Electro-hydrogen-heat comprehensive energy system combined with vortex tube energy recovery

Abstract

The invention discloses an electric hydrogen heat comprehensive energy system combined with vortex tube energy recovery. The system comprises a power grid, a lithium battery, a first-stage vortex tube, a cold end second-stage vortex tube and a hot end second-stage vortex tube, wherein the cold end second-stage vortex tube and the hot end second-stage vortex tube are connected with the cold end and the hot end of the first-stage vortex tube respectively; the lithium battery transmits electric power from a power grid to the electrolytic bath for hydrogen production, obtained hydrogen is input into the primary vortex tube through the compressor and the hydrogen storage tank, and a valve is arranged at the hot end of the primary vortex tube to control a hydrogen supply mode. A synthetic ammonia device is introduced into the hot end of the hot-end secondary vortex tube, so that diversified fuel requirements of a chemical industry park are met, and heat generated by the hot end of the hot-end secondary vortex tube is recycled; the cold end of the hot-end secondary vortex tube is connected with a hydrogen fuel cell, and generated electric energy is supplied to the chemical industry park. And cold energy recovery is performed at the cold end of the cold-end secondary vortex tube, and hydrogen is collected at the hot end and supplied to users in the form of hydrogen-doped natural gas. According to the system, the energy utilization efficiency and flexibility can be greatly improved, energy self-sufficiency is enhanced, and external energy dependence is reduced.

Description

Technical Field

[0001] The present invention relates to the field of integrated energy technology, and in particular to an electric, hydrogen and heat integrated energy system combined with vortex tube energy recovery. Background Art

[0002] With the growth of global energy demand and the emergence of environmental problems, the transformation of energy structure is imminent, and the integrated energy system has become a research hotspot. It integrates various energy forms and aims to improve energy utilization efficiency, reliability and flexibility. However, in actual operation, it still exposes a series of defects: imperfect system coupling and scheduling make it difficult to fully recover high-quality energy such as waste heat and waste pressure, and the overall primary energy utilization rate is low; the proportion of fossil energy is still high, which makes CO2 and NO x The pressure of pollutant emissions remains high; renewable energy sources such as wind power and photovoltaics are difficult to fully absorb due to their intermittent and volatile nature, and curtailment of wind and solar power still occurs frequently; the differences in the time scales and dynamic characteristics of multiple energy media increase the difficulty of coordinated control, which can easily lead to excessive energy consumption and unstable operation. These combined problems have hindered the realization of the true potential of integrated energy systems in achieving energy conservation, emission reduction, and energy transformation goals. Summary of the Invention

[0003] In order to solve the application problems of uneven distribution of electricity and heat energy in traditional energy systems, insufficient efficiency and reliability of energy storage, and inability to effectively cope with fluctuations in energy supply and demand, the present invention proposes an electric-hydrogen-heat integrated energy system with combined vortex tube energy recovery. The system has high overall energy efficiency and good economy.

[0004] To achieve the above objectives, the present invention proposes an electric-hydrogen-heat integrated energy system with vortex tube energy recovery. The integrated energy system includes a power grid, a lithium battery, a primary vortex tube, and a cold-end secondary vortex tube and a hot-end secondary vortex tube connected to the cold end and hot end of the primary vortex tube, respectively. The lithium battery is used to store excess electricity from the power grid and transmit it to the electrolyzer. The hydrogen produced in the electrolyzer is input into the primary vortex tube through a compressor and a hydrogen storage tank.

[0005] The hydrogen undergoes energy separation in the first-stage vortex tube. The hot hydrogen at the hot end outlet of the first-stage vortex tube passes through a valve and enters the hot-end second-stage vortex tube. The hot end of the hot-end second-stage vortex tube is connected to the hot-end heat exchanger, and the heat is stored in the heat storage tank. The hydrogen is input into the ammonia synthesis device to generate ammonia and then input into the chemical park. The cold end of the hot-end second-stage vortex tube is connected to the hydrogen fuel cell. The electricity generated by the hydrogen fuel cell is transmitted to the chemical park for electricity consumption. The electrolyzer and compressor release heat during operation. This heat can be recovered by the waste heat recovery heat exchanger group and stored in the heat storage tank, thereby improving the overall energy utilization efficiency.

[0006] The cold hydrogen at the cold end outlet of the first-level vortex tube enters the cold end secondary vortex tube. The cold end of the cold end secondary vortex tube is connected to the cold end heat exchanger. The cold energy is stored in the cold storage tank. The hydrogen is supplied to the chemical park. The hydrogen at the hot end outlet of the cold end secondary vortex tube is transported to the natural gas pipeline network and supplied to users in the form of hydrogen-blended natural gas.

[0007] A vortex tube is a very simple energy separation device. During operation, compressed gas at a certain pressure enters the nozzle, where it expands and accelerates. It is then ejected tangentially into the vortex chamber at a very high velocity, forming a free vortex. The angular velocity of the free vortex increases as it approaches the center. Due to the different angular velocities, friction occurs between the layers of the free vortex. The hydrogen in the center has the highest velocity. As a result, friction transfers energy to the hydrogen in the outer layers, which have lower angular velocities. The hydrogen in the center loses energy, reducing its kinetic energy, velocity, and temperature. The hydrogen is then drawn out of one end (the cold end) through the orifice plate at the center of the vortex tube, generating cold hydrogen for refrigeration. Meanwhile, the hydrogen in the outer layers gains momentum, increasing its kinetic energy. At the same time, friction with the turbine tube wall converts some of its kinetic energy into heat, which is then converted into hot hydrogen at the hot end of the vortex tube.

[0008] The present invention designs a two-stage vortex tube, and the cold end and hot end of the first-stage vortex tube are respectively connected to the cold-end secondary vortex tube and the hot-end secondary vortex tube, which can effectively recover energy; and a synthetic ammonia device is introduced at the hot end of the hot-end secondary vortex tube to provide the required fuel for the chemical park, meet the diversified fuel needs of the chemical park, and recover the heat generated at the hot end of the hot-end secondary vortex tube. Due to the double-stage recovery of the two-stage vortex tube, the generated heat is much higher than that of the first-stage vortex tube, so the heat storage capacity in the heat storage tank is relatively high, which can meet the high demand state and uncertainty of heat in the chemical park; a hydrogen fuel cell is connected to the cold end of the hot-end secondary vortex tube, and the generated electricity is used to supply power to the chemical park; cold energy is recovered at the cold end of the cold-end secondary vortex tube, and due to the double-stage recovery of the two-stage vortex tube, the generated cold energy is much higher than that of the first-stage vortex tube, so the cold energy storage capacity in the cold storage tank is relatively high, which can meet the high demand state and uncertainty of cold energy in the chemical park, and hydrogen is collected at the hot end of the cold-end secondary vortex tube and supplied to users in the form of hydrogen-blended natural gas.

[0009] The heat generated during the operation of the electrolyzer, compressor and hydrogen fuel cell can be transported into the heat storage tank by the waste heat recovery heat exchanger group for storage, so as to improve the overall energy utilization efficiency of the system.

[0010] The present invention proposes an electric, hydrogen and heat integrated energy system with combined vortex tube energy recovery. A valve is provided at the hot end pipe outlet of the first-level vortex tube. When distributing hot hydrogen, the opening of the valve can be adjusted to change the hydrogen supply mode of the first-level vortex tube, thereby further improving the efficiency and economy of the overall integrated energy system.

[0011] When the demand for heating or electricity is high, the valve opening can be adjusted to increase the hydrogen flow rate entering the hot-end secondary vortex tube to improve the economy of the overall system; when the chemical park has a high demand for hydrogen, the valve opening can be adjusted to increase the hydrogen flow rate in the cold-end secondary vortex tube, thereby increasing the hydrogen flow rate entering the chemical park; when the demand for cooling is high, the valve opening can be adjusted to increase the hydrogen flow rate entering the cold-end secondary vortex tube to improve the overall energy utilization efficiency of the system.

[0012] The specific steps of valve scheduling method are as follows:

[0013] Step S1: Establish the objective function of maximizing the overall energy system benefit:

[0014]

[0015] in:

[0016] R h =x h ·η h ·P h

[0017] R e =x e ·η e ·P e

[0018] R c =x c ·η c ·P c

[0019]

[0020] Where R is the overall energy system benefit, R h and R e and R c and are the energy system’s thermal energy income, electrical energy income, cold energy income and hydrogen energy income, respectively, x h is the heat input to the chemical park, η h Heating efficiency, x e is the amount of electricity input to the chemical park, η e Power supply efficiency, x c is the cooling capacity of the chemical park, η c For cooling efficiency, is the hydrogen flow rate input to the chemical park, Hydrogen supply efficiency, P h 、P e 、P c and are the unit prices of heat energy, electricity energy, cold energy and hydrogen energy respectively, Ch 、C e 、C c and The costs of heat, electricity, cold, and hydrogen are respectively, and the total pipeline hot hydrogen flow is X;

[0021] Constraints:

[0022]

[0023] Step S2: Solving the objective function through an optimization algorithm to obtain the optimal scheduling hot hydrogen flow in different pipelines;

[0024] Step S3: According to the solution results, the valve opening is determined to adjust the hydrogen flow of the four different functions of heating, power supply, cooling and hydrogen supply in the integrated energy system to improve the overall operating efficiency and economy of the integrated energy system.

[0025] The beneficial effects of the present invention are:

[0026] In response to the problems of low energy efficiency, high pollution emissions and energy waste in traditional integrated energy systems, this paper proposes to integrate hydrogen energy and vortex tubes into the traditional integrated energy system and designs an electric hydrogen and heat integrated energy system with energy recovery from vortex tubes. By using renewable electricity to produce hydrogen and storing and peaking it in the system, it can replace part of fossil fuels with hydrogen, significantly reducing CO2 and NO x The two-stage vortex tube is designed to effectively recover energy and improve the absorption capacity of intermittent wind and solar power; the vortex tube is used to separate the energy of compressed hydrogen, efficiently recovering the energy that was originally difficult to use and improving energy utilization; the combined vortex tube energy recovery system constructed by coupling the two has achieved a qualitative leap in technical route, energy conservation and emission reduction performance, and economic feasibility compared with the existing integrated energy system. In addition, this application designs a two-stage vortex tube, which can not only effectively recover energy and meet the diversified fuel needs of chemical parks, but also meet the high demand and uncertainty of heat / cooling in chemical parks. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of an electric, hydrogen and heat integrated energy system combined with vortex tube energy recovery according to the present invention;

[0028] 1 represents the power grid, 2 the lithium battery, 3 the electrolyzer, 4 the compressor, 5 the hydrogen storage tank, 6 the primary vortex tube, 7 the valve, 8 the hot-end heat exchanger, 9 the cold-end heat exchanger, 10 the hydrogen fuel cell, 11 the waste heat recovery heat exchanger, 12 the heat storage tank, 13 the cold storage tank, 14 the chemical park, 15 the natural gas pipeline network, 16 the user, 17 the cold-end secondary vortex tube, 18 the hot-end secondary vortex tube, and 19 the ammonia synthesis plant. Line A represents the hydrogen transmission path, line B represents the electrical energy flow path, line C represents the thermal energy flow path, line D represents the cold energy flow path, line E represents the hydrogen-blended natural gas flow path, and line F represents the ammonia flow path. DETAILED DESCRIPTION

[0029] Example: Figure 1 As shown, the present invention discloses an electric-hydrogen-heat integrated energy system with combined vortex tube energy recovery, which mainly consists of a power grid 1, a lithium battery 2, an electrolyzer 3, a compressor 4, a hydrogen storage tank 5, a primary vortex tube 6, a valve 7, a hot-end heat exchanger 8, a cold-end heat exchanger 9, a hydrogen fuel cell 10, a waste heat recovery heat exchanger group 11, a heat storage tank 12, a cold storage tank 13, a chemical park 14, a natural gas pipeline network 15, a user 16, a cold-end secondary vortex tube 17, a hot-end secondary vortex tube 18 and an ammonia synthesis device 19.

[0030] The lithium battery 2 transmits the electricity obtained from the power grid 1 to the electrolyzer 3 for electrolysis of water to produce hydrogen. The produced hydrogen is pressurized by the compressor 4 and can be stored in the hydrogen storage tank 5 for secondary use, or input into the primary vortex tube 6 for energy separation. After energy separation, the hydrogen is divided into hot hydrogen and cold hydrogen. The hot hydrogen at the hot end outlet of the primary vortex tube 6 passes through the valve 7 and enters the hot end secondary vortex tube 18. The hot end of the hot end secondary vortex tube 18 is connected to the hot end heat exchanger 8, and the heat is stored in the heat storage tank 12. The hydrogen is input into the ammonia synthesis device 19 to generate ammonia and input into the chemical park. The cold end of the hot end secondary vortex tube 18 is connected to the hydrogen fuel cell 10. The electricity generated by the hydrogen fuel cell 10 is transmitted to the chemical park 14 for electricity use. The electrolyzer 3 and the compressor 4 release heat during operation. This heat can be recovered by the waste heat recovery heat exchanger group 11 and stored in the heat storage tank 12, thereby improving the overall energy utilization efficiency.

[0031] The cold hydrogen at the cold end outlet of the first-level vortex tube 6 enters the cold end secondary vortex tube 17. The cold end of the cold end secondary vortex tube 17 is connected to the cold end heat exchanger 9. The cold energy is stored in the cold storage tank 13. The hydrogen is supplied to the chemical park. The hydrogen at the hot end outlet of the cold end secondary vortex tube 17 is transported to the natural gas pipeline network 15 and supplied to the user 16 in the form of hydrogen-mixed natural gas.

[0032] The hot-end pipeline outlet of the first-stage vortex tube is equipped with a valve 7. When hot hydrogen is distributed, the opening of the valve 7 can be adjusted to change the hydrogen supply mode of the first-stage vortex tube 6, further improving the efficiency and economy of the overall integrated energy system. When the demand for heating or electricity is high, the opening of the valve 7 can be adjusted to increase the hydrogen flow entering the hot-end second-stage vortex tube 18 to improve the economy of the overall system; when the demand for hydrogen in the chemical park 14 is high, the opening of the valve 7 can be adjusted to increase the hydrogen flow into the cold-end second-stage vortex tube 17, thereby increasing the hydrogen flow into the chemical park 14; when the demand for cooling is high, the opening of the valve 7 can be adjusted to increase the hydrogen flow into the cold-end second-stage vortex tube to improve the overall energy utilization efficiency of the system.

[0033] The specific dispatching method of valve 7 is as follows:

[0034] Step S1: Establish the objective function of maximizing the overall energy system benefit:

[0035]

[0036] in:

[0037] R h =x h ·η h ·P h

[0038] R e =x e ·η e ·P e

[0039] R c =x c ·η c ·P c

[0040]

[0041] Where R is the overall energy system benefit, R h and R e and R c and are the energy system’s thermal energy income, electrical energy income, cold energy income and hydrogen energy income, respectively, x h is the heat input to the chemical park, η h Heating efficiency, x e is the amount of electricity input to the chemical park, η e Power supply efficiency, x c is the cooling capacity of the chemical park, η c For cooling efficiency, is the hydrogen flow rate input to the chemical park, Hydrogen supply efficiency, Ph 、P e 、P c and are the unit prices of heat energy, electricity energy, cold energy and hydrogen energy respectively, C h 、C e 、C c and The costs of heat, electricity, cold, and hydrogen are respectively, and the total pipeline hot hydrogen flow is X;

[0042] Constraints:

[0043]

[0044] Step S2: Solving the objective function through an optimization algorithm to obtain the optimal scheduling hot hydrogen flow in different pipelines;

[0045] Step S3: According to the solution results, the hydrogen flow rates of the four different functions of heating, power supply, cooling and hydrogen supply in the integrated energy system are adjusted to improve the overall operating efficiency and economy of the integrated energy system.

Claims

1. An electric, hydrogen and heat integrated energy system with vortex tube energy recovery, characterized by: The invention comprises a power grid (1), a lithium battery (2), a primary vortex tube (6), and a cold-end secondary vortex tube (17) and a hot-end secondary vortex tube (18) respectively connected to the cold end and the hot end of the primary vortex tube (6). The lithium battery (2) is used to store excess electricity from the power grid and transmit it to the electrolyzer (3). The hydrogen produced by the electrolyzer (3) is input into the primary vortex tube (6) through a compressor (4) and a hydrogen storage tank (5). The hydrogen undergoes energy separation in the primary vortex tube, and the hot hydrogen at the hot end outlet of the primary vortex tube (6) enters the hot end secondary vortex tube (18) through the valve (7). The hot end of the hot end secondary vortex tube (18) is connected to the hot end heat exchanger (8), and the heat is stored in the heat storage tank (12). The hydrogen is input into the synthetic ammonia device (19) to generate ammonia and input into the chemical park (14). The cold end of the hot end secondary vortex tube (18) is connected to the hydrogen fuel cell (10), and the electric energy generated by the hydrogen fuel cell (10) is transmitted to the chemical park (14) for electricity use. The heat released by the electrolyzer (3) and the compressor (4) during operation is recovered by the waste heat recovery heat exchanger group (11) and stored in the heat storage tank (12). The cold hydrogen at the cold end outlet of the first-stage vortex tube (6) enters the cold end secondary vortex tube (17), the cold end of the cold end secondary vortex tube (17) is connected to the cold end heat exchanger (9), the cold energy is stored in the cold storage tank (13), the hydrogen is supplied to the chemical park (14), and the hydrogen at the hot end outlet of the cold end secondary vortex tube (17) is transported to the natural gas pipeline network (15) and supplied to users (16) in the form of hydrogen-blended natural gas.

2. The electric-hydrogen-heat integrated energy system with vortex tube energy recovery according to claim 1, characterized in that: The valve (7) is provided at the hot end pipeline outlet of the first-stage vortex tube (6). The opening of the valve (7) is adjusted according to the hydrogen and electricity demand of the hot end, thereby changing the hydrogen supply mode of the first-stage vortex tube (6).

3. The electric, hydrogen and heat integrated energy system with vortex tube energy recovery according to claim 2 is characterized by: When the heating demand or the electricity demand is high, the hydrogen flow rate entering the hot-end secondary vortex tube (18) is increased by adjusting the opening of the valve (7); when the hydrogen demand of the chemical park (14) is high or when the cooling demand is high, the hydrogen flow rate of the cold-end secondary vortex tube (17) is increased by adjusting the opening of the valve (7), thereby increasing the hydrogen flow rate entering the chemical park (14) or improving the overall energy utilization efficiency of the system; the specific scheduling method of the valve (7) is as follows: Step S1: Establish the objective function of maximizing the overall energy system benefit: in: R h =x h ·or h ·P h R e =x e ·or e ·P e R c =x c ·or c ·P c Where R is the overall energy system benefit, R h and R e and R c and are the energy system’s thermal energy income, electrical energy income, cold energy income and hydrogen energy income, respectively, x h is the heat input to the chemical park, η h Heating efficiency, x e is the amount of electricity input to the chemical park, η e Power supply efficiency, x c is the cooling capacity of the chemical park, η c For cooling efficiency, is the hydrogen flow rate input to the chemical park, Hydrogen supply efficiency, P h 、P e 、P c and are the unit prices of heat energy, electricity energy, cold energy and hydrogen energy respectively, C h 、C e 、C c and The costs of heat, electricity, cold, and hydrogen are respectively, and the total pipeline hot hydrogen flow is X; Constraints: Step S2: Solving the objective function through an optimization algorithm to obtain the optimal scheduling hot hydrogen flow in different pipelines; Step S3: According to the solution results, the valve opening is determined to adjust the hydrogen flow of the four different functions of heating, power supply, cooling and hydrogen supply in the integrated energy system.

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