CN116272748B - System and method for supercritical thermal degradation of refrigerants - Google Patents

Abstract

The invention discloses a system and method for supercritical thermal degradation of refrigerant. The system includes: a refrigerant boosting device, an oxidant boosting device, a preheater and a supercritical reactor. The refrigerant boosting device has a refrigerant inlet and a high-pressure refrigerant outlet; the oxidant boosting device has an oxidant inlet. and a high-pressure oxidant outlet; the preheater includes a refrigerant heat exchange channel and an oxidant heat exchange channel. The refrigerant heat exchange channel has a high-pressure refrigerant inlet and a high-pressure refrigerant outlet. The high-pressure refrigerant inlet is connected to the high-pressure refrigerant outlet. The refrigerant outlet is connected, and the oxidant heat exchange channel has a high-pressure oxidant inlet and a high-temperature oxidant outlet, and the high-pressure oxidant inlet is connected to the high-pressure oxidant outlet. The supercritical thermal degradation refrigerant system of the present invention utilizes the high reactivity and good mass transfer performance of the refrigerant in the supercritical fluid state to achieve effective degradation of the refrigerant under low temperature conditions.

Description

Systems and methods for supercritical thermal degradation of refrigerants

Technical field

The present invention relates to the technical field of refrigerant treatment, and in particular to a system and method for supercritical thermal degradation of refrigerant.

Background technique

The construction of human production civilization is inseparable from the widespread application of refrigeration and air-conditioning technology. The core of refrigeration technology lies in the development of refrigerants. At present, refrigerants have experienced four generations of development, including perchlorofluorocarbons (CFCs) substances, hydrochlorofluorocarbons (HCFCs) substances, hydrofluorocarbons (HFCs) substances and hydrofluoroolefins (HFOs) substances. . At present, my country is the world's largest producer and consumer of HCFCs refrigerants and HFCs refrigerants. The annual production of these two types of refrigerants accounts for approximately 90% and 84% of the world's total. In order to avoid the destructive effect of refrigerants on the ozone layer and their impact on global warming, according to the Kigali Amendment to the Montreal Protocol (officially effective on January 1, 2019), my country has reduced and eliminated HCFCs and HFCs refrigerants. Already on the agenda.

Our country has a large need for refrigerant destruction, but the refrigerant destruction technology is not yet mature. Previous refrigerant recovery and treatment technologies were mostly based on purification, so as to obtain relatively high-purity refrigerants for recycling. In related technologies, there are methods suitable for separating refrigerant and lubricating oil, so that the refrigerant can be purified and recycled for secondary use. There are also methods that use the different boiling points of the components in the mixed refrigerant to use multi-stage heat exchange components. A method of separating mixed components to obtain high-purity refrigerant, which can then be recycled.

With the gradual elimination of HCFCs and HFCs refrigerants, the processing requirements of these two types of refrigerants are not only recycling, but also further degradation processing to meet environmental protection needs. In the next few decades, our country will face huge pressure on refrigerant degradation. Among the related technologies, there is a method of high-temperature sintering treatment of CFCs material and cement raw material mixing system. The mass proportions of fluorine and chlorine elements in the system are less than 0.04% and 0.5% of the total weight of CFCs refrigerant and cement raw material, and the sintering treatment The temperature is 1400~1600℃. The existing refrigerant treatment method is high-temperature pyrolysis, which consumes high energy and costs, which is contrary to my country's original intention of energy conservation, emission reduction, low-carbon and environmental protection. Therefore, the current refrigerant degradation treatment technology still needs to be improved.

Contents of the invention

The present invention aims to solve one of the technical problems in the related art, at least to a certain extent. To this end, one object of the present invention is to propose a system and method for supercritical thermal degradation of refrigerant. The system of supercritical thermal degradation of refrigerant utilizes the high reactivity and good mass transfer of the refrigerant in the supercritical fluid state. performance, achieving effective degradation of refrigerant under low temperature conditions.

In a first aspect of the invention, the invention proposes a system for supercritical thermal degradation of refrigerant. According to an embodiment of the present invention, the system includes: a refrigerant pressurizing device having a refrigerant inlet and a high-pressure refrigerant outlet; an oxidant pressurizing device having an oxidant inlet and a high-pressure refrigerant outlet. Oxidant outlet; preheater, the preheater includes a refrigerant heat exchange channel and an oxidant heat exchange channel, the refrigerant heat exchange channel has a high-pressure refrigerant inlet and a high-temperature refrigerant outlet, and the high-pressure refrigerant inlet is connected to the oxidant heat exchange channel. The high-pressure refrigerant outlet is connected, the oxidant heat exchange channel has a high-pressure oxidant inlet and a high-temperature oxidant outlet, the high-pressure oxidant inlet is connected to the high-pressure oxidant outlet; a supercritical reactor, the supercritical reactor has a raw material inlet and a high-pressure oxidant outlet. The first exhaust gas outlet, the raw material inlet is connected to the high-temperature refrigerant outlet and the high-temperature oxidant outlet respectively.

According to the supercritical thermal degradation refrigerant system of the above embodiments of the present invention, the refrigerant is pressurized by the refrigerant supercharging device and then supplied to the refrigerant heat exchange channel in the preheater for heating, and the oxidant is pressurized by the oxidant supercharging device. Then, it is supplied to the oxidant heat exchange channel in the preheater for heating. The heated refrigerant and oxidant enter the supercritical reactor from the raw material inlet, so that the refrigerant undergoes thermal degradation in the supercritical state to generate tail gas. The generated tail gas is passed through the third A tail gas outlet is discharged, and in the supercritical reactor, the refrigerant is in a supercritical state. It not only has high reactivity and good mass transfer performance, and can be effectively degraded under low temperature conditions, but also has high density, high solubility and strong With convection and diffusion capabilities, the volume of refrigerant of the same mass is smaller, which can improve the processing capacity of the refrigerant, achieve high concentration, large flow, and rapid decomposition of the refrigerant, thereby achieving low temperature, low energy consumption, and large flow rate of the refrigerant. , effective degradation under conditions of high rate and high refrigerant component ratio. In addition, the refrigerant is heated through the refrigerant heat exchange channel, and the oxidant is heated through the oxidant heat exchange channel. The respectively heated refrigerant and oxidant enter the supercritical reactor from the raw material inlet for degradation, which can avoid mixing the refrigerant and oxidant. Prolonged heating may cause the production of toner and clogging.

In addition, the supercritical thermal degradation refrigerant system according to the above embodiments of the present invention may also have the following additional technical features:

In some embodiments of the invention, the supercritical reactor includes a heater and/or a temperature controller, and/or the preheater includes a heater and/or a temperature controller.

In some embodiments of the present invention, pressure gauges are provided independently at the raw material inlet and the first exhaust gas outlet.

In some embodiments of the invention, the first exhaust gas outlet is connected to a back pressure valve.

In some embodiments of the present invention, a one-way valve is provided between the high-pressure oxidant outlet and the high-pressure oxidant inlet.

In some embodiments of the present invention, a safety valve is provided between the high-pressure oxidant outlet and the high-pressure oxidant inlet and/or at the raw material inlet.

In some embodiments of the present invention, the refrigerant boosting device includes a first liquid pump and a first flow meter, the first liquid pump is connected to the first flow meter, and the first liquid pump is provided with There is the refrigerant inlet, and the high-pressure refrigerant outlet is provided on the first flow meter.

In some embodiments of the present invention, the refrigerant pressurizing device further includes a refrigerant storage container. A refrigerant pre-pressurizing unit is provided in the refrigerant storage container. The refrigerant storage container is connected to the refrigerant. The entrance is connected.

In some embodiments of the present invention, the oxidant boosting device includes an oxidant boosting pump and a second flow meter, the oxidant boosting pump is connected to the second flow meter, and the oxidant boosting pump is provided with The oxidant inlet and the high-pressure oxidant outlet are provided on the second flow meter.

In some embodiments of the present invention, the oxidant boosting device further includes a buffer tank and a pressure reducing valve, the oxidant boosting pump is connected to the buffer tank, and the buffer tank is connected to the buffer tank through the pressure reducing valve. A second flow meter is connected.

In some embodiments of the present invention, the system for supercritical thermal degradation of refrigerant further includes: a hydrogen-containing compound pressurizing device, the hydrogen-containing compound pressurizing device has a hydrogen-containing compound inlet and a high-pressure hydrogen-containing compound outlet; The preheater also includes a hydrogen-containing compound heat exchange channel. The hydrogen-containing compound heat exchange channel has a high-pressure hydrogen-containing compound inlet and a high-temperature hydrogen-containing compound outlet. The high-pressure hydrogen-containing compound inlet is connected to the high-pressure hydrogen-containing compound outlet. , the raw material inlet is connected with the high-temperature hydrogen-containing compound outlet.

In some embodiments of the present invention, the raw material inlet is connected to the high-temperature refrigerant outlet, the high-temperature oxidant outlet, and the high-temperature hydrogen-containing compound outlet respectively through insulated tubes.

In some embodiments of the present invention, the hydrogen-containing compound pressurizing device includes a second liquid pump and a third flow meter, the second liquid pump is connected to the third flow meter, and the second liquid pump The hydrogen-containing compound inlet is provided, and the third flow meter is provided with the high-pressure hydrogen-containing compound outlet.

In some embodiments of the present invention, the system for supercritical thermal degradation of refrigerant further includes: an exhaust gas treatment device having an exhaust gas inlet and a second exhaust gas outlet, and the exhaust gas inlet is connected to the first exhaust gas The outlets are connected, and the second exhaust gas outlet is connected to the back pressure valve.

In some embodiments of the present invention, the exhaust gas treatment device includes a condenser and a filter. The condenser has the exhaust gas inlet and a low-temperature gas outlet. The low-temperature gas outlet is connected to the filter. The filter The appliance has said second exhaust gas outlet.

In some embodiments of the present invention, the exhaust gas treatment device further includes a constant temperature oil bath, and the condenser also has a cooling medium inlet and a cooling medium outlet, and the cooling medium inlet and the cooling medium outlet are respectively connected with the constant temperature oil bath. Oil bath connected.

In some embodiments of the present invention, a catalyst is provided in the supercritical reactor.

In some embodiments of the invention, the catalyst includes at least one of a metal, a metal oxide, and a metal phosphate.

In a second aspect of the present invention, the present invention proposes a method for systematically degrading refrigerant using the supercritical thermally degraded refrigerant of the above embodiment. According to an embodiment of the invention, the method includes:

(1) Use a refrigerant booster device to pressurize the refrigerant, and an oxidant booster device to pressurize the oxidant;

(2) Use a preheater to heat the pressurized refrigerant and the oxidant respectively;

(3) Send the heated refrigerant and oxidant into a supercritical reactor, control the pressure in the supercritical reactor to not be lower than the critical pressure of the refrigerant, and control the supercritical reactor The temperature inside is not lower than the critical temperature of the refrigerant, so that the refrigerant degrades in the supercritical state.

According to the method for degrading refrigerant in the above embodiments of the present invention, a refrigerant pressurizing device is used to pressurize the refrigerant, and an oxidant pressurizing device is used to pressurize the oxidant, so that the pressures of the refrigerant and the oxidant are not lower than those of the refrigerant. critical pressure, using a preheater to heat the pressurized refrigerant and oxidant respectively, so that the temperature of the refrigerant and oxidant is not lower than the critical temperature of the refrigerant, and the heated refrigerant and oxidant are sent to the supercritical Reactor, control the pressure in the supercritical reactor to not be lower than the critical pressure of the refrigerant, and control the temperature in the supercritical reactor to not be lower than the critical temperature of the refrigerant, which can cause the refrigerant to undergo thermal degradation in the supercritical state. tail gas, and in the supercritical reactor, the refrigerant is in a supercritical state. It not only has high reactivity and good mass transfer performance, and can be effectively degraded under low temperature conditions, but also has high density, high solubility and strong convection and diffusion capabilities. , the volume of refrigerant of the same quality is smaller, which can improve the processing capacity of refrigerant, achieve high concentration, large flow, and rapid decomposition of refrigerant, thereby realizing the refrigerant at low temperature, low energy consumption, large flow, and high speed. , effective degradation under conditions of high refrigerant component ratio. In addition, a preheater is used to heat the pressurized refrigerant and oxidant respectively, and the heated refrigerant and oxidant are sent to the supercritical reactor for degradation, which can avoid the problem caused by mixing the refrigerant and oxidant and then heating it for a long time. Produce toner and cause clogging problems.

In addition, the method for degrading refrigerant according to the above embodiments of the present invention may also have the following additional technical features:

In some embodiments of the present invention, step (2) further includes using a preheater to heat the pressurized hydrogen-containing compound; step (3) further includes sending the heated hydrogen-containing compound into the ultrasonic critical reactor.

In some embodiments of the present invention, before step (1), the system of the supercritical thermally degraded refrigerant is tested for tightness.

In some embodiments of the present invention, before step (1), a catalyst is loaded in the supercritical reactor.

In some embodiments of the invention, the refrigerant includes at least one of perchlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons and hydrofluoroolefins.

In some embodiments of the invention, the oxidizing agent includes O ₂ and/or H ₂ O ₂ .

In some embodiments of the invention, the hydrogen-containing compound includes at least one of H ₂ O, CH ₃ OH, and CH ₃ CH ₂ OH.

In some embodiments of the present invention, the method for degrading refrigerants using the supercritical thermally degraded refrigerant system of the above embodiments further includes: (4) cooling the tail gas generated by the degradation of the refrigerant in the supercritical state and /or purification.

In some embodiments of the present invention, the temperature in the supercritical reactor is not higher than 600°C, and the pressure in the supercritical reactor is not higher than 20MPa.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

Figure 1 is a schematic structural diagram of a system for supercritical thermal degradation of refrigerant according to an embodiment of the present invention.

Reference signs: 10. Refrigerant booster device, 11. Refrigerant inlet, 12. High-pressure refrigerant outlet, 13. First liquid pump, 14. First flow meter, 15. Refrigerant storage container, 20. Oxidant booster Pressure device, 21. Oxidant inlet, 22. High-pressure oxidant outlet, 23. Oxidant booster pump, 24. Second flow meter, 25. Buffer tank, 26. Pressure reducing valve, 30. Preheater, 31. Refrigerant changer Hot channel, 311. High-pressure refrigerant inlet, 312. High-temperature refrigerant outlet, 32. Oxidant heat exchange channel, 321. High-pressure oxidant inlet, 322. High-temperature oxidant outlet, 33. Hydrogen-containing compound heat exchange channel, 331. High-pressure hydrogen-containing compound Compound inlet, 332. High-temperature hydrogen-containing compound outlet, 40. Supercritical reactor, 41. Raw material inlet, 42. First tail gas outlet, 43. Pressure gauge, 44. Insulated tube, 50. Back pressure valve, 60. One-way Valve, 70. Safety valve, 80. Hydrogen-containing compound pressurizing device, 81. Hydrogen-containing compound inlet, 82. High-pressure hydrogen-containing compound outlet, 83. Second liquid pump, 84. Third flow meter, 90. Exhaust gas treatment device , 91. Exhaust gas inlet, 92. Second exhaust gas outlet, 93. Condenser, 931. Low-temperature gas outlet, 932. Cooling medium inlet, 933. Cooling medium outlet, 94. Filter, 95. Constant temperature oil bath.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axis" The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply the device or device referred to. Elements must have a specific orientation, be constructed and operate in a specific orientation and therefore are not to be construed as limitations of the invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

In the present invention, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated into one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interactive relationship between two elements, unless otherwise specified limitations. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise expressly stated and limited, a first feature being "on" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. touch. Furthermore, the terms "above", "above" and "above" the first feature is above the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "below" and "beneath" the first feature to the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature has a smaller horizontal height than the second feature.

In a first aspect of the invention, the invention proposes a system for supercritical thermal degradation of refrigerant. According to an embodiment of the present invention, referring to FIG. 1 , the system includes: a refrigerant boosting device 10 , an oxidant boosting device 20 , a preheater 30 and a supercritical reactor 40 . The refrigerant boosting device 10 has a refrigerant inlet 11 and a high-pressure refrigerant outlet 12; the oxidant boosting device 20 has an oxidant inlet 21 and a high-pressure oxidant outlet 22; the preheater 30 includes a refrigerant heat exchange channel 31 and an oxidant heat exchange channel 32, and the refrigerant heat exchange channel 31 has a high-pressure refrigerant Inlet 311 and high-temperature refrigerant outlet 312. The high-pressure refrigerant inlet 311 is connected to the high-pressure refrigerant outlet 12. The oxidant heat exchange channel 32 has a high-pressure oxidant inlet 321 and a high-temperature oxidant outlet 322. The high-pressure oxidant inlet 321 is connected to the high-pressure oxidant outlet 22; ultra The critical reactor 40 has a raw material inlet 41 and a first tail gas outlet 42. The raw material inlet 41 is connected to the high-temperature refrigerant outlet 312 and the high-temperature oxidant outlet 322 respectively.

According to the supercritical thermal degradation refrigerant system of the above embodiment of the present invention, the refrigerant is pressurized by the refrigerant boosting device 10 and then supplied to the refrigerant heat exchange channel 31 in the preheater 30 for heating, and the oxidant is pressurized through the oxidant The device 20 is pressurized and supplied to the oxidant heat exchange channel 32 in the preheater 30 for heating. The heated refrigerant and oxidant enter the supercritical reactor 40 through the raw material inlet 41, so that the refrigerant undergoes thermal degradation in the supercritical state. The tail gas is generated, and the generated tail gas is discharged from the first tail gas outlet 42, and in the supercritical reactor 40, the refrigerant is in a supercritical state, which not only has high reactivity and good mass transfer performance, but can be effectively degraded under low temperature conditions. , also has high density, high solubility and strong convection and diffusion capabilities. The volume of the same mass of refrigerant is smaller, which can improve the processing capacity of the refrigerant, achieve high concentration, large flow, and rapid decomposition of the refrigerant, thereby achieving Effective degradation of refrigerant under the conditions of low temperature, low energy consumption, large flow, high speed and high refrigerant component ratio. In addition, the refrigerant is heated through the refrigerant heat exchange channel 31, and the oxidant is heated through the oxidant heat exchange channel 32. The respectively heated refrigerant and oxidant enter the supercritical reactor 40 through the raw material inlet 41 for degradation, which can avoid the refrigerant and the oxidant. Mixing the oxidant and then heating it for a long time will produce carbon powder and cause clogging.

In embodiments of the present invention, the above-mentioned refrigerants include perchlorofluorocarbons (such as CCl ₃ F), hydrochlorofluorocarbons (such as CHClF ₂ ), hydrofluorocarbons (such as C ₂ H ₂ F ₄ ) and hydrofluoroolefins (such as C ₃ H ₂ F ₄ ).

According to some specific embodiments of the present invention, the refrigerant boosting device 10 can be used to make the pressure of the refrigerant reach above its critical pressure. The refrigerant boosting device 10 can include a first liquid pump 13 and a first flow meter 14. The liquid pump 13 is adapted to pressurize the refrigerant and supply it to the preheater 30. The first liquid pump 13 is connected to the first flow meter 14. The first liquid pump 13 is provided with a refrigerant inlet 11. The first flow meter 14 is Provided with the high-pressure refrigerant outlet 12, the first flow meter 14 may have a first regulating valve (not shown), and the first regulating valve may regulate the flow rate of the refrigerant. Thereby, the refrigerant can be pressurized by the first liquid pump 13 to or above the critical pressure of the refrigerant, and the flow rate of the refrigerant can be controlled by the first flow meter 14 . It should be noted that the type of the first liquid pump 13 is not particularly limited, and those skilled in the art can select it according to actual needs. As a specific example, the first liquid pump 13 may be a liquid booster pump with a liquid delivery function.

According to some further specific embodiments of the present invention, the refrigerant pressurizing device 10 may further include a refrigerant storage container 15. A refrigerant pre-pressurizing unit (not shown) is disposed inside the refrigerant storage container 15. The refrigerant storage container 15 Connected to the refrigerant inlet 11. As a result, the refrigerant in the refrigerant storage container 15 can be pressurized by the refrigerant pre-pressurizing unit to avoid adverse effects on the life of the first liquid pump 13 after the refrigerant vaporizes. It should be noted that the type of refrigerant pre-pressurization unit is not particularly limited, and those skilled in the art can select according to actual needs. As a specific example, the refrigerant pre-pressurization unit may include an air bag, and the air bag is supplied to the air bag through a pneumatic pump. The air bag is inflated, thereby pressurizing the refrigerant in the refrigerant storage container 15 .

According to some specific embodiments of the present invention, the oxidant boosting device 20 can be used to make the pressure of the oxidant reach above the critical pressure of the refrigerant. The oxidant boosting device 20 can include an oxidant boosting pump 23 and a second flow meter 24. The pressure pump 23 is connected to the second flow meter 24. The oxidant boosting pump 23 is provided with an oxidant inlet 21, and the second flow meter 24 is provided with a high-pressure oxidant outlet 22. The second flow meter 24 may have a second regulating valve (not shown). out), the second regulating valve can adjust the flow of oxidant. Thereby, the oxidant can be pressurized by the oxidant boosting pump 23 to or above the critical pressure of the refrigerant, and the flow rate of the oxidant can be controlled by the second flow meter 24 . It should be noted that the types of the oxidant and the oxidant boosting pump 23 are not particularly limited, and those skilled in the art can select them according to actual needs. For example, the oxidant may include O ₂ and/or H ₂ O ₂ . For gaseous oxidants, a gas booster pump may be used; for liquid oxidants, a liquid booster pump may be used. Further, for gaseous oxidants, the oxidant boosting device 20 may also include a buffer tank 25 and a pressure reducing valve 26. The oxidant boosting pump 23 is connected to the buffer tank 25, and the buffer tank 25 is connected to the second flow meter through the pressure reducing valve 26. 24 connected. In this way, the oxidant can be pressurized and stabilized, so that the oxidant can enter the supercritical reactor 40 stably.

According to some specific embodiments of the present invention, the supercritical reactor 40 may include a heater (not shown) and/or a temperature controller (not shown), and the heater may be used to heat the temperature within the supercritical reactor 40 When the temperature reaches above the critical temperature of the refrigerant, a temperature controller can be used to control the stability of the temperature field in the supercritical reactor 40 . Specifically, the temperature controller can have a temperature sensing element (such as a thermocouple or a temperature sensor, etc.), and can detect the temperature in the supercritical reactor 40 through the temperature sensing element. The temperature controller can be connected to the heater. When the supercritical reactor When the temperature within 40°C reaches the temperature value preset by the temperature controller, the temperature controller can stop the heater. Similarly, the preheater 30 may also include a heater and/or a temperature controller. The heater may be used to heat the material entering the preheater 30 to above the critical temperature of the refrigerant. The temperature controller may be used to control the preheater 30. Stability of the internal temperature field. Specifically, the temperature controller can have a temperature sensing element (such as a thermocouple or a temperature sensor, etc.), and can detect the temperature in the preheater 30 through the temperature sensing element. The temperature controller can be connected to the heater. When the temperature in the preheater 30 When the temperature reaches the temperature value preset by the temperature controller, the temperature controller can stop the heater. It should be noted that the type of heater and temperature controller are not particularly limited, and those skilled in the art can choose according to actual needs. As a specific example, an electric heater and a PID temperature controller can be used.

According to some specific embodiments of the present invention, a catalyst may also be provided in the supercritical reactor, and the catalyst is suitable for catalyzing the degradation of the refrigerant. This can increase the rate of refrigerant degradation. It should be noted that the type of catalyst is not particularly limited, and those skilled in the art can select it according to actual needs. For example, it can include metals (such as Pt, Pb), metal oxides (such as Al ₂ O ₃ , MgO) and metal catalysts. At least one of phosphates (such as AlPO ₄ , Mg ₃ (PO ₄ ) ₂ ).

According to some specific embodiments of the present invention, pressure gauges 43 may be independently provided at the raw material inlet 41 and the first exhaust gas outlet 42 . Therefore, the pressure change of the supercritical reactor 40 can be observed through the pressure gauge 43 . Further, the first exhaust gas outlet 42 may be connected to the back pressure valve 50 . Thus, the total pressure of the system of supercritical thermally degraded refrigerant can be controlled through the back pressure valve 50 .

According to some specific embodiments of the present invention, for gaseous oxidant, a one-way valve 60 may be provided between the high-pressure oxidant outlet 22 and the high-pressure oxidant inlet 321 . The oxidant flowing out from the high-pressure oxidant outlet 22 can flow into the oxidant heat exchange channel 32 through the high-pressure oxidant inlet 321 through the one-way valve 60, thereby preventing the oxidant from flowing back. Further, a safety valve 70 may be provided between the high-pressure oxidant outlet 22 and the high-pressure oxidant inlet 321 and/or at the raw material inlet 41 . This protects the system of supercritical thermal degradation of refrigerant.

According to some specific embodiments of the present invention, the system for supercritical thermal degradation of refrigerant may also include: a hydrogen-containing compound supercharging device 80 , which can be used to make the pressure of the hydrogen-containing compound reach the critical pressure of the refrigerant. As mentioned above, the hydrogen-containing compound pressurizing device 80 has the hydrogen-containing compound inlet 81 and the high-pressure hydrogen-containing compound outlet 82 . Therefore, the hydrogen-containing compound supercharging device 80 can be used to provide hydrogen element for the degradation system of the refrigerant with insufficient hydrogen, so that the refrigerant can be thermally decomposed in a supercritical state with an oxidant and a hydrogen-containing compound. It should be noted that the type of hydrogen-containing compound is not particularly limited, and those skilled in the art can select according to actual needs. For example, at least one of H ₂ O, CH ₃ OH, and CH ₃ CH ₂ OH can be used. Further, the hydrogen-containing compound pressurizing device 80 may include a second liquid pump 83 and a third flow meter 84. The second liquid pump 83 is adapted to pressurize and supply the hydrogen-containing compound to the preheater 30. The second liquid pump 83 Connected to the third flow meter 84, the second liquid pump 83 is provided with a hydrogen-containing compound inlet 81, and the third flow meter 84 is provided with a high-pressure hydrogen-containing compound outlet 82. The third flow meter 84 may have a third regulating valve (not shown). shown), the third regulating valve can regulate the flow rate of the hydrogen-containing compound. Thereby, the hydrogen-containing compound can be pressurized to or above the critical pressure of the refrigerant by the second liquid pump 83 , and the flow rate of the hydrogen-containing compound can be controlled by the third flow meter 84 . It should be noted that the type of the second liquid pump 83 is not particularly limited, and those skilled in the art can select it according to actual needs. As a specific example, the second liquid pump 83 may be a liquid booster pump with a liquid delivery function.

According to some specific embodiments of the present invention, the preheater 30 may also include a hydrogen-containing compound heat exchange channel 33. The hydrogen-containing compound heat exchange channel 33 has a high-pressure hydrogen-containing compound inlet 331 and a high-temperature hydrogen-containing compound outlet 332. The compound inlet 331 is connected to the high-pressure hydrogen-containing compound outlet 82, and the raw material inlet 41 is connected to the high-temperature hydrogen-containing compound outlet 332. This allows the hydrogen-containing compound to be heated to a temperature higher than the critical temperature of the refrigerant.

According to some specific embodiments of the present invention, the raw material inlet 41 can be connected to the high-temperature refrigerant outlet 312, the high-temperature oxidant outlet 322, and the high-temperature hydrogen-containing compound outlet 332 through the insulated pipe 44, respectively. Thus, the heat loss of the system in which supercritical thermally degraded refrigerant can be reduced. Further, the insulated pipe 44 may include a main pipe and three parallel branch pipes connected to the main pipe. The raw material inlet 41 is connected to the three parallel branch pipes through the main pipe. The three parallel branch pipes are respectively connected to the high-temperature refrigerant outlet 312 and the high-temperature oxidant outlet 322. , the high-temperature hydrogen-containing compound outlet 332 is connected, thereby fully mixing the refrigerant, the oxidant and the hydrogen-containing compound, which is beneficial to the efficient degradation of the refrigerant.

According to some specific embodiments of the present invention, the system of supercritical thermal degradation refrigerant may also include: an exhaust gas treatment device 90. The exhaust gas treatment device 90 has an exhaust gas inlet 91 and a second exhaust gas outlet 92. The exhaust gas inlet 91 and the first exhaust gas outlet 42 is connected to the second exhaust gas outlet 92 and the back pressure valve 50 is connected. In this way, the exhaust gas (such as CO ₂ , HF, HCl, etc.) generated by the degradation of the refrigerant in the supercritical state can be post-processed.

According to further specific embodiments of the present invention, the exhaust gas treatment device 90 may include a condenser 93 and a filter 94. The condenser 93 has an exhaust gas inlet 91 and a low-temperature gas outlet 931. The low-temperature gas outlet 931 is connected to the filter 94. The filter 94 It has a second exhaust gas outlet 92. In this way, the exhaust gas generated by the degradation of the refrigerant in the supercritical state can be cooled and the ash can be filtered out, so that the back pressure valve 50 can work safely within the temperature-resistant range for a long time, improving system operation stability and extending system life.

According to some specific embodiments of the present invention, the exhaust gas treatment device 90 further includes a constant temperature oil bath 95. The constant temperature oil bath 95 has a constant temperature oil inlet and a constant temperature oil outlet. The condenser 93 also has a cooling medium inlet 932 and a cooling medium outlet 933. The medium inlet 932 is connected to the constant temperature oil outlet, and the cooling medium outlet 933 is connected to the constant temperature oil inlet. Thus, an external circulation can be formed to provide cooling medium for the condenser 93 . Further, the temperature range of the constant temperature oil bath 95 may be room temperature ~ 150°C.

In a second aspect of the present invention, the present invention proposes a method for systematically degrading refrigerant using the supercritical thermally degraded refrigerant of the above embodiment. According to an embodiment of the invention, the method includes:

(1) Use the refrigerant pressurizing device 10 to pressurize the refrigerant, and use the oxidant pressurizing device 20 to pressurize the oxidant;

(2) Use the preheater 30 to heat the pressurized refrigerant and oxidant respectively;

(3) Send the heated refrigerant and oxidant into the supercritical reactor 40, control the pressure in the supercritical reactor 40 to not be lower than the critical pressure of the refrigerant, and control the temperature in the supercritical reactor 40 to not be lower than the refrigeration The critical temperature of the refrigerant is so that the refrigerant degrades in the supercritical state.

According to the method for degrading refrigerant in the above embodiment of the present invention, the refrigerant pressurizing device 10 is used to pressurize the refrigerant, and the oxidant pressurizing device 20 is used to pressurize the oxidant, so that the pressures of the refrigerant and the oxidant can be no less than The critical pressure of the refrigerant, using the preheater 30 to heat the pressurized refrigerant and oxidant respectively, can make the temperature of the refrigerant and oxidant not lower than the critical temperature of the refrigerant, and send the heated refrigerant and oxidant to Enter the supercritical reactor 40, control the pressure in the supercritical reactor 40 to not be lower than the critical pressure of the refrigerant, and control the temperature in the supercritical reactor 40 to not be lower than the critical temperature of the refrigerant, so that the refrigerant can be in the supercritical state. Thermal degradation is carried out under the condition to generate tail gas, and in the supercritical reactor 40, the refrigerant is in a supercritical state, which not only has high reactivity and good mass transfer performance, can be effectively degraded under low temperature conditions, but also has high density, With high solubility and strong convection-diffusion ability, the volume of refrigerant of the same mass is smaller, which can improve the processing capacity of refrigerant, achieve high concentration, large flow, and rapid decomposition of refrigerant, thereby realizing the refrigerant at low temperature and low energy. Effective degradation under the conditions of high consumption, large flow rate, high refrigerant component ratio. In addition, the preheater 30 is used to heat the pressurized refrigerant and oxidant respectively, and the heated refrigerant and oxidant are sent to the supercritical reactor 40 for degradation, which can avoid long-term heating of the refrigerant and oxidant after being mixed. This leads to the production of toner and clogging problems.

In embodiments of the present invention, the temperature in the supercritical reactor 40 may not be higher than 600°C, and the pressure in the supercritical reactor 40 may not be higher than 20 MPa. This reduces energy consumption and equipment costs.

According to some specific embodiments of the present invention, for refrigerants with low hydrogen content, step (2) also includes using a preheater 30 to heat the pressurized hydrogen-containing compound; in step (3), While the heated refrigerant and oxidant are fed into the supercritical reactor 40 , the heated hydrogen-containing compound is fed into the supercritical reactor 40 . This can provide hydrogen element for the degradation system of the refrigerant that is deficient in hydrogen, so that the refrigerant can be thermally decomposed in a supercritical state with an oxidant and a hydrogen-containing compound. It should be noted that the ratio of the refrigerant, the oxidant and the hydrogen-containing compound is not particularly limited, and those skilled in the art can choose according to actual needs. As a specific example, the refrigerant can be C ₂ H ₂ F ₄ , the oxidant can be O ₂ , the hydrogen-containing compound can be H ₂ O, and the molar ratio of C ₂ H ₂ F ₄ , O ₂ and H ₂ O can be 1 :1.5:1. Furthermore, the oxidant and the hydrogen-containing compound may be slightly excessive, thereby allowing the refrigerant to be fully degraded.

According to some further specific embodiments of the present invention, before step (1), a tightness test is performed on the system of supercritical thermal degradation refrigerant. This ensures the tightness of the system. After ensuring the tightness of the system, use a vacuum pump to evacuate the system to complete the preparations for the degradation reaction. To further increase the reaction rate, a catalyst can be loaded into the supercritical reactor 40 before step (1). The types of catalysts have been described in detail before and will not be described again here.

Furthermore, the method of degrading refrigerant using the supercritical thermally degraded refrigerant system of the above embodiment may also include: (4) cooling and/or purifying the tail gas generated by the degradation of the refrigerant in the supercritical state. In this way, the exhaust gas generated by the degradation of the refrigerant in the supercritical state is cooled and/or the ash is filtered. It should be noted that the cooled and/or purified exhaust gas can be further recycled or treated harmlessly.

The present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are only illustrative and do not limit the present invention in any way.

Example 1

Fill the system with high-pressure nitrogen to check the tightness of the system. After ensuring the tightness of the system, use a vacuum pump to evacuate the system to complete the preparations for the degradation reaction.

Turn on the refrigerant booster device to pressurize C ₂ H ₂ F ₄ , turn on the oxidant booster device to pressurize O ₂ , start the hydrogen-containing compound booster device to pressurize H ₂ O, and adjust C ₂ H through the flow meter respectively. The feed rate of ₂ F ₄ , O ₂ and H ₂ O is such that the molar ratio of C ₂ H ₂ F ₄ , O ₂ and H ₂ O is 1:1.5:1; turn on the preheater to make C ₂ H ₂ F _4. O ₂ and H ₂ O reach 300°C before entering the supercritical reactor; send the heated C ₂ H ₂ F ₄ , O ₂ and H ₂ O into the supercritical reactor, and adjust the furnace temperature of the supercritical reactor Control it at 300°C and the pressure in the supercritical reactor at 15MPa to degrade C ₂ H ₂ F ₄ in the supercritical state (partial pressure 4.29MPa).

Comparative example 1

The temperature reached by the mixture of C ₂ H ₂ F ₄ , O ₂ , and H ₂ O before entering the supercritical reactor is 300°C. The furnace temperature of the supercritical reactor is controlled at 300°C, and the pressure in the supercritical reactor is controlled. At low pressure (0.35MPa), the partial pressure of C ₂ H ₂ F ₄ is 0.1MPa, and the rest is the same as in Example 1.

Comparative example 2

The temperature reached by C ₂ H ₂ F ₄ , O ₂ , and H ₂ O before entering the supercritical reactor is 300°C. The furnace temperature of the supercritical reactor is controlled at 300°C, and the pressure in the supercritical reactor is controlled at pressure (3.5MPa), C ₂ H ₂ F ₄ partial pressure 1MPa, and the rest is the same as in Example 1.

The GC-TCD method was used to analyze the C _{2 H 2 F 4 content of the tail gas produced by the degradation of C 2 H 2 F 4 in the} supercritical state in Example 1 and Comparative Examples 1-2, and the C ₂ H ₂ F ₄ content was calculated. The reduction rate, the results are shown in Table 1.

Table 1

Reactor temperature (℃) Reactor pressure (MPa) Reduction rate of C ₂ H ₂ F ₄ content (%) Example 1 300 15 99.8 Comparative example 1 300 0.35 26.3 Comparative example 2 300 3.5 14.9

It can be seen from Example 1 that the refrigerant degradation method according to the above embodiment of the present invention can effectively degrade the refrigerant under supercritical conditions.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "an example," "specific examples," or "some examples" or the like means that specific features are described in connection with the embodiment or example. , structures, materials or features are included in at least one embodiment or example of the invention. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification unless they are inconsistent with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above-mentioned embodiments are illustrative and should not be construed as limitations of the present invention. Those of ordinary skill in the art can make modifications to the above-mentioned embodiments within the scope of the present invention. The embodiments are subject to changes, modifications, substitutions and variations.

Claims (25)

1. A system for supercritical thermal degradation of refrigerant, characterized in that it includes: A refrigerant boosting device, the refrigerant boosting device has a refrigerant inlet and a high-pressure refrigerant outlet, the refrigerant boosting device includes a first liquid pump and a first flow meter, the first liquid pump and the The first flow meter is connected to the first liquid pump. The first liquid pump is provided with the refrigerant inlet. The first flow meter is provided with the high-pressure refrigerant outlet. The refrigerant boosting device also includes a refrigerant storage container. , a refrigerant pre-pressurizing unit is provided in the refrigerant storage container, the refrigerant storage container is connected to the refrigerant inlet, and the refrigerant pressurizing device is used to pressurize the refrigerant, so that refrigeration The pressure of the refrigerant reaches above the critical pressure of the refrigerant; An oxidant pressurizing device, the oxidant pressurizing device has an oxidant inlet and a high-pressure oxidant outlet; Preheater, the preheater includes a refrigerant heat exchange channel and an oxidant heat exchange channel, the refrigerant heat exchange channel has a high-pressure refrigerant inlet and a high-temperature refrigerant outlet, and the high-pressure refrigerant inlet is connected with the high-pressure refrigeration The oxidant heat exchange channel has a high-pressure oxidant inlet and a high-temperature oxidant outlet, and the high-pressure oxidant inlet is connected to the high-pressure oxidant outlet; A supercritical reactor. The supercritical reactor has a raw material inlet and a first tail gas outlet. The raw material inlet is connected to the high-temperature refrigerant outlet and the high-temperature oxidant outlet respectively. 2. The system of claim 1, wherein the supercritical reactor includes a heater and/or a temperature controller, and/or the preheater includes a heater and/or a temperature controller. 3. The system according to claim 1, characterized in that pressure gauges are provided independently at the raw material inlet and the first exhaust gas outlet. 4. The system of claim 1, wherein the first exhaust gas outlet is connected to a back pressure valve. 5. The system according to claim 1, wherein a one-way valve is provided between the high-pressure oxidant outlet and the high-pressure oxidant inlet. 6. The system according to claim 1, characterized in that a safety valve is provided between the high-pressure oxidant outlet and the high-pressure oxidant inlet and/or at the raw material inlet. 7. The system according to claim 2, wherein the oxidant boosting device includes an oxidant boosting pump and a second flow meter, the oxidant boosting pump is connected to the second flow meter, and the oxidant boosting pump is connected to the second flow meter. The booster pump is provided with the oxidant inlet, and the second flow meter is provided with the high-pressure oxidant outlet. 8. The system according to claim 7, wherein the oxidant boosting device further includes a buffer tank and a pressure reducing valve, the oxidant boosting pump is connected to the buffer tank, and the buffer tank passes through the The pressure reducing valve is connected to the second flow meter. 9. The system according to claim 1 or 2, further comprising: A hydrogen-containing compound pressurizing device, the hydrogen-containing compound pressurizing device has a hydrogen-containing compound inlet and a high-pressure hydrogen-containing compound outlet; The preheater also includes a hydrogen-containing compound heat exchange channel. The hydrogen-containing compound heat exchange channel has a high-pressure hydrogen-containing compound inlet and a high-temperature hydrogen-containing compound outlet. The high-pressure hydrogen-containing compound inlet and the high-pressure hydrogen-containing compound outlet are Connected, the raw material inlet is connected with the high temperature hydrogen-containing compound outlet. 10. The system according to claim 9, wherein the raw material inlet is connected to the high-temperature refrigerant outlet, the high-temperature oxidant outlet, and the high-temperature hydrogen-containing compound outlet respectively through insulated tubes. 11. The system according to claim 9, wherein the hydrogen-containing compound pressurizing device includes a second liquid pump and a third flow meter, the second liquid pump and the third flow meter are connected, so The second liquid pump is provided with the hydrogen-containing compound inlet, and the third flow meter is provided with the high-pressure hydrogen-containing compound outlet. 12. The system of claim 4, further comprising: Exhaust gas treatment device, the exhaust gas treatment device has an exhaust gas inlet and a second exhaust gas outlet, the exhaust gas inlet is connected to the first exhaust gas outlet, and the second exhaust gas outlet is connected to the back pressure valve. 13. The system according to claim 12, wherein the exhaust gas treatment device includes a condenser and a filter, the condenser has the exhaust gas inlet and a low-temperature gas outlet, and the low-temperature gas outlet is connected with the filter. The filter is connected with the second exhaust gas outlet. 14. The system according to claim 13, characterized in that the exhaust gas treatment device further includes a constant temperature oil bath, the condenser further has a cooling medium inlet and a cooling medium outlet, the cooling medium inlet and the cooling medium The outlets are respectively connected with the constant temperature oil bath. 15. The system according to claim 1 or 2, characterized in that a catalyst is provided in the supercritical reactor. 16. The system of claim 15, wherein the catalyst includes at least one of a metal, a metal oxide, and a metal phosphate. 17. A method for degrading refrigerant using a system of supercritical thermally degradable refrigerant according to any one of claims 1 to 16, characterized in that it includes: (1) Use a refrigerant booster device to pressurize the refrigerant, and an oxidant booster device to pressurize the oxidant; (2) Use a preheater to heat the pressurized refrigerant and the oxidant respectively; (3) Send the heated refrigerant and oxidant into a supercritical reactor, control the pressure in the supercritical reactor to not be lower than the critical pressure of the refrigerant, and control the supercritical reactor The temperature inside is not lower than the critical temperature of the refrigerant, so that the refrigerant degrades in the supercritical state. 18. The method of claim 17, wherein step (2) further includes using a preheater to heat the pressurized hydrogen-containing compound; step (3) further includes heating the heated hydrogen-containing compound. The compounds are fed into the supercritical reactor. 19. The method according to claim 17, characterized in that, before step (1), a tightness test is performed on the system of the supercritical thermally degraded refrigerant. 20. The method according to claim 17, characterized in that, before step (1), a catalyst is loaded in the supercritical reactor. 21. The method of claim 17, wherein the refrigerant includes at least one of perchlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons and hydrofluoroolefins. 22. The method of claim 17, wherein the oxidizing agent includes _O2 and/or _{H2O2 .} 23. The method of claim 18, wherein the hydrogen-containing compound includes at least one of H ₂ O, CH ₃ OH, and CH ₃ CH ₂ OH. 24. The method of claim 17 or 18, further comprising: (4) Cool and/or purify the exhaust gas generated by the degradation of the refrigerant in the supercritical state. 25. The method according to claim 17 or 18, characterized in that the temperature in the supercritical reactor is not higher than 600°C, and the pressure in the supercritical reactor is not higher than 20MPa.