Evaluation system, evaluation method, and program

Abstract

The present invention provides an evaluation system, an evaluation method, and a program which enable quantitative evaluation of the reactivity of a working medium. An evaluation system (1) comprises: a reaction vessel (2) inside which a first electrode (31) and a second electrode (32) are disposed and which contains a working medium (200); a capacitor (41) which has two ends that are respectively connected to the first electrode (31) and the second electrode (32), and to which a prescribed DC voltage greater than 2 kV is applied; and a semiconductor switch (42) which is connected between the capacitor (41) and the first electrode (31), and which is for applying pulse energy to the first electrode (31) and the second electrode (32) on the basis of the voltage between the two ends of the capacitor (41).

Description

Evaluation systems, evaluation methods, and programs

[0001] The present disclosure relates to an evaluation system, an evaluation method, and a program.

[0002] Conventionally, R410A has been widely used as a working fluid (heat medium, refrigerant) for refrigeration cycle devices. However, R410A has a high global warming potential (GWP) of 2090. Therefore, from the perspective of preventing global warming, research and development has been conducted on working fluids with lower GWP. Patent Document 1 discloses 1,1,2-trifluoroethylene (HFO1123) as a working fluid with a lower GWP than R410A. Patent Document 2 discloses 1,2-difluoroethylene (HFO1132) as a working fluid with a lower GWP than R410A.

[0003] HFO1123 and HFO1132 have a smaller GWP than R410A, but this makes them less stable than R410A. For example, the generation of radicals can cause disproportionation reactions of HFO1123 or HFO1132, which can change HFO1123 and HFO1132 into other compounds.

[0004] Patent Document 3 discloses a discharge device for determining the extent of a disproportionation reaction in a refrigerant. The discharge device disclosed in Patent Document 3 includes a first electrode and a second electrode, a capacitor, and a reactor unit. The first electrode and the second electrode are spaced apart from each other. The capacitor stores energy to apply a first voltage between the first electrode and the second electrode. The reactor unit includes a first reactor and a second reactor. The reactor unit generates a second voltage applied between the first electrode and the second electrode by induction, thereby initiating a discharge of energy between the first electrode and the second electrode.

[0005] International Publication No. 2012 / 157764 International Publication No. 2012 / 157765 JP 2023-56188 A

[0006] In the discharge device disclosed in Patent Document 3, in order to generate the second voltage by induction to start the discharge of energy between the first electrode and the second electrode, it is necessary to apply the first voltage between the first electrode and the second electrode in advance. Furthermore, since the second voltage is generated by induction, the degree of freedom in setting the period during which the second voltage is applied is low. Therefore, it is difficult to quantitatively evaluate the reactivity (stability) of the working medium.

[0007] The present disclosure provides an evaluation system, an evaluation method, and a program that enable quantitative evaluation of the reactivity of a working medium.

[0008] An evaluation system according to one aspect of the present disclosure includes: a reaction vessel having a first electrode and a second electrode disposed therein and containing a working medium; a capacitor having both ends connected to the first electrode and the second electrode, respectively, and having a predetermined DC voltage greater than 2 kV applied thereto; and a semiconductor switch connected between the capacitor and the first electrode, for applying pulse energy to the first electrode and the second electrode based on the voltage across the capacitor.

[0009] An evaluation method according to one aspect of the present disclosure is a method for evaluating a reaction of a working medium that is executed in an evaluation system, the evaluation system comprising: a reaction vessel having a first electrode and a second electrode disposed therein and containing a working medium; a capacitor having both ends connected to each of the first electrode and the second electrode and to which a predetermined DC voltage is applied; a semiconductor switch connected between the capacitor and the first electrode and for applying pulse energy to the first electrode and the second electrode based on the voltage across the capacitor; and a computing device, wherein the evaluation method is executed by the computing device and includes determining a value of discharge energy as the reaction of the working medium progresses based on changes over time in voltage and current between the first electrode and the second electrode associated with discharge generated by applying pulse energy to the first electrode and the second electrode, or the capacitance and charging voltage of the capacitor.

[0010] A program according to one aspect of the present disclosure is a program for causing a computing device to execute the evaluation method.

[0011] Aspects of the present disclosure allow for quantitative assessment of working medium reactivity.

[0012] a block diagram of a refrigeration cycle device including a refrigeration cycle circuit through which a working medium circulates; a block diagram of a compressor and a control device of the refrigeration cycle circuit; a circuit block diagram of an evaluation system for executing an evaluation method according to an embodiment; an explanatory diagram of the arrangement of a first electrode and a second electrode of a discharge generator of the evaluation system according to an embodiment; a flowchart of an example of a working medium evaluation method according to an embodiment; a flowchart of a reaction progress determination method in an evaluation method for a working medium according to an embodiment; a flowchart of a discharge power analysis method in an evaluation method for a working medium according to an embodiment; a graph showing a time change in voltage due to discharge; a graph showing a time change in current due to discharge; a graph showing a relationship between voltage and current due to discharge; a graph showing a time change in power due to discharge; a flowchart of an example of a method for evaluating a refrigeration cycle circuit according to an embodiment; a flowchart of an example of a method for determining the composition of a working medium according to an embodiment; a flowchart of an example of a method for determining the configuration of a refrigeration cycle circuit according to an embodiment;

[0013] [1. Embodiments] Hereinafter, embodiments of the present disclosure will be described, with reference to the drawings where appropriate. However, the following embodiments are merely examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following content (e.g., the shape, dimensions, and arrangement of each component). Positional relationships, such as up, down, left, and right, are based on the positional relationships shown in the drawings unless otherwise specified. Each figure described in the following embodiments is a schematic diagram, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios. Furthermore, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

[0014] In the following description, when it is necessary to distinguish between multiple components, prefixes such as "first" and "second" are added to the names of the components. However, when the components can be distinguished from each other by the symbols attached to them, the prefixes such as "first" and "second" may be omitted in consideration of readability of the text.

[0015] [1.1 Configuration] The evaluation method according to the present embodiment can be used to evaluate a refrigeration cycle device, in particular, to evaluate a working medium (heat medium, refrigerant) for the refrigeration cycle device, and to evaluate the risk of damage to a refrigeration cycle circuit through which the working medium circulates.

[0016] First, an example of a refrigeration cycle apparatus will be described with reference to Fig. 1. Fig. 1 is a block diagram of a refrigeration cycle apparatus 100. The refrigeration cycle apparatus 100 constitutes, for example, an air conditioner capable of cooling operation and heating operation. The refrigeration cycle apparatus 100 includes a refrigeration cycle circuit 102 and a control device 103.

[0017] The refrigeration cycle circuit 102 constitutes a flow path through which a working medium 200 (see FIG. 2) circulates.

[0018] The refrigeration cycle circuit 102 includes a compressor 104, a first heat exchanger 105, an expansion valve 106, a second heat exchanger 107, and a four-way valve 108. The compressor 104, the first heat exchanger 105, the expansion valve 106, the second heat exchanger 107, and the four-way valve 108 are connected by piping 109 to form a flow path through which the working medium 200 circulates.

[0019] The refrigeration cycle apparatus 100 includes an outdoor unit 101a and an indoor unit 101b. The outdoor unit 101a includes a control device 103, a compressor 104, a first heat exchanger 105, an expansion valve 106, and a four-way valve 108. The outdoor unit 101a further includes a first fan 105a for promoting heat exchange in the first heat exchanger 105. The indoor unit 101b includes a second heat exchanger 107. The indoor unit 101b further includes a second fan 107a for promoting heat exchange in the second heat exchanger 107.

[0020] The compressor 104 compresses the working medium 200 to increase the pressure of the working medium 200. The compressor 104 will be described later.

[0021] The first heat exchanger 105 and the second heat exchanger 107 exchange heat between the working medium 200 circulating through the refrigeration cycle circuit 102 and external air (for example, outside air or room air).

[0022] The expansion valve 106 adjusts the pressure (evaporation pressure) of the working medium 200 and the flow rate of the working medium 200 .

[0023] The four-way valve 108 switches the direction of the working medium 200 circulating through the refrigeration cycle circuit 102 between a first direction corresponding to cooling operation and a second direction corresponding to heating operation.

[0024] The first direction is the direction in which the working medium 200 circulates through the refrigeration cycle circuit 102 in the order of the compressor 104, the first heat exchanger 105, the expansion valve 106, and the second heat exchanger 107, as shown by the solid arrow A1 in Figure 1.

[0025] In cooling operation, the compressor 104 compresses and discharges the gaseous working medium 200, which is then sent to the first heat exchanger 105 via the four-way valve 108. The first heat exchanger 105 exchanges heat between the outside air and the gaseous working medium 200, causing the gaseous working medium 200 to condense and liquefy. The liquid working medium 200 is depressurized by the expansion valve 106 and sent to the second heat exchanger 107. In the second heat exchanger 107, the liquid working medium 200 exchanges heat with the room air, causing the liquid working medium 200 to evaporate and become the gaseous working medium 200. The gaseous working medium 200 returns to the compressor 104 via the four-way valve 108. In cooling operation, the first heat exchanger 105 functions as a condenser, and the second heat exchanger 107 functions as an evaporator. Therefore, during cooling, the indoor unit 101b blows air cooled by heat exchange in the second heat exchanger 107 into the room.

[0026] The second direction is the direction in which the working medium 200 circulates through the refrigeration cycle circuit 102 in the order of the compressor 104, the second heat exchanger 107, the expansion valve 106, and the first heat exchanger 105, as shown by the dashed arrow A2 in Figure 1.

[0027] In heating operation, the compressor 104 compresses and discharges the gaseous working medium 200, which is then sent to the second heat exchanger 107 via the four-way valve 108. The second heat exchanger 107 exchanges heat between the room air and the gaseous working medium 200, causing the gaseous working medium 200 to condense and become a liquid. The liquid working medium 200 is decompressed by the expansion valve 106 and sent to the first heat exchanger 105. In the first heat exchanger 105, heat is exchanged between the liquid working medium 200 and outside air, causing the gaseous working medium 200 to evaporate and become the gaseous working medium 200. The gaseous working medium 200 returns to the compressor 104 via the four-way valve 108. In heating operation, the first heat exchanger 105 functions as an evaporator, and the second heat exchanger 107 functions as a condenser. Therefore, during heating, the indoor unit 101b blows air that has been heated by heat exchange in the second heat exchanger 107 into the room.

[0028] The control device 103 controls the compressor 104 of the refrigeration cycle circuit 102 .

[0029] The compressor 104 and the control device 103 will be described with reference to Fig. 2. Fig. 2 is a block diagram of the compressor 104 and the control device 103.

[0030] The compressor 104 is, for example, a hermetic compressor. The compressor 104 may be a rotary type, a scroll type, or any other known type. The compressor 104 includes a hermetic container 1040, a compression mechanism 1041, and an electric motor 1042.

[0031] The sealed container 1040 forms a flow path for the working medium 200. The sealed container 1040 has a suction pipe 1040a and a discharge pipe 1040b. The working medium 200 is sucked into the sealed container 1040 from the suction pipe 1040a, compressed by the compression mechanism 1041, and then discharged to the outside of the sealed container 1040 from the discharge pipe 1040b. The inside of the sealed container 1040 is filled with the high-temperature and high-pressure working medium 200 and lubricating oil. The bottom of the sealed container 1040 forms an oil reservoir that stores a mixture of the working medium 200 and lubricating oil.

[0032] The compression mechanism 1041 is located in the sealed container 1040 and compresses the working medium 200. The compression mechanism 1041 may have a conventionally known configuration. The compression mechanism 1041 has, for example, a cylinder that forms a compression chamber, a rolling piston that is disposed in the compression chamber inside the cylinder, and a crankshaft that is coupled to the rolling piston.

[0033] The electric motor 1042 is located within the sealed container 1040 and drives the compression mechanism 1041. The electric motor 1042 is, for example, a brushless motor (three-phase brushless motor). The electric motor 1042 includes, for example, a rotor 1042a fixed to the crankshaft of the compression mechanism 1041 and a stator 1042b disposed around the rotor 1042a. The stator 1042b includes, for example, a stator core (such as an electromagnetic steel plate) and multiple coils formed by concentrating or dispersing stator windings (such as magnet wire) around the stator core via an insulating material such as insulating paper. The stator windings are covered with an insulating material. Examples of insulating materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), aramid polymer, polyphenylene sulfide (PPS), and polytetrafluoroethylene (PTFE).

[0034] The control device 103 includes a drive circuit 1031 and a control circuit 1032 .

[0035] The drive circuit 1031 is a power source for the compressor 104. More specifically, the drive circuit 1031 drives the electric motor 1042 of the compressor 104 based on input power from a power source. For example, the power source is an AC power source, and the input power is AC power. The drive circuit 1031 may have a conventionally known configuration and may be either an inverter type or a constant speed type. The inverter type includes an inverter capable of changing the frequency and voltage and has the function of changing the rotation speed of the compressor 104. The inverter type can be considered a variable speed type. The constant speed type does not include an inverter capable of changing the frequency and voltage and does not have the function of changing the rotation speed of the compressor 104.

[0036] The control circuit 1032 can be realized by, for example, a computer system including at least one processor (microprocessor) and one or more memories. The control circuit 1032 controls the drive circuit 1031 so that the drive circuit 1031 operates the electric motor 1042. When the drive circuit 1031 includes an inverter, the control circuit 1032 can control the frequency and amplitude of the AC voltage applied from the drive circuit 1031 to the compressor 104.

[0037] In designing the refrigeration cycle apparatus 100 described above, it is preferable to appropriately set the reactivity of the working medium 200 and the pressure resistance of the refrigeration cycle circuit 102 .

[0038] Next, an example of the evaluation method according to this embodiment, particularly, the method for evaluating the reactivity of a working fluid for a refrigeration cycle device will be described.

[0039] The disproportionation reaction of the working fluid is thought to be caused by heat and radicals. For example, it is thought that the disproportionation reaction of the working fluid progresses when radicals are generated under high temperature and high pressure. Radicals may be generated by a discharge phenomenon that may occur when some abnormality occurs in the compressor 104 or the drive circuit 1031, for example. Therefore, in this embodiment, the reactivity of the working fluid is evaluated by utilizing discharge.

[0040] In this embodiment, an evaluation system 1 shown in FIG. 3 is used to evaluate the reactivity of the working fluid.

[0041] 3 is a circuit block diagram of the evaluation system 1. The evaluation system 1 includes a reaction vessel 2, a discharge circuit 3, a drive circuit 4, a reaction measurement device 5, a discharge measurement device 6, a DC power supply 7, and a calculation device 8. In the evaluation system 1, the discharge circuit 3 and the drive circuit 4 constitute a discharge generator 10.

[0042] The reaction vessel 2 includes a vessel body 21 , a control valve 22 , and a temperature controller 23 .

[0043] The vessel body 21 accommodates the working medium. In particular, the vessel body 21 is sealed to prevent leakage of the working medium from the vessel body 21. The design pressure resistance of the vessel body 21 (reaction vessel 2) may be set based on the pressure expected in the evaluation test of the working medium. It is preferable that the design pressure resistance is sufficiently higher than the pressure expected in the evaluation test of the working medium. This reduces the possibility of the reaction vessel 2 being damaged by a sudden increase in pressure even if the initial pressure is increased. As an example, if the pressure expected in the evaluation test of the working medium is 6 MPa, the design pressure resistance should be 30 MPa or more. This improves safety during evaluation.

[0044] The control valve 22 is provided in the vessel body 21. The control valve 22 is set to open when the pressure inside the reaction vessel 2 reaches or exceeds two-thirds of the design pressure. Such a control valve 22 is also called a pressure relief valve. This improves safety during evaluation. Here, by setting the pressure at which the control valve 22 opens to two-thirds of the design pressure, leakage from the reaction vessel 2 can be prevented even in the event of a momentary pressure rise, improving the safety of the evaluation test.

[0045] The temperature controller 23 controls the temperature inside the reaction vessel 2. The temperature controller 23 is, for example, an electric heater. The temperature range that can be controlled by the temperature controller 23 may be set based on the temperature required in the evaluation test of the working fluid. As an example, when the working fluid is a working medium, the temperature controller 23 may be capable of controlling the temperature in the range from room temperature to 200°C. This configuration can improve the degree of freedom in setting the conditions for the evaluation test.

[0046] The discharge circuit 3 has a first electrode 31 and a second electrode 32. In this embodiment, the first electrode 31 is a high-potential electrode, and the second electrode 32 is a low-potential electrode. The first electrode 31 and the second electrode 32 are disposed inside the reaction vessel 2 (vessel body 21). The first electrode 31 and the second electrode 32 are rod-shaped. As an example, the first electrode 31 and the second electrode 32 are round rod-shaped.

[0047] The distance D between the first electrode 31 and the second electrode 32 is 30 μm or more, which makes it easier for discharge to occur.

[0048] FIG. 4 is an explanatory diagram of the arrangement of the first electrode 31 and the second electrode 32. In this embodiment, the central axes C31, C32 of the first electrode 31 and the second electrode 32 do not coincide with each other. This improves the stability of discharge generation. In particular, the central axes C31, C32 of the first electrode 31 and the second electrode 32 are parallel to each other. In other words, the central axes C31, C32 of the first electrode 31 and the second electrode 32 are parallel to a predetermined first direction X. The first electrode 31 and the second electrode 32 face each other in a direction perpendicular to the central axes C31, C32 of the first electrode 31 and the second electrode 32. In other words, the first electrode 31 and the second electrode 32 each have portions 31a, 32a that face each other in a second direction Y perpendicular to the first direction X. The length g of the portions 31a, 32a of the first electrode 31 and the second electrode 32 is preferably 0.5 mm or more. Even if the discharge causes sputtering and increases the distance D, making it difficult to generate a discharge, the length g at which discharge is possible can be secured, making it possible to generate hundreds of continuous discharges. This improves the stability of discharge generation.

[0049] It is preferable that the conductivity of the first electrode 31 and the second electrode 32 is high. If the conductivity of the first electrode 31 and the second electrode 32 is high, the voltage drop between both ends of the first electrode 31 and the second electrode 32 is small, and therefore the difference between the voltage between the first electrode 31 and the second electrode 32 obtained by measurement and the actual voltage between the first electrode 31 and the second electrode 32 is small. This allows for more accurate evaluation. In this embodiment, the conductivity of the material of the first electrode 31 and the second electrode 32 is 1×10 ７ This makes it possible to reduce the influence of voltage drop at the first electrode 31 and the second electrode 32.

[0050] The drive circuit 4 is provided to generate a discharge between the first electrode 31 and the second electrode 32. The drive circuit 4 includes a capacitor 41, a semiconductor switch 42, a current limiter 43, and a pulse power supply 44.

[0051] The capacitor 41 stores energy for generating a discharge between the first electrode 31 and the second electrode 32. In this embodiment, a predetermined DC voltage is applied to the capacitor 41. Both ends of the capacitor 41 (a high-potential terminal 41a and a low-potential terminal 41b) are connected to the first electrode 31 and the second electrode 32, respectively. The low-potential terminal 41b and the second electrode 32 of the capacitor 41 do not need to be directly connected by a conductor or the like, but may be equivalently connected by being connected to ground. The capacitance of the capacitor 41 is 20 pF to 10 mF, preferably 20 pF to 0.5 mF. This allows for greater flexibility in setting the discharge energy required to generate a reaction. The capacitor 41 may be composed of a single capacitance element or multiple capacitance elements. When the capacitor 41 is composed of multiple capacitance elements, the capacitance of the capacitor 41 can be expressed as the combined capacitance of the multiple capacitance elements. Examples of capacitance elements include a film capacitor and a multilayer ceramic capacitor.

[0052] The semiconductor switch 42 is connected between (the high potential terminal 41 a of) the capacitor 41 and the first electrode 31. The semiconductor switch 42 is used to apply pulse energy to the discharge circuit 3 based on the voltage across the capacitor 41. It is preferable that the semiconductor switch 42 be able to withstand a large current. For example, it is preferable that the allowable peak current value of the semiconductor switch 42 is 500 A or more.

[0053] The current limiter 43 limits at least one of the pulse width and maximum power value (maximum current value) of the applied pulse (pulse current). Pulse energy is applied to the first electrode 31 and the second electrode 32 by the applied pulse. The magnitude of the pulse energy is given by the product of the pulse power and the pulse width of the applied pulse. The current limiter 43 is connected between the capacitor 41 (the high-potential terminal 41 a) or the first electrode 31 and the semiconductor switch 42. In this embodiment, the current limiter 43 is connected between the first electrode 31 and the semiconductor switch 42. The current limiter 43 may include at least one of a resistor and a reactor. The resistor is mainly used to set the maximum power value of the applied pulse. The resistance value of the resistor is preferably 20 Ω or less. The reactor is mainly used to set the pulse width of the applied pulse. The inductive reactance of the reactor is preferably 20 H or less. The presence of the current limiter 43 improves the flexibility in setting the discharge energy or time for causing a reaction.

[0054] The pulse power supply 44 is used to set the on / off state of the semiconductor switch 42. In particular, the pulse power supply 44 supplies a pulse signal to the semiconductor switch 42 to turn it on. The pulse width of the pulse signal affects the pulse width of the applied pulse supplied from the drive circuit 4 to the discharge circuit 3. As an example, the voltage of the pulse signal can be 5 V and the pulse width can be 10 μs. An example of the pulse power supply 44 is a TTL (Transistor-Transistor-Logic) power supply, but is not particularly limited thereto, and any conventionally known pulse power supply can be used. Using the pulse power supply 44 makes it easy to output an applied pulse from the drive circuit 4 to the discharge circuit 3. This contributes to improving the degree of freedom in setting the discharge conditions for causing a reaction.

[0055] In the drive circuit 4, the impedance of the electrical path 45 between the capacitor 41 and the discharge circuit 3 is preferably low. The electrical path 45 includes a high-potential-side electrical path 451 between the high-potential-side terminal 41a of the capacitor 41 and the first electrode 31, and a low-potential-side electrical path 452 between the low-potential-side terminal 41b of the capacitor 41 and the second electrode 32. In FIG. 3 , the high-potential-side electrical path 451 includes a first portion 451a between the high-potential-side terminal 41a of the capacitor 41 and the semiconductor switch 42, a second portion 451b between the semiconductor switch 42 and the current limiter 43, and a third portion 451c between the current limiter 43 and the first electrode 31. This reduces the voltage drop in the electrical path 45 and energy loss. The impedance of the electrical path 45 is the combined impedance of the impedance of the high-potential-side electrical path 451 and the impedance of the low-potential-side electrical path 452. For example, the impedance of the electric circuit 45 is preferably 1.5Ω or less, more preferably 1.0Ω or less, and even more preferably 0.5Ω or less. This can suppress the attenuation of energy, thereby improving the degree of freedom in setting the discharge conditions for causing the reaction. Here, the material of the conductor used for the electric circuit 45 is preferably a highly conductive material, and for example, a material with a conductivity of 1×10 ７ In the electric circuit 45, the portion inside the reaction vessel 2 preferably has a wire diameter of AWG 30 or more and a length of 1 m or less. The portion outside the reaction vessel 2 preferably has a wire diameter of AWG 12 or more and a length of 10 m or less.

[0056] In the drive circuit 4, to output an applied pulse with a pulse width of 10 μs, the inductance of the electric circuit 45 between the capacitor 41 including the semiconductor switch 42 and the discharge circuit 3 is preferably low. For example, the inductance of the electric circuit 45 is preferably 10 μH or less. Furthermore, if the capacitance of the capacitor 41 is set to 100 nF so as to be able to store 5 J of energy, to output an applied pulse with a pulse width of 1 μs, the inductance of the electric circuit 45 is preferably 0.25 μH or less. In addition, to shorten the pulse width, the impedance of the electric circuit 45 is preferably low. For example, if the capacitance of the capacitor 41 is set to 100 nF so as to be able to store 5 J of energy, to output an applied pulse with a pulse width of 1 μs, the impedance of the electric circuit 45 is preferably 1.5 Ω or less.

[0057] In this way, the drive circuit 4 outputs an applied pulse to the discharge circuit 3. The drive circuit 4 makes it possible to vary the instantaneous energy of the applied pulse in the range of several hundred MW to several kW. The drive circuit 4 also makes it possible to vary the pulse width of the applied pulse in the range of 1 μs to 1 ms. This improves the degree of freedom in setting the discharge conditions for causing a reaction.

[0058] The reaction measurement device 5 is provided to measure the reaction in the reaction vessel 2. In other words, the reaction measurement device 5 is provided to quantitatively evaluate the degree of progress of the reaction in the reaction vessel 2. The reaction measurement device 5 includes at least one of a pressure sensor that measures the pressure in the reaction vessel 2 and a temperature sensor that measures the temperature in the reaction vessel 2. The reaction measurement device 5 outputs reaction information that indicates at least one of the pressure and temperature in the reaction vessel 2. In this embodiment, the reaction measurement device 5 includes both a pressure sensor and a temperature sensor, and acquires information about both the pressure and temperature in the reaction vessel 2.

[0059] The pressure sensor may include, for example, a high-speed pressure gauge. A high-speed pressure gauge can detect instantaneous changes (on the order of milliseconds) and evaluate the reaction rate for the entire working medium in the reaction vessel. This improves the quantitativeness of reaction detection. In this way, it is possible to measure instantaneous pressure changes and improve the accuracy of reaction measurement.

[0060] The temperature sensor may include, for example, a thermocouple. A thermocouple can detect instantaneous (on the order of milliseconds) changes in temperature due to slight heat of reaction, and can detect even when only a portion of the working fluid in the reaction vessel has reacted, improving the sensitivity of detecting whether the reaction has succeeded or not. In this way, it is possible to measure instantaneous temperature changes and improve the accuracy of reaction measurement.

[0061] The discharge measuring device 6 is provided to measure the discharge of the discharge circuit 3. In other words, the discharge measuring device 6 is provided to quantitatively evaluate the discharge of the discharge circuit 3. The discharge measuring device 6 has a voltage probe 61 and a current probe 62. The discharge measuring device 6 outputs discharge information indicating the voltage and current of the discharge circuit 3. This can improve sensitivity to discharge.

[0062] The voltage probe 61 measures the time change of the voltage between the first electrode 31 and the second electrode 32 of the discharge circuit 3 (the voltage of the discharge circuit 3). In FIG. 3 , both ends of the voltage probe 61 are connected to the first electrode 31 and the second electrode 32, respectively. The voltage probe 61 includes a differential voltmeter with a bandwidth of 20 MHz or higher. This allows measurement of the time change of the voltage in the sub-μs region. This improves the accuracy of measuring the voltage of the discharge circuit 3. The withstand voltage of the differential voltmeter is preferably 3 kV or higher. In particular, the wiring length between the input end of the voltage probe 61 and the first electrode 31 is preferably within 1 m. Furthermore, the voltage probe 61 is preferably positioned near the reaction vessel 2. This reduces the voltage drop caused by the wiring length.

[0063] The current probe 62 measures the change over time of the current flowing between the first electrode 31 and the second electrode 32 of the discharge circuit 3 (the current of the discharge circuit 3). In FIG. 3 , the current probe 62 measures the current flowing in the electrical path between the second electrode 32 and the low-potential terminal of the capacitor 41 as the current of the discharge circuit 3 (the current between the first electrode 31 and the second electrode 32). The current probe 62 includes a non-contact ammeter with a frequency band of 20 MHz or higher. This allows the measurement of the change over time of the current in the sub-μs region. This improves the accuracy of the current measurement. Examples of non-contact ammeters include a Hall element type or a Rogowski coil type ammeter.

[0064] The DC power supply 7 is provided to apply a predetermined DC voltage to the capacitor 41. That is, the DC power supply 7 is arranged to provide the capacitor 41 with energy for the applied pulse. In FIG. 3 , both ends of the DC power supply 7 are connected to both ends of the capacitor 41, respectively. The predetermined DC voltage may be set based on the energy required in the evaluation test of the working medium. As an example, when the working medium is a working fluid, the predetermined DC voltage may be greater than 2 kV. This improves the degree of freedom in setting the discharge conditions for causing the reaction. The DC power supply 7 may have a conventionally known configuration and may be configured using an existing DC power supply, an AC power supply, a rectifier circuit, a boost circuit, etc. as appropriate.

[0065] The arithmetic device 8 may be realized, for example, by a computer system. The computer system includes one or more human-machine interfaces for inputting information, one or more communication interfaces, one or more storage devices, one or more processors (microprocessors), etc. The one or more processors execute programs (stored in one or more storage devices) to realize various functions of the evaluation system 1. The programs may be pre-recorded in the storage device of the computer system, or may be provided via a telecommunications line such as the Internet, or may be recorded on a non-transitory recording medium such as a memory card. The arithmetic device 8 may be realized, for example, by a personal computer (desktop computer, laptop computer), a mobile terminal (smartphone, tablet terminal, etc.), etc.

[0066] The computing device 8 controls the discharge generator 10 (the discharge circuit 3 and the drive circuit 4) based on the specified evaluation test conditions. The evaluation test conditions may include discharge conditions and environmental conditions (pressure or temperature conditions inside the reaction vessel 2). Based on the discharge conditions, the computing device 8 controls the pulse power supply 44 to cause the semiconductor switch 42 to output a pulse signal, thereby outputting an application pulse to the discharge circuit 3. Based on the temperature conditions inside the reaction vessel 2, the computing device 8 controls the temperature controller 23 to set the temperature inside the reaction vessel 2.

[0067] The calculation device 8 acquires information by communicating with the reaction measurement device 5 and the discharge measurement device 6. The calculation device 8 can receive reaction information indicating at least one of the pressure and temperature inside the reaction vessel 2 from the reaction measurement device 5, and can receive discharge information indicating the voltage and current of the discharge circuit 3 from the discharge measurement device 6.

[0068] FIG. 5 is a flowchart of an example of the evaluation method according to this embodiment, in particular, a method of evaluating a working fluid for a refrigeration cycle device.

[0069] To start the evaluation of the working fluid, the evaluation conditions are set (S1). To set the evaluation conditions, first, the working fluid is determined.

[0070] Examples of components used in the working fluid include, but are not limited to, ethylene-based fluoroolefins. Examples of ethylene-based fluoroolefins include 1,1,2-trifluoroethylene (HFO1123), trans-1,2-difluoroethylene (HFO1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), tetrafluoroethylene (CF ２ =CF ２ , FO1114), and monofluoroethylene (HFO-1141).

[0071] The working fluid may contain multiple types of refrigerant components. The working fluid may contain an ethylene-based fluoroolefin as a main refrigerant component and a compound other than an ethylene-based fluoroolefin as a secondary refrigerant component. Examples of the secondary refrigerant component include hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), saturated hydrocarbons, carbon dioxide, etc. Examples of hydrofluorocarbons (HFCs) include difluoromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluorobutane, heptafluorocyclopentane, etc. Examples of hydrofluoroolefins (HFOs) include monofluoropropene, trifluoropropene, tetrafluoropropene, pentafluoropropene, hexafluorobutene, etc. Examples of saturated hydrocarbons include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), methylcyclobutane, and the like.

[0072] The working fluid may further contain a disproportionation inhibitor that suppresses the disproportionation reaction of the ethylenic fluoroolefin. Examples of disproportionation inhibitors include saturated hydrocarbons or haloalkanes. Examples of saturated hydrocarbons include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), methylcyclobutane, and the like. Of the above examples, n-propane is preferred. Examples of haloalkanes include haloalkanes having 1 or 2 carbon atoms. Examples of haloalkanes having 1 carbon atom (i.e., halomethanes) include (mono)iodomethane (CH ３ I), diiodomethane (CH ２ I ２ ), dibromomethane (CH ２ Br ２ ), bromomethane (CH ３ Br), dichloromethane (CH ２ Cl ２), chloroiodomethane (CH ２ ClI), dibromochloromethane (CHBr ２ Cl), tetraiodomethane (Cl ４ ), carbon tetrabromide (CBr ４ ), bromotrichloromethane (CBrCl ３ ), dibromodichloromethane (CBr ２ Cl ２ ), tribromofluoromethane (CBr ３ F), fluorodiiodomethane (CHFI ２ ), difluorodiiodomethane (CF ２ I ２ ), dibromodifluoromethane (CBr ２ F ２ ), trifluoroiodomethane (CF ３ Examples of haloalkanes having two carbon atoms (i.e., haloethanes) include 1,1,1-trifluoro-2-iodoethane (CF ３ CH ２ I), monoiodoethane (CH ３ CH ２ I), monobromoethane (CH ３ CH ２ Br), 1,1,1-triiodoethane (CH ３ CI ３ The working fluid may contain one or more haloalkanes having 1 or 2 carbon atoms. That is, only one type of haloalkane having 1 or 2 carbon atoms may be used, or two or more types may be used in appropriate combination.

[0073] Next, the discharge conditions and environmental conditions (pressure or temperature conditions inside the reaction vessel 2) are determined taking into consideration the expected usage conditions of the working medium.

[0074] Next, the working medium is filled into the reaction vessel 2 (S2).

[0075] The pressure and temperature inside the reaction vessel 2 filled with the working medium are set (S3). Here, the computing device 8 controls the temperature controller 23 based on the temperature conditions inside the reaction vessel 2 to set the temperature inside the reaction vessel 2. If there is a requirement for the pressure inside the reaction vessel 2, the vessel body 21 and the control valve 22 of the reaction vessel 2 can be selected to meet the requirement for the pressure inside the reaction vessel 2.

[0076] The pulse energy is set based on the discharge conditions (S4). The pulse energy setting mainly includes setting the pulse width of the applied pulse and the maximum power value of the pulse power. The pulse width and maximum power value of the applied pulse include settings for the drive circuit 4 and the DC power supply 7.

[0077] The settings of the drive circuit 4 may include settings of a capacitor 41 , a semiconductor switch 42 , a current limiter 43 and a pulsed power supply 44 .

[0078] Setting the capacitor 41 may include setting the capacitance of the capacitor 41 based on the maximum power value of the applied pulse. Setting the capacitance of the capacitor 41 may include changing the capacitance of the capacitor 41 or replacing the capacitor 41.

[0079] The setting of the semiconductor switch 42 may include setting the allowable peak current of the semiconductor switch 42 based on the maximum power value of the applied pulse. The setting of the allowable peak current of the semiconductor switch 42 may include changing the allowable peak current of the semiconductor switch 42 or replacing the semiconductor switch 42.

[0080] Setting the current limiter 43 may include setting the inductive reactance of the reactor based on the pulse width of the applied pulse and / or setting the resistance value of the resistor based on the allowable peak current value of the semiconductor switch 42. Setting the inductive reactance of the reactor may include changing the inductive reactance of the reactor or replacing the reactor. Setting the resistance value of the resistor may include changing the resistance value of the resistor or replacing the resistor.

[0081] The setting of the pulse power supply 44 may include setting the power supply 44 so as to be able to output a pulse signal corresponding to the pulse width of the applied pulse. Setting the pulse width of the pulse signal of the pulse power supply 44 may include changing the pulse width of the pulse signal of the pulse power supply 44 or replacing the pulse power supply 44.

[0082] Setting the DC power supply 7 may include setting the DC voltage of the DC power supply 7 based on the maximum power value of the applied pulse. Setting the DC voltage of the DC power supply 7 may include changing the DC voltage of the DC power supply 7 or replacing the DC power supply 7.

[0083] After the pressure and temperature settings (S3) and pulse energy settings (S4) are completed, discharge is started by the discharge generator 10 (S5). The computing device 8 controls the pulse power supply 44 to output a pulse signal to the semiconductor switch 42, which in turn outputs an application pulse to the discharge circuit 3, applying pulse energy and generating a discharge.

[0084] Acquire reaction information (S6). The calculation device 8 can receive reaction information indicating at least one of the pressure and temperature inside the reaction vessel 2 from the reaction measurement device 5.

[0085] The discharge power is analyzed (S7). The calculation device 8 analyzes the discharge power based on the discharge information and can calculate the discharge energy. The method for calculating the discharge energy will be described later.

[0086] Next, it is determined whether a reaction has progressed in the working medium in the reaction vessel 2 (S8). The calculation device 8 determines whether a reaction is progressing in the working medium in the reaction vessel 2 based on the degree of progress of the reaction. The degree of progress of the reaction is calculated based on a change in at least one of the temperature in the reaction vessel 2 and the pressure in the reaction vessel 2 during a predetermined period from the occurrence of discharge caused by supplying pulse energy from the capacitor 41 to the first electrode 31 and the second electrode 32 disposed in the reaction vessel 2 containing the working medium. The predetermined period is not particularly limited, but may be, for example, 60 seconds.

[0087] The maximum pressure in the reaction vessel during a predetermined period (e.g., 60 seconds) from the occurrence of the discharge is defined as the maximum pressure Pmax [MPa], and the pressure in the reaction vessel before the occurrence of the discharge is defined as the initial pressure Pini [MPa]. The degree of progress of the reaction may be expressed as Pmax / Pini. In this case, if Pmax / Pini > 1.5 is established, it may be determined that the reaction of the working medium has progressed. In other words, if the pressure in the reaction vessel 2 becomes 1.5 times or more the pressure before the occurrence of the discharge within the predetermined period, it may be determined that the reaction of the working medium has progressed.

[0088] The maximum temperature inside the reaction vessel during a predetermined period from the occurrence of discharge is defined as maximum temperature Tmax [K], and the temperature inside the reaction vessel before the occurrence of discharge is defined as initial temperature Tini [K]. The degree of reaction progress may be expressed as Tmax / Tini. In this case, if Tmax / Tini > 1.5 holds, it may be determined that the reaction of the working medium has progressed. In other words, if the temperature inside the reaction vessel 2 becomes 1.5 times or more higher than the temperature before the occurrence of discharge within a predetermined period, it may be determined that the reaction of the working medium has progressed.

[0089] Next, an example of determining the progress of a reaction will be described with reference to Figure 6. Figure 6 is a flowchart of an example of determining the progress of a reaction.

[0090] The calculation device 8 determines whether Pmax satisfies Pmax>Pini+0.5 MPa (S21).

[0091] If Pmax satisfies Pmax > Pini + 0.5 MPa (S21: YES), the calculation device 8 calculates the degree of progress of the reaction. The degree of progress of the reaction is Pmax / Pini and Tmax / Tini. The calculation device 8 determines whether at least one of Pmax / Pini > 1.5 and Tmax / Tini > 1.5 is true (S22).

[0092] If at least one of Pmax / Pini>1.5 and Tmax / Tini>1.5 is satisfied (S22: YES), the calculation device 8 determines that the reaction has progressed in the working fluid in the reaction vessel 2, and proceeds to step S9 in FIG. 5.

[0093] If Pmax does not satisfy Pmax > Pini + 0.5 MPa in step S21 (S21: NO), the pulse energy is increased so that the discharge energy increases (S23). As an example, the pulse width and / or maximum power value of the applied pulse is set so that the discharge energy increases by a first value. The calculation device 8 again starts discharge by the discharge generator 10 (S24) and acquires reaction information (S25). The calculation device 8 performs an analysis of the discharge power based on the discharge information and calculates the discharge energy (S26). The calculation device 8 determines whether Pmax satisfies Pmax > Pini + 0.5 MPa based on the reaction information acquired in step S25 (S27). If Pmax does not satisfy Pmax > Pini + 0.5 MPa (S27: NO), the process returns to step S23 and the pulse energy is increased again.

[0094] In step S27, if Pmax satisfies Pmax > Pini + 0.5 MPa (S27: YES), the calculation device 8 determines whether at least one of Pmax / Pini > 1.5 and Tmax / Tini > 1.5 is true based on the reaction information acquired in step S25 (S28).

[0095] If at least one of Pmax / Pini>1.5 and Tmax / Tini>1.5 is satisfied (S28: YES), the calculation device 8 determines that the reaction has progressed in the working fluid in the reaction vessel 2, and proceeds to step S9 in FIG. 5.

[0096] If neither Pmax / Pini > 1.5 nor Tmax / Tini > 1.5 is satisfied in step S22 or step S28 (S22: NO, S28: NO), the pulse energy is increased to increase the discharge energy (S29). As an example, the pulse width and / or maximum power value of the applied pulse is set so that the discharge energy is increased by a second value smaller than the first value. The second value may be set to, for example, one-fifth of the first value. The calculation device 8 again starts discharge by the discharge generator 10 (S30) and acquires reaction information (S31). The calculation device 8 analyzes the discharge power based on the discharge information and calculates the discharge energy (S32). Based on the reaction information acquired in step S31, the calculation device 8 determines whether at least one of Pmax / Pini > 1.5 and Tmax / Tini > 1.5 is satisfied (S33). If neither Pmax / Pini>1.5 nor Tmax / Tini>1.5 is satisfied (S33: NO), the process returns to step S29, and the pulse energy is increased again.

[0097] If at least one of Pmax / Pini>1.5 and Tmax / Tini>1.5 is satisfied (S33: YES), the calculation device 8 determines that the reaction has progressed in the working fluid in the reaction vessel 2, and proceeds to step S9 in FIG. 5.

[0098] In step S8, the minimum pulse energy required for the reaction to proceed in the working medium in the reaction vessel 2 is determined.

[0099] As described above, the computing device 8 analyzes the discharge power (S7, S26, S32).

[0100] Next, an example of the analysis of discharge power in steps S7, S26, and S32 will be described with reference to Fig. 7. Fig. 7 is a flowchart of an example of the analysis of discharge power.

[0101] First, discharge information is acquired (S41). The calculation device 8 can receive discharge information indicating the voltage and current of the discharge circuit 3 from the discharge measurement device 6.

[0102] Next, the calculation device 8 determines the discharge period during which the discharge is occurring based on the time change in the voltage and current between the first electrode 31 and the second electrode 32 that accompanies the discharge that occurs when pulse energy is supplied from the capacitor 41 to the first electrode 31 and the second electrode 32 that are placed in the reaction vessel 2 containing the working medium (S42).

[0103] 8 is a graph showing the time change of the voltage (voltage of the discharge circuit 3) accompanying the discharge. FIG. 9 is a graph showing the time change of the current (current of the discharge circuit 3) accompanying the discharge. In the time change of the voltage shown in FIG. 8, the first time when the voltage drops from the first peak is called t １ In the time variation of the current shown in FIG. 9, the second time at the peak of the current is t ２ The third time when the current becomes 0 after the peak is t ３ The discharge period is the first time t １ From the third time t ３ This is the period until

[0104] The calculation device 8 determines, from the discharge period based on the time changes in the voltage and current of the discharge circuit 3, an AC discharge period in which AC discharge is occurring and a DC discharge period in which DC discharge is occurring (S43). １ From the second time t ２ The DC discharge period is the period from the second time t ２ From the third time t ３ This is the period until

[0105] The calculation device 8 determines the AC discharge energy (S44). In this embodiment, the calculation device 8 determines the AC discharge energy during the AC discharge period based on the relationship between the voltage and current obtained from the time changes of the voltage and current of the discharge circuit 3. Fig. 10 is a graph showing the relationship between the voltage and current associated with discharge. When the voltage associated with discharge is V, the current is I, and the time is t, the power is expressed as f ＡＣ (I, V, t). The AC discharge energy is E ＡＣ Then, E ＡＣ is expressed by the following equation (1).

[0106]

[0107] The calculation device 8 determines the DC discharge energy (S45). In this embodiment, the calculation device 8 determines the DC discharge energy during the DC discharge period based on the change over time of the power calculated from the voltage and current of the discharge circuit 3. Fig. 11 is a graph showing the change over time of the power due to the discharge. When the voltage due to the discharge is V, the current is I, and the time is t, the power is expressed as f ＤＣ (I x V, t). DC discharge energy is E ＤＣ Then, E ＤＣ is expressed by the following equation (2).

[0108]

[0109] The calculation device 8 adds up the AC discharge energy and the DC discharge energy (S46). The sum of the AC discharge energy and the DC discharge energy is the discharge energy.

[0110] If the calculation device 8 determines that a reaction is progressing in the working medium in the reaction vessel 2 (S22: YES, S28: YES, S33: YES), it determines the minimum discharge energy (S9) and the reaction amount (S10).

[0111] In determining the minimum discharge energy (S9), the calculation device 8 determines the value of the discharge energy when the reaction of the working medium progresses based on the time changes in the voltage and current between the first electrode 31 and the second electrode 32 due to discharge, or the capacitance and charging voltage of the capacitor 41. In particular, in this embodiment, the minimum value of the discharge energy when the reaction of the working medium progresses is determined. Hereinafter, the minimum discharge energy at which the reaction of the working medium progresses may be referred to as the minimum discharge energy. The minimum discharge energy may represent the critical energy of the working medium. A high critical energy of the working medium means that the working medium is less likely to react, and a low critical energy of the working medium means that the working medium is more likely to react. The critical energy may be (1) the minimum value of energy when a reaction of the working medium occurs due to discharge, or (2) an intermediate value between the minimum value of energy when a reaction of the working medium occurs due to discharge and the maximum value of energy when a reaction of the working medium does not occur due to discharge.

[0112] As described above, step S7 determines the minimum value of discharge energy at which a reaction proceeds in the working fluid in the reaction vessel 2 and the maximum value of discharge energy at which a reaction does not proceed in the working fluid in the reaction vessel 2. Therefore, the calculation device 8 can determine the minimum discharge energy.

[0113] In determining the reaction amount (S10), the calculation device 8 determines the reaction amount of the working medium based on the change in at least one of the temperature inside the reaction vessel 2 or the pressure inside the reaction vessel 2 during a predetermined period from the occurrence of discharge due to the supply of pulse energy from the capacitor 41 to the first electrode 31 and the second electrode 32 placed inside the reaction vessel 2 containing the working medium.

[0114] As an example, the reaction amount can be calculated as the difference between the number of molecules of the working medium 200 calculated from the pressure in the reaction vessel a predetermined time after the occurrence of the discharge and the temperature in the reaction vessel a predetermined time after the occurrence of the discharge, and the number of molecules of the working medium 200 calculated from the pressure (initial pressure Pini [MPa]) or temperature (initial temperature Tini [K]) in the reaction vessel before the occurrence of the discharge.

[0115] Next, the result of the evaluation of the reactivity of the working fluid is output (S11). The evaluation result includes the minimum discharge energy and the reaction amount, and may also include the maximum pressure Pmax as necessary. The output may include displaying the result on a screen such as a display, recording the result in a database or storage, transmitting the result to an external device via wireless or wired communication, etc.

[0116] The above-described working fluid evaluation method can determine the value of discharge energy (particularly, the minimum discharge energy) at which the reaction of the working fluid proceeds. The minimum discharge energy can represent the critical energy of the working fluid. The higher the critical energy of the working fluid, the less reactive the working fluid becomes (i.e., the less likely the disproportionation reaction proceeds). The lower the critical energy of the working fluid, the more reactive the working fluid becomes (i.e., the more likely the disproportionation reaction proceeds). Therefore, the minimum discharge energy can quantitatively evaluate the reactivity (stability) of the working fluid.

[0117] By performing the evaluation method on a plurality of working fluids, it is possible to build a database showing the evaluation results of the reactivity of the working fluids. For example, by using the database showing the evaluation results of the reactivity of the working fluids, it is possible to extract a working fluid that satisfies a desired minimum discharge energy condition, or to extract evaluation results (e.g., minimum discharge energy, reaction amount, maximum pressure) for a desired working fluid.

[0118] Next, a description will be given of a method for evaluating the risk of damage to the refrigeration cycle circuit 102 using the results of the evaluation of the reactivity of the working medium. In the evaluation of the risk of damage to the refrigeration cycle circuit 102, it is mainly evaluated whether or not there is a possibility that the refrigeration cycle circuit 102 will be damaged when the reaction of the working medium 200 progresses in the refrigeration cycle circuit 102.

[0119] FIG. 12 is a flowchart of an example of a method for evaluating the risk of damage to the refrigeration cycle circuit 102.

[0120] First, the working medium 200 to be used in the refrigeration cycle circuit 102 is determined (S51). As an example, the composition of the working medium 200 is determined. Then, the result of the evaluation of the reactivity of the working medium 200 is obtained. Hereinafter, the minimum discharge energy included in the result of the evaluation of the reactivity of the working medium 200 is used as the critical energy of the working medium 200.

[0121] Next, the quenching distance of the working medium 200 determined in step S51 is determined (S52). The quenching distance is determined based on the composition of the working medium 200. The quenching distance of the working medium 200 can be determined from a database of working mediums or by testing.

[0122] Next, the configuration of the power source of the compressor 104 of the refrigeration cycle circuit 102 is determined (S53). The configuration of the power source of the compressor 104 corresponds to the configuration of the drive circuit 1031. As an example, the power source is either an inverter type or a constant speed type. If the power source is an inverter type, the configuration of the power source may include a reference frequency and voltage of the inverter. If the power source is a constant speed type, the configuration of the power source may include a fixed frequency and voltage. The configuration of the power source may include a control method such as PAM or PWM, as necessary.

[0123] Next, the withstand pressure of the compressor 104 is determined (S54). To determine the withstand pressure of the compressor 104, an internal region of the compressor 104 is identified in which an open space equal to or smaller than the quenching distance determined in step S52 is located near a discharge risk portion. The discharge risk portion refers to a region in which a potential difference occurs across a minute gap of 1 mm or less. The withstand pressure of target components, such as the partition wall of the sealed container and the crankshaft, located around the internal region is determined as the withstand pressure of the compressor 104. In this embodiment, the lowest withstand pressure of the target components is determined as the minimum withstand pressure of the compressor 104. For example, if the insulating coating above the coil of the stator 1042b of the electric motor 1042 is damaged within the compressor 104, a potential difference may occur across a gap of 1 mm or less, resulting in a discharge space equal to or smaller than the quenching distance above. In such a case, the area around the coil of the compressor 104 is identified as the internal region. Therefore, the withstand pressure around the coil of the compressor 104 is determined as the minimum withstand pressure (also called the withstand pressure limit) of the compressor 104 .

[0124] If the compressor 104 is equipped with a control valve (S55: YES), the critical energy condition is relaxed (S56). The control valve is set to open when the pressure inside the sealed container 1040 of the compressor 104 reaches or exceeds a threshold. Such a control valve is also called a pressure relief valve. This can relax the increase in pressure inside the compressor 104. If the compressor 104 has a control valve, it is preferable to relax the critical energy condition of the working medium. Here, the relaxation of the critical energy condition is performed by multiplying the critical energy of the working medium by a coefficient equal to or greater than a predetermined value. The predetermined value is, for example, 1.5. The specific value of the coefficient is determined by the pressure loss from the internal region of the compressor 104 to the control valve.

[0125] Next, pulse energy is estimated (S57). Pulse energy is pulse energy that may be unintentionally generated in the power source of the compressor 104. Estimating pulse energy includes determining the power input to the compressor 104 based on the configuration of the power source (drive circuit 1031) of the compressor 104 of the refrigeration cycle apparatus 100, and determining the width of the applied pulse based on the power and the configuration of the power source. For example, the maximum and minimum values ​​of the pulse width are determined based on the configuration of the electric motor 1042. The optimal pulse width for the configuration of the electric motor 1042 can be determined based on the maximum and minimum values ​​of the pulse width. For example, the optimal pulse width may be an intermediate value between the maximum and minimum values. The maximum power and maximum voltage input to the compressor 104 are determined based on the configuration of the drive circuit 1031, and the maximum current input to the compressor 104 is determined based on the maximum power and maximum voltage input to the compressor 104. The maximum value of pulse energy can be determined based on the maximum current input to the compressor 104. In this way, the maximum power value and pulse width of the applied pulse can be determined based on the power source of the compressor 104.

[0126] Next, a risk of damage is evaluated (S58). The risk of damage is evaluated by comparing the withstand pressure of the compressor 104 with the pressure of the working medium 200. In this embodiment, the risk of damage is evaluated by comparing the minimum withstand pressure of the compressor 104 with the maximum pressure of the working medium 200. The maximum pressure of the working medium 200 depends on whether a reaction of the working medium 200 proceeds. Whether a reaction of the working medium 200 proceeds is determined by comparing the discharge energy based on the pulse energy estimated in step S57 with the critical energy of the working medium 200. The discharge energy based on the pulse energy is determined based on the maximum power value and pulse width of the applied pulse, which determine the pulse energy. If the discharge energy exceeds the critical energy, there is a high possibility that a reaction of the working medium 200 will proceed. Therefore, the maximum pressure of the working medium 200 is the maximum pressure obtained from the result of the evaluation of the reactivity of the working medium 200, i.e., the maximum pressure when a reaction of the working medium 200 proceeds. If the minimum withstand pressure of the compressor 104 is greater than the maximum pressure of the working medium 200, the risk of damage is evaluated as low. If the minimum withstand pressure of the compressor 104 is less than the maximum pressure of the working medium 200, the risk of damage is evaluated as high.

[0127] Next, the result of the assessment of the risk of damage to the refrigeration cycle circuit 102 is output (S59). The output of the assessment result may include displaying the result on a screen such as a display, recording the result in a database or storage, transmitting the result to an external device via wireless or wired communication, etc.

[0128] Next, a method for determining the composition of the working medium 200 used in the refrigeration cycle circuit 102 using the results of the evaluation of the reactivity of the working medium will be described.

[0129] FIG. 13 is a flowchart of an example of a method for determining the composition of the working medium 200.

[0130] First, the structure of the refrigeration cycle circuit 102 is determined (S61). The structure of the refrigeration cycle circuit 102 includes the structures of one or more components included in the refrigeration cycle circuit 102. Examples of the one or more components may include the compressor 104, the first heat exchanger 105, the expansion valve 106, the second heat exchanger 107, the four-way valve 108, and the piping 109, as shown in FIG. 1 . As an example, the structure of the piping 109 may include the diameter, length, and thickness of the piping 109, the method of joining the piping 109 and the compressor 104 (the discharge pipe 1040b), and the like. The structure of the compressor 104 may include the size of the compressor 104 (the size of the sealed container 1040), the position of the coil of the stator 1042b of the electric motor 1042 within the sealed container 1040, and the like.

[0131] Next, the state around the coil of the compressor 104 is determined (S62). The state around the coil of the compressor 104 particularly includes the portion of the coil that may come into contact with the working medium 200. The state around the coil of the compressor 104 may include the flow of the working medium 200 around the coil or wetting of the coil. The state around the coil is obtained by analyzing the structure of the refrigeration cycle circuit 102 determined in step S61. For example, computational fluid dynamics (CFD) analysis, a digital twin model, or a trained model created using data obtained by CFD analysis or a digital twin model can be used to analyze the structure of the refrigeration cycle circuit 102.

[0132] Next, an energy correction coefficient is determined (S63). The energy correction coefficient is used to correct the maximum energy in the compressor 104. The energy correction coefficient is determined based on the condition around the coil of the compressor 104. The correction coefficient is given, for example, as a positive number. As an example, the faster the flow of the working medium 200 around the coil, the smaller the correction coefficient is set, and the slower the flow of the working medium 200 around the coil, the larger the correction coefficient is set. This is because the high-temperature area near the discharge location is quickly cooled by forced convection. The greater the wetting of the coil with the non-working medium, such as refrigeration oil, the smaller the correction coefficient is set, and the smaller the wetting of the coil with the non-working medium, the larger the correction coefficient is set. This is because the high-temperature area near the discharge location is quickly cooled by evaporation of the non-working medium, which is less likely to generate active chemical species.

[0133] Next, the configuration of the power source of the compressor 104 of the refrigeration cycle circuit 102 is determined (S64). The configuration of the power source of the compressor 104 corresponds to the configuration of the drive circuit 1031. As an example, the power source is either an inverter or a rated machine. If the power source is an inverter, the configuration of the power source may include the reference frequency and voltage of the inverter. The reference frequency is several kHz or more. If the power source is a rated machine, the configuration of the power source may include the frequency and voltage of the rated machine. The configuration of the power source may include a control method such as PAM or PWM, as necessary.

[0134] Next, the maximum energy in the compressor 104 is determined (S65). The maximum energy in the compressor 104 is, for example, the maximum energy that can be generated around the coil of the compressor 104. The maximum energy that can be generated around the coil of the compressor 104 is obtained by analyzing the configuration of the power source of the compressor 104 determined in step S64. For example, a finite element method (FEM) analysis, a digital twin model, or a trained model created using data obtained by the FEM analysis or the digital twin model can be used to analyze the configuration of the power source of the compressor 104.

[0135] Next, the energy is corrected (S66) by multiplying the maximum energy determined in step S65 by the correction coefficient determined in step S63.

[0136] Next, the composition of the working medium 200 is determined (S67). In the refrigeration cycle circuit 102, it is preferable that the reaction of the working medium 200 does not proceed around the coil of the compressor 104. Therefore, it is preferable that the composition of the working medium 200 used in the refrigeration cycle circuit 102 has a critical energy greater than the energy corrected in step S66. Determining the composition of the working medium 200 includes extracting, from a database showing the results of the evaluation of the reactivity of the working medium 200, working mediums 200 having a critical energy greater than the energy corrected in step S66.

[0137] Next, the result of determining the composition of the working medium 200 in step S67 is output (S68). The output of the result of determining the composition of the working medium 200 may include displaying it on a screen such as a display, recording it in a database or storage, transmitting it to an external device via wireless or wired communication, etc.

[0138] In this way, it is possible to determine the composition of the working medium 200 that is unlikely to undergo a reaction in the refrigeration cycle circuit 102.

[0139] Next, a method for determining the configuration of the refrigeration cycle circuit 102 using the results of the evaluation of the reactivity of the working medium will be described.

[0140] FIG. 14 is a flowchart of an example of a method for determining the configuration of the refrigeration cycle circuit 102.

[0141] Step S71 in FIG. 14 is the same as step S61 in FIG.

[0142] Next, the state around the coil of the compressor 104 is determined (S72). The state around the coil of the compressor 104 particularly includes multiple regions of the coil that may come into contact with the working medium 200. The state around the coil includes the states of multiple regions around the coil. Each of the states of the multiple regions around the coil may include the flow of the working medium 200 or wetting of the coil. The state around the coil is obtained by analyzing the structure of the refrigeration cycle circuit 102 determined in step S71. For example, computational fluid dynamics (CFD) analysis, a digital twin model, or a trained model created using data obtained by CFD analysis or a digital twin model can be used to analyze the structure of the refrigeration cycle circuit 102.

[0143] Next, an energy correction coefficient is determined (S73). The energy correction coefficient is used to correct the maximum energy in the compressor 104. The energy correction coefficient is determined for each of a plurality of regions around the coil of the compressor 104. The energy correction coefficient is determined based on each region around the coil of the compressor 104. The correction coefficient is given, for example, as a positive number. As an example, the faster the flow of the working medium 200 around the coil, the larger the correction coefficient is set, and the slower the flow of the working medium 200 around the coil, the smaller the correction coefficient is set. The more wet the coil, the larger the correction coefficient is set, and the less wet the coil, the smaller the correction coefficient is set.

[0144] The next step S74 is the same as step S64 in FIG.

[0145] Next, the maximum energy in the compressor 104 is determined (S75). The maximum energy in the compressor 104 is, for example, the maximum energy that can be generated in each of a plurality of regions around the coil of the compressor 104. The maximum energy that can be generated in each of a plurality of regions around the coil of the compressor 104 is obtained by analyzing the configuration of the power source of the compressor 104 determined in step S74. For example, the analysis of the configuration of the power source of the compressor 104 can be performed using finite element method (FEM) analysis, a digital twin model, or a trained model created using data obtained by FEM analysis or a digital twin model.

[0146] Next, energy correction is performed (S76). For each of the multiple regions around the coil of the compressor 104, the energy correction is performed by multiplying the maximum energy determined in step S76 by the correction coefficient determined in step S73. As a result, the corrected maximum energy for each of the multiple regions around the coil of the compressor 104 is obtained.

[0147] Next, the critical energy of the working medium 200 used in the refrigeration cycle circuit 102 is determined (S77). As an example, the composition of the working medium 200 is determined, and the minimum discharge energy is obtained as the critical energy of the working medium 200 from the results of evaluating the reactivity of the working medium 200.

[0148] Next, the refrigeration cycle circuit 102 is evaluated (S78). The evaluation of the refrigeration cycle circuit 102 is performed by comparing the corrected maximum energy of each of the multiple regions around the coil of the compressor 104 with the critical energy of the working medium 200. If the corrected maximum energy is greater than the critical energy, it is evaluated that there is a high possibility that the reaction of the working medium 200 will proceed. If the corrected maximum energy is smaller than the critical energy, it is evaluated that there is a low possibility that the reaction of the working medium 200 will proceed.

[0149] Next, the evaluation result of the refrigeration cycle circuit 102 is output (S79). The output of the evaluation result may include displaying the result on a screen such as a display, recording the result in a database or storage, transmitting the result to an external device via wireless or wired communication, etc. As an example, the evaluation result of the refrigeration cycle circuit 102 may be displayed using an image of the inside of the compressor 104. In the image of the compressor 104, information such as the state (flow of the working medium 200 or wetting of the coil), the corrected maximum energy, and the evaluation result (degree of possibility that the reaction of the working medium 200 will proceed) may be displayed for each of a plurality of regions using text, color, graphics, etc.

[0150] Based on the results of the evaluation of the refrigeration cycle circuit 102, the configuration of the refrigeration cycle circuit 102 can be determined so as to reduce the area evaluated as having a high possibility of the reaction of the working medium 200 progressing.

[0151] [1.2 Effects, etc.] The evaluation system 1 described above includes a reaction vessel 2 in which a first electrode 31 and a second electrode 32 are disposed and which contains a working medium 200, a capacitor 41 connected at both ends to each of the first electrode 31 and the second electrode 32 and to which a predetermined DC voltage greater than 2 kV is applied, and a semiconductor switch 42 connected between the capacitor 41 and the first electrode 31 and for applying pulse energy to the first electrode 31 and the second electrode 32 based on the voltage across the capacitor 41. This configuration enables quantitative evaluation of the reactivity of the working medium.

[0152] In the evaluation system 1, the distance D between the first electrode 31 and the second electrode 32 is 30 μm or more. This configuration can facilitate the generation of discharge.

[0153] In the evaluation system 1, the first electrode 31 and the second electrode 32 are rod-shaped, and the central axes C31, C32 of the first electrode 31 and the second electrode 32 do not coincide with each other. This configuration can improve the stability of discharge generation.

[0154] In the evaluation system 1, the central axes C31, C32 of the first electrode 31 and the second electrode 32 are parallel to each other, the first electrode 31 and the second electrode 32 face each other in a direction perpendicular to the central axes C31, C32 of the first electrode 31 and the second electrode 32, and the lengths of the portions 31 a, 32 a of the first electrode 31 and the second electrode 32 facing each other in the direction perpendicular to the central axes C31, C32 of the first electrode 31 and the second electrode 32 are 0.5 mm or more. This configuration can improve the stability of discharge generation.

[0155] The above-described evaluation method is a method for evaluating the reaction of a working medium, which is executed in an evaluation system 1. The evaluation system 1 includes a reaction vessel 2 having a first electrode 31 and a second electrode 32 disposed therein and containing a working medium 200, a capacitor 41 connected to each of the first electrode 31 and the second electrode 32 at both ends thereof and to which a predetermined DC voltage is applied, a semiconductor switch 42 connected between the capacitor 41 and the first electrode 31 for applying pulse energy to the first electrode 31 and the second electrode 32 based on the voltage across the capacitor 41, and a computing device 8. The evaluation method is executed by the computing device 8 and includes determining (S9) a value of discharge energy as the reaction of the working medium 200 progresses, based on changes over time in the voltage and current between the first electrode 31 and the second electrode 32 that accompany discharges generated by applying pulse energy to the first electrode 31 and the second electrode 32. This configuration enables quantitative evaluation of the reactivity of the working medium 200.

[0156] The evaluation method further includes calculating (S8) a degree of progress of the reaction of the working medium 200 based on a change in at least one of the temperature in the reaction vessel 2 and the pressure in the reaction vessel 2 during a predetermined period from the occurrence of the discharge. This configuration enables quantitative evaluation of the reactivity of the working medium 200.

[0157] The evaluation method described above includes calculating the degree of progress of the reaction of the working medium 200 based on a change in at least one of the temperature inside the reaction vessel 2 and the pressure inside the reaction vessel 2 during a predetermined period from the occurrence of discharge caused by supplying pulse energy from the capacitor 41 to the first electrode 31 and the second electrode 32 disposed in the reaction vessel 2 containing the working medium 200 (S8), and determining the value of discharge energy when the reaction of the working medium 200 has progressed based on the time changes in the voltage and current between the first electrode 31 and the second electrode 32 due to the discharge (S9). This configuration enables quantitative evaluation of the reactivity of the working medium 200.

[0158] The evaluation method further includes comparing the pressure in the reaction vessel 2 for a predetermined period with the withstand pressure of one or more components, including the compressor 104, of the refrigeration cycle device 100 that uses the working medium 200 to evaluate the possibility of damage to the refrigeration cycle device 100 (S58), and, if it is evaluated that there is a possibility of damage to the refrigeration cycle device 100, extracting (S67) a working medium 200 that has a different composition from the evaluated working medium 200 and a higher critical energy than the evaluated working medium 200. This configuration makes it possible to evaluate the risk of damage to the refrigeration cycle circuit 102.

[0159] The evaluation method further includes determining (S57) the electric power input to the compressor 104 based on the configuration of the power source (drive circuit 1031) of the compressor 104 of the refrigeration cycle device 100 that uses the working medium 200, and determining (S57) the width of the applied pulse based on the electric power and the configuration of the power source. This configuration enables improved accuracy in evaluating the risk of damage to the refrigeration cycle circuit 102.

[0160] In the evaluation method, the power source (drive circuit 1031) is either an inverter type or a constant speed type. This configuration enables the accuracy of evaluation of the risk of damage to the refrigeration cycle circuit 102 to be improved.

[0161] The evaluation method further includes identifying an internal region in the compressor (104) where a potential difference occurs across a gap equal to or smaller than the quenching distance of the working medium 200 (S54), and determining the withstand pressure in the internal region as the withstand pressure of the compressor (S54). This configuration enables improved accuracy in evaluating the risk of damage to the refrigeration cycle circuit 102.

[0162] In the evaluation method, if the temperature or pressure in the reaction vessel 2 becomes 1.5 times or more of the temperature before the discharge occurs within a predetermined period, it is determined that the reaction of the working medium 200 has progressed (S8). This configuration enables improvement in the accuracy of quantitative evaluation of the reactivity of the working medium 200.

[0163] The evaluation method described above includes determining a discharge period during which discharge occurs based on time changes in voltage and current between the first electrode 31 and the second electrode 32 associated with discharge generated at the first electrode 31 and the second electrode 32 disposed in the reaction vessel 2 containing the working medium 200 (S42), determining an AC discharge period during which AC discharge occurs and a DC discharge period during which DC discharge occurs from the discharge period based on time changes in voltage and current (S43), calculating AC discharge energy during the AC discharge period based on the relationship between voltage and current obtained from time changes in voltage and current (S44), calculating DC discharge energy during the DC discharge period based on time changes in power obtained from time changes in voltage and current (S45), and calculating a value of discharge energy when the reaction of the working medium 200 progresses from the AC discharge energy and the DC discharge energy (S46). This configuration enables quantitative evaluation of the reactivity of the working medium 200.

[0164] The evaluation method described in the embodiment is realized by using the calculation device 8. That is, the evaluation method performed by the calculation device 8 can be realized by the calculation device 8 executing a program. This program is a computer program for causing a computer system such as the calculation device 8 to execute the evaluation method. This configuration enables quantitative evaluation of the reactivity of the working medium 200.

[0165] [2. Modifications] The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiments are listed below. The modifications described below can be applied in appropriate combinations.

[0166] In one modified example, the value of the discharge energy when the reaction of the working medium progresses may be determined based on the capacitance and charging voltage of the capacitor 41. As an example, the energy decreased in the capacitor 41 can be determined as the discharge energy from the capacitance and the change in the charging voltage accompanying the occurrence of discharge. In this way, the value of the discharge energy when the reaction of the working medium progresses may be determined based on the time changes in the voltage and current between the first electrode 31 and the second electrode 32 accompanying the discharge, or the capacitance and charging voltage of the capacitor 41.

[0167] In one modified example, in the evaluation of the risk of damage in step S58 of Fig. 12, the possibility of damage to the refrigeration cycle apparatus 100 may be evaluated by comparing the pressure inside the reaction vessel 2 for a predetermined period with the withstand pressure of one or more components, including the compressor 104, of the refrigeration cycle apparatus 100. The one or more components may include the compressor 104, the first heat exchanger 105, the expansion valve 106, the second heat exchanger 107, the four-way valve 108, and the piping 109. Here, the pressure inside the reaction vessel 2 may be the maximum pressure. The withstand pressure of the one or more components, including the compressor 104, of the refrigeration cycle apparatus 100 may be the minimum withstand pressure.

[0168] In one modified example, if the compressor 104 includes the electric motor 1042, in step S54, the withstand voltage in the area surrounding the coil of the electric motor 1042 may be determined as the withstand voltage of the compressor 104. This is because undesirable discharges tend to occur around the coil of the compressor 104. In this manner, the evaluation method may further include determining the withstand voltage in the area surrounding the coil of the electric motor 1042 as the withstand voltage of the compressor 104. This simplifies the process of determining the withstand voltage of the compressor 104. In particular, the withstand voltage in the area surrounding the coil of the electric motor 1042 may be determined as the minimum withstand voltage of the compressor 104.

[0169] In one variant, the degree of progress of the reaction of the working medium 200 may be determined based on at least one change in the temperature in the reaction vessel 2, the pressure in the reaction vessel 2, the composition of the working medium 200, or the amount of reaction products of the working medium 200 over a predetermined period of time from the occurrence of a discharge caused by supplying pulse energy from the capacitor 41 to the first electrode 31 and the second electrode 32 disposed in the reaction vessel 2 containing the working medium 200.

[0170] When the composition of the working medium 200 is used, the degree of progress of the reaction may be expressed as the degree of agreement between the composition of the working medium after a predetermined period of time from the occurrence of discharge and the composition of the working medium before the occurrence of discharge. In this case, if the degree of agreement is below 90%, it may be determined that the reaction of the working medium has progressed. In other words, if the composition of the working medium changes by more than 10% from the composition of the working medium before the occurrence of discharge within a predetermined period of time, it may be determined that the reaction of the working medium has progressed. This configuration enables improved accuracy in quantitative evaluation of the reactivity of the working medium 200.

[0171] The composition of the working medium after a predetermined period of time from the occurrence of the discharge can be determined by analyzing the composition of the gas separated from the reaction vessel 2 by gas chromatography. The composition of the working medium before the occurrence of the discharge is usually known.

[0172] When the amount of reaction products of the working medium 200 is used, the reaction rate can be taken into consideration. The reaction rate is x, and the total amount of material of the working medium before the discharge occurs is M. １ [mol], the amount of substance of the reaction product of the working fluid after a predetermined period from the occurrence of discharge is M ２ In this case, x is expressed by the following formula (3): In the following formula (3), A represents the change in the number of moles before and after the reaction when the working fluid having disproportionation reactivity is 100% reacted.

[0173]

[0174] If x≧0.1 holds, it may be determined that the reaction of the working medium has progressed. That is, if the amount of substance of the reaction product becomes 10% or more of the total amount of substance of the working medium before the discharge occurs within a predetermined period, it may be determined that the reaction of the working medium has progressed. This configuration enables improved accuracy in quantitatively evaluating the reactivity of the working medium 200.

[0175] The reaction product may include an intermediate product or a final product. The final product refers to a thermodynamically stable chemical species among the chemical species generated in the disproportionation reaction of the working fluid. Here, "thermodynamically stable" means that the type and composition of the compound do not change when exposed to a high temperature of 2000 K or higher at 1 atmosphere for a predetermined time (e.g., about 10 minutes) and then returned to room temperature and normal pressure. The intermediate product refers to a thermodynamically unstable chemical species among the chemical species generated in the disproportionation reaction of the working fluid. "Thermodynamically unstable" means that at least one of the type and composition of the compound changes when exposed to a high temperature of 2000 K or higher at 1 atmosphere. Thermodynamically unstable chemical species also include so-called metastable chemical species. In particular, the intermediate product can be said to be a chemical species among the chemical species generated in the disproportionation reaction of the working fluid that may exist with a lifetime of 1 ms or more but that can decompose at high temperatures (e.g., 2000 K or higher) to produce the final product. Naturally, such intermediate products do not include the final product. The lifespan here is measured under an environment equivalent to the inside of a refrigeration cycle circuit, for example, at a maximum temperature of 500 K and a maximum pressure of 6 MPa.

[0176] For example, when the working fluid 200 contains an ethylene-based fluoroolefin as a refrigerant component, the intermediate products include carbenes, carbene inserts (compounds produced by the insertion reaction of carbene), tetrafluoroethylene, perfluoroolefins, and fluorobenzene. The final products include soot, hydrogen fluoride, and tetrafluoromethane.

[0177] In one variant, the reaction amount of the working medium 200 may be determined based on at least one change in the temperature in the reaction vessel 2, the pressure in the reaction vessel 2, the composition of the working medium 200, or the amount of reaction products of the working medium 200 during a predetermined period from the occurrence of discharge due to the supply of pulse energy from the capacitor 41 to the first electrode 31 and the second electrode 32 placed in the reaction vessel 2 filled with the working medium 200 for the refrigeration cycle device 100.

[0178] When the composition of the working medium 200 is used, the reaction amount may be expressed as the degree of change (degree of discrepancy) between the composition of the working medium after a predetermined period of time from the occurrence of discharge and the composition of the working medium before the occurrence of discharge.

[0179] When the amount of the reaction product of the working medium 200 is used, the reaction amount may be calculated based on the reaction rate x expressed by the above formula (3).

[0180] The amount of the reaction product can be determined by measuring the amount of the reaction product separated from the reaction vessel 2 by gas chromatography. The amount of the reaction product can be determined by measuring using a particle counter. When a discharge occurs, relatively stable compounds are generated from the working fluid 200, and these compounds may circulate as insoluble components within the refrigeration cycle circuit 102 together with the working fluid 200. For example, when the working fluid 200 contains an ethylene-based fluoroolefin, soot or hydrogen fluoride (HF) is generated as an insoluble component. Such unwanted components are examples of reaction products generated from the working fluid 200 by a disproportionation reaction. An increase in such insoluble components can be a factor in a decrease in the permeability of the working fluid 200. In other words, by focusing on the permeability of the working fluid 200, the increase in insoluble components can be quantitatively evaluated, thereby determining the amount of the reaction product.

[0181] In one variant, the reaction vessel 2 does not necessarily have to have the control valve 22. The reaction vessel 2 does not necessarily have to have the temperature controller 23.

[0182] In one modified example, the shapes of the first electrode 31 and the second electrode 32 of the discharge circuit 3 are not particularly limited. The first electrode 31 and the second electrode 32 may be plate-shaped instead of rod-shaped. The first electrode 31 and the second electrode 32 may be arranged so that the central axes C31, C32 of the first electrode 31 and the second electrode 32 coincide with each other. In this case, the tips of the first electrode 31 and the second electrode 32 face each other in the direction of the central axes C31, C32. The central axes C31, C32 of the first electrode 31 and the second electrode 32 may be skewed. In this case, as long as one of the first electrode 31 and the second electrode 32 is plate-shaped and the other is rod-shaped, the length g of the opposing portion of the first electrode 31 and the second electrode 32 can be set to a desired length.

[0183] In one modified example, the capacitor 41, the semiconductor switch 42, the current limiter 43, and the pulsed power supply 44 in the drive circuit 4 are not limited to the above example and may be changed as appropriate. Fig. 3 is merely one example of the circuit of the discharge generator 10, and the capacitor 41, the semiconductor switch 42, the current limiter 43, and the pulsed power supply 44 can be replaced with equivalent circuit configurations, etc.

[0184] In one modified example, the reaction measurement device 5 is located inside the reaction vessel 2, but may be located outside the reaction vessel 2 as long as it can measure the pressure or temperature inside the reaction vessel 2.

[0185] In one modified example, the position of the discharge measuring device 6 is not limited to the position shown in FIG. 3, and is not particularly limited as long as it can measure the voltage and current of the discharge circuit 3.

[0186] In one modification, the DC power supply 7 is not particularly limited in configuration or type as long as it can output a predetermined DC voltage.

[0187] In one modified example, the evaluation system 1 does not necessarily have to include the DC power supply 7 and the computing device 8 .

[0188] In one modified example, the object to be evaluated by the evaluation system 1 is not limited to a working medium. The evaluation system 1 can be used to evaluate a reaction that occurs when a target object is subjected to discharge energy. The target object is not particularly limited as long as it is an object that undergoes a reaction when exposed to discharge energy. As an example, the target object may be a decomposable gas. For example, the target object may be ethylene, propylene, methane, carbon monoxide, or hydrogen peroxide. The target object may also be a gaseous object under high pressure to normal pressure. The working medium in which the above-described disproportionation reaction can occur is an example of such a target object.

[0189] Next, a description will be given of an example of an evaluation test of a target object using the evaluation system 1. FIG.

[0190] First, the conditions for the evaluation test are set (S81). In setting the conditions for the evaluation test, the target object is first determined. Next, the discharge conditions and environmental conditions (pressure or temperature conditions inside the reaction vessel 2) are determined taking into consideration the expected usage conditions of the target object, etc.

[0191] Next, the target objects are loaded into the reaction vessel 2 (S82).

[0192] The pressure and temperature inside the reaction vessel 2 filled with the target object are set (S83). Here, the computing device 8 controls the temperature controller 23 based on the temperature conditions inside the reaction vessel 2 to set the temperature inside the reaction vessel 2. If there is a pressure requirement inside the reaction vessel 2, the vessel body 21 and the control valve 22 of the reaction vessel 2 can be selected to meet the pressure requirement inside the reaction vessel 2.

[0193] The pulse energy is set based on the discharge conditions (S84). The pulse energy setting mainly includes the setting of the pulse width and maximum power value of the applied pulse. The setting of the pulse width and maximum power value of the applied pulse includes the setting of the drive circuit 4 and the DC power supply 7 (see step S4).

[0194] After the pressure and temperature settings (S83) and pulse energy settings (S84) are completed, discharge is started by the discharge generator 10 (S85). The computing device 8 controls the pulse power supply 44 to output a pulse signal to the semiconductor switch 42, which in turn outputs an application pulse to the discharge circuit 3 and applies pulse energy.

[0195] The reaction information and discharge information are acquired (S86). The calculation device 8 can receive reaction information indicating at least one of the pressure and temperature inside the reaction vessel 2 from the reaction measurement device 5, and can receive discharge information indicating the voltage and current of the discharge circuit 3 from the discharge measurement device 6.

[0196] An analysis of the discharge power is performed (S87). The calculation device 8 performs an analysis of the discharge power based on the discharge information, and can calculate the discharge energy under the conditions of the evaluation test. Since the discharge information includes the change in voltage over time and the change in current over time, the discharge time can be determined based on the change in current over time. The discharge energy can be determined by integrating the power calculated from the voltage and current over the discharge time.

[0197] It is determined whether a reaction has occurred in the target object in the reaction vessel 2 (S88). The calculation device 8 determines whether a reaction has occurred in the target object in the reaction vessel 2 based on the reaction information. When a reaction of the target object occurs in the reaction vessel 2, the pressure and temperature inside the reaction vessel 2 tend to increase. As an example, the calculation device 8 compares the pressure and temperature inside the reaction vessel 2 with their respective threshold values. If the pressure and temperature inside the reaction vessel 2 exceed their respective threshold values, the calculation device 8 determines that a reaction has occurred in the target object in the reaction vessel 2.

[0198] If it is determined that no reaction has occurred in the target object in the reaction vessel 2 (S88: NO), the process returns to step S84. The pulse energy is reset (S84), discharge is started (S85), reaction information and discharge information are acquired (S86), an analysis of the discharge power is performed (S87), and it is again determined whether or not a reaction has occurred in the target object in the reaction vessel 2 (S88).

[0199] If it is determined that a reaction is occurring in the target object in the reaction vessel 2 (S88: YES), the evaluation test results are output (S89). The evaluation test results may include the minimum discharge energy at which the reaction of the target object progressed. The minimum discharge energy may represent the critical energy of the target object. A high critical energy of the target object means that the target object is less likely to react, while a low critical energy of the target object means that the target object is more likely to react. The critical energy may be (1) the minimum value of energy when a reaction of the target object occurs due to discharge, or (2) an intermediate value between the minimum value of energy when a reaction of the target object occurs due to discharge and the maximum value of energy when a reaction of the target object does not occur due to discharge. Output of the evaluation test results may include displaying on a screen such as a display, recording in a database or storage, transmitting to an external device via wireless or wired communication, etc.

[0200] In the evaluation test, by gradually increasing the pulse width and maximum power value of the applied pulse, which determine the pulse energy, it becomes possible to quantify the critical energy and output under instantaneous discharge conditions that react with lower energy.

[0201] The discharge generator 10 described above includes a discharge circuit 3 having a first electrode 31 and a second electrode 32, and a drive circuit 4 that generates a discharge between the first electrode 31 and the second electrode 32. The drive circuit 4 includes a capacitor 41, both ends of which are connected to the first electrode 31 and the second electrode 32, respectively, and to which a predetermined DC voltage is applied, and a semiconductor switch 42, connected between the capacitor 41 and the first electrode 31, for applying pulse energy to the discharge circuit 3 based on the voltage across the capacitor 41. This configuration improves the degree of freedom in setting the discharge conditions for causing a reaction.

[0202] In the discharge generator 10, the drive circuit 4 further includes a current limiter 43 connected between the capacitor 41 or the first electrode 31 and the semiconductor switch 42, and limiting at least one of the pulse width and the maximum power value of the applied pulse. This configuration can improve the degree of freedom in setting the discharge conditions for causing a reaction.

[0203] In the discharge generator 10, the drive circuit 4 has a pulse power supply 44 for applying a pulse signal to the semiconductor switch 42 to turn on the semiconductor switch 42. This configuration can improve the degree of freedom in setting the discharge conditions for causing a reaction.

[0204] In the discharge generator 10, the first electrode 31 and the second electrode 32 are rod-shaped, and the central axes C31, C32 of the first electrode 31 and the second electrode 32 do not coincide with each other. This configuration can improve the stability of discharge generation.

[0205] In the discharge generator 10, the central axes C31, C32 of the first electrode 31 and the second electrode 32 are parallel to each other. The first electrode 31 and the second electrode 32 face each other in a direction perpendicular to the central axes C31, C32 of the first electrode 31 and the second electrode 32. The length g of the portions of the first electrode 31 and the second electrode 32 that face each other in a direction perpendicular to the central axes C31, C32 of the first electrode 31 and the second electrode 32 is 0.5 mm or more. This configuration can improve the stability of discharge generation.

[0206] In the discharge generator 10, the distance D between the first electrode 31 and the second electrode 32 is 30 μm or more. This configuration can facilitate the generation of discharge.

[0207] In the discharge generator 10, the capacitance of the capacitor 41 is 20 pF or more and 10 mF or less. This configuration can improve the degree of freedom in setting the discharge energy for causing a reaction.

[0208] In the discharge generator 10, the current limiter 43 includes at least one of a resistor of 20 Ω or less and a reactor of 20 H or less. This configuration can improve the degree of freedom in setting the discharge energy or time for causing a reaction.

[0209] In the discharge generator 10, the conductivity of the material of the first electrode 31 and the second electrode 32 is 1×10 ７ This configuration can reduce the influence of the voltage drop at the first electrode 31 and the second electrode 32.

[0210] In the discharge generator 10, the impedance of the electric path 45 between the capacitor 41 and the discharge circuit 3 is 0.5Ω or less. This configuration can improve the degree of freedom in setting the discharge conditions for causing a reaction.

[0211] The discharge generator 10 includes a DC power supply 7 that applies a predetermined DC voltage to the capacitor 41, the predetermined DC voltage being greater than 2 kV. This configuration allows for greater flexibility in setting the discharge conditions for causing a reaction.

[0212] The evaluation system 1 described above includes a discharge generator 10, a reaction vessel 2 in which a first electrode 31 and a second electrode 32 are placed, a reaction measurement device 5 that measures the reaction in the reaction vessel 2, and a discharge measurement device 6 that measures the discharge in the discharge circuit 3. This configuration can improve the degree of freedom in setting the discharge conditions for causing a reaction.

[0213] In the evaluation system 1, the design pressure resistance of the reaction vessel 2 is 30 MPa or more. This configuration can improve the safety of the evaluation test.

[0214] In the evaluation system 1, the reaction vessel 2 has a control valve 22 that opens when the pressure inside the reaction vessel 2 reaches or exceeds two-thirds of the design pressure resistance. This configuration can improve the safety of the evaluation test.

[0215] In the evaluation system 1, the reaction measurement device 5 includes at least one of a pressure sensor that measures the pressure inside the reaction vessel 2 and a temperature sensor that measures the temperature inside the reaction vessel 2. This configuration can improve sensitivity to the reaction.

[0216] In the evaluation system 1, the pressure sensor includes a high-speed pressure gauge. This configuration can measure instantaneous pressure changes and improve the accuracy of reaction measurement.

[0217] In the evaluation system 1, the temperature sensor includes a thermocouple. This configuration can measure instantaneous temperature changes and improve the accuracy of reaction measurement.

[0218] In the evaluation system 1, the discharge measurement device 6 includes at least one of a voltage probe 61 that measures the change over time in the voltage between the first electrode 31 and the second electrode 32 of the discharge circuit 3, and a current probe 62 that measures the change over time in the current flowing between the first electrode 31 and the second electrode 32 of the discharge circuit 3. This configuration can improve sensitivity to discharge.

[0219] In the evaluation system 1, the voltage probe 61 includes a differential voltmeter with a bandwidth of 20 MHz or more. This configuration can improve the accuracy of voltage measurement.

[0220] In the evaluation system 1, the current probe 62 includes a non-contact ammeter with a bandwidth of 20 MHz or more. This configuration can improve the accuracy of current measurement.

[0221] In the evaluation system 1, the reaction vessel 2 has a temperature controller 23 that controls the temperature inside the reaction vessel 2 within a range from room temperature to 200° C. This configuration can improve the degree of freedom in setting the conditions for the evaluation test.

[0222] 15 is an example, and is not intended to be limiting. The order of setting the pressure and temperature (S83) and setting the pulse energy (S84) may be reversed, or these steps may be performed simultaneously.

[0223] [3. Aspects] As is clear from the above-described embodiment and modifications, the present disclosure includes the following aspects.

[0224] [Aspect 1] An evaluation system comprising: a reaction vessel in which a first electrode and a second electrode are disposed and which contains a working medium; a capacitor connected to each of the first electrode and the second electrode at both ends and to which a predetermined DC voltage greater than 2 kV is applied; and a semiconductor switch connected between the capacitor and the first electrode for applying pulse energy to the first electrode and the second electrode discharge circuit based on the voltage across the capacitor.

[0225] [Aspect 2] The evaluation system of aspect 1, wherein the distance between the first electrode and the second electrode is 30 μm or more.

[0226] [Aspect 3] The evaluation system of Aspect 1 or 2, wherein the first electrode and the second electrode are rod-shaped, and the central axes of the first electrode and the second electrode do not coincide with each other.

[0227] [Aspect 4] The evaluation system of Aspect 3, wherein the central axes of the first electrode and the second electrode are parallel to each other, the first electrode and the second electrode face each other in a direction perpendicular to the central axes of the first electrode and the second electrode, and the length of the portions of the first electrode and the second electrode facing each other in the direction perpendicular to the central axes of the first electrode and the second electrode is 0.5 mm or more.

[0228] [Aspect 5] A method for evaluating a reaction of a working medium, which is executed in an evaluation system, the evaluation system comprising: a reaction vessel having a first electrode and a second electrode disposed therein and containing the working medium; a capacitor having both ends connected to each of the first electrode and the second electrode and to which a predetermined DC voltage is applied; a semiconductor switch connected between the capacitor and the first electrode and for applying pulse energy to the first electrode and the second electrode based on a voltage across the capacitor; and a computing device; the evaluation method is executed by the computing device, and includes determining a value of discharge energy as the reaction of the working medium progresses, based on changes over time in voltage and current between the first electrode and the second electrode accompanying discharge generated by applying the pulse energy to the first electrode and the second electrode, or on the capacitance and charging voltage of the capacitor.

[0229] [Aspect 6] The evaluation method of Aspect 5, wherein determining the value of discharge energy when the reaction of the working medium has progressed includes: determining, from the discharge period when the discharge is occurring, an AC discharge period when an AC discharge is occurring and a DC discharge period when a DC discharge is occurring, based on the changes in the voltage and current over time; calculating AC discharge energy in the AC discharge period based on the relationship between the voltage and the current obtained from the changes in the voltage and current over time; calculating DC discharge energy in the DC discharge period based on the change in power over time obtained from the changes in the voltage and current over time; and determining the value of discharge energy when the reaction of the working medium has progressed from the AC discharge energy and the DC discharge energy.

[0230] [Aspect 7] The evaluation method of Aspect 5 or 6, further comprising calculating a degree of progress of the reaction of the working fluid based on a change in at least one of the temperature in the reaction vessel, the pressure in the reaction vessel, the composition of the working fluid, or the amount of a reaction product of the working fluid, during a predetermined period from the occurrence of the discharge.

[0231] [Aspect 8] The evaluation method of Aspect 7, further comprising: comparing the pressure inside the reaction vessel during the predetermined period with the withstand pressures of a plurality of components including a compressor of the refrigeration cycle device to determine the possibility of damage to the refrigeration cycle device; and, if it is assessed that there is a possibility of damage to the refrigeration cycle device, extracting a working medium that has a different composition from the evaluated working medium and a higher critical energy than the evaluated working medium.

[0232] [Aspect 9] The evaluation method according to any one of Aspects 5 to 7, further comprising: determining an electric power input to the compressor based on a configuration of a power source of the compressor of a refrigeration cycle device that uses the working medium; and determining a pulse width of an applied pulse that determines the pulse energy based on the electric power and the configuration of the power source.

[0233] [Aspect 10] The evaluation method of Aspect 8, further comprising: identifying an internal region in the compressor where a potential difference occurs across a gap equal to or smaller than a quenching distance of the working medium; and determining the withstand pressure in the internal region as the withstand pressure of the compressor.

[0234] [Aspect 11] The evaluation method of Aspect 8, wherein the compressor includes an electric motor, and further comprising determining the withstand pressure of the compressor to be a withstand pressure in a region around a coil of the electric motor.

[0235] [Aspect 12] The evaluation method of Aspect 7, wherein the reaction of the working medium is determined to have progressed if the temperature or pressure in the reaction vessel becomes 1.5 times or more of the temperature or pressure before the discharge occurs within the predetermined period.

[0236] [Aspect 13] The evaluation method of Aspect 7, wherein the reaction of the working medium is determined to have progressed if the composition of the working medium changes by more than 10% from the composition of the working medium before the discharge occurs within the predetermined period.

[0237] [Aspect 14] The evaluation method of Aspect 7, wherein the reaction of the working fluid is determined to have progressed when the amount of substance of the reaction product within the predetermined period of time becomes 10% or more of the total amount of substance of the working fluid before the occurrence of the discharge.

[0238] [Aspect 15] A program for causing the arithmetic device to execute the evaluation method according to any one of aspects 5 to 14.

[0239] Aspects 2 to 4 and 6 to 14 are optional elements and are not essential.

[0240] [Aspect 21] An evaluation method comprising: calculating a degree of progress of a reaction of the working medium based on a change in at least one of a temperature in the reaction vessel, a pressure in the reaction vessel, a composition of the working medium, or an amount of a reaction product of the working medium, during a predetermined period from the occurrence of a discharge caused by supplying pulse energy from a capacitor to a first electrode and a second electrode disposed in the reaction vessel containing the working medium; and determining a value of discharge energy when the reaction of the working medium has progressed based on a change over time in a voltage and a current between the first electrode and the second electrode caused by the discharge, or a capacitance and a charging voltage of the capacitor.

[0241] [Aspect 22] The evaluation method of Aspect 21, further comprising: comparing the pressure in the reaction vessel during the predetermined period with the withstand pressures of a plurality of components including a compressor of a refrigeration cycle device that uses the working fluid, to evaluate the possibility of damage to the refrigeration cycle device.

[0242] [Aspect 23] The evaluation method of Aspect 21 or 22, further comprising: determining electric power input to the compressor based on a configuration of a power source of a compressor of a refrigeration cycle device that uses the working medium; and determining a pulse width of an applied pulse that determines the pulse energy based on the electric power and the configuration of the power source.

[0243] [Aspect 24] The evaluation method of Aspect 23, wherein the power source is either an inverter type or a constant speed type.

[0244] [Aspect 25] The evaluation method of Aspect 22, further comprising: identifying an internal region in the compressor where a potential difference occurs across a gap equal to or smaller than a quenching distance of the working medium; and determining the withstand pressure in the internal region as the withstand pressure of the compressor.

[0245] [Aspect 26] The evaluation method of Aspect 22, wherein the compressor includes an electric motor, and further comprising determining the withstand pressure of the compressor to be a withstand pressure in a region around a coil of the electric motor.

[0246] [Aspect 27] The evaluation method of any one of Aspects 21 to 26, wherein the reaction of the working medium is determined to have progressed if the temperature in the reaction vessel or the pressure in the reaction vessel becomes 1.5 times or more of the temperature before the discharge occurred within the predetermined period.

[0247] [Aspect 28] The evaluation method of any one of Aspects 21 to 27, wherein the reaction of the working medium is determined to have progressed if the composition of the working medium changes by more than 10% from the composition of the working medium before the discharge occurred within the predetermined period.

[0248] [Aspect 29] The evaluation method of any one of Aspects 21 to 28, wherein the reaction of the working fluid is determined to have progressed when the amount of substance of the reaction product within the predetermined period of time becomes 10% or more of the total amount of substance of the working fluid before the occurrence of the discharge.

[0249] [Aspect 30] A program for causing a computer system to execute the evaluation method according to any one of aspects 21 to 29.

[0250] [Aspect 31] An evaluation method comprising: determining a discharge period during which a discharge is occurring based on a time change in a voltage and a current between a first electrode and a second electrode disposed in a reaction vessel containing a working medium, the discharge being caused by the discharge; determining an AC discharge period during which an AC discharge is occurring and a DC discharge period during which a DC discharge is occurring from the discharge period based on the time change in the voltage and current; calculating AC discharge energy during the AC discharge period based on a relationship between the voltage and the current obtained from the time change in the voltage and current; calculating DC discharge energy during the DC discharge period based on the time change in power obtained from the time change in the voltage and current; and determining a value of discharge energy when a reaction of the working medium has progressed from the AC discharge energy and the DC discharge energy.

[0251] [Aspect 32] A program for causing a computer system to execute the evaluation method of aspect 31.

[0252] Aspects 22 to 29 are optional elements and are not required.

[0253] [Aspect 41] An electric discharge generating device comprising: a discharge circuit having a first electrode and a second electrode; and a drive circuit that generates an electric discharge between the first electrode and the second electrode, wherein the drive circuit has: a capacitor connected to the first electrode and the second electrode at both ends thereof, respectively, and to which a predetermined DC voltage is applied; and a semiconductor switch connected between the capacitor and the first electrode, for applying pulse energy to the discharge circuit based on the voltage across the capacitor.

[0254] [Aspect 42] The discharge generator of Aspect 41, wherein the drive circuit further includes a current limiter connected between the capacitor or the first electrode and the semiconductor switch, and limiting at least one of a pulse width and a maximum power value of an applied pulse that determines the pulse energy.

[0255] [Aspect 43] The discharge generator according to Aspect 41 or 42, wherein the drive circuit has a pulse power supply for applying a pulse signal to the semiconductor switch to turn on the semiconductor switch.

[0256] [Aspect 44] The discharge generator according to any one of Aspects 41 to 43, wherein the first electrode and the second electrode are rod-shaped, and the central axes of the first electrode and the second electrode do not coincide with each other.

[0257] [Aspect 45] The discharge generator of Aspect 44, wherein central axes of the first electrode and the second electrode are parallel to each other, the first electrode and the second electrode face each other in a direction perpendicular to the central axes of the first electrode and the second electrode, and a length of the portions of the first electrode and the second electrode facing each other in the direction perpendicular to the central axes of the first electrode and the second electrode is 0.5 mm or more.

[0258] [Aspect 46] The discharge generator according to any one of Aspects 41 to 45, wherein the distance between the first electrode and the second electrode is 30 μm or more.

[0259] [Aspect 47] The discharge generator according to any one of Aspects 41 to 46, wherein the capacitance of the capacitor is 20 pF or more and 10 mF or less.

[0260] [Aspect 48] The discharge generator according to Aspect 42, wherein the current limiter includes at least one of a resistor of 20Ω or less and a reactor of 20H or less.

[0261] [Aspect 49] The conductivity of the material of the first electrode and the second electrode is 1×10 ７ 49. The discharge generator according to any one of aspects 41 to 48, wherein the electrical conductivity is 1.5 S / m or more.

[0262] [Aspect 50] The discharge generator according to any one of Aspects 41 to 49, wherein the impedance of the electric path between the capacitor and the discharge circuit is 0.5 Ω or less.

[0263] [Aspect 51] The discharge generator according to any one of Aspects 41 to 50, further comprising a DC power supply that applies the predetermined DC voltage to the capacitor, wherein the predetermined DC voltage is greater than 2 kV.

[0264] [Aspect 52] An evaluation system comprising: the discharge generator according to any one of Aspects 41 to 51; a reaction vessel in which the first electrode and the second electrode are placed; a reaction measurement device that measures the reaction in the reaction vessel; and a discharge measurement device that measures the discharge of the discharge circuit.

[0265] [Aspect 53] The evaluation system of aspect 52, wherein the reaction vessel has a design pressure resistance of 30 MPa or more.

[0266] [Aspect 54] The evaluation system of Aspect 52 or 53, wherein the reaction vessel has a control valve that opens when the pressure inside the reaction vessel reaches or exceeds two-thirds of the design pressure.

[0267] [Aspect 55] The evaluation system according to any one of Aspects 52 to 54, wherein the reaction measurement device includes at least one of a pressure sensor that measures the pressure inside the reaction vessel, and a temperature sensor that measures the temperature inside the reaction vessel.

[0268] 56. The evaluation system of claim 55, wherein the pressure sensor includes a high-speed pressure gauge.

[0269] [Aspect 57] The evaluation system of Aspect 55 or 56, wherein the temperature sensor includes a thermocouple.

[0270] [Aspect 58] The evaluation system of any one of Aspects 52 to 57, wherein the discharge measurement device includes at least one of a voltage probe that measures a change over time in a voltage between the first electrode and the second electrode of the discharge circuit, and a current probe that measures a change over time in a current flowing between the first electrode and the second electrode of the discharge circuit.

[0271] [Aspect 59] The evaluation system of Aspect 58, wherein the voltage probe includes a differential voltmeter having a bandwidth of 20 MHz or more.

[0272] [Aspect 60] The evaluation system of Aspect 58 or 59, wherein the current probe includes a non-contact ammeter having a bandwidth of 20 MHz or more.

[0273] [Aspect 61] The evaluation system according to any one of Aspects 52 to 60, wherein the reaction vessel has a temperature controller that controls the temperature inside the reaction vessel within a range from room temperature to 200°C.

[0274] Aspects 42 to 51 and Aspects 53 to 61 are optional elements and are not essential.

[0275] The present disclosure is applicable to an evaluation method and a program, specifically to an evaluation method for a working fluid for a refrigeration cycle device and a program for causing a computer system to execute the evaluation method.

[0276] The present disclosure is applicable to a discharge generator and an evaluation system. Specifically, the present disclosure is applicable to a discharge generator that generates a discharge for causing a reaction, and an evaluation system that evaluates the reaction using the discharge generator.

[0277] REFRIGERATION SYSTEM 1 Evaluation system 2 Reaction vessel 31 First electrode 32 Second electrode 41 Capacitor 42 Semiconductor switch 100 Refrigeration cycle device 1031 Drive circuit (power source) 104 Compressor 200 Working medium

Claims

1. An evaluation system comprising: a reaction vessel having a first electrode and a second electrode disposed therein and containing a working medium; a capacitor having both ends connected to each of the first electrode and the second electrode and to which a predetermined DC voltage greater than 2 kV is applied; and a semiconductor switch connected between the capacitor and the first electrode for applying pulse energy to the first electrode and the second electrode based on the voltage across the capacitor.

2. The evaluation system according to claim 1, wherein the distance between the first electrode and the second electrode is 30 μm or more.

3. The evaluation system according to claim 1, wherein the first electrode and the second electrode are rod-shaped, and the central axes of the first electrode and the second electrode do not coincide with each other.

4. The evaluation system of claim 3, wherein the central axes of the first electrode and the second electrode are parallel to each other, the first electrode and the second electrode face each other in a direction perpendicular to the central axes of the first electrode and the second electrode, and the length of the portions of the first electrode and the second electrode facing each other in a direction perpendicular to the central axes of the first electrode and the second electrode is 0.5 mm or more.

5. A method for evaluating a reaction of a working medium executed in an evaluation system, the evaluation system comprising: a reaction vessel in which a first electrode and a second electrode are disposed and which contains the working medium; a capacitor connected at both ends to each of the first electrode and the second electrode and to which a predetermined DC voltage is applied; a semiconductor switch connected between the capacitor and the first electrode and for applying pulse energy to the first electrode and the second electrode based on the voltage across the capacitor; and a computing device, the evaluation method being executed by the computing device and including determining a value of discharge energy as the reaction of the working medium progresses based on the changes over time in voltage and current between the first electrode and the second electrode accompanying discharge generated by applying the pulse energy to the first electrode and the second electrode, or the capacitance and charging voltage of the capacitor.

6. The evaluation method of claim 5, wherein determining the value of discharge energy when the reaction of the working medium has progressed includes: determining, from the discharge period in which the discharge is occurring, an AC discharge period in which an AC discharge is occurring and a DC discharge period in which a DC discharge is occurring, based on the changes in the voltage and current over time; calculating AC discharge energy in the AC discharge period based on the relationship between the voltage and the current obtained from the changes in the voltage and current over time; calculating DC discharge energy in the DC discharge period based on the change in power over time obtained from the changes in the voltage and current over time; and determining the value of discharge energy when the reaction of the working medium has progressed from the AC discharge energy and the DC discharge energy.

7. The evaluation method according to claim 5, further comprising calculating the degree of progress of the reaction of the working medium based on a change in at least one of the temperature in the reaction vessel, the pressure in the reaction vessel, the composition of the working medium, or the amount of a reaction product of the working medium, during a predetermined period from the occurrence of the discharge.

8. The evaluation method of claim 7, further comprising: comparing the pressure inside the reaction vessel during the specified period with the withstand pressure of a plurality of components including a compressor of the refrigeration cycle device to evaluate the possibility of damage to the refrigeration cycle device; and, if it is evaluated that there is a possibility of damage to the refrigeration cycle device, extracting a working medium that has a different composition from the evaluated working medium and a higher critical energy than the evaluated working medium.

9. The evaluation method of claim 5, further comprising: determining the power input to the compressor based on the configuration of a power source of the compressor of a refrigeration cycle device that uses the working medium; and determining the pulse width of an applied pulse that determines the pulse energy based on the power and the configuration of the power source.

10. The evaluation method according to claim 8, further comprising: identifying an internal region in the compressor where a potential difference occurs across a gap equal to or smaller than the quenching distance of the working medium; and determining the withstand pressure in the internal region as the withstand pressure of the compressor.

11. The evaluation method according to claim 8, wherein the compressor includes an electric motor, and further comprising determining the withstand pressure of the compressor to be the withstand pressure of a region around a coil of the electric motor.

12. The evaluation method of claim 7, wherein the reaction of the working medium is determined to have progressed if the temperature or pressure inside the reaction vessel becomes 1.5 times or more higher than before the discharge occurred within the specified period.

13. The evaluation method according to claim 7, wherein the reaction of the working medium is determined to have progressed if the composition of the working medium changes by more than 10% from the composition of the working medium before the discharge occurred within the specified period.

14. The evaluation method of claim 7, wherein the reaction of the working medium is determined to have progressed if the amount of substance of the reaction product within the specified period of time becomes 10% or more of the total amount of substance of the working medium before the discharge occurred.

15. A program for causing the computing device to execute the evaluation method of claim 5.

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