JP3920671B2 - Air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner including an engine cooling device that cools an engine that drives a compressor.
[0002]
[Prior art]
2. Description of the Related Art In general, an air conditioner including an engine cooling device is known in which a compressor mounted in an outdoor unit is driven by an engine and the cooling water of the engine is cooled by circulating it through a radiator with a cooling water circulation pump.
[0003]
Since this type of engine cooling device is configured by connecting water pipes, there is a risk of leakage of cooling water from each connecting portion.
[0004]
[Problems to be solved by the invention]
However, conventionally, there is no means for efficiently detecting this cooling water leakage, and there has been a problem that the cooling water temperature rises abnormally due to the lack of cooling water.
[0005]
Therefore, an object of the present invention is to provide an air conditioner that can solve the above-described problems of the prior art and can efficiently detect a coolant leak in the engine cooling device.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is an air conditioner provided with an engine cooling device in which a compressor mounted in an outdoor unit is driven by an engine and the cooling water of the engine is cooled by circulating it through a radiator with a cooling water circulation pump. And a detecting means for detecting the driving current of the cooling water circulation pump and a determining means for determining the occurrence of air biting of the cooling water circulation pump based on the detected value , wherein the determining means is a detected value of the driving current. As a reference value to be compared with the reference value, there are two reference values, a lower limit reference value and an upper limit reference value, and when the detection value of the first drive current is equal to or lower than the lower limit reference value, the determination means immediately determines that the air is engaged. If it exceeds the upper limit reference value, it is determined as a false detection; otherwise, the drive current value is counted multiple times to obtain an average value, and if this average value exceeds a predetermined air bite determination value, And judging the bite.
[0009]
The invention according to claim 2 is the one according to claim 1 , wherein the number of times of air biting is counted, and when this count reaches a predetermined number of times within a predetermined time, it is finally determined that air biting has occurred. It is characterized by doing.
[0010]
According to a third aspect of the present invention, in the first or second aspect of the present invention, when the occurrence of air biting of the cooling water circulation pump is detected, a cooling water shortage message is output.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a circuit diagram showing a refrigerant circuit and the like in an embodiment of an air conditioner according to the present invention.
[0013]
As shown in FIG. 1, a heat pump type air conditioner 10 as a refrigeration apparatus includes an outdoor unit 11, for example, a plurality of (for example, two) indoor units 12A and 12B and a control unit 13, and the outdoor unit 11 outdoor refrigerant pipes 14 and indoor refrigerant pipes 15A and 15B of the indoor units 12A and 12B are connected to each other.
[0014]
The outdoor unit 11 is installed outside, a compressor 16 is disposed in the outdoor refrigerant pipe 14, an accumulator 17 is disposed on the suction side of the compressor 16, and a four-way valve 18 is disposed on the discharge side. An outdoor heat exchanger 19, an outdoor expansion valve 24, and a dry core 25 are sequentially arranged on the four-way valve 18 side. An outdoor fan 20 that sucks air from the outdoor heat exchanger 19 side is disposed adjacent to the outdoor heat exchanger 19. The compressor 16 is connected to the gas engine 30 via the flexible coupling 27 and the like, and is driven by the gas engine 30. Further, a bypass pipe 26 is provided to bypass the outdoor expansion valve 24.
[0015]
On the other hand, the indoor units 12A and 12B are installed indoors, and indoor heat exchangers 21A and 21B are provided in the indoor refrigerant pipes 15A and 15B, respectively. Indoor expansion valves 22A and 22B are arranged in the vicinity of 21A and 21B. The indoor heat exchangers 21A and 21B are disposed adjacent to indoor fans 23A and 23B for blowing air from the indoor heat exchangers 21A and 21B to the room.
[0016]
In addition, the code | symbol 28 in FIG. 1 shows a strainer. Reference numeral 29 denotes a safety valve that releases the refrigerant pressure on the discharge side of the compressor 16 to the suction side of the compressor 16.
[0017]
The controller 13 is installed in the outdoor unit 11 and controls the operation of the outdoor unit 11 and the indoor units 12A and 12B. Specifically, the control device 13 includes the gas engine 30 (that is, the compressor 16), the four-way valve 18, the outdoor fan 20, and the outdoor expansion valve 24 in the outdoor unit 11, and the indoor expansion valves 22A and 22B in the indoor units 12A and 12B. , And indoor fans 23A and 23B, respectively. Further, the control device 13 controls a circulation pump 47, a three-way valve 45, and the like of the engine cooling device 41 described later.
[0018]
By switching the four-way valve 18 by the control device 13, the heat pump type air conditioner 10 is set to the cooling operation or the heating operation. That is, when the control device 13 switches the four-way valve 18 to the cooling side, the refrigerant flows as indicated by solid arrows, the outdoor heat exchanger 19 becomes a condenser, and the indoor heat exchangers 21A and 21B become evaporators to perform a cooling operation. Each indoor heat exchanger 21A, 21B cools the room. Further, when the control device 13 switches the four-way valve 18 to the heating side, the refrigerant flows as indicated by broken arrows, the indoor heat exchangers 21A and 21B become condensers, and the outdoor heat exchanger 19 becomes an evaporator and heating operation is performed. It will be in a state and each indoor heat exchanger 21A, 21B will heat a room | chamber interior.
[0019]
Moreover, the control apparatus 13 controls each valve opening degree of indoor expansion valve 22A, 22B according to an air-conditioning load at the time of air_conditionaing | cooling operation. During the heating operation, the control device 13 controls the valve openings of the outdoor expansion valve 24 and the indoor expansion valves 22A and 22B according to the air conditioning load.
[0020]
On the other hand, an air-fuel mixture is supplied from an engine fuel supply device 31 to a combustion chamber (not shown) of the gas engine 30 that drives the compressor 16. In the engine fuel supply device 31, two fuel cutoff valves 33, a zero governor 34, a fuel adjustment valve 35, and an actuator 36 are sequentially disposed in a fuel supply pipe 32. The gas engine 30 is configured to be connected to the combustion chamber.
[0021]
Two fuel shut-off valves 33 are arranged in series to form a two-closed type fuel shut-off valve mechanism, and the two fuel shut-off valves 33 are interlocked to be fully closed or fully opened so that fuel gas does not leak. And communication.
[0022]
The zero governor 34 is caused by fluctuations in the primary pressure a among the primary fuel gas pressure (primary pressure a) and the secondary fuel gas pressure (secondary pressure b) before and after the zero governor 34 in the fuel supply pipe 32. Also, the secondary pressure b is adjusted to a constant predetermined pressure to stabilize the operation of the gas engine 30.
[0023]
The fuel adjustment valve 35 optimally adjusts the air-fuel ratio of the air-fuel mixture generated by introducing air from the upstream side of the actuator 36. Further, the actuator 36 controls the rotational speed of the gas engine 30 by adjusting the supply amount of the air-fuel mixture supplied to the combustion chamber of the gas engine 30.
[0024]
An engine oil supply device 37 is connected to the gas engine 30. The engine oil supply device 37 is provided with an oil shutoff valve 39, an oil supply pump 40, and the like in an oil supply pipe 38, and appropriately supplies engine oil to the gas engine 30.
[0025]
The control of the gas engine 30 by the control device 13 is specifically performed by the fuel cutoff valve 33 of the engine fuel supply device 31, the zero governor 34, the fuel adjustment valve 35 and the actuator 36, and the oil cutoff valve 39 of the engine oil supply device 37. The control device 13 controls the oil supply pump 40.
[0026]
The gas engine 30 is cooled by an engine cooling medium (for example, engine cooling water) circulating in the engine cooling device 41 installed in the outdoor unit 11. The engine cooling device 41 has a substantially closed loop shape in which one end is connected to an exhaust gas heat exchanger (not shown) attached to the gas engine 30 via the gas engine 30 and the other end is directly connected to the exhaust gas heat exchanger. The cooling water pipe 42 includes a wax three-way valve 43, a three-way valve 45, a plate heat exchanger 44 as a radiator, a radiator 46, and a circulation pump 47. The plate heat exchanger 44 and the radiator (heat radiator) 46 are arranged in parallel to the cooling water pipe 42 that is the circulation path of the engine cooling water.
[0027]
The circulation pump 47 boosts the engine cooling water during operation and circulates the engine cooling water in the cooling water pipe 42.
[0028]
The wax three-way valve 43 is for quickly warming up the gas engine 30. The wax three-way valve 43 has an inlet side port 43A on the exhaust gas heat exchanger side attached to the gas engine 30 in the cooling water pipe 42 and a low temperature side port 43B on the suction side of the circulation pump 47 in the cooling water pipe 42. The side ports 43C are connected to the three-way valve 45 side in the cooling water pipe 42, respectively.
[0029]
In the three-way valve 45, the port 45A on the inlet side of the three-way valve 45 is connected to the wax three-way valve 43 side in the cooling water pipe 42, and the first port 45B of the three-way valve 45 is plate type heat exchange in the cooling water pipe 42. The second port 45C of the three-way valve 45 is connected to the radiator 46 side in the cooling water pipe 42.
[0030]
The three-way valve 45 is an electromagnetic or electric proportional three-way valve. Thereby, engine cooling water can be alternatively led to the plate heat exchanger 44 side or the radiator 46 side simply by switching the three-way valve 45.
[0031]
In this three-way valve 45, the engine cooling water flowing in from the wax three-way valve 43 passes through the first port 45B of the three-way valve 45 during the heating operation and goes to the plate heat exchanger 44 side, and during the cooling operation, the three-way valve. It is switched by the control device 13 so as to flow to the radiator 46 side through the 45 second port 45C.
[0032]
The plate heat exchanger 44 is installed on the refrigerant suction side of the compressor 16, and flows through the four-way valve 18 to the refrigerant suction port 16 </ b> A of the compressor 16, and engine cooling water flowing in from the three-way valve 45. The refrigerant is heated by the exhaust heat of the gas engine 30 to raise the temperature (pressure increase) and cool the engine cooling water. The radiator 46 discharges heat of the engine coolant flowing into the radiator 46 and is disposed adjacent to the outdoor heat exchanger 19. Therefore, heat radiation is promoted by the outdoor fan 20. The radiator 46 is installed on the leeward side of the outdoor heat exchanger 19.
[0033]
A cooling water pipe 42 between the gas engine 30 and the wax three-way valve 43 on the outlet side of the engine cooling water of the gas engine 30 is provided with a temperature sensor 50 for detecting the temperature of the engine cooling water. A signal indicating the temperature detected by the temperature sensor 50 is sent to the control device 13.
[0034]
The engine cooling water flows into the exhaust gas heat exchanger of the gas engine 30 from the discharge side of the circulation pump 47, collects exhaust heat (heat of exhaust gas) of the gas engine 30, and then flows through the gas engine 30 to recover the gas. The engine 30 is cooled and heated. For example, when the engine coolant flows from the discharge side of the circulation pump 47 into the exhaust gas heat exchanger of the gas engine 30 at about 70 ° C., the exhaust gas (heat of exhaust gas) of the gas engine 30 is recovered and then the gas engine is recovered. The gas engine 30 is cooled by flowing through the interior 30 and heated to about 80 ° C.
[0035]
The engine coolant flowing into the wax three-way valve 43 from the gas engine 30 is at a lower temperature side of the wax three-way valve 43 than the flow rate flowing from the high temperature side port 43C of the wax three-way valve 43 to the three-way valve 45 when the temperature is low (for example, 80 ° C. or lower). The flow rate returned from the port 43B to the circulation pump 47 is large, and the gas engine 30 is quickly warmed up. When the temperature is high (for example, 80 ° C. or higher), the flow rate is returned from the low temperature side port 43B of the wax three-way valve 43 to the circulation pump 47. Also, the flow rate flowing from the high temperature side port 43C of the wax three-way valve 43 to the three-way valve 45 is large.
[0036]
Next, the operation of the engine cooling device 41 during the air conditioning operation will be described.
[0037]
During the heating operation, the three-way valve 45 is switched to the plate heat exchanger 44 side by the control device 13. As a result, the engine coolant flowing from the high temperature side port 43C of the wax three-way valve 43 to the three-way valve 45 is led from the first port 45B of the three-way valve 45 to the plate heat exchanger 44 to exchange heat with the refrigerant. It is cooled (heat dissipated) and led to the exhaust gas heat exchanger of the gas engine 30 through the suction side of the circulation pump 47. Thereby, it becomes possible to control the cooling water amount optimal for the heating operation.
[0038]
During the cooling operation, the three-way valve 45 is switched to the radiator 46 side by the control device 13. Thus, the engine coolant flowing from the high temperature side port 43C of the wax three-way valve 43 to the three-way valve 45 is led from the second port 45C of the three-way valve 45 to the radiator 46 to be cooled (heat radiation), and the circulation pump 47 It is led to the exhaust gas heat exchanger of the gas engine 30 through the suction side.
[0039]
Now, in the above configuration, there is a possibility that cooling water leaks from each part of the engine cooling device 41. If this cooling water leak is left unattended, the cooling water may be insufficient, and the cooling water temperature may rise abnormally. In the worst case, the engine may be burned.
[0040]
In the present embodiment, the detection means 51 for detecting the drive current of the cooling water circulation pump 47 and the control means (determination means) 13 for determining the occurrence of air biting of the cooling water circulation pump 47 based on the detected value are provided. Is done.
[0041]
FIG. 2 shows a determination routine in the determination means 13.
[0042]
This determination means 13 has two reference values, a lower limit reference value α and an upper limit reference value β, as reference values to be compared with the detected value of the drive current of the circulation pump 47 during operation of the engine cooling device 41. First, it is determined whether the drive current value X of the circulation pump 47 detected by the detection means 51 is lower than the lower limit reference value α, higher than the upper limit reference value β, or otherwise (S1).
[0043]
If it is higher than the upper reference value β, it is returned to the start as a false detection. If it is between the upper limit reference value β and the lower limit reference value α, an average value Y (or its standard deviation) of B drive currents detected over a predetermined number of times is obtained (S2). And the drive current value X is determined (S3), and it is determined whether the difference Z exceeds the air engagement determination value γ (S4). If this difference Z exceeds the air biting determination value γ, it is determined that the air biting occurs, and this determination result is counted (S5). If this count reaches a predetermined number of times ε within a predetermined time, the final determination is made. Then, it is determined that air biting has occurred (S6).
[0044]
If it is lower than the lower limit reference value α in S1, it is immediately determined that the air is biting, S2 to S4 are skipped, and this determination result is counted (S5), and thereafter the same determination is made (S6).
[0045]
According to this configuration, even if it is determined that “air biting” once, the number of times that “air biting” is determined is counted in consideration of detection error and the like, and this count is a predetermined number of times ε within a certain time. In the case of reaching, since it is finally determined that “air biting has occurred”, almost reliable determination is possible.
[0046]
When it is determined that “air biting has occurred”, the cooling water of the engine cooling device 41 is insufficient. Therefore, when it is determined that “the air biting has occurred”, it is preferable that the determination unit 13 outputs a message indicating that the cooling water is insufficient by means such as a buzzer or a lamp display.
[0047]
In the present embodiment, it is possible to detect a cooling water leak of the engine cooling device 41 by determining “air biting”, and thus it is possible to prevent an abnormal increase in the cooling water temperature due to a lack of cooling water.
[0048]
As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this.
[0049]
【The invention's effect】
According to the present invention, it is possible to detect a cooling water leak of the engine cooling device by determining the air engagement of the cooling water circulation pump, and it is possible to prevent an abnormal increase in the cooling water temperature due to a lack of cooling water.
[Brief description of the drawings]
FIG. 1 is a circuit diagram in an embodiment of an air conditioner according to the present invention.
FIG. 2 is a diagram illustrating a determination routine in a determination unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Air conditioning apparatus 11 Outdoor unit 12A, 12B Indoor unit 13 Control apparatus (determination means)
41 Engine cooling device 47 Cooling water circulation pump 51 Detection means

Claims (3)

In an air conditioner equipped with an engine cooling device that is driven by an engine and is cooled by circulating the cooling water of the engine to a radiator with a cooling water circulation pump,
Detecting means for detecting a driving current of the cooling water circulation pump;
Determination means for determining occurrence of air biting of the cooling water circulation pump based on the detected value ,
The determination means has two reference values, a lower limit reference value and an upper limit reference value, as reference values to be compared with the detection value of the drive current, and the determination means has the first detection value of the drive current as the lower limit reference value. In the following cases, it is immediately determined that the air is biting, and if it exceeds the upper limit reference value, it is determined as false detection. Otherwise, the drive current value is counted a plurality of times to obtain an average value, and this average value is a predetermined air value. An air conditioner characterized by determining air biting when the biting determination value is exceeded . 2. The air conditioner according to claim 1, wherein the number of times of determination as air biting is counted, and when this count reaches a predetermined number of times within a predetermined time, it is finally determined that air biting has occurred. The air conditioner according to claim 1 or 2, wherein when an occurrence of air biting of the cooling water circulation pump is detected, a cooling water shortage message is output.

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