JP2012172956A - Engine drive type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constitution of an air conditioner capable of restarting an operation without standby time under a condition where an operation of a refrigeration device can be immediately restarted after power restoration.SOLUTION: The engine drive type air conditioner 1 drives compressors 1a and 1b by an engine and includes electrical components such as solenoid valves SV0, SV1, SV2, and SV3 of a refrigerant circuit, electric expansion valves EV1, EV2, and EV3, and an outdoor fan 20. When an instruction of an air conditioning operation is received at the restart of a power supply after a main power supply of the electrical components is switched off, a controller unit of the air conditioner eliminates the standby time and starts an air conditioning operation so long as at least one of the following conditions is met: the detected temperatures TO1 and TO2 of returned oil from an oil separator 4 to the compressors 1a and 1b are a first predetermined value T1 higher than a saturated vapor pressure temperature SHD determined by a detected pressure PH1 of a pressure sensor S11 provided in a discharge line 11; the detected temperatures TD1 and TD2 of the discharge line 11 are a predetermined second value T2 higher than the saturated vapor pressure temperature SHD; and the detected water temperature TEC of engine cooling water is a predetermined third value T3 higher than an outdoor temperature TE.

Description

  The present invention relates to an engine-driven air conditioner having a restart control function when power is restored after a power failure.

  Conventionally, as a refrigeration apparatus for a vending machine, an apparatus having a restart control configuration at the time of power recovery from a power failure has been disclosed (for example, see Patent Document 1).

JP-A-7-152958

  However, the configuration of the restart control in the conventional refrigeration apparatus is a structure that secures a predetermined standby time T0 from the time when the power failure occurs, and when the time until power recovery is longer than T0, the refrigeration apparatus immediately after power recovery However, even if the time until power recovery is shorter than T0 and the operation of the refrigeration system can be restarted immediately after power recovery, it is necessary to wait for T0 time from the time of the power failure.

  Therefore, the present invention presents a configuration of an air conditioner that can resume operation without waiting time under conditions where the operation of the refrigeration apparatus can be resumed immediately after power recovery.

  The engine-driven air conditioner of the present invention for solving the above problems is an engine-driven air conditioner that drives a compressor with an engine and has electrical components such as an electromagnetic valve of a refrigerant circuit, an electric expansion valve, and an outdoor fan. Saturated vapor pressure temperature at which the detected oil temperature of the return oil from the oil separator to the compressor is determined from the detected pressure of the discharge line when power supply is resumed after the main power of the electrical component is turned off and an air conditioning operation command is received More than the first predetermined value, the detected temperature of the discharge line is a second predetermined value or more than the saturated vapor pressure temperature, or the detected water temperature of the engine coolant is a third predetermined value or more than the outside air temperature. When even one of these conditions is satisfied, the control unit starts the air-conditioning operation while omitting the standby time. The engine-driven air conditioner has a plurality of compressors, and discharges to any one of the detected oil temperatures of the return oil to each compressor or to the junction of each compressor. When any one of the detected temperatures of the line satisfies the condition described in claim 1, the controller has a control unit that starts the air conditioning operation while omitting the standby time.

  As described above, according to the present invention, when a power failure occurs during operation and power is restored in a short time, such as when power supply is resumed in a short time after the main power is turned off, there is no fear of liquid back, Air conditioning operation can be started early without waiting time.

  The same effect as described above can be obtained even in an air conditioner having a plurality of compressors.

It is a refrigerant circuit figure explaining the flow of the refrigerant at the time of heating of the engine drive type air conditioner concerning the present invention. It is a refrigerant circuit figure explaining the flow of the refrigerant at the time of air conditioning of the engine drive type air-conditioner concerning the present invention. It is a control block diagram of the engine drive type air conditioner concerning the present invention. It is a control flow figure of the engine drive type air conditioner concerning the present invention.

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

  1 and 2 show an outline of a refrigerant circuit of an engine-driven air conditioner (hereinafter simply referred to as an air conditioner) 1, and FIG. 3 performs restart control when the air conditioner 1 recovers from a power failure. The configuration of the control unit 10 is shown, and FIG. 4 shows the control flow.

  The air conditioner 1 drives compressors 1a and 1b with an engine (not shown), and includes electrical components such as solenoid valves SV0, SV1, SV2, and SV3, electric expansion valves EV1, EV2, and EV3, an outdoor fan 20, and an indoor fan 30. The oil separator 4 is provided in the discharge line 11 of the compressors 1a and 1b, and the oil return line 12 from the oil separator 4 to the compressors 1a and 1b is provided. When the power supply is resumed after being turned off and an air conditioning operation command is received, the detected oil temperatures TO1 and TO2 of the return oil of the oil return line 12 from the oil separator 4 to the compressors 1a and 1b are provided in the discharge line 11. The first predetermined value T1 or more than the saturated vapor pressure temperature SHD determined by the detected pressure PH1 of S11, and the discharge temperature TD of the discharge line 11 is second than the saturated vapor pressure temperature SHD. When the air-conditioning operation is performed with the standby time omitted, when the engine coolant temperature detection temperature TEC satisfies any one of the predetermined value T2 or more, or the third predetermined value T3 or more than the outside air temperature TE. It is what is started.

  First, the flow of refrigerant and oil during heating and cooling of the air conditioner 1 will be described.

  During the cooling operation, the air conditioner 1 connects the discharge lines 11 of the compressors 1a and 1b to the outdoor heat exchangers 2a and 2b, and connects the suction lines 13 of the compressors 1a and 1b to the indoor heat exchanger 3 for heating. During operation, a four-way valve 5 is provided for connecting the discharge lines 11 of the compressors 1a and 1b to the indoor heat exchanger 3 and connecting the suction line 13 of the compressors 1a and 1b to the outdoor heat exchangers 2a and 2b. An engine (not shown) that drives 1a and 1b is provided, a receiver 6 is provided in a liquid pipe line 14 that connects the outdoor heat exchangers 2a and 2b and the indoor heat exchanger 3, and the outdoor is provided downstream of the receiver 6 during heating operation. A sub-evaporator 7 made of engine cooling water is provided in parallel with the heat exchangers 2a and 2b, and a downstream line 15 of the sub-evaporator 7 is connected to an intake line 13 extending from the four-way valve 5 to the compressor intake port, and an outdoor heat exchanger The first outdoor electric expansion valve EV1 is provided in the connection line 16 between the a and 2b and the receiver 6, the second outdoor electric expansion valve EV2 is provided in the connection line 17 between the sub-evaporator 7 and the receiver 6, and the downstream line 15 of the sub-evaporator 7 The opening degree of the first outdoor electric expansion valve EV1 is controlled on the basis of the degree of refrigerant superheating downstream of the connection portion with the suction line 13 extending from the four-way valve 4 to the compressor suction port. The air conditioner 1 introduces the refrigerant compressed by the compressors 1a and 1b into the oil separator 4 via the discharge line 11 from the compressors 1a and 1b, and separates the refrigerant into oil. .

  Among these, as shown in FIG. 1, in the heating operation, the refrigerant is radiated by the indoor heat exchanger 3 through the four-way valve 5 to be condensed and liquefied, and then stored in the receiver 6 through the bridge circuit 8. The liquid refrigerant passes through the bridge circuit 8 again and is evaporated and evaporated in the outdoor heat exchangers 2a and 2b by adjusting the opening degree of the electric expansion valve EV1, and then enters the accumulator 9. At this time, the saturated vapor pressure temperature of the refrigerant is calculated from the detected pressure PL1 of the pressure sensor S1 provided in the suction line 13 to the compressors 1a and 1b, and measured from the temperature sensor S3 before entering the accumulator 9 from this calculated temperature. The opening degree of the electric expansion valve EV1 is controlled and supplied so that the detected temperature TS2 of the actual refrigerant to be a superheat degree equal to or higher than a predetermined temperature.

  Still, when the detected temperature TS2 of the refrigerant measured from the temperature sensor S3 before entering the accumulator 9 is low and the actual degree of superheat of the refrigerant is too small, the opening degree of the electric expansion valve EV1 is reduced. Further, when the outdoor air temperature is low and the outdoor heat exchangers 4a and 4b cannot sufficiently evaporate the refrigerant, the refrigerant is caused to flow to the sub-evaporator 7 by controlling the opening degree of the electric expansion valve EV2, and the engine (illustrated) It is supplied to the accumulator 9 after being sufficiently superheated by the waste heat (not shown). At this time, the detected temperature TS3 of the refrigerant supplied through the sub-evaporator 7 is measured by the temperature sensor S4.

  Here, when both the outdoor heat exchangers 4a and 4b and the sub-evaporator 8 are used as the refrigerant, the opening degree control of the electric expansion valve EV2 is based on the detected temperature TS3 of the refrigerant measured from the temperature sensor S4. Is performed so as to be equal to or higher than a predetermined temperature than the detected refrigerant temperature TS2. In this way, while maintaining the opening degree of the electric expansion valve EV1, that is, while ensuring the refrigerant flow rate to the outdoor heat exchangers 2a and 2b and suppressing the pressure loss in the sub-evaporator 7, the degree of superheat of the refrigerant after merging Can be maintained at a predetermined temperature.

  Thereafter, the refrigerant is sucked again from the accumulator 9 through the refrigerant suction line 13 to the compressors 1a and 1b.

  On the other hand, the oil passes through the capillary CT0 or the on-off valve SV0 provided on the oil return line 12 from the bottom of the oil separator 4, and then compressed through the on-off valves SV1, SV2, capillaries CT1, CT2, and oil temperature sensors S5, S6. Returned to machine 1a, 1b. The oil in the vicinity of the oil level in the oil separator 4 is returned from the oil return line 18 to the compressors 1a and 1b from the refrigerant suction line 13 via the on-off valve SV3, capillary CT3, and oil temperature sensor S7.

  In the case of the cooling operation, as shown in FIG. 2, the refrigerant radiates heat in the outdoor heat exchangers 2 a and 2 b through the four-way valve 5 to be condensed and liquefied, and is then stored in the receiver 6. This liquid refrigerant evaporates and evaporates in the indoor heat exchanger 3 by adjusting the opening degree of the electric expansion valve EV3 through the bridge circuit 8, and then enters the accumulator 9. When the degree of superheat of the gas refrigerant that has entered the accumulator 9 is too small, the refrigerant is caused to flow to the sub-evaporator 7 by controlling the opening degree of the electric expansion valve EV2, and the sub-evaporator 7 is sufficiently affected by the waste heat of the engine (not shown). Is supplied to the accumulator 9 after being heated as a gas refrigerant.

  Also in this case, the oil passes through the capillary CT0 or the on-off valve SV0 provided in the oil return line 12, and then goes to the compressors 1a and 1b through the on-off valves SV1 and SV2, capillaries CT1 and CT2, and oil temperature sensors S5 and S6. Will be returned. The oil in the vicinity of the oil level in the oil separator 4 is returned from the oil return line 18 to the compressors 1a and 1b from the refrigerant suction line 13 via the on-off valve SV3, capillary CT3, and oil temperature sensor S7.

  The compressors 1a and 1b may be operated by only one unit, or may be operated by both units. In the case of operation of only one unit, the on-off valve SV2 is closed, the supply of oil to the compressor 1b is stopped, and only the compressor 1a is operated. In this case, the refrigerant discharged from the compressor 1a is prevented from flowing back to the compressor 1b by the check valve CV1 provided downstream of the discharge port of the compressor 1b. Opening and closing of the on-off valves SV1 and SV2 is interlocked with the start and stop of the compressors 1a and 1b, respectively.

  Further, the discharge temperatures TD1 and TD2 of the refrigerant discharged from the compressors 1a and 1b are temperature sensors S8 and S8 provided at respective positions before being discharged from the compressors 1a and 1b and joining the discharge line 11, respectively. Measured by S9. A temperature sensor S10 may be provided in the discharge line 11 after merging to measure the refrigerant discharge temperature TD. The discharge pressure PH1 of the refrigerant discharged from the compressors 1a and 1b is measured by a pressure sensor S11 provided in the discharge line 11. The outside air temperature TE where the outdoor unit A of the air conditioner 1 is disposed is measured by a temperature sensor S12 provided in the casing of the outdoor unit A, and the engine coolant temperature TEC is heat exchanged in the sub-evaporator 7. Then, the temperature is measured by the temperature sensor S13 provided at the position of the engine coolant passage 71.

  Further, in FIG. 1 and FIG. 2, the air conditioner 1 is connected to only one indoor unit B with respect to one outdoor unit A, but a plurality of indoor units are provided between the closing valves BV1 and BV2. Machine B can be connected. Further, one or two or more compressors 1a and 1b are operated according to the operation status of the connected indoor units B.

  In general, the air conditioner 1 configured in this manner is configured such that the liquid in the accumulator 9 is provided by the heater 91 provided in the accumulator 9 so that the compressors 1a and 1b do not suck the liquid refrigerant and cause liquid compression. Heat the refrigerant. This prevents the liquid refrigerant from sleeping in the accumulator 9 while the air conditioner 1 is on standby. After the operation of the compressors 1a and 1b is started, the compressors 1a and 1b are stopped when the indoor temperature reaches the target temperature, and when the temperature is lower than the target temperature, the compressors 1a and 1b are started again. By doing so, the temperature is adjusted. Since the operation stop and operation start of the compressors 1a and 1b are controlled by the control unit 10, normally there is no fear of liquid compression, but the entire air conditioner 1 as in the case of a power failure, When the main power supply is stopped, the control of the control unit 10 is interrupted.

  Then, next, restart control when power is restored from a power failure in the air conditioner 1 will be described.

  First, when the main power supply is restored, the control unit 10 of the air conditioner 1 checks whether or not the normal operation state has been properly stopped (step 1). This confirmation can be easily determined by confirming whether the control system of the air conditioner 1 has been properly terminated or whether the power has been turned off without being terminated.

  If it is confirmed that the air conditioner has been properly stopped, the air conditioner 1 is in a stopped state even if the main power is restored unless the start switch (not shown) of the air conditioner 1 is turned on. The startup operation is not performed (step 2).

  If the power supply is stopped from the normal operation state instead of being stopped normally, it means that a power failure occurred during the operation of the air conditioner 1, and then the power was restored. The controller 10 immediately collects temperature information and pressure information from each of the sensors S1 to S13 and grasps the current state (step 3).

  First, saturated steam in which the detected oil temperatures TO1 and TO2 of the return oil temperature sensors S5 and S6 from the oil separator 4 to the compressors 1a and 1b are determined by the detected pressure PH1 of the pressure sensor S11 provided in the discharge line 11 is used. It is confirmed whether or not the pressure temperature SHD is higher than the first predetermined value T1 (step 4).

  At this time, the detected oil temperatures TO1 and TO2 of the return oil have a certain relationship with the saturated vapor pressure temperature SHD during normal operation. However, when time elapses after a power failure, the detected oil temperatures TO1 and TO2 of the oil decrease. Therefore, it is determined whether or not the detected oil temperatures TO1 and TO2 are higher than the saturated vapor pressure temperature SHD by the first predetermined value T1 or more to determine how much time has elapsed since the power failure. Can be a guide.

  Therefore, if any one of the detected oil temperatures TO1 and TO2 is higher than the first predetermined value T1, it is determined that not much time has elapsed since the power failure, the restart operation is omitted, and the air conditioning operation is started. (Step 7).

  If it is less than the first predetermined value T1, it is confirmed whether or not the detected temperature TD of the temperature sensor S10 provided in the discharge line 11 is higher than the second predetermined value T2 above the saturated vapor pressure temperature SHD (step 5). ).

  Instead of the detection temperature TD at S10, the determination may be made based on the detection temperatures TD1 and TD2 at S8. However, when the compressor 1b is stopped only by the operation of the compressor 1a, it is conceivable that the detected temperature TD2 in S9 has not risen. Therefore, in this case, the detected temperature TD in S10 or S8 Judgment is made based on the detected temperature TD1.

  At this time, the detected temperatures TD, TD1, and TD2 of the refrigerant discharge line 11 have a certain relationship with the saturated vapor pressure temperature SHD during normal operation. However, when time elapses after a power failure, the detected temperatures TD, TD1, and TD2 of the refrigerant discharge line 11 decrease. Therefore, by checking whether or not the detected temperatures TD, TD1, and TD2 of the discharge line 11 are higher than the saturated vapor pressure temperature SHD by the second predetermined value T2, how much time has elapsed since the power failure. It can be used as a guide for judging whether or not there is.

  Therefore, if the temperature is higher than the second predetermined value T2, it is determined that not much time has elapsed since the power failure, the restart operation is omitted, and the air conditioning operation is started (step 7).

  If it is less than the second predetermined value T2, it is confirmed whether or not the detected temperature TEC of the engine coolant is higher than the third predetermined value T3 by the outside air temperature TE (step 6).

  At this time, the detected temperature TEC of the engine coolant has a certain relationship with the outside air temperature TE. However, when time elapses after a power failure, the detected temperature TEC of the engine cooling water decreases. Therefore, by checking whether or not the detected temperature TEC is higher than the outside air temperature TE by a third predetermined value T3 or more, it can be used as a guideline for determining how much time has passed since the power failure.

  Therefore, if it is equal to or greater than the third predetermined value T3, it is determined that not much time has elapsed since the power failure, the restart operation is omitted, and the air conditioning operation is started (step 7).

  If it is less than the third predetermined value T3, it is determined that the degree of superheat of the refrigerant is insufficient, and the restart operation is started. After the completion, the air conditioning operation is started (step 8).

  In the restart operation, an operation for heating the liquid refrigerant in the accumulator 9 is performed by the heater 91 provided in the accumulator 9.

  In the air conditioning operation, after the engine is started and the control system is started, a normal operation in which the refrigerant is circulated by the compressors 1a and 1b is started.

  Steps 4 to 6 described above may be switched in order or may be performed in parallel.

  The first predetermined value T1, the second predetermined value T2, and the third predetermined value T3 are appropriately determined according to the refrigerant used, the design of the air conditioner 1, and the like.

  According to the air conditioner 1 configured in this way, when power is resumed in a short time after the main power is shut off, such as when a power failure occurs during operation of the air conditioner 1 and power is restored in a short time, If the refrigerant in the refrigerant circuit is maintained in a sufficiently superheated state, and it is determined that liquid back does not occur even if the compressors 1a and 1b are restarted, the time required for the restart operation The air conditioning operation can be resumed at an early stage by omitting.

  In addition, in this Embodiment, the control part 10 is performing various other control, However, In this invention, only the control content regarding restart is disclosed.

  Moreover, the said control part 10 installs the control program in the control part 10 of the existing air conditioner 1, Even if it is the said existing air conditioner 1, the restart control of the air conditioner 1 is performed similarly to the above. It can be performed. However, the control program is executed by calculating the return oil detected oil temperatures TO1, TO2, the detected temperatures TD1, TD2, TD of the discharge path 11, the saturated vapor pressure temperature SHD from the discharge pressure PH1 of the discharge path 11, and the engine cooling Since it is necessary to measure the detected water temperature TEC and the outside air temperature TE of the water, if the existing air conditioner 1 does not have sensors S5, S6, S8, S9, S10, S11, S12, and S13 for performing these measurements, these It is necessary to install the sensor.

  The air conditioner according to the present invention is used for an engine-driven air conditioner.

DESCRIPTION OF SYMBOLS 1 Engine drive type air conditioner 1a, 1b Compressor 10 Control part 11 Discharge line 11a Discharge line 11b Discharge line 20 Outdoor fan (electrical equipment)
30 Indoor fans (electrical components)
4 Oil separator SV1 Solenoid valve (Electrical component)
SV2 solenoid valve (electrical component)
SV3 solenoid valve (electrical equipment)
EV1 Electric expansion valve (Electrical component)
EV2 Electric expansion valve (Electrical component)
EV3 Electric expansion valve (Electrical component)
TO1 Detected oil temperature TO2 Detected hot water temperature TD1 Detected temperature TD2 Detected temperature SHD Theoretical discharge temperature TEC Detected water temperature TE Outside air temperature

Claims (2)

In an engine-driven air conditioner that drives a compressor with an engine and has electrical components such as an electromagnetic valve of a refrigerant circuit, an electric expansion valve, and an outdoor fan,
Saturated vapor pressure temperature at which the detected oil temperature of the return oil from the oil separator to the compressor is determined from the detected pressure of the discharge line when power supply is resumed after the main power of the electrical component is turned off and an air conditioning operation command is received More than the first predetermined value, the detected temperature of the discharge line is a second predetermined value or more than the saturated vapor pressure temperature, or the detected water temperature of the engine coolant is a third predetermined value or more than the outside air temperature. An engine-driven air conditioner having a control unit that starts the air-conditioning operation while omitting the standby time when any one of the conditions is satisfied. The engine-driven air conditioner according to claim 1,
It has a plurality of compressors, any one of the detected oil temperatures of the return oil to each compressor, or any one of the detected temperatures of the discharge line up to the junction of each compressor When the condition of Claim 1 is satisfy | filled, the engine drive type air conditioner which has a control part which abbreviate | omits standby | waiting time and starts an air conditioning driving | operation.

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