JPH08233399A - Engine-driven type air-conditioner - Google Patents

Abstract

PURPOSE: To prevent a compressor in a refrigerant flooded state from being damaged due to liquid compression and defective lubrication when operation is restarted after the stop of an air-conditioner for a long time. CONSTITUTION: A running-in means 28 is provided to effect running-in of an engine 1 at the given number of revolutions lower than the number of revolutions decided by a warming-up operation means 26 when during the starting of an engine 1, a compressor 2 is in a refrigerant flooded state. When an engine cooling water temperature is increased to a warming-up completion temperature through warming-up operation or running-in operation, the number of revolutions is switched to a value responding to an air-conditioning load, decided by a number of revolutions control means 23, by a switching means 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine-driven air conditioner having a compressor driven by a water-cooled engine.

[0002]

2. Description of the Related Art In a conventional engine-driven air conditioner, when restarting operation after a long stop, the engine is warmed up until the temperature of the engine cooling water rises to a predetermined temperature (for example, 60 ° C.). ing. After the warm-up operation is completed,
The engine is operated at a rotation speed according to the air conditioning load.

As shown in FIG. 4, the engine speed during warm-up operation is determined according to the temperature of the cooling water, and is set to be high when the water temperature is low.

[0004]

When the conventional engine-driven air conditioner is stopped for a long time, a large amount of liquid refrigerant accumulates in the compressor and dilutes the lubricating oil, resulting in a so-called refrigerant stagnation state. When the operation of the air conditioner is restarted in this state, if the temperature of the cooling water is low, the engine will be warmed up at a high speed corresponding to this temperature, so the compressor directly connected to this engine will rotate at a high speed. There is a risk that the liquid refrigerant that has been rotated by several numbers may be compressed by the liquid refrigerant accumulated therein or damaged due to poor lubrication due to diluted lubricating oil.

[0005]

SUMMARY OF THE INVENTION The present invention has been invented to solve the above problems, and its gist is to provide a compressor driven by a water-cooled engine,
A refrigeration cycle consisting of an outdoor heat exchanger, a throttle mechanism, an indoor heat exchanger, etc., an engine speed control means for operating the engine at a speed corresponding to an air conditioning load, and a temperature of the cooling water at the time of starting the engine. In an engine-driven air conditioner equipped with warm-up operation means that operates at a rotational speed determined according to the detection means, a detection means for detecting the refrigerant stagnation state of the compressor when the engine is started, and this detection means. When the state is detected, the familiar operating means for operating the engine at a predetermined rotational speed lower than the rotational speed determined by the warm-up operating means, and the rotational speed control means when the temperature of the cooling water rises to the warm-up end temperature. According to another aspect of the present invention, there is provided an engine-driven air conditioner characterized by including switching means for switching to a rotation speed corresponding to an air conditioning load determined by.

The detection means may be composed of a timer for accumulating the stop time of the compressor before starting.

[0007]

In the present invention, when the detection means including a timer does not detect the refrigerant stagnation state of the compressor when the engine is started, the engine is warmed up at the rotation speed determined by the warming-up operation means. When the detection unit detects the refrigerant stagnation state of the compressor, the engine is acclimated to operate at the predetermined rotation speed determined by the acclimation operation unit.

When the temperature of the cooling water rises to the warm-up operation end temperature due to the warm-up operation or the acclimation operation, the engine is operated by switching to the rotation speed corresponding to the air conditioning load determined by the engine rotation speed control means by the switching means. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the present invention is shown in FIGS. As shown in FIG. 1, a compressor 2, which is driven by a water-cooled engine 1, a four-way valve 3, an outdoor heat exchanger 4, a throttle mechanism 5, an indoor heat exchanger 6 and the like constitute a refrigeration cycle.

During the 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 as shown by the solid arrow, and radiates heat to the outside air blown by the outdoor fan 7 there. 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 blown by the indoor fan 8 is cooled and vaporized. After this, this gas refrigerant is used as a four-way valve 3.
Return to compressor 2 via.

During the heating operation, the refrigerant discharged from the compressor 2 passes through the four-way valve 3, the indoor heat exchanger 6, the throttle mechanism 5, the outdoor heat exchanger 4, and the four-way valve 3 in this order as shown by the broken line arrow. Return to compressor 2.

The cooling water whose temperature has been raised by cooling the engine 1 enters the radiator 9, where it is cooled by radiating heat to the outside air blown by the outdoor fan 7, and then urged by the cooling water circulation pump 10 to urge the engine. 1
Return to

During operation of the air conditioner, the room temperature detected by the room temperature sensor 21 and the set temperature set in the room temperature setting means 21 are input to the air conditioning load calculating means 22, and the air conditioning load is calculated based on them. It The calculated air conditioning load is input to the rotation speed control means 22, where the engine speed corresponding to the air conditioning load is determined, and this rotation speed is switched by the switching means 24.
Is output to the engine 1, and the engine 1 and the compressor 2 directly connected to the engine 1 are operated at a rotation speed corresponding to the air conditioning load.

When the engine 1 is started, the engine cooling water temperature detected by the cooling water temperature sensor 25 is the warm-up operating means 26.
, And the rotation speed corresponding to the cooling water temperature is determined. This rotation speed is output to the engine 1 via the switching means 24, and the engine 1 and the compressor 2 rotate at the rotation speed corresponding to the cooling water temperature. The above is the same as the conventional one.

A stagnation detecting means 27 for detecting whether or not the compressor 2 is in the refrigerant stagnation state when the engine 1 is started is provided. The stagnation detection means 27 is composed of a timer that accumulates the stop time of the compressor before starting, and the accumulated time is a predetermined time.
When it exceeds (for example, 6 hours), it can be determined that the compressor 2 is in the refrigerant stagnation state.

When the stagnation detecting means 27 detects the refrigerant stagnation state of the compressor 2 at the time of starting the engine, this output is input to the acclimation operation means 28, where the acclimation operation rotation speed of the compressor 2, that is, A predetermined rotation speed lower than the rotation speed determined by the warm-up operation means 26 is determined. This rotational speed is output to the engine 1 through the switching means 24, and the engine 1 and the compressor 2 rotate at the familiar operating rotational speed.

FIG. 2 shows a control flowchart. When the air conditioner is stopped, the engine 1 and the compressor 2
When the operation switch is turned on during the stop of, it is determined whether the compressor 2 is in the sleeping state. If not, engine 1
Is started and warmed up at the number of rotations determined by the warming-up operation means 26, and when the temperature of the cooling water rises to a predetermined temperature (for example, 60 ° C) by this warm-up operation, the rotation speed is controlled by the switching means 24. It is switched to the means 23, and thereafter, the operation is performed at the rotation speed corresponding to the air conditioning load determined by the means.

In that case, the engine 1 is started and operated at a predetermined rotation speed determined by the familiar operation control means 28, and when the cooling water temperature rises to a predetermined temperature (for example, 60 ° C.), the switching is performed. It is switched to the rotation speed control means 23 by the means 24, and thereafter, the operation is performed at the rotation speed corresponding to the air conditioning load determined by this.

Thus, the rotational speed of the engine 1 and the cooling water temperature change as shown by the broken line in FIG. 3 during the warm-up operation, but they change as shown by the solid line during the running-in operation, and the cooling water temperature becomes a predetermined value. After the temperature rises, the operation shifts to the operation corresponding to the air conditioning load indicated by the alternate long and short dash line.

[0021]

According to the present invention, when the compressor at start-up of the engine is in the refrigerant stagnation state, the engine is acclimated to operate at a predetermined rotation speed lower than the rotation speed determined by the warm-up operation means. As a result, even if the compressor is in a stagnation state, the refrigerant can be started without being damaged.

[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 diagram showing changes over time in engine speed and cooling water temperature at the time of engine startup in the above embodiment.

FIG. 4 is a diagram showing the relationship between engine speed and cooling water temperature during warm-up operation in a conventional engine-driven air conditioner.

[Explanation of symbols]

 1 Engine 2 Compressor 4 Outdoor Heat Exchanger 5 Throttle Mechanism 6 Indoor Heat Exchanger 9 Radiator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Minor Hanai No. 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Michio Yoneda No. 1 Takamichi, Iwatsuka-machi, Nakamura-ku, Nagoya (72) Inventor Tadahiro Kato, Asahi-cho 3-chome, Nishibiwajima-cho, Nishikasugai-gun, Aichi Prefecture Mitsubishi Heavy Industries, Ltd.

Claims (2)

[Claims] 1. A refrigeration cycle including a compressor driven by a water-cooled engine, an outdoor heat exchanger, a throttle mechanism, an indoor heat exchanger, etc., and an engine rotation for operating the engine at a rotation speed corresponding to an air conditioning load. An engine-driven air conditioner comprising a number control means and a warm-up operation means for operating the engine at a rotational speed determined according to the temperature of the cooling water at the time of starting, wherein the compressor of the compressor is activated when the engine is started. Detecting means for detecting the refrigerant stagnation state, familiar operating means for operating the engine at a predetermined rotation speed lower than the rotation speed determined by the warm-up operation means when the detection means detects the refrigerant stagnation status, and cooling water The engine has a switching means for switching to a rotation speed corresponding to the air conditioning load determined by the rotation speed control means when the temperature of the engine rises to the warm-up end temperature. Driven air conditioner. 2. The engine-driven air conditioner according to claim 1, wherein the detection means is composed of a timer that integrates the stop time of the compressor before starting.