Energy consumption optimization system for hydrogen production and hydrogenation integrated station

Abstract

The invention provides an energy consumption optimization system for a hydrogen production and hydrogenation integrated station. A PEM electrolytic cell separates hydrogen and oxygen, an oxygen storage module compresses and stores the oxygen separated by the PEM electrolytic cell, the oxygen storage module supplies room-temperature oxygen to a vortex tube, a hydrogen compression module receives and compresses the hydrogen separated by the PEM electrolytic cell, and a hydrogen compressor supplies hydrogen to a fuel cell vehicle. A first heat exchanger and a second heat exchanger are arranged at the input end and the output end of the hydrogen compression module, the vortex tube separates room-temperature oxygen into cold air and hot air, and the cold air separated by the vortex tube is conveyed to the first heat exchanger and the second heat exchanger; two strands of oxygen passing through the vortex tube are subjected to heat exchange at the two ends of the hydrogen compression module respectively, the heat exchange amount needed for cooling hydrogen in the electrolytic cell to the normal temperature and the heat exchange amount needed for compressing the hydrogen through the hydrogen compressor are small, the oxygen generated by the oxygen storage module can meet the needed heat exchange amount, the cooling capacity of compressed oxygen is utilized to the maximum degree, and the energy consumption is reduced. Dependence on an external chilled water unit is reduced, and the purpose of saving energy is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to an energy consumption optimization system for an integrated hydrogen production and refueling station. Background Art

[0002] The hydrogen needed for fuel cells can be prepared by separating hydrogen and oxygen in the gas using a PEM electrolyzer. The PEM electrolyzer can operate under high pressure, and the back pressure can make the anode and cathode reach a pressure of 5MPa, that is, the hydrogen pressure and oxygen pressure are both 5MPa. So far, the oxygen after the operation of the PEM electrolyzer will be released into the atmosphere, and this part of the compressed gas is not used, wasting a lot of energy. Summary of the invention

[0003] The purpose of the present invention is to provide an energy consumption optimization system for an integrated hydrogen production and refueling station.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A system for optimizing energy consumption of an integrated hydrogen production and refueling station, characterized in that it includes a PEM electrolyzer, a hydrogen compression module, an oxygen storage module, a vortex tube and an oxygen discharge module, wherein the PEM electrolyzer separates hydrogen and oxygen, the oxygen storage module compresses and stores the oxygen separated by the PEM electrolyzer, the oxygen storage module supplies room temperature oxygen to the vortex tube, the hydrogen compression module receives and compresses the hydrogen separated by the PEM electrolyzer, the hydrogen compressor supplies hydrogen to a fuel cell vehicle, the input end and the output end of the hydrogen compression module are respectively provided with a first heat exchanger and a second heat exchanger, the vortex tube separates room temperature oxygen into cold air and hot air, the cold air separated by the vortex tube is transported to the first heat exchanger and the second heat exchanger, the hot air separated by the vortex tube and the hot air after convective heat exchange between the first heat exchanger and the second heat exchanger are combined and transported to the oxygen discharge module, and the oxygen discharge module discharges the oxygen into the outside after stabilizing the pressure.

[0006] Further, the oxygen storage module includes an oxygen exhaust unit and an oxygen storage tank. The oxygen exhaust unit receives oxygen separated by the electrolyzer and discharges it to the oxygen storage tank. The oxygen storage tank stores compressed oxygen.

[0007] Furthermore, the hydrogen compression module includes a hydrogen exhaust unit and a hydrogen compressor. The hydrogen exhaust unit receives the hydrogen separated by the electrolyzer and discharges it to the hydrogen compressor. The hydrogen compressor compresses the hydrogen.

[0008] Furthermore, the output end of the oxygen storage tank is connected to the nozzle in the vortex tube through an air inlet pipe, and room temperature oxygen enters the vortex tube along a tangential direction through the nozzle.

[0009] The present invention exchanges heat at two ends of the hydrogen compression module through two streams of oxygen in the vortex tube. The heat exchange amount required for cooling the hydrogen in the electrolyzer to room temperature and the heat exchange amount required for compressing the hydrogen in the hydrogen compressor are relatively small. The oxygen produced by the oxygen storage module can meet the above required heat exchange amount, thereby maximizing the cooling capacity of the compressed oxygen, reducing dependence on the external chilled water unit, and achieving the purpose of energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0011] Figure 2 Schematic diagram of vortex tube refrigeration capacity, hydrogen production system hydrogen refrigeration capacity, and hydrogen compressor refrigeration capacity.

[0012] Reference numerals:

[0013] 1PEM electrolyzer, 2 oxygen exhaust unit, 3 oxygen storage tank, 4 vortex tube, 5 hydrogen exhaust unit,

[0014] 6 hydrogen compressor, 7 first heat exchanger, 8 second heat exchanger, 9 oxygen exhaust module, 10 fuel cell vehicle. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] The present invention discloses an energy consumption optimization system for a hydrogen production and refueling integrated station, such as Figure 1 As shown, it includes a PEM electrolyzer 1, a hydrogen compression module, an oxygen storage module, a vortex tube 4 and an oxygen discharge module 9. The PEM electrolyzer 1 separates hydrogen and oxygen, the oxygen storage module compresses and stores the oxygen separated by the PEM electrolyzer 1, and the oxygen storage module supplies room temperature oxygen to the vortex tube 4.

[0017] The oxygen storage module includes an oxygen exhaust unit 2 and an oxygen storage tank 3. The oxygen exhaust unit 2 receives oxygen separated by the electrolyzer and discharges it to the oxygen storage tank 3. The oxygen storage tank 3 stores compressed oxygen.

[0018] The hydrogen compression module receives and compresses the hydrogen separated by the PEM electrolyzer 1, and the hydrogen compressor 6 supplies hydrogen to the fuel cell vehicle 10. The input end and the output end of the hydrogen compression module are respectively provided with a first heat exchanger 7 and a second heat exchanger 8. The vortex tube 4 separates the room temperature oxygen into cold air and hot air. The cold air separated by the vortex tube 4 is transported to the first heat exchanger 7 and the second heat exchanger 8.

[0019] The hydrogen compression module includes a hydrogen exhaust unit 5 and a hydrogen compressor 6. The hydrogen exhaust unit 5 receives the hydrogen separated by the electrolyzer and discharges it to the hydrogen compressor 6. The hydrogen compressor 6 compresses the hydrogen.

[0020] like Figure 1 As shown, the output end of the oxygen storage tank 3 is connected to the nozzle in the vortex tube 4 through the air inlet pipe. After the room temperature oxygen expands through the nozzle, it enters the vortex tube 4 at a high speed along the tangential direction to form a free vortex. After the kinetic energy is exchanged, it is separated into two parts with different temperatures. The airflow in the center part of the vortex tube 4 flows out through the orifice plate, which is the cold airflow. The cold airflow is guided to the first heat exchanger 7 and the second heat exchanger 8, and the hydrogen is cooled to the required temperature by convection heat transfer.

[0021] In the present invention, the theoretical temperature drop of the vortex tube 4 can be calculated by the following formula:

[0022]

[0023] in:

[0024] ΔTc is the temperature drop of the cold air flow (unit K),

[0025] ΔTh is the temperature rise of the thermal flow (in K),

[0026] Tin is the gas temperature (in K);

[0027] Pc is the pressure of the cold air flow, which is approximately equal to the atmospheric pressure (unit: Pa).

[0028] Ph is the pressure of the thermal gas flow, which is approximately equal to the pressure of the input gas (unit: Pa).

[0029] Pin is the gas pressure (unit: Pa);

[0030] m is the gas mass flow rate (in kg / s);

[0031] The cold flow ratio y is the ratio of cold air flow to total flow;

[0032] The specific heat ratio of a gas is γ = Cp / Cv, where Cp is the specific heat at constant pressure and Cv is the specific heat at constant volume;

[0033] The actual cooling temperature drop is related to the efficiency of the vortex tube 4, and the efficiency of the vortex tube 4 is expressed by the cold flow temperature drop coefficient η.

[0034] The formula is:

[0035] ΔT 实际 =η×ΔT c

[0036] The cold flow temperature drop coefficient η, i.e. the efficiency of the vortex tube 4, is usually between 0.2 and 0.7, depending on the equipment and operating conditions;

[0037] Finally, the temperature of the cold air flow and the hot air flow can be obtained by the following formula:

[0038] T h =T in +ΔT h

[0039] T c =T in +ΔT c

[0040] The cooling power (cooling capacity) of the vortex tube 4 can be calculated by the cold air flow rate and the cold air temperature drop:

[0041]

[0042] Among them, m c =γ×m, the specific heat capacity ratio γ of the gas is multiplied by the gas mass flow rate m to obtain the mass flow rate of the cold air flow (unit: kg / s), and Cp is the constant pressure specific heat capacity of the cold air;

[0043] In the present invention, the refrigeration capacity of the hydrogen production system is:

[0044] P×V=n×R×T

[0045] Among them, P is the pressure of the gas, V is the volume of the gas, n is the amount of hydrogen (in moles), R is the gas constant of hydrogen, and T is the temperature of the gas (in Kelvin). The refrigeration capacity required for the hydrogen product of the hydrogen production system, that is, the refrigeration capacity of the hydrogen compressor, is obtained.

[0046] The heat generated by the compressor is:

[0047] Q=m×Cp×ΔT / 3600

[0048] Where m is the mass flow rate of hydrogen (kg / h), Cp is the specific heat capacity of hydrogen (J / (g×K)), and ΔT is the temperature change (K);

[0049] Vortex tube cooling capacity > hydrogen production system hydrogen cooling capacity + hydrogen compressor cooling capacity, see Figure 2 ;

[0050]

[0051] In one embodiment, when the PEM electrolyzer 1 is in operation, the hydrogen temperature is 80°C. After the hydrogen is cooled to room temperature of 25°C, subsequent treatment is performed, and the temperature is reduced by 55°C. Here, cooling can be performed by the first heat exchanger 7. When the hydrogen compressor 6 compresses the hydrogen, the heat generation temperature is 400°C. During hydrogenation, it needs to be cooled to below 85°C, and the temperature is reduced by at least 315°C. Here, cooling can be performed by the second heat exchanger 8.

[0052] The hot air separated by the vortex tube 4 and the hot air after convective heat exchange in the first heat exchanger 7 and the second heat exchanger 8 are combined and transported to the oxygen discharge module 9. Finally, the oxygen discharge module 9 discharges the oxygen into the outside after stabilizing the pressure.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy consumption optimization system for a hydrogen production and refueling integrated station, characterized in that: It includes a PEM electrolyzer, a hydrogen compression module, an oxygen storage module, a vortex tube and an oxygen discharge module. The PEM electrolyzer separates hydrogen and oxygen. The oxygen storage module compresses and stores the oxygen separated by the PEM electrolyzer. The oxygen storage module supplies room-temperature oxygen to the vortex tube. The hydrogen compression module receives and compresses the hydrogen separated by the PEM electrolyzer. The hydrogen compressor supplies hydrogen to the fuel cell vehicle. The input end and the output end of the hydrogen compression module are respectively provided with a first heat exchanger and a second heat exchanger. The vortex tube separates room-temperature oxygen into cold air and hot air. The cold air separated by the vortex tube is transported to the first heat exchanger and the second heat exchanger. The hot air separated by the vortex tube and the hot air after convective heat exchange between the first heat exchanger and the second heat exchanger are combined and transported to the oxygen discharge module. The oxygen discharge module discharges the oxygen into the outside after stabilizing the pressure.

2. The energy consumption optimization system for the integrated hydrogen production and refueling station according to claim 1, characterized in that: The oxygen storage module includes an oxygen exhaust unit and an oxygen storage tank. The oxygen exhaust unit receives oxygen separated by the electrolyzer and discharges the oxygen to the oxygen storage tank. The oxygen storage tank stores compressed oxygen.

3. The energy consumption optimization system for the integrated hydrogen production and refueling station according to claim 2 is characterized in that: The hydrogen compression module includes a hydrogen exhaust unit and a hydrogen compressor. The hydrogen exhaust unit receives hydrogen separated by the electrolyzer and discharges it to the hydrogen compressor. The hydrogen compressor compresses hydrogen.

4. The energy consumption optimization system for the integrated hydrogen production and refueling station according to claim 2, characterized in that: The output end of the oxygen storage tank is connected to the nozzle in the vortex tube through an air inlet pipe, and the room temperature oxygen enters the vortex tube along a tangential direction through the nozzle.

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