A mixed refrigerant for replacing r290

Abstract

The application belongs to the technical field of refrigeration, heat pump and low-boiling power cycle, and discloses a mixed refrigerant for replacing R290. The mixed refrigerant comprises a first component, a second component and a third component, wherein the first component is hexafluoropropylene (R1216) with a mass ratio of 45% to 70%, the second component is propane (R290) with a mass ratio of 27% to 47%, and the third component is monofluoroethane (R161) with a mass ratio of 3% to 8%. The mixed refrigerant provided by the application is used for replacing R290, has a GWP value of not more than 5, and has obvious advantages in safety in that the flammability is obviously weaker than that of R290. The thermodynamic performance of the mixed refrigerant of the application is equivalent to or even better than that of R290, and the mixed refrigerant can completely replace R290 to be used in refrigeration, heat pump and low-boiling power cycle system, and has wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of refrigeration, heat pump and low boiling point power cycle technology, specifically, it relates to a mixed refrigerant for replacing R290. Background Technology

[0002] Refrigerants have long been a major source of greenhouse gases. With the tightening of global environmental regulations and the gradual emergence of stricter emission control standards, the demand for alternative refrigerants has become increasingly urgent.

[0003] Hydrocarbons are regaining industry attention due to their zero ozone depletion potential (ODP), extremely low global warming potential (GWP), and good thermodynamic cycle performance. Propane (R290), in particular, possesses excellent flowability and heat transfer properties, low exhaust temperature, small charge quantity, and low pressure ratio. It has been used for many years in large-scale refrigeration units in the petrochemical industry, and the U.S. Environmental Protection Agency has conditionally accepted its use as a refrigerant in freezers and retail refrigerators. The next important application for R290 will be as a replacement for R22 in residential air conditioning. However, R290 has a flash point of 468°C and an explosive limit of 2.1%–9.5% (volume fraction). This flammability and explosiveness label is the biggest obstacle to the large-scale promotion and application of R290. Currently, only by solving the flammability and explosiveness issues and eliminating public fears can the widespread application of R290 be truly realized.

[0004] Due to the inherent contradictions between the environmental friendliness, flammability, and thermodynamic properties of the working fluid, pure working fluids often fail to meet current requirements. Mixed working fluids, which can balance the physical properties of the working fluid, have attracted considerable attention. However, a perfect alternative has yet to be found. Overcoming the shortcomings of existing technologies and finding a working fluid with good thermodynamic properties and environmental friendliness to replace R290 has become an urgent problem to be solved. Summary of the Invention

[0005] The present invention aims to solve the technical problem of poor safety performance of R290 refrigerant and provides a mixed refrigerant to replace R290. The mixed refrigerant has a GWP value of less than 5, its flammability is significantly weaker than that of R290, and its thermodynamic performance is comparable to or even better than that of R290. It is suitable for application in the fields of refrigeration, heat pump and low boiling point power cycle.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0007] The present invention provides a mixed refrigerant to replace R290, comprising a first component, a second component and a third component; the first component is hexafluoropropylene (R1216) at a mass ratio of 45% to 70%; the second component is propane (R290) at a mass ratio of 27% to 47%; and the third component is monofluoroethane (R161) at a mass ratio of 3% to 8%.

[0008] Furthermore, the first component accounts for 49% to 66% of the mass, the second component accounts for 30% to 45% of the mass, and the third component accounts for 4% to 6% of the mass.

[0009] Furthermore, its GWP value is less than 5, and its flammability is weaker than R290.

[0010] A method for preparing a mixed refrigerant to replace R290 according to the present invention involves physically mixing the three component substances at room temperature according to their specified mass ratios. Each component in this invention is commercially available or can be prepared by methods known in the art. The basic parameters of each component are shown in Table 1.

[0011] Table 1 Basic physical parameters of each component

[0012]

[0013] The beneficial effects of this invention are:

[0014] (i) The mixed refrigerant provided by this invention for replacing R290 has a global warming potential (GWP) of less than 5, and therefore has outstanding environmental performance.

[0015] (ii) The mixed refrigerant provided by the present invention for replacing R290 contains a large proportion of the non-flammable working substance R1216, which can suppress the flammability of R290 and R161, thereby improving the safety performance of the refrigeration heat pump system.

[0016] (iii) The mixed refrigerant provided by the present invention for replacing R290 has a coefficient of performance and a cooling capacity per unit volume that are comparable to or even better than R290, and has high system cycle performance.

[0017] (iv) The mixed refrigerant provided by the present invention for replacing R290 can be applied to R290 refrigeration, heat pump and low boiling point power cycle systems without the need for many parts replacement, or only some parts modification.

[0018] In summary, the thermodynamic performance of the mixed refrigerant of this invention is comparable to or even better than that of R290, and its flammability is significantly weaker than that of R290, giving it a clear advantage in terms of safety. It can solve the safety problem of the flammability and explosiveness of the environmentally friendly refrigerant R290, and is of great significance for the promotion of R290 refrigerant in refrigeration, heat pump and low boiling point power cycle systems. Detailed Implementation

[0019] The present invention will be further described below through specific embodiments. These embodiments are provided to enable those skilled in the art to better understand the invention and are not intended to limit the scope of the invention.

[0020] The refrigerants hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) used in the following examples are all commonly used refrigerants in the fields of refrigeration, heat pumps, and low-boiling-point power cycle technology. They are physically mixed in different mass ratios under normal temperature and pressure in a liquid phase state, and after homogeneous mixing, a mixed refrigerant is formed to replace R290. Several specific examples are given below, where the proportions of each component are mass ratios, and the sum of the mass ratios of the components in each mixed working fluid is 100%.

[0021] Example 1

[0022] Hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) were physically mixed uniformly in the liquid phase at a mass percentage of 45% / 47% / 8% to obtain a mixed refrigerant to replace R290.

[0023] Example 2

[0024] Hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) were physically mixed uniformly in the liquid phase at a mass percentage of 70% / 27% / 3% to obtain a mixed refrigerant to replace R290.

[0025] Example 3

[0026] Hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) were physically mixed uniformly in the liquid phase at a mass percentage of 64% / 29% / 7% to obtain a mixed refrigerant to replace R290.

[0027] Example 4

[0028] Hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) were physically mixed uniformly in the liquid phase at a mass percentage of 52% / 41% / 7% to obtain a mixed refrigerant to replace R290.

[0029] Example 5

[0030] Hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) were physically mixed uniformly in the liquid phase at a mass percentage of 49% / 45% / 6% to obtain a mixed refrigerant to replace R290.

[0031] Example 6

[0032] Hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) were physically mixed uniformly in the liquid phase at a mass percentage of 66% / 30% / 4% to obtain a mixed refrigerant to replace R290.

[0033] Example 7

[0034] Hexafluoropropylene (R1216), propane (R290), and monofluoroethane (R161) were physically mixed uniformly in the liquid phase at a mass percentage of 56% / 39% / 5% to obtain a mixed refrigerant to replace R290.

[0035] The basic parameters, such as the environmental performance and temperature glide (at standard atmospheric pressure of 101.325 kPa) of the above embodiments and R290 working fluid, are recorded in Table 2.

[0036] The molar mass (g / mol), standard boiling point (°C), critical temperature (°C), and critical pressure (MPa) were obtained from REFPROP 10.0a, a working fluid property lookup tool developed by the National Institute of Standards and Technology (NIST).

[0037] The temperature glide (°C) was calculated using REFPROP 10.0a software via Matlab.

[0038] GWP data comes from the Intergovernmental Panel on Climate Change (IPCC) report, "Climate Change 2021: The Physical Science Basis".

[0039] Table 2 Comparison of basic physical properties of Examples 1-7 and R290

[0040]

[0041] As shown in Table 2, the GWP values ​​of the mixed refrigerant provided by the present invention for replacing R290 are all less than 5, which has excellent environmental performance and meets the requirements of current international laws and regulations. The bubble point temperature of each embodiment is close to the standard boiling point of R290. The temperature glide of each embodiment is small, and some embodiments (Example 1, Example 4, Example 5 and Example 7) are close to azeotropic refrigerants, which can reduce the adverse effects caused by the temperature glide of the working fluid during system operation.

[0042] Table 3 shows the comparison results of the thermodynamic parameters (discharge pressure and temperature) and relative system cycle performance (relative volumetric cooling capacity and relative COP of each embodiment relative to R290) of the above embodiments with R290 under the refrigeration conditions of evaporation temperature of 5℃, condensation temperature of 40℃, superheat of 10℃, subcooling of 5℃, and compressor overall efficiency of 0.8.

[0043] Table 3 Comparison of Cyclic Performance of Examples 1-7 and R290

[0044]

[0045] The evaporation pressure (MPa), condensation pressure (MPa), pressure ratio, exhaust temperature (°C), relative unit volume refrigeration capacity, and relative COP data are calculated based on a single-stage compression steam refrigeration cycle.

[0046] Table 3 shows that: 1. The volumetric cooling capacity of the mixed refrigerants obtained in each embodiment is slightly higher than that of R290, and the system performance coefficient (COP) of the mixed refrigerants is also very close to that of R290, indicating the feasibility of the mixed refrigerants as a substitute in terms of cycle performance; 2. The results also show that the evaporation pressure and condensation pressure of the mixed refrigerants obtained in most embodiments are not much different from those of R290, and the pressure ratio of the mixed refrigerants obtained in some embodiments is even smaller, which helps to improve the efficiency of the compressor; 3. As a substitute for R290, the discharge temperature of the mixed refrigerants obtained in each embodiment is lower, and the discharge temperature of the compressors in the above embodiments has been reduced; 4. R1216 is a highly efficient flame retardant, so it can be predicted that the proportion of the mixture contained in the mixed refrigerant is mainly non-flammable or weakly flammable refrigerant, which increases the safety of system operation and working environment;

[0047] As can be seen, under the above operating conditions and within the preferred ratio range calculated theoretically, the system cycle performance of the mixed refrigerant of the present invention for replacing R290 is close to or even better than that of R290. Its outstanding advantage is that the mixed refrigerant can achieve a non-flammable or weakly flammable effect, exhibiting significant safety performance advantages compared to R290 refrigerant. In summary, the mixed refrigerant provided by the present invention has excellent application effects and development potential in replacing R290.

[0048] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art, under the guidance of the present invention, can make many specific modifications without departing from the spirit and scope of the claims, and these modifications all fall within the scope of protection of the present invention.

Claims

1. A mixed refrigerant for replacing R290, comprising a first component, a second component, and a third component; characterized in that, The first component is hexafluoropropylene (R1216) at a mass ratio of 49% to 70%; the second component is propane (R290) at a mass ratio of 27% to 47%; and the third component is monofluoroethane (R161) at a mass ratio of 3% to 8%.

2. A mixed refrigerant for replacing R290 according to claim 1, characterized in that, The first component accounts for 49% to 66% of the mass, the second component accounts for 30% to 45% of the mass, and the third component accounts for 4% to 6% of the mass.

3. A mixed refrigerant for replacing R290 according to claim 1, characterized in that, Its GWP value is less than 5, and its flammability is weaker than R290.

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