JP7297560B2 - Unit warming system - Google Patents

Description

The present invention relates to a system for warming up a unit such as an engine.

A vehicle equipped with an engine is provided with an engine cooling system for cooling the engine.

In the engine cooling system, cooling water flows through the engine due to the operation of the water pump. A flow path of cooling water flowing out from the engine branches into a branched passage passing through a heater core for air conditioning in the passenger compartment and a branched passage passing through a radiator. These branch paths join at a thermostat valve provided upstream of the water pump. The thermostat valve prevents the cooling water from flowing from the radiator to the water pump when the temperature of the cooling water is below a predetermined temperature. Thereby, when the temperature of the cooling water is equal to or lower than the predetermined temperature, the cooling water circulates between the engine and the heater core without flowing through the radiator. As the cooling water flows through the heater core, heat is exchanged between the cooling water and the heater core to heat the heater core. When the temperature of the cooling water exceeds a predetermined temperature, the thermostat valve allows the cooling water to flow from the radiator to the water pump, and the cooling water flows through the heater core and the radiator. As the cooling water flows through the radiator, heat is exchanged between the cooling water and the radiator to cool the cooling water.

When the engine is cold-started, the vaporization of the fuel is poor, and the viscosity of the engine oil is high, resulting in large engine friction, resulting in low fuel consumption. Moreover, since the cooling water temperature is low, the effectiveness of the air conditioning heater is poor. Therefore, it is preferable to quickly complete warm-up of the engine when the engine is cold-started.

Therefore, when the engine is cold-started, the refrigeration cycle is operated to exchange heat between the high-temperature, high-pressure refrigerant pumped from the compressor and the cooling water in the engine cooling system, thereby increasing the temperature of the cooling water. has been proposed (see, for example, Patent Document 1).

JP-A-2004-143961

However, the cooling water in the engine cooling system is difficult to warm, and its temperature rises slowly. Therefore, in the configuration according to the conventional proposal, it takes time to warm up the engine.

SUMMARY OF THE INVENTION An object of the present invention is to provide a unit warm-up system capable of rapidly raising the temperature of a unit such as an engine.

To achieve the above object, a unit warming system according to the present invention comprises an air-conditioning refrigeration cycle circuit including an evaporator to which refrigerant compressed by a refrigerant compressor is liquefied by condensation and expansion, and supplied by the refrigerant compressor. a warm-up refrigeration cycle circuit including a first heat exchanger to which compressed refrigerant is supplied and a second heat exchanger to which refrigerant that has passed through the first heat exchanger is supplied; a radiator and the second heat exchanger; and a cooling water circulation path for circulating cooling water between the first heat exchanger and the oil sealed in the unit by operating the refrigerant compressor when the unit is cold. and heat exchange between the refrigerant and the cooling water in the second heat exchanger.

According to this configuration, when the unit is cold and the unit is cold, the refrigerant is compressed by the operation of the refrigerant compressor. The heat exchanger exchanges heat between the high-temperature and high-pressure refrigerant and the oil enclosed in the unit. This increases the temperature of the oil in the unit. Since the oil has a smaller specific gravity and specific heat than the cooling water, the oil warms up more easily than the cooling water. Therefore, the temperature of the unit can be rapidly increased compared to a configuration in which the cooling water is warmed by the refrigerant and the unit is warmed by the cooling water.

In addition, since the refrigerant compressor is used both for the air-conditioning refrigeration cycle circuit and for the warming-up refrigeration cycle circuit, compared to a configuration in which separate refrigerant compressors are provided for the air-conditioning refrigeration cycle circuit and the warming-up refrigeration cycle circuit. , the number of parts can be reduced, and the cost can be reduced.

The radiator is also used as a unit cooling system for cooling the unit with cooling water. It is preferable that the cooling water absorbs heat when the unit is cold, and releases heat from the cooling water after the unit is warmed up. With this configuration, there is no need to additionally provide a radiator for absorbing heat into the cooling water when the engine is cold, in addition to the radiator for releasing heat from the cooling water, so the number of parts can be reduced and the cost can be reduced.

ADVANTAGE OF THE INVENTION According to this invention, a unit can be heated up rapidly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically showing the configuration of an engine warm-up system according to an embodiment of the present invention, and also showing flows of A/C refrigerant and cooling water when the engine is cold; FIG. 2 is a diagram schematically showing the configuration of an engine warm-up system, and also shows the flows of A/C refrigerant and cooling water during normal operation (after completion of warm-up).

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<System configuration>
1 and 2 are diagrams schematically showing the configuration of an engine warm-up system 1 according to one embodiment of the present invention.

The engine warm-up system 1 is a system that is applied to a vehicle equipped with an engine (E/G) 2 as a drive source, and aims to accelerate the temperature rise of the engine 2 (early warm-up). It does not matter whether the engine 2 is a gasoline engine or a diesel engine. Further, the vehicle may be a conventional engine vehicle as long as it is equipped with the engine 2, or it may be a hybrid vehicle further equipped with a motor as a drive source for running.

The engine warm-up system 1 utilizes an air-conditioning refrigeration cycle circuit 3 and an engine cooling system 4 conventionally mounted on a vehicle.

The air-conditioning refrigeration cycle circuit 3 includes a refrigerant compressor 11 , a condenser 12 , an expansion valve (expan) 13 and an evaporator 14 . The refrigerant compressor 11, the condenser 12, the expansion valve 13 and the evaporator 14 are interposed in a refrigerant circuit 15 through which the A/C refrigerant circulates.

The engine cooling system 4 is a cooling system that cools the engine 2 with cooling water. A water jacket is formed in the engine 2 . The water jacket is a flow path through which cooling water flows, and has a water jacket inlet 21 and a water jacket outlet 22 for cooling water.

Engine cooling system 4 includes water pump 23 , radiator 24 and thermostat valve 25 .

The water pump 23 is a mechanical water pump driven by the power of the engine 2 . Radiator 24 has a first radiator inlet 26 and a first radiator outlet 27 . A radiator channel is formed in the radiator 24, and the first radiator inlet 26 and the first radiator outlet 27 communicate with each other through the radiator channel.

One end of an inflow passage 31 is connected to the water jacket inlet 21 of the water jacket. The other end of the inflow passage 31 is connected to the thermostat valve 25 . The water pump 23 is interposed in the middle of the inflow passage 31 . On the other hand, the water jacket outlet 22 is connected to an outflow passage 34 that branches into a first branch passage 32 and a second branch passage 33 on the way. The first branch 32 is connected to the first radiator inlet 26 of the radiator 24 . One end of a connection path 35 is connected to the first radiator outlet 27 of the radiator 24 . The other end of the connection path 35 is connected to the thermostat valve 25 . The second branch 33 is connected to the thermostat valve 25 via the heater core 36 .

The engine cooling system 4 also includes a radiator fan 37 . The radiator fan 37 is arranged to face the radiator 24 in its rotational axis direction. Therefore, when the radiator fan 37 operates, air blown from outside the vehicle hits the radiator 24 .

The engine warm-up system 1 is provided with a warm-up refrigeration cycle circuit 5 and an endothermic system 6 in addition to the air-conditioning refrigeration cycle circuit 3 and the engine cooling system 4 .

The warm-up refrigeration cycle circuit 5 includes a refrigerant compressor 11 , an oil warmer 41 , an expansion valve 42 and a heat exchanger 43 . The refrigerant compressor 11 is included in both the air-conditioning refrigeration cycle circuit 3 and the warm-up refrigeration cycle circuit 5, and is used in both. The oil warmer 41 , the expansion valve 42 and the heat exchanger 43 are interposed in the refrigerant flow path 44 . One end of the refrigerant flow path 44 is connected by a three-way valve 45 to a portion of the refrigerant circulation path 15 that connects the refrigerant compressor 11 and the condenser 12 . The other end of the refrigerant flow path 44 is connected by a three-way valve 46 to a portion of the refrigerant circulation path 15 that connects the refrigerant compressor 11 and the evaporator 14 .

The heat absorption system 6 includes a radiator 24 , an electric water pump (EWP) 51 and an on-off valve 52 . The radiator 24 is included in both the engine cooling system 4 and the heat absorption system 6 and is used for both. The radiator 24 is formed with a second radiator inlet 53 and a second radiator outlet 54 separately from the first radiator inlet 26 and the first radiator outlet 27 . The second radiator inlet 53 and the second radiator outlet 54 are in communication with each other via a radiator channel inside the radiator 24 .

One end of a cooling water circulation path 55 is connected to the second radiator inlet 53 , and the other end of the cooling water circulation path 55 is connected to the second radiator outlet 54 . The cooling water circulation path 55 passes through the heat exchanger 43 on the way. The electric water pump 51 is interposed between the heat exchanger 43 and the second radiator outlet 54 . The open/close valve 52 is interposed between the electric water pump 51 and the second radiator outlet 54 .

<Operation when cold>
Refrigerant compressor 11 is driven by the power of engine 2, for example. When the refrigerant compressor 11 is driven, the A/C refrigerant is compressed by the refrigerant compressor 11 , and the compression causes the A/C refrigerant to be pressurized and heated to a high temperature and high pressure.

When the engine 2 is cold, as indicated by the arrows in FIG. be done. Therefore, the high-temperature and high-pressure A/C refrigerant is supplied to the oil warmer 41 . In the oil warmer 41 , heat is exchanged between the high-temperature and high-pressure A/C refrigerant and the engine oil enclosed in the engine 2 .

This heat exchange raises the temperature of the engine oil, which in turn raises the temperature of the engine 2 . Since the power of the engine 2 drives the water pump 23 , the coolant flows through the inflow passage 31 toward the engine 2 . The cooling water flows into the water jacket from the water jacket inlet 21 of the engine 2 , flows through the water jacket, and flows out from the water jacket outlet 22 to the outflow passage 34 .

Thermostat valve 25 blocks the flow of cooling water from radiator 24 to water pump 23 when the temperature of the cooling water is below a predetermined temperature. Accordingly, when the temperature of the cooling water is equal to or lower than the predetermined temperature, the cooling water circulates between the engine 2 and the heater core 36 without flowing through the radiator 24 . As the cooling water flows through the heater core 36, heat is exchanged between the cooling water and the heater core 36, and the temperature of the heater core 36 rises.

On the other hand, the A/C refrigerant is cooled, and the liquefaction of the A/C refrigerant progresses. A/C refrigerant is supplied from the oil warmer 41 to the expansion valve 42 via a receiver (not shown). In the receiver, liquefied A/C refrigerant and non-liquefied A/C refrigerant are separated. Only the liquefied refrigerant is supplied to the expansion valve 42 . Then, the liquefied A/C refrigerant is supplied from the expansion valve 42 to the heat exchanger 43 .

Also, when the engine is cold, the electric water pump 51 is driven and the open/close valve 52 is opened. Thereby, the cooling water circulates through the cooling water circulation path 55 between the radiator 24 and the heat exchanger 43 . The heat exchanger 43 exchanges heat between the A/C refrigerant and cooling water. That is, the liquefied A/C refrigerant is decompressed by the expansion valve 42 and takes heat from the heat exchanger 43 to evaporate again, the heat exchanger 43 takes heat from the cooling water, and the cooling water is cooled. As the cooled cooling water flows through the radiator flow path in the radiator 24, heat is exchanged between the cooling water and the radiator 24, and the cooling water absorbs heat from the radiator 24 to raise its temperature. At this time, the radiator fan 37 is driven and the air blown from the outside of the vehicle hits the radiator 24, thereby promoting heat exchange between the cooling water and the radiator 24. FIG.

<Normal operation>
When the temperature of the engine 2 rises and the warm-up of the engine 2 is completed, as indicated by the arrow in FIG. The three-way valves 45, 46 are switched. Therefore, the high-temperature and high-pressure A/C refrigerant is supplied to the condenser 12 . In the condenser 12, the high-temperature and high-pressure A/C refrigerant is cooled by air blown from the condenser fan, and the A/C refrigerant is liquefied. A/C refrigerant is supplied from condenser 12 to expansion valve 13 via a receiver (not shown). In the receiver, liquefied A/C refrigerant and non-liquefied A/C refrigerant are separated. Only the liquefied refrigerant is supplied to the expansion valve 13 . Then, the liquefied refrigerant is injected from the expansion valve 13 to the evaporator 14 . At this time, the liquefied refrigerant takes heat from the evaporator 14 and evaporates again, thereby cooling the evaporator 14 .

When the engine 2 is completely warmed up, the electric water pump 51 is stopped and the open/close valve 52 is closed.

When the temperature of the cooling water exceeds a predetermined temperature, the thermostat valve 25 allows the cooling water to flow from the radiator 24 to the water pump 23, and the cooling water flows through both the radiator 24 and the heater core 36. As the cooling water flows through the radiator 24, heat is exchanged between the cooling water and the radiator 24, and the cooling water radiates heat to the radiator 24 to lower its temperature.

<Effect>
As described above, when the engine 2 is cold, the A/C refrigerant is compressed by the operation of the refrigerant compressor 11, and the high-temperature and high-pressure A/C refrigerant pressurized and heated by the compression is supplied to the oil warmer 41. Then, the oil warmer 41 performs heat exchange between the high-temperature and high-pressure A/C refrigerant and the engine oil enclosed in the engine 2 . This increases the temperature of the engine oil. Since engine oil has a smaller specific gravity and specific heat than cooling water, it warms more easily than cooling water. Therefore, in this engine warm-up system 1, the temperature of the engine 2 can be rapidly raised compared to a configuration in which the cooling water is warmed by the A/C refrigerant and the engine 2 is warmed by the cooling water. In addition, since the viscosity of the engine oil is rapidly lowered, it is possible to prevent a state in which the friction of the engine 2 is large from continuing for a long time, and to improve fuel efficiency by reducing friction loss.

Furthermore, since the warm-up of the engine 2 can be completed early, the temperature of the heater core 36 can be quickly raised. As a result, it is possible to suppress the continuation of the state in which the air-conditioning heater is ineffective, and it is possible to improve the comfort of the air-conditioning in the passenger compartment by improving the heater performance.

Since the refrigerant compressor 11 is used both for the air-conditioning refrigeration cycle circuit 3 and for the warming-up refrigeration cycle circuit 5, the refrigerant compressor 11 is separately used for the air-conditioning refrigeration cycle circuit 3 and the warming-up refrigeration cycle circuit 5. The number of parts can be reduced and the cost can be reduced compared to the configuration in which they are provided.

The radiator 24 also serves as an engine 2 cooling system that cools the engine 2 with cooling water, and causes the cooling water to absorb heat when the engine is cold, and releases heat from the cooling water after the engine 2 is warmed up. With this configuration, apart from the radiator 24 for radiating heat from the cooling water, there is no need to additionally provide a radiator for absorbing heat from the cooling water when the machine is cold. .

By reducing the number of parts of the engine warm-up system 1, the mountability of the engine warm-up system 1 in the engine compartment of the vehicle is improved.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, in the above-described embodiments, the engine 2 was taken up as an example of the unit. However, the present invention is not limited to a system for warming up the engine 2, but may be applied to a system for warming up a unit in which oil is enclosed, for example a system for warming up a transaxle. The present invention can be applied.

In addition, various design changes can be made to the above configuration within the scope of the matters described in the claims.

1: Engine warm-up system (unit warm-up system)
2: Engine (unit)
3: Air conditioning refrigeration cycle circuit 5: Warming refrigeration cycle circuit 6: Endothermic system 11: Refrigerant compressor 14: Evaporator 24: Radiator 41: Oil warmer (first heat exchanger)
43: Heat exchanger (second heat exchanger)
55: Cooling water circulation path

Claims (1)

an air conditioning refrigeration cycle circuit comprising an evaporator to which refrigerant compressed by a refrigerant compressor is liquefied by condensation and expansion and supplied;
a unit cooling system for cooling the unit with cooling water;
a warm-up refrigeration cycle circuit comprising a first heat exchanger supplied with refrigerant compressed by the refrigerant compressor and a second heat exchanger supplied with refrigerant having passed through the first heat exchanger;
a radiator and an endothermic system including a cooling water circuit that circulates cooling water between the radiator and the second heat exchanger;
the radiator is included in both the unit cooling system and the heat absorption system and is used for both;
When the unit is cold, the refrigerant compressor is operated to cause heat exchange between the refrigerant and the oil enclosed in the unit in the first heat exchanger, and the refrigerant and the oil in the second heat exchanger . Exchanging heat with the cooling water circulating in the cooling water circulation path , the cooling water absorbs heat from the radiator and rises in temperature,
A unit warm-up system in which, after the unit is warmed up, cooling water does not circulate in the cooling water circulation path but flows through the unit cooling system so that the cooling water dissipates heat to the radiator and lowers the temperature.

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