JP2021135035A - Refrigerant leakage state determination method, refrigerant leakage state determination device and refrigerant leakage state monitoring system - Google Patents

Abstract

To provide a refrigerant leakage state determination method which can determine a leakage state including a leakage degree while continuing a normal operation without imposing a constriction on an operation state, in a heat pump having a refrigerant circulation path for making a refrigerant circulate therein, a refrigerant leakage state determination device which can perform the determination method, and a refrigerant leakage state monitoring system.SOLUTION: A refrigerant leakage state determination method includes a refrigerant leakage degree determination process for determining that a leakage degree of a refrigerant is in a middle-degree leakage state in the case that an overcooling degree calculated in an overcooling degree calculation process is zero in a state that an overcooling degree maintenance process is performed, an operation evaporator average opening derived in an operation evaporator average opening derivation process exceeds a reference average opening by a prescribed value exceeding an average opening being the operation evaporator average opening in a rated condition at a normal operation, and is smaller than a maximum average opening being a maximum value of the operation evaporator average opening, and an overheat degree calculated in an overheat degree calculation process is maintained at a reference overheat degree.SELECTED DRAWING: Figure 1

Description

The present invention includes a compressor that compresses the refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expansion valve that expands the refrigerant condensed by the condenser, and a refrigerant expanded by the expansion valve. A method for determining a refrigerant leakage state in a heat pump device including an evaporator for evaporating the refrigerant, the compressor, the condenser, the expansion valve, and the refrigerant circulation path for circulating the refrigerant in the order described in the expander, and the method used thereof. The present invention relates to a refrigerant leakage state determination device and a refrigerant leakage state monitoring system.

Conventionally, a compressor that compresses the refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expansion valve that expands the refrigerant condensed by the condenser, and an evaporator that evaporates the refrigerant expanded by the expansion valve. An air conditioner for determining the presence or absence of refrigerant leakage in a heat pump device including a compressor, a condenser, an expansion valve, and a refrigerant circulation path for circulating a refrigerant in the order described in the above is known (Patent Documents). 1).
In an operation mode in which the air conditioner is operated under predetermined refrigerant leakage determination conditions, the operating state changes according to the fluctuation of the refrigerant supercooling degree at the outlet of the heat source side heat exchanger (condenser in the cooling operation). The presence or absence of refrigerant leakage is determined based on the amount.

Japanese Patent No. 4270197

Although the technique disclosed in Patent Document 1 can determine the presence or absence of refrigerant leakage, it is necessary to operate under predetermined refrigerant leakage determination conditions. Therefore, when making the determination, the heat pump device is used for air conditioning. There was room for improvement because it could not be provided and the use of users was restricted.
Further, the technique disclosed in Patent Document 1 has a problem that it is not possible to appropriately know the degree of leakage such as the degree of leakage of the refrigerant.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a heat pump device having a refrigerant circulation path for circulating a refrigerant, while continuing normal operation without restricting the operating state, and leaking. It is an object of the present invention to provide a refrigerant leakage state determination method capable of determining a leakage state including a degree, a refrigerant leakage state determination device capable of executing the determination method, and a refrigerant leakage state monitoring system.

The method for determining the refrigerant leakage state for achieving the above object is
A compressor that compresses the refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expansion valve that expands the refrigerant condensed by the condenser, and evaporation that evaporates the refrigerant expanded by the expansion valve. A method for determining a refrigerant leakage state in a heat pump device including a device, a compressor, a condenser, an expansion valve, and a refrigerant circulation path for circulating a refrigerant in the order described in the evaporator.
A superheat degree calculation step of calculating the superheat degree by subtracting the evaporation temperature from the refrigerant suction temperature at the compressor inlet, and
A supercooling degree calculation step of calculating the supercooling degree by subtracting the refrigerant temperature at the condenser outlet from the condensation temperature, and
In the case of having at least one or more of the evaporators, the value obtained by converting the expansion valve opening degree based on the capacity ratio of the evaporators with respect to the evaporators in operation and the expansion valves corresponding to the evaporators. The operation evaporator average opening derivation process for deriving the operation evaporator average opening as an average value, and
A superheat degree maintenance process that maintains the superheat degree to the standard superheat degree during normal operation,
In the state where the superheat degree maintenance step is executed, the supercooling degree calculated in the supercooling degree calculation step is zero, and the operation evaporator derived in the operation evaporator average opening degree derivation step. The average opening exceeds the reference average opening that exceeds the average opening which is the average opening of the operating evaporator under the rated conditions during the normal operation by a predetermined value, and is the maximum value of the average opening of the operating evaporator. When the degree of superheat is less than the maximum average opening degree and the degree of superheat calculated in the above-mentioned superheat degree calculation step is maintained at the standard degree of superheat, the degree of leakage of the refrigerant is determined to be a moderate leakage state. The point is that it includes the process.

The refrigerant leakage state determination device for achieving the above objectives is
A compressor that compresses the refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expansion valve that expands the refrigerant condensed by the condenser, and evaporation that evaporates the refrigerant expanded by the expansion valve. A refrigerant leakage state determination device in a heat pump device including a device, a compressor, a condenser, an expansion valve, and a refrigerant circulation path for circulating a refrigerant in the order described in the evaporator, wherein the characteristic configuration is as follows.
A superheat degree calculation unit that calculates the superheat degree by subtracting the evaporation temperature from the refrigerant suction temperature at the compressor inlet.
A supercooling degree calculation unit that calculates the degree of supercooling by subtracting the refrigerant temperature at the outlet of the condenser from the condensation temperature,
In the case of having at least one or more of the evaporators, the value obtained by converting the expansion valve opening degree based on the capacity ratio of the evaporators with respect to the evaporators in operation and the expansion valves corresponding to the evaporators. An operation evaporator average opening derivation unit that derives the operation evaporator average opening as an average value, and
A superheat degree maintenance unit that maintains the superheat degree to the standard superheat degree during normal operation,
With the superheat degree maintaining unit executed, the supercooling degree calculated by the supercooling degree calculation unit is zero, and the operation evaporator derived by the operation evaporator average opening degree derivation unit. The average opening exceeds the reference average opening that exceeds the average opening which is the average opening of the operating evaporator under the rated conditions during the normal operation by a predetermined value, and is the maximum value of the average opening of the operating evaporator. When the degree of superheat is less than the maximum average opening degree and the degree of superheat calculated by the superheat degree calculation unit is maintained at the reference degree of superheat, the degree of leakage of the refrigerant is determined to be a moderate leakage state. The point is that it has a part.

The inventors have newly found that the combination of parameters related to the heat pump device changes peculiarly according to the leakage state of the refrigerant.
The above characteristic configuration is based on the above findings, and as shown in FIGS. 2, 3 and 4, the supercooling degree calculated in the supercooling degree calculation step is zero in the state where the superheating degree maintaining step is executed. Moreover, the average opening degree of the operating evaporator derived in the operation evaporator average opening degree derivation process exceeds the reference average opening degree and is less than the maximum average opening degree, and is superheated calculated in the superheat degree calculation process. It was newly found that when the degree is maintained at the standard superheat degree, the degree of leakage of the refrigerant can be said to be a moderate leakage state.
As a result, for example, as an administrator of a heat pump device, when actually inspecting the device, the degree of leakage is less than that of the medium leakage state, and the degree of leakage is less than that of the device, including no leakage. A medium leak state, which makes it easy to detect whether a leak has occurred, can be positively detected as a leak state.
Further, since the determination of the leakage state can be used regardless of whether the heat pump device is operated at a rated load or a medium load, for example, there are no operational restrictions on the user side of the heat pump device. Since it can be executed without applying it, the degree of freedom of operation can be improved as compared with the conventional leak judgment.
Based on the above, in a heat pump device having a refrigerant circulation path that circulates a refrigerant, a refrigerant leakage state determination method capable of determining a leakage state including the degree of leakage while continuing normal operation without restricting the operation state, and a refrigerant. A leak state determination device can be realized.

Further, the expansion valve opening degree can be an "expansion valve area" in addition to the "number of steps" indicating the opening degree of the expansion valve in the actual machine. Hereinafter, an example of the numerical value of the average opening degree of the operating evaporator when "expansion valve area" is used as a parameter corresponding to the opening degree of the expansion valve is shown.
For example, [Table 1] shows an example of the operating state under the rated conditions when four evaporators are connected. # 1 and # 2 are examples of evaporators having a relatively large capacity, and # 3 and # 4 are examples of evaporators having a relatively small capacity.
The simple average of the underlined part = 10 mm ² , and the value under this rated condition is 100%.

[Table 1]

Next, an example of the operating state under other conditions is shown in [Table 2]. The simple average of the underlined part = 10 mm ² , and the area ratio is 100%.

[Table 2]

Here, the average opening degree of the operating evaporator is a value in which the value during rated operation during normal operation is set to 100%, and not only the simple average but also the capacity of the indoor heat exchanger (condenser during heating operation). Alternatively, the average may be weighted by the capacity (capacity) of the evaporator during the cooling operation.

Further features of the refrigerant leakage state determination method are
The refrigerant leakage degree determination step is
In the state where the superheat degree maintenance step is executed, the supercooling degree calculated in the supercooling degree calculation step is a value larger than zero, and the supercooling degree derived in the operation evaporator average opening degree derivation step is derived. When the average opening degree of the operating evaporator is less than the maximum average opening degree and the degree of superheating calculated in the degree of superheat calculation step is maintained at the reference degree of superheat, the degree of leakage of the refrigerant is moderately leaked. The point is that it is determined that there is a small amount of leakage, including no leakage, which is less than the state.

According to the above-mentioned feature configuration, it can be seen that the leakage state of the refrigerant is a small leakage state in which the amount of leakage is relatively small. It is possible to judge that it is a leak. As a result, it is possible to increase the options for the administrator to take action after knowing the judgment result, reduce the burden on the administrator, and take appropriate measures according to the leakage state at the site.

Further features of the refrigerant leakage state determination method are
The refrigerant leakage degree determination step is
In the state where the superheat degree maintaining step is executed, the supercooling degree calculated in the supercooling degree calculation step is zero, and the operating evaporator derived in the operating evaporator average opening degree derivation step. When the average opening degree is the maximum average opening degree and the superheat degree calculated in the superheat degree calculation step is larger than the reference superheat degree, the degree of leakage of the refrigerant is greater than that in the medium leakage state. The point is that it is judged to be in a leaked state to some extent.

According to the above-mentioned feature configuration, it can be seen that the leakage state of the refrigerant is a large amount of leakage state in which the amount of leakage is relatively large. It is possible to judge that it is a leak, etc., and it is possible to lead to a prompt response after the judgment.

Further features of the refrigerant leakage state determination method are
The refrigerant leakage degree determination step is
The combination of the values of the degree of supercooling, the average opening degree of the operating evaporator, and the degree of superheat is other than the combination of the values specified in the medium leakage state, the small leakage state, and the large leakage state. In this case, the heat pump device is excluded from the determination of the degree of leakage because the operating state is different from the normal operation.

For example, when the heat pump device is not in the normal operation state immediately after the start of operation, the superheat degree is higher than the standard superheat degree even though the operation evaporator average opening degree is about the reference average opening degree. May become.
According to the above feature configuration, the accuracy of determining the leak state can be improved by excluding such a case from the determination of the leak state.

Further features of the refrigerant leakage state determination method are
The refrigerant leakage degree determination step is
The point is that the average opening degree of the operating evaporator derived in the step of deriving the average opening degree of the operating evaporator is corrected to a higher side as the evaporation pressure, which is the inlet pressure of the compressor, increases.

As shown in FIG. 7, in the case of leakage (the leakage rate is 40% in FIG. 7), the higher the evaporation pressure, which is the inlet pressure of the compressor, the higher the average opening degree of the operating evaporator. I got the finding that there is a tendency.
According to the above characteristic configuration, the operating evaporator average opening derived in the operation evaporator average opening derivation step is corrected to a higher side as the evaporation pressure, which is the inlet pressure of the compressor, increases, so that the evaporation pressure is higher. Even in this case, the degree of leakage of the refrigerant can be effectively determined.
As can be seen from FIG. 7, the inventors have confirmed that such a tendency is substantially the same regardless of whether the load is a rated load or an intermediate load.

Further features of the refrigerant leakage state determination method are
The refrigerant leakage degree determination step is
From the average opening degree of the operating evaporator and the evaporation pressure derived in the step of deriving the average opening degree of the operating evaporator, the leakage rate is derived by dividing the leakage amount of the refrigerant by the regular filling amount without leakage of the refrigerant. At the point.

According to the above characteristic configuration, the amount of refrigerant leakage is divided by the regular filling amount without refrigerant leakage from the operation evaporator average opening and evaporation pressure derived in the operation evaporator average opening derivation step. Since the leakage rate can also be derived, a more quantitative determination of the leakage state can be performed numerically, and more appropriate post-processing can be executed based on the value.

Further features of the refrigerant leakage state determination method are
The refrigerant leakage degree determination step is
The point is that the average opening degree of the operating evaporator derived in the step of deriving the average opening degree of the operating evaporator is corrected to a higher side as the degree of superheat increases.

As shown in FIG. 6, the inventors have found that when there is a leak (the leak rate is 40% in FIG. 6), the higher the degree of superheat, the higher the average opening degree of the operating evaporator tends to be.
According to the above characteristic configuration, the average opening degree of the operating evaporator derived in the average opening degree of the operating evaporator is corrected to the higher side as the degree of superheat increases, so that regardless of the value of the degree of superheat (reference degree of superheat). , The degree of refrigerant leakage can be determined more accurately.
As can be seen from FIG. 6, the inventors have confirmed that such a tendency is substantially the same regardless of whether the load is a rated load or an intermediate load.

Furthermore, as a refrigerant leakage state determination system,
In addition to being equipped with the above-mentioned refrigerant leakage state determination device
A monitoring device that is electrically connected to the heat pump device via a network line is provided.
It is preferable that the monitoring device is configured to monitor the degree of leakage of the refrigerant.

According to the above-mentioned feature configuration, since the leakage determination can be executed by remote monitoring, the workload related to the determination can be sufficiently reduced as compared with the case where the manager goes to each site to execute the leakage determination.

It is a schematic block diagram of the refrigerant leakage state determination device and the refrigerant leakage state monitoring system which concerns on 1st Embodiment. It is a graph which shows the result of having derived the relationship between a leakage rate and a supercooling degree by calculation. It is a graph which shows the result of deriving the relationship between the leakage rate and the average opening degree of an operating evaporator by calculation. It is a graph which shows the result of deriving the relationship between the leakage rate and the degree of superheat by calculation. It is a graph which shows the result of deriving the relationship between the leakage rate and the degree of supercooling when the parameter such as a condensation pressure is changed by calculation. It is a graph which shows the influence which superheat degree has on the average opening degree of an operation evaporator. It is a graph which shows the influence which the compressor inlet pressure (evaporation pressure) has on the operation evaporator average opening degree. It is a graph for deriving the leakage rate in a small / medium leakage state from the evaporation pressure and the average opening degree of the operating evaporator. It is a schematic block diagram of the refrigerant leakage state determination device and the refrigerant leakage state monitoring system which concerns on another embodiment. It is a graph which shows the result of deriving the relationship between the supercooling degree of a supercooler outlet and the refrigerant filling amount (leakage amount) by calculation. It is a graph which shows the result of deriving the relationship between the supercooling degree of a condenser outlet and the refrigerant filling amount (leakage amount) by calculation. It is a graph which shows the result of having derived the relationship between the operation evaporator average opening degree and the refrigerant charge amount (leakage amount) by calculation.

The refrigerant leakage state determination method according to the embodiment of the present invention, the refrigerant leakage state determination device 100 capable of executing the determination method, and the refrigerant leakage state monitoring system 200 are operating states in a heat pump device having a refrigerant circulation path for circulating refrigerant. The present invention relates to a device capable of determining the leakage state including the degree of leakage while continuing normal operation without any restrictions.
Hereinafter, embodiments thereof will be described with reference to FIGS. 1 to 8.

As shown in FIG. 1, the heat pump device H according to the refrigerant leakage state determination device 100 according to the embodiment condenses the compressor 11 that is rotationally driven by the engine 14 to compress the refrigerant and the refrigerant compressed by the compressor 11. The compressor, the expansion valve V that expands the refrigerant condensed by the condenser, the evaporator that evaporates the refrigerant expanded by the expansion valve V, the compressor 11, the condenser, the expansion valve V, and the evaporator. A refrigerant circulation path C1 that circulates the refrigerant in the order described is provided. That is, in the embodiment, the refrigerant circulation path C1 is provided without a receiver for storing the refrigerant.
The refrigerant circulation path C1 has a four-way valve 20 that switches the refrigerant circulation state between a cooling operation (an operation that exerts a cooling capacity in an evaporator) and a heating operation (an operation that exerts a heating capacity in a condenser). Is provided.
Further, an accumulator 15 for storing the refrigerant is provided at the inlet of the compressor 11 to prevent the refrigerant in the liquid phase state from being guided to the compressor 11.
Further, an oil separator 16 for separating the oil mixed into the refrigerant pipe from the compressor 11 from the refrigerant is provided at the outlet of the compressor 11, and an oil flow for communicating and connecting the oil separator 16 and the inlet of the compressor 11. An oil valve V3 that opens and closes the passage Lo and the oil flow path Lo is provided, and the oil stored in the oil separator 16 periodically shifts the oil valve V3 from the closed state to the open state. You will be guided to the entrance of 11.

During the cooling operation, as shown in FIG. 1, the refrigerant flowing through the refrigerant circulation path C1 exchanges heat between the outdoor air blown by the compressor 11, the oil separator 16, and the fan (not shown) and the refrigerant. The order described in the heat exchanger 12 (corresponding to the compressor), the expansion valve V, and the indoor heat exchanger 13 (corresponding to the evaporator) that exchanges heat between the indoor air blown by the fan (not shown) and the refrigerant. The four-way valve 20 is switched so as to circulate.
On the other hand, during the heating operation, although not shown, the refrigerant flowing through the refrigerant circulation path C1 exchanges heat between the indoor air blown by the compressor 11, the oil separator 16, and the fan (not shown) and the refrigerant. Described in the indoor heat exchanger 13 (corresponding to a compressor), the expansion valve V, and the outdoor heat exchanger 12 (corresponding to an evaporator) that exchanges heat between the outdoor air blown by a fan (not shown) and the refrigerant. The four-way valve 20 is switched so as to circulate in order. In many cases, a heat exchanger that evaporates a part of the refrigerant by using the exhaust heat of the engine 14 is also installed, but the illustration is omitted.

Further, the refrigerant leakage state determination device 100 according to the embodiment has the following configuration in order to measure various parameters of the heat pump device H.
The refrigerant leakage state determination device 100 calculates the superheat degree by subtracting the evaporation temperature from the refrigerant suction temperature at the inlet of the compressor 11 as the control device S realized by the cooperation of hardware and software. A supercooling degree calculation unit S2 that calculates the degree of supercooling by subtracting the refrigerant temperature at the outlet of the condenser from the condensing temperature, and an evaporator that is operating when at least one or more evaporators are provided. With respect to the expansion valve V corresponding to (indoor heat exchanger 13), the operating evaporator average as the average value of the expansion valve opening degree converted based on the capacity ratio of the evaporator (value divided in the embodiment). It has an operation evaporator average opening degree deriving unit S3 for deriving the opening degree.
In this specification, since the case of cooling operation is described as an example, the evaporator is described as the indoor heat exchanger 13, but the method for determining the refrigerant leakage state of the present invention is suitable even in heating operation. Can be applied, and in the case of heating operation, the evaporator becomes the outdoor heat exchanger 12.
Further, the control device S functions as a superheat degree maintaining unit (not shown) that maintains the superheat degree at a predetermined reference superheat degree (5K in the calculation result described later) when the heat pump device H is operated in the normal operation state. do.

By the way, the refrigerant leakage state determination device 100 according to the embodiment is configured as follows in order to determine the leakage state including the degree of leakage while continuing the normal operation without restricting the operation state. ..

In the refrigerant leakage state determination device 100, the supercooling degree calculated by the supercooling degree calculating unit S2 is calculated in a state where the superheating degree maintaining unit is executing the superheating degree maintaining step of maintaining the superheating degree as the control device S. The average opening degree of the operating evaporator, which is zero and is derived by the operating evaporator average opening degree deriving unit S3, is the average opening degree of the operating evaporator under the rated conditions during normal operation (in FIG. 3). 100%) exceeds the standard average opening (125% in FIG. 3, L1) that increases by a predetermined value (about 25% in the example of FIG. 3) and less than the maximum average opening which is the maximum value of the operating evaporator average opening. Therefore, when the superheat degree calculated by the superheat degree calculation unit S1 is maintained at the reference superheat degree, the refrigerant that executes the refrigerant leakage degree determination step of determining that the degree of leakage of the refrigerant is a moderate leakage state. It has a leakage degree determination unit S5.

The refrigerant leakage degree determination unit S5 is configured to be capable of executing a small degree of leakage state determination and a large degree of leakage state determination in addition to the above-mentioned medium leakage state determination as a refrigerant leakage state determination method. ..
To add an explanation, in the refrigerant leakage degree determination unit S5, the supercooling degree calculated in the supercooling degree calculation step is a value larger than zero in the state where the superheat degree maintaining step is being executed, and the operating evaporator. Refrigerant when the average opening degree of the operating evaporator derived in the average opening degree derivation step is less than the maximum average opening degree and the superheating degree calculated in the superheating degree calculation step is maintained at the reference superheating degree. It is judged that the degree of leakage is less than that of the medium leakage state and that the leakage state is a small degree including no leakage.
Further, in the refrigerant leakage degree determination unit S5, the supercooling degree calculated in the supercooling degree calculation step is zero in the state where the superheat degree maintaining step is executed, and in the operation evaporator average opening degree derivation step. When the derived operation evaporator average opening is the maximum average opening and the superheating degree calculated in the superheating degree calculation process is larger than the standard superheating degree, the degree of leakage of the refrigerant is larger than that in the medium leakage state. It is determined that there is a degree of leakage.

Further, the refrigerant leakage degree determination step will be described in detail based on the simulation results of FIGS. 2, 3 and 4. In the graph, □ indicates a reference value in the rated cooling operation.
The inventors performed a simulation of the heat pump device H simulating a direct expansion GHP of 20 HP in the case of a simple flow. In this simulation, the cooling mode in the compression refrigeration cycle is targeted.
As a component constituting the heat pump device H, the compressor 11 is fixed at a volume efficiency of 90%, the oil separator 16 is set in a space having a volume of about 4 L, and the condenser (outdoor heat exchanger 12) is set. Simulating the number of stages 54, the number of rows 3, and the number 2, a simple path allocation is set with a fin tube type with an inner diameter of 6.8 mm and a length of 1600 mm, and the liquid pipe as the refrigerant circulation path C1 has an inner diameter of 13.9 mm. The length is set to 50 m, the expansion valve V uses one that can change the area of the orifice on the pipe, and the evaporator (indoor heat exchanger 13) simulates the number of stages 18, the number of rows 3, and the number 4, and the inner diameter. A fin tube type with a length of 4.6 mm and a length of 2200 mm, set with a simple path split, the gas pipe as the refrigerant circulation path C1 is set with an inner diameter of 26.6 mm and a length of 50 m, and the accumulator 15 is about 8 L. It was set in the space of the volume of.
In the above description, the number of condensers (outdoor heat exchangers 12) is 2, which indicates that one heat exchanger is arranged on the front surface and one on the back surface of the outdoor heat exchanger 12. ..
On the other hand, in the above description, the number of evaporators (indoor heat exchangers 13) is 4, which corresponds to the number of indoor heat exchangers 13 to be connected. Under the rated conditions, the refrigerant flows through all the indoor heat exchangers 13, but under partial load or the like, the refrigerant flows only through some of the indoor heat exchangers 13. In this specification, it is expressed by the ratio of the number of evaporators in operation, and the rated condition is set to 100%, and the intermediate load described later is set to 50%.
Next, as the calculation conditions, the condensation pressure is 2.9 MPaA, the ratio of the number of operating units of the evaporator is 100%, the outside air temperature is 35 ° C., the degree of superheat is 5K, the evaporation pressure is 0.75 MPaA, and the degree of supercooling at the standard filling amount. Is 5K (at 17.5kg), the upper limit of the average opening of the operating evaporator is 100% when the degree of supercooling (5K) is 300%, the heat insulation efficiency of the compressor 11 is 80%, the refrigerant is R410A, and the refrigerant is filled. The amount was 110% to 30% (refrigerant leakage rate was -10% to 70%).
In the specification, unless otherwise specified, the average opening degree of the operating evaporator is shown as 100% when the rated operation is performed during the normal operation.

FIG. 2 is a graph showing the relationship between the refrigerant leakage rate and the degree of supercooling, FIG. 3 is a graph showing the relationship between the refrigerant leakage rate and the average opening degree of the operating evaporator, and FIG. 4 is a graph showing the relationship between the refrigerant leakage rate and the degree of superheating. Is.
From the simulation results, in a state of a small amount of leakage (in FIGS. 2, 3 and 4 the leakage rate is 0% or more and less than the first threshold value R1 (value of about 15%)), the superheat degree maintenance step is executed. The degree of supercooling is a value larger than zero as shown in FIG. 2, and the average opening degree of the operating evaporator is less than the reference average opening degree (L1 in FIG. 3) as shown in FIG. It can be seen that the degree is maintained at the reference superheat degree (5K in FIG. 4) as shown in FIG.
In a moderate leakage state (in FIGS. 2, 3 and 4, the leakage rate is 1% or more than the first threshold value R2 and less than the second threshold value R2 (value of about 50%)), supercooling is performed in a state where the superheat degree maintenance step is executed. The degree is zero as shown in FIG. 2, and the average opening degree of the operating evaporator exceeds the reference average opening degree (L1 in FIG. 3) and is less than the maximum average opening degree as shown in FIG. It can be seen that the degree of superheat is maintained at the reference degree of superheat (5K in FIG. 4) as shown in FIG.
In a large degree of leakage state (the leakage rate is the second threshold R2% or more in FIGS. 2, 3 and 4), the supercooling degree is zero as shown in FIG. 2 in the state where the superheat degree maintenance step is executed. Yes, and the average opening degree of the operating evaporator is the maximum average opening degree (300%) exceeding the reference average opening degree (L1 in FIG. 3) as shown in FIG. 3, and the degree of superheat is shown in FIG. As shown above, it can be seen that the value is larger than the standard superheat degree (5K in FIG. 4).
That is, in the refrigerant leakage state determination method according to the present invention, the determination of the refrigerant leakage state is executed based on the result of the above simulation.

The refrigerant leakage state determination device 100 according to the embodiment can determine the refrigerant leakage state if the operation state of the heat pump device H is not limited and is in the normal operation state.
However, for example, in the starting state of the heat pump device H (the state until the steady operation is reached), the combination of the above-mentioned various parameters shows an exceptional value. For example, in the starting state, the degree of superheat may show a high value exceeding the reference degree of superheat even though the opening of the average opening degree of the operating evaporator is not maximized.
Therefore, in the refrigerant leakage degree determination step, the refrigerant leakage degree determination unit S5 determines that the combination of the values of the supercooling degree, the operating evaporator average opening degree, and the superheat degree is a medium leakage state, a small leakage state, and a large leakage state. If the combination of values other than the value specified in the above is not specified, the heat pump device is excluded from the judgment of the degree of leakage because the operating state is different from the normal operation.

Next, the simulation results of the effects of changes in various environmental indicators and parameters on the degree of supercooling and the average opening degree of the operating evaporator will be described with reference to FIGS. 5, 6 and 7.
First, FIG. 5 showing the relationship between the degree of supercooling and the leakage rate shows that the condensation pressure is changed to 2.6 to 3.2 MPaA, the evaporator operating number ratio is 25% to 100%, and the outside air temperature is changed to 25 to 35 ° C. This is the result of the case. As can be seen from FIG. 5, the degree of supercooling changed significantly in the portion indicated by hatching. That is, it was found that in the case of a small amount of leakage (the degree of supercooling is positive), the degree of supercooling itself changes greatly depending on the condensation pressure, the operating number ratio, and the outside air temperature. However, the tendency that the degree of supercooling becomes greater than zero below the first threshold value R1 and the degree of supercooling becomes zero above the first threshold value R1 is generally maintained. As a result, in the relationship between the degree of supercooling and the leakage rate according to the present invention, it is not necessary to make corrections based on the condensation pressure, the ratio of the number of evaporators in operation, and the outside air temperature.

Next, FIG. 6 shows the relationship between the average opening degree of the operating evaporator and the degree of superheat. When the leakage rate is 40%, the rated load (outside air temperature 35 ° C., evaporator operating unit ratio 100%, condensation pressure 2.9 MPaA) and intermediate load (outside air temperature 30 ° C., evaporator operating unit ratio 50%, condensation pressure 2. In any case of 6 MPaA), it can be seen that the higher the degree of superheat, the lower the average opening degree of the operating evaporator tends to be.
Therefore, in the refrigerant leakage degree determination step, the refrigerant leakage degree determination unit S5 corrects the average opening degree of the operating evaporator to a higher side as the degree of superheat increases.
Since the rated load and the intermediate load have almost the same characteristics, it can be seen that the influence of the condensing pressure, the operating number ratio, and the outside air temperature is not large.

Next, FIG. 7 shows the relationship between the average opening degree of the operating evaporator and the inlet pressure (evaporation pressure) of the compressor 11. When the leakage rate is 40%, the rated load (outside air temperature 35 ° C., evaporator operating unit ratio 100%, condensation pressure 2.9 MPaA) and intermediate load (outside air temperature 30 ° C., evaporator operating unit ratio 50%, condensation pressure 2. In any case of 6 MPaA), it can be seen that the higher the evaporation pressure, the lower the average opening degree of the operating evaporator tends to be.
Therefore, in the refrigerant leakage degree determination step, the refrigerant leakage degree determination unit S5 corrects the average opening degree of the operating evaporator to a higher side as the evaporation pressure, which is the inlet pressure of the compressor 11, increases.
Since the rated load and the intermediate load have almost the same characteristics, it can be seen that the influence of the condensing pressure, the operating number ratio, and the outside air temperature is not large.

Further, the inventors have described, for example, the average opening degree of the operating evaporator and the evaporation pressure (in the leaking state excluding the large leakage state, that is, in the small leakage state and the medium leakage state in which the average opening degree of the operating evaporator changes. It has been newly added that the leakage rate (or the filling rate obtained by subtracting the leakage rate from 100%) can be derived from the inlet pressure of the compressor 11) by dividing the leakage of the refrigerant by the regular filling amount without leakage of the refrigerant. Found in.
Specifically, as shown in FIG. 8, in a graph in which the vertical axis represents the filling rate (100% -leakage rate) and the horizontal axis represents the average opening degree of the operating evaporator, the operating evaporation is performed for each evaporation pressure. We have obtained a graph diagram in which the filling rate decreases as the average opening degree of the vessel increases, in other words, a graph diagram in which the filling rate has a characteristic of multiplying the average opening degree of the operating evaporator.
Incidentally, the data of the graph shown in FIG. 8 is a value calculated from the results of the above-mentioned rated load condition and intermediate load condition having substantially the same characteristics. Further, the graph shown in FIG. 8 can be calculated by the following [Equation 1] under the above-described configuration and conditions.

[Equation 1]

Here, R: leakage rate, Pe: compressor inlet pressure (MPaA), Ev: average opening degree of operating evaporator (%), a = -0.98, b = 1.75, c = -0.06, d = 0.06, e = -0.72
It should be noted that the value is a value when the specific configuration of the heat pump device H described above is adopted, and changes if the system configuration is changed.

That is, since the refrigerant leakage degree determination unit S5 can determine the refrigerant leakage rate (or filling rate) in the refrigerant leakage degree determination step, the administrator can more accurately determine the leakage status based on the value. You can work on the restoration work while grasping. In FIG. 8, the leakage rate (filling) is obtained when the average opening degree of the operating evaporator is 120%, the compressor inlet pressure is 1.05 MPaA, and the compressor inlet pressure is 0.75 MPaA. The case of deriving the rate) is illustrated.

As shown in FIG. 1, the refrigerant leakage state determination device 100 according to the present invention can be configured as a refrigerant leakage state monitoring system including a monitoring device K via a network line N. In this configuration, the determination result determined by the refrigerant leakage degree determination unit S5 of the control device S can be constantly monitored by the monitoring device K, and the refrigerant does not go to the site where the heat pump device H is installed. The degree of leakage can be grasped.
Incidentally, the control device S may be provided with the heat pump device H integrally or as a part of the monitoring device K.

[Another Embodiment]
(1) As shown in FIG. 9, the refrigerant leakage state determination device 100, the refrigerant leakage state determination method, and the refrigerant leakage state determination system according to the present invention divide a part of the refrigerant circulating in the refrigerant circulation path C1. Even if the configuration includes a passage C2, an expansion valve V4 that expands and lowers the temperature of the diverted refrigerant, and a supercooler 17 that cools the refrigerant circulating in the refrigerant circulation path C1 with the refrigerant that has passed through the expansion valve V4 and lowered the temperature. It works well.
FIG. 9 shows an example of the circuit configuration of the distribution flow path C2 during the cooling operation.
In the following, only the configuration related to the distribution flow path C2, which is a configuration different from the above embodiment, will be described, and the configuration without explanation will be the same as the above embodiment.
As shown in FIG. 9, the upstream end of the distribution flow path C2 is connected to the refrigerant circulation path C1 between the supercooler 17 and the expansion valve V, and the downstream end is the accumulator 15 and the compressor 11. It is connected to the refrigerant circulation path C1 between them (more specifically, the refrigerant circulation path C1 between the downstream end of the oil flow path Lo and the accumulator 15).
In the distribution flow path C2, a flow path portion through which the refrigerant expanded by the expansion valve V4 passes is arranged so as to pass through the inside of the supercooler 17, thereby causing the refrigerant in the supercooler 17 to pass through. It cools the refrigerant circulating in the circulation path C1.
Here, the value obtained by dividing the flow rate of the refrigerant guided to the distribution flow path C2 by the flow rate of the refrigerant flowing through the outdoor heat exchanger 12 (value indicated by SC in FIGS. 10 to 12) is 8% (FIGS. 10 to 10). The relationship between the degree of supercooling at the outlet of the supercooler 17 and the amount of refrigerant charged when 12 is set to △), 4% (marked with □ in FIGS. 10 to 12), and 0% (marked with ◯ in FIGS. 10 to 12) is shown. FIG. 10 shows the relationship between the degree of supercooling at the outlet of the condenser and the refrigerant filling amount, and FIG. 12 shows the relationship between the expansion valve opening degree and the refrigerant filling amount.
According to the result, in the degree of supercooling at the outlet of the supercooler 17 (value shown in FIG. 10), the relationship between the degree of supercooling and the amount of refrigerant charged changes as the amount of refrigerant filled in the distribution flow path C2 changes. On the other hand, in the degree of supercooling at the outlet of the condenser (value shown in FIG. 11), the degree of supercooling and the amount of refrigerant charged are different regardless of the change in the amount of refrigerant filled in the distribution flow path C2. The relationship has not changed. For this reason, in the configuration including the supercooler 17, by adopting a configuration in which the degree of supercooling is derived at the outlet of the condenser, the refrigerant leaks regardless of the amount of the refrigerant distributed to the distribution flow path C2. It can be seen that the state can be appropriately determined.
Further, it can be seen from FIG. 12 that the distribution amount to the distribution flow path C2 has almost no effect on the relationship between the expansion valve opening degree and the refrigerant filling amount.

(2) The values of the reference average opening degree L1, the threshold value R1, and the threshold value R2 described above are values that change depending on the operating conditions and the system configuration, and the values shown in the above embodiments are examples, and the values shown in the above embodiment are examples of the present invention. The embodiment is not limited to this value.

(3) In the above embodiment, in addition to the medium leakage state, a configuration for determining a small leakage state and a large leakage state is shown, but a configuration for detecting only a medium leakage state may be adopted. ..

(4) In the above embodiment, an example is shown in which the average opening degree of the operating evaporator is corrected by the degree of superheat and the average opening degree of the operating evaporator is corrected by the inlet pressure of the compressor, but these corrections are not executed. It doesn't matter.

(5) In the above embodiment, the engine-driven heat pump device according to the present invention has been described as an example, but the refrigerant leakage state determination method, the refrigerant leakage state determination device, and the refrigerant leakage state monitoring system according to the present invention are driven by a motor. Even a type heat pump device can be effectively used.

(6) To determine the degree of leakage, the supercooling degree calculated in the supercooling degree calculation step is a value larger than zero while the superheat degree maintaining step is being executed, and the average opening of the operating evaporator is performed. Leakage of refrigerant when the average opening degree of the operating evaporator derived in the degree derivation process is less than the reference average opening degree and the degree of superheating calculated in the degree superheating degree calculation process is maintained at the reference degree of superheating degree. The configuration may be such that the degree of leakage is less than that of the medium leakage state, and the degree of leakage is determined to be small.

The configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

The refrigerant leakage state determination device and the refrigerant leakage state monitoring system of the present invention are a heat pump device having a refrigerant circulation path that circulates the refrigerant, and leaks including the degree of leakage while continuing normal operation without restricting the operation state. It can be effectively used as a refrigerant leakage state determination method capable of determining the state, a refrigerant leakage state determination device capable of executing the determination method, and a refrigerant leakage state monitoring system.

11: Compressor 12: Outdoor heat exchanger 13: Indoor heat exchanger 100: Refrigerant leakage state determination device 200: Refrigerant leakage state monitoring system C1: Refrigerant circulation path H: Heat pump device K: Monitoring device N: Network line S: Control Device S1: Superheat degree calculation unit S2: Overcooling degree calculation unit S3: Operating evaporator average opening lead-out unit S5: Refrigerant leakage degree determination unit V: Expansion valve

Claims (10)

A compressor that compresses the refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expansion valve that expands the refrigerant condensed by the condenser, and evaporation that evaporates the refrigerant expanded by the expansion valve. A method for determining a refrigerant leakage state in a heat pump device including a device, a compressor, a condenser, an expansion valve, and a refrigerant circulation path for circulating a refrigerant in the order described in the expander.
A superheat degree calculation step of calculating the superheat degree by subtracting the evaporation temperature from the refrigerant suction temperature at the compressor inlet, and
A supercooling degree calculation step of calculating the supercooling degree by subtracting the refrigerant temperature at the condenser outlet from the condensation temperature, and
In the case of having at least one or more of the evaporators, the value obtained by converting the expansion valve opening degree based on the capacity ratio of the evaporators with respect to the evaporators in operation and the expansion valves corresponding to the evaporators. The operation evaporator average opening derivation process for deriving the operation evaporator average opening as an average value, and
A superheat degree maintenance process that maintains the superheat degree to the standard superheat degree during normal operation,
In the state where the superheat degree maintenance step is executed, the supercooling degree calculated in the supercooling degree calculation step is zero, and the operation evaporator derived in the operation evaporator average opening degree derivation step. The average opening exceeds the reference average opening that exceeds the average opening which is the average opening of the operating evaporator under the rated conditions during the normal operation by a predetermined value, and is the maximum value of the average opening of the operating evaporator. When the degree of superheat is less than the maximum average opening degree and the degree of superheat calculated in the above-mentioned superheat degree calculation step is maintained at the standard degree of superheat, the degree of leakage of the refrigerant is determined to be a moderate leakage state. A method for determining a refrigerant leakage state including a step. The refrigerant leakage degree determination step is
In the state where the superheat degree maintenance step is executed, the supercooling degree calculated in the supercooling degree calculation step is a value larger than zero, and the supercooling degree derived in the operation evaporator average opening degree derivation step is derived. When the average opening degree of the operating evaporator is less than the maximum average opening degree and the degree of superheating calculated in the degree of superheat calculation step is maintained at the reference degree of superheat, the degree of leakage of the refrigerant is moderately leaked. The method for determining a refrigerant leakage state according to claim 1, wherein the leakage state is determined to be a small degree of leakage including no leakage, which is less than the state. The refrigerant leakage degree determination step is
In the state where the superheat degree maintenance step is executed, the supercooling degree calculated in the supercooling degree calculation step is zero, and the operation evaporator derived in the operation evaporator average opening degree derivation step. When the average opening degree is the maximum average opening degree and the superheat degree calculated in the superheat degree calculation step is larger than the reference superheat degree, the degree of leakage of the refrigerant is greater than that in the medium leakage state. The method for determining a refrigerant leak state according to claim 1, wherein the refrigerant leak state is determined to be in a certain degree of leakage state. The refrigerant leakage degree determination step is
In the state where the superheat degree maintenance step is executed, the supercooling degree calculated in the supercooling degree calculation step is zero, and the operation evaporator derived in the operation evaporator average opening degree derivation step. When the average opening degree is the maximum average opening degree and the superheat degree calculated in the superheat degree calculation step is larger than the reference superheat degree, the degree of leakage of the refrigerant is greater than that in the medium leakage state. The method for determining a refrigerant leak state according to claim 2, wherein the refrigerant leak state is determined to be in a certain degree of leakage state. The refrigerant leakage degree determination step is
The combination of the supercooling degree, the operating evaporator average opening degree, and the superheating degree is other than the combination of the values specified in the medium leakage state, the small leakage state, and the large leakage state. In this case, the refrigerant leakage state determination method according to claim 4, wherein the operation state of the heat pump device is excluded from the determination of the degree of leakage because the operation state is different from the normal operation. The refrigerant leakage degree determination step is
Any one of claims 1 to 5 for correcting the average opening degree of the operating evaporator derived in the step of deriving the average opening degree of the operating evaporator to a higher side as the evaporation pressure, which is the inlet pressure of the compressor, increases. The method for determining a refrigerant leakage state according to. The refrigerant leakage degree determination step is
The leakage rate is derived by dividing the leakage amount of the refrigerant by the regular filling amount without leakage of the refrigerant from the average opening degree of the operation evaporator and the evaporation pressure derived in the operation evaporator average opening degree derivation step. The method for determining a refrigerant leakage state according to any one of claims 1 to 6. The refrigerant leakage degree determination step is
The refrigerant leakage state determination according to any one of claims 1 to 7, wherein the operation evaporator average opening degree derived in the operation evaporator average opening degree derivation step is corrected to a higher side as the degree of superheat increases. Method. A compressor that compresses the refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expansion valve that expands the refrigerant condensed by the condenser, and evaporation that evaporates the refrigerant expanded by the expansion valve. A refrigerant leakage state determination device in a heat pump device including a device, a compressor, a condenser, an expansion valve, and a refrigerant circulation path for circulating a refrigerant in the order described in the expander.
A superheat degree calculation unit that calculates the superheat degree by subtracting the evaporation temperature from the refrigerant suction temperature at the compressor inlet.
A supercooling degree calculation unit that calculates the degree of supercooling by subtracting the refrigerant temperature at the outlet of the condenser from the condensation temperature,
In the case of having at least one or more of the evaporators, the value obtained by converting the expansion valve opening degree based on the capacity ratio of the evaporators with respect to the evaporators in operation and the expansion valves corresponding to the evaporators. An operation evaporator average opening derivation unit that derives the operation evaporator average opening as an average value, and
A superheat degree maintenance unit that maintains the superheat degree to the standard superheat degree during normal operation,
With the superheat degree maintaining unit executed, the supercooling degree calculated by the supercooling degree calculation unit is zero, and the operation evaporator derived by the operation evaporator average opening degree derivation unit. The average opening exceeds the reference average opening that exceeds the average opening which is the average opening of the operating evaporator under the rated conditions during the normal operation by a predetermined value, and is the maximum value of the average opening of the operating evaporator. When the degree of superheat is less than the maximum average opening degree and the degree of superheat calculated by the superheat degree calculation unit is maintained at the reference degree of superheat, the degree of leakage of the refrigerant is determined to be a moderate leakage state. A refrigerant leakage state determination device having a unit. The refrigerant leakage state determination device according to claim 9 is provided, and the refrigerant leakage state determination device is provided.
A monitoring device that is electrically connected to the heat pump device via a network line is provided.
A refrigerant leakage condition monitoring system in which the monitoring device is configured to monitor the degree of leakage of the refrigerant.

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