CN119799289A - A non-ionic low-conductivity coolant and a preparation method thereof - Google Patents

Abstract

The present invention discloses a non-ionic low-conductivity coolant and a preparation method thereof, comprising: the coolant of the present invention is composed of deionized water, ethylene glycol/propylene glycol, benzotriazole and sebacic acid, can effectively reduce conductivity, and is simple to prepare. During preparation, the container is cleaned with ultrapure water, the raw materials are weighed according to mass fraction, added in sequence and stirred evenly, and finally filtered. The results show that the physical and chemical properties of the coolant are close to those of water and ethylene glycol/propylene glycol base liquids, it is compatible with system materials, has good heat dissipation and heat transfer performance, can reduce equipment temperature, improve operating efficiency and stability, and has important practical application value.

Description

Nonionic low-conductivity cooling liquid and preparation method thereof

Technical Field

The invention belongs to the technical field of cooling liquid for fuel cells, and particularly relates to a nonionic low-conductivity cooling liquid and a preparation method thereof.

Background

Hydrogen energy is a secondary energy source with great development prospect in the 21 st century, and fuel cells are an energy revolutionary technology in the 21 st century. The fuel cell is a key device of an energy conversion link in a hydrogen energy industry chain, and is used for converting chemical energy in hydrogen into electric energy, heat energy and other forms, and has the advantages of high efficiency, environmental friendliness, high reliability, high flexibility and the like. In the application link of the hydrogen energy industry chain, the hydrogen fuel cell automobile is widely focused on being suitable for long-distance large-load transportation due to longer endurance. By the end of 2022, the holding quantity of the fuel cell automobiles in the global main country reaches 67315, and the holding quantity of the fuel cell automobiles in China also reaches 12682.

Along with the rising demand of fuel cell automobiles, the demand of a thermal management system of a fuel cell stack is important, namely, the working temperature of the fuel cell is generally in the range of 70-80 ℃, and the radiation and free convection heat exchange quantity of the fuel cell stack are small, so that the selection of cooling liquid is particularly important. Research shows that too high conductivity (5 mu S/cm) of the cooling liquid can cause that the whole vehicle cannot pass through self high-voltage insulation detection when being started, and the whole vehicle cannot be connected with a high-voltage system and started. Meanwhile, because hydrogen and oxygen participate in electrochemical reaction to generate water vapor and gas, the water vapor and gas enter the battery to carry water vapor, and when the cooling liquid flows through the bipolar plate, the electric shock of personnel is avoided, the whole vehicle is safe to operate, and the conductivity is not easy to be too high. The barad fuel cell company specifies that the conductivity of its coolant is below 5 mus/cm, as opposed to just below 100 mus/cm.

Patent CN118325587a discloses a fuel cell automobile antifreeze coolant and a preparation method thereof, wherein ethylene glycol, glycerol, 1, 2-propylene glycol and deionized water are firstly stirred uniformly, then triethanolamine, polyethylene glycol and sebacic acid are added and stirred uniformly, and finally benzotriazole, urotropine and a colorant are added and stirred uniformly. Although the conductivity is less than 2 mu S/cm, the preparation method has low level, but the formula contains various substances, the preparation process is complex, and the solution is sensitive to the conductivity. Patent CN117844456a discloses an ultralow conductivity nanofluid cooling liquid and a preparation method thereof, wherein a base liquid consists of water and ethylene glycol, and isooctanoic acid, methylbenzotriazole, an antirust agent, a defoaming agent, natural lamellar nano-sheets, a PH regulator and the like are used as additives. The addition of the natural lamellar nano-sheets enhances the heat exchange capacity and corrosion inhibition capacity of the cooling liquid, but the nano-materials inevitably have the problems of sedimentation and agglomeration, and the pipeline can be blocked in the use process of the cooling liquid.

Therefore, the development of low-conductivity cooling liquid has important application value. The invention introduces the nonionic cooling liquid, adopts less than three additives, effectively reduces the conductivity, and has simple preparation process and lower cost.

Disclosure of Invention

This section is intended to outline some aspects of embodiments of the application and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description of the application and in the title of the application, which may not be used to limit the scope of the application.

The present invention has been made in view of the above and/or problems occurring in the prior art.

Therefore, the invention aims to overcome the defects in the prior art and provide the nonionic low-conductivity cooling liquid.

In order to solve the technical problems, the invention provides a non-ionic low-conductivity cooling liquid which is characterized by comprising dihydric alcohol, benzotriazole and sebacic acid;

wherein, the mass fraction of the components is 45-50%, the mass fraction of the components is 0.4-0.6%, the mass fraction of the components is 1.6-2.0%, and the mass fraction of the components is 45-55%.

As a preferable scheme of the preparation method, the nonionic low-conductivity cooling liquid comprises 50% of dihydric alcohol, 0.5% of benzotriazole, 1.8% of sebacic acid and 47.7% of deionized water in percentage by mass.

As a preferable mode of the production method of the present invention, the dihydric alcohol includes ethylene glycol and propylene glycol.

The invention further aims to overcome the defects in the prior art and provide a preparation method of the nonionic low-conductivity cooling liquid.

A preparation method of a nonionic low-conductivity cooling liquid is characterized by comprising the following steps of,

Mixing according to the mass percentage, adding dihydric alcohol, benzotriazole and sebacic acid into a reaction kettle, mixing, adding ultrapure water for dilution, stirring uniformly, and filtering.

As a preferable scheme of the preparation method, the mixing and stirring time of the dihydric alcohol and the benzotriazol is 30-50 min.

As a preferable scheme of the preparation method, the dihydric alcohol, the benzotriazole and the sebacic acid are mixed and stirred for 20-40 min.

As a preferable mode of the production method of the present invention, wherein the electric conductivity of the aqueous ultrapure water solution used in the reaction vessel is less than 0.5. Mu.s/cm.

Another object of the present invention is to overcome the deficiencies of the prior art and to provide an application of an ionic low conductivity coolant in a fuel cell vehicle.

The invention has the beneficial effects that:

The physical and chemical properties of the nonionic low-conductivity cooling liquid in the invention are close to those of water and glycol base liquid. This allows the coolant to be well compatible with the various materials in the cooling system during use without adversely affecting the system. Meanwhile, the physical and chemical properties of the water and glycol base liquid are close to each other, so that the cooling liquid is guaranteed to have excellent performances in heat dissipation, heat transfer and the like, the working temperature of equipment can be effectively reduced, the running efficiency and stability of the equipment are improved, and secondly, the antioxidation stability of the cooling liquid is improved. In the long-time use process, the oxidation reaction can be effectively resisted, the deterioration and degradation of the cooling liquid are reduced, and the service life of the cooling liquid is prolonged. This not only reduces the cost of use, but also reduces the environmental impact due to frequent coolant changes. In addition, the cooling liquid of the invention promotes the formation of a natural aluminum passivation layer. This feature can effectively protect the aluminum components in the cooling system from corrosion and damage. Meanwhile, the cooling liquid has no problems of precipitation and instability, ensures the stability and reliability of the cooling liquid in the use process, does not influence the normal operation of a cooling system due to precipitation or instability, and is compatible with an ion exchanger at last, thereby further improving the corrosion resistance performance. This enables the coolant to maintain good corrosion resistance in various complex working environments, effectively protecting metal components in the cooling system, and extending the service life of the cooling system.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:

FIG. 1 is a front-to-back comparison of a metal test piece for metal material compatibility test according to the present invention.

Detailed Description

In order that the above-recited objects, features and advantages of the present invention will become more apparent, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.

Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic can be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

The raw materials used in the examples of the present invention are commercially available except for no specific description, and the details are shown in Table 1.

TABLE 1

Name of the name	Commercial channel	Goods number
			Ethylene glycol	National medicine group chemical reagent Co., ltd	100098193
Propylene glycol	National medicine group chemical reagent Co., ltd	301570197
			Phenylpropiotriazole	Shanghai Aba Ding Keji Co Ltd	B101003-500g
Sebacic acid	National medicine group chemical reagent Co., ltd	30163817

Example 1

(1) The ultrapure water prepared by the water purifier is used for cleaning the reaction kettle, a beaker used in the preparation process and other containers for a plurality of times, so that the conductivity of the ultrapure water aqueous solution is lower than 0.5 mu s/cm;

(2) The raw material components are weighed according to the mass fraction, namely 50 percent of ethylene glycol, 0.5 percent of benzotriazole, 1.8 percent of sebacic acid and 47.7 percent of deionized water;

(3) Adding ethylene glycol into a cleaned reaction kettle, fully stirring to uniformly mix the ethylene glycol, adding the benzotriazole into the reaction kettle, continuously stirring until uniform mixing, adding the sebacic acid into the reaction kettle, uniformly stirring until no turbid matter exists, adding ultrapure water for dilution to ensure that the freezing point is at-37 ℃, and filtering by using filter cloth after uniform stirring.

Example 2

The difference from the examples is that in the step (2), the ethylene glycol is 45%, the benzotriazole is 0.5%, the sebacic acid is 1.8%, and the deionized water is 52.7%

Example 3

The difference from the examples is that in the step (2), propylene glycol is 50%, benzotriazole is 0.5%, sebacic acid is 1.8%, and deionized water is 47.7%

Example 4

The difference from the examples is that in the step (2), propylene glycol is 45%, benzotriazole is 0.5%, sebacic acid is 1.8%, and deionized water is 52.7%

The physical and chemical properties, including freezing point, density, conductivity and PH, of the cooling liquids of examples 1,2,3 and 4 were tested, the relevant instruments and standard methods are shown in table 2, and the test results are shown in table 3. The coolant additives in examples 1,2,3, and 4 were only two, and when dissolved in ethylene glycol/propylene glycol, no ionization occurred.

TABLE 2

TABLE 3 Table 3

The cooling liquid prepared in example 1 was selected for metal material compatibility test, the test was continued at 90 ℃ for 336 hours, the static glassware corrosion test was performed using an aluminum coupon, and the conductivity and PH were increased within a certain range by using an engine cooling liquid corrosion tester according to the standard detection method of national standard SH/T0085, as shown in fig. 1, and table 4 shows the changes in conductivity and PH before and after the test. In the weak acid environment, the aluminum test piece can undergo a corrosion chemical reaction, so that the ion concentration in the solution is increased, and the alkalinity in the solution is enhanced.

TABLE 4 Table 4

The cooling liquid prepared in the example 1 is selected for carrying out a metal material compatibility test, and the standard detection method of the annex E of the national standard GB/T29743.3 is carried out according to the method, wherein PPS and EPDM test pieces are adopted, the test is carried out continuously for 336 hours at 90 ℃, and the conductivity and the PH value change before and after the test are shown in the table 5, so that the conductivity is obviously increased and the change is larger. Some components in the PPS and EPDM test pieces are dissolved in the cooling liquid, so that the ion concentration in the solution is increased, and the conductivity and the PH value are increased.

TABLE 5

FIG. 1 is a front-to-back comparison of a metal test piece for metal material compatibility test according to the present invention.

The physical and chemical properties of the nonionic low-conductivity cooling liquid are close to those of water and glycol-based liquid. This allows the coolant to be well compatible with the various materials in the cooling system during use without adversely affecting the system. Meanwhile, the physical and chemical properties of the water and glycol base liquid are close to each other, so that the cooling liquid is guaranteed to have excellent performances in heat dissipation, heat transfer and the like, the working temperature of the equipment can be effectively reduced, and the running efficiency and stability of the equipment are improved.

Secondly, the cooling liquid improves the oxidation resistance stability. In the long-time use process, the oxidation reaction can be effectively resisted, the deterioration and degradation of the cooling liquid are reduced, and the service life of the cooling liquid is prolonged. This not only reduces the cost of use, but also reduces the environmental impact due to frequent coolant changes. In addition, the cooling liquid of the invention promotes the formation of a natural aluminum passivation layer. This feature can effectively protect the aluminum components in the cooling system from corrosion and damage. Meanwhile, the problems of precipitation and instability are avoided, the stability and the reliability of the cooling liquid in the use process are ensured, and the normal operation of a cooling system is not influenced by precipitation or instability.

Finally, the cooling liquid is compatible with the ion exchanger, and the corrosion resistance performance of the cooling liquid is further improved. This enables the coolant to maintain good corrosion resistance in various complex working environments, effectively protecting metal components in the cooling system, and extending the service life of the cooling system.

In conclusion, the nonionic low-conductivity cooling liquid has excellent performance and reliable stability, can provide effective protection for cooling systems of various devices, and has important practical application value.

It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted without departing from the spirit and scope of the technical solution of the present invention, and it should be covered in the scope of the present invention.

Claims (8)

1. The nonionic low-conductivity cooling liquid is characterized by comprising dihydric alcohol, benzotriazole and sebacic acid;

wherein, the mass fraction of the components is 45-50%, the mass fraction of the components is 0.4-0.6%, the mass fraction of the components is 1.6-2.0%, and the mass fraction of the components is 45-55%.

2. The nonionic low-conductivity coolant of claim 1, wherein the nonionic low-conductivity coolant comprises 50% by mass of glycol, 0.5% by mass of benzotriazole, 1.8% by mass of sebacic acid, and 47.7% by mass of deionized water.

3. The method of claim 2, wherein the glycol comprises ethylene glycol and propylene glycol.

4. A preparation method of a nonionic low-conductivity cooling liquid is characterized by comprising the following steps of,

The preparation method comprises the steps of mixing according to the mass percentage of any one of claims 1-2, adding dihydric alcohol, benzotriazole and sebacic acid into a reaction kettle, mixing, adding ultrapure water for dilution, stirring uniformly, and filtering.

5. The method of claim 4, wherein the mixing and stirring time of the dihydric alcohol and the benzotriazol is 30-50 min.

6. The method of claim 4, wherein the mixing and stirring time of the dihydric alcohol, the benzotriazole and the sebacic acid is 20-40 min.

7. The process according to claim 4, wherein the aqueous ultrapure water solution used in the reaction vessel has a conductivity of less than 0.5. Mu.s/cm.

8. The use of a non-ionic low conductivity coolant according to claims 1-2 in a fuel cell vehicle.