in the coal into combustible gas. Specifically, coal gasification is a multiphase reaction process that uses coal, semi-coke, or coke as raw materials, and air, oxygen-enriched gas, water vapor, carbon dioxide, or hydrogen as gasification media. This process involves partial oxidation and reduction reactions in the coal, converting its carbon and hydrogen content into gaseous products mainly composed of combustible components such as carbon monoxide, hydrogen, and methane. The specific type of coal gasification system 1 can be set according to actual needs and is not limited thereto.

[0036] The gas-fired power generation system 2 is used to generate electricity using combustible gas. The specific type of the gas-fired power generation system 2 can be set according to actual needs and there are no restrictions on it.

[0037] Steam power generation system 3 is used to generate electricity using steam. The specific type of steam power generation system 3 can be set according to actual needs and there are no restrictions on it.

[0038] The thermal storage system 4 is used to store the waste heat of combustible gas at the outlet of the coal gasification system 1 and the waste heat of exhaust gas at the outlet of the gas-fired power generation system 2, and to release the stored heat into the liquid inlet of the steam power generation system 3. The specific type of the thermal storage system 4 can be set according to actual needs and is not limited thereto.

[0039] like Figure 2 As shown, in some embodiments, the thermal storage system 4 includes: a first hot storage tank 41, a first cold storage tank 42, a first heat exchanger 43, and a second heat exchanger 44; wherein, the liquid outlet of the first hot storage tank 41 is connected to the liquid inlet of the heat release channel of the steam power generation system 3, the liquid inlet of the first cold storage tank 42 is connected to the liquid outlet of the heat release channel of the steam power generation system 3, the heat release channel of the steam power generation system 3 and the heat absorption channel of the steam power generation system 3 are used for heat exchange, the liquid inlet of the heat absorption channel in the steam power generation system 3 is used to convert into steam, and the liquid inlet of the heat absorption channel of the first heat exchanger 43 is connected to the liquid outlet of the first cold storage tank 42. The heat exchangers are connected at both ends. The liquid outlet of the heat absorption channel of the first heat exchanger 43 is connected to the liquid inlet of the first hot storage tank 41. The heat release channel of the first heat exchanger 43 is connected in series to the gas outlet of the coal gasification system 1. The heat exchangers 43 are used for heat exchange between the heat absorption channel and the heat release channel. The liquid inlet of the heat absorption channel of the second heat exchanger 44 is connected to the liquid outlet of the first cold storage tank 42. The liquid outlet of the heat absorption channel of the second heat exchanger 44 is connected to the liquid inlet of the first hot storage tank 41. The heat release channel of the second heat exchanger 44 is connected in series to the gas outlet of the gas-fired power generation system 2. The heat exchangers 44 are used for heat exchange between the heat absorption channel and the heat release channel.

[0040] It can be understood that, since the liquid inlet end of the heat absorption channel of the first heat exchanger 43 is connected with the liquid outlet end of the first cold storage tank 42, and the liquid outlet end of the heat absorption channel of the first heat exchanger 43 is connected with the liquid inlet end of the first hot storage tank 41, the fluid medium in the first cold storage tank 42 can enter the first hot storage tank 41 through the heat absorption channel of the first heat exchanger 43, and since the heat release channel of the first heat exchanger 43 is connected in series with the gas outlet end of the coal gasification system 1, the waste heat of the combustible gas at the gas outlet end of the coal gasification system 1 can be released into the fluid medium in the heat absorption channel through the heat release channel of the first heat exchanger 43 when the fluid medium passes through the heat absorption channel of the first heat exchanger 43, so that the waste heat of the combustible gas is stored in the first hot storage tank 41 by using the fluid medium.

[0041] At the same time, since the liquid outlet end of the heat absorption channel of the second heat exchanger 44 is connected with the liquid inlet end of the first hot storage tank 41, and the heat release channel of the second heat exchanger 44 is connected in series with the gas outlet end of the gas power generation system 2, the fluid medium in the first cold storage tank 42 can enter the first hot storage tank 41 through the heat absorption channel of the second heat exchanger 44, and since the heat release channel of the second heat exchanger 44 is connected in series with the gas outlet end of the gas power generation system 2, the waste heat of the exhaust gas at the gas outlet end of the gas power generation system 2 can be released into the fluid medium in the heat absorption channel through the heat release channel of the second heat exchanger 44 when the fluid medium passes through the heat absorption channel of the second heat exchanger 44, so that the waste heat of the exhaust gas is stored in the first hot storage tank 41 by using the fluid medium.

[0042] In which, since the liquid outlet end of the first hot storage tank 41 is connected with the liquid inlet end of the heat absorption channel of the steam power generation system 3, and the liquid inlet end of the first cold storage tank 42 is connected with the liquid outlet end of the heat absorption channel of the steam power generation system 3, the fluid medium in the first hot storage tank 41 can enter the first cold storage tank 42 through the heat absorption channel of the steam power generation system 3, and when the fluid medium passes through the heat absorption channel of the steam power generation system 3, it can release heat to the fluid medium in the heat absorption channel of the steam power generation system 3, so that the liquid inlet in the heat absorption channel of the steam power generation system 3 is converted into steam, thereby realizing power generation of the steam power generation system 3, and the fluid medium after heat release can return to the first cold storage tank 42 for the next heat exchange cycle.

[0043] It should be noted that the first hot storage tank 41 is used to store the fluid medium after absorbing heat, and the specific type of the first hot storage tank 41 can be set according to actual needs, which is not limited, for example, the first hot storage tank 41 is a large-capacity tank structure.

[0044] The first cold storage tank 42 is used to store the fluid medium after releasing heat, and the specific type of the first cold storage tank 42 can be set according to actual needs, which is not limited, for example, the first cold storage tank 42 is a large-capacity tank structure.

[0045] The first heat exchanger 43 is used for heat exchange between the combustible gas at the outlet of the coal gasification system 1 and the fluid medium from the first cold storage tank 42 to the first hot storage tank 41. The first heat exchanger 43 includes a heat absorption channel and a heat release channel. The specific type of the first heat exchanger 43 can be set according to actual needs and is not limited thereto. For example, the first heat exchanger 43 can be a radiation heat exchanger, etc.

[0046] The second heat exchanger 44 is used for heat exchange between the exhaust gas at the outlet of the gas-fired power generation system 2 and the fluid medium between the first cold storage tank 42 and the first hot storage tank 41. The second heat exchanger 44 includes a heat absorption channel and a heat release channel. The specific type of the second heat exchanger 44 can be set according to actual needs and is not limited thereto. For example, the second heat exchanger 44 can be a waste heat exchanger, etc.

[0047] The fluid medium is used to store and release heat. The specific type of fluid medium can be set according to actual needs and is not limited thereto. For example, the fluid medium can be molten salt.

[0048] like Figure 2 As shown, in some embodiments, the thermal storage system 4 further includes: a second hot storage tank 45, a second cold storage tank 46, a third heat exchanger 47, and a fourth heat exchanger 48; wherein, the liquid inlet end of the heat absorption channel of the third heat exchanger 47 is connected to the liquid outlet end of the second cold storage tank 46, the liquid outlet end of the heat absorption channel of the third heat exchanger 47 is connected to the liquid inlet end of the second hot storage tank 45, the heat release channel of the third heat exchanger 47 is connected in series to the gas outlet end of the heat release channel of the second heat exchanger 44, and the heat absorption channel and the heat release channel of the third heat exchanger 47 are used for heat exchange; the liquid inlet end of the heat release channel of the fourth heat exchanger 48 is connected to the liquid outlet end of the second hot storage tank 45, the liquid outlet end of the heat release channel of the fourth heat exchanger 48 is connected to the liquid inlet end of the second cold storage tank 46, the heat absorption channel of the fourth heat exchanger 48 is connected in series to the liquid inlet end of the heat absorption channel of the steam power generation system 3, and the heat absorption channel and the heat release channel of the fourth heat exchanger 48 are used for heat exchange.

[0049] It is understandable that, since the liquid inlet end of the heat absorption channel of the third heat exchanger 47 is connected to the liquid outlet end of the second cold storage tank 46, and the liquid outlet end of the heat absorption channel of the third heat exchanger 47 is connected to the liquid inlet end of the second hot storage tank 45, the fluid medium in the second cold storage tank 46 can enter the second hot storage tank 45 through the heat absorption channel of the third heat exchanger 47. Furthermore, since the heat release channel of the third heat exchanger 47 is connected in series with the gas outlet end of the heat release channel of the second heat exchanger 44, when the fluid medium passes through the heat absorption channel of the third heat exchanger 47, the waste heat of the exhaust gas at the gas outlet end of the gas-fired power generation system 2 can be released into the fluid medium in the heat absorption channel through the heat release channel of the third heat exchanger 47, thereby utilizing the fluid medium to realize the storage of waste heat of exhaust gas in the second hot storage tank 45.

[0050] Meanwhile, since the liquid inlet end of the heat releasing channel of the fourth heat exchanger 48 is connected with the liquid outlet end of the second hot storage tank 45, and the liquid outlet end of the heat releasing channel of the fourth heat exchanger 48 is connected with the liquid inlet end of the second cold storage tank 46, the fluid medium in the second hot storage tank 45 can enter the second cold storage tank 46 through the heat releasing channel of the fourth heat exchanger 48, and since the heat absorbing channel of the fourth heat exchanger 48 is connected in series with the liquid inlet end of the heat absorbing channel of the steam power generation system 3, when the fluid medium passes through the heat releasing channel of the fourth heat exchanger 48, it can release heat into the heat absorbing channel of the fourth heat exchanger 48, so as to preheat the liquid entering the heat absorbing channel of the steam power generation system 3, and the fluid medium after releasing heat can return to the second cold storage tank 46, so as to carry out the next heat exchange cycle.

[0051] In addition, the second heat exchanger 44 and the third heat exchanger 47 constitute a two-stage heat exchange structure at the gas outlet end of the gas power generation system 2, not only fully utilizing the waste heat of the gas power generation system 2, but also making the gas power generation system 2 have a lower exhaust gas temperature, thereby improving the overall comprehensive efficiency.

[0052] It should be noted that the second hot storage tank 45 is used for storing the fluid medium after absorbing heat, and the specific type of the second hot storage tank 45 can be set according to actual needs, which is not limited, for example, the second hot storage tank 45 is a large-capacity tank structure.

[0053] The second cold storage tank 46 is used for storing the fluid medium after releasing heat, and the specific type of the second cold storage tank 46 can be set according to actual needs, which is not limited, for example, the second cold storage tank 46 is a large-capacity tank structure.

[0054] The third heat exchanger 47 is used for heat exchange between the exhaust gas at the gas outlet end of the gas power generation system 2 and the fluid medium from the second cold storage tank 46 to the second hot storage tank 45, and the third heat exchanger 47 includes a heat absorbing channel and a heat releasing channel. The specific type of the third heat exchanger 47 can be set according to actual needs, which is not limited, for example, the third heat exchanger 47 can be a waste heat exchanger.

[0055] The fourth heat exchanger 48 is used for heat exchange between the liquid entering the heat absorbing channel of the steam power generation system 3 and the fluid medium from the second hot storage tank 45 to the second cold storage tank 46, and the fourth heat exchanger 48 includes a heat absorbing channel and a heat releasing channel. The specific type of the fourth heat exchanger 48 can be set according to actual needs, which is not limited, for example, the fourth heat exchanger 48 can be a preheating heat exchanger.

[0056] As Figure 2As shown, in some embodiments, the heat storage system 4 further comprises: a fifth heat exchanger 49, a liquid inlet end of an endothermic channel of the fifth heat exchanger 49 is connected with a liquid outlet end of the first cold storage tank 42, a liquid outlet end of the endothermic channel of the fifth heat exchanger 49 is connected with a liquid inlet end of the first hot storage tank 41, a heat releasing channel of the fifth heat exchanger 49 is connected in series with a gas outlet end of the heat releasing channel of the first heat exchanger 43, and the endothermic channel and the heat releasing channel of the fifth heat exchanger 49 are used for heat exchange.

[0057] It can be understood that, since the liquid inlet end of the endothermic channel of the fifth heat exchanger 49 is connected with the liquid outlet end of the first cold storage tank 42, and the liquid outlet end of the endothermic channel of the fifth heat exchanger 49 is connected with the liquid inlet end of the first hot storage tank 41, the fluid medium in the first cold storage tank 42 can enter the first hot storage tank 41 through the endothermic channel of the fifth heat exchanger 49, and since the heat releasing channel of the fifth heat exchanger 49 is connected in series with the gas outlet end of the heat releasing channel of the first heat exchanger 43, the waste heat of the combustible gas at the gas outlet end of the coal gasification system 1 can be released into the fluid medium in the endothermic channel through the heat releasing channel of the fifth heat exchanger 49 when the fluid medium passes through the endothermic channel of the fifth heat exchanger 49, so that the storage of the waste heat of the combustible gas into the first hot storage tank 41 is realized by using the fluid medium.

[0058] In the coal gasification system 1, the first heat exchanger 43 and the fifth heat exchanger 49 constitute a two-stage heat exchange structure at the gas outlet end of the coal gasification system 1, the waste heat of the combustible gas of the coal gasification system 1 is fully utilized, and the overall comprehensive efficiency is improved.

[0059] It should be noted that the fifth heat exchanger 49 is used for heat exchange between the combustible gas at the gas outlet end of the coal gasification system 1 and the fluid medium from the first cold storage tank 42 to the first hot storage tank 41, the fifth heat exchanger 49 comprises an endothermic channel and a heat releasing channel, and the specific type of the fifth heat exchanger 49 can be set according to actual needs, which is not limited, for example, the fifth heat exchanger 49 can be a counterflow heat exchanger.

[0060] As shown in the coal gasification combined cycle unit, Figure 2 As shown, in some embodiments, the coal gasification combined cycle unit further comprises: an electrochemical energy storage system 5, power supply ends of the electrochemical energy storage system 5 are connected with power supply ends of the gas power generation system 2 and the steam power generation system 3 respectively; wherein, the power supply ends of the electrochemical energy storage system 5, the power supply ends of the gas power generation system 2 and the power supply ends of the steam power generation system 3 are connected with power supply ends of a power grid respectively.

[0061] Understandably, since the power supply terminals of the electrochemical energy storage system 5 are connected to the power supply terminals of the gas-fired power generation system 2 and the steam power generation system 3, respectively, and the power supply terminals of the gas-fired power generation system 2 and the steam power generation system 3 are connected to the power supply terminals of the power grid, the gas-fired power generation system 2 and the steam power generation system 3 can supply power to the electrochemical energy storage system 5 and the power grid, respectively. Thus, the electrochemical energy storage system 5 can store excess electrical energy. At the same time, since the power supply terminals of the electrochemical energy storage system 5 are connected to the power supply terminals of the power grid, the electrochemical energy storage system 5 can supply power to the power grid. This not only meets the large electricity demand, but also effectively improves the frequency regulation performance of the coal gasification combined cycle unit by utilizing the rapid response and bidirectional regulation capabilities of the electrochemical energy storage system 5.

[0062] It should be noted that the electrochemical energy storage system 5 is used for the storage and release of electrical energy. The specific type of the electrochemical energy storage system 5 can be set according to actual needs and is not limited thereto. For example, the electrochemical energy storage system 5 can be a battery system. The coupling of the electrochemical energy storage system 5 with the gas-fired power generation system 2 and the steam power generation system 3 effectively improves the frequency regulation response capability of the coal gasification combined cycle unit.

[0063] like Figure 2 As shown, in some embodiments, the coal gasification system 1 includes: an oxygen storage tank 11, a coal gasifier 12, a condensation and purification device 13, and a combustible gas storage tank 14; wherein, the outlet of the oxygen storage tank 11 is connected to the inlet of the coal gasifier 12, the outlet of the coal gasifier 12 is connected to the inlet of the condensation and purification device 13, the outlet of the condensation and purification device 13 is connected to the inlet of the combustible gas storage tank 14, the outlet of the combustible gas storage tank 14 is connected to the inlet of the gas-fired power generation system 2, and the heat storage system 4 is disposed between the outlet path of the coal gasifier 12 and the liquid inlet path of the steam power generation system 3. The heat storage system 4 is used to heat the liquid inlet of the steam power generation system 3 into steam using the waste heat from the outlet of the coal gasifier 12.

[0064] Understandably, since the outlet of the oxygen storage tank 11 is connected to the inlet of the coal gasifier 12, and the outlet of the coal gasifier 12 is connected to the inlet of the condensation and purification device 13, and the outlet of the condensation and purification device 13 is connected to the inlet of the combustible gas storage tank 14, the coal gasifier 12 can use the oxygen in the oxygen storage tank 11 to convert coal into combustible gas and use the condensation and purification device 13 to condense and purify the combustible gas, while using the combustible gas storage tank 14 to store the combustible gas.

[0065] Since the outlet of the combustible gas storage tank 14 is connected to the inlet of the gas power generation system 2, the gas power generation system 2 can generate electricity using combustible gas, thereby meeting the electricity demand. Since the heat storage system 4 is set between the outlet path of the coal gasifier 12 and the inlet path of the steam power generation system 3, the heat storage system 4 can use the waste heat from the outlet of the coal gasifier 12 to heat the inlet liquid of the steam power generation system 3 into steam, thereby enabling the steam power generation system 3 to generate electricity using steam, thereby meeting the electricity demand.

[0066] It should be noted that the heat absorption channels of the first heat exchanger 43 and the fifth heat exchanger 49 are connected in series between the gas outlet of the coal gasifier 12 and the gas inlet of the condensation and purification device 13. The fluid medium in the heat release channels of the first heat exchanger 43 and the fifth heat exchanger 49 absorbs the heat from the combustible gas in sequence.

[0067] Oxygen storage tank 11 is used to store oxygen. The specific type of oxygen storage tank 11 can be set according to actual needs and there is no restriction. For example, oxygen storage tank 11 can be a tank structure with a large volume.

[0068] The coal gasifier 12 is used to convert coal into combustible gas. The specific type of coal gasifier 12 can be set according to actual needs and there is no restriction. For example, the coal gasifier 12 can be a fixed bed gasifier, a fluidized bed gasifier, an entrained flow coal gasifier 12, etc.

[0069] The condensation purification device 13 is used for the condensation and purification of combustible gases. The specific type of the condensation purification device 13 can be set according to actual needs and is not limited thereto. For example, the condensation purification device 13 can be a washing cooler, etc.

[0070] The combustible gas storage tank 14 is used to store combustible gas, and when the electricity demand increases and the gas power generation system 2 is turned on, the combustible gas storage tank 14 is used to supply combustible gas to the gas power generation system. The specific type of the combustible gas storage tank 14 can be set according to actual needs and there is no restriction. For example, the combustible gas storage tank 14 can be a tank structure with a large volume.

[0071] like Figure 2 As shown, in some embodiments, the coal gasification system 1 further includes an air separation device 15 and a nitrogen storage tank 16, wherein the nitrogen outlet of the air separation device 15 is connected to the inlet of the nitrogen storage tank 16, and the oxygen outlet of the air separation device 15 is connected to the inlet of the oxygen storage tank 11.

[0072] It is understandable that, since the nitrogen outlet of the air separator 15 is connected to the inlet of the nitrogen storage tank 16, and the oxygen outlet of the air separator 15 is connected to the inlet of the oxygen storage tank 11, the nitrogen separated by the air separator 15 can be stored in the nitrogen tank, and the oxygen separated can be stored in the oxygen tank. This facilitates the flexible and stable use of nitrogen and oxygen.

[0073] It should be noted that the air separation device 15 is used to separate oxygen and nitrogen from the air. The specific type of the air separation device 15 can be set according to actual needs and there are no restrictions on it.

[0074] Nitrogen storage tank 16 is used to store nitrogen. The specific type of nitrogen storage tank 16 can be set according to actual needs and there is no restriction. For example, nitrogen storage tank 16 can be a tank structure with a large volume.

[0075] like Figure 2 As shown, in some embodiments, the gas-fired power generation system 2 includes: a compressor 21, a combustion chamber 22, a gas turbine 23, and a gas generator 24; wherein, the air inlet of the combustion chamber 22 is connected to the air outlet of the coal gasification system 1 and the air outlet of the compressor 21, the air outlet of the combustion chamber 22 is connected to the air inlet of the gas turbine 23, and the power output end of the gas turbine 23 is connected to the power input end of the compressor 21 and the power input end of the gas generator 24.

[0076] Understandably, since the air inlet of the combustion chamber 22 is connected to the air outlet of the coal gasification system 1 and the air outlet of the compressor 21 respectively, and the air outlet of the combustion chamber 22 is connected to the air inlet of the gas turbine 23, and the power output of the gas turbine 23 is connected to the power input of the compressor 21 and the power input of the gas generator 24 respectively, the combustion chamber 22 can use the compressed air provided by the compressor 21 and the combustible gas provided by the coal gasification system 1 to achieve combustion and deliver high-temperature and high-pressure gas to the gas turbine 23, so that the gas turbine 23 can use the high-temperature and high-pressure gas to drive the compressor 21 and the gas generator 24 to operate, thereby realizing power generation and meeting the electricity demand.

[0077] It should be noted that the gas-fired power generation system 2 converts chemical energy into mechanical energy, and then converts mechanical energy into electrical energy. The exhaust gas discharged from the gas turbine 23 is used to heat the fluid medium using the second heat exchanger 44 and the third heat exchanger 47. Specifically, the outlet end of the gas turbine 23 is connected to the inlet end of the heat absorption channel of the second heat exchanger 44, and the outlet end of the heat absorption channel of the second heat exchanger 44 is connected to the inlet end of the heat absorption channel of the third heat exchanger 47.

[0078] The compressor 21 is used to supply compressed air to the combustion chamber 22. The specific type of compressor 21 can be set according to actual needs and there is no restriction on it.

[0079] Combustion chamber 22 is used for the combustion of combustible gases. The specific type of combustion chamber 22 can be set according to actual needs and there are no restrictions on it.

[0080] The gas turbine 23 is used to output mechanical energy from high-temperature and high-pressure gas and drive the compressor 21 and the gas generator 24. The specific type of gas turbine 23 can be set according to actual needs and there are no restrictions on it.

[0081] The gas generator 24 is used to convert mechanical energy into electrical energy. The specific type of the gas generator 24 can be set according to actual needs and there are no restrictions on it.

[0082] like Figure 2 As shown, in some embodiments, the steam power generation system 3 includes a steam generator 31 and a steam turbine 32. A heat storage system 4 is disposed between the gas outlet path of the coal gasification system 1 and the heat release channel of the steam generator 31, and between the gas outlet path of the gas power generation system 2 and the heat absorption channel of the steam generator 31. The heat storage system 4 is used to heat the liquid inlet of the heat absorption channel of the steam generator 31 into steam by utilizing the waste heat from the gas outlet of the coal gasification system 1 and the waste heat from the gas outlet of the gas power generation system 2. The steam inlet end of the steam turbine 32 is connected to the steam outlet end of the heat absorption channel of the steam generator 31.

[0083] Understandably, since the heat storage system 4 is located between the gas outlet path of the coal gasification system 1 and the heat release channel of the steam generator 31, and between the gas outlet path of the gas power generation system 2 and the heat absorption channel of the steam generator 31, the heat storage system 4 can use the waste heat from the gas outlet of the coal gasification system 1 and the waste heat from the gas outlet of the gas power generation system 2 to heat the liquid inlet of the heat absorption channel of the steam generator 31 into steam. Furthermore, since the steam inlet of the steam turbine 32 is connected to the steam outlet of the heat absorption channel of the steam generator 31, the steam turbine 32 can use the steam generated by the steam generator 31 to generate electricity, thereby meeting the electricity demand.

[0084] It should be noted that the steam generator 31 is used to convert the inlet liquid into steam by utilizing the waste heat from the gasification system 1 and the gas-fired power generation system 2. The steam generator 31 includes a heat absorption channel and a heat release channel. The specific type of the steam generator 31 can be set according to actual needs and is not limited thereto. Specifically, the inlet end of the heat release channel of the steam generator 31 is connected to the outlet end of the first hot storage tank 41, the outlet end of the heat release channel of the steam generator 31 is connected to the inlet end of the first cold storage tank 42, and the inlet end of the heat absorption channel of the steam generator 31 is connected to the outlet end of the heat absorption channel of the fourth heat exchanger 48.

[0085] Steam turbine 32 is used to generate electricity using steam. The specific type of steam turbine 32 can be set according to actual needs and there are no restrictions on it.

[0086] As Figure 2 shown, in some embodiments, the steam power generation system 3 further comprises a condenser 33, a steam inlet end of the condenser 33 is connected with a steam outlet end of the steam turbine 32, and a liquid outlet end of the condenser 33 is connected with a heat absorption passage liquid inlet end of the steam generator 31.

[0087] It can be understood that, since the steam inlet end of the condenser 33 is connected with the steam outlet end of the steam turbine 32, and the liquid outlet end of the condenser 33 is connected with the heat absorption passage liquid inlet end of the steam generator 31, the steam after work in the steam turbine 32 can be condensed into liquid by the condenser 33 and returned to the heat absorption passage of the steam generator 31, so as to realize recycling use and reduce cost.

[0088] It should be noted that the condenser 33 is used for converting steam into liquid, and the specific type of the condenser 33 can be set according to actual needs, and no limitation is made to this. The liquid outlet end of the condenser 33 is connected with the heat absorption passage liquid inlet end of the fourth heat exchanger 48.

[0089] In the description of the present disclosure, the terms "first", "second", and the like are only for descriptive purposes, and cannot be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0090] Any process or method descriptions in flow charts or described elsewhere herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for performing specific logic functions or steps in the process. The various embodiments of the present disclosure can include additional or fewer steps or processes in addition to or other than those of the process described in this specification as a range of embodiments and can be performed in the same order as shown or discussed, in a substantially simultaneous manner, or in a reverse order, as will be apparent to those skilled in the art of the embodiments of the present disclosure.

[0091] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0092] Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present disclosure, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A coal gasification combined cycle unit, characterized in that, include: Coal gasification systems, gas-fired power generation systems, steam power generation systems, and thermal storage systems; The gas-fired power generation system is connected to the gas outlet of the coal gasification system. The coal gasification system is used to convert coal into combustible gas, and the gas-fired power generation system is used to generate electricity using the combustible gas. The thermal storage system is located between the gas outlet path of the coal gasification system and the liquid inlet path of the steam power generation system, as well as between the gas outlet path of the gas power generation system and the liquid inlet path of the steam power generation system. The thermal storage system is used to heat the liquid inlet of the steam power generation system into steam by utilizing the waste heat from the gas outlet of the coal gasification system and the waste heat from the gas outlet of the gas power generation system. The steam power generation system is used to generate electricity by utilizing the steam. The thermal storage system includes: a first hot storage tank, a first cold storage tank, a first heat exchanger, and a second heat exchanger. The outlet of the first hot storage tank is connected to the inlet of the heat release channel of the steam power generation system, and the inlet of the first cold storage tank is connected to the outlet of the heat release channel of the steam power generation system. Heat exchange is performed between the heat release channel and the heat absorption channel of the steam power generation system. The liquid entering the heat absorption channel of the steam power generation system is converted into steam. The inlet of the heat absorption channel of the first heat exchanger is connected to the outlet of the first cold storage tank. The liquid outlet of the heat absorption channel of the first heat exchanger is connected to the liquid inlet of the first hot storage tank. The heat release channel of the first heat exchanger is connected in series at the gas outlet of the coal gasification system. The heat absorption channel and the heat release channel of the first heat exchanger are used for heat exchange. The liquid inlet of the heat absorption channel of the second heat exchanger is connected to the liquid outlet of the first cold storage tank. The liquid outlet of the heat absorption channel of the second heat exchanger is connected to the liquid inlet of the first hot storage tank. The heat release channel of the second heat exchanger is connected in series at the gas outlet of the gas-fired power generation system. The heat absorption channel and the heat release channel of the second heat exchanger are used for heat exchange. The thermal storage system further includes: a second hot storage tank, a second cold storage tank, a third heat exchanger, and a fourth heat exchanger. The inlet end of the heat absorption channel of the third heat exchanger is connected to the outlet end of the second cold storage tank, and the outlet end of the heat absorption channel of the third heat exchanger is connected to the inlet end of the second hot storage tank. The heat release channel of the third heat exchanger is connected in series to the outlet end of the heat release channel of the second heat exchanger, and the heat exchange is used for heat exchange between the heat absorption channel and the heat release channel of the third heat exchanger. The inlet end of the heat release channel of the fourth heat exchanger is connected to the outlet end of the second hot storage tank, and the outlet end of the heat release channel of the fourth heat exchanger is connected to the inlet end of the second cold storage tank. The heat absorption channel of the fourth heat exchanger is connected in series to the inlet end of the heat absorption channel of the steam power generation system, and the heat exchange is used for heat exchange between the heat absorption channel and the heat release channel of the fourth heat exchanger.

2. The coal gasification combined cycle unit according to claim 1, characterized in that, The thermal storage system also includes: The fifth heat exchanger has its heat absorption channel inlet end connected to the liquid outlet end of the first cold storage tank, its heat absorption channel outlet end connected to the liquid inlet end of the first hot storage tank, and its heat release channel connected in series to the gas outlet end of the heat release channel of the first heat exchanger. The heat absorption channel and the heat release channel of the fifth heat exchanger are used for heat exchange.

3. The coal gasification combined cycle unit according to claim 1, characterized in that, The coal gasification combined cycle unit also includes: An electrochemical energy storage system, wherein the power supply terminal of the electrochemical energy storage system is connected to the power supply terminal of the gas-fired power generation system and the power supply terminal of the steam power generation system, respectively; The power supply terminals of the electrochemical energy storage system, the gas-fired power generation system, and the steam power generation system are respectively connected to the power supply terminals of the power grid.

4. The coal gasification combined cycle unit according to claim 1, characterized in that, The coal gasification system includes: Oxygen storage tanks, coal gasification furnaces, condensation and purification devices, and combustible gas storage tanks; The outlet of the oxygen storage tank is connected to the inlet of the coal gasification furnace, the outlet of the coal gasification furnace is connected to the inlet of the condensation and purification device, the outlet of the condensation and purification device is connected to the inlet of the combustible gas storage tank, and the outlet of the combustible gas storage tank is connected to the inlet of the gas-fired power generation system. The thermal storage system is located between the gas outlet path of the coal gasifier and the liquid inlet path of the steam power generation system. The thermal storage system is used to heat the liquid inlet of the steam power generation system into steam using the waste heat from the gas outlet of the coal gasifier.

5. The coal gasification combined cycle unit according to claim 4, characterized in that, The coal gasification system also includes: An air separator and a nitrogen storage tank are provided, wherein the nitrogen outlet of the air separator is connected to the inlet of the nitrogen storage tank, and the oxygen outlet of the air separator is connected to the inlet of the oxygen storage tank.

6. The coal gasification combined cycle unit according to claim 1, characterized in that, The gas-fired power generation system includes: Compressor, combustion chamber, gas turbine, and gas generator; The combustion chamber's inlet is connected to both the gas outlet of the coal gasification system and the gas compressor; the combustion chamber's outlet is connected to the gas turbine's inlet; and the gas turbine's power output is connected to both the gas compressor's power input and the gas generator's power input.

7. The coal gasification combined cycle unit according to claim 1, characterized in that, The steam power generation system includes: A steam generator, wherein the heat storage system is disposed between the gas outlet path of the coal gasification system and the heat release channel of the steam generator, and between the gas outlet path of the gas power generation system and the heat absorption channel of the steam generator, wherein the heat storage system is used to heat the liquid inlet of the heat absorption channel of the steam generator into steam by utilizing the waste heat from the gas outlet of the coal gasification system and the waste heat from the gas outlet of the gas power generation system. A steam turbine, wherein the steam inlet of the steam turbine is connected to the steam outlet of the heat absorption channel of the steam generator.

8. The coal gasification combined cycle unit according to claim 7, characterized in that, The steam power generation system also includes: The condenser has its steam inlet connected to the steam outlet of the steam turbine, and its liquid outlet connected to the liquid inlet of the heat absorption channel of the steam generator.

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