A real-time monitoring method and system for gas evolution side reactions in liquid flow batteries

Abstract

The present invention relates to a real-time monitoring method and system for gas evolution side reactions in a liquid flow battery. The real-time monitoring method for gas evolution side reactions in a liquid flow battery includes collecting the concentration of each side reaction gas, obtaining the gas phase volume in a liquid storage tank, the current test time, the gas phase pressure, and the gas phase temperature in the tank; calculating the increment of each side reaction gas generated by the liquid flow battery in a preset time period according to the sealing condition of the liquid storage tank; calculating the side reaction gas generation rate in a preset time period according to each side reaction gas increment; calculating the side reaction proportion of the liquid flow battery in a preset time period according to the side reaction gas generation rate and the average current in the preset time period. The present invention uses the ideal gas state equation and different constant physical quantities when the liquid storage tank is opened and closed, combined with the working current, to obtain a more accurate gas side reaction proportion at each sampling.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow batteries, and in particular to a real-time monitoring method and system for gas evolution side reactions in liquid flow batteries. Background Art

[0002] In liquid flow batteries, the positive and negative electrodes of all-vanadium liquid flow batteries both use sulfuric acid solutions containing vanadium ions of different valence states as electrolytes. During the charging process of all-vanadium liquid flow batteries, side reactions will inevitably occur. The capacity loss caused by some side reactions (such as vanadium ion cross-membrane crossing, water volume transfer, etc.) can be restored by simple mixing of the liquid; but other side reactions of gas evolution cause Faraday imbalance, which cannot be simply compensated by mixing the liquid. These side reactions will cause the attenuation of coulombic efficiency, voltage efficiency, energy efficiency, and system efficiency, and shorten the life of the liquid flow battery. Therefore, it is particularly necessary to monitor these gas evolution side reactions. Hydrogen, oxygen, and carbon dioxide are the main side reaction gases.

[0003] At present, gas concentration detection instruments are usually used for preliminary testing. However, these gas concentration detection results are related to the operating conditions of the fuel cell stack (such as operating current density, etc.), and it is impossible to eliminate the influence of the operating conditions of the fuel cell stack and evaluate the additional consumption of electrons by side reactions. For example, when the total operating current is 200A, the hydrogen concentration is 1000ppm, and when the total operating current is 400A, the hydrogen concentration is 1300ppm. It is impossible to directly obtain the proportion of hydrogen evolution current to the total operating current, that is, it is impossible to intuitively evaluate how many electrons are wasted in 2H + +2e-→H2 process, instead of the normal cathode reaction: V 3+ +e - →V 2+ .

[0004] Therefore, it is necessary to provide a new, simple and efficient real-time monitoring method for gas evolution side reactions in liquid flow batteries. Summary of the invention

[0005] Based on the above-mentioned problems existing in the prior art, the purpose of the embodiments of the present invention is to provide a simple and efficient real-time monitoring method and system for gas evolution side reactions in liquid flow batteries. By measuring the gas concentration, using the ideal gas state equation and different constant physical quantities when the liquid storage tank is opened and closed, combined with the working current, the calculated proportion of gas side reactions at each sampling is made more accurate.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a real-time monitoring method for gas evolution side reaction of liquid flow battery, comprising:

[0007] Collect the concentration of each side reaction gas in the liquid storage tank respectively;

[0008] Obtain the gas phase volume in the liquid storage tank, the current test time, the gas phase pressure and the gas phase temperature in the tank;

[0009] Calculating the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank;

[0010] Calculating the generation rate of each side reaction gas within the preset time period according to the increment of each side reaction gas generated within the preset time period;

[0011] The side reaction ratio of the liquid flow battery within the preset time period is calculated according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period.

[0012] Furthermore, the step of calculating the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank includes:

[0013] When the liquid storage tank is open and connected to the atmosphere, the calculation of the increment of each side reaction gas generated by the liquid flow battery within a preset time period includes:

[0014] Calculate the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; Calculate the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment;

[0015] According to the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment, the increased volume of each side reaction gas generated in the preset time period in the positive electrode electrolyte storage tank is calculated; according to the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment, the increased volume of each side reaction gas generated in the preset time period in the negative electrode electrolyte storage tank is calculated.

[0016] Furthermore, the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment is calculated by the following formula:

[0017]

[0018]

[0019] in, is the i-th side reaction gas generated at the positive electrode; for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the cathode electrolyte tank, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 ;

[0020] The calculation formula for calculating the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding time is:

[0021]

[0022]

[0023] in, is the jth side reaction gas generated at the negative electrode; for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the negative electrolyte tank, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 ;

[0024] The calculation formula for calculating the increased volume of each side reaction gas generated within a preset time period in the positive electrode electrolyte storage tank is:

[0025]

[0026]

[0027]

[0028] in, express Side reaction gases generated during the time period The volume added in the positive electrolyte tank, in m 3 , for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Gas correction factor in the cathode electrolyte tank during the time period, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for The average volume of the gas phase in the cathode electrolyte tank during the time period, in m 3 , for The total volume of the side reaction gas accumulated in the cathode electrolyte tank during the time period, in m 3 , , The number of types of side reaction gases generated by the positive electrode;

[0029] The calculation formula for calculating the increased volume of each side reaction gas generated within a preset time period in the negative electrode electrolyte storage tank is:

[0030]

[0031]

[0032]

[0033]

[0034] in, for Side reaction gases generated during the time period The volume added in the negative electrolyte tank, in m3, for Side reaction gas The volume in the negative electrode electrolyte tank, in m3, for The gas correction factor in the negative electrolyte tank during the time period, for Side reaction gas The volume in the negative electrode electrolyte tank, in m3, for The average volume of gas phase in the negative electrode electrolyte tank during the time period, in m3, for The total volume of the side reaction gas and the protective gas in the gas phase of the negative electrode electrolyte storage tank increased during the time period, in m3. , is the number of types of side reaction gases generated at the negative electrode, for The volume of the protective gas introduced into the negative electrode electrolyte tank during the time period, in m3, for The volume of the protective gas in the negative electrode electrolyte tank at this time is m3. for The volume of the protective gas in the negative electrode electrolyte storage tank at this time, in m3.

[0035] Furthermore, the step of calculating the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank includes:

[0036] When the liquid storage tank is closed, the step of calculating the increment of each side reaction gas generated by the liquid flow battery within a preset time period includes:

[0037] Calculate the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; calculate the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment;

[0038] Calculate the amount of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the volume, gas phase pressure and gas phase temperature of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; calculate the amount of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the volume, gas phase pressure and gas phase temperature of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment;

[0039] According to the amount of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment, the amount of each side reaction gas generated within the preset time period and accumulated in the positive electrode electrolyte storage tank is calculated; according to the amount of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment, the amount of each side reaction gas generated within the preset time period and accumulated in the negative electrode electrolyte storage tank is calculated.

[0040] Furthermore, the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment is calculated by the following formula:

[0041]

[0042]

[0043] in, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the cathode electrolyte tank, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 ;

[0044] The calculation formula for calculating the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding time is:

[0045]

[0046]

[0047] in, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the negative electrolyte tank, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 .

[0048] Further, the step of calculating the generation rate of each side reaction gas within the preset time period according to the increment of each side reaction gas generated within the preset time period includes:

[0049] When the liquid storage tank is open, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the positive electrode electrolyte storage tank is:

[0050]

[0051]

[0052]

[0053] in, Side reaction gas exist The generation rate in the time period, in mol / s; for Side reaction gases generated during the time period The amount of substance accumulated in the positive electrolyte tank, in mol, for Side reaction gases generated during the time period The amount of substance released, in mol, is the sampling interval, in seconds, for Side reaction gases generated during the time period The volume added in the positive electrolyte tank is in m3. R is the gas constant, which is 8.314 J / (mol·K). for The average gas phase temperature of the cathode electrolyte tank during the time period, in K, for The average gas phase pressure in the cathode electrolyte tank during the time period, in Pa; for The gas correction factor in the cathode electrolyte tank during the time period;

[0054] When the liquid storage tank is open, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the negative electrode electrolyte storage tank is:

[0055]

[0056]

[0057]

[0058] in, for Side reaction gases generated during the time period The amount of substance accumulated in the negative electrode electrolyte tank, in mol, Side reaction gas exist The generation rate in the time period, in mol / s, for Side reaction gases generated during the time period The amount of substance released, in mol, is the sampling interval, in seconds, for The average gas phase temperature of the negative electrode electrolyte tank during the time period, in K, for The average gas phase pressure in the negative electrode electrolyte tank during the time period, in Pa, for Side reaction gases generated during the time period The volume added in the negative electrode electrolyte tank is in m3. R is the gas constant, which is 8.314 J / (mol·K). for Gas correction factor in the negative electrolyte tank during the time period.

[0059] Further, the step of calculating the generation rate of each side reaction gas within the preset time period according to the increment of each side reaction gas generated within the preset time period includes:

[0060] When the liquid storage tank is closed, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the positive electrode electrolyte storage tank is:

[0061]

[0062] in, Indicates side reaction gas exist The generation rate in the time period, in mol / s, is the sampling interval, in seconds, for Side reaction gases generated during the time period The amount of substance accumulated in the cathode electrolyte tank, in mol;

[0063] When the liquid storage tank is closed, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the negative electrode electrolyte storage tank is:

[0064]

[0065] in, Indicates side reaction gas exist The generation rate in the time period, in mol / s, is the sampling interval, in seconds, for Side reaction gases generated during the time period The amount of substance accumulated in the negative electrode electrolyte tank, in mol.

[0066] Furthermore, the side reaction ratio of the flow battery in the preset time period is calculated according to the generation rate of each side reaction gas in the preset time period and the average current in the preset time period, including:

[0067] The calculation formula for the positive electrode side reaction ratio of the flow battery within the preset time period is:

[0068]

[0069] in, for The proportion of positive electrode side reactions in the time period, Indicates side reaction gas exist The generation rate in the time period, in mol / s, , is the number of types of side reaction gases generated at the positive electrode, To represent the side reaction gas The electronic stoichiometric coefficient, F is the Faraday constant, 96485C / mol, for Average current during the time period, A;

[0070] The calculation formula for the proportion of negative electrode side reactions of the flow battery within a preset time period is:

[0071]

[0072] in, for The proportion of negative electrode side reactions in the time period, Indicates side reaction gas exist The generation rate in the time period, in mol / s, , is the number of types of side reaction gases generated at the negative electrode, To represent the side reaction gas The electronic stoichiometric coefficient, F is the Faraday constant, 96485C / mol, for Average current during the time period, A.

[0073] Further, the method further comprises, when the side reaction gas comprises a carbon-containing gas, calculating the corrosion of the carbon material in the flow battery within the preset time period according to the generation rate of each carbon-containing gas within the preset time period;

[0074] The corrosion of the carbon material in the flow battery within the preset time period is calculated according to the generation rate of each carbon-containing gas within the preset time period, and the calculation formula is:

[0075]

[0076] in, for The corrosion ratio of carbon materials in the time period, , is the sum of the types of carbon-containing gases generated at the positive electrode, , is the sum of the types of carbon-containing gases generated at the negative electrode, is the relative atomic mass sum of the carbon atoms contained in the k1th carbon-containing gas generated at the positive electrode, in g / mol, is the relative atomic mass sum of the carbon atoms contained in the k2th carbon-containing gas generated at the negative electrode, in g / mol, The k1th carbon-containing gas generated at the positive electrode The generation rate in the time period, in mol / s, The k2th carbon-containing gas generated at the negative electrode The generation rate in the time period, in mol / s, is the total mass of carbon materials in the battery stack, in g, is the sampling interval, in seconds.

[0077] A real-time monitoring system for gas evolution side reaction in a liquid flow battery, applied to the above-mentioned real-time monitoring method for gas evolution side reaction in a liquid flow battery, the system comprising:

[0078] The first collection module is used to collect the concentration of each side reaction gas in the liquid storage tank respectively;

[0079] The second acquisition module is used to obtain the gas phase volume in the liquid storage tank, the current test time, the gas phase pressure and the gas phase temperature in the tank;

[0080] A gas increment calculation module, used to calculate the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank;

[0081] A gas generation rate calculation module, used to calculate the generation rate of each side reaction gas within a preset time period according to the increment of each side reaction gas generated within a preset time period;

[0082] A side reaction ratio calculation module, used to calculate the side reaction ratio of the flow battery within a preset time period according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period;

[0083] The corrosion condition calculation module is used to calculate the corrosion condition of the carbon material in the liquid flow battery according to the generation rate of each carbon-containing gas within a preset time period when the side reaction gas includes a carbon-containing gas.

[0084] The beneficial effects of the present invention are as follows: a real-time monitoring method for gas evolution side reactions in a liquid flow battery of the present invention comprises: respectively collecting the concentrations of each side reaction gas in the positive electrode liquid storage tank and the negative electrode liquid storage tank of the liquid flow battery; obtaining the gas phase volume in the liquid storage tank, the current test time, the gas phase pressure and the gas phase temperature in the tank; calculating the increment of each side reaction gas generated by the liquid flow battery within a preset time period according to the sealing condition of the liquid storage tank; calculating the generation rate of each side reaction gas within the preset time period according to the increment of each side reaction gas generated within the preset time period; calculating the side reaction proportion of the liquid flow battery within the preset time period according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period; when the side reaction gas is a carbon-containing gas (such as carbon dioxide), the corrosion of the carbon material in the liquid flow battery can also be calculated according to the generation rate of each carbon-containing gas within the preset time period. The real-time monitoring method for gas evolution side reactions in liquid flow batteries of the present invention uses the measured gas concentration, the ideal gas state equation, and different constant physical quantities when the liquid storage tank is opened and closed, combined with the working current, to infer the gas side reaction ratio and carbon corrosion rate at each sampling, which is intuitive and convenient for horizontal comparison; and eliminates the influence of the operating conditions of the fuel cell stack to calculate the ratio of side reaction current, evaluates the corrosion of carbon materials in the fuel cell stack based on the concentration of carbon-containing gas, and can effectively calculate whether the gas phase part of the liquid storage tank is airtight, so that the ratio of side reaction current obtained and the evaluation of the corrosion of carbon materials in the fuel cell stack are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0086] In the figure:

[0087] Figure 1 A flow chart of a method for real-time monitoring of gas evolution side reactions in a liquid flow battery provided by the first embodiment of the present invention;

[0088] Figure 2 A schematic diagram of a battery stack and a liquid storage tank when the liquid storage tank is opened provided in the first embodiment of the present invention;

[0089] Figure 3 A schematic diagram of a battery stack and a liquid storage tank when the liquid storage tank is closed provided in the first embodiment of the present invention;

[0090] Figure 4 A schematic diagram of a module of a real-time monitoring system for gas evolution side reactions in a liquid flow battery provided by a second embodiment of the present invention;

[0091] Figure 5 It is a structural diagram of a network-side server provided according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0092] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are 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.

[0093] First embodiment:

[0094] The first embodiment of the present invention provides a real-time monitoring method for gas evolution side reactions in a liquid flow battery, including: respectively collecting the concentration of each side reaction gas in a liquid storage tank; obtaining the gas phase volume, current test time, gas phase pressure and gas phase temperature in the liquid storage tank; calculating the increment of each side reaction gas generated by the liquid flow battery in a preset time period according to the sealing condition of the liquid storage tank; calculating the generation rate of each side reaction gas in a preset time period according to the increment of each side reaction gas generated in the preset time period; calculating the side reaction proportion of the liquid flow battery in a preset time period according to the generation rate of each side reaction gas in the preset time period and the average current in the preset time period; when the side reaction gas includes a carbon-containing gas (such as carbon dioxide), the corrosion of the carbon material in the liquid flow battery can also be calculated according to the generation rate of each carbon-containing gas in the preset time period. The real-time monitoring method for gas evolution side reactions in a liquid flow battery of the present invention uses the measured gas concentration, the ideal gas state equation and the different constant physical quantities when the liquid storage tank is opened and closed, combined with the working current, so that the calculated gas side reaction proportion and carbon corrosion rate at each sampling are more accurate.

[0095] The following is a detailed description of the implementation details of the real-time monitoring method for gas evolution side reactions in a liquid flow battery according to the present embodiment. The following content is only provided for the convenience of understanding the implementation details and is not necessary for the implementation of the present solution. The specific process of the present embodiment is as follows: Figure 1 shown.

[0096] Step S1, respectively collecting the concentration of each side reaction gas in the positive electrode storage tank and the negative electrode storage tank of the liquid flow battery.

[0097] Specifically, the corresponding gas concentration probe is used to obtain the concentration of each side reaction gas generated by the liquid flow battery.

[0098] When side reaction gases are generated during the operation of the flow battery, the side reaction gases generated by the positive electrode of the flow battery will flow with the positive electrode electrolyte and gather in the positive electrode storage tank, and the side reaction gases generated by the negative electrode will flow with the negative electrode electrolyte and gather in the negative electrode storage tank. The gas concentration probe will detect the concentration changes of each side reaction gas in the positive electrode storage tank and the negative electrode storage tank in real time, and transmit the corresponding signal to the data acquisition device. The operator needs to record the data at a certain time interval, or use the storage function of the data acquisition device to save the gas concentration data during the entire operation period in full for subsequent data analysis. The gas concentration probe can obtain the concentration changes of the side reaction gases generated by the flow battery in real time, so as to grasp the battery operation status in a timely manner.

[0099] Step S2, obtaining the gas phase volume in the liquid storage tank, the current test time, the gas phase pressure and the gas phase temperature in the tank.

[0100] Specifically, a liquid level meter is used to obtain the gas phase volume in the liquid storage tank, which is equal to the difference between the volume of the liquid storage tank itself and the liquid phase volume corresponding to the liquid level. If the liquid storage tank is open, the gas phase pressure can directly use the ambient pressure; if the liquid storage tank is a sealed tank, a pressure gauge is used to obtain the gas phase pressure in the liquid storage tank. A temperature sensor is used to obtain the gas phase temperature in the tank.

[0101] Step S3, calculating the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank.

[0102] like Figure 2 As shown, when the liquid storage tank is open and connected to the atmosphere, protective gas can be passed into the tank to protect the electrolyte from oxidation; or the protective gas can be omitted, and the calculations related only to the protective gas in the following steps can be deleted.

[0103] The step of calculating the increment of each side reaction gas generated by the flow battery within a preset time period includes:

[0104] Step S31, calculate the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; calculate the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment.

[0105] Specifically, the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding time is calculated using the following formula:

[0106]

[0107]

[0108] in, is the i-th side reaction gas generated at the positive electrode, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the cathode electrolyte tank, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas phase volume in the positive electrode electrolyte tank at , m 3 , is the sampling interval, in seconds.

[0109] Specifically, the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding time is calculated using the following formula:

[0110]

[0111]

[0112]

[0113]

[0114] in, is the jth side reaction gas generated at the negative electrode; for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the negative electrolyte tank, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 , for The volume of the protective gas in the negative electrode electrolyte tank at this time, in m 3 , for The sampling concentration of the protective gas in the negative electrode electrolyte tank at the time of the test is in ppm. is the mixing coefficient of the protective gas in the negative electrode electrolyte tank, for The volume of the protective gas in the negative electrode electrolyte tank at this time, in m 3 , for The sampling concentration of the protective gas in the negative electrode electrolyte storage tank at 1000 ℃ is expressed in ppm.

[0115] Further, the mixing coefficient of hydrogen can be 0.7~1, preferably 0.8, the mixing coefficient of oxygen can be 0.8~1.2, preferably 1.1; the mixing coefficient of carbon dioxide can be 0.9~1.3, preferably 1.15; the protective gas is preferably nitrogen, and the mixing coefficient of nitrogen can be 0.8~1.2, preferably 1.08. Step S32, according to the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment, calculate the increased volume of each side reaction gas generated in the positive electrode electrolyte storage tank within the preset time period (sampling interval); according to the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment, calculate the increased volume of each side reaction gas generated in the negative electrode electrolyte storage tank within the preset time period.

[0116] Specifically, the volume of each side reaction gas generated within a preset time period in the positive electrode electrolyte storage tank is calculated using the following formula:

[0117]

[0118]

[0119]

[0120] in, for Gas correction factor in the cathode electrolyte tank during the time period, for The average volume of the gas phase in the cathode electrolyte tank during the time period, in m 3 , for The total volume of the side reaction gas accumulated in the cathode electrolyte tank during the time period, in m 3 , , is the number of types of side reaction gases generated at the positive electrode, express Side reaction gases generated during the time period The volume added in the positive electrolyte tank, in m 3 The meaning of the same parameters is as above, the same below.

[0121] Specifically, the volume of each side reaction gas generated within a preset time period in the negative electrode electrolyte storage tank is calculated using the following formula:

[0122]

[0123]

[0124]

[0125]

[0126] in, for The gas correction factor in the negative electrolyte tank during the time period, for The average volume of gas phase in the negative electrode electrolyte tank during the time period, in m3, for The total volume of the side reaction gas and the protective gas in the gas phase of the negative electrode electrolyte storage tank increased during the time period, in m3. , is the number of types of side reaction gases generated at the negative electrode, for Side reaction gases generated during the time period The volume added in the negative electrolyte tank, in m3, for The volume of the protective gas introduced into the negative electrode electrolyte tank during the time period increases, in m3.

[0127] The above is a calculation formula for the case where the positive electrode electrolyte storage tank is not filled with protective gas and the negative electrode electrolyte storage tank is filled with protective gas. It is applicable to all-vanadium liquid flow batteries. The divalent vanadium ions in the negative electrode electrolyte are easily oxidized, while the positive electrode electrolyte is not easily oxidized. Protective gas can be introduced into the negative electrode electrolyte storage tank to protect the divalent vanadium ions from oxidation. For other liquid flow batteries, there may be situations where the positive electrode electrolyte storage tank needs to be filled with protective gas, while the negative electrode electrolyte storage tank does not need to be filled with protective gas. When solving the gas correction coefficient of the positive electrode electrolyte storage tank and the gas correction coefficient of the negative electrode electrolyte storage tank according to the actual situation, refer to the above formula and choose to add or delete calculations related to the protective gas.

[0128] like Figure 3 As shown, when the liquid storage tank is closed, no protective gas is passed through the liquid storage tank. Calculating the increment of each side reaction gas generated by the liquid flow battery within a preset time period includes:

[0129] Step S31, calculate the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; calculate the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of the side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment.

[0130] Specifically, the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding time is calculated using the following formula:

[0131]

[0132]

[0133] in, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the cathode electrolyte tank, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 .

[0134] Specifically, the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding time is calculated using the following formula:

[0135]

[0136]

[0137] in, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the negative electrolyte tank, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 .

[0138] Step S32, calculate the amount of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the volume, gas phase pressure and gas phase temperature of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; calculate the amount of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the volume, gas phase pressure and gas phase temperature of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment.

[0139] Specifically, the amount of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding time is calculated using the following formula:

[0140]

[0141]

[0142] in, for Side reaction gas The amount of substance in the positive electrolyte tank, in mol, for The gas phase pressure in the positive electrode electrolyte storage tank is in Pa, R is the gas constant, and its value is 8.314 J / (mol·K). for The gas phase temperature in the positive electrode electrolyte tank at , in K, for Side reaction gas The amount of substance in the positive electrolyte tank, in mol, for The gas phase pressure in the positive electrode electrolyte tank at , the unit is Pa, for The gas phase temperature in the positive electrode electrolyte storage tank at , the unit is K.

[0143] Specifically, the amount of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding time is calculated using the following formula:

[0144]

[0145]

[0146] in, for Side reaction gas The amount of substance in the negative electrolyte tank, in mol, for The gas phase pressure in the negative electrode electrolyte storage tank is in Pa. for The gas phase temperature in the negative electrode electrolyte tank at , in K, for Side reaction gas The amount of substance in the negative electrolyte tank, in mol, for The gas phase pressure in the negative electrode electrolyte storage tank is in Pa. for The gas phase temperature in the negative electrode electrolyte storage tank at , in K.

[0147] Step S33, according to the amount of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment, the amount of the substance accumulated in the positive electrode electrolyte storage tank of each side reaction gas generated within the preset time period is calculated; according to the amount of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment, the amount of the substance accumulated in the negative electrode electrolyte storage tank of each side reaction gas generated within the preset time period is calculated.

[0148] Specifically, the amount of each side reaction gas generated within a preset time period accumulated in the positive electrode electrolyte storage tank is calculated using the following formula:

[0149]

[0150] in, for Side reaction gases generated during the time period The amount of substance accumulated in the positive electrolyte tank, in mol.

[0151] Specifically, the amount of each side reaction gas generated within a preset time period accumulated in the negative electrode electrolyte storage tank is calculated using the following formula:

[0152]

[0153] in, for Side reaction gases generated during the time period The amount of substance accumulated in the negative electrode electrolyte tank, in mol.

[0154] Step S4, calculating the generation rate of each side reaction gas within the preset time period according to the increment of each side reaction gas generated within the preset time period.

[0155] When the liquid storage tank is open, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the positive electrode electrolyte storage tank is:

[0156]

[0157]

[0158]

[0159] in, Side reaction gas exist Generation rate during the time period, mol / s; for Side reaction gases generated during the time period The amount of substance accumulated in the positive electrolyte tank, in mol, for Side reaction gases generated during the time period The amount of substance released is in mol. R is the gas constant, which is 8.314 J / (mol·K). for The average gas phase temperature of the cathode electrolyte tank during the time period, in K, for The average gas phase pressure in the positive electrode electrolyte storage tank during the time period, in Pa, is equal to the ambient pressure.

[0160] When the liquid storage tank is open, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the negative electrode electrolyte storage tank is:

[0161]

[0162]

[0163]

[0164] in, for Side reaction gases generated during the time period The amount of substance accumulated in the negative electrode electrolyte tank, in mol, Side reaction gas exist The generation rate in the time period, in mol / s, for Side reaction gases generated during the time period The amount of substance released, in mol, for The average gas phase temperature of the negative electrode electrolyte tank during the time period, in K, for The average gas phase pressure in the negative electrode electrolyte storage tank during the time period, in Pa, is equal to the ambient pressure.

[0165] When the liquid storage tank is closed, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the positive electrode electrolyte storage tank is:

[0166]

[0167] in, Indicates side reaction gas exist The generation rate in the time period, in mol / s, is the sampling interval.

[0168] When the liquid storage tank is closed, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the negative electrode electrolyte storage tank is:

[0169]

[0170] in, Indicates side reaction gas exist The generation rate during the time period, in mol / s.

[0171] Step S5, calculating the side reaction ratio of the flow battery within the preset time period according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period.

[0172] Specifically, the side reaction ratio of the flow battery in the preset time period is calculated according to the generation rate of each side reaction gas in the preset time period and the average current in the preset time period, including:

[0173] Calculation formula for the positive electrode side reaction ratio of flow battery within a preset time period

[0174]

[0175] in, for The proportion of positive electrode side reactions in the time period, , is the number of types of side reaction gases generated at the positive electrode, To represent the side reaction gas The electronic stoichiometric coefficient, F is the Faraday constant, which is 96485 C / mol. for The average current during the time period, in A.

[0176] The calculation formula for the proportion of negative electrode side reactions of the flow battery within a preset time period is:

[0177]

[0178] in, for The proportion of negative electrode side reactions in the time period, , is the number of types of side reaction gases generated at the negative electrode, To represent the side reaction gas The electronic stoichiometric coefficient.

[0179] Step S6, when the side reaction gas is a carbon-containing gas (such as carbon dioxide), the corrosion of the carbon material in the flow battery within the preset time period can also be calculated according to the generation rate of each carbon-containing gas within the preset time period.

[0180] Specifically, the corrosion of the carbon material in the flow battery within the preset time period is calculated according to the carbon-containing gas generation rate within the preset time period, and the calculation formula is:

[0181]

[0182] in, for The corrosion ratio of carbon materials in the time period, , is the sum of the types of carbon-containing gases generated at the positive electrode, , is the sum of the types of carbon-containing gases generated at the negative electrode, is the relative atomic mass sum of the carbon atoms contained in the k1th carbon-containing gas generated at the positive electrode, in g / mol, is the relative atomic mass sum of the carbon atoms contained in the k2th carbon-containing gas generated at the negative electrode, in g / mol, The k1th carbon-containing gas generated at the positive electrode The generation rate in the time period, in mol / s, The k2th carbon-containing gas generated at the negative electrode The generation rate in the time period, in mol / s, It is the total mass of carbon materials (such as carbon felt, bipolar plates, flow channel plates, etc.) in the fuel cell stack, in g.

[0183] A real-time monitoring method for gas evolution side reactions in a liquid flow battery of the present invention comprises: respectively collecting the concentration of each side reaction gas in a liquid flow battery storage tank; obtaining the gas phase volume, current test time, gas phase pressure and gas phase temperature in the liquid storage tank; calculating the increment of each side reaction gas generated by the liquid flow battery in a preset time period according to the sealing condition of the liquid storage tank; calculating the generation rate of each side reaction gas in the preset time period according to the increment of each side reaction gas generated in the preset time period; calculating the side reaction proportion of the liquid flow battery in the preset time period according to the generation rate of each side reaction gas in the preset time period and the average current in the preset time period; when the side reaction gas includes a carbon-containing gas (such as carbon dioxide), the corrosion condition of the carbon material in the liquid flow battery can also be calculated according to the generation rate of each carbon-containing gas in the preset time period. The real-time monitoring method for gas evolution side reactions in liquid flow batteries of the present invention uses the measured gas concentration, the ideal gas state equation, and different constant physical quantities when the liquid storage tank is opened and closed, combined with the working current, to deduce the gas side reaction ratio and carbon corrosion rate at each sampling, which is intuitive and convenient for horizontal comparison; the influence of the operating conditions of the fuel cell stack is eliminated to obtain the ratio of the side reaction current; the corrosion of the carbon material in the fuel cell stack is evaluated according to the carbon dioxide concentration; and the sealing of the gas phase part of the liquid storage tank can be effectively calculated, so that the ratio of the side reaction current obtained and the corrosion of the carbon material in the fuel cell stack can be evaluated more accurately.

[0184] Specific examples are:

[0185] Example 1

[0186] For a conventional all-vanadium liquid flow battery stack being charged, the positive and negative electrode liquid storage tanks are open, and nitrogen is introduced into the negative electrode.

[0187] Step S1, setting the sampling interval, sampling the gas phase of the negative electrode electrolyte storage tank concentration, Concentration and The concentration of the positive electrode electrolyte tank gas phase is sampled. Concentration and Concentration sampling.

[0188] Specifically, the test found that no and ; Negative electrode liquid storage tank detection , not detected , indicating that there are side reactions at the negative electrode. Calculate the ratio of side reactions at the negative electrode.

[0189] Step S2, obtaining the gas phase volume of the negative electrode liquid storage tank, the current test time, the atmospheric pressure and the gas phase temperature in the tank.

[0190] Step S3, calculating the increment of each side reaction gas generated by the flow battery within a preset time period.

[0191] Step S31, according to the negative electrode electrolyte storage tank at the corresponding time concentration, concentration and gas phase volume, calculate the negative electrode electrolyte storage tank at the corresponding time Volume and volume.

[0192] Specifically, calculate the negative electrode electrolyte storage tank at the corresponding time Volume, calculated as:

[0193]

[0194]

[0195] in, for The volume of hydrogen in the negative electrode electrolyte tank at this time, in m 3 , for The sampling concentration of hydrogen in the negative electrode electrolyte tank at 1000 rpm is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 , is the mixing coefficient of hydrogen in the negative electrode electrolyte storage tank, which can be 0.7~1, preferably 0.8, for The volume of hydrogen in the negative electrode electrolyte tank at this time is m3. for The sampling concentration of hydrogen in the negative electrode electrolyte tank at 1000 rpm is in ppm. for The gas volume in the negative electrode electrolyte tank at the time is m3, is the sampling interval, in seconds.

[0196] Specifically, calculate the negative electrode electrolyte storage tank at the corresponding time Volume, calculated as:

[0197]

[0198] in, for The volume of nitrogen in the negative electrode electrolyte tank at this time, in m 3 , for The sampling concentration of nitrogen in the negative electrode electrolyte tank at 10000 hours is in ppm. is the mixing coefficient of nitrogen in the negative electrode electrolyte storage tank. The mixing coefficient of nitrogen can be 0.8~1.2, preferably 1.08. for The volume of nitrogen in the negative electrode electrolyte tank at this time, in m 3 , for The sampling concentration of nitrogen in the negative electrode electrolyte storage tank at 1000 rpm is in ppm.

[0199] Step S32, according to the negative electrode electrolyte storage tank at the corresponding time Volume and Volume, calculated within a preset time period The volume added in the negative electrode electrolyte storage tank is calculated as:

[0200]

[0201]

[0202] in, for The gas correction factor in the negative electrolyte tank during the time period, for The average volume of gas phase in the negative electrode electrolyte tank during the time period, in m3, for The total volume of hydrogen and nitrogen added in the gas phase of the negative electrode electrolyte storage tank during the time period, in m3, for The volume of hydrogen generated in the negative electrode electrolyte tank increased during the time period, in m3. for The volume of nitrogen introduced into the negative electrode electrolyte tank during the time period increases, in m3.

[0203] Step S4, based on the generated The volume increase in the negative electrolyte storage tank is calculated within a preset time period. Spawn rate.

[0204] Specifically, calculate the number of The generation rate is calculated as:

[0205]

[0206]

[0207]

[0208] in, for The amount of hydrogen generated during the time period accumulated in the negative electrode electrolyte tank, in mol, The hydrogen generated at the negative electrode The generation rate in the time period, in mol / s, for The amount of hydrogen generated and released during the time period, in mol, R is the gas constant, which is 8.314 J / (mol·K). for The average gas phase temperature of the negative electrode electrolyte tank during the time period, in K, for The average gas phase pressure in the negative electrode electrolyte storage tank during the time period, in Pa.

[0209] Step S5: according to the preset time period The generation rate and the average current in a preset time period are used to calculate the proportion of negative electrode side reactions in the flow battery.

[0210] Specifically, the calculation formula for calculating the negative electrode side reaction ratio of the flow battery is:

[0211]

[0212] in, for The proportion of negative electrode side reactions in the time period, F is the Faraday constant, which is 96485 C / mol, for The average current during the time period, in A.

[0213] Example 2

[0214] For a conventional all-vanadium liquid flow battery stack that is being charged, the positive and negative electrode liquid storage tanks are closed and no nitrogen is introduced.

[0215] Step S1, setting the sampling interval, sampling the gas phase of the negative electrode electrolyte storage tank Concentration and The concentration of the positive electrode electrolyte tank gas phase is sampled. Concentration and Concentration sampling.

[0216] Specifically, the test found that the negative electrode detected and , detected in the positive electrode liquid storage tank and , indicating that there are side reactions at both the positive and negative electrodes.

[0217] Step S2, respectively obtaining the gas phase volume in the positive and negative electrode storage tanks, the current test time, the atmospheric pressure, and the gas phase temperature in the tanks.

[0218] Step S3, calculating the increment of each side reaction gas generated by the flow battery within a preset time period.

[0219] Calculating the increment of each side reaction gas generated by the flow battery within a preset time period includes the following steps:

[0220] Step S31, according to the negative electrode electrolyte storage tank at the corresponding time concentration, concentration and gas phase volume, calculate the negative electrode electrolyte storage tank at the corresponding time Volume and Volume; according to the positive electrolyte storage tank at the corresponding time concentration, concentration and gas phase volume, calculate the positive electrode electrolyte storage tank at the corresponding time Volume and volume.

[0221] Specifically, calculate the negative electrode electrolyte storage tank at the corresponding time Volume and Volume, calculated as:

[0222]

[0223] in, for The volume of hydrogen in the negative electrode electrolyte tank at this time is m3. for The sampling concentration of hydrogen in the negative electrode electrolyte tank at 1000 rpm is in ppm. for The gas volume in the negative electrode electrolyte tank at the time is m3, is the mixing coefficient of hydrogen in the negative electrode electrolyte storage tank, which can be 0.7~1, preferably 0.8, for The volume of hydrogen in the negative electrode electrolyte tank at this time is m3. for The sampling concentration of hydrogen in the negative electrode electrolyte tank at 1000 rpm is in ppm. for The gas volume in the negative electrode electrolyte tank at the time is m3, for The volume of carbon dioxide in the negative electrode electrolyte storage tank at this time is m3. for The sampling concentration of carbon dioxide in the negative electrode electrolyte tank at 1000 ℃ is in ppm. is the mixing coefficient of carbon dioxide in the negative electrode electrolyte storage tank, which can be 0.9~1.3, preferably 1.15, for The sampling concentration of carbon dioxide in the negative electrode electrolyte tank at 1000 ℃ is in ppm. for The volume of carbon dioxide in the negative electrode electrolyte storage tank at the time, in m3.

[0224] Specifically, calculate the positive electrode electrolyte storage tank at the corresponding time Volume and Volume, calculated as:

[0225]

[0226] in, for The volume of oxygen in the cathode electrolyte tank at this time is m3. for The sampling concentration of oxygen in the cathode electrolyte tank at 10000 hours is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m3, is the mixing coefficient of oxygen in the cathode electrolyte storage tank, which can be 0.8~1.2, preferably 1.1, for The volume of oxygen in the cathode electrolyte tank at this time is m3. for The sampling concentration of oxygen in the cathode electrolyte tank at 10000 hours is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m3, for The volume of carbon dioxide in the cathode electrolyte tank at the time is m3. for The sampling concentration of carbon dioxide in the cathode electrolyte tank at 1000 ℃ is in ppm. The mixing coefficient of carbon dioxide in the cathode electrolyte storage tank can be 0.9 to 1.3, preferably 1.15. for The volume of carbon dioxide in the cathode electrolyte tank at the time is m3. for The sampling concentration of carbon dioxide in the positive electrode electrolyte storage tank at , in ppm.

[0227] Step S32, according to the negative electrode electrolyte storage tank at the corresponding time Volume and Volume, gas phase pressure and gas phase temperature, calculated at the corresponding time and The amount of material in the negative electrode electrolyte storage tank; according to the positive electrode electrolyte storage tank at the corresponding time Volume and Volume, gas phase pressure and gas phase temperature, calculated at the corresponding time and The amount of material in the positive electrolyte reservoir.

[0228] Specifically, calculate at the corresponding time and The amount of material in the negative electrode electrolyte storage tank is calculated as:

[0229]

[0230]

[0231]

[0232]

[0233] in, for The amount of hydrogen in the negative electrode electrolyte tank at the time, in mol, for The gas phase pressure in the negative electrode electrolyte storage tank is in Pa, R is the gas constant, 8.314 J / (mol·K), for The gas phase temperature in the negative electrode electrolyte tank at , in K, for The amount of hydrogen in the negative electrode electrolyte tank at the time, in mol, for The gas phase pressure in the negative electrode electrolyte storage tank is in Pa. for The gas phase temperature in the negative electrode electrolyte tank at , in K, for The amount of carbon dioxide in the negative electrode electrolyte tank at the time, in mol, for The amount of carbon dioxide in the negative electrode electrolyte storage tank at , the unit is mol.

[0234] Specifically, calculate at the corresponding time and The amount of material in the positive electrolyte storage tank is calculated as:

[0235]

[0236] in, for The amount of oxygen in the positive electrolyte tank at the time, in mol, for The gas phase pressure in the positive electrode electrolyte tank at , the unit is Pa, for The gas phase temperature in the negative electrode electrolyte tank at , in K, for The amount of oxygen in the positive electrolyte tank at the time, in mol, for The gas phase pressure in the positive electrode electrolyte tank at , the unit is Pa, for The gas phase temperature in the positive electrode electrolyte tank at , in K, for The amount of carbon dioxide in the cathode electrolyte tank at for The amount of carbon dioxide in the positive electrode electrolyte storage tank.

[0237] Step S33, according to the corresponding time and The amount of material in the negative electrode electrolyte storage tank is calculated within a preset time period. and The amount of material accumulated in the negative electrode electrolyte storage tank; according to the corresponding time and The amount of material in the positive electrolyte storage tank is calculated within a preset time period. and The amount of material accumulated in the positive electrolyte reservoir.

[0238] Specifically, calculate the number of and The amount of material accumulated in the negative electrode electrolyte storage tank is calculated as:

[0239]

[0240] in, for The amount of hydrogen generated during the time period accumulated in the negative electrode electrolyte tank, in mol, for The amount of carbon dioxide accumulated in the negative electrode electrolyte tank during the time period, in mol.

[0241] Specifically, calculate the number of and The amount of material accumulated in the positive electrolyte storage tank is calculated as:

[0242]

[0243] in, for The amount of oxygen generated during the time period accumulated in the positive electrolyte tank, in mol, for The amount of carbon dioxide accumulated in the positive electrode electrolyte tank during the time period, in mol.

[0244] Step S4, calculating the side reaction gas generation rate within the preset time period according to the increment of each side reaction gas generated within the preset time period.

[0245] Specifically, the calculation of the negative electrode generation and The generation rate within a preset time period is calculated as:

[0246]

[0247] in, The hydrogen generated at the negative electrode The generation rate in the time period, in mol / s, is the sampling interval, in seconds, The carbon dioxide generated at the negative electrode The generation rate during the time period, in mol / s.

[0248] Specifically, the calculation of the positive electrode generation and The generation rate within a preset time period is calculated as:

[0249]

[0250] in, The oxygen generated at the positive electrode The generation rate in the time period, in mol / s, The carbon dioxide generated at the positive electrode The generation rate during the time period, in mol / s.

[0251] Step S5, calculating the side reaction ratio of the flow battery within the preset time period according to the generation rate of each side reaction gas generated within the preset time period and the average current within the preset time period.

[0252] Specifically, the side reaction ratio of the flow battery in the preset time period is calculated according to the generation rate of each side reaction gas in the preset time period and the average current in the preset time period, including:

[0253] The calculation formula for the proportion of negative electrode side reactions of the flow battery within a preset time period is:

[0254]

[0255] in, for The proportion of negative electrode side reactions in the time period, F is the Faraday constant, which is 96485 C / mol, for The average current during the time period, in A.

[0256] The calculation formula for the positive electrode side reaction ratio of the flow battery within the preset time period is:

[0257]

[0258] in, for The proportion of positive electrode side reactions within a time period.

[0259] Step S6, calculating the corrosion of the carbon material in the flow battery according to the carbon dioxide generation rate.

[0260] Specifically, the corrosion of carbon materials in flow batteries is calculated based on the carbon dioxide generation rate using the following formula:

[0261]

[0262] in, for The corrosion ratio of carbon materials in the time period, is the relative atomic mass of the carbon atom in carbon dioxide. Carbon dioxide contains 1 carbon atom, so the value is 12g / mol. It is the total mass of carbon materials (such as carbon felt, bipolar plates, flow channel plates, etc.) in the fuel cell stack, in g.

[0263] In addition, different types of battery stacks (such as iron-chromium liquid flow batteries, etc.) may have different side reaction gases. By changing the corresponding side reaction gas detector, the method of the present invention can also be applied.

[0264] Second implementation method:

[0265] like Figure 4 As shown, the second embodiment of the present invention provides a real-time monitoring system for gas evolution side reactions in liquid flow batteries, the system comprising: a first acquisition module 201, a second acquisition module 202, a gas increment calculation module 203, a gas generation rate calculation module 204, a side reaction proportion calculation module 205, and a corrosion condition calculation module 206.

[0266] Specifically, the first acquisition module 201 is used to respectively collect the concentration of each side reaction gas in the liquid flow battery storage tank; the second acquisition module 202 is used to obtain the gas phase volume in the liquid storage tank, the current test time, the gas phase pressure and the gas phase temperature in the tank; the gas increment calculation module 203 is used to calculate the increment of each side reaction gas generated by the liquid flow battery within a preset time period according to the sealing condition of the liquid storage tank; the gas generation rate calculation module 204 is used to calculate the generation rate of each side reaction gas within a preset time period according to the increment of each side reaction gas generated within the preset time period; the side reaction proportion calculation module 205 is used to calculate the side reaction proportion of the liquid flow battery within a preset time period according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period; the corrosion condition calculation module 206 is used to calculate the corrosion condition of the carbon material in the liquid flow battery according to the generation rate of each carbon-containing gas within the preset time period when the side reaction gas includes a carbon-containing gas.

[0267] It is not difficult to find that this embodiment is a system embodiment corresponding to the first embodiment, and this embodiment can be implemented in conjunction with the first embodiment. The relevant technical details mentioned in the first embodiment are still valid in this embodiment, and in order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the first embodiment.

[0268] It is worth mentioning that all modules involved in this embodiment are logic modules. In practical applications, a logic unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, in order to highlight the innovative part of the present invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by the present invention, but this does not mean that there are no other units in this embodiment.

[0269] A third embodiment of the present invention relates to a network side server, such as Figure 5 As shown, it includes at least one processor 302; and a memory 301 that is communicatively connected to the at least one processor 302; wherein the memory 301 stores instructions that can be executed by the at least one processor 302, and the instructions are executed by the at least one processor 302 so that the at least one processor 302 can execute the above-mentioned data processing method.

[0270] The memory 301 and the processor 302 are connected in a bus manner, and the bus may include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors 302 and the memory 301 together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be one element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. The data processed by the processor 302 is transmitted on a wireless medium via an antenna, and further, the antenna also receives data and transmits the data to the processor 302.

[0271] The processor 302 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management and other control functions. The memory 301 can be used to store data used by the processor 302 when performing operations.

[0272] The fourth embodiment of the present invention relates to a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for real-time monitoring of gas evolution side reactions in a liquid flow battery in the first embodiment.

[0273] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0274] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

[0275] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A real-time monitoring method for gas evolution side reactions in a liquid flow battery, characterized in that: include: Collect the concentration of each side reaction gas in the liquid storage tank respectively; Obtain the gas phase volume in the liquid storage tank, the current test time, the gas phase pressure and the gas phase temperature in the tank; Calculating the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank; Calculating the generation rate of each side reaction gas within the preset time period according to the increment of each side reaction gas generated within the preset time period; Calculate the side reaction ratio of the flow battery within the preset time period according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period; The step of calculating the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank includes: When the liquid storage tank is open and connected to the atmosphere, the calculation of the increment of each side reaction gas generated by the liquid flow battery within a preset time period includes: Calculate the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; Calculate the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment; According to the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment, the increased volume of each side reaction gas generated in the preset time period in the positive electrode electrolyte storage tank is calculated; according to the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment, the increased volume of each side reaction gas generated in the preset time period in the negative electrode electrolyte storage tank is calculated.

2. The method for real-time monitoring of gas evolution side reactions in a liquid flow battery according to claim 1, characterized in that: When the liquid storage tank is open and connected to the atmosphere, the step of calculating the increment of each side reaction gas generated by the liquid flow battery within a preset time period includes: The calculation formula for calculating the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding time is: in, is the i-th side reaction gas generated at the positive electrode; for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the cathode electrolyte tank, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the positive electrode electrolyte tank is in ppm. for The gas volume in the positive electrode electrolyte tank at , in m 3 ; The calculation formula for calculating the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding time is: in, is the jth side reaction gas generated at the negative electrode; for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 , Side reaction gas The mixing coefficient in the negative electrolyte tank, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The sampling concentration in the negative electrode electrolyte tank is in ppm. for The gas volume in the negative electrode electrolyte tank at , in m 3 ; The calculation formula for calculating the increased volume of each side reaction gas generated within a preset time period in the positive electrode electrolyte storage tank is: in, express Side reaction gases generated during the time period The volume added in the positive electrolyte tank, in m 3 , for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for Gas correction factor in the cathode electrolyte tank during the time period, for Side reaction gas The volume in the positive electrolyte tank, in m 3 , for The average volume of the gas phase in the cathode electrolyte tank during the time period, in m 3 , for The total volume of the side reaction gas accumulated in the cathode electrolyte tank during the time period, in m 3 , , The number of types of side reaction gases generated by the positive electrode; The calculation formula for calculating the increased volume of each side reaction gas generated within a preset time period in the negative electrode electrolyte storage tank is: in, for Side reaction gases generated during the time period The volume added in the negative electrode electrolyte tank, in m 3 , for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for The gas correction factor in the negative electrolyte tank during the time period, for Side reaction gas The volume in the negative electrode electrolyte tank, in m 3 , for The average volume of the gas phase in the negative electrolyte tank during the time period, in m 3 , for The total volume of the side reaction gas and the protective gas in the gas phase of the negative electrode electrolyte storage tank increased during the time period, in m 3 , , is the number of types of side reaction gases generated at the negative electrode, for The volume of the protective gas introduced into the negative electrode electrolyte tank during the time period, in m 3 , for The volume of the protective gas in the negative electrode electrolyte tank at this time, in m 3 , for The volume of the protective gas in the negative electrode electrolyte tank at this time, in m 3 .

3. The method for real-time monitoring of gas evolution side reactions in a liquid flow battery according to claim 1, characterized in that: The step of calculating the generation rate of each side reaction gas within the preset time period according to the increment of each side reaction gas generated within the preset time period includes: When the liquid storage tank is open, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the positive electrode electrolyte storage tank is: in, Side reaction gas exist The generation rate in the time period, in mol / s; for Side reaction gases generated during the time period The amount of substance accumulated in the positive electrolyte tank, in mol, for Side reaction gases generated during the time period The amount of substance released, in mol, is the sampling interval, in seconds, for Side reaction gases generated during the time period The volume added in the positive electrolyte tank, in m 3 , R is the gas constant, which is 8.314 J / (mol·K), for The average gas phase temperature of the cathode electrolyte tank during the time period, in K, for The average gas phase pressure in the cathode electrolyte tank during the time period, in Pa; for The gas correction factor in the cathode electrolyte tank during the time period; When the liquid storage tank is open, the generation rate of each side reaction gas in the preset time period is calculated according to the increment of each side reaction gas generated in the preset time period. The calculation formula in the negative electrode electrolyte storage tank is: in, for Side reaction gases generated during the time period The amount of substance accumulated in the negative electrode electrolyte tank, in mol, Side reaction gas exist The generation rate in the time period, in mol / s, for Side reaction gases generated during the time period The amount of substance released, in mol, is the sampling interval, in seconds, for The average gas phase temperature of the negative electrode electrolyte tank during the time period, in K, for The average gas phase pressure in the negative electrode electrolyte tank during the time period, in Pa, for Side reaction gases generated during the time period The volume added in the negative electrode electrolyte tank, in m 3 , R is the gas constant, which is 8.314 J / (mol·K), for Gas correction factor in the negative electrolyte tank during the time period.

4. The method for real-time monitoring of gas evolution side reactions in a liquid flow battery according to claim 1, characterized in that: The calculating the side reaction ratio of the flow battery within the preset time period according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period includes: The calculation formula for the positive electrode side reaction ratio of the flow battery within the preset time period is: in, for The proportion of positive electrode side reactions in the time period, Indicates side reaction gas exist The generation rate in the time period, in mol / s, , is the number of types of side reaction gases generated at the positive electrode, To represent the side reaction gas The electronic stoichiometric coefficient, F is the Faraday constant, which is 96485 C / mol. for The average current in the time period, in A; The calculation formula for the proportion of negative electrode side reactions of the flow battery within a preset time period is: in, for The proportion of negative electrode side reactions in the time period, Indicates side reaction gas exist The generation rate in the time period, in mol / s, , is the number of types of side reaction gases generated at the negative electrode, To represent the side reaction gas The electronic stoichiometric coefficient, F is the Faraday constant, which is 96485 C / mol. for The average current during the time period, in A.

5. The method for real-time monitoring of gas evolution side reactions in a liquid flow battery according to claim 1, characterized in that: The method further includes, when the side reaction gas includes a carbon-containing gas, calculating the corrosion of the carbon material in the flow battery within the preset time period according to the generation rate of each carbon-containing gas within the preset time period; The corrosion of the carbon material in the flow battery within the preset time period is calculated according to the generation rate of each carbon-containing gas within the preset time period, and the calculation formula is: in, for The corrosion ratio of carbon materials in the time period, , is the sum of the types of carbon-containing gases generated at the positive electrode, , is the sum of the types of carbon-containing gases generated at the negative electrode, is the relative atomic mass sum of the carbon atoms contained in the k1th carbon-containing gas generated at the positive electrode, in g / mol, is the relative atomic mass sum of the carbon atoms contained in the k2th carbon-containing gas generated at the negative electrode, in g / mol, The k1th carbon-containing gas generated at the positive electrode The generation rate in the time period, in mol / s, The k2th carbon-containing gas generated at the negative electrode The generation rate in the time period, in mol / s, is the total mass of carbon materials in the battery stack, in g, is the sampling interval, in seconds.

6. A real-time monitoring system for gas evolution side reactions in a liquid flow battery, characterized in that: The method for real-time monitoring of gas evolution side reactions in a liquid flow battery according to any one of claims 1 to 5, the system comprising: The first collection module is used to collect the concentration of each side reaction gas in the liquid storage tank respectively; The second acquisition module is used to obtain the gas phase volume in the liquid storage tank, the current test time, the gas phase pressure and the gas phase temperature in the tank; The gas increment calculation module is used to calculate the increment of each side reaction gas generated by the flow battery within a preset time period according to the sealing condition of the liquid storage tank, including: When the liquid storage tank is open and connected to the atmosphere, the calculation of the increment of each side reaction gas generated by the liquid flow battery within a preset time period includes: Calculate the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment; Calculate the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment according to the sampling concentration and gas phase volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment; According to the volume of each side reaction gas in the positive electrode electrolyte storage tank at the corresponding moment, the increased volume of each side reaction gas generated in the positive electrode electrolyte storage tank within the preset time period is calculated; according to the volume of each side reaction gas in the negative electrode electrolyte storage tank at the corresponding moment, the increased volume of each side reaction gas generated in the negative electrode electrolyte storage tank within the preset time period is calculated; A gas generation rate calculation module, used to calculate the generation rate of each side reaction gas within a preset time period according to the increment of each side reaction gas generated within the preset time period; A side reaction ratio calculation module, used to calculate the side reaction ratio of the flow battery within a preset time period according to the generation rate of each side reaction gas within the preset time period and the average current within the preset time period; The corrosion condition calculation module is used to calculate the corrosion condition of the carbon material in the liquid flow battery according to the generation rate of each carbon-containing gas within a preset time period when the side reaction gas includes a carbon-containing gas.

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