JP3477293B2 - Engine driven air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an engine-driven air conditioner.

[0002]

2. Description of the Related Art A system diagram of a conventional engine-driven air conditioner is shown in FIG. As shown in FIG. 4, the compressor 2, which is driven by the engine 1 with the starter motor 11, the four-way valve 3, the outdoor heat exchanger 4, the throttle mechanism 5, and the indoor heat exchanger 6 are connected by a refrigerant pipe to perform refrigeration. The cycle is made up.

During cooling operation, the compressor 2 is driven by the engine 1.
When is driven, the gas refrigerant discharged from the compressor 2 enters the outdoor heat exchanger 4 via the four-way valve 3 and radiates heat to the outside air blown by the outdoor fan 7 as shown by the solid arrow. It is condensed and liquefied.

This liquid refrigerant is adiabatically expanded in the process of passing through the throttling mechanism 5, and then enters the indoor heat exchanger 6, where the indoor air sent by the indoor fan 8 is cooled and vaporized. Then, the gas refrigerant returns to the compressor 2 via the four-way valve 3.

During the heating operation, the four-way valve 3 is switched in the opposite direction, and the refrigerant discharged from the compressor 2 has the four-way valve 3, the indoor heat exchanger 6, the throttling mechanism 5 and the outdoor as shown by the broken line arrow. After passing through the heat exchanger 4 and the four-way valve 3 in this order, the compressor 2
Return to.

The cooling water whose temperature has risen by cooling the engine 1 enters the radiator 9 where it radiates heat to the outside air sent by the outdoor fan 7 to lower the temperature.
It is energized by the cooling water circulation pump 10 and returns to the engine 1.

A crankcase heater 13 is attached to the crankcase 2A of the compressor 2 in order to prevent the liquid refrigerant from sleeping while the compressor 2 is stopped.

[0008]

In the above-described conventional air conditioner, when the crankcase heater 13 is de-energized at the time of trial operation or long-term stoppage, it is stored in the crankcase 2A of the compressor 2. A large amount of liquid refrigerant dissolves in the freezing machine oil. When the engine 1 is started in this state,
The liquid refrigerant dissolved in the refrigerating machine oil may cause lubrication failure of the compressor 2 to cause seizure or abnormal wear.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been invented to solve the above-mentioned problems, and its gist is to provide a compressor with a crankcase heater driven by an engine, and an outdoor heat exchange. In an engine-driven air conditioner equipped with a refrigeration cycle in which an air conditioner and an indoor heat exchanger are connected by a refrigerant pipe, load control means for operating the engine at a target speed corresponding to an air conditioning load, and the crankcase heater In addition to providing an integrating means for integrating the energization time to the engine, when the integrated time is within a predetermined time at the time of starting the engine, the engine speed at the engine speed of n ₁ per unit time is set as a target corresponding to the air conditioning load. accelerates to rotation speed, the integration time is the rotational speed of the engine corresponding to the air conditioning load in the rotational speed of the predetermined unit time is hours or more when the n ₁ less than n ₂ In an engine driving type air conditioner which is characterized in that a start control means for accelerating to the target speed.

Another feature is that when the engine is stopped and restarted during acceleration at a rotational speed of n ₂ per unit time within a set time after completion of the engine start, after completion of engine start There is provided restart control means for accelerating at a rotation speed of n ₁ per unit time up to the stop rotation speed, and then accelerating at a rotation speed of n ₂ per unit time until the set time elapses.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention is shown in FIGS. 1 to 3, FIG. 1 is a system diagram, FIG. 2 is a control flowchart, and FIG. 3 is a time chart.

As shown in FIG. 1, a rotation speed detector 27 for detecting the rotation speed of the engine 1 is provided, and the rotation speed of the engine 1 is controlled by the controller 20. This control device 20 includes start control means 21, restart control means 22, load control means 23,
Operating time accumulating means 24, switching means 25, energizing time accumulating means 26
It is equipped with.

The rotation speed detected by the rotation speed detector 27 is input to the start control means 21, the restart control means 22, the operating time integration means 24 and the switching means 25. The signal from the crankcase heater 13 is input to the energization time integration means 26, where the energization time of the crankcase heater 13 is integrated.

The room temperature detected by the room temperature sensor 28 is input to the load control means 23, and the target rotation speed corresponding to the air conditioning load is determined by comparing the room temperature with the set temperature input from the room temperature setting device 29.

The start control means 21 receives signals from the rotation speed detector 27 and the energization time integration means 26 to control the rotation speed of the engine 1 at the time of starting. The operating time integration means 24 receives a signal from the rotation speed detector 27 and integrates the operating time of the engine 1.

The restart control means 22 receives signals from the rotation speed detector 27, the operating time integration means 24 and the start control means 21 to control the rotation speed of the engine 1 at the time of restart. The switching means 25 receives signals from the start control means 21, the restart control means 22, the load control means 23 and the operation switch 30 and outputs them to the engine 1 and the starter motor 11.

As shown in FIG. 2, when the engine 1 is stopped by turning off the operation switch 30, the crankcase heater 13 is energized, and the energization time is integrated by the integration means 26.

When the operation switch 30 is turned on, the room temperature sensor 28 detects the room temperature, the load control means 23 calculates the air conditioning load, and the target rotation speed corresponding to the air conditioning load is determined. Then, the starter motor 11 is activated by a command from the switching means 25, and the starter motor 11 drives the engine 1 and the compressor 2.

As shown in FIG. 3, when the rotational speed of the engine 1 rises to about 300 rpm, the engine 1 is ignited and started. Furthermore, the starter motor 11 is disconnected from the engine 1 and stopped when the rotation speed of the engine 1 reaches about 500 rpm, and the start of the engine 1 is completed when the rotation speed of the engine 1 reaches about 1100 rpm. To do.

The time from when the engine 1 is stopped until the operation switch 30 is turned on, that is, the energization time of the crankcase heater 13 accumulated by the energization time accumulating means 26 is a predetermined time T ₁
If it is within (for example, 10 hours), the start control means 21 sets the increase amount of the rotation speed of the engine 1 per unit time t to n ₁ . As a result, after the start of the engine 1 is completed, the engine 1 is accelerated at a rate of n ₁ per unit time t until the target rotation speed corresponding to the air conditioning load is reached, and the rotation speed increases with the inclination a as shown in FIG. To do.

If the energizing time accumulated by the energizing time accumulating means 26 is equal to or longer than the predetermined time T ₁ , the starting control means 21 determines the increase amount per unit time t to be n ₂ . by this,
The engine 1 is accelerated at a rate of n ₂ smaller than n ₁ per unit time t until reaching the target rotation speed corresponding to the air conditioning load,
The number of rotations increases as shown by the inclination B in FIG. After reaching the target rotation speed, if the target rotation speed changes according to the fluctuation of the air conditioning load, the rotation speed of the engine 1 also changes accordingly.

When the engine 1 is stopped and restarted before the predetermined operating time T ₂ (for example, 5 minutes) is reached during acceleration with the increase amount n ₂ after the completion of the start of the engine 1, the restart control means The number of revolutions of the engine 1 is controlled by 22 and the operating time accumulating means 24 integrates the operating time after the engine 1 has been started until the engine 1 is stopped.

At the time of restart, the engine 1 is started in the same manner as at the time of the previous start, but after the completion of the start, the ratio of n ₁ per unit time t until the number of revolutions N ₁ stopped at the time of the previous start is reached. The acceleration is carried out at, and after the number of revolutions N ₁ is reached, it is accelerated at a rate of n ₂ per unit time t until reaching a predetermined integration time T ₂ . Then, after the lapse of the integrated time T _2, the vehicle is accelerated at a rate of n ₁ per unit time until the target rotation speed is reached. After that, when the engine 1 is stopped during acceleration with the increase amount n ₂ , the above is repeated.

However, when the energization time is within a predetermined time, that is, when the amount of liquid refrigerant stagnation in the refrigerating machine oil in the crankcase 24 is small, per unit time until the target rotation speed is reached after the start of the engine 1 is completed. Until the engine 1 can be accelerated with a large increase in the rotation speed n ₁ , the maximum crank capacity can be promptly exhibited.

On the other hand, when the energization time is equal to or longer than the predetermined time T ₁ , the engine 1 is accelerated by the small increment of n ₂ per unit time after the start of the engine 1 is completed,
Even if the liquid refrigerant is sunk in the refrigerating machine oil, it is possible to prevent seizure and abnormal wear of the lubricated parts of the compressor.

Further, the set time T after the start of the engine 1 is completed.
_{When the} engine 1 is stopped while accelerating the engine 1 within an increase amount of the rotational speed n ₂ per unit time within ₂ and when the engine 1 is restarted, until the rotational speed N ₁ stopped at the previous start is reached. Accelerate with a large increment n ₁ , then set time T
Since the acceleration is performed with a small increase n ₂ up to ₂ , the engine speed can be rapidly increased to the target speed while avoiding the engine stop.

[0027]

According to the present invention, when the integrated time is within a predetermined time at the engine start, the engine speed is accelerated to a target speed corresponding to the air conditioning load at a rotational speed of n ₁ per unit time, and integrated. When the time is equal to or longer than the predetermined time, the engine speed is accelerated to a target speed corresponding to the air conditioning load at a rotation speed n ₂ smaller than the above n ₁ per unit time, so the liquid refrigerant is sunk in the refrigeration oil. Even in such a case, it is possible to prevent seizure and abnormal wear of the lubricated parts of the compressor.

When the engine is stopped and restarted during acceleration at a rotation speed of n ₂ per unit time within a set time after completion of engine start, n ₁ per unit time up to stop rotation speed after completion of engine start If you accelerate at the number of revolutions of n ₂ per unit time until the above set time elapses,
It is possible to quickly increase the engine speed to the target speed while avoiding stopping the engine.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a control flowchart of the above embodiment.

FIG. 3 is a time chart in the above embodiment.

FIG. 4 is a system diagram of a conventional engine-driven air conditioner.

[Explanation of symbols]

1 engine 11 Starter motor 2 compressor 2A crankcase 13 Crankcase heater 4 outdoor heat exchanger 5 Aperture mechanism 6 Indoor heat exchanger 27 RPM detector 20 Control device

Front page continuation (72) Inventor Michio Yoneda 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya-shi Sanryo Heavy Industries Co., Ltd. Nagoya Research Laboratory (72) Inventor Tadahiro Kato, Asahi-cho, 3-chome, Nishibiwajima-cho, Nishikasugai-gun, Aichi Prefecture No. 1 Mitsubishi Heavy Industries, Ltd. Aircon Works (58) Fields surveyed (Int.Cl. ⁷ , DB name) F25B 1/00 341 F25B 1/00 351 F25B 27/00 F25B 1/00 371 F25B 1/00 361

Claims (2)

(57) [Claims] 1. An engine-driven air conditioner equipped with a refrigerating cycle in which a compressor driven by an engine and equipped with a crankcase heater, an outdoor heat exchanger, and an indoor heat exchanger are connected by a refrigerant pipe. Is provided with load control means for operating at a target speed corresponding to the air conditioning load, and integrating means for integrating the energization time to the crankcase heater, and when the integrated time is within a predetermined time at the time of starting the engine, When the engine speed is n ₁ per unit time, the engine speed is accelerated to the target speed corresponding to the air conditioning load, and when the accumulated time is more than a predetermined time, the engine speed is n ₂ less than n ₁ per unit time. 2. An engine-driven air conditioner characterized by comprising start control means for accelerating the engine speed to a target speed corresponding to an air conditioning load. _{2. When} the engine is stopped and restarted during acceleration at a rotational speed of n ₂ per unit time within a set time after completion of the start of the engine, the unit is up to the stopped rotational speed after completion of the start of the engine. _2. The engine-driven system according to claim 1, further comprising restart control means for accelerating at a rotation speed of n ₁ per hour and thereafter accelerating at a rotation speed of n ₂ per unit time until the set time elapses. Air conditioner.