Comprehensive energy supply system based on gas engine residual smoke hydrogen energy storage system

Abstract

The invention discloses a comprehensive energy supply system based on a gas engine residual smoke hydrogen energy storage system, and relates to the field of energy supply. The total smoke exhaust amount of a gas engine is calculated, and the first smoke amount needed by a cold and hot water unit is calculated; when the total smoke exhaust amount of the gas engine is smaller than or equal to the first smoke amount needed by the water chiller-heater unit, all smoke is guided into the lithium bromide absorption water chiller-heater unit; if the first smoke amount is larger than the first smoke amount needed by the lithium bromide absorption type cold and hot water unit, the remaining smoke is guided into a remaining smoke boiler to be used for generating water vapor; determining the amount of second flue gas discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler, calculating the total smoke inlet amount of the residual smoke boiler, calculating the required natural gas raw material amount according to the water vapor mass flow and the total carbon flow in the natural gas, and introducing the natural gas into the hydrogenation reaction combustion furnace according to the natural gas raw material amount. The natural gas reforming hydrogen production equipment, the waste smoke boiler, the gas engine and the like are integrated for cold, heat and electricity triple co-generation and can be directly applied to building energy supply, and effective cyclic utilization is formed.

Description

Technical Field

[0001] The present invention relates to the technical field of energy supply, and in particular to a comprehensive energy supply system based on a gas engine residual smoke hydrogen energy storage system. Background Art

[0002] As a clean, carbon-free new energy source, hydrogen energy will play an increasingly important role in the construction sector in the foreseeable future. At present, conventional natural gas reforming hydrogen production equipment is generally large and is mostly used in industry. As for how to apply it to the construction sector, there is no perfect and feasible solution.

[0003] At the same time, there is no effective recycling mechanism for the waste heat from flue gas generated during gas turbine power generation, which not only causes secondary energy waste, but also increases the system's implicit carbon emissions. How to effectively combine gas turbine power generation, waste heat recovery, hydrogen energy storage and buildings will become a problem that needs to be solved. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a comprehensive energy supply system based on a gas engine waste smoke hydrogen energy storage system that is effectively combined with a building energy supply system. The system integrates the trigeneration of cooling, heating and electricity such as natural gas reforming hydrogen production equipment, waste smoke boilers and gas engines and can be directly applied to building energy supply, thereby forming an effective recycling utilization.

[0005] The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system includes a gas engine, reforming hydrogen production equipment and a lithium bromide absorption hot and cold water unit, among which:

[0006] The input end of the lithium bromide absorption cold and hot water unit is connected to the high-temperature flue gas channel of the gas engine, and its output end is connected to the cold and hot water pipeline for building air conditioning;

[0007] The reforming hydrogen production equipment includes a residual smoke boiler, a hydrogenation reaction combustion furnace and an intermediate transformer. The first input end of the residual smoke boiler is connected to the high-temperature flue gas pipeline of the gas engine, and the second input end of the residual smoke boiler is connected to the flue gas channel of the hydrogenation reaction combustion furnace; the intermediate transformer is connected to the rear end of the hydrogenation reaction combustion furnace; the terminal hydrogen output end of the reforming hydrogen production equipment is connected to the hydrogen fuel cell;

[0008] Calculate the total exhaust volume of the gas engine per unit time, and calculate the first flue gas volume required by the lithium bromide absorption cold and hot water unit per unit time;

[0009] When the total exhaust volume of the gas engine is less than or equal to the first flue gas volume required by the lithium bromide absorption cold and hot water unit, all the flue gas is introduced into the lithium bromide absorption cold and hot water unit;

[0010] When the total amount of flue gas exhaust from the gas engine is greater than the first flue gas amount required by the lithium bromide absorption cold and hot water unit, a sufficient amount of flue gas is introduced into the lithium bromide absorption cold and hot water unit according to the flue gas amount required by the lithium bromide absorption cold and hot water unit, and the remaining flue gas is introduced into the residual smoke boiler for generating water vapor; the second flue gas amount discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler is determined according to the working state of the hydrogenation reaction combustion furnace; the total flue gas intake amount of the residual smoke boiler is calculated according to the total exhaust amount, the first flue gas amount and the second flue gas amount;

[0011] The amount of water vapor generated is calculated based on the total smoke intake, the amount of natural gas raw material required is calculated based on the water vapor, and the natural gas is introduced into the hydrogenation reaction combustion furnace based on the amount of natural gas raw material.

[0012] The beneficial effects include: 1) Compared with the existing waste heat recovery and utilization hydrogen production device, some existing devices only achieve water vapor production through waste heat recovery technology, and then combine with natural gas for mixed reaction conversion to obtain hydrogen. The purpose of the present invention is to effectively utilize the waste heat and waste smoke of the gas engine cooling, heating and power trigeneration system to organically combine with the natural gas reforming hydrogen production method. When the building's cooling and heating load demand is insufficient in the transition season, the gas engine's sufficient waste smoke can be effectively recovered through the waste smoke boiler to produce high-temperature water vapor for natural gas reforming hydrogen production for hydrogenation reaction. On the one hand, the cost of hydrogen production by conventional methods of natural gas reforming hydrogen production is effectively reduced, mainly by greatly saving the cost of water vapor fuel for hydrogen production. On the other hand, it also effectively avoids the waste of gas engine waste smoke and waste heat when the building's cooling and heating load demand is small. In terms of waste smoke utilization, in addition to utilizing the high-temperature waste smoke of the gas engine, the present invention also effectively integrates and utilizes the flue gas in the hydrogenation reaction combustion furnace, further saving the heating raw material cost of hydrogen production, which can save 30% to 50% of the raw material cost. In addition, when the energy supply device and method are applied in actual buildings, the method of the present application can be used to accurately calculate and predict the hourly hydrogen production and the required amount of natural gas raw materials according to the hourly cooling, heating and electricity loads of different buildings.

[0013] 2) In the case that natural gas reforming hydrogen production can be modularized in small scale, the system proposed in this application only needs to combine the modular miniaturized natural gas reforming hydrogen production equipment, exhaust gas boiler, and gas engine cooling, heating and power trigeneration directly on the building site, and can be directly used in the building, which has practical engineering application value.

[0014] This application selects a hydrogen fuel cell that can realize the effective use of hydrogen nearby. The application of hydrogen fuel cells in this system can directly power the building, and secondly, it can effectively recover the waste heat of the hydrogen fuel cell and generate heat energy for the building's hot water storage tank. The innovative design of this system takes into account that the economic efficiency of the generated hydrogen is poor if it is transported over long distances. Only when the generated hydrogen is directly used nearby can it generate higher economic benefits. The present invention realizes the integration of cold, heat and electricity trigeneration of reforming hydrogen production equipment, residual smoke boilers and gas engines through improvements in structure and method to provide comprehensive energy supply to the entire building or building park.

[0015] As a preferred implementation, a method for calculating the required amount of natural gas feedstock based on the amount of water vapor and the total carbon flow in the natural gas includes:

[0016] Calculate the total carbon flow in natural gas based on the proportion of each component gas in natural gas;

[0017] Determine the water-carbon ratio of natural gas for hydrogen production, and calculate the natural gas volume flow rate based on the water-carbon ratio calculation formula combined with the total carbon flow rate in the natural gas and the water vapor mass flow rate;

[0018] According to the chemical reaction formula of natural gas to hydrogen production, the amount of natural gas raw material that needs to be imported is calculated in combination with the total carbon flow in the natural gas and the mass flow of water vapor generated by the residual smoke boiler.

[0019] As a preferred implementation, the method for calculating the total amount of smoke exhaust per unit time of the gas engine comprises the following steps:

[0020] Determine the hourly electricity load demand of the building, and calculate the actual hourly power generation of the gas engine based on the building's green power generation, hydrogen fuel cell power generation, and the rated power generation of the gas engine at full load, as shown in the following formula;

[0021]

[0022] In the formula is the power generation of the gas engine, is the rated power generation of the gas engine at full load, is the hourly electricity load of the building, Green electricity generation, is the electricity generated by the hydrogen fuel cell;

[0023] Among them, green electricity includes solar or wind power connected to the building;

[0024] The total exhaust volume of the gas engine generated by the gas engine during power generation is then determined based on the hourly power generation of the gas engine.

[0025] As a preferred implementation, the total smoke intake of the residual smoke boiler is calculated based on the total smoke exhaust volume, the first smoke volume and the second smoke volume. (kg / h) method, as shown in the following formula:

[0026]

[0027] In the formula (kg / h) is the total exhaust volume of the gas engine per unit time, (kg / h) is the first flue gas volume required for cooling or heating of the lithium bromide absorption cold and hot water unit. (kg / h) is the second flue gas volume discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler.

[0028] As a preferred implementation, the amount of water vapor generated is calculated based on the total smoke intake, which is achieved by the following formula:

[0029]

[0030] —Mass flow rate of water vapor generated by the residual smoke boiler (kg / h);

[0031] —Recoverable flue gas waste heat from flue gas boiler (kJ / h);

[0032] — enthalpy of water vapor during hydrogen reaction (kJ / kg);

[0033] —Enthalpy of industrial water at room temperature (kJ / kg);

[0034] —mass specific heat capacity of flue gas (kJ / (kg·℃));

[0035] —The amount of flue gas entering the residual smoke boiler (kg / h);

[0036] —Average temperature of flue gas at the inlet of residual smoke boiler (℃);

[0037] —Average flue gas temperature at the outlet of residual smoke boiler (℃);

[0038] —Flue gas heat loss coefficient.

[0039] As a preferred implementation, the amount of natural gas raw material to be introduced is calculated according to the chemical reaction formula for hydrogen production from natural gas, combined with the total carbon flow in the natural gas and the mass flow of water vapor generated by the residual smoke boiler, and is specifically calculated by the following formula:

[0040] The total carbon flow in natural gas is calculated as follows:

[0041] ,

[0042] In the formula is the total carbon flow in natural gas, is the volume percentage of methane in natural gas, is the volume percentage of ethane, is the volume percentage of propane, is the volume percentage of butane;

[0043] Determine the water-carbon ratio of natural gas hydrogen production, and calculate the natural gas volume flow rate based on the water-carbon ratio calculation formula combined with the total carbon flow rate in the natural gas and the water vapor volume flow rate as follows:

[0044] ,

[0045] In the formula is the water-carbon ratio, determined as a constant based on experience, is the volume flow rate of natural gas (Nm 3 / h), is the water vapor volume flow rate (Nm 3 / h).

[0046] As a preferred implementation, the reforming hydrogen production equipment also includes a natural gas pipeline, a desulfurizer, a desulfurized natural gas and water vapor mixer, a gas-liquid separator, a hydrogen purification device and an exhaust gas collector, wherein:

[0047] The first input end of the desulfurized natural gas and water vapor mixer is connected to the water vapor output end of the residual smoke boiler, and the output end of the desulfurized natural gas and water vapor mixer is connected to the hydrogenation reaction combustion furnace;

[0048] The first output end of the natural gas pipeline is connected to the desulfurizer, and the output end of the desulfurizer is connected to the second input end of the desulfurized natural gas and water vapor mixer;

[0049] The hydrogenation reaction combustion furnace includes a high-temperature reaction furnace and a flue gas channel, the input end of the high-temperature reaction furnace is connected to the output end of the desulfurized natural gas and water vapor mixer, and the flue gas output end of the flue gas channel is connected to the residual smoke boiler; the output end of the high-temperature reaction furnace is connected to the input end of the medium transformer, the output end of the medium transformer is connected to the input end of the gas-liquid separator, and the output end of the gas-liquid separator is connected to the input end of the hydrogen purification device;

[0050] The first output end of the hydrogen purification device is connected to the hydrogen power generation device, the second output end of the hydrogen purification device is connected to the exhaust gas collector, and the output end of the exhaust gas collector is connected to the natural gas pipeline.

[0051] As a preferred implementation, it also includes a hydrogen compressor and a natural gas compressor.

[0052] The input end of the hydrogen compressor is connected to the hydrogen purification device, and the output end of the hydrogen compressor is connected to the hydrogen power generation device;

[0053] The input end of the natural gas compressor is connected to the natural gas pipeline, and the output end of the natural gas compressor is connected to the input end of the desulfurizer.

[0054] As a preferred implementation, it also includes a first heat exchanger installed in the connecting pipeline between the high-temperature reaction furnace and the desulfurized natural gas and water vapor mixer;

[0055] A second heat exchanger, comprising a first cooling channel and a second cooling channel, wherein the first cooling channel is installed in a connecting pipe between the desulfurizer and the high-temperature reaction furnace, and the second cooling channel is installed in a connecting pipe between the compressor and the medium-temperature transformer;

[0056] The third heat exchanger is installed in the connecting pipeline between the gas-liquid separator and the intermediate transformer.

[0057] As a preferred implementation, it also includes a hot water storage tank, one end of the third heat exchanger is the cooling water input end, and the other end is output to one input end of the hot water storage tank, and the other input end of the hot water storage tank is connected to the heat output end of the hydrogen power generation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 This is the overall structural diagram of the comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system;

[0060] Figure 2 It is the flow chart for calculating total carbon flow and hydrogen production from natural gas;

[0061] Figure 3 It is a flow chart for calculating the amount of natural gas raw materials and the amount of hydrogen produced. DETAILED DESCRIPTION

[0062] The present invention is further described in detail below in conjunction with the embodiments, which are explanations of the present invention and are not limited to the following embodiments. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention.

[0063] Comprehensive energy supply system based on gas engine residual smoke hydrogen energy storage system, reference Figure 1, including gas engines, reforming hydrogen production equipment and lithium bromide absorption hot and cold water units, among which,

[0064] The input end of the lithium bromide absorption cold and hot water unit is connected to the high-temperature flue gas channel of the gas engine, and its output end is connected to the cold and hot water pipeline for building air conditioning;

[0065] The reforming hydrogen production equipment includes a residual smoke boiler, a hydrogenation reaction combustion furnace and an intermediate transformer. The first input end of the residual smoke boiler is connected to the high-temperature flue gas pipeline of the gas engine, and the second input end of the residual smoke boiler is connected to the flue gas channel of the hydrogenation reaction combustion furnace; the intermediate transformer is connected to the rear end of the hydrogenation reaction combustion furnace; the terminal hydrogen output end of the reforming hydrogen production equipment is connected to the hydrogen fuel cell;

[0066] Calculate the total exhaust volume of the gas engine per unit time, and calculate the first flue gas volume required by the lithium bromide absorption cold and hot water unit per unit time;

[0067] When the total exhaust volume of the gas engine is less than or equal to the first flue gas volume required by the lithium bromide absorption cold and hot water unit, all the flue gas is introduced into the lithium bromide absorption cold and hot water unit;

[0068] When the total amount of flue gas exhaust from the gas engine is greater than the first flue gas amount required by the lithium bromide absorption cold and hot water unit, a sufficient amount of flue gas is introduced into the lithium bromide absorption cold and hot water unit according to the flue gas amount required by the lithium bromide absorption cold and hot water unit, and the remaining flue gas is introduced into the residual smoke boiler for generating water vapor; the second flue gas amount discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler is determined according to the working state of the hydrogenation reaction combustion furnace; the total flue gas intake amount of the residual smoke boiler is calculated according to the total exhaust amount, the first flue gas amount and the second flue gas amount;

[0069] The amount of water vapor generated is calculated based on the total smoke intake, the amount of hydrogen produced is calculated based on the water vapor, the amount of natural gas raw material required is calculated based on the hydrogen produced, and natural gas is introduced into the hydrogenation reaction combustion furnace based on the amount of natural gas raw material.

[0070] Combined with reference Figure 2 and Figure 3 Understand the following disclosure.

[0071] (I) Calculate the total amount of smoke exhaust per unit time using the following formula:

[0072] Gas turbines can use natural gas to generate electricity and high-temperature flue gas at the same time. The calculation method of power generation and heat is as follows:

[0073] (1)

[0074] (2)

[0075] In the formula (kW) is the power generation of the gas engine, (m 3 / h) is the natural gas consumption of the gas engine, (MJ / m 3 ) is the calorific value of natural gas, is the power generation efficiency of the gas engine, (kW) is the heat recovered by the high-temperature residual smoke of the gas engine through the residual smoke boiler. is the heat loss rate of the gas engine.

[0076] Specifically, the method for calculating the total amount of smoke exhaust per unit time of the gas engine is to determine the hourly electricity load demand of the building, calculate the actual hourly power generation of the gas engine based on the building's green power generation, hydrogen fuel cell power generation and the rated power generation of the gas engine at full load, and then determine the total amount of smoke generated by the gas engine accompanying power generation based on the hourly power generation of the gas engine. (kg / h).

[0077] Green electricity includes solar or wind power connected to buildings.

[0078] The calculation method of the hourly power generation of the gas engine is as follows:

[0079] First, the power generation capacity P of the gas engine engine (kwh / h) According to the performance of the equipment and the power supply configuration method set in this study, the load rate of the gas engine must be maintained at 50% to 100% for safe operation. After the gas engine supplies power to the building, it is then supplied by solar and wind power. If the power is insufficient, it is supplied by commercial power. Therefore, the power generation of the gas engine P engine (kWh / h) can be determined by the following formula:

[0080] (3)

[0081] In the formula is the power generation of the gas engine, is the rated power generation of the gas engine at full load, is the hourly electricity load of the building, Green electricity generation, is the power generation of the hydrogen fuel cell. For the safe operation of the gas engine, its operating load generally needs to be maintained above 50%. When the power generation of the gas engine is known, the amount of natural gas consumed by the gas engine can be calculated using the above formula (1).

[0082] Specifically, green electricity takes solar power generation as an example, and renewable energy solar power generation is given priority in building power supply. Since the load rate of the gas engine needs to be maintained above 50%, When the power generation of the gas engine is ;when When the power generation of the gas engine is ;when When the power generation of the gas engine is the total rated power generation under full load operation .when When the total power generation of the gas engine, solar power generation and hydrogen fuel cell power generation cannot cover the power load demand of the building, the insufficient power is supplemented by the commercial power EC. If there is surplus power, the surplus power is used to provide the stable power load required by the hydrogen or natural gas compressor to compress the gas. Among them, the power generation of solar energy and hydrogen fuel cells can be calculated by the corresponding formula (5) and formula (6), and the building hourly power load It can be obtained by combining building history data and survey data.

[0083] The method for calculating the total exhaust volume of a gas engine based on the power generation of the gas engine is as follows: According to the performance data analysis of the gas engine equipment provided by the equipment manufacturer, the exhaust volume of the gas engine The calculation of (kg / h) is shown in formula (4).

[0084] (4)

[0085] In the formula (kg / h) is the total exhaust volume of the gas engine, E is the gas turbine load rate, which is the ratio of the actual power generation of the gas turbine to the rated full-load power generation. TGE (kW) is the rated full load power generation.

[0086] Regarding green electricity, this application takes solar panels as an example, and the solar power generation calculation formula is as follows:

[0087] (5)

[0088] In the formula is the power generation of solar panels (kW), is the solar radiation per unit area (kW / m 2 ), S is the solar panel area (m 2 ), is the conversion efficiency of the component (generally 16-18%, 17% in this application); is the overall efficiency of the system (generally 75% to 85%, 80% for this application). In addition, (kW / m 2 ) data are derived from climate data obtained through surveys.

[0089] The calculation of the power generation of hydrogen fuel cells is as follows:

[0090] (6)

[0091] (7)

[0092] In the formula (W) is the power generation of the hydrogen fuel cell, (Nm 3 / h) is the amount of hydrogen entering the hydrogen fuel cell for power generation, (MJ / m 3 ) is the calorific value of hydrogen, The power generation efficiency of hydrogen fuel cells, is the heat recovery efficiency of hydrogen fuel cells.

[0093] According to the total exhaust volume of gas engine (kg / h), first flue gas volume (kg / h) and the second flue gas volume (kg / h) Calculate the total smoke intake of the residual smoke boiler (kg / h), calculated by formula (8):

[0094] (8)

[0095] In the formula (kg / h) is the total exhaust volume of the gas engine, (kg / h) is the first flue gas volume required for cooling or heating of the lithium bromide absorption cold and hot water unit. (kg / h) is the second flue gas volume discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler.

[0096] When the building has a cooling and heating load demand, a portion of the gas engine flue gas enters the lithium bromide absorption hot and cold water unit to produce hot and cold water for building air conditioning, that is, the first flue gas volume (kg / h), remaining gas engine flue gas volume (kg / h) all enter the exhaust gas boiler to generate water vapor for hydrogen production.

[0097] The total amount of smoke entering the residual smoke boiler to produce water vapor (kg / h) In addition to the gas engine, there is also the second flue gas volume discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler (kg / h). When the flue gas generated by the gas engine is only enough to meet the cooling and heating load requirements of the building air conditioning, the amount of flue gas entering the residual smoke boiler to generate water vapor for hydrogen production is only the flue gas from the hydrogenation reactor. (kg / h); when , it means that the flue gas generated by the gas engine is used to provide the cooling and heating load requirements of the building, and there is also a surplus. At this time, the total flue gas intake of the residual smoke boiler flue is (kg / h) is If the hydrogenation burner is currently running, the total smoke intake includes the second smoke volume If the hydrogenation burner is not running, the second flue gas volume is 0.

[0098] More specifically, the first flue gas volume required to produce hot and cold water for building air conditioning by a lithium bromide absorption hot and cold water unit can be calculated using the following formula (9).

[0099] (9)

[0100] in (kg / h) is the amount of flue gas required for cooling or heating by the lithium bromide absorption chiller. (kJ / kg) is the flue gas enthalpy entering the lithium bromide absorption hot and cold water unit. (kJ / kg) is the flue gas enthalpy leaving the lithium bromide absorption chiller / hot water unit. It is the coefficient of performance (COP) of the lithium bromide absorption chiller and hot water unit. This value is a constant. (kWh / h) is the hourly cooling load or heating load of different types of buildings. Through investigation, the hourly cooling load or heating load value of different types of buildings can be obtained, and its value is the product of the daily cooling or heating load value and the hourly load percentage. (kJ / kg) and (kJ / kg) is calculated using the following formula (10).

[0101] (10)

[0102] In the formula (kJ / kg) is the flue gas enthalpy, (℃) is the flue gas temperature. This formula is summarized by the applicant based on the residual flue gas enthalpy table of gas engines. and It can be determined by substituting the flue gas temperature at the time of entry and the flue gas temperature at the time of exit into formula (10).

[0103] (ii) Calculate the mass flow rate of water vapor generated based on the total smoke intake, calculate the required amount of natural gas feedstock based on the mass flow rate of water vapor and the total carbon flow rate in the natural gas, and introduce natural gas into the hydrogenation reaction combustion furnace based on the amount of natural gas feedstock.

[0104] When the flue gas volume entering the residual smoke boiler (kg / h) is determined, the amount of water vapor for hydrogen production generated by the residual smoke boiler can be determined according to formula (11): (kg / h),

[0105] (11)

[0106] —The mass flow rate of water vapor generated by the residual smoke boiler (kg / h);

[0107] —Recoverable flue gas waste heat from flue gas boiler (kJ / h);

[0108] — enthalpy of water vapor during hydrogen reaction (kJ / kg);

[0109] —Enthalpy of industrial water at room temperature (kJ / kg); For example, the room temperature can be set to 20°C;

[0110] — specific heat capacity of flue gas mass (kJ / (kg·℃)); for example, 1.15 kJ / (kg·℃) is used in this embodiment;

[0111] —The amount of flue gas entering the residual smoke boiler (kg / h);

[0112] —Average temperature of flue gas at the inlet of residual smoke boiler (℃);

[0113] —Average flue gas temperature at the outlet of the residual smoke boiler (°C); generally 150°C;

[0114] —Flue gas heat loss coefficient; usually taken as 0.9.

[0115] Among them, according to the actual performance of the equipment, the exhaust temperature of the flue gas boiler should generally not be lower than 150°C, otherwise the tail heating surface will be corroded. The following formula (12):

[0116] (12)

[0117] In the formula Indicates the waste heat of flue gas recovered by the flue gas boiler (kJ / h). is the mass specific heat capacity of flue gas (kJ / (kg·℃)), and its value is 1.15 kJ / (kg·℃), is the flue gas mass flow rate entering the residual smoke boiler (kg / h), is the average temperature of flue gas at the inlet of residual smoke boiler (℃), is the average flue gas temperature at the outlet of the residual smoke boiler (℃), which is generally 150℃. Considering that the exhaust temperature of the residual smoke boiler should generally not be lower than 150℃, otherwise the tail heating surface will be corroded. is the flue gas heat loss coefficient, usually taken as 0.9.

[0118] Then, the corresponding amount of water vapor for hydrogen production is determined by formula (13): (kg / h) Amount of hydrogen that can be produced (Nm 3 / h), as follows:

[0119] (13)

[0120] In the formula (Nm 3 / h) is the actual hydrogen production; (kg / h) is the mass flow rate of water vapor generated by the residual smoke boiler when the residual smoke is recovered and used to heat water. is the density of water vapor (kg / Nm 3 ). It should be noted that in this application, the hydrogen production is determined by the waste heat recovered by the residual smoke boiler, that is, the hydrogen is determined by heat. When there is no residual smoke from the gas engine entering the residual smoke boiler to produce the water vapor required for the hydrogenation reaction, the hydrogen production is also correspondingly 0. Only when there is residual heat from the residual smoke to produce the water vapor required for the hydrogenation reaction, the hydrogen production will proceed, otherwise the hydrogen production will stop. This hydrogen production method can be used to calculate the power generation of hydrogen fuel cells.

[0121] The main reactions in the hydrogen production process are as follows:

[0122] C m H n + mH2O→mCO + (n+2m) / 2H2 (14)

[0123] ZnO + H2S → ZnS + H2O (15)

[0124] CO + H2O → CO2 + H2 (16)

[0125] The calculation process of hydrogen production and carbon flow rate of gas engine residual smoke is as follows: Figure 2 As shown. Natural gas mainly includes four gases, each of which can produce hydrogen. In the first stage, the reaction of the four gases follows the following chemical formula: m H n + mH2O→mCO+(n+2m) / 2H2, which is an endothermic reaction. In the second stage of the intermediate reaction, the reaction follows the following chemical formula: CO+H2O→CO2+H2, which is an exothermic reaction. In summary, the chemical reaction of each gas in the natural gas in the two stages is: C mH n +2mH2O→mCO2+(4m+n) / 2H2, where m can be 1, 2, 3, or 4, and n can be 4, 6, 8, or 10, representing four different gases in natural gas. The main component of natural gas is methane (CH4), accounting for 85% of the volume, followed by ethane (C2H6) accounting for 9%, propane (C3H8) accounting for 3%, and butane (C4H 10 ) accounts for 1%. In addition, it also contains 2% nitrogen (N2) and trace amounts of hydrogen sulfide (H2S).

[0126] Based on the composition of natural gas, the calculation formula of carbon atoms in natural gas obtained in this application is shown in formula (17):

[0127] (17)

[0128] In the formula is the total carbon content of natural gas, is the volume percentage of methane (CH4) in natural gas, is the volume percentage of ethane (C2H6), is the volume percentage of propane (C3H8), Butane (C4H 10 ) volume percentage.

[0129] Multiply the number of carbon atoms in each gas by the corresponding volume ratio to get the result of the carbon flow rate per unit of natural gas. CH4 has 1 carbon atom, C2H6 has 2 carbon atoms, C3H8 has 3 carbon atoms, and C4H 10 There are 4 carbon atoms in , so the final calculated carbon flow rate per unit of natural gas is 1.16. If there is 1 unit volume of natural gas, then it will contain 0.85 unit volume of methane, and the reaction requires 2×0.85 unit volume of water vapor, corresponding to 0.85 unit volume of CO2 and 4×0.85 unit volume of H2. The calculation process of hydrogenation reaction of other gases is also the same Figure 2 As shown. One unit volume of natural gas requires 2×0.85 + 4×0.09 + 6×0.03 + 8×0.01 = 2.32 units of water vapor to react, which in turn produces 4×0.85 + 7×0.09 + 10×0.03 + 13×0.01 = 4.46 units of hydrogen. Therefore, 40m 3 / h of natural gas will be able to output 40×4.46=178.4m 3 / h of H2.

[0130] According to formula (17), the total number of carbon atoms in natural gas is 1.16. The carbon atom content in natural gas is directly related to the amount of water vapor required for the hydrogenation reaction, while the waste heat of flue gas entering the flue gas boiler directly determines the amount of water vapor produced.

[0131] When calculating the amount of water vapor required for hydrogen production by hydrogenation, it is necessary to determine the total carbon atom content in natural gas to calculate the water-carbon ratio. Under normal production conditions, controlling the water-carbon ratio of water and natural gas is the key to hydrogen production from natural gas. The water-carbon ratio for hydrogen production is generally 3 to 5, and the normal water-carbon ratio is 3.5. If the deviation from this ratio is too large, it may lead to waste of water vapor. If the value is too small, it will cause carbon deposition on the hydrogenation reaction catalyst and deactivate it. According to previous studies, the water-carbon ratio of this application is set to 3.5. The water-carbon ratio calculation formula is formula (18), and the carbon flow rate is determined by the superposition of each carbon atom-containing gas in the natural gas:

[0132] (18)

[0133] In the formula is the water-carbon ratio, which is 3.5 in this application, V natural is the volume flow rate of natural gas (Nm 3 / h), V steam is the water vapor volume flow rate (Nm 3 / h), is the total volume flow rate of carbon in natural gas (Nm 3 / h), 1.16 is the calculated total number of carbon atoms in natural gas.

[0134] From the above formula (17), it can be seen that the total number of carbon atoms in natural gas is 1.16. According to the above formula, the required natural gas volume flow rate can be calculated by the water vapor volume flow rate.

[0135] For example, if 40Nm is used 3 / h natural gas is used as the raw material for hydrogen production. The carbon flow rate of natural gas is the product of the volume flow rate and the total number of carbon atoms, which is 46.4 Nm 3 / h. Since the water-carbon ratio is generally selected to be 3.5, 40Nm 3 The steam flow rate required for the hydrogenation reaction of natural gas is 162.4 Nm / h. 3 / h.

[0136] The reforming hydrogen production equipment also includes a natural gas pipeline, a desulfurizer, a desulfurized natural gas and water vapor mixer, a gas-liquid separator, a hydrogen purification device and an exhaust gas collector. Figure 1 ,in,

[0137] The first input end of the desulfurized natural gas and water vapor mixer is connected to the water vapor output end of the residual smoke boiler, and the output end of the desulfurized natural gas and water vapor mixer is connected to the hydrogenation reaction combustion furnace;

[0138] The first output end of the natural gas pipeline is connected to the desulfurizer, and the output end of the desulfurizer is connected to the second input end of the desulfurized natural gas and water vapor mixer;

[0139] The hydrogenation reaction combustion furnace includes a high-temperature reaction furnace and a flue gas channel, the input end of the high-temperature reaction furnace is connected to the output end of the desulfurized natural gas and water vapor mixer, and the flue gas output end of the flue gas channel is connected to the residual smoke boiler; the output end of the high-temperature reaction furnace is connected to the input end of the medium transformer, the output end of the medium transformer is connected to the input end of the gas-liquid separator, and the output end of the gas-liquid separator is connected to the input end of the hydrogen purification device;

[0140] The first output end of the hydrogen purification device is connected to the hydrogen power generation device, the second output end of the hydrogen purification device is connected to the exhaust gas collector, and the output end of the exhaust gas collector is connected to the natural gas pipeline.

[0141] The above structure innovatively mixes the combustible gas remaining after hydrogen purification in natural gas reforming hydrogen production into the building gas supply pipeline, further effectively combining the residual smoke hydrogen storage method in this application with the building energy supply.

[0142] The preferred structure also includes a hydrogen compressor and a natural gas compressor.

[0143] The input end of the hydrogen compressor is connected to the hydrogen purification device, and the output end of the hydrogen compressor is connected to the hydrogen power generation device;

[0144] The input end of the natural gas compressor is connected to the natural gas pipeline, and the output end of the natural gas compressor is connected to the input end of the desulfurizer.

[0145] The preferred structure further includes a first heat exchanger installed in the connecting pipeline between the high-temperature reaction furnace and the desulfurized natural gas and water vapor mixer;

[0146] A second heat exchanger, comprising a first cooling channel and a second cooling channel, wherein the first cooling channel is installed in a connecting pipe between the desulfurizer and the high-temperature reaction furnace, and the second cooling channel is installed in a connecting pipe between the compressor and the medium-temperature transformer;

[0147] The third heat exchanger is installed in the connecting pipeline between the gas-liquid separator and the intermediate transformer.

[0148] It also includes a heat storage tank. One end of the third heat exchanger is a cooling water input end, and the other end is output to one input end of the heat storage tank. The other input end of the heat storage tank is connected to the heat output end of the hydrogen power generation device.

[0149] The above is the specific operation mode of the comprehensive energy supply system:

[0150] Gas engines use natural gas as raw material to generate electricity, and while generating electricity, they produce high-temperature flue gas, the temperature of which can generally reach around 368 to 469°C.

[0151] When the building has a stable demand for cooling and heating loads in summer and winter, the flue gas of the gas engine can be used to generate chilled water / hot water for building air conditioning through the lithium bromide absorption hot and cold water unit to provide the building's cooling and heating load needs. When the building has no stable demand for cooling and heating loads during the transition season, the flue gas of the gas engine can be used to generate high-temperature water vapor required for the hydrogen production reaction through the waste smoke boiler to avoid the waste of flue gas waste heat. The high-temperature water vapor generated by the waste heat boiler is mixed with the natural gas desulfurized by the desulfurizer in the natural gas and water vapor mixer, and then enters the high-temperature reactor placed in the combustion furnace for hydrogenation reaction. The reason why natural gas needs to be desulfurized is that the sulfide contained in it will make the catalyst of the hydrogenation reaction ineffective. For this reason, the natural gas in the natural gas pipeline needs to be preheated by the heat exchanger after being compressed by the compressor before entering the desulfurizer for desulfurization.

[0152] The first heat exchanger is built into the inner wall of the flue gas channel in the combustion furnace. The desulfurized natural gas and water vapor mixture first flows through the first heat exchanger in the combustion furnace for preheating, so as to accelerate the hydrogenation reaction speed and the required reaction temperature. The hydrogenation reaction temperature in the high-temperature reactor is about 735°C, so the natural gas in the natural gas pipeline is needed as a heating fuel for combustion and temperature increase. The natural gas in the natural gas pipeline burns with air oxygen to heat the high-temperature reactor. At the same time, the flue gas generated by the combustion flows through the flue gas channel in the combustion furnace and finally enters the residual smoke boiler to generate high-temperature water vapor for hydrogen production.

[0153] The main component of natural gas is CH4, and the main chemical equation of its hydrogenation reaction is CH4 + H2O→CO + 3H2. It is an endothermic process with a reaction temperature of about 735°C. After the hydrogenation reaction, the mixed gas flows through the second heat exchanger to heat the natural gas to be desulfurized after coming out of the high-temperature reactor. Because the desulfurization reaction temperature is between 290 and 350°C, the natural gas to be desulfurized needs to be preheated first. The mixed gas entering the intermediate converter needs to be cooled down because the intermediate converter reaction is an exothermic reaction. The reaction temperature only needs to be around 200 to 300°C. The main chemical equation of the reaction is CO + H2O→CO2+ H2. After the intermediate converter reaction, the mixed gas flows through the third heat exchanger from the intermediate converter, and after being cooled by cooling water, it is cooled down and enters the gas-liquid separator for gas-liquid separation. After the cooling water is heated up by the heat exchanger, it can be stored in the hot water storage tank for domestic hot water in the building, and can also effectively become the energy required by the building. After the gas-liquid separation, the water vapor in the mixed gas is liquefied into water droplets and placed at the bottom of the gas-liquid separator, and gases such as CO2, H2, CO, and CH4 rise to the PSA hydrogen purification device. In the PSA hydrogen compression adsorption purification equipment, hydrogen is separated from other gases and purified, and its purity will become 99.999 Vol%. Other gases in the mixed gas are mainly CO and CO2, which will be stored in the exhaust gas collector. The combustible gas CO and a small amount of CH4 gas in the exhaust gas collector can be mixed in the natural gas pipeline and transported to the building as domestic gas, making the maximum use of the exhaust gas. The hydrogen purified by the PSA hydrogen purification device can be directly used as the raw material of the hydrogen fuel cell device after being compressed to a certain extent by the hydrogen compressor. The hydrogen fuel cell generates electricity to supply the building, and the waste heat generated can be used as a heat source for the water storage tank to heat domestic hot water for the building.

[0154] Compared with the existing waste heat recovery hydrogen production devices, some existing devices only achieve water vapor production through waste heat recovery technology, and then combine with natural gas for mixed reaction conversion to obtain hydrogen. The purpose of the present invention is to complete a gas engine cooling, heating and power trigeneration device based on the basic technology of gas engine power supply. Under the condition of mature hardware technology, the volume of natural gas reforming hydrogen production equipment is reduced and directly connected to the building for application, so that the residual smoke of the gas engine can be effectively utilized, including the direct application of hydrogen, hot water from the heat exchanger generated by hydrogen production, exhaust gas from the exhaust collector, etc., to achieve maximum energy utilization.

Claims

1. A comprehensive energy supply system based on a gas engine residual smoke hydrogen energy storage system, characterized by: It includes gas engines, reforming hydrogen production equipment and lithium bromide absorption hot and cold water units, among which: The input end of the lithium bromide absorption cold and hot water unit is connected to the high-temperature flue gas channel of the gas engine, and its output end is connected to the cold and hot water pipeline for building air conditioning; The reforming hydrogen production equipment includes a residual smoke boiler, a hydrogenation reaction combustion furnace and an intermediate transformer. The first input end of the residual smoke boiler is connected to the high-temperature flue gas pipeline of the gas engine, and the second input end of the residual smoke boiler is connected to the flue gas channel of the hydrogenation reaction combustion furnace; the intermediate transformer is connected to the rear end of the hydrogenation reaction combustion furnace; the terminal hydrogen output end of the reforming hydrogen production equipment is connected to the hydrogen fuel cell; Calculate the total exhaust volume of the gas engine per unit time, and calculate the first flue gas volume required by the lithium bromide absorption cold and hot water unit per unit time; When the total exhaust volume of the gas engine is less than or equal to the first flue gas volume required by the lithium bromide absorption cold and hot water unit, all the flue gas is introduced into the lithium bromide absorption cold and hot water unit; When the total amount of flue gas exhaust from the gas engine is greater than the first flue gas amount required by the lithium bromide absorption cold and hot water unit, a sufficient amount of flue gas is introduced into the lithium bromide absorption cold and hot water unit according to the flue gas amount required by the lithium bromide absorption cold and hot water unit, and the remaining flue gas is introduced into the residual smoke boiler for generating water vapor; the second flue gas amount discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler is determined according to the working state of the hydrogenation reaction combustion furnace; the total flue gas intake amount of the residual smoke boiler is calculated according to the total exhaust amount, the first flue gas amount and the second flue gas amount; The generated water vapor mass flow is calculated according to the total smoke intake, the required natural gas raw material amount is calculated according to the water vapor mass flow and the total carbon flow in the natural gas, and the natural gas is introduced into the hydrogenation reaction combustion furnace according to the natural gas raw material amount.

2. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 1 is characterized in that: Methods for calculating the amount of natural gas feedstock required based on the amount of water vapor and the total carbon flow in the natural gas, including: Calculate the total carbon flow in natural gas based on the proportion of each component gas in natural gas; Determine the water-carbon ratio of natural gas for hydrogen production, and calculate the natural gas volume flow rate based on the water-carbon ratio calculation formula combined with the total carbon flow rate in the natural gas and the water vapor mass flow rate; According to the chemical reaction formula of natural gas to hydrogen production, the amount of natural gas raw material that needs to be imported is calculated in combination with the total carbon flow in the natural gas and the mass flow of water vapor generated by the residual smoke boiler.

3. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 1 is characterized in that: The method for calculating the total amount of smoke exhaust per unit time of a gas engine comprises the following steps: Determine the hourly electricity load demand of the building, and calculate the actual hourly power generation of the gas engine based on the building's green power generation, hydrogen fuel cell power generation, and the rated power generation of the gas engine at full load, as shown in the following formula; ， In the formula is the power generation of the gas engine, is the rated power generation of the gas engine at full load, is the hourly electricity load of the building, Green electricity generation, (kW) is the power generation of the hydrogen fuel cell; Among them, green electricity includes solar or wind power connected to the building; The total exhaust volume of the gas engine generated by the gas engine during power generation is then determined based on the hourly power generation of the gas engine.

4. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 3 is characterized in that: Calculate the total smoke intake of the residual smoke boiler based on the total smoke exhaust volume, the first smoke volume and the second smoke volume (kg / h) method, as shown in the following formula: ， In the formula (kg / h) is the total exhaust volume of the gas engine per unit time, (kg / h) is the first flue gas volume required by the lithium bromide absorption chiller to produce cold or hot water for building cooling or heating. (kg / h) is the second flue gas volume discharged from the hydrogenation reaction combustion furnace and entering the residual smoke boiler.

5. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 4 is characterized in that: The amount of water vapor generated is calculated based on the total smoke intake, which is achieved through the following formula: ， —The mass flow rate of water vapor generated by the residual smoke boiler (kg / h); —Recoverable flue gas waste heat from flue gas boiler (kJ / h); — enthalpy of water vapor during hydrogen reaction (kJ / kg); —Enthalpy of industrial water at room temperature (kJ / kg); —Specific heat capacity of flue gas mass (kJ / (kg·℃)); —The amount of flue gas entering the residual smoke boiler (kg / h); —Average temperature of flue gas at the inlet of residual smoke boiler (℃); —Average flue gas temperature at the outlet of the residual smoke boiler (℃); —Flue gas heat loss coefficient.

6. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 2 is characterized in that: According to the chemical reaction formula of natural gas hydrogen production, the amount of natural gas raw material that needs to be imported is calculated by combining the total carbon flow in the natural gas and the mass flow of water vapor generated by the residual smoke boiler. The specific calculation is through the following formula: The total carbon flow in natural gas is calculated as follows: ， In the formula is the total carbon flow in natural gas, is the volume percentage of methane in natural gas, is the volume percentage of ethane, is the volume percentage of propane, is the volume percentage of butane; Determine the water-carbon ratio of natural gas hydrogen production, and calculate the natural gas volume flow rate based on the water-carbon ratio calculation formula combined with the total carbon flow rate in the natural gas and the water vapor volume flow rate as follows: ， In the formula is the water-carbon ratio, determined as a constant based on experience, is the volume flow rate of natural gas (Nm 3 / h), V steam is the water vapor volume flow rate (Nm 3 / h).

7. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 1 is characterized in that: The reforming hydrogen production equipment also includes a natural gas pipeline, a desulfurizer, a desulfurized natural gas and water vapor mixer, a gas-liquid separator, a hydrogen purification device and an exhaust gas collector, wherein: The first input end of the desulfurized natural gas and water vapor mixer is connected to the water vapor output end of the residual smoke boiler, and the output end of the desulfurized natural gas and water vapor mixer is connected to the hydrogenation reaction combustion furnace; The first output end of the natural gas pipeline is connected to the desulfurizer, and the output end of the desulfurizer is connected to the second input end of the desulfurized natural gas and water vapor mixer; The hydrogenation reaction combustion furnace includes a high-temperature reaction furnace and a flue gas channel, the input end of the high-temperature reaction furnace is connected to the output end of the desulfurized natural gas and water vapor mixer, and the flue gas output end of the flue gas channel is connected to the residual smoke boiler; the output end of the high-temperature reaction furnace is connected to the input end of the medium transformer, the output end of the medium transformer is connected to the input end of the gas-liquid separator, and the output end of the gas-liquid separator is connected to the input end of the hydrogen purification device; The first output end of the hydrogen purification device is connected to the hydrogen power generation device, the second output end of the hydrogen purification device is connected to the exhaust gas collector, and the output end of the exhaust gas collector is connected to the natural gas pipeline.

8. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 7 is characterized in that: Also includes hydrogen compressors and natural gas compressors, The input end of the hydrogen compressor is connected to the hydrogen purification device, and the output end of the hydrogen compressor is connected to the hydrogen power generation device; The input end of the natural gas compressor is connected to the natural gas pipeline, and the output end of the natural gas compressor is connected to the input end of the desulfurizer.

9. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 7 is characterized in that: It also includes a first heat exchanger installed in the connecting pipeline between the high-temperature reaction furnace and the desulfurized natural gas and water vapor mixer; A second heat exchanger, comprising a first cooling channel and a second cooling channel, wherein the first cooling channel is installed in a connecting pipe between the desulfurizer and the high-temperature reaction furnace, and the second cooling channel is installed in a connecting pipe between the compressor and the medium-temperature transformer; The third heat exchanger is installed in the connecting pipeline between the gas-liquid separator and the intermediate transformer.

10. The comprehensive energy supply system based on the gas engine residual smoke hydrogen energy storage system as claimed in claim 9, characterized in that: It also includes a heat storage tank. One end of the third heat exchanger is a cooling water input end, and the other end is output to one input end of the heat storage tank. The other input end of the heat storage tank is connected to the heat output end of the hydrogen power generation device.

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