CN109722226B

CN109722226B - Environment-friendly mixed refrigerant for replacing R134a and preparation method thereof

Info

Publication number: CN109722226B
Application number: CN201811540743.2A
Authority: CN
Inventors: 吕剑; 杨志强; 唐晓博; 曾纪珺; 张伟; 赵波; 郝志军; 亢建平; 李凤仙
Original assignee: Xian Modern Chemistry Research Institute
Current assignee: Xian Modern Chemistry Research Institute
Priority date: 2018-12-17
Filing date: 2018-12-17
Publication date: 2021-04-13
Anticipated expiration: 2038-12-17
Also published as: CN109722226A

Abstract

The invention discloses an environment-friendly mixed refrigerant for replacing R134a and a preparation method thereof. An environment-friendly mixed refrigerant for replacing R134a is composed of 3,3, 3-trifluoropropene, difluoromethane and 1,1,1, 2-tetrafluoroethane according to mole percentageComprises the following steps: 29-92% of 3,3, 3-trifluoropropene, 3-20% of difluoromethane and 5-61% of 1,1,1, 2-tetrafluoroethane. 3,3, 3-trifluoropropene, 1,1,2, 2-tetrafluoroethane and other substances are added into the 1,1,1, 2-tetrafluoroethane, so that the environmental protection performance of the mixed refrigerant is improved, and the GWP value is greatly reduced relative to R134 a. In addition, the environment-friendly mixed refrigerant prepared by the invention has excellent thermal parameters and thermal performance, the cycle efficiency, the refrigeration coefficient and the unit volume refrigerating capacity in a refrigerating system are superior to R134a or equivalent to R134a, and the saturated vapor pressure is similar to R134a, so that R134a can be directly replaced. The invention also discloses an environment-friendly mixed refrigerant, and Fe is added into the mixture₂O₃、MnO₂ZnO or Al₂O₃Nano particles, thereby improving the compatibility between the refrigerant and the mineral-type refrigerator oil.

Description

Environment-friendly mixed refrigerant for replacing R134a and preparation method thereof

Technical Field

The invention relates to a mixed refrigerant, in particular to an environment-friendly mixed refrigerant replacing R134a and a preparation method thereof.

Background

R134a is a widely used refrigerant for automobile air-conditioner in China and internationally, and has been used as a substitute for R12 refrigerant because it has no ozone depletion effect. However, R134a still has a strong greenhouse gas effect (GWP value of 1550). At present, the automobile industry in China is in a high-speed growth stage, and the automobile holding amount in China is expected to increase by 1.9 hundred million in 2030 compared with 2015. Meanwhile, as the installation rate of the air conditioner of the light passenger vehicle approaches 100%, the discharge of the refrigerant of the air conditioner of the automobile will continuously increase along with the economic growth.

In recent years, global warming has been increasing, and countries around the world are increasingly advancing the replacement of Hydrofluorocarbon (HFCs) refrigerants in order to cope with climate change. Research shows that the emission of HFCs refrigerant is limited on the global scale, the global air temperature rise can be slowed down by 0.5 ℃ at the end of the century, and great contribution can be made to the suppression of global warming. Currently, european union countries and the united states have established a clear policy for automotive air conditioning refrigerant management that R134a is forbidden in newly produced light passenger car air conditioners in 2017 and 2021, respectively. At present, China is the largest automobile air conditioner consuming country in the world (the sales amount accounts for about 24 percent of the total amount in the world), and is the largest country in the world which has not regulated R134 a. The reduction and replacement of the automobile air-conditioning refrigerant R134a not only meets the policy trend and background of energy conservation and emission reduction, but also makes an important contribution to the fulfillment of Montreal agreement by China. Therefore, the search for environment-friendly and efficient alternative refrigerants and related technologies has become an urgent task in the automobile air-conditioning industry in China.

International contracts such as the montreal protocol and the kyoto protocol require that contracting countries gradually reduce and eventually disable refrigerant R134a, and at the same time, impose higher environmental requirements on alternatives thereof, in addition to requiring that new refrigerants have no damaging effect on the ozone layer, also require that new refrigerants have as low GWP values as possible.

In the prior art, a chinese patent document CN200810231909.2 discloses an alkane refrigerant consisting of 80-89% of propane and 11-20% of isobutane; patent US2008029733 discloses refrigerant mixtures consisting of pentafluoroethane, tetrafluoropropane and hydrocarbons; KR200500494148 discloses a mixed refrigerant consisting of 71-90% of propane and 10-29% of 1, 1-difluoroethane; chinese patent document CN200810238072.4 discloses a mixture of 45-52% pentafluoroethane, 45-52% 1,1,1, 2-tetrafluoroethane and 3-6% dimethyl ether; patent CN200810097 discloses a ternary azeotropic mixture composed of 1,1,1, 2-tetrafluoroethane, dimethyl ether and propane; chinese patent CN201010198685.7 discloses a mixture of 2,3,3, 3-tetrafluoropropene, trans 1,3,3, 3-tetrafluoropropene and 1, 1-difluoroethane; chinese patent CN201010196200.0 discloses a mixture of trans-1, 3,3, 3-tetrafluoropropene, difluoromethane and difluoromethane; chinese patent document CN2010196224.6 discloses a mixture consisting of 2,3,3, 3-tetrafluoropropene, difluoromethane and dimethyl ether.

The refrigerants disclosed in the above patents have disadvantages of high GWP values or non-direct can application to R134a systems, or high flammability, and thus, there is a need to develop new refrigerants having better refrigeration performance, better compatibility with existing systems, and better environmental protection performance.

Disclosure of Invention

The invention provides an environment-friendly mixed refrigerant replacing R134a, which does not destroy the atmospheric ozone layer, has thermal parameters and thermal properties equivalent to or even more excellent than R134a, and has lower GWP value.

An environment-friendly mixed refrigerant for replacing R134a is composed of 3,3, 3-trifluoropropene, difluoromethane, 1,1,1, 2-tetrafluoroethane and metal oxide nanoparticles, and comprises the following components in percentage by mole: 29-92% of 3,3, 3-trifluoropropene, 3-20% of difluoromethane, 5-61% of 1,1,1, 2-tetrafluoroethane and 0-0.05% of metal oxide nanoparticles.

The preferable environment-friendly mixed refrigerant for replacing R134a comprises the following components in percentage by mole: 63-90% of 3,3, 3-trifluoropropene, 5-15% of difluoromethane and 5-32% of 1,1,1, 2-tetrafluoroethane.

The preferable environment-friendly mixed refrigerant for replacing R134a comprises the following components in percentage by mole: 29-58% of 3,3, 3-trifluoropropene, 5-15% of difluoromethane and 32-61% of 1,1,1, 2-tetrafluoroethane.

The preferable environment-friendly mixed refrigerant for replacing R134a is characterized in that the mol percentages of the components are as follows: 64-85% of 3,3, 3-trifluoropropene, 5-10% of difluoromethane and 10-26% of 1,1,1, 2-tetrafluoroethane.

The oxidized metal nano-particles are Fe₂O₃、MnO₂ZnO or Al₂O₃。

The preparation method of the environment-friendly mixed refrigerant for replacing R134a comprises the steps of sequentially adding 29-92% of trifluoropropene, 3-20% of difluoromethane, 5-61% of 1,1,1, 2-tetrafluoroethane and 0-0.05% of metal oxide nanoparticles into a stirring kettle body, controlling the temperature of the kettle body to be-0-20 ℃, and physically mixing the trifluoropropene, the difluoromethane, the 1,1,1, 2-tetrafluoroethane and the metal oxide nanoparticles in a liquid phase state to obtain the environment-friendly mixed refrigerant for replacing R134 a.

By adopting the technical scheme, the invention has the beneficial effects that:

(1) the environment-friendly performance is good, the ODP value is 0, and the GWP value is greatly reduced relative to R134 a;

(2) the refrigerant has excellent thermal parameters and thermal performance, and the cycle efficiency, the refrigeration coefficient and the unit volume refrigeration capacity in the refrigeration system are superior to R134a or equivalent to R134 a.

(3) Meanwhile, the refrigerant has the saturated vapor pressure similar to that of R134a, and can directly replace R134a without redesigning a refrigeration system.

(4) The compatibility of the mixed refrigerant with mineral lubricating oil is higher than that of the mixed refrigerant of hydrofluoroolefin and hydrofluorocarbon.

Drawings

Fig. 1 mixes the refrigerant with the saturated vapor profile of R134 a.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

The preparation of the mixed refrigerant was carried out in a 2L stainless steel stirred tank having a cooling function. Setting the temperature of a stirring kettle to be-10 ℃, sequentially adding 278.4g of 3,3, 3-trifluoropropene, 54g of difluoromethane and 6222.2g of 1,1,1, 2-tetrafluoroethane into the kettle, starting a stirrer after filling a sample, cooling to-20 ℃, keeping stirring for 2h, and controlling the pressure of an equilibrium kettle to be within 0.2MPa so as to mix the 3,3, 3-trifluoropropene, the difluoromethane and the 1,1,1, 2-tetrafluoroethane in a liquid phase state. After the treatment process is finished, the mixed refrigerant is obtained, wherein the mol percent of the 3,3, 3-trifluoropropene is 29%, the mol percent of the difluoromethane is 10%, and the mol percent of the 1,1,1, 2-tetrafluoroethane is 61%.

Examples 2 to 10

Examples 2 to 10 methods for preparing the eco-friendly mixed refrigerant were similar to example 1, except that the mole percentages of 3,3, 3-trifluoropropene, difluoromethane and 1,1,1, 2-tetrafluoroethane were changed, and the specific amounts used were as shown in table 1.

TABLE 1

Example 11

The preparation of the mixed refrigerant was carried out in a 2L stainless steel stirred tank having a cooling function. Firstly, 1.60g of nano-particle Fe₂O₃Adding into a balance kettle, and setting the temperature of the stirring kettle at-10 ℃. 625.8g of 3,3, 3-trifluoropropene, 54g of difluoromethane and 224.4g of 1,1,1, 2-tetrafluoroethane are sequentially added into the kettle, after the sample is filled, a stirrer is started, the temperature is reduced to-20 ℃, the stirring is kept for 2h, and the pressure of the balance kettle is controlled within 0.2MPa, so that the 3,3, 3-trifluoropropene, the difluoromethane and the 1,1,1, 2-tetrafluoroethane are mixed in a liquid phase state. After the treatment process is finished, a mixed refrigerant is obtained, wherein the mol percent of 3,3, 3-trifluoropropene is 67.99%, the mol percent of difluoromethane is 10%, the mol percent of 1,1,1, 2-tetrafluoroethane is 22%, and Fe₂O₃The mole percentage of nanoparticles was 0.01%.

Examples 12 to 14

Examples 12 to 14 preparation methods of the eco-friendly mixed refrigerant are similar to example 11, except that Fe₂O₃Change of nanoparticles to MnO₂ZnO or Al₂O₃The specific amounts of nanoparticles used are shown in table 2.

TABLE 2

Examples	Components	Addition amount per gram
			12	MnO₂Nanoparticles	0.88
13	ZnO nanoparticles	0.81
			14	Al₂O₃Nanoparticles	1.12

The performance of the environment-friendly mixed refrigerant used for replacing R134a of the invention is as follows:

the characteristics and effects of the present invention will now be described by comparing the performance of the above embodiment with that of R134 a.

1. Environmental performance

TABLE 3 comparisonThe environmental performance of the above embodiment with R134a was demonstrated. Wherein the ODP value takes CFC-11 as a reference value of 1.0, and the GWP value takes CO₂As a reference value of 1.0(100 years).

Table 3 environmental performance comparison table

As can be seen from Table 3, the above examples have an Ozone Depletion Potential (ODP) value of zero and no damaging effect on the atmospheric ozone layer, which is superior to R134 a.

Moreover, the green house benefit potential (GWP) value of the embodiment is far less than that of R134a, and the embodiment is more in line with the current environmental protection requirements of protecting the ozone layer and reducing the global warming effect.

2. Thermal parameters and thermodynamic properties

Table 4 compares the thermal parameters (evaporation pressure, condensation pressure, pressure ratio, exhaust temperature) and the relative thermal performance (relative volumetric refrigeration capacity, relative COP) of the above examples with R134a under the standard operating conditions of the automotive air conditioner (evaporation temperature 2 ℃, condensation temperature 60 ℃, supercooling degree 5 ℃, superheat degree 5 ℃). The relative thermal performance refers to the ratio of the actual thermal performance to the thermal performance of R134 a.

Table 4 performance comparison table of mixed refrigerant in examples

As can be seen from table 4, under the working conditions of the automotive air conditioner, the condensing pressure, the evaporating pressure, and the pressure ratio of the refrigerant prepared in examples 1 to 10 are similar to those of R134a, and are all within the allowable range, and can directly replace R134a without redesigning the refrigeration system. In addition, the refrigerating capacity per unit volume and the power consumption per unit volume of the refrigerant prepared in the embodiments 1 to 10 are similar to those of R134a, and the relative refrigerating coefficients are both greater than R134a, which indicates that the cycle efficiency of the refrigerating system is improved.

3. Curve of saturated vapor pressure

FIG. 1 shows a comparison of saturated vapor curves for the refrigerants prepared in examples 1-14 and R134 a. (the saturated vapor pressure curve is determined by a static method experimental device, the measurement temperature range is-30-80 ℃, the uncertainty of temperature measurement is 0.02 ℃, and the uncertainty of pressure measurement is 2 kPa.)

As can be seen from fig. 1, the saturated vapor pressure curve of the refrigerant prepared in examples 1 to 14 is very similar to that of R134a, and the refrigerant can be directly filled in a refrigeration system of R134a without changing a compressor.

Claims

1. An environment-friendly mixed refrigerant for replacing R134a, which is characterized in that the molar percentages of the components are as follows: 29-58% of 3,3, 3-trifluoropropene, 5-15% of difluoromethane, 32-61% of 1,1,1, 2-tetrafluoroethane and 0-0.05% of metal oxide nanoparticles, wherein the mole percentage of the metal oxide nanoparticles is different from 0.

2. An environment-friendly mixed refrigerant for replacing R134a, which is characterized in that the molar percentages of the components are as follows: 64-85% of 3,3, 3-trifluoropropene, 5-10% of difluoromethane, 10-26% of 1,1,1, 2-tetrafluoroethane and 0-0.05% of metal oxide nanoparticles, wherein the mole percentage of the metal oxide nanoparticles is different from 0.