JP4030501B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner that includes a fuel shut-off valve that shuts off fuel supply to an engine while a compressor is driven by the engine.

  As an air conditioner, a gas heat pump type air conditioner in which a compressor is driven by a gas engine is known (see, for example, Patent Document 1), and fuel gas and air are transferred from the gas engine fuel supply device to the gas engine. Is supplied.

Such an engine fuel supply apparatus includes a fuel adjustment valve, and a controller configured by a microcomputer adjusts the opening of the fuel adjustment valve and changes the supply amount of the fuel gas, so that the air-fuel ratio of the air-fuel mixture is reduced. Adjust optimally.
Japanese Patent Laid-Open No. 10-339251

  By the way, the microcomputer for controlling the conventional engine fuel supply apparatus incorporates a watchdog timer in order to detect a malfunction of the microcomputer.

  This watchdog timer function is used for the purpose of detecting a program runaway state.

  Specifically, when a watchdog timer overflows, a watchdog interrupt occurs. For example, if a watchdog interrupt occurs twice in succession, it is determined that the runaway state cannot be restored by software. Then, the microcomputer is forcibly reset by hardware, and the operation is performed again.

  However, in the above configuration, there is a problem that the watchdog timer operates repeatedly after the fuel gas supply operation in some cases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an air conditioner that can detect a failure of a microcomputer that constitutes a controller, prevent repeated restart operations due to the failure of the controller, and shut off the supply of fuel gas. It is to provide.

  In order to solve the above-described problem, in an air conditioner configured to supply a fuel to an engine via a fuel cutoff valve, a compressor provided in an outdoor unit is driven by the engine. The control unit that controls the operation of the engine and the fuel cutoff valve and the activation of the air conditioner includes an operation state determination unit that determines whether or not the air conditioner can operate normally during the operation of the air conditioner, and the determination When it is determined that the device is not normally operable, a shut-off state holding unit that holds the state where the fuel supply is shut off by the fuel shut-off valve, and a restart process for the air conditioner A watchdog timer for performing a watchdog interrupt, wherein the control unit is in a state where the fuel supply to the engine is cut off by the cut-off state holding unit. After the restart process is performed, the operation state determination unit determines whether or not the device can operate normally again, and when the operation state determination unit determines that the device is not normally operable, The restart process by a watchdog interrupt is prohibited.

According to the above configuration, the operation state determination unit determines whether or not it can normally operate during operation of the air conditioner.
Thereby, the cut-off state holding unit holds the state where the fuel supply is cut off by the fuel cut-off valve when it is determined that the self-operation is not normally performed.
In addition, the watchdog timer performs a watchdog interrupt for causing the air conditioner to restart.

  The control unit determines whether or not it can operate normally again by the operation state determination unit after the restart process is performed in a state where the fuel supply to the engine is cut off by the cutoff state holding unit, and determines the operation state. If the unit determines that it cannot operate normally, the restart process by the watchdog interrupt is prohibited.

  In this case, the controlled portion may be in a state in which the fuel supply is cut off by the fuel cutoff valve when the control portion is not normally operable.

  The controlled unit may be any one of the shut-off valve, a storage unit that stores various data, and an analog sensor A / D conversion unit.

  Furthermore, the control unit includes a data storage unit that stores various data as the controlled unit, and the operation state determination unit determines whether the data stored in the data storage unit is normal. Based on this, it may be determined whether or not the device can operate normally.

  Furthermore, the data storage unit may include at least one of a register, a RAM, and a ROM.

According to the present invention, the control unit of the air conditioner configured to supply the fuel to the engine via the fuel shut-off valve is driven by the engine, and the shut-off state holding unit is provided. After the restart process is performed in a state where the fuel supply to the engine is shut off by the operation state, the operation state determination unit determines again whether or not it can operate normally, and the operation state determination unit determines that the self is normal. When it is determined that the operation is not possible, the restart process by the watchdog interrupt is prohibited, so that it is possible to maintain the state where the fuel supply is shut off by the fuel shut-off valve without repeating the restart unnecessarily. .

  Next, preferred embodiments of the present invention will be described with reference to the drawings.

  Drawing 1 is an outline lineblock diagram showing the refrigerant circuit and control system of the air harmony device of an embodiment.

  As shown in FIG. 1, a gas heat pump type air conditioner 10 as a refrigeration apparatus includes an outdoor unit 11, a plurality of (two in FIG. 1) indoor units 12 </ b> A and 12 </ b> B, and a controller 13. Moreover, the outdoor refrigerant | coolant piping 14 of the outdoor unit 11 and each indoor refrigerant | coolant piping 15A, 15B of indoor unit 12A, 12B are connected.

  The outdoor unit 11 is installed outside, and 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 of the compressor 16. 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.

  An outdoor fan 20 that blows air toward the outdoor heat exchanger 19 is disposed adjacent to the outdoor heat exchanger 19.

  On the other hand, the indoor units 12A and 12B are installed indoors. An indoor heat exchanger 21A is arranged in the indoor refrigerant pipe 15A, and an indoor expansion valve 22A is arranged in the vicinity of the indoor heat exchanger 21A in the indoor refrigerant pipe 15A. Similarly, an indoor heat exchanger 21B is provided in the indoor refrigerant pipe 15B, and an indoor expansion valve 22B is provided in the vicinity of the indoor heat exchanger 21B in the indoor refrigerant pipe 15B.

  Here, an indoor fan 23A that blows air to the indoor heat exchanger 21A is disposed adjacent to the indoor heat exchanger 21A, and an indoor fan 23B that blows air to the indoor heat exchanger 21B is disposed in the indoor heat exchanger 21B. Are arranged adjacent to each other.

  Reference numeral 28 in FIG. 1 is a strainer, and reference numeral 29 is a safety valve that releases the refrigerant pressure on the discharge side of the compressor 16 to the suction side of the compressor 16.

  The controller 13 is installed in the outdoor unit 11 and controls the entire controller 13; a register 13B that stores various data; a RAM 13C and a ROM 13D; an I / O unit 13E that performs an interface operation with the outside; A watchdog timer 13F.

  And the controller 13 controls the driving | operation of the outdoor unit 11 and indoor unit 12A, 12B. Specifically, the controller 13 includes the gas engine 30 (that is, the compressor 16) in the outdoor unit 11, the four-way valve 18, the outdoor fan 20 and the outdoor expansion valve 24, and the indoor expansion valves 22A and 22B in the indoor units 12A and 12B. The indoor fans 23A and 23B are controlled. Further, the controller 13 controls fuel cutoff valves 33A and 33B, which will be described later, and a circulation pump 47 of the engine cooling device 41.

  By switching the four-way valve 18 by the controller 13, the gas heat pump type air conditioner 10 is set to the cooling operation or the heating operation. That is, when the controller 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 the condenser, and the indoor heat exchangers 21A and 21B become the evaporator, and the cooling operation state. Thus, each indoor heat exchanger 21A, 21B cools the room.

  In addition, when the controller 13 switches the four-way valve 18 to the heating side, the refrigerant flows as indicated by broken-line arrows, the indoor heat exchangers 21A and 21B become condensers, and the outdoor heat exchanger 19 becomes an evaporator and are in a heating operation state. Thus, each indoor heat exchanger 21A, 21B heats the room.

  Moreover, the controller 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 controller 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.

  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, fuel cutoff valves 33A and 33B, a zero governor 34, a fuel adjustment valve 35, and an actuator 36 are sequentially arranged in a fuel supply pipe 32, and the end of the fuel supply pipe 32 on the actuator 36 side is a gas. The engine 30 is connected to the combustion chamber.

  The fuel cutoff valves 33A and 33B are arranged in series to form a two-closed type fuel cutoff valve mechanism, and the fuel cutoff valves 33A and 33B are fully closed or fully opened in conjunction with each other to prevent the fuel gas from leaking. Implement communication or alternatives.

  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.

  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.

  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.

  Next, control of the controller 13 will be described.

  In the initial state, it is assumed that the fuel cutoff valve 33A and the fuel cutoff valve 33B are in a state (closed state) in which the supply of fuel gas is shut off.

  When the power is turned on, the controller 13 determines whether or not the controller 13 is operating normally (step S1).

  Specifically, the MPU 13A of the controller 13 determines whether or not the data stored in the register 13B, the RAM 13C, and the ROM 13D is normal. In this case, the data stored in the ROM 13D may be subjected to a data check process such as a parity check once when the power is turned on, but the data stored in the register 13B and the RAM 13C is subjected to various controls. Since it is updated at any stage, it is necessary to check the updated data each time to determine whether the data is normal.

  If it is determined in step S1 that the controller 13 is not normally operable and is abnormal, that is, if the data stored in the register 13B, RAM 13C or ROM 13D is an abnormal value, the processing To the first infinite loop process (step S5).

  As a result, the fuel cutoff valve 33A and the fuel cutoff valve 33B are shifted to a state (closed state) in which the fuel gas supply is shut off by the controller 13, and thereafter, the control of the controller 13 itself is substantially stopped. . That is, unless the user performs a process such as turning on the power again, the controller 13 does not exit the first infinite process loop, and the fuel gas is not unnecessarily supplied.

  If it is determined in step S1 that the operation of the controller 13 is normal, the controller 13 activates a built-in watchdog timer 13F (step S2).

  That is, the controller 13 resets the watchdog timer 13F and starts the count operation of the watchdog timer 13F.

  Next, the controller 13 determines again whether or not the controller 13 can operate normally (step S3). In this case, since the data already stored in the ROM 13D has been checked, the data stored in the register 13B and the RAM 13C is processed as a process for determining whether the controller is operating normally. Check.

  In the determination in step S3, when it is determined that the controller 13 is not normally operable and abnormal (step S3; NG), that is, the data stored in the register 13B or RAM 13C is an abnormal value. The process proceeds to the second infinite loop process (step S6).

  As a result, the fuel cutoff valve 33A and the fuel cutoff valve 33B are shifted to a state (closed state) in which the supply of the fuel gas is shut off, the control of the controller 13 is stopped, and the fuel gas is supplied unnecessarily. There is nothing to do.

  Thereafter, when the count up of the watchdog timer 13F is completed, a watchdog timer interrupt is generated, and the controller 13 exits from the second infinite loop process S6 and performs a watchdog timer operation (step S7).

  That is, the controller 13 stops the operation of the watchdog timer 13F and restarts (reset start). As a result, the process again proceeds to step S1, and it is determined whether or not the controller 13 is operating normally (step S1).

  At this time, the MPU 13A of the controller 13 determines whether or not the data stored in the register 13B, RAM 13C and ROM 13D is normal. If an abnormality is detected, the controller 13 causes the fuel cutoff valve 33A and the fuel to be detected. The shut-off valve 33B is shifted to a state in which the supply of fuel gas is shut off (closed state). Thereafter, the control of the controller 13 is substantially stopped, and the controller is not operated unless the user performs processing such as turning on the power again. No. 13 does not escape from the first infinite processing loop, and fuel gas is not unnecessarily supplied.

  On the other hand, if it is determined in step S3 that the operation of the controller 13 is normal (step S3; OK), that is, if the data stored in the register 13B or RAM 13C is a normal value, The process proceeds to the gas engine control process (step S4).

  Here, the gas engine control process will be described.

  Specifically, the control of the gas engine 30 by the controller 13 includes the fuel cutoff valve 33, the zero governor 34, the fuel adjustment valve 35 and the actuator 36 of the engine fuel supply device 31, and the oil cutoff valve 39 and the oil of the engine oil supply device 37. This is done by the controller 13 controlling the supply pump 40.

  The gas engine 30 is cooled by engine cooling water circulating in the engine cooling device 41. The engine cooling device 41 is connected to the gas engine 30 through an exhaust gas heat exchanger (not shown) attached to the gas engine 30 at one end, and has a substantially closed loop shape in which the other end is directly connected to the gas engine 30. A wax three-way valve 43, a radiator 46 and a circulation pump 47 are sequentially arranged in the water pipe 42.

  The circulation pump 47 boosts the engine cooling water during operation and circulates the engine cooling water in the cooling water pipe 42.

  The wax three-way valve 43 is for quickly warming up the gas engine 30. The wax three-way valve 43 has an inlet 43A for the gas engine 30 in the cooling water pipe 42, a low temperature side outlet 43B on the suction side of the circulation pump 47 in the cooling water pipe 42, and a high temperature side outlet 43C on the radiator in the cooling water pipe 42. 46 is connected to each side.

  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 at about 40 ° C., and flows through the gas engine 30 after recovering exhaust heat (heat of exhaust gas) of the gas engine 30. The lever engine 30 is cooled and heated to about 80 ° C. The engine coolant flowing into the wax three-way valve 43 from the gas engine 30 is returned to the circulation pump 47 from the low-temperature side outlet 43B when the temperature is low (for example, 80 ° C. or lower), and the gas engine 30 is quickly warmed up. When the temperature is 80 ° C. or higher, the refrigerant flows from the high temperature side outlet 43C to the radiator 46.

  The radiator 46 radiates engine cooling water and cools the engine cooling water to about 40 ° C. The engine cooling water cooled by the radiator 46 is returned to the exhaust gas heat exchanger of the gas engine 30 through the suction side of the circulation pump 47 to cool the gas engine 30. The radiator 46 is disposed adjacent to the outdoor heat exchanger 19 of the air conditioner 10.

  During cooling or heating operation of the air conditioner 10, the circulation pump 47 of the engine cooling device 41 is operated to circulate the engine cooling water, and the engine cooling water cools the gas engine 30. The engine cooling water that has cooled the gas engine 30 is radiated by the radiator 46 and cooled. In particular, during the heating operation of the air conditioner 10, the heat radiated by the radiator 46 is taken into the outdoor heat exchanger 19 functioning as an evaporator and used as a heat source of the evaporator.

  As described above, according to the present embodiment, when a malfunction of the controller 13 (including a defective control data) is detected either before the start of the watchdog timer or before the transition to the gas engine control process, it is infinite. The process shifts to the loop process, and immediately before the watchdog timer is started, and after the watchdog timer is started, the fuel cutoff valve 33A and the fuel cutoff valve 33B shut off the supply of fuel gas before starting the gas engine control process. Therefore, the state in which the supply of the fuel gas is surely cut off can be maintained.

  In the above description, the case where the controller 13 controls the fuel cutoff valve 33A and the fuel cutoff valve 33B as controlled parts has been described. However, when the controller 13 is not normally operable, the controlled part is As long as the fuel supply is cut off by the above, fail safe is required, the same can be applied. Specifically, such controlled units include a storage unit that stores various data, an A / D conversion unit for an analog sensor (such as a temperature sensor), and the like.

It is a systematic diagram of the air harmony device of an embodiment. It is an operation | movement flowchart of embodiment.

Explanation of symbols

10 air conditioner 13 controller (control unit, operation state determination unit, shut-off state holding unit)
13A MPU
13B register (data storage unit)
13C RAM (data storage unit)
13D ROM (data storage unit)

Claims (5)

In an air conditioner configured such that a compressor mounted on an outdoor unit is driven by an engine and fuel is supplied to the engine via a fuel cutoff valve.
The control unit that controls the operation of the engine and the fuel cutoff valve as the controlled unit and the activation of the air conditioner determines whether or not it can operate normally during the operation of the air conditioner. A discriminator;
A shut-off state holding unit that holds a state in which the fuel shut-off valve shuts off the fuel supply when it is determined by the determination that the device is not normally operable;
A watchdog timer for performing a watchdog interrupt for performing a restart process of the air conditioner ,
The control unit determines whether or not the operation state determination unit can normally operate again after the restart process is performed in a state where the fuel supply to the engine is cut off by the cut-off state holding unit. Determining and prohibiting the restart process by the watchdog interrupt when it is determined that the operation state determination unit is not normally operable.
An air conditioner characterized by that. The air conditioner according to claim 1, wherein
The air conditioner characterized in that the controlled part should be in a state where the fuel supply is shut off by the fuel cutoff valve when the control part cannot operate normally. In the air conditioning apparatus according to claim 2,
The air conditioner characterized in that the controlled part is one of a storage part for storing various data and an analog sensor A / D conversion part. The air conditioner according to claim 1 or 2,
The control unit includes a data storage unit that stores various data as the controlled unit.
The air conditioner characterized in that the operation state determination unit determines whether or not the device can normally operate based on whether or not the data stored in the data storage unit is normal. In the air conditioning apparatus according to claim 2,
The air conditioning apparatus, wherein the data storage unit includes at least one of a register, a RAM, and a ROM.

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