WO2015140871A1

WO2015140871A1 - Refrigeration cycle device

Info

Publication number: WO2015140871A1
Application number: PCT/JP2014/057029
Authority: WO
Inventors: 拓也伊藤; 靖大越
Original assignee: 三菱電機株式会社; 旭硝子株式会社
Priority date: 2014-03-17
Filing date: 2014-03-17
Publication date: 2015-09-24
Also published as: JPWO2015140871A1; JP6289611B2

Abstract

A refrigeration cycle device (100A) wherein, when a compressor (1) is started, a control device (20) restricts the rotational frequency of the compressor (1) on the basis of a disproportionation reaction pressure value obtained from the discharge gas temperature of a refrigerant discharged from the compressor (1) and the condenser outlet temperature of the refrigerant discharged from a first heat exchanger (3) functioning as a condenser.

Description

Refrigeration cycle equipment

The present invention relates to a refrigeration cycle apparatus that enables safe operation even when a working refrigerant whose main component is a refrigerant having a property of causing a disproportionation reaction is used.

In recent years, from the viewpoint of global warming, the development of low GWP refrigerant is progressing. As a candidate for a low GWP refrigerant, HFO-1123 (CF ₂ ═CHF; 1, 1, ₂ trifluoroethene (ethylene)), which is a kind of HFO refrigerant, is known. Assuming that a refrigerant containing HFO-1123 is used, “a heat cycle system in which the refrigerant contains HFO-1123 in a refrigerant circuit in which a compressor for circulating the refrigerant, a condenser, an expansion valve, and an evaporator are sequentially connected by piping” Has been proposed (see, for example, Patent Document 1).

WO2012 / 157774 (pages 12-13, FIG. 1)

However, HFO-1123 has a property of causing a reaction called a disproportionation reaction (autolysis reaction). The disproportionation reaction generates heat and HF (hydrogen fluoride) as shown in the following reaction formula.
CF ₂ = CHF → 1 / 2CF ₄ + 3 / 2C + HF + 44.7 kcal / mol

In a heat cycle system using a refrigerant containing HFO-1123, a chemical reaction accompanied by heat generation proceeds when energy is input in a high temperature and high pressure state due to a disproportionation reaction, and a rapid pressure rise accompanying a sudden temperature rise Occurred, and there was a problem of danger of explosion. HFO-1123 undergoes a disproportionation reaction when abrupt energy is applied, but whether it propagates to the surroundings after generation depends on the gas pressure.

Further, when using HFO-1123, it is necessary to mix a refrigerant such as HFO1234yf in order to expand the region where the disproportionation reaction does not occur. However, when a refrigerant having a low density is mixed with HFO-1123, the size of the refrigeration cycle apparatus per unit capacity increases, resulting in an increase in product cost.

Moreover, in the conventional refrigeration cycle apparatus, the high pressure detection is aimed at protecting the compressor and protecting the refrigerant circuit from damage due to a rise in pressure in the refrigerant circuit. A pressure sensor is provided. However, when using HFO-1123, in order to suppress the disproportionation reaction, it is also necessary to suppress an increase in pressure at the place where the refrigerant liquid at the outlet of the condenser stays.

The present invention has been made to solve the above-described problems. Even when HFO-1123 is used, the HFO-1123 is unevenly distributed based on the pressure at the discharge pipe of the compressor and the outlet of the condenser. It aims at providing the refrigerating-cycle apparatus which can suppress the increase in the cost of a product and can suppress the increase in the weight of a product by controlling within the pressure range which does not react.

The refrigeration cycle apparatus according to the present invention has a refrigerant circuit in which at least a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected by piping, and the refrigerant circuit is filled with a refrigerant containing HFO-1123. When the compressor is started up, the refrigerant discharge rate determined by the refrigerant discharge gas temperature discharged from the compressor and the refrigerant outlet temperature of the refrigerant flowing out of the condenser is determined. The rotation speed of the compressor is suppressed based on the leveling reaction pressure value.

According to the refrigeration cycle apparatus according to the present invention, since the rotation speed of the compressor is suppressed based on the disproportionation reaction pressure value, the pressure is suppressed within a range in which the disproportionation reaction of HFO-1123 does not propagate. Is possible.

It is a schematic block diagram which shows an example of the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the flow of the disproportionation reaction suppression control process which the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention performs. It is a graph which shows the pressure value which disproportionation reaction of HFO-1123 generate | occur | produces. It is a schematic block diagram which shows an example of the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention. It is a flowchart which shows the flow of the disproportionation reaction suppression control process which the refrigeration cycle apparatus which concerns on Embodiment 2 of this invention performs. It is a graph which shows the starting pattern of the compressor mounted in the program of the control apparatus of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention. 5 is a graph showing disproportionation reaction regions in the case of using HFO-1123 alone and in the case of a mixed refrigerant of HFO-1123 and HFO1234yf. It is a flowchart which shows the flow of the disproportionation reaction suppression control process which the refrigeration cycle apparatus which concerns on Embodiment 3 of this invention performs.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one. Further, in the following drawings including FIG. 1, the same reference numerals denote the same or equivalent parts, and this is common throughout the entire specification. Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram showing an example of a refrigerant circuit configuration of a refrigeration cycle apparatus (hereinafter referred to as refrigeration cycle apparatus 100A) according to Embodiment 1 of the present invention. FIG. 2 is a flowchart showing the flow of the disproportionation reaction suppression control process executed by the refrigeration cycle apparatus 100A. FIG. 3 is a graph showing the pressure value at which the disproportionation reaction of HFO-1123 occurs. The refrigeration cycle apparatus 100A will be described with reference to FIGS.

In the refrigeration cycle apparatus 100A, a working refrigerant whose main component is a refrigerant having a property of causing a disproportionation reaction is filled in a refrigerant circuit. As a working refrigerant mainly composed of a refrigerant having a property of causing a disproportionation reaction, a single refrigerant of HFO-1123, a mixed refrigerant of HFO-1123 and R32, or a mixed refrigerant of HFO-1123 and HFO-1234yf Can be considered. When a mixed refrigerant of HFO-1123 and R32 or a mixed refrigerant of HFO-1123 and HFO-1234yf is used as a working refrigerant, the content of R32 and HFO-1234yf is in the range of 20 to 50% by mass. The content of HFO-1123 should not exceed mass%.

The refrigeration cycle apparatus 100A includes a compressor 1 for compressing refrigerant, a four-way valve 2 as refrigerant circuit switching means for switching refrigerant flow paths, a first heat exchanger 3 for exchanging heat with refrigerant and a heat medium such as air or water, It has an expansion valve 4 (an example of a pressure reducing mechanism) that controls the flow rate of the refrigerant, and a second heat exchanger 5 that exchanges heat between the refrigerant and a heat medium such as air or water. In the refrigeration cycle apparatus 100A, the compressor 1, the four-way valve 2, the first heat exchanger 3, the expansion valve 4, and the second heat exchanger 5 are connected by a refrigerant pipe 30 to constitute a refrigerant circuit.

As the compressor 1 that compresses the refrigerant, an inverter compressor of a type in which the number of revolutions is controlled by an inverter circuit and the capacity is controlled is used, and the number of revolutions can be controlled. Examples of the inverter compressor include a rotary compressor, a scroll compressor, a screw compressor, and a reciprocating compressor.

The four-way valve 2 switches the refrigerant flow path according to a cooling / heating supply mode (for example, cooling operation mode) and a heating / heating supply mode (for example, heating operation mode).
The four-way valve 2 will be described as an example of the refrigerant circuit switching means. However, the refrigerant circuit switching means may be configured by combining two refrigerant valves, for example, two two-way valves or three-way valves. Good. Moreover, although the case where the four-way valve 2 is provided is shown as an example, when the refrigerant circuit configuration in which the refrigerant flow path is not switched is adopted as the refrigeration cycle apparatus 100A, it is not necessary to provide the refrigerant circuit switching means.

The first heat exchanger 3 functions as a condenser or an evaporator, and is configured in a format corresponding to a heat medium to exchange heat. For example, in the case of exchanging heat with air, the first heat exchanger 3 can be configured by a cross fin type fin-and-tube heat exchanger. In addition, when exchanging heat with water, brine, or the like, the first heat exchanger 3 includes a microchannel heat exchanger, a shell and tube heat exchanger, a heat pipe heat exchanger, and a double pipe heat exchanger. It can be constituted by a plate heat exchanger or the like.

The expansion valve 4 can adjust the refrigerant flow rate. As an example of the pressure reducing mechanism, the expansion valve 4 having a structure with a variable throttle opening is described as an example. However, the present invention is not limited to this, and a mechanical expansion valve that employs a diaphragm as a pressure receiving portion. Alternatively, the pressure reducing mechanism may be constituted by a capillary tube.

The second heat exchanger 5 functions as an evaporator or a condenser, and is configured in a format corresponding to the heat medium to be heat exchanged. For example, in the case of exchanging heat with air, the second heat exchanger 5 can be configured by a cross fin type fin-and-tube heat exchanger. When heat is exchanged with water or brine, the second heat exchanger 5 includes a microchannel heat exchanger, a shell and tube heat exchanger, a heat pipe heat exchanger, and a double pipe heat exchange. And a plate heat exchanger.

Further, the refrigeration cycle apparatus 100A has a discharge pressure sensor 10, a discharge temperature sensor 11, a condenser outlet pressure sensor 12, a condenser outlet temperature sensor 13, and a control device 20.

The discharge pressure sensor 10 is installed on the discharge side of the compressor 1 and measures the discharge gas pressure of the refrigerant discharged from the compressor 1.
The discharge temperature sensor 11 is installed on the discharge side of the compressor 1 and measures the discharge gas temperature of the refrigerant discharged from the compressor 1.
The condenser outlet pressure sensor 12 is installed between the first heat exchanger 3 and the expansion valve 4, and the refrigerant that has flowed out of the first heat exchanger 3 when the first heat exchanger 3 functions as a condenser. Measure the outlet pressure of the condenser.
The condenser outlet temperature sensor 13 is installed between the first heat exchanger 3 and the expansion valve 4, and the refrigerant that has flowed out of the first heat exchanger 3 when the first heat exchanger 3 functions as a condenser. Measure the outlet temperature of the condenser.

The control device 20 performs overall control of the entire refrigeration cycle apparatus 100A. Based on the measured values from the detectors (discharge pressure sensor 10, discharge temperature sensor 11, condenser outlet pressure sensor 12, condenser outlet temperature sensor 13), the control device 20 controls each actuator (compressor 1, four-way valve 2). , Drive parts such as the expansion valve 4 are controlled. The control device 20 can be configured by hardware such as a circuit device that realizes the function, or can be configured by an arithmetic device such as a microcomputer or a CPU and software executed thereon.

In FIG. 1, in the cooling / heating mode for supplying cooling from the second heat exchanger 5 (for example, cooling operation), the four-way valve 2 becomes a solid flow path, and the heating / heating supply mode for supplying warm from the second heat exchanger 5. In (for example, heating operation), the four-way valve 2 is switched to a dotted flow path. Therefore, in the cold supply mode, the compressor 1, the four-way valve 2, the first heat exchanger 3, the expansion valve 4, the second heat exchanger 5, and the compressor 1 are connected in an annular shape in this order. In the warm heat supply mode, the compressor 1, the four-way valve 2, the second heat exchanger 5, the expansion valve 4, the first heat exchanger 3, and the compressor 1 are annularly connected in this order. Therefore, in the cold heat supply mode, the first heat exchanger 3 functions as a condenser, and the second heat exchanger 5 functions as an evaporator. In the warm heat supply mode, the first heat exchanger 3 functions as an evaporator, and the second heat exchanger 5 functions as a condenser.

Next, the working refrigerant used for the refrigeration cycle apparatus 100A will be described.
As a working refrigerant used in the

refrigeration cycle apparatus

100A, 1, 1, 2 trifluoroethylene (HFO-1123) having a low GWP and a high operating pressure is used as a main component. As shown in the following reaction formula, HFO-1123 undergoes a disproportionation reaction in which a substance (HF) having heat and toxicity is generated.
CF ₂ = CHF → 1 / 2CF ₄ + 3 / 2C + HF + 44.7 kcal / mol

3 that the pressure value at which the disproportionation reaction of HFO-1123 occurs tends to decrease as the temperature increases. It is also known that when R32 or HFO-1234yf is mixed, the pressure value at which the disproportionation reaction of HFO-1123 occurs tends to decrease.

Therefore, in the refrigeration cycle apparatus 100A, when the compressor 1 is started, a judgment value for the pressure value for each temperature at which the disproportionation reaction of HFO-1123 occurs is mounted in advance in the program of the control apparatus 20, and the discharge gas temperature The value of the disproportionation reaction pressure obtained from the condenser outlet temperature (hereinafter referred to as the disproportionation reaction pressure value) is calculated. In the refrigeration cycle apparatus 100A, when the compressor 1 is started, disproportionation reaction suppression control is performed to suppress an increase in the rotational speed of the compressor 1 so as not to exceed the disproportionation reaction pressure value.

For example, when the detected pressure reaches the pressure determination value, the increase in the frequency of the compressor 1 is stopped, and when there is no decrease in the pressure after a certain time, control is performed to decrease the rotation speed of the compressor 1. This control is performed at both the discharge part of the compressor 1 and the outlet part of the first heat exchanger 3 that functions as a condenser. Further, the controller 20 incorporates in advance a rotation speed increase pattern at the time of starting the compressor 1 as shown in FIG. 6 so that the discharge gas pressure or the condenser outlet pressure before the compressor 1 is started. Thus, the startup pattern of the compressor 1 may be determined. Note that FIG. 6 will be described in Embodiment 2.

Hereinafter, a specific control flow of the disproportionation reaction suppression control of the refrigeration cycle apparatus 100A will be described with reference to FIG. In the control flow of the disproportionation reaction suppression control described here, it is assumed that the first heat exchanger 3 functions as a condenser.

When the refrigeration cycle apparatus 100A starts operation, the control device 20 detects the discharge gas pressure P1 and the discharge gas temperature T1 from the pressure value measured by the discharge pressure sensor 10 and the temperature value measured by the discharge temperature sensor 11. (Step S101).
Subsequently, the control device 20 detects the condenser outlet pressure P2 and the condenser outlet temperature T2 from the pressure value measured by the condenser outlet pressure sensor 12 and the temperature value measured by the condenser outlet temperature sensor 13 ( Step S102).

The control device 20 determines whether or not the discharge gas pressure P1 is larger than the lower limit value of the disproportionation reaction pressure value obtained from the discharge gas temperature T1 and the condenser outlet temperature T2 (step S103).
When it is determined that the discharge gas pressure P1 is equal to or lower than the lower limit value of the disproportionation reaction pressure value (step S103; N), the control device 20 determines whether the condenser outlet pressure P2 is larger than the lower limit value of the disproportionation reaction pressure value. Is determined (step S104).
When it is determined that the condenser outlet pressure P2 is equal to or lower than the lower limit value of the disproportionation reaction pressure value (step S104; N), the control device 20 causes the HFO-1123 to disproportionate even when the compressor 1 is started. Therefore, the compressor 1 is controlled normally, and the process returns to step S101.

When it is determined that the discharge gas pressure P1 is larger than the lower limit value of the disproportionation reaction pressure value (step S103; Y), or when it is determined that the condenser outlet pressure P2 is larger than the lower limit value of the disproportionation reaction pressure value ( In step S104; Y), the control device 20 sets the increase amount of the rotation speed of the compressor 1 to 0 (step S105). In these cases, the control device 20 determines that there is a possibility that the HFO-1123 becomes equal to or higher than the disproportionation reaction pressure value at the time of starting the compressor 1, and controls to suppress an increase in the rotational speed of the compressor 1. To do.

Subsequently, the control device 20 determines whether or not a predetermined pressure decrease standby time has elapsed (step S106). If it is determined that the pressure drop standby time has not elapsed (step S106; N), the control device 20 returns to step S105 and keeps the increase amount of the rotation speed of the compressor 1 at zero. The pressure drop standby time may be determined in advance according to the discharge gas pressure P1 and the condenser outlet pressure P2, and is not fixed uniformly.

If it is determined that the pressure drop standby time has elapsed (step S106; Y), the controller 20 determines that both the discharge gas pressure P1 and the condenser outlet pressure P2 are lower than the lower limit value of the disproportionation reaction pressure value. It is determined whether it is larger (step S107).
Then, when it is determined that the discharge gas pressure P1 and the condenser outlet pressure P2 are larger than the lower limit value of the disproportionation reaction pressure value (step S107; Y), the control device 20 is still in the start-up of the compressor 1. It is determined that there is a possibility that HFO-1123 becomes equal to or higher than the disproportionation reaction pressure value, and control is performed to reduce the rotational speed of the compressor 1 (step S108).

On the other hand, when it is determined that the discharge gas pressure P1 and the condenser outlet pressure P2 are equal to or less than the disproportionation reaction pressure value (step S107; N), the control device 20 causes the HFO-1123 to disproportionate even when the compressor 1 is started. It is determined that the conversion reaction will not occur, the compressor 1 is normally controlled, and the process returns to step S101.

As described above, in the refrigeration cycle apparatus 100A, when the compressor 1 is started, the disproportionation reaction is suppressed so that the increase in the rotation speed of the compressor 1 is suppressed so as not to exceed the disproportionation reaction pressure value of HFO-1123. Take control. Therefore, according to the refrigeration cycle apparatus 100A, even when HFO-1123 is used, the refrigerant circuit is within a pressure range in which HFO-1123 does not disproportionately react based on the discharge gas pressure of the compressor 1 and the condenser outlet pressure. It becomes possible to control the pressure. Further, according to the refrigeration cycle apparatus 100A, it is possible to accurately suppress the disproportionation reaction of HFO-1123 by detecting the condenser outlet pressure.

Furthermore, since the refrigeration cycle apparatus 100A can effectively utilize the pressure range in which the disproportionation reaction can be suppressed, even if a mixed refrigerant is used as the working refrigerant, the ratio of refrigerants other than HFO-1123 can be reduced. Therefore, according to the refrigeration cycle apparatus 100A, the mixing ratio of refrigerants other than HFO-1123 to be mixed can be minimized, an increase in product cost can be suppressed, and an increase in product weight (an increase in unit size). ) Can be suppressed.

Embodiment 2. FIG.
FIG. 4 is a schematic configuration diagram showing an example of a refrigerant circuit configuration of a refrigeration cycle apparatus (hereinafter referred to as refrigeration cycle apparatus 100B) according to Embodiment 2 of the present invention. FIG. 5 is a flowchart showing the flow of the disproportionation reaction suppression control process executed by the refrigeration cycle apparatus 100B. FIG. 6 is a graph showing a startup pattern of the compressor 1 installed in the program of the control device 20 of the refrigeration cycle apparatus 100B. The refrigeration cycle apparatus 100B will be described with reference to FIGS. In the second embodiment, differences from the first embodiment will be mainly described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

The refrigeration cycle apparatus 100B includes an outside air temperature sensor 14 and a water outlet temperature sensor 15 in addition to the configuration of the refrigeration cycle apparatus 100A according to the first embodiment.

The outside air temperature sensor 14 is installed in the vicinity of the first heat exchanger 3 and measures the temperature of the outside air.
The water outlet temperature sensor 15 is installed at the water-side outlet of the second heat exchanger 5 and measures the temperature of the water that has flowed out of the second heat exchanger 5.
That is, in the refrigeration cycle apparatus 100 </ b> B, the refrigerant and water (may be brine) are heat-exchanged by the second heat exchanger 5.

Also in the refrigeration cycle apparatus 100B, disproportionation reaction suppression control is executed in the same manner as the refrigeration cycle apparatus 100A according to the first embodiment. For example, when the first heat exchanger 3 of the refrigeration cycle apparatus 100B is air-cooled, the high pressure is assumed to be approximately the outside air temperature in the cooling operation. Therefore, in the refrigeration cycle apparatus 100B, the pressure after starting the compressor 1 is estimated from the outside air temperature before starting the compressor 1, and when the outside air temperature is high, the discharge gas pressure and the condenser outlet pressure are disproportionated. Disproportionation reaction suppression control is performed to reduce the amount of increase in the rotational speed when the compressor 1 is started so that the generated pressure does not occur.

Hereinafter, a specific control flow of the disproportionation reaction suppression control of the refrigeration cycle apparatus 100B will be described with reference to FIG. In the control flow of the disproportionation reaction suppression control described here, it is assumed that the first heat exchanger 3 functions as a condenser.

When the refrigeration cycle apparatus 100B starts operation, the control apparatus 20 determines whether or not the outside air temperature measured by the outside air temperature sensor 14 is larger than a predetermined determination value A (step S201).
When it is determined that the outside air temperature is higher than the determination value A (step S201; Y), the control device 20 starts the compressor 1 with the start pattern A (step S202). In this case, the control device 20 determines that there is a possibility that the HFO-1123 becomes equal to or higher than the disproportionation reaction pressure value when the compressor 1 is started, and performs control to suppress an increase in the rotational speed of the compressor 1. Do.

If it is determined that the outside air temperature is equal to or lower than the determination value A (step S201; N), the control device 20 determines whether or not the outside air temperature measured by the outside air temperature sensor 14 is larger than a predetermined determination value B. (Step S203).
When it is determined that the outside air temperature is higher than the determination value B (step S203; Y), the control device 20 starts the compressor 1 with the start pattern B (step S204). In this case, the control device 20 determines that the HFO-1123 may be equal to or higher than the disproportionation reaction pressure value when the compressor 1 is started, although it is smaller than that in the start pattern A. Control is performed to suppress an increase in the rotational speed. The determination value A is a temperature higher than the determination value B.

When it is determined that the outside air temperature is equal to or lower than the determination value B (step S203; N), the control device 20 starts the compressor 1 with the start pattern C (step S205). In this case, the control device 20 determines that the HFO-1123 does not cause a disproportionation reaction even when the compressor 1 is started up, increases the rotation speed of the compressor 1, and returns to step S201.

Further, in the refrigeration cycle apparatus 100B, during the heating operation, the startup pattern of the compressor 1 is determined based on the water outlet temperature before the startup of the compressor 1 (see FIG. 6). Specifically, in the refrigeration cycle apparatus 100B, the pressure after startup of the compressor 1 is estimated from the water outlet temperature before startup of the compressor 1, and when the water outlet temperature is high, the discharge gas pressure and the condenser outlet pressure Is controlled so as to reduce the amount of increase in the rotational speed at the start of the compressor 1 so that the pressure does not become the disproportionation reaction generation pressure.

For example, when the water outlet temperature is higher than the predetermined determination value A1 before the compressor 1 is started, the control device 20 determines the start pattern A from FIG. In this case, the control device 20 determines that there is a possibility that the HFO-1123 becomes equal to or higher than the disproportionation reaction pressure value when the compressor 1 is started, and performs control to suppress an increase in the rotational speed of the compressor 1. Do.

Further, the control device 20 determines the activation pattern B from FIG. 6 when the water outlet temperature is equal to or lower than the determination value A1 and greater than the predetermined determination value B1 before the compressor 1 is started. In this case, the control device 20 determines that the HFO-1123 may be equal to or higher than the disproportionation reaction pressure value when the compressor 1 is started, although it is smaller than that in the start pattern A. Control is performed to suppress an increase in the rotational speed. The determination value A1 is a temperature higher than the determination value B1.

Moreover, the control apparatus 20 determines the starting pattern C from FIG. 6, when water outlet temperature is below the determination value B1 before the starting of the compressor 1. FIG. In this case, the control device 20 determines that the HFO-1123 does not cause a disproportionation reaction even when the compressor 1 is started up, and increases the rotational speed of the compressor 1.

As described above, in the refrigeration cycle apparatus 100B, when the compressor 1 is started, the disproportionation reaction is suppressed so that the increase in the rotational speed of the compressor 1 is suppressed so as not to exceed the disproportionation reaction pressure value of HFO-1123. Take control. Therefore, according to the refrigeration cycle apparatus 100B, even when HFO-1123 is used, the pressure in the refrigerant circuit can be controlled within a pressure range in which HFO-1123 does not disproportionate based on the outside air temperature. . Further, according to the refrigeration cycle apparatus 100B, it is possible to accurately suppress the disproportionation reaction of HFO-1123 by detecting the water outlet temperature during the heating operation.

In the refrigeration cycle apparatus 100B, if the disproportionation reaction suppression control in the refrigeration cycle apparatus 100A according to Embodiment 1 is incorporated, the disproportionation reaction of HFO-1123 can be suppressed with higher accuracy. . If it does in this way, it will become possible to exhibit the effect which 100A of refrigerating cycle devices concerning Embodiment 1 show similarly.

<Modification of refrigeration cycle apparatus 100B>
The pressure at which the disproportionation reaction occurs is different between the case of using HF0-1123 alone and the case of a mixed refrigerant such as HFO-1234yf. Therefore, the outside air temperature that determines the startup pattern of the compressor 1 can be set by the control device 20, and the startup pattern can be changed between when the HFO-1123 is used alone and when the refrigerant is mixed with HFO-1234yf or the like. Like that.

FIG. 7 is a graph showing the disproportionation reaction region in the case of using HFO-1123 alone and in the case of a mixed refrigerant of HFO-1123 and HFO1234yf. From FIG. 7, it can be seen that the pressure at which the disproportionation reaction occurs is different between the case of using HF0-1123 alone and the case of the mixed refrigerant with HFO-1234yf or the like. Therefore, in the refrigeration cycle apparatus 100B, the start pattern of the compressor 1 is changed depending on whether the working refrigerant is HFO-1123 used alone or a mixed refrigerant of HFO-1123 and another refrigerant. Is possible. This content can also be applied to the refrigeration cycle apparatus 100A according to the first embodiment.

Embodiment 3 FIG.
FIG. 8 is a flowchart showing the flow of the disproportionation reaction suppression control process executed by the refrigeration cycle apparatus according to Embodiment 3 of the present invention (hereinafter referred to as refrigeration cycle apparatus 100C, although not shown). The refrigeration cycle apparatus 100C will be described based on FIG. In the third embodiment, differences from the first and second embodiments will be mainly described, and the same parts as those in the first and second embodiments will be denoted by the same reference numerals and the description thereof will be omitted. The refrigerant circuit configuration of the refrigeration cycle apparatus 100C is the same as that of the refrigeration cycle apparatus 100A according to Embodiment 1.

Even in the refrigeration cycle apparatus 100C, the disproportionation reaction suppression control is executed in the same manner as the refrigeration cycle apparatus 100A according to the first embodiment. Specifically, in the refrigeration cycle apparatus 100 </ b> C, when the temperature and pressure are reached after the start of the compressor 1, the compressor 1 is stopped once and the expansion valve 4 is opened. By doing so, in the refrigeration cycle apparatus 100C, the pressure of the refrigerant in the refrigerant circuit is reduced, and the discharge gas pressure and the condenser outlet pressure of the compressor 1 are reduced. Thereafter, the refrigeration cycle apparatus 100 </ b> C restarts the compressor 1.

Hereinafter, a specific control flow of the disproportionation reaction suppression control of the refrigeration cycle apparatus 100C will be described with reference to FIG. In the control flow of the disproportionation reaction suppression control described here, it is assumed that the first heat exchanger 3 functions as a condenser.

When the refrigeration cycle apparatus 100C starts operation, the control device 20 detects the discharge gas pressure P1 and the discharge gas temperature T1 from the pressure value measured by the discharge pressure sensor 10 and the temperature value measured by the discharge temperature sensor 11. (Step S301).
Subsequently, the control device 20 detects the condenser outlet pressure P2 and the condenser outlet temperature T2 from the pressure value measured by the condenser outlet pressure sensor 12 and the temperature value measured by the condenser outlet temperature sensor 13 ( Step S302).

The control device 20 determines whether or not the discharge gas pressure P1 is larger than the lower limit value of the disproportionation reaction pressure value obtained from the discharge gas temperature T1 and the condenser outlet temperature T2 (step S303).
When determining that the discharge gas pressure P1 is equal to or lower than the lower limit value of the disproportionation reaction pressure value (step S303; N), the control device 20 determines whether the condenser outlet pressure P2 is larger than the lower limit value of the disproportionation reaction pressure value. Is determined (step S304).
When it is determined that the condenser outlet pressure P2 is equal to or lower than the lower limit value of the disproportionation reaction pressure value (step S304; N), the control device 20 causes the HFO-1123 to disproportionate even after the compressor 1 is started. Therefore, the compressor 1 is controlled normally, and the process returns to step S301.

When it is determined that the discharge gas pressure P1 is larger than the lower limit value of the disproportionation reaction pressure value (step S303; Y), or when it is determined that the condenser outlet pressure P2 is larger than the lower limit value of the disproportionation reaction pressure value ( In step S304; Y), the control device 20 stops the compressor 1 and opens the expansion valve 4 (step S305). In these cases, the control device 20 determines that there is a possibility that the HFO-1123 becomes equal to or higher than the disproportionation reaction pressure value after starting the compressor 1, stops the compressor 1, and opens the expansion valve 4. Control to do.

Subsequently, the control device 20 determines whether or not the pressure of the refrigerant in the refrigerant circuit has decreased below a predetermined pressure value (step S306). If it is determined that the pressure has not decreased (step S306; N), the control device 20 returns to step S305, and continues to stop the compressor 1 and open the expansion valve 4. The predetermined pressure value may be determined as a pressure at which the refrigerant pressure in the refrigerant circuit does not cause a disproportionation reaction, and is not uniformly determined.

When it is determined that the pressure has decreased (step S306; Y), the control device 20 restarts the compressor 1 (step S307). That is, the controller 20 determines that the HFO-1123 does not cause a disproportionation reaction even after the compressor 1 is started up, controls the compressor 1 normally, and returns to step S101.

As described above, in the refrigeration cycle apparatus 100C, after the start-up of the compressor 1, disproportionation reaction suppression that suppresses the increase in the rotational speed of the compressor 1 so as not to exceed the disproportionation reaction pressure value of HFO-1123. Take control. Therefore, according to the refrigeration cycle apparatus 100C, even when HFO-1123 is used, the refrigerant circuit is within a pressure range in which HFO-1123 does not disproportionate based on the discharge gas pressure of the compressor 1 and the condenser outlet pressure. It becomes possible to control the pressure. Further, according to the refrigeration cycle apparatus 100A, it is possible to accurately suppress the disproportionation reaction of HFO-1123 by detecting the condenser outlet pressure.

Furthermore, since the refrigeration cycle apparatus 100C can effectively utilize the pressure range in which the disproportionation reaction can be suppressed, even if a mixed refrigerant is used as the working refrigerant, the ratio of refrigerants other than HFO-1123 can be reduced. Therefore, according to the refrigeration cycle apparatus 100C, the ratio of the refrigerant other than HFO-1123 to be mixed can be minimized, the increase in product cost can be suppressed, and the product weight can be increased (unit size increased). Can also be suppressed.

As described above, the refrigeration cycle apparatus according to the present invention has been described by dividing it into three embodiments. However, the present invention is not limited thereto, and various modifications or changes can be made without departing from the scope and spirit of the present invention. Moreover, you may comprise the refrigerating-cycle apparatus combining the content demonstrated in each embodiment suitably.

Note that the refrigeration cycle apparatus described in each embodiment is applied to an apparatus equipped with a refrigeration cycle, such as an air conditioner (for example, a refrigeration apparatus, a room air conditioner, a packaged air conditioner, a multi air conditioner for buildings), a heat pump water heater, and the like. Can be used.

1 compressor, 2 way valve, 3rd heat exchanger, 4 expansion valve, 5 second heat exchanger, 10 discharge pressure sensor, 11 discharge temperature sensor, 12 condenser outlet pressure sensor, 13 condenser outlet temperature sensor, 14 outside air temperature sensor, 15 water outlet temperature sensor, 20 control device, 30 refrigerant piping, 100A refrigeration cycle device, 100B refrigeration cycle device, 100C refrigeration cycle device.

Claims

A refrigeration cycle apparatus having a refrigerant circuit in which at least a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected by piping, and the refrigerant circuit is filled with a refrigerant containing HFO-1123,
At the time of starting the compressor, the refrigerant disproportionation reaction pressure obtained from the discharge gas temperature of the refrigerant discharged from the compressor and the condenser outlet temperature of the refrigerant discharged from the condenser A refrigeration cycle apparatus that suppresses the rotational speed of the compressor based on the value.
The refrigeration cycle apparatus according to claim 1, wherein an increase in the rotation speed of the compressor is suppressed so as not to exceed the disproportionation reaction pressure value.
The refrigeration cycle apparatus according to claim 1 or 2, wherein a startup pattern of the compressor is determined so as not to exceed the disproportionation reaction pressure value.
The condenser exchanges heat between the refrigerant and air;
The startup pattern of the compressor is determined so as not to exceed the disproportionation reaction pressure value by estimating the pressure after startup of the compressor based on the outside air temperature before startup of the compressor. The refrigeration cycle apparatus according to any one of the above.
The evaporator exchanges heat between the refrigerant and water;
The pressure after the start of the compressor is estimated from the water temperature before the start of the compressor, and the start pattern of the compressor is determined so as not to exceed the disproportionation reaction pressure value. The refrigeration cycle apparatus according to any one of the above.
After starting the compressor, when the pressure in the refrigerant circuit after starting becomes equal to or greater than the disproportionation reaction pressure value,
The refrigeration cycle apparatus according to any one of claims 1 to 5, wherein the compressor is stopped, the expansion valve is opened, the pressure in the refrigerant circuit is reduced, and then the compressor is started again.