CN100347265C - Mixed heat pump work substance with zero ozone layer destroying potential - Google Patents

Abstract

A heat pump mixed working fluid with zero ozone destruction potential relates to a mixed refrigeration working medium used in a medium-high temperature water source heat pump unit. The working fluid contains 1,1,1,2-tetrafluoroethane, 1,1,1,2,3,3,3-heptafluoropropane and 1,1,1,2,3,3-hexafluoropropane substances; butane can also be added to the above three components to form a quaternary mixed working medium. The preparation method is to physically mix the above-mentioned various components according to their corresponding proportions in a liquid state. The invention does not destroy the ozone layer and meets the requirements of environmental protection; it is non-toxic and non-flammable, has good thermal performance and thermal parameters, and can be directly used in HFC-134a heat pump units without modification of the main components of the compressor and the system ; The heat pump unit using the mixed refrigerant can provide medium and high temperature hot water at about 80°C.

Description

Heat pump mixture with zero ozone depletion potential

technical field

The invention relates to a mixed refrigeration working medium used in a medium-high temperature water source heat pump unit, in particular to a heat pump working medium which does not destroy the ozone layer at all (that is, the ozone destruction potential ODP=0).

Background technique

Water source heat pump technology uses geothermal water, groundwater, surface water (river water, lake water, sea water), industrial waste water and other low-temperature and low-level thermal energy resources, and adopts the principle of heat pump to transfer low-level heat energy to high-level heat energy through a small amount of electric energy input, so as to realize power supply. An energy-saving and environmentally friendly technology for heating and cooling. The water source heat pump has the characteristics of high efficiency and energy saving, stable and reliable operation, remarkable environmental benefits, and one machine with multiple functions. Because water source heat pumps have high efficiency, are almost not affected by the ambient temperature in various seasons, and can effectively use waste heat energy, they are currently a major research direction in the refrigeration and air-conditioning industry.

CFC-11 and CFC-114 are the medium and high temperature working fluids usually used in water source heat pumps in the past. However, since both CFC-11 and CFC-114 belong to CFC substances, their ozone depletion potential ODP is 1.0 and 0.85 respectively, which have serious damage to the atmospheric ozone layer, and their greenhouse effect is also very large, and their greenhouse effect potential The values of GWP are 4600 and 9800 respectively. Developed countries have banned it in 1996, while developing countries will also ban it in 2010. Therefore, it is very necessary to develop high-temperature working fluids in water source heat pumps that are environmentally friendly, especially heat pump working fluids that do not destroy the ozone layer (that is, ODP=0) at all.

In order to meet the needs of radiator heating and prevent bacteria (such as Legionella, etc.) from breeding in domestic hot water, it is often necessary to provide hot water at about 80°C.

At present, the existing heat pump working fluid, or the outlet water temperature is too low (Freon-22 and 1,1,1,2-tetrafluoroethane), or has a destructive effect on the atmospheric ozone layer (that is, the ODP is not zero), or the outlet water The temperature is so high that the original compressor cannot work properly. Therefore, there is an urgent need for a heat pump working fluid that does not destroy the ozone layer at all and can use the existing compressor to provide hot water at about 80°C.

Contents of the invention

The invention aims at researching and developing a new mixed working medium suitable for medium and high temperature water source heat pump units, so that it can not only not destroy the ozone layer, but also meet the environmental protection requirements of reducing the greenhouse effect; it also has better thermal parameters and thermal performance, and is safe. , reliable; and compatible with the existing HFC-134a chiller equipment and refrigeration oil, can be directly charged, and can provide medium-high temperature heat of about 80°C under the condition of direct use of medium-temperature water source (about 40°C) water.

Technical scheme of the present invention is as follows:

A heat pump mixed working fluid with zero ozone depletion potential provided by the present invention is characterized in that: the mixed working medium contains 1,1,1,2-tetrafluoroethane, 1,1,1,2,3,3 , 3-heptafluoropropane and 1,1,1,2,3,3-hexafluoropropane, the mass percentages of each component are as follows:

1,1,1,2-Tetrafluoroethane 10～80%

1,1,1,2,3,3,3-Heptafluoropropane 5～80%

1,1,1,2,3,3-hexafluoropropane 15-80%.

Butane can also be added in the above three components, and the mass percent content of its components is respectively:

1,1,1,2-Tetrafluoroethane 10～80%

1,1,1,2,3,3,3-Heptafluoropropane 5～80%

1,1,1,2,3,3-Hexafluoropropane 13～80%

Butane 2～10%

The refrigeration working fluid provided by the invention can be prepared by physically mixing the above-mentioned various components according to their corresponding proportions in a liquid state.

Among the above components, 1,1,1,2-tetrafluoroethane (HFC-134a) has a molecular formula of CH ₂ FCF ₃ , a molar mass of 102.03, a normal boiling point of -26.1°C, and a critical temperature of 101.1°C. The pressure is 4.06MPa.

1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea), its molecular formula is CF ₃ CHFCF ₃ , its molar mass is 170.03, its normal boiling point is -15.6°C, its critical temperature is 102.8°C, and its critical pressure is 2.98MPa.

1,1,1,2,3,3-hexafluoropropane (HFC-236ea), its molecular formula is CHF ₂ CHFCF ₃ , its molar mass is 152.04, its normal boiling point is 6.2°C, its critical temperature is 139.3°C, and its critical pressure is 3.50 MPa.

Butane (HC-600), its molecular formula is CH ₃ CH ₂ CH ₂ CH ₃ , its molar mass is 58.12, its normal boiling point is -0.5°C, its critical temperature is 152.0°C, and its critical pressure is 3.80MPa.

The present invention has the following advantages and beneficial effects:

a.Environmental performance:

The refrigerant of the present invention has zero ozone destruction potential (ODP) and low greenhouse effect coefficient (GWP), which is similar to HFC-134a. The invention fully complies with the environmental protection requirements of protecting the ozone layer and reducing the greenhouse effect.

b. Thermal parameters:

HFC-134a refrigerant under normal temperature heat pump conditions (evaporating temperature 27°C, condensing temperature 71°C, subcooling temperature 5°C and superheating temperature 5°C), the evaporation pressure is 706.2MPa, the condensation pressure is 2168.3MPa, and the compression ratio is 3.07 , The exhaust temperature is 87.9°C. And when the present invention is used in medium and high temperature design conditions (evaporating temperature 40°C, condensation temperature 83°C, supercooling temperature 2°C and superheating temperature 10°C), the evaporation pressure and condensation pressure are all the same as those of HFC-134a in medium and normal temperature heat pump conditions The next one is similar. It shows that the present invention can be directly filled in the original HFC-134a system without changing other components, and can provide a higher outlet water temperature (about 80°C).

c. Thermal performance:

The heating COP of the present invention is about 4.8 and the volumetric heat supply is about 5100kJ/ ^m3 under the above design working conditions, and the thermal performance is better.

In summary, the present invention does not destroy the ozone layer, can reduce the impact of the greenhouse effect, and meets environmental protection requirements; it is non-toxic, non-flammable, has good thermal performance and thermal parameters, and can directly use the HFC-134a heat pump system to provide High-temperature hot water (about 80°C), the main components in the compressor and the system do not need to be changed, and the production line does not need to be modified.

Detailed ways

Example 1: 10% of HFC-134a, 10% of HFC-227ea and 80% of HFC-236ea were physically mixed in liquid phase.

Example 2: 45% of HFC-134a, 25% of HFC-227ea and 30% of HFC-236ea were physically mixed in liquid phase.

Example 3: 80% of HFC-134a, 5% of HFC-227ea and 15% of HFC-236ea were physically mixed in liquid phase.

Example 4: 10% of HFC-134a, 5% of HFC-227ea, 80% of HFC-236ea and 5% of HC-600 were physically mixed in liquid phase.

Example 5: 53% of HFC-134a, 20% of HFC-227ea, 20% of HFC-236ea and 7% of HC-600 were physically mixed in liquid phase.

Example 6: 80% of HFC-134a, 5% of HFC-227ea, 13% of HFC-236ea and 2% of HC-600 were physically mixed in liquid phase.

Under the design working conditions, that is, the evaporation temperature is 40°C, the condensation temperature is 83°C, the subcooling temperature is 2°C, and the superheating temperature is 10°C, the thermal properties of the refrigerants in the above examples are listed in Table 1. Table 1 also lists the parameters of HFC-134a for comparison.

It can be seen from Table 1 that, compared with HFC-134a, the condensing pressure is low, the exhaust temperature is equivalent, and the COP and heat supply under heating conditions are equivalent, indicating that the existing HFC-134a heat pump compressor can be used to form a heat pump unit , Under the condition of medium and normal temperature water source (about 40 ℃), it can provide hot water at about 80 ℃. In addition, it can also be seen from Table 1 that the ODP values of the refrigerants of the present invention are all zero, and the GWP is lower than or similar to HFC-134a. It is worth noting that due to the addition of HC-600, the GWP value of the quaternary refrigerant proposed in this patent is smaller than that of the corresponding ternary refrigerant. Therefore, the overall environmental performance is better.

Table 1 The thermal performance and environmental properties of the examples Example example 1 Example 2 Example 3 Example 4 Example 5 Example 6 HFC134a Evaporating pressurekPa 419.5 728.1 902.8 423.4 795.6 915.8 1018.2 Condensing pressurekPa 1338.4 2129.2 2545.6 1333.6 2255.9 2562.9 2802.4 Pressure ratio 3.19 2.92 2.82 3.15 2.84 2.80 2.75 Exhaust temperature °C 93.3 98.6 102.1 93.6 99.2 101.9 103.2 Heating COP 4.97 4.74 4.69 4.98 4.70 4.67 4.62 Heat supply kJ/kg 130.07 126.15 138.64 139.72 135.98 139.62 142.15 Volume heat supply kJ/m ³ 3250.4 4956.5 5924.9 3256.7 5216.6 5936.0 6470.0 ODP 0 0 0 0 0 0 0 GWP 1104 1586 1317 883 1344 1276 1300

Claims (3)

1. an ozone layer destroying potential is zero heat pump mixed working medium, and wherein the mass percent sum of each constituent element is 100%, it is characterized in that: this mixing medium contains 1,1,1,2-Tetrafluoroethane, 1,1,1,2,3,3,3-heptafluoro-propane and 1,1,1,2,3, three kinds of materials of 3-HFC-236fa, this content of quality percentage of described three kinds of components is respectively:

1,1,1,2-Tetrafluoroethane 10～80%

1,1,1,2,3,3,3-heptafluoro-propane 5～80%

1,1,1,2,3,3-HFC-236fa 20～80%.

2. be zero heat pump mixed working medium according to the described ozone layer destroying potential of claim 1, it is characterized in that: described mixing medium also contains butane, and this content of quality percentage of butane is:

1,1,1,2-Tetrafluoroethane 10～80%

1,1,1,2,3,3,3-heptafluoro-propane 5～80%

1,1,1,2,3,3-HFC-236fa 20～80%

Butane 2～10%.

3. be zero heat pump mixed working medium according to the described a kind of ozone layer destroying potential of claim 1, it is characterized in that: this mixing medium is only by 1,1,1,2-Tetrafluoroethane, 1,1,1,2,3,3,3-heptafluoro-propane and 1,1,1,2,3, three kinds of materials of 3-HFC-236fa are formed, and the mass percentage content of each component is respectively:

1,1,1,2-Tetrafluoroethane 10～80%

1,1,1,2,3,3,3-heptafluoro-propane 5～80%

1,1,1,2,3,3-HFC-236fa 30～80%.