Ejecting type reaction device for preparing hydrocarbon fuel through hydrogenation of high-pressure carbon dioxide and design method thereof

Abstract

The invention discloses an injection type reaction device for preparing hydrocarbon fuel through high-pressure carbon dioxide hydrogenation and a design method thereof, the injection type reaction device comprises a reactor and further comprises an injector connected with the reactor in series, the injector comprises a suction chamber, an equal-volume mixing chamber and a diffusion chamber which are communicated in sequence and form a whole, the suction chamber is provided with a first inlet used for arranging a nozzle and a second inlet used for leading in driving fluid. The high-pressure low-speed working fluid is converted into low-pressure high-speed working fluid through the nozzle and enters the suction chamber, negative pressure is formed in the suction chamber, the driving fluid enters the suction chamber, the working fluid and the driving fluid are mixed in the constant-volume mixing chamber, and the mixed gas is pressurized through the diffusion chamber and then flows into a reactor. The gas circulation power consumption is reduced, and the system energy utilization efficiency and the hydrogenation catalytic reaction efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide hydrogenation reaction devices, and in particular to an ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device and a design method thereof. Background Art

[0002] The reaction of carbon dioxide hydrogenation to hydrocarbon fuel is an important way to produce valuable chemicals such as methanol, ethanol, methane, formic acid, dimethyl ether, and syngas. However, in the single-pass reaction, the carbon dioxide hydrogenation catalytic reaction to hydrocarbon fuel still has problems such as low conversion rates of carbon dioxide and hydrogen and low thermodynamic equilibrium conversion rate. Taking the synthesis of green methanol by carbon dioxide hydrogenation as an example, in a single-pass reactor, under the reaction conditions of a reaction pressure of 55 atmospheres and a temperature of 493 K, the thermodynamic equilibrium conversion rate of CO2 is only 40%.

[0003] At present, the methods to improve the conversion rate of carbon dioxide hydrogenation reaction mainly include increasing the inlet gas pressure, tail gas pressurization and recycling, and membrane separation reactors. The forward reaction stoichiometric number of carbon dioxide hydrogenation to green methanol decreases. According to the reaction characteristics, increasing the pressure can promote the forward reaction. However, too high reaction pressure will lead to problems such as increased energy consumption for raw material gas pressurization and high reactor design difficulty. The selective permeation membrane reactor can achieve the instant separation of products and promote the forward reaction. However, the selective permeation membrane has a high cost, poor permeability under medium temperature conditions, and most of them are still in the laboratory research and development stage with little industrial application. Tail gas recycling is the most widely used reaction system at present. Existing research shows that under the conditions of an inlet gas pressure of 55 bar and a temperature of 493 K, the carbon dioxide conversion rate at the thermodynamic equilibrium state of carbon dioxide hydrogenation to methanol in the recycling reaction system can reach 79%.

[0004] Tail gas pressurization and recycling requires the use of pressurization devices. The mainstream industrial pressurization equipment includes compressors or circulation pumps, etc. However, for small and medium-sized carbon dioxide hydrogenation to green methanol reaction devices, the power consumption for driving compressors or circulation pumps is relatively large, and the cost is relatively high, with low cost performance. Summary of the Invention

[0005] Object of the Invention: The first object of the present invention is to provide an ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device, which reduces the gas circulation power consumption, improves the system energy utilization efficiency and the hydrogenation catalytic reaction efficiency.

[0006] The second object of the present invention is to provide a design method for an ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device.

[0007] Technical solution: To achieve the above object, the present invention discloses an ejector-type high-pressure carbon dioxide hydrogenation reaction device for producing hydrocarbon fuels, which includes a reactor and an ejector connected in series with the reactor. The ejector includes a suction chamber, an isochoric mixing chamber, and a diffusion chamber that are connected in sequence and integrated. The suction chamber is provided with a first inlet for setting a nozzle and a second inlet for introducing an ejector fluid. The high-pressure and low-speed working fluid is converted into a low-pressure and high-speed working fluid through the nozzle and enters the suction chamber, forming a negative pressure in the suction chamber. The ejector fluid enters the suction chamber, and the working fluid and the ejector fluid are mixed in the isochoric mixing chamber. The mixed gas flows into the reactor after being pressurized in the diffusion chamber.

[0008] Optionally, the nozzle includes an inlet straight section, a contraction section, a straight section, and an outlet expansion section.

[0009] Optionally, the diameter d of the inlet straight section p is greater than the outlet diameter d of the outlet expansion section p1 is greater than the diameter d of the straight section t .

[0010] Optionally, the isochoric mixing chamber is a chamber with a constant diameter.

[0011] Optionally, the inlet diameter of the diffusion chamber is the same as the diameter of the isochoric mixing chamber, and the outlet diameter of the diffusion chamber is the same as the diameter of the reactor.

[0012] Optionally, the working fluid is a mixture of carbon dioxide and hydrogen or any one of the gases.

[0013] Optionally, the ejector fluid is a low-pressure reaction mixture gas, a reactor tail gas, or a single reaction gas.

[0014] Optionally, the reactor is a tubular reactor.

[0015] Optionally, the reactor is filled with reaction catalyst particles.

[0016] Based on the same inventive concept, the present invention discloses a design method for an ejector-type high-pressure carbon dioxide hydrogenation reaction device for producing hydrocarbon fuels, including the following steps:

[0017] The volumetric space velocity of the reactor under known required operating conditions is Q v , the porosity ε and the particle size d; the total pressure is P g , the total temperature is T g , the required inlet pressure of the reactor is P c , the required temperature of the reactor is T c ;

[0018] According to the definition of volumetric space velocity, establish a calculation formula for the volumetric flow rate V of the reactor inlet gas c :

[0019]

[0020] L is the length of the reactor, and the standard condition pressure P is given N and the standard condition temperature T N ,

[0021] Synchronously derive the intake air mass flow rate where the gas density ρ c is determined through the ideal gas state equation P c = ρ c R g T c , R g is the ideal gas constant, d c is the pipe diameter of the reactor, and ρ c is the density of the mixed gas in the reactor;

[0022] The Ergun equation for a packed bed is used to calculate the reactor pressure drop, and the pressure drop calculation formula is:

[0023]

[0024] Combined with the process allowable pressure drop threshold, the geometric parameter combination of the reactor diameter d c and the length L is optimized through iteration to satisfy ΔP ≤ [ΔP] max constraint condition, where μ is the dynamic viscosity;

[0025] The entrainment ratio is set as Regarding the working fluid as an ideal gas, based on the coupling relationship between the entrainment ratio and the volume space velocity, the ejector nozzle area can be obtained as:

[0026]

[0027] In the formula, R g is the ideal gas constant. According to the ideal gas state equation P c = ρ c R g T c , the gas density ρ c is calculated, η p is the nozzle isentropic efficiency, P g is the total pressure, the total temperature is T g , and γ is the specific heat ratio;

[0028] Through the theoretical formula for the diverging section of the nozzle:

[0029]

[0030] A is calculated p1 , and then according to A t and Ap1 Calculate d separately p1 and d t Then, according to the empirical formula for the length of the extended section and the empirical nozzle expansion angle φ of 10° - 12°, determine the nozzle extended section length L p1 , M p1 is the Mach number of the working fluid at the nozzle outlet; L t is 0.5 - 2 times of d t ; L p is 8 - 10 times of d t ;

[0031] Based on the isentropic relationship Solve for the working fluid pressure P at the nozzle outlet p1 , by simultaneously solving the approximate isentropic relationship equations and Obtain the flow cross-sectional area A of the working fluid in the fluid mixing section py , where is the mainstream loss coefficient; P py is the pressure of the working fluid at the y-y cross-section of the constant-volume mixing chamber, P py = P sy , P sy is the pressure of the entrained fluid at the y-y cross-section of the constant-volume mixing chamber, M py is the Mach number of the working fluid at the y-y cross-section;

[0032] According to the performance analysis of the one-dimensional ejector, under the ejector blockage condition, the Mach number M at the initial mixing point of the working fluid and the entrained fluid sy = 1, and the total pressure of the entrained flow P e = P c - ΔP, then there is Obtain the static pressure P of the initial mixed fluid sy = P py = P m ; The total temperature of the entrained flow m c is the mass flow rate of the reactor inlet air; The mass flow rate of the entrained fluid conforms to the relationship η s is the isentropic efficiency coefficient, and obtain the flow cross-sectional area A of the entrained fluid in the mixing type sy ;

[0033] The area of the constant-volume mixing chamber A3 = A py + A sy , and the length design of the constant-volume mixing chamber has the relationship of L3 = 4 - 10d3 according to the empirical formula, where d3 is the equivalent diameter of the mixing chamber and can be obtained from A3;

[0034] Then, according to the one-dimensional adiabatic steady energy equation, it can be deduced Calculate the temperature T when the fluids are mixed py and T sy ;

[0035] According to the sonic velocity formula, calculate the sonic velocities of the working fluid and the entrained fluid as At this time, the fluid velocity V py = M py c py and V sy = M sy c sy ;

[0036] According to the momentum theorem and the law of conservation of energy:

[0037] φ m (m p V py + m s V sy ) = (m p + m s )V m

[0038]

[0039] where φ m is the momentum loss coefficient caused by friction. By solving the equations simultaneously, the velocity V m and the temperature T m after the fluids are mixed are obtained. The Mach number of the mixed flow is

[0040] Based on the momentum theorem, establish the correlation equations for the velocity, pressure, and temperature parameters before and after the shock wave:

[0041]

[0042]

[0043]

[0044] The velocity V3, pressure P3, and T3 at the outlet section of the constant-volume mixing chamber can be obtained;

[0045] According to the law of conservation of mass, the flow velocity V c at the outlet of the diffuser (inlet of the reactor) and the relationship with V3 are:

[0046]

[0047] where β is the diffusion angle of the diffuser. According to the empirical value, β is taken as 8 - 15°, L c is the length of the diffuser, and d co is the diameter of the outlet of the diffuser.

[0048] Advantages: Compared with the prior art, the present invention has the following remarkable advantages:

[0049] (1) The unreacted tail gas at the outlet of the reactor of the present invention is drawn, pressurized and circulated by an ejector and then re-enters the reactor to complete the hydrogenation catalytic reaction. The ejector uses the pressure energy of the high-speed fluid to drive the circulation. Compared with a compressor, the parasitic work is reduced and the energy utilization efficiency of the system is improved; in the application field of medium and small reaction devices, the ejector has no moving parts compared with a compressor, has a simple structure and low cost;

[0050] (2) By coupling the volumetric space velocity parameter with the dynamic characteristics of the ejector, the present invention realizes the collaborative optimization design of parameters and effectively solves the technical problem that it is difficult to coordinately control the reactor pressure drop and the ejector efficiency in the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic structural diagram of the present invention;

[0052] Figure 2 is a comparison diagram of the methanol vapor production, carbon dioxide conversion rate, and methanol selectivity between the present invention and the reactor without an ejector device under the same inlet gas conditions. DETAILED DESCRIPTION OF THE INVENTION

[0053] The technical solution of the present invention will be further described below with reference to the drawings.

[0054] As Figure 1 shown, an ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device of the present invention includes a reactor 1 and an ejector 2 connected in series with the reactor 1. The ejector 2 includes an inhalation chamber 201, an isochoric mixing chamber 202, and a diffusion chamber 203 that are connected in sequence and integrated. A first inlet 205 for arranging a nozzle 204 and a second inlet 206 for introducing an ejector fluid are provided on the inhalation chamber 201. The high-pressure low-speed working fluid is transformed into a low-pressure high-speed working fluid through the nozzle 204 and enters the inhalation chamber 201, forming a negative pressure in the inhalation chamber 201. The ejector fluid enters the inhalation chamber 201. The working fluid and the ejector fluid are mixed in the isochoric mixing chamber 202, and the mixed gas flows into the reactor 1 after being pressurized by the diffusion chamber 203. The nozzle 204 includes an inlet straight section 207, a contraction section 208, a straight section 209, and an outlet expansion section 210. The diameter d of the inlet straight section 207 p is greater than the outlet diameter d of the outlet expansion section 210 p1 is greater than the diameter d of the straight section 209 t。The constant-volume mixing chamber 202 is a chamber with a constant diameter. The inlet diameter of the diffusion chamber 203 is the same as the diameter of the constant-volume mixing chamber 202, and the outlet diameter of the diffusion chamber 203 is the same as the diameter of the reactor 1. The working fluid is a mixture of carbon dioxide and hydrogen or either of the two gases. The ejector fluid is a low-pressure reaction mixture gas, the reactor tail gas, or a single reaction gas. The reactor is a tubular reactor. The reactor is filled with reaction catalyst particles. For example, the working fluid can be a mixed gas with a mass flow rate of 2.2×10 -4 kg / s, a total pressure of 3.5 MPa, a total temperature of 493 K, and a CO2:H2 stoichiometric ratio of 1:3; the ejector fluid can be a mixed gas with a relatively low total pressure of 2.7 MPa, and the fluid at the outlet of the ejector is a mixed gas of CO2, H2, and CO with a static pressure of 2.7 MPa. The particle size of the catalyst is 0.006 m, the porosity is 0.4, and the catalyst composition is Cu / ZnO / Al2O3. The heat source required for the reactor to drive the reaction can be provided by a trough solar concentrator, and the trough solar concentrator is a conventional structure. As Figure 2 shown, after the design optimization of the ejector reaction device is completed, the system gas mass flow recycle ratio is 0.56, and the CO2 conversion rate is 26.8%. Compared with a single-pass reactor under the same mainstream inlet conditions, the methanol vapor production is increased by more than 1.3 times, greatly improving the material utilization rate and methanol production; compared with a compressor for pressurizing the recycle tail gas, using an ejector device to pressurize and recycle the system tail gas does not generate parasitic work, has no moving parts, and has a simple structure, greatly improving the system energy utilization efficiency and reducing costs.

[0055] A design method for an ejector-type high-pressure carbon dioxide hydrogenation reaction device for producing hydrocarbon fuels includes the following steps:

[0056] The volumetric space velocity of the carbon dioxide hydrogenation catalytic synthesis of green methanol reaction under known required working conditions is Q v = 10000 h -1 , the catalyst packing density ρ cat = 1775 kg / m 3 , the porosity ε = 0.4, and the particle size d = 0.006 m; the gas supply of the working fluid is a mixed gas or a single gas with a stoichiometric ratio of 1:3, the total pressure is P g = 3 MPa, the total temperature is T g = 493 K, the required inlet pressure of the reactor is P c = 2.7 MPa, and the required temperature of the reactor is T c = 493 K;

[0057] Establish a calculation formula for the volumetric flow rate V c of the reactor inlet gas according to the definition of volumetric space velocity:

[0058]

[0059] L is the length of the reactor, given the standard pressure P N and the standard temperature T N , P N = 101325 Pa, T N = 293 K;

[0060] Synchronously deduce the inlet mass flow rate where the gas density ρ c is determined by the ideal gas state equation P c = ρ c R g T c = 9.15 kg / m 3 Determine, R g is the ideal gas constant, d c is the pipe diameter of the reactor, ρ c is the density of the mixed gas in the reactor;

[0061] Use the packed bed Ergun equation to calculate the reactor pressure drop, and the pressure drop calculation formula is:

[0062]

[0063] Combined with the process allowable pressure drop threshold, through iterative optimization of the geometric parameter combination of the reactor diameter d c and the length L, satisfy ΔP ≤ [ΔP] max = 12 kPa constraint condition, μ is the dynamic viscosity; obtain d c = 0.016 m, L = 2 m.

[0064] According to the fluid, to ensure the machinability of the ejector reactor nozzle size, the entrainment ratio is set Regarding the working fluid as an ideal gas, based on the entrainment ratio and the coupling relationship of the volume space velocity, the ejector nozzle area can be obtained as:

[0065]

[0066] In the formula, R g is the ideal gas constant. According to the ideal gas state equation P c = ρ c R g T c , calculate the gas density ρ c , P N = 101325 Pa, T N = 293 K, η p is the nozzle isentropic efficiency, η p takes 0.95, P g is the total pressure, the total temperature is T g , γ is the specific heat ratio;

[0067] Theoretical formula through the nozzle expansion section:

[0068]

[0069] Calculate A p1 , and then according to A t and A p1 Calculate d p1 =0.29mm and d t =0.28mm, and then according to the empirical formula of the extended part length And the empirical nozzle expansion angle φ is 12°, and the nozzle expansion section length L is determined p1 =0.013mm, M p1 is the Mach number of the working fluid at the nozzle outlet, M p1 =1.2; L t is twice d t ; L p 10 times d t ;

[0070] Based on the isentropic relationship Solve for the working fluid pressure P at the nozzle outlet p1 =1.27MPa, by combining the approximate isentropic relationship and Calculate the cross-sectional area A of the working fluid flow in the fluid mixing section py ,in is the mainstream loss coefficient, Take 0.88; P py is the pressure of the working fluid at the yy section of the isochoric mixing chamber, P py =P sy , P sy M is the pressure of the ejected fluid at the isochoric mixing chamber section yy, py is the Mach number of the working fluid at the yy section;

[0071] According to the one-dimensional ejector performance analysis, under ejector blocking conditions, the Mach number M at the initial mixing point of the working fluid and the ejector fluid sy =1, total pressure of jet flow P e =P c -ΔP, then we have Obtain the initial mixed fluid static pressure P sy =P py =P m =1.45MPa; total temperature of the jet flow m c is the reactor inlet mass flow rate; the ejection fluid mass flow rate conforms to the relationship η sis the isentropic efficiency coefficient, and the flow cross-sectional area A of the mixed internal ejector fluid is calculated sy ;

[0072] The area of ​​the isochoric mixing chamber is A3 = A py +A sy The length of the isochoric mixing chamber is designed according to the empirical formula L3 = 8d3 = 3.84 mm, where d3 is the equivalent diameter of the mixing chamber, which can be obtained based on A3, d3 = 0.48 mm;

[0073] According to the one-dimensional adiabatic stability energy equation, we can deduce Calculate the temperature T when the fluids are mixed py With T sy ;

[0074] According to the sound speed formula, the sound speed of the working fluid and the ejection fluid is calculated as follows: At this time, the fluid velocity V py =M py c py and V sy =M sy c sy ;

[0075] According to the law of momentum and the law of conservation of energy:

[0076] φ m (m p V py +m s V sy )=(m p +m s )V m

[0077]

[0078] where φ m is the momentum loss coefficient caused by friction, and the velocity V after fluid mixing is obtained by combining m and temperature T m , The mixed flow Mach number is

[0079] When the gas velocity inside the mixing chamber of the ejector equal cross section reaches the speed of sound or the rear diffusion chamber is blocked, a shock wave will be generated. The Rankine-Hugoniot equation is used to describe the change law of the pressure ratio, temperature ratio and density ratio before and after the shock wave. Based on the momentum theorem, the correlation formula of the velocity, pressure and temperature parameters before and after the shock wave is established:

[0080]

[0081]

[0082]

[0083] The velocity V3, pressure P3, and T3 at the outlet section of the constant-volume mixing chamber can be obtained;

[0084] According to the law of conservation of mass, the flow velocity V at the outlet of the diffuser chamber (inlet of the reactor) can be obtained c The relationship with V3 is:

[0085]

[0086] where β is the diffusion angle of the diffuser chamber. According to the empirical value, β is taken as 15°, and L c is the length of the diffuser chamber, L c = 30.34 mm, and d co is the outlet diameter of the diffuser chamber, d co = 16.62 mm. Due to rounding errors in the calculation, a slight process tolerance of 0.62 mm is allowed between the outlet diameter of the diffuser chamber and the inlet diameter of the reaction section, which can be ignored.

[0087] By coupling the volumetric space velocity parameter with the dynamic characteristics of the ejector, the present invention realizes the collaborative optimization design of parameters, effectively solving the technical problem that it is difficult to coordinately control the reactor pressure drop and the ejector efficiency in the traditional method. The system of the present invention pressurizes and recycles the tail gas without generating parasitic work, has no moving parts, and has a simple structure, greatly improving the energy and material utilization efficiency of the system and reducing costs.

Claims

1. An ejector-type high-pressure carbon dioxide hydrogenation reaction device for producing hydrocarbon fuels, comprising a reactor, characterized in that, It further includes an ejector connected in series with the reactor. The ejector includes a suction chamber, an isochoric mixing chamber, and a diffuser that are connected in sequence and integrated. The suction chamber is provided with a first inlet for arranging a nozzle and a second inlet for introducing an ejecting fluid. The high-pressure and low-speed working fluid is transformed into a low-pressure and high-speed working fluid through the nozzle and enters the suction chamber, forming a negative pressure in the suction chamber. The ejecting fluid enters the suction chamber, and the working fluid and the ejecting fluid are mixed in the isochoric mixing chamber. The mixed gas flows into the reactor after being pressurized by the diffuser.

2. The ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device according to claim 1, wherein: The nozzle includes an inlet straight section, a contraction section, a straight section, and an outlet expansion section.

3. The ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device according to claim 2, wherein: The diameter d of the straight section at the entrance p is greater than the outlet diameter d of the outlet expansion section p1 is greater than the diameter d of the straight section t .

4. The ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device according to claim 1, characterized in that: The isochoric mixing chamber is a chamber with a constant diameter.

5. The ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device according to claim 4, characterized in that: The inlet diameter of the diffuser is the same as the diameter of the isochoric mixing chamber, and the outlet diameter of the diffuser is the same as the diameter of the reactor.

6. The ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device according to claim 1, characterized in that: The working fluid is a mixture of carbon dioxide and hydrogen or any one of the gases.

7. The ejector-type high-pressure carbon dioxide hydrogenation reaction device for producing hydrocarbon fuels according to claim 1, characterized in that: The ejecting fluid is a low-pressure reaction mixed gas, reactor tail gas, or a single reaction gas.

8. The ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device according to claim 1, characterized in that: The reactor is a tubular reactor.

9. The ejector-type high-pressure carbon dioxide hydrogenation to hydrocarbon fuel reaction device according to claim 1, characterized in that: The reactor is filled with reaction catalyst particles.

10. A design method for an ejector-type high-pressure carbon dioxide hydrogenation reaction device for producing hydrocarbon fuels according to any one of claims 1 to 9, characterized in that, It includes the following steps: The reactor volume space velocity under known demand operating conditions is Q v , the porosity ε and the particle size d; the total pressure is P g , the total temperature is T g , the required inlet pressure of the reactor is P c , the required temperature of the reactor is T c ; The volumetric flow rate V of the inlet gas of the reactor is established according to the definition of the space velocity based on volume: c The calculation formula is as follows: L is the length of the reactor, given the standard pressure P N and the standard temperature T N , Synchronous derivation of intake air mass flow rate where the gas density ρ c is determined through the ideal gas state equation P c = ρ c R g T c where R g is the ideal gas constant, d c is the pipe diameter of the reactor, and ρ c is the density of the mixed gas in the reactor; Use the packed bed Ergun equation to calculate the pressure drop of the reactor. The pressure drop calculation formula is: Combined with the process allowable pressure drop threshold, the geometric parameter combination of the reactor diameter d c and the length L is optimized iteratively to satisfy ΔP ≤ [ΔP] max under the constraint condition, where μ is the dynamic viscosity; The entrainment ratio is set as Regarding the working fluid as an ideal gas, based on the coupling relationship between the entrainment ratio and the volumetric space velocity, the ejector nozzle area can be obtained as follows: wherein, R g is the ideal gas constant. According to the ideal gas state equation P c = ρ c R g T c , the gas density ρ c , η p is the isentropic efficiency of the nozzle, P g is the total pressure, the total temperature is T g , and γ is the specific heat ratio; Through the theoretical formula of the nozzle diverging section: Calculate to obtain A p1 , and then based on A t and A p1 , calculate to obtain d p1 and d t , and then according to the empirical formula for the extended part length and the empirical nozzle expansion angle φ being 10° to 12°, determine the nozzle extended section length L p1 , M p1 is the Mach number of the working fluid at the nozzle outlet; L t is 0.5 to 2 times of d t ; L p is 8 to 10 times of d t ; Based on the isentropic relationship Solve for the working fluid pressure P at the nozzle outlet p1 , by simultaneously solving the approximate isentropic relationship equations and Obtain the flow cross-sectional area A of the working fluid in the fluid mixing section py , where is the mainstream loss coefficient; P py is the pressure of the working fluid at the y-y cross-section of the constant-volume mixing chamber, P py = P sy , P sy is the pressure of the entrained fluid at the y-y cross-section of the constant-volume mixing chamber, M py is the Mach number of the working fluid at the y-y cross-section; According to the performance analysis of the one-dimensional ejector, under the blocking condition of the ejector, the Mach number M at the initial mixing point of the working fluid and the entrained fluid is sy = 1, and the total pressure P of the entrained flow e = P c -ΔP, then The static pressure P of the initial mixed fluid is obtained as sy = P py = P m ; The total temperature of the entrained flow m c is the mass flow rate of the reactor inlet air; The mass flow rate of the entrained fluid conforms to the relational expression η s is the isentropic efficiency coefficient, and the flow cross-sectional area A of the entrained fluid in the mixing type is obtained sy ; The area of the constant-volume mixing chamber A3 = A py + A sy , the length of the constant-volume mixing chamber is designed according to the empirical formula with the relationship of L3 = 4 - 10d3, where d3 is the equivalent diameter of the mixing chamber and can be obtained from A3; Based on the one-dimensional adiabatic steady energy equation, it can be deduced that Calculate the temperature T during fluid mixing py and T sy ; According to the sonic velocity formula, the sonic velocities of the working fluid and the entrained fluid are calculated as At this time, the fluid velocity V py = M py c py and V sy = M sy c sy ; According to the momentum theorem and the law of conservation of energy: φ m (m p V py +m s V sy ) = (m p +m s )V m where φ m is the momentum loss coefficient caused by friction, and the velocity V m and temperature T m are obtained by simultaneous equations. The Mach number of the mixed flow is Based on the momentum theorem, establish the correlation formula of the velocity, pressure, and temperature parameters before and after the shock wave: The velocity V3, pressure P3, and T3 at the outlet section of the isochoric mixing chamber can be obtained; According to the law of conservation of mass, the flow velocity V at the outlet of the diffusion chamber (inlet of the reactor) can be obtained c The relationship with V3 is as follows: Among them, β is the diffusion angle of the diffusion chamber, and according to the empirical value, β is taken as 8 - 15°, L c is the length of the diffusion chamber, d co is the diameter of the outlet of the diffusion chamber.

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