High heat transfer coefficient hydrogen fuel cell coolant and method of making

Abstract

The application belongs to the technical field of fuel cell temperature control, and discloses a high-heat-conductivity hydrogen fuel cell cooling liquid and a preparation method thereof. The cooling liquid is composed of the following components in parts by weight: 45-55 parts of ethylene glycol, 45-55 parts of deionized water, 0.2-1 part of nano boron nitride dispersion liquid, 0.6-1.8 parts of corrosion and scale inhibitor, 0.2-0.6 parts of ion inhibitor, 0.001-0.1 part of defoaming agent, 0.005-0.01 part of dispersant, 0.005-0.01 part of colorant, and 0.005-0.01 part of buffer. The cooling liquid has the advantages of low conductivity, high heat conductivity and excellent low conductivity retention, and therefore has a good application and promotion prospect.

Description

Technical Field

[0001] This invention relates to the field of fuel cell temperature control technology, specifically to a high heat transfer coefficient hydrogen fuel cell coolant and its preparation method. Background Technology

[0002] Currently, hydrogen energy is an emerging industry in my country's energy sector, and hydrogen fuel cell technology is one of the important technological routes for realizing hydrogen energy utilization. After years of development, my country has initially mastered the core technologies of fuel cell stacks and their key materials, power systems, vehicle integration, and hydrogen energy infrastructure. It has basically established a fuel cell vehicle power system technology platform with independent intellectual property rights, and the gap between China and foreign countries in hydrogen fuel cell vehicles and related supporting industries is continuously narrowing. Particularly in fuel cell systems, the independent research and development progress of leading domestic companies is accelerating significantly, and some indicators of fuel cell system products, such as rated power, start-up temperature, and service life, have reached international leading levels.

[0003] Fuel cells have high energy conversion rates and emit a large amount of heat (approximately 50% of the total energy, 2-3 times that of an engine with the same power output). 95% of this heat is carried away by the coolant. However, if the heat cannot be dissipated in time, thermal runaway can lead to phenomena such as proton exchange membrane dehydration, causing a sharp decline in fuel cell performance. Therefore, temperature control under extreme operating conditions is one of the main challenges facing the commercialization of fuel cells.

[0004] With the successive launches of high-power fuel cells exceeding 100kW, the requirements for internal heat dissipation in the fuel cell stack are becoming increasingly stringent. Especially under extreme operating conditions, heat dissipation has become a critical issue limiting the overall vehicle performance. Currently, the mainstream cooling method for fuel cells is liquid cooling technology, which uses a low-conductivity coolant to remove heat from the fuel cell stack. Faced with this heat dissipation challenge, fuel cell manufacturers and vehicle manufacturers generally focus on improving cooling performance through hardware design and selection of the battery cooling system. This includes improvements to the design and fabrication of bipolar plate cooling channels; increasing the power of the electric water pump to increase the flow rate of the cooling medium; increasing the power of the cooling fan to increase the intake air velocity; and altering the internal structure of the radiator and increasing the number of radiators. However, these methods have reached the bottleneck limits of design power and battery space, making further breakthroughs difficult.

[0005] Therefore, improving the thermal conductivity of the cooling fluid medium, which is a key factor in fuel cell heat dissipation, has become a focus for mainstream fuel cell manufacturers. Innovation in novel liquid cooling materials and thermal conductivity technologies, and in-depth exploration of the thermal conductivity potential of liquid cooling fluid media, are also key technological routes for solving the heat dissipation problem of fuel cells. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a hydrogen fuel cell coolant with low electrical conductivity, high heat transfer coefficient and excellent low electrical conductivity retention performance, and a preparation method thereof.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A high heat transfer coefficient hydrogen fuel cell coolant, the composition of which by weight is as follows:

[0009] 45-55 parts of ethylene glycol

[0010] 45-55 parts deionized water

[0011] 0.2-1 part of nano boron nitride dispersion

[0012] Corrosion and scale inhibitor 0.6-1.8 parts

[0013] Ion inhibitor 0.2-0.6 parts

[0014] Defoamer 0.001-0.1 parts

[0015] Dispersant 0.005-0.01 parts

[0016] Colorant 0.005-0.01 parts

[0017] 0.005-0.01 parts of buffer.

[0018] Preferably, the resistivity of the deionized water is above 16 MΩ·cm.

[0019] Preferably, the nano boron nitride dispersion is an aqueous dispersion of hexagonal nano boron nitride powder with a solid content of 30%, such as YQ-BW01 nano boron nitride from Huzhou Yuanqin New Materials Co., Ltd.

[0020] Preferably, the corrosion and scale inhibitor is a mixture of alkylphenol polyoxyethylene ether, higher alcohol, and imidazoline compounds. Specifically: the alkylphenol polyoxyethylene ether is one or a mixture of several selected from nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, dodecylphenol polyoxyethylene ether, and dinonylphenol polyoxyethylene ether; the higher alcohol is one or a mixture of hexadecyl alcohol and oleyl alcohol; and the imidazoline compound is one or a mixture of several selected from 2-methylimidazoline, 2-ethylimidazoline, and 2-isopropylimidazoline.

[0021] Preferably, the ion inhibitor is one or a mixture of several of the following: methylbenzamide, nicotinamide, pyridinecarboxylate, o-aminobenzamide, succinate, oxalate diamide, xanthan gum, and starch.

[0022] Preferably, the defoamer is a polyether defoamer from the Tuyile® DF-220 series.

[0023] Preferably, the dispersant is one or a mixture of several of the following: sodium hexametaphosphate, ammonium polyacrylate, chitosan, sodium polyacrylate, polyvinyl alcohol, and polyethylene glycol.

[0024] Preferably, the colorant is one or a mixture of several of methyl red, bromomethyl blue and phenol red.

[0025] Preferably, the buffer is one or a mixture of borate and phosphate.

[0026] In addition, the present invention also provides a method for preparing the high heat transfer coefficient hydrogen fuel cell coolant, the method comprising the following steps:

[0027] S1: Add the nano boron nitride dispersion and dispersant to deionized water, and stir at 2200-2700 r / min for 0.5-1.5 h in a high-speed mixer to obtain a uniformly dispersed nano boron nitride solution.

[0028] S2: Mix the nano boron nitride solution obtained in step S1 with ethylene glycol, stir at 700-1000 r / min for 0.5-1.5 h at room temperature, then add corrosion and scale inhibitor and ion inhibitor in sequence, and stir at 700-1000 r / min for 1.5-2.5 h at room temperature.

[0029] S3: Slowly add the defoamer, colorant and buffer to the solution obtained in step S2, and stir at 700-1000 r / min for 0.5-1 h at room temperature;

[0030] S4: After removing solid impurities from the solution obtained in step S3 by an ultrafiltration device, the solution is then subjected to a Spectrapure mixed bed semiconductor-grade DI resin to remove metal and non-metal anions and cations until the conductivity is 0.1 μS / cm to 1 μS / cm, thus obtaining the high heat transfer coefficient hydrogen fuel cell coolant.

[0031] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0032] 1. The hydrogen fuel cell coolant of the present invention has advantages such as low electrical conductivity, high heat transfer coefficient and excellent low electrical conductivity retention, and therefore has good application and promotion prospects.

[0033] 2. The formulation system of the hydrogen fuel cell coolant of this invention: A hexagonal crystal structured boron nitride nano-dispersion is used, which has high thermal conductivity and high resistivity, significantly improving the thermal conductivity of the hydrogen fuel cell coolant by 20%-150%. A suitable metal ion inhibitor is employed to block ions dissolved within the cooling system, maintaining conductivity changes caused by long-term use within the range of 0-8 μS / cm. Tuyile® DF-220 series polyether defoamer is introduced, which has excellent foam suppression and defoaming capabilities, effectively preventing ethylene glycol oxidation and cavitation, thereby improving the metal's corrosion resistance and conductivity retention. A buffer is introduced to control the pH of the coolant at 7-7.5, thus prolonging the corrosion inhibition effect of the corrosion and scale inhibitor. The corrosion and scale inhibitor is a mixture of alkylphenol polyoxyethylene ether, higher alcohols, and imidazoline compounds, which effectively improves the metal's corrosion resistance. Detailed Implementation

[0034] The present invention will be described in detail below with reference to the embodiments, so as to illustrate the features and advantages of the present invention. The following embodiments are not intended to limit the present invention. Formulas prepared by those skilled in the art based on the ideas and raw material ratios of the present invention are also within the protection scope of the present invention.

[0035] The specific preparation method of the coolant in the following embodiments is as follows:

[0036] Nano-boron nitride dispersion and dispersant were added to deionized water and stirred at 2500 rpm for 1 h in a high-speed mixer to obtain a uniformly dispersed nano-boron nitride solution. Ethylene glycol was added to the nano-boron nitride solution and stirred at 800 rpm for 1 h at room temperature. Then, corrosion and scale inhibitors and ion inhibitors were added stepwise, and the mixture was stirred at 800 rpm for 2 h at room temperature. Next, defoamer, colorant, and buffer were slowly added, and the mixture was stirred at 800 rpm for 0.5 h at room temperature. After removing solid impurities from the solution using an ultrafiltration device, the solution was finally passed through a Spectrapeure mixed-bed semiconductor-grade DI resin to remove metal and non-metal anions and cations until the conductivity reached 0.1 μS / cm~1 μS / cm, resulting in a high heat transfer coefficient hydrogen fuel cell coolant.

[0037] The performance testing methods (or standards) for the coolant obtained in the following examples are as follows:

[0038] The thermal conductivity of the coolant was tested using the "Flash Method for Measuring Thermal Diffusion Coefficient or Thermal Conductivity" (GB / T 22588-2008). The metal corrosion resistance of the coolant was tested using the "Engine Coolant Corrosion Determination Method (Glassware Method)" (SH / T 0085-91), and the conductivity of the coolant before and after the test was simultaneously measured using a Shanghai Leici DDS-307A conductivity meter. The foam volume and foam tendency time were measured using the "Engine Coolant Foam Tendency Determination Method (Glassware Method)" (SH / T 0066-2002).

[0039] Example 1

[0040] A high heat transfer coefficient hydrogen fuel cell coolant, comprising the following components by weight: 50 parts ethylene glycol, 50 parts deionized water, 1 part nano boron nitride dispersion, 0.2 parts nonylphenol polyoxyethylene ether, 0.5 parts cetyl alcohol, 0.5 parts 2-methylimidazoline, 0.2 parts methylbenzamide, 0.1 parts xanthan gum, 0.2 parts succinate, 0.05 parts Tuyile® DF-220 series polyether defoamer, 0.005 parts ammonium polyacrylate, 0.005 parts polyvinyl alcohol, 0.008 parts phenol red, and 0.01 parts sodium tetraborate.

[0041] Example 2

[0042] The coolant prepared in this embodiment differs from that in Example 1 in that the nano boron nitride dispersion is 0.2 parts.

[0043] Example 3

[0044] The coolant prepared in this embodiment differs from that in Example 1 in that the nano boron nitride dispersion is 0.6 parts.

[0045] Example 4

[0046] The coolant prepared in this embodiment differs from that in Example 1 in that the nano boron nitride dispersion is 1.2 parts.

[0047] Example 5

[0048] The coolant configured in this embodiment differs from that in Example 1 in that it does not contain methylbenzamide, xanthan gum, or succinate.

[0049] Example 6

[0050] The coolant configured in this embodiment differs from that in Example 1 in that it does not contain Tuyile® DF-220 series polyether defoamer.

[0051] Example 7

[0052] The coolant configured in this embodiment differs from that in Embodiment 1 in that it does not contain sodium tetraborate.

[0053] Example 8

[0054] The coolant prepared in this embodiment differs from that in Example 1 in that it does not contain cetyl alcohol.

[0055] Example 9

[0056] The coolant configured in this embodiment differs from that in Example 1 in that it does not contain 2-methylimidazoline.

[0057] Comparative Example 1

[0058] A coolant, comprising the following components by weight: 50 parts ethylene glycol, 50 parts deionized water, 0.2 parts nonylphenol polyoxyethylene ether, 0.5 parts cetyl alcohol, 0.5 parts 2-methylimidazoline, 0.2 parts methylbenzamide, 0.1 parts xanthan gum, 0.2 parts succinamide, 0.05 parts Tuyile® DF-220 series polyether defoamer, 0.005 parts ammonium polyacrylate, 0.005 parts polyvinyl alcohol, 0.008 parts phenol red, and 0.01 parts sodium tetraborate.

[0059] The test results of the thermal conductivity, metal corrosion resistance, electrical conductivity, foam volume, and foam tendency of the coolant configured in the above embodiments and comparative examples are shown in Table 1.

[0060] Table 1. Test results of coolant thermal conductivity, metal corrosion resistance, electrical conductivity, foam volume, and foam tendency.

[0061]

[0062] Comparing Examples 1-4 and Comparative Example 1, it can be seen that as the content of nano-boron nitride dispersion in the formulation system of the present invention increases, the thermal conductivity of the coolant first increases and then decreases. This is because nano-boron nitride has a significant effect on improving the thermal conductivity of hydrogen fuel cell coolant. However, when the nano-boron nitride dispersion reaches a certain concentration, the stability of the solution system decreases, which has a negative effect on improving the thermal conductivity of hydrogen fuel cell coolant. Comparing Examples 1 and 5, it can be seen that the addition of ion inhibitors has a significant effect on improving the metal corrosion resistance and conductivity retention of hydrogen fuel cell coolant. Comparing Examples 1 and 6, it can be seen that the TuYiLe® DF-220 series polyether defoamer has a significant foam suppression effect while also having a certain metal corrosion resistance and conductivity retention. Comparing Examples 1 and 7, it can be seen that the addition of buffers prolongs the corrosion inhibition effect of corrosion and scale inhibitors while also having a certain conductivity retention. Comparing Example 1 with Examples 8-9, it can be seen that using a mixture of alkylphenol polyoxyethylene ether, higher alcohols and imidazoline compounds can effectively improve the corrosion resistance of metals.

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0064] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high heat transfer coefficient hydrogen fuel cell coolant fluid, characterized by, The components are composed of the following weight parts: Ethylene glycol 45-55 parts Deionized water 45-55 parts Nano boron nitride dispersion liquid 0.2-1 part Corrosion and scale inhibitor 0.6-1.8 parts Ion inhibitor 0.2-0.6 parts Defoaming agent 0.001-0.1 parts Dispersant 0.005-0.01 parts Coloring agent 0.005-0.01 parts Buffer 0.005-0.01 parts; The corrosion and scale inhibitor is a mixture of alkyl phenol polyoxyethylene ether, high alcohol and imidazoline compound; the ion inhibitor is a mixture of one or several of methyl benzamide, nicotinic acid amide, pyridine carboxylic acid amide, o-aminobenzamide, succinic acid amide, oxalic acid diamide, xanthan gum and starch; the defoaming agent is a polyether defoaming agent of DF-220 series; The nano boron nitride dispersion liquid is a water dispersion liquid of hexagonal nano boron nitride powder with a solid content of 30%; The alkyl phenol polyoxyethylene ether is a mixture of one or several of nonyl phenol polyoxyethylene ether, octyl phenol polyoxyethylene ether, dodecyl phenol polyoxyethylene ether and dinonyl phenol polyoxyethylene ether; the high alcohol is a mixture of one or both of cetyl alcohol and oleyl alcohol; the imidazoline compound is a mixture of one or several of 2-methyl imidazoline, 2-ethyl imidazoline and 2-isopropyl imidazoline.

2. The high heat transfer coefficient hydrogen fuel cell coolant of claim 1, wherein: The resistivity of the deionized water is above 16 MΩ·cm.

3. The high heat transfer coefficient hydrogen fuel cell coolant of claim 1, wherein: The dispersant is a mixture of one or several of sodium hexametaphosphate, ammonium polyacrylate, chitosan, polyacrylic acid sodium salt, polyvinyl alcohol and polyethylene glycol; the coloring agent is a mixture of one or several of methyl red, bromomethyl blue and phenol red.

4. The high heat transfer coefficient hydrogen fuel cell coolant of claim 1, wherein: The buffer is a mixture of one or several of borate and phosphate.

5. A method of producing the high heat transfer coefficient hydrogen fuel cell coolant according to any one of claims 1 to 4, characterized by, The method comprises the following steps: S1: add the nano boron nitride dispersion liquid and the dispersant to the deionized water, stir at 2200-2700 r / min in a high-speed stirrer for 0.5-1.5 h to obtain a uniformly dispersed nano boron nitride solution; S2: mix the nano boron nitride solution obtained in step S1 with ethylene glycol, stir at 700-1000 r / min at room temperature for 0.5-1.5 h, then sequentially add the corrosion and scale inhibitor and the ion inhibitor, stir at 700-1000 r / min at room temperature for 1.5-2.5 h; S3: slowly add the defoaming agent, the coloring agent and the buffer to the solution obtained in step S2, stir at 700-1000 r / min at room temperature for 0.5-1 h; S4: remove the solid impurities in the solution obtained in step S3 through an ultra-filtration device, then remove the metal and non-metal anions and cations in the solution through a spectrapure mixed bed semiconductor grade DI resin until the conductivity is 0.1-1 μS / cm, to obtain the high heat transfer coefficient hydrogen fuel cell coolant.

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