JP2015206509A - Cooling / heating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide cold/hot heat equipment that detects leakage of refrigerant in early stage even without using an expensive sensor such as a gas sensor, and can locate a leakage section.SOLUTION: Cold/hot heat equipment 1 includes: a refrigeration cycle including a compressor 2; a condenser 4; an expansion valve 5 and an evaporator 6; at least three sensors 51, 52, 53 provided at positions separate from each other on the refrigeration cycle; and a control device 50 for determining a section where refrigerant leaks on the basis of values input from the sensors.

Description

  The present invention relates to a cold / hot apparatus.

  Conventionally, when a refrigerant such as hydrocarbon or a refrigerant such as R32 is used for an air conditioner, if the refrigerant leaks to the indoor side, the flammable concentration may be reached.

  For this reason, in the unlikely event that the refrigerant leaks, it is desirable to correctly detect the leaked section, take emergency measures according to the leaked section, and quickly restore it.

  Regarding detection of the leaked refrigerant, for example, as disclosed in Patent Document 1 and Patent Document 2, a method of judging a leak by using a refrigerant sensor (gas sensor) or detecting a refrigerant state by a temperature sensor or a pressure sensor. Has been proposed.

JP 2013-108641 A JP 2000-081258 A

  In Patent Document 1, leakage is indirectly detected by a gas sensor that directly detects refrigerant gas or an oxygen sensor that detects oxygen in the gas, and the leaked refrigerant can be reliably detected, but this type of sensor is expensive. In addition to this, the detection accuracy decreases due to the adhesion of dirt and aging.

  Moreover, in patent document 2, although the presence or absence of a refrigerant | coolant is judged by the temperature detected by the temperature sensor provided in the location where a liquid refrigerant accumulates, a leak can be detected without using an exclusive gas sensor, but a leak area is specified. I can't do it.

  This invention is made | formed in view of the said problem, and makes it a subject to provide the cooling / heating apparatus which can specify a leak area.

  In order to solve the above-described problems, the present invention provides a refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, and at least three sensors provided at spaced positions on the refrigeration cycle. And a control device that determines a section in which the refrigerant is leaking based on a value input from the sensor.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling / heating apparatus which can specify a leak area can be provided.

It is a block diagram of the refrigerating cycle of the air conditioner which concerns on 1st Embodiment. It is the graph which showed the time-dependent change of the temperature in a refrigerant | coolant temperature detection means at the time of a refrigerant | coolant leakage on the outdoor side for every leakage area. It is the graph which showed the time-dependent change of the temperature in a refrigerant | coolant temperature detection means when a refrigerant | coolant leakage generate | occur | produced indoors for every leakage area. It is a block diagram of the control mechanism regarding the leak determination and warning of a refrigerant | coolant of the air conditioner which concerns on 1st Embodiment. It is a flowchart of the leak determination which the control apparatus of the air conditioner concerning 1st Embodiment performs.

Hereinafter, a cooling / heating apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.
Hereinafter, the refrigerant in this embodiment is used for both cooling and heating. Similarly, the term “refrigeration cycle” in the following description refers to a refrigeration cycle that can be used for cooling and / or heating.
Moreover, although the cooling / heating apparatus which concerns on embodiment of this invention is demonstrated taking an air conditioner as an example, it is not restricted to this. The present invention can be applied to all apparatuses having a refrigeration cycle. Further, the refrigerant leakage in the stopped state from the cooling operation will be described as an example, but the refrigerant leakage in the stopped state from the heating operation can be considered in the same manner as in the cooling operation.
In addition, for convenience of explanation, members that are the same in each drawing may be given the same reference numerals, and redundant explanations may be omitted. The front / rear / up / down / left / right direction axes are as shown in the drawings.
The air conditioner described in the embodiment of the present invention includes a compressor, an outdoor heat exchanger, an outdoor blower, a four-way valve, and an expansion valve, and includes an outdoor unit installed outdoors and an indoor unit installed indoors. Are connected via a refrigerant connecting pipe, thereby enabling indoor air conditioning.

(First embodiment)
FIG. 1 is a configuration diagram of a refrigeration cycle of the air conditioner according to the first embodiment.
The air conditioner 1 includes a compressor 2, a flow path switching valve 3, a first heat exchanger 4, an expansion valve 5, and a liquid phase side stop valve (service valve) 8 (hereinafter referred to as "liquid side stop"). Valve 8 "), the second heat exchanger 6, and a gas phase side stop valve (service valve) 9 (hereinafter referred to as" gas side stop valve 9 ") in the refrigerant flow path are connected in an annular shape in this order. A known refrigeration cycle is configured to include the refrigerant circuit 10.

  Here, the outdoor unit 1 a includes a compressor 2, a flow path switching valve (for example, a four-way valve) 3, a first heat exchanger 4, and an expansion valve 5, and the indoor unit 1 b includes a second heat exchanger 6. Become. The outdoor unit 1a and the indoor unit 1b are connected by connecting pipes 1c and 1c, respectively. Moreover, the solid line arrow represents the direction in which the refrigerant flows during the cooling operation, and the broken line arrow represents the direction in which the refrigerant flows during the heating operation.

  The compressor 2 is a compressor, for example, and compresses the refrigerant flowing in from the suction side and discharges it from the discharge side. In the compressor 2, since the refrigerant is compressed, pressure loss occurs.

  A suction tank (S tank) 20 is disposed in the path on the inlet side of the compressor 2. The S tank 20 is installed on the inlet side of the compressor 2. Since the compressor 2 mainly compresses gas, the S tank 20 is installed as a buffer tank so that refrigerant droplets do not enter the compressor 2. Here, no pressure loss occurs.

  The 1st heat exchanger 4 is the heat exchanger provided in the outdoor unit 1a, and is also called a condenser. The high-temperature and high-pressure gas-phase refrigerant compressed by the compressor 2 and the outside air ventilated by the blower 7a are heat-exchanged by the first heat exchanger 4, and the refrigerant is condensed and undergoes phase transition. It becomes a liquid phase refrigerant.

  The first heat exchanger 4 has a structure in which thin refrigerant pipes are folded several times in order to promote heat exchange. For this reason, when the refrigerant passes through the first heat exchanger 4, a pressure loss occurs.

  The expansion valve 5 is a valve that decompresses and adiabatically expands the low-temperature and high-pressure liquid refrigerant. Since it is a decompression process, a pressure loss occurs when the refrigerant passes through the expansion valve 5. In the adiabatic expansion process, the temperature decreases. As a result, the refrigerant is cooled to a low temperature and a low pressure and is supplied to the indoor unit 1b.

  The 2nd heat exchanger 6 is a heat exchanger provided in the indoor unit 1b, and is also called an evaporator. The second heat exchanger 6 has a structure in which thin refrigerant pipes are folded several times in order to promote heat exchange. Therefore, when the refrigerant passes through the expansion valve 5, a pressure loss occurs.

  In the second heat exchanger 6, the low-temperature and low-pressure cooled liquid phase refrigerant that has passed through the expansion valve 5 and the indoor air ventilated by the blower 7b are heat-exchanged.

  At this time, the warm indoor air absorbs the heat of the cooled refrigerant, becomes cold air, and is supplied indoors (cooling operation). In addition, the cold refrigerant absorbs the heat of warm indoor air, evaporates, and evaporates (phase transition).

  The high-temperature and low-pressure refrigerant that has been vaporized into the gas phase is supplied again to the inlet side of the compressor 2, that is, the suction side, via the flow path switching valve 3.

  Here, for example, a four-way valve is used as the flow path switching valve 3. The flow path switching valve 3 needs to reverse the flow direction of the refrigerant, for example, in accordance with switching of the cooling / heating operation. At this time, around the compressor 2 (from the flow path switching valve 3 to the suction side of the compressor 2, In addition, it is installed to change only the direction of the refrigerant flow in the refrigerant circuit 10 without changing the direction of the refrigerant flow from the flow path switching valve 3 to the discharge side of the compressor 2.

  In addition, since the flow path switching valve 3 has a structure that completely changes the flow of the refrigerant without leakage, there are places where the flow path diameters are different inside. For this reason, the channel resistance is greatly different from other pipe diameters. Therefore, a pressure loss occurs when the refrigerant passes through this portion.

  In FIG. 1, the flow path switching valve 3 indicates the connection path during the cooling operation by a solid line. However, during the heating operation, the path indicated by the broken line may be connected.

  The liquid-side stop valve 8 and the gas-side stop valve 9 preliminarily enclose the refrigerant in the refrigerant circuit 10 of the outdoor unit 1a before installing the indoor unit 1b when the air conditioner 1 is installed. It is a valve to keep. Therefore, it is installed on the outdoor unit 1a side at the substantially same position as the connection port between the outdoor unit 1a and the connection pipe 1c. In addition, after installation, the valve is always fully open except during relocation or removal.

  Each of the liquid-side and gas-side stop valves 8 and 9 has a structure in which the flow path becomes narrow inside because the structure can completely stop the refrigerant without leakage. For this reason, even if the valve is fully open, the flow path resistance is larger than other pipes. Therefore, when the refrigerant passes through the stop valves 8 and 9 on the liquid side and the gas side, pressure loss, that is, adiabatic compression occurs.

In order to control the operation of the air conditioner 1 and the detection of refrigerant leakage, the air conditioner 1 is provided with a control device 50 (described later in detail) and refrigerant temperature detecting means 51 to 53.
Note that control lines and communication lines are omitted as appropriate in order to avoid complications in the figure.

  When the air conditioner 1 is operating, the control device 50 detects the refrigerant temperature by each refrigerant temperature detection means 51 to 53, sends a command to each control element, and controls the operation of the refrigeration cycle. When the operation is stopped, the refrigerant temperature is detected by the refrigerant temperature detecting means 51 to 53 at predetermined time intervals to determine whether or not the refrigerant has leaked.

  As the refrigerant temperature detecting means 51 to 53, for example, a temperature sensor such as a thermistor may be used which is brought into contact with the equipment surface or the pipe surface.

  The refrigerant temperature detection means 51 is installed in the upper part of the compressor 2, for example. The refrigerant temperature detection means 51 may be installed in the discharge pipe of the compressor 2. The refrigerant temperature detection means 51 includes the temperature of the compressor 2, that is, the refrigerant temperature in the path of the flow path switching valve 3 to the S tank 20 to the inlet of the compressor 2, and from the outlet of the compressor 2 to the flow path switching valve 3. Information that combines the refrigerant temperature of the path is collected.

  The refrigerant temperature detection means 52 is installed in the piping between the 1st heat exchanger 4 and the expansion valve 5, for example. The refrigerant temperature detection means 52 may be installed in the first heat exchanger 4.

  The temperature detection means 53 is installed on the outlet side of the second heat exchanger 6, for example. The temperature detecting means 53 may be installed in a pipe between the second heat exchanger 6 and the high pressure side stop valve 9.

  The blower 7a is a blower for exchanging heat between the refrigerant flowing in the refrigerant pipe of the first heat exchanger 4 and the air, and for example, a propeller fan or the like is used. The blower 7b is a blower for exchanging heat between the refrigerant flowing in the refrigerant pipe of the second heat exchanger 6 and the air, and for example, a cross-flow fan or the like is used.

  As described above, in this embodiment, the locations where pressure loss occurs are summarized as follows. That is, in the direction of refrigerant circulation during the cooling operation, the liquid side stop valve 8, the second heat exchanger 6, the gas side stop valve 9, the flow path switching valve 3, the compressor 2, the flow path switching valve 3, and the first. A pressure loss occurs in the heat exchanger 4 and the expansion valve 5. After these, the first liquid side stop valve 8 is returned to. Below, the location where these pressure losses occur may be referred to as “elements”.

  In the following, the boundary line that separates the indoor side and the outdoor side will be considered in terms of not a visual viewpoint but a point where pressure loss occurs. This is because the refrigerant temperature detection means 51 to 53 are used to capture the temperature change, and based on the result, it is desired to determine whether the leakage location is the indoor side or the outdoor side.

  Specifically, among the elements causing pressure loss, the line connecting the liquid side stop valve 8 and the gas side stop valve 9 is closest to the indoor / outdoor division when viewed visually. Suppose that this line is considered as an indoor / outdoor boundary (see FIG. 1).

  Next, referring to Table 1, for example, when the refrigerant leaks from the outdoor side gas side stop valve 9 to the flow path switching valve 3 when the cooling operation of the air conditioner 1 is stopped, the refrigerant A mechanism for generating a temperature difference in the temperature detection means 51 to 53 will be described (section C-1).

  In the present embodiment, for easy understanding of the description, for example, after a sufficiently long predetermined time has passed since the cooling operation stopped state, for example, between the gas-side stop valve 9 and the flow path switching valve 3, the refrigerant Consider the case where a leak occurred.

  Here, the sufficiently long predetermined time after the stop means a sufficiently long time necessary for the temperature distribution of the refrigerant in the pipe to be uniform at the equilibrium value regardless of the place of the pipe. That is, it also means the time required for the temperature of the pipe to reach a temperature that generally corresponds to the temperature of the environment in which the pipe is placed. Further, regarding the distribution relating to the position of the refrigerant, in order to make the explanation easy to understand, the case where the distribution state is uniform regardless of the place in a sufficiently long time will be described.

  Incidentally, in this embodiment, in order to apply the determination of the leakage section immediately after the cooling operation is stopped, for example, the following correction calculation may be performed. That is, a correction value is calculated for each of the refrigerant temperature detection means 51 to 53 so that the temperature value at the refrigerant leakage start time measured by the refrigerant temperature detection means 51 to 53 matches a predetermined value, and thereafter the same value is obtained. For the values measured by the refrigerant temperature detecting means 51 to 53, the same correction value as the initial correction value is added every time.

  Return to explanation. In general, when pipes are broken at joints or bends in some pipes due to aging or external force of the pipes, and the refrigerant leaks, the pressure in the pipes around the damaged part decreases, and the refrigerant expands under reduced pressure, causing the temperature to drop. .

  In addition, the refrigerant in the pipe flows toward the damaged portion, and pressure loss occurs in a portion where the flow path cross-sectional area and the bending change rapidly, and a temperature difference occurs between upstream and downstream of the flow. Here, upstream and downstream mean upstream and downstream viewed from the refrigerant flow toward the damaged part, and are different from the direction of the refrigerant flow during the cooling and heating operation.

  Continue further explanation. For example, it is assumed that the pipe is damaged at the joint or bent portion of the pipe from the gas side stop valve 9 to the flow path switching valve 3, and the refrigerant leaks. At this time, the refrigerant is ejected from the leaked portion and expanded under reduced pressure, and the temperature decreases. Further, the refrigerant remaining in the pipe flows toward the leaked portion.

  That is, for example, in the gas-side stop valve 9 corresponding to the element closest to the upstream side when viewed from the leakage location, there is a place where the flow path cross-sectional area and the bending change suddenly due to the internal structure of the valve, so that there is a pressure loss in the refrigerant flow. The pressure of the flow path switching valve 3 on the downstream side that is generated and close to the leakage point is lower.

  Here, since the saturated vapor pressure and temperature of the refrigerant are proportional to each other, the temperature becomes lower as the pressure decreases on the downstream side where the pressure is lower than the upstream side of the gas side stop valve 9, in other words, on the leakage site side.

  In other words, the temperature becomes the lowest immediately near the leakage point of the refrigerant, gradually goes away from the leakage point, and as the distance increases, the more the element having pressure loss is straddled, the lower the temperature decreases.

  In the same way, also on the upstream and downstream sides of the flow path switching valve 3 having pressure loss, the downstream side closer to the leak point, that is, the side where the gas side stop valve 9 is located is upstream, that is, the side where the compressor 2 is located. The pressure becomes lower than that, and the temperature decreases. Note that the liquid-side stop valve 8 and the gas-side stop valve 9 are always fully open as described above.

  C-1 of FIG. 2 shows a graph of the time change of the temperature detected by the refrigerant temperature detecting means 51, 52, 53 at this time. FIG. 2 is a graph showing the change over time of the temperature in the refrigerant temperature detecting means when refrigerant leakage occurs on the outdoor side for each leakage section. Note that the temperatures detected by the refrigerant temperature detecting means 51, 52, and 53 are denoted as T51, T52, and T53, respectively.

  When refrigerant leakage occurs in the state where the temperature detected by the refrigerant temperature detecting means 51 to 53 reaches an equilibrium state (that is, T51 = T52 = T53) after stopping in the cooling operation, the decompression expansion of the refrigerant jetted out of the pipe As a result of the pressure drop of the refrigerant in the pipe, the refrigerant temperature of the refrigerant in the pipe decreases. That is, T51, T52, and T53 detected by the refrigerant temperature detecting means 51, 52, and 53 all decrease.

  As time elapses, the pressure drop caused by the refrigerant jet from the leaked part and the pressure loss generated in the upstream and downstream of each element (with pressure loss) with the refrigerant flow toward the leaked part, Together, a pressure difference is created.

  That is, the more the elements that cause the pressure loss are passed through the path from the leakage location to the location where each of the refrigerant temperature detection means 51 to 53 is installed, the lower the temperature decrease rate. That is, the temperature is difficult to decrease.

Specifically, considering C-1 in Table 1, that is, the case where leakage occurs between the elements 9-3, the elements from the leakage location to the refrigerant temperature detecting means 51 are as shown in FIG. The number of elements is one by only the flow path switching valve 3. If the flow path switching valve 3 is stopped at the cooling operation position, the S tank 20 is also present in addition to the flow path switching valve 3 between the leakage point and the refrigerant temperature detection means 51. As described above, since no pressure loss occurs in the S tank 20, the number of elements is only one of the flow path switching valves 3. On the other hand, the elements from the leak location to the refrigerant temperature detecting means 52 are, for example, the gas side stop valve 9, the second heat exchanger 6, the liquid side stop valve 8, and the expansion valve 5, and the number of elements is four. The number of elements from the leak location to the refrigerant temperature detecting means 53 is only the gas side stop valve 9 and the number of elements is one. Therefore, the temperature tendency is T53 = T51 <T52 (see also Table 1).
Incidentally, there is one other method for counting the number of elements from the leakage point to the refrigerant temperature detecting means 52 in addition to the above. In other words, the flow path switching valve 3, the S tank 20, the compressor 2, the flow path switching valve 3, and the first heat exchanger 4 are counted clockwise from the leakage point. In this counting method, there is no pressure loss in the S tank 20 as described above, so the number of elements is 4 in this case as well. In any case, the number of elements to the leakage location and the refrigerant temperature detection means 52 is larger than the number of elements to the leakage location and the refrigerant temperature detection means 51 and the number of elements to the leakage location and the refrigerant temperature detection means 53. There are more. In addition, since a refrigerant | coolant flows a lot in the direction with few pressure losses, the flow of the refrigerant | coolant in the position of the refrigerant | coolant temperature detection means 52 turns into a flow toward a direction with few pressure losses.

  In any case, when the detected temperature is T53 = T51 <T52, the same temperature relationship is obtained regardless of where the refrigerant leaks from the gas side stop valve 9 to the flow path switching valve 3. Conceivable. Therefore, when T53 = T51 <T52, only the leakage of the gas side stop valve 9, the flow path switching valve 3, and the piping part connecting the two is intensively investigated, and emergency measures such as repair are not taken. That's fine. Note that the equal sign may include a case of complete match and a case of approximately match.

  When a sufficiently long time has elapsed from the leakage start time, all the refrigerant remaining in the pipe is vaporized. For this reason, at the leakage end time (t → ∞), the temperature approaches the equilibrium state again (T51 = T52 = T53).

  Therefore, if the temperature reaches an equilibrium state again at the leakage end time (t → ∞) in this way, there is no difference in the temperatures T51 to T53 of the refrigerant temperature detection means 51 to 53, so the leakage section is specified. That is, it becomes difficult to narrow down the leaked portion.

  Therefore, it is desirable to perform the narrowing determination (details will be described later in FIG. 5) of the leakage section of the present invention before the leakage end time (t → ∞).

  By narrowing down the leakage section in this way, the recovery work after refrigerant leakage can be performed overwhelmingly and quickly.

  Next, similarly, C-2 in Table 1, that is, a case where refrigerant leakage occurs between the flow path switching valve 3 and the inlet of the compressor 2 will be described.

  In this case, since there is no element straddling from the leak location to the refrigerant temperature detecting means 51, the number of elements is 0 (zero). The elements from the leak location to the refrigerant temperature detecting means 52 are the compressor 2, the flow path switching valve 3, and the first heat exchanger 4, and the number of elements is three. The elements from the leak location to the refrigerant temperature detecting means 53 are the flow path switching valve 3 and the gas side stop valve 9, and the number of elements is two. Therefore, the temperature tends to be T51 <T53 <T52 (see also graph C-2 in FIG. 2).

  Similarly, C-3 in Table 1, that is, a case where refrigerant leakage occurs between the outlet of the compressor 2 and the flow path switching valve 3 will be described.

  In this case, since there is no element straddling from the leak location to the refrigerant temperature detecting means 51, the number of elements is 0 (zero). The elements from the leakage location to the refrigerant temperature detecting means 52 are the flow path switching valve 3 and the first heat exchanger 4 and the number of elements is two. The elements from the leak location to the refrigerant temperature detecting means 53 are the compressor 2, the flow path switching valve 3, the gas side stop valve 9, and the number of elements is three. Therefore, the temperature tends to be T51 <T52 <T53 (see also graph C-3 in FIG. 2).

  Similarly, C-4 in Table 1, that is, a case where refrigerant leakage occurs between the flow path switching valve 3 and the first heat exchanger 4 will be described.

  In this case, the only elements from the leakage location to the refrigerant temperature detecting means 51 are the flow path switching valve 3 and the number of elements is one. The only elements from the leak location to the refrigerant temperature detecting means 52 are the first heat exchanger 4 and the number of elements is one. The elements from the leak location to the refrigerant temperature detection means 53 are, for example, the first heat exchanger 4, the expansion valve 5, the liquid side stop valve 8, and the second heat exchanger 6, and the number of elements is four. Therefore, the temperature tendency is T52 = T51 <T53 (see also graph C-4 in FIG. 2).

  Similarly, C-5 in Table 1, that is, a case where refrigerant leakage occurs between the first heat exchanger 4 and the expansion valve 5 will be described.

  In this case, the elements from the leak location to the refrigerant temperature detecting means 51 are the first heat exchanger 4 and the flow path switching valve 3, and the number of elements is two. The number of elements is 0 (zero) because there is no element straddling from the leak location to the refrigerant temperature detecting means 52. The elements from the leak location to the refrigerant temperature detecting means 53 are the expansion valve 5, the liquid side stop valve 8, and the second heat exchanger 6, and the number of elements is three. Therefore, the temperature tends to be T52 <T51 <T53 (see also graph C-5 in FIG. 2).

  Similarly, C-6 in Table 1, that is, a case where refrigerant leakage occurs between the expansion valve 5 and the liquid side stop valve 8 will be described.

  In this case, the elements from the leak location to the refrigerant temperature detecting means 51 are, for example, the expansion valve 5, the first heat exchanger 4, and the flow path switching valve 3, and the number of elements is three. The only elements from the leak location to the refrigerant temperature detecting means 52 are the expansion valve 5 and the number of elements is one. The elements from the leak location to the refrigerant temperature detecting means 53 are the liquid side stop valve 8 and the second heat exchanger 6 and the number of elements is two. Therefore, the temperature tends to be T52 <T53 <T51 (see also graph C-6 in FIG. 2).

  The above C-1 to C-6 are all cases where refrigerant leakage occurs on the outdoor side. Next, with reference to Table 1 and FIG. 3, C-7 and C-8 will be described for the case where refrigerant leakage occurs indoors. FIG. 3 is a graph showing the change over time of the temperature in the refrigerant temperature detection means when refrigerant leakage occurs indoors for each leakage section.

  First, C-7 in Table 1, that is, a case where refrigerant leakage occurs between the liquid side stop valve 8 and the second heat exchanger 6 will be described.

  In this case, the elements from the leak location to the refrigerant temperature detecting means 51 are, for example, the second heat exchanger 6, the gas side stop valve 9, and the flow path switching valve 3, and the number of elements is three. The elements from the leak location to the refrigerant temperature detecting means 52 are the liquid side stop valve 8 and the expansion valve 5, and the number of elements is two. The number of elements from the leakage location to the refrigerant temperature detecting means 53 is only the second heat exchanger 6 and the number of elements is one. Therefore, the temperature tends to be T53 <T52 <T51 (see also graph C-7 in FIG. 3).

  Finally, C-8 in Table 1, that is, a case where refrigerant leakage occurs between the second heat exchanger 6 and the gas side stop valve 9 will be described.

  In this case, the elements from the leakage location to the refrigerant temperature detecting means 51 are the gas side stop valve 9 and the flow path switching valve 3, and the number of elements is two. The elements from the leak location to the refrigerant temperature detecting means 52 are, for example, the second heat exchanger 6, the liquid side stop valve 8, and the expansion valve 5, and the number of elements is three. The number of elements is 0 (zero) because there is no element straddling from the leaking point to the refrigerant temperature detecting means 53. Therefore, the temperature tends to be T53 <T51 <T52 (see also graph C-8 in FIG. 3).

  As described above, it can be seen that there is a one-to-one correspondence between the leakage section and the magnitude relationship between the measured values T51 to T53 of the three refrigerant temperature detecting means 51 to 53. Therefore, by comparing the detected temperature values and deriving the temperature relational expression, it is possible to determine the leakage section, that is, to narrow down the specific leakage section in the refrigerant flow path 10.

  However, for example, in the case where the determination condition includes that a certain temperature is equal to a certain temperature as shown in C-1 and C-4, a case where the measured values are strictly matched is rarely obtained, There is a possibility that misjudgments will increase. In particular, when comparing the temperatures of the refrigerant temperature detection means installed in a place where there is a temperature difference between indoors and outdoors, for example, when comparing T53 on the indoor side and T51 on the outdoor side, misjudgment increases. there is a possibility.

  Therefore, in such a case, for example, when the difference between the two is less than a predetermined value, the determination may be made by performing appropriate corrections such as assuming that they match.

  Next, with reference to FIG. 4, the block diagram of the control mechanism regarding the refrigerant | coolant leak determination and warning of the air conditioner which concerns on 1st Embodiment is demonstrated.

FIG. 4 is a configuration diagram of a control mechanism related to refrigerant leakage detection in the air conditioner according to the first embodiment.
In the present embodiment, the control device 50 includes a leak detection unit 60 and a leak alarm unit 70.

  The leak detection unit 60 receives detection signals T51 to T53 related to temperature from the refrigerant temperature detection means 51 to 53.

  That is, when viewed from the control device 50, the refrigerant temperature detection means 51 to 53 corresponding to the input side constitute a temperature detection means.

  At this time, if the leak detection unit 60 analyzes the input signal, that is, T51, T52, T53, and determines that the refrigerant is leaking, it determines the magnitude relationship between T51, T52, T53, and leaks. A flow for determining a section is executed (details will be described later in FIG. 5).

  Further, when the leakage detection unit 60 detects refrigerant leakage by the leakage detection unit 60, for example, the terminal device 81 of the maintenance management service center 80 and the mobile terminal device 91 of the user at the outside location 90 via the wired / wireless network NWK. The refrigerant leakage information is reported / notified to the portable terminal device 101 of a predetermined registration destination 100 such as a relative.

  In addition, the information notified at this time may notify only the fact of a refrigerant | coolant leak, and may contain the leak area information calculated and calculated by the leak detection part 60 simultaneously.

  In addition, the leakage warning unit 70 uses the siren or buzzer 110 provided in the indoor unit 1b to notify the occurrence of an abnormality due to sound, and causes the operation lamp 120 to flash with a predetermined light emission pattern or to generate an emergency situation. It is also possible to make known the occurrence of abnormalities due to light, such as determining a predetermined color to be used in advance and switching to that color.

  That is, the maintenance management service center 80, the user 90 at the outside, the predetermined registration destination 100, the sirenzer 110, and the operation lamp 120, which are on the output side when viewed from the control device 50, constitute the refrigerant leakage warning means. doing.

(Modification)
As a modification of FIG. 4, in addition to the refrigerant leakage warning means on the output side of the control device 50, the flammable concentration of the leaked refrigerant is further reduced by using the fans 7a and 7b attached to the known refrigeration cycle. You may make it provide the structure which controls these as a means.

  This control is performed for the purpose of diffusing so that the leaked refrigerant does not accumulate and reach the flammable concentration. For example, depending on whether the leak detection unit 60 determines whether the leak section is the outdoor side or the indoor side, the fan 7a is operated if the outdoor side and the fan 7b is used if the outdoor side, and the fan on the leaked side is turned on to operate. Therefore, it can be configured to diffuse.

Next, referring to the flowchart of FIG. 5, a control flow for determining the presence / absence of leakage and a leakage section when there is a leakage of the air conditioner 1 according to the present embodiment will be described (as appropriate) (See also temperature relationship in Table 1).
Hereinafter, for convenience of explanation, the determination relating to “the presence / absence of leakage or the leakage section when there is leakage” is simply referred to as “leakage determination”.

  For example, when the operation is stopped from the cooling operation, the compressor 2 is stopped, and the refrigerant leakage monitoring mode is set (step S100). At this time, the flow path switching valve 3 is in a position for performing the cooling operation, and the expansion valve 5 is fully opened or at the opening degree immediately before the operation.

  Next, it progresses to step S101 and the leak detection part 60 of the control apparatus 50 determines whether T52-T53 = 0 is materialized. This is because there is no example in which T52-T53 is equal to 0 in C-1 to C-8, which covers all leakage sections, and this conditional expression is intended to be used as a Merckmar for leakage determination. is there.

  In the case of Yes in step S101, the leakage detection unit 60 determines in step S102 that there is no leakage in all sections, and proceeds to step S103.

  In step S103, the leak detection unit 60 waits for a predetermined time T and returns to the leak determination step in step S101 again. At this time, the predetermined time T may be measured by a timer (not shown) built in the leak detection unit 60 or connected to the outside. Alternatively, a predetermined time T stored in advance may be loaded from a storage device (not shown), or a predetermined time T selected by the user may be received from an input device such as a remote controller (not shown).

  In this way, the leakage detection unit 60 is configured to constantly monitor the leakage of the refrigerant at a predetermined time T interval.

  If No in step S101, that is, if T52 ≠ T53, the leak detection unit 60 determines that there is a leaking point in any of the sections C-1 to C-8, and the process proceeds to step S104. move on. Step S104 and subsequent steps are a leakage index step for specifying a leakage section.

In step S104, the leak detection unit 60 determines whether or not the minimum value of T51, T52, and T53 is T53 and T53 ≠ T51 is satisfied.
This is a step for narrowing down whether the leakage location is the indoor side, that is, C-7 or C-8, or the outdoor side, that is, C-1 to C-6.

  If the answer is Yes in step S104, the leak detection unit 60 determines that the leak is in the room and proceeds to step S105.

  In step S105, the leakage detection unit 60 determines whether T52 <T51 is satisfied. This is a step for distinguishing between C-7 and C-8.

If Yes in step S105, T53 <T52 <T51, so in this case it is determined that C-7 and this flow ends. That is, it is specified that the leakage section is between the liquid side stop valve 8 and the second heat exchanger 6.
On the other hand, in the case of No in step S105, T53 <T51 <T52, so in this case, it is determined that C-8 and this flow ends. That is, it is specified that the leakage section is between the second heat exchanger 6 and the gas side stop valve 9.

  Next, in the case of No in step S104, the leakage detection unit 60 determines that the leakage section is the outdoor side, that is, any one of C-1 to C-6, and proceeds to step S106.

  In step S106, the leak detection unit 60 determines whether the minimum value of T51, T52, and T53 is T51. This step is a step for determining whether the leakage section is C-1 to C-3 or C-4 to C-6.

  If it is determined Yes in step S106, it corresponds to the case where leakage occurs in C-1 to C-3. For this reason, the leak detection unit 60 determines whether T51 = T53 is established in step S107, and determines whether it is C-1 or not.

  In the case of Yes in step S107, since T51 = T53 <T52, it is determined that C-1 and this flow ends. That is, it is specified that the leakage section is from the gas side stop valve 9 to the flow path switching valve 3.

  In the case of No in step S107, the process proceeds to step S108, and the leakage detection unit 60 determines whether T53 <T52 is satisfied. This is a step for determining whether the leakage section is C-2 or C-3.

In the case of Yes in step S108, since T51 <T53 <T52, it is determined that C-2 and this flow ends. That is, it is specified that the leakage section is between the flow path switching valve 3 and the inlet of the compressor 2.
On the other hand, in the case of No in step S108, since T51 <T52 <T53, it is determined that C-3 and this flow ends. That is, it is specified that the leakage section is from the outlet of the compressor 2 to the flow path switching valve 3.

  If it is determined No in step S106, the minimum value among T51, T52, and T53 is T52, and this is a case where leakage occurs at C-4 to C-6. For this reason, the leak detection unit 60 determines whether T52 = T51 is established in step S109, and first determines whether it is C-4.

  In the case of Yes in step S109, since T51 = T52 <T53, it is determined that C-4, and this flow ends. That is, it is specified that the leakage section is between the flow path switching valve 3 and the first heat exchanger 4.

  In the case of No in step S109, the process proceeds to step S110, and the leakage detection unit 60 determines whether T51 <T53 is satisfied. This is a step for determining whether the leakage section is C-5 or C-6.

In the case of Yes in step S110, since T52 <T51 <T53, it is determined that C-5 and this flow ends. That is, it is specified that the leakage section is between the first heat exchanger 4 and the expansion valve 5.
On the other hand, in the case of No in step S110, it is determined as C-6 by the erasing method, and this flow ends. That is, it is specified that the leakage section is between the expansion valve 5 and the liquid side stop valve 8.

  In this way, in the control device, the section where the refrigerant is leaking is from the section where one of the two temperature sensors having a low temperature among the at least three temperature sensors belongs. It is determined that leakage occurs in any of the sections (sections including both end sections) up to the section to which the other temperature sensor belongs.

  In addition, you may make it determine the waiting time of the predetermined time T in step S103 with the combustible lower limit density | concentration which is a physical-property value of the refrigerant | coolant to seal. Here, the combustible lower limit concentration of the refrigerant is the lower limit value of the combustible concentration.

  For example, when the flammable lower limit concentration is small, such as R290 (flammable lower limit concentration 2.2%) or R600a (flammable lower limit concentration 1.8%), the space after the jetted refrigerant leaks outside, and the flammable concentration space Therefore, the detection timing is shortened, and the control flow for determining and reporting the leakage section is executed before the combustible concentration is reached.

  In addition, when the flammable lower limit concentration is large, such as R32 (flammable lower limit concentration 13.8%) or R1234yf (flammable lower limit concentration 12.3%), the refrigerant after ejection leaks out of the apparatus, resulting in a flammable concentration space. Therefore, it is more preferable to lengthen the detection timing and optimize so that the power consumption by sensing during execution of the leakage monitoring flow is minimized.

  By doing in this way, the air conditioner 1 of this invention can be used regardless of the value of the combustible lower limit density | concentration of a refrigerant | coolant.

  As described above, it is possible to provide an air conditioner that can detect a leakage section without using a dedicated gas sensor when the operation is stopped.

(Action / Effect)
The actions and effects of this embodiment are summarized as follows.
When the present invention is applied, the refrigeration cycle is divided into a total of 8 sections from the viewpoint of pressure loss, and a temperature sensor that is a refrigerant temperature detection means does not provide temperature sensors in all 8 sections, but only at least 3 locations are sensed. Thus, it is possible to specify in which section the refrigerant leakage occurs.

  As a result, the system configuration can be simplified and the cost can be reduced.

  Further, the refrigerant detection means 51 to 53, that is, the temperature sensor is used as the leakage detection sensor instead of an expensive gas sensor that is desired to be regularly maintained at intervals of about one year, thereby reducing manufacturing costs and maintenance costs. It can be further reduced.

  Further, when refrigerant leakage is detected, the determination of the leakage section is automatically started before reaching the leakage end time, and information including the determination result can be alerted and publicized as leakage information. Compared to the device, the recovery work can be performed much faster.

  Moreover, since the frequency of refrigerant leakage sensing can be set so as to decrease as the value of the flammable lower limit concentration of the refrigerant used increases, power consumption can be reduced.

  Moreover, the safety | security at the time of a refrigerant | coolant leak is achieved by comprising in this way. For this reason, the refrigerant | coolant to be used may use single refrigerant | coolants, such as R32 and R1234yf, or the mixed refrigerant | coolant which has them as a main component, for example. Moreover, you may use single refrigerant | coolants, such as R290 and R600a, or the mixed refrigerant | coolant which has them as a main component.

(Second Embodiment)
In the first embodiment, temperature sensors are used for the refrigerant temperature detecting means 51 to 53, and the values T 51 to T 53 measured respectively are input to the leakage detection unit 60 of the control device 50.

On the other hand, in this embodiment, instead of the refrigerant temperature detecting means, a pressure sensor (not shown because the configuration is the same as that in FIGS. 1 and 4) is provided as a leak detection sensor inside the pipe at the same position as the refrigerant temperature detecting means. It has a configuration equipped with.
The other points are the same as in the first embodiment. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

In this case, when the refrigerant leaks, the pressure in the pipe rapidly decreases around the leaked portion, so that this pressure is directly sensed.
Since the mechanism in which the pressure is less likely to decrease as the plurality of lossy elements are straddled from the leak location to the position of each pressure sensor that is the leak detection sensor is the same as in the first embodiment, detailed description thereof is omitted.

Even if comprised in this way, there can exist an effect similar to 1st Embodiment. In addition to this, for example, the air temperature detecting means 54 may be provided inside the outdoor unit 1a, and the air temperature detecting means 55 may be provided inside the indoor unit 1b (both not shown).
In this case, the same temperature sensor as the refrigerant temperature detecting means 51 to 53 can be used as the leakage detection sensor.

  In this case, the air temperature detecting means 54 may detect the air temperature in the vicinity of the first heat exchanger 4, for example. Moreover, you may make it the air temperature detection means 55 detect the air temperature of the 2nd heat exchanger 6 vicinity, for example.

  In this manner, for example, in step S104 (see FIG. 5) for determining whether the leakage location is the indoor side or the outdoor side, it is possible to perform a double check to determine whether the temperature drop of the air accompanying the ejection of the leaked refrigerant has been detected. It can be set as the structure which prevents a misjudgment so that it may confirm.

  Further, when comparing the temperatures T51 to T53 of the refrigerant temperature detecting means 51 to 53, referring to the air temperatures inside the outdoor unit 1a and the indoor unit 1b detected by the air temperature detecting means 54 and 55, You may make it compare after correcting the influence by a temperature difference. In this way, erroneous determination can be further reduced.

  Furthermore, it is needless to say that if there is no budget constraint, a configuration in which four or more, that is, a large number of refrigerant temperature detection means are provided.

  This is because, strictly speaking, in all elements in which pressure loss occurs, a temperature difference occurs upstream and downstream without exception. For this reason, if the temperature is detected before and after the comparison, the leakage location can be estimated in more detail.

  Examples of such installation location candidates include the inlet and outlet of the compressor 2, the upstream and downstream of the expansion valve 5, and the upstream and downstream of the flow path switching valve 3.

  The above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the described configurations.

  For example, in FIG. 4, the control device 50 has been described with the configuration including the leak detection unit 60 and the leak alarm unit 70, but these are configured separately and connected to each other by a communication line (not shown). May be.

  That is, the control lines and information lines indicate what is considered necessary for the explanation, and not all control lines and information lines are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  In addition, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and a part or all of the configuration of another embodiment can be added to the configuration of one embodiment. It is.

  Specifically, for example, in the first embodiment, in addition to the refrigerant temperature detection means, the air temperature detection means described in the second embodiment may be used in combination.

  In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Specifically, although both the first embodiment and the second embodiment have been described in the stopped state from the cooling operation, the present invention can be applied as it is even in the stopped state from the heating operation.

  This is because the heating operation is a configuration in which the direction of the refrigerant flow as shown in FIG. 1 is the direction of the broken line arrow, and the connection of the flow path switching valve 3 is switched to the path indicated by the broken line. That is, because the arrangement order of the elements shown in Table 1 is not changed due to the difference in cooling and heating, the number of elements from the leakage location to each refrigerant temperature detection means does not change.

1 Air conditioner (cooling / heating equipment)
DESCRIPTION OF SYMBOLS 1a Outdoor unit 1b Indoor unit 2 Compressor 3 Flow path switching valve 4 1st heat exchanger (condenser)
5 Expansion valve 6 Second heat exchanger (evaporator)
7a, 7b Blower 8, 9 Stop valve 10 Refrigerant circuit 20 Suction tank (S tank)
50 Control device 51, 52, 53, 54, 55 Temperature detection means (sensor)
60 Leakage detector (control device)
70 Leakage alarm section (alarm means)
80 maintenance management service center 81 terminal device 90 user who goes out 91 mobile terminal device 100 predetermined registration destination 101 mobile terminal device 110 silencer 120 operation lamp NWK network C-1, C-2, C-3, C-4, C-5, C-6, C-7, C-8 Section T Predetermined time t Elapsed time

Claims (6)

A refrigeration cycle comprising a compressor, a condenser, an expansion valve, an evaporator;
At least three or more sensors provided at spaced positions on the refrigeration cycle;
A control device for determining a section in which refrigerant leaks based on a value input from the sensor;
A cooling / heating apparatus comprising: The cooling / heating apparatus is an air conditioner,
The sensor is a temperature sensor;
The cooling / heating apparatus according to claim 1, wherein the control device performs the determination by paying attention to a temperature level. The cooling / heating apparatus according to claim 1 or 2, wherein the section is a section delimited by elements that generate pressure loss. When the refrigerant leaks during the operation of the refrigeration cycle, the control device is configured such that the interval in which the refrigerant leaks includes at least two of the temperature sensors having a low temperature among the three or more temperature sensors. 3. The cooling according to claim 2, wherein it is determined that the time is between a section where one of the two temperature sensors having a low temperature is installed and a section where the other is installed. Thermal equipment. A refrigeration cycle comprising a compressor, a condenser, an expansion valve, an evaporator;
At least three or more temperature sensors provided at respective spaced positions on the refrigeration cycle;
An alarm means for notifying information relating to a section where the refrigerant is leaked based on a value from the temperature sensor when the refrigerant leaks during operation of the refrigeration cycle;
A cooling / heating apparatus comprising: The said refrigerant | coolant is R32, R1234yf, R290, R600a which are single refrigerant | coolants, or the mixed refrigerant | coolant which has these as a main component, The cooling / heating apparatus of any one of Claims 1-5 characterized by the above-mentioned. .

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