JP2010255909A - Refrigerating device for land transportation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating device for land transportation for carrying out stable operation in various environmental conditions by using a high performance heat pump type. <P>SOLUTION: In the refrigerating device 1 for land transportation, an external heat exchanger 11 functioning as a condenser or an evaporator is equipped on a front wall 15 upper part of a van 7. It includes a duct 29 provided so as to cover one part of a front wall 15 in the front wall 15 of the van 7 and guiding engine exhaust air having passed through an engine 9 to a suction side of the external heat exchanger 11, and a damper 35 opening and closing a ventilation passage 31 in the duct 29. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus for land transportation.

A refrigeration system for land transportation is installed in a vehicle or the like that is installed in a cargo room (van) such as a truck, cools or heats the inside, and transports the loaded cargo at a desired temperature. .
The refrigeration equipment for land transportation includes a direct connection type that uses the output of a vehicle travel engine for driving a compressor for compressing refrigerant, and a sub-engine system that includes a dedicated drive source (such as an engine or an electric motor).

The refrigeration equipment for land transportation is, for example, frozen food that is cooled and transported to about −30 ° C., chilled food that is transported while maintaining about −1 to 5 ° C., and transported while maintaining the internal temperature of about 2 to 30 ° C. It is used in a wide set temperature range such as products to be used.
In order to cover such a wide set temperature range, it is necessary to provide both cooling and heating functions based on the relationship between the outside air temperature and the inside set temperature. In addition, since the land transportation refrigeration apparatus is used while moving, environmental conditions such as the outside air temperature vary greatly depending on changes in time, season and weather.

Conventionally, as an operation method for raising the temperature inside the warehouse in a refrigeration system for land transportation, as disclosed in Patent Document 1, high-temperature and high-pressure gas refrigerant (hot gas) discharged from a compressor is used for heat exchange outside the warehouse. A hot gas bypass heating method is generally used in which the heat exchanger is bypassed and circulated to the internal heat exchanger.
Also, as disclosed in Patent Document 2, in order to use the heat quantity of the exhaust gas of the engine, there has been proposed one that recovers this heat quantity with air passing through the engine and provides it to a refrigerant heater.

JP 2006-269805 A JP-A-6-341731

By the way, as shown in Patent Document 1, the hot gas bypass heating method has a small heating capacity and low energy efficiency because the hot gas changes the work of the compressor into heat.
When heat pump heating is generally used in an air conditioner, the heating capacity and energy efficiency problems can be solved.
However, the current situation is that heat pump heating, which is common in air conditioners, is not used as a refrigeration system for land transportation.
One reason for this was that it was not cost effective to provide expensive heat pump heating because there were few heating needs.

On the other hand, since the land transportation refrigeration apparatus attached to a traveling vehicle is used while moving, there is a problem that stable performance cannot be exhibited due to a large change in environmental conditions due to changes in time, season, and weather.
For example, when the external heat exchanger is used as an evaporator in winter, the heat exchange efficiency in the external heat exchanger decreases because the outside air temperature is low. Thereby, there exists a possibility that a heating capability falls and it becomes impossible to maintain the internal temperature at predetermined temperature.
In general, the external heat exchanger is arranged so that air can be easily sucked in consideration of cooling performance. When it is snowing, if the external heat exchanger is used as an evaporator, the snow blown into the external heat exchanger will land on the heat exchange part, and air will not pass even if the blower is operated. It will be in the state which does not show the function as an evaporator.
Although the defrost operation is performed when the external heat exchanger is frosted, it is difficult to remove the frost by the defrost due to the influence of the vehicle traveling wind.

  In view of such circumstances, an object of the present invention is to provide a refrigeration apparatus for land transport that can perform stable operation even under extreme environmental conditions using a high-performance heat pump system.

The present invention employs the following means in order to solve the above problems.
That is, the refrigeration apparatus for land transportation according to the present invention is a refrigeration apparatus for land transportation in which an external heat exchanger functioning as a condenser or an evaporator is provided on an upper part of a front wall of a cold storage, A duct that is provided on the front wall of the warehouse so as to cover a part of the front wall and guides the engine exhaust air that has passed through the vehicle running engine to the suction side of the external heat exchanger, and the ventilation in the duct And an opening / closing means for opening and closing the road.

According to the present invention, since the external heat exchanger functions as a condenser or an evaporator, a cooling operation can be performed when used as a condenser, and a heating operation can be performed when used as an evaporator. That is, since heat pump type cooling and heating can be performed, it is possible to perform air conditioning with high energy efficiency and high cooling capacity and heating capacity.
When the opening / closing means opens the ventilation path in the duct, the engine exhaust that passes through the vehicle engine and is discharged between the cabin and the cool box is sent to the duct attached to the front wall of the cool box. It is guided and supplied to the suction side of the external heat exchanger.

Since the engine exhaust air is warmed by the engine, it has a higher temperature than the outside air taken into the external heat exchanger. When the engine exhaust air is mixed with the outside air, the temperature of the air passing through the outside heat exchanger rises, so that it is possible to suppress a decrease in ability as an evaporator when the outside air temperature is low, such as in winter.
For example, in a directly connected refrigeration system for land transportation, when the vehicle is stopped and idling is being performed, the number of revolutions of the compressor is reduced, so that the heating capacity is reduced. Even in this case, since the heat recovery by the engine exhaust air can be performed, the amount of decrease in the heating capacity can be reduced.

If the opening / closing means closes the ventilation path in the duct, the engine exhaust air is not supplied to the external heat exchanger, so the outside air cannot be warmed by the engine exhaust air. For example, if the outside heat exchanger is used as a condenser when the outside air temperature is high, such as in summer, if the duct is closed by the opening and closing means, it can be prevented from being affected by engine exhaust air, so the capacity of the condenser is reduced. Can be suppressed.
In this way, it can be used as an evaporator when the outside air temperature is low, or as a condenser when the outside air temperature is high. The refrigeration system for land transportation can be stably operated because it can be reliably maintained.

  In the above invention, it is preferable that a panel for preventing traveling wind from directly entering the external heat exchanger is provided on the suction side of the external heat exchanger.

If it does in this way, driving | running | working wind will come in into the external heat exchanger so that it may wind around the panel. In other words, air is sucked into the external heat exchanger from a direction substantially orthogonal to the vehicle traveling direction. Therefore, the external heat exchanger is not easily affected by the ram pressure caused by the traveling wind.
For example, when an external heat exchanger is used as an evaporator during snowfall, the snow that blows into the external heat exchanger is not directly blown, so that it is possible to suppress snow from reaching the heat exchange section, The function can be maintained.
Further, since the traveling wind plays a function of guiding the engine exhaust air passing through the duct to the external heat exchanger, the engine exhaust air can be smoothly guided to the external heat exchanger.

In the said invention, it is suitable that the drain pan which accommodates a drain in the lower part of the said external heat exchanger is provided.
If it does in this way, when using an external heat exchanger as an evaporator, or when defrost operation is performed, the drain which generate | occur | produces can be collect | recovered to a drain pan, and can be discharged | emitted out of a vehicle collectively.

  In the above invention, the opening / closing means closes the ventilation path in the duct when the external heat exchanger functions as a condenser, and opens the ventilation path in the duct when functioning as an evaporator. It may be controlled to do so.

  In the above invention, the opening / closing means may be controlled to open the ventilation path in the duct when the outside heat exchanger functions as a condenser and the temperature is low outside air. Good.

  In the above invention, the opening / closing means may be controlled to close the ventilation path in the duct when the outside heat exchanger functions as an evaporator and the outside air temperature is high. Good.

According to the present invention, since heat pump type cooling and heating can be performed, energy efficiency is high, and air conditioning with high cooling capacity and heating capacity can be performed.
In addition, the front wall of the cool box is provided so as to cover the front wall, and opens and closes the duct that guides the engine exhaust that has passed through the vehicle engine to the suction side of the external heat exchanger, and the ventilation path in the duct Since the open / close means is provided, the refrigeration apparatus for land transportation can be stably operated, for example, the internal temperature can be reliably maintained at a predetermined temperature.

It is a fragmentary sectional view showing a schematic structure of a refrigeration apparatus for land transportation concerning one embodiment of the present invention.

Hereinafter, a refrigeration apparatus 1 for land transportation according to an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a partial cross-sectional view showing a schematic configuration of a refrigeration apparatus 1 for land transportation according to the present embodiment.
The truck 3 on which the refrigeration apparatus 1 for land transportation is installed is provided with a cabin 5 on which an occupant gets in and a van (cold storage) 7 loaded on the loading platform.
The cabin 5 is provided with an engine (vehicle traveling engine) 9 that drives the truck 3 to travel.

The refrigeration apparatus 1 for land transportation cools or heats the inside of the van 7 and maintains the loaded luggage at a desired temperature.
In the refrigeration apparatus 1 for land transportation, a compressor (not shown) that compresses refrigerant and discharges it as a high-pressure gas refrigerant, an external heat exchanger 11 installed outside the van 7, and installed inside the van 7. The internal heat exchanger 13 is provided.

  A heat pump type refrigerant circuit is formed so as to connect the compressor, the external heat exchanger 11 and the internal heat exchanger 13. The refrigerant circuit is configured such that the refrigerant flows from the compressor through the external heat exchanger 11 and the internal heat exchanger 13 to the compressor, and from the compressor through the internal heat exchanger 13 and the external heat exchanger 11. Thus, the flow returning to the compressor can be switched. By performing this switching, the external heat exchanger 11 functions as a condenser or as an evaporator.

When the external heat exchanger 11 functions as a condenser, the internal heat exchanger 13 functions as an evaporator, so the van 7 is cooled.
On the other hand, when the external heat exchanger 11 functions as an evaporator, the internal heat exchanger 13 functions as a condenser, so that the van 7 is heated.

As the compressor, for example, an open scroll compressor having a small size and high performance is used and driven by the engine 9. The format of the compressor 3 is not particularly limited.
Although the external heat exchanger 11 and the internal heat exchanger 13 are comprised by the parallel flow type heat exchanger of a rectangular parallelepiped shape, for example, it is not limited to this.

The internal heat exchanger 13 is installed in a space 17 formed at the upper end of the front wall 15 of the van 7 so as to protrude halfway forward (cabin 5 side).
The internal heat exchanger 13 is supplied with internal air in the van 7 by an internal fan 19. The internal fan 19 generates an airflow circulating through the indoor heat exchanger 13 in the van 7.

The external heat exchanger 11 is installed in front of the outer wall of the space 17 in which the internal heat exchanger 13 is accommodated, that is, on the outer upper portion of the front wall 15 of the van 7.
The external heat exchanger 11 is arrange | positioned so that a surface part may face the front. An outside fan 21 is installed on the rear side of the outside heat exchanger 11. When the outside fan 21 is operated, a flow of outside air flowing backward through the outside heat exchanger 11 is formed.

  A drain pan 23 that receives drain generated in the external heat exchanger 11 is provided in the lower part of the external heat exchanger 11. The drain collected by the drain pan 23 is discharged to the lower part of the track 3 by the drain exhaust pipe 25.

  A panel 27 is provided in front of the outside heat exchanger 11 on the suction side with a space therebetween. The panel 27 is a plate member having a substantially rectangular shape, and its peripheral edge is slightly bent backward. The panel 27 is mounted so as to be substantially parallel to the external heat exchanger 11 and completely cover the external heat exchanger 11.

A duct 29 is provided outside the front wall 15 of the van 7. The duct 29 is a long member having a U-shaped cross-sectional shape.
The duct 29 is arranged so as to extend from the lower end position of the front wall 15 to the lower position of the panel 27. The duct 29 has a U-shaped cross-sectional open end that is joined to the front wall 15 by, for example, screws. A ventilation path 31 is formed by the front wall 15 and the duct 29.

A cutout 33 that forms an opening facing the cabin 5 is provided at the lower end of the duct 29.
The cutout 33 is taken from the front surface of the truck 3, passes through the radiator and the engine 9, and faces the passage of engine exhaust air discharged between the cabin 3 and the van 7.
A damper (opening / closing means) 35 for opening and closing the ventilation path 31 is provided in the middle of the ventilation path 31.

The operation during operation of the refrigeration system 1 for land transportation configured as described above will be described.
First, the heating operation for increasing the temperature inside the van 7 will be described.
The refrigerant flows from the compressor so as to return to the compressor through the internal heat exchanger 13 and the external heat exchanger 11. The internal heat exchanger 13 functions as a condenser, and the external heat exchanger 11 functions as an evaporator.
When the compressor is driven to rotate, a low-pressure refrigerant gas is sucked and compressed to discharge a refrigerant gas that is a high-temperature and high-pressure superheated gas.

This refrigerant gas flows into the internal heat exchanger 13. The refrigerant gas flowing into the internal heat exchanger 13 is condensed and liquefied by heating the internal air circulating by the internal fan 19.
This liquid refrigerant is decompressed and supplied to the external heat exchanger 11. The refrigerant supplied to the external heat exchanger 11 cools the outside air ventilated by the external fan 21 and is evaporated and gasified.
At this time, since the panel 27 is installed in front of the external heat exchanger 11, the outside air as the traveling wind hits the panel 27 and flows into the external heat exchanger 11 so as to go around the peripheral edge of the panel 27. . In other words, outside air is sucked into the external heat exchanger 11 from a direction substantially orthogonal to the vehicle traveling direction. Therefore, the external heat exchanger 11 is hardly affected by the ram pressure caused by the traveling wind.

Thus, when the external heat exchanger 11 becomes difficult to be affected by the ram pressure caused by the traveling wind, for example, when the external heat exchanger 11 is used as an evaporator during snowfall, the external heat exchanger 11 Since the snow to be blown is not blown directly, it is possible to suppress the snow from reaching the heat exchanging portion and to maintain the function as an evaporator.
Further, since the running wind functions to guide the engine exhaust air passing through the ventilation path 31 to the external heat exchanger 11 as described later, the engine exhaust air can be smoothly guided to the external heat exchanger 11.

At this time, the damper 35 opens the ventilation path 31. Along with the movement of the outside fan 21 and the traveling wind, a negative pressure is generated in the lower rear part of the panel 27, so that an upward airflow is generated through the ventilation path 31. The engine exhaust wind that hits the notch 33 is guided by this air flow along with its own moving force, guided upward through the ventilation path 31, mixed with the outside air, and flows into the external heat exchanger 11.
Since the engine exhaust air is warmed by the engine 9, it has a temperature higher than the outside air taken into the external heat exchanger 11. When the engine exhaust air is mixed with the outside air, the temperature of the air passing through the outside heat exchanger 11 rises.

When the temperature of the outside air passing through the external heat exchanger 11 rises, the ability to evaporate the refrigerant can be improved. Thereby, the capability fall as an evaporator when the outside air temperature is low, such as in winter, can be suppressed.
When the temperature of the outside air is sufficiently high, the damper 35 may be closed so that the engine exhaust air is not supplied to the outside heat exchanger 11. That is, the heating capacity can be adjusted according to the environmental conditions.

  Further, in the direct-coupled refrigeration apparatus 1 for land transportation, when the truck 3 is stopped and idling operation is performed, the rotational speed of the compressor is decreased, so that the heating capacity is decreased. Even in this case, since the heat recovery by the engine exhaust air can be performed, the amount of decrease in the heating capacity can be reduced.

When the external heat exchanger 11 is used as an evaporator, or when a defrost operation is performed, since the outside air loses heat, moisture may condense and drainage may occur. The generated drain is collected in the drain pan 23 and discharged to the outside through the drain vent pipe 25.
The evaporated gasified refrigerant is again sucked into the compressor, and the heating operation is performed by repeating the same cycle.

Next, a cooling operation for maintaining the inside of the van 7 at a low temperature will be described.
The refrigerant flows from the compressor through the external heat exchanger 11 and the internal heat exchanger 13 so as to return to the compressor. The external heat exchanger 11 functions as a condenser, and the internal heat exchanger 13 functions as an evaporator.
When the compressor is driven to rotate, a low-pressure refrigerant gas is sucked and compressed to discharge a refrigerant gas that is a high-temperature and high-pressure superheated gas.

This refrigerant gas flows into the external heat exchanger 11. The refrigerant gas flowing into the external heat exchanger 11 is condensed and liquefied by exchanging heat with the external air ventilated by the external fan 21.
At this time, the damper 35 closes the ventilation path 31. This is because when functioning as a condenser, the lower the outside air temperature, the greater the ability to condense and liquefy the refrigerant.
If the temperature of the outside air is sufficiently low, the damper 35 may be opened to supply the engine exhaust air to the outside heat exchanger 11. That is, the cooling capacity can be adjusted according to the environmental conditions.
Thus, since the ventilation path 31 can be closed by the damper 35, for example, when the outside air temperature is high such as in summer, it is possible to prevent the engine exhaust from being affected. Thereby, the capability fall as a capacitor | condenser can be suppressed.

The liquid refrigerant is decompressed by a decompression valve (not shown) and supplied to the internal heat exchanger 13. The refrigerant supplied to the in-compartment heat exchanger 13 cools the circulating air to evaporate.
The inside of the van 7 is cooled to a predetermined temperature by this cooling air. The evaporated gasified refrigerant is again sucked into the compressor, and the cooling operation is performed by repeating the same cycle.

In this way, since the heat pump type cooling operation and heating operation can be performed, air conditioning with high energy efficiency and high cooling capacity and heating capacity can be performed.
In addition, it can be used as an evaporator when the outside air temperature is low, or used as a condenser when the outside air temperature is high, so that a decrease in capacity as a heat exchanger can be suppressed even under extreme environmental conditions. The refrigeration apparatus 1 for land transportation can be stably operated because it can be maintained.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably.

1 Refrigeration equipment for land transport 7 Van 9 Engine 11 External heat exchanger 15 Front wall 23 Drain pan 27 Panel 29 Duct 31 Ventilation path 35 Damper

Claims (6)

A refrigeration system for land transportation in which an external heat exchanger that functions as a condenser or an evaporator is provided on the upper part of the front wall of the cold storage,
A duct that is provided on the front wall of the cold storage so as to cover a part of the front wall and guides engine exhaust air that has passed through the vehicle running engine to the suction side of the external heat exchanger;
A refrigeration apparatus for land transportation, comprising: opening and closing means for opening and closing a ventilation path in the duct.   The refrigeration apparatus for land transportation according to claim 1, wherein a panel for preventing traveling wind from directly entering the external heat exchanger is provided on the suction side of the external heat exchanger.   The refrigeration apparatus for land transportation according to claim 1 or 2, wherein a drain pan for storing drain is provided in a lower part of the external heat exchanger.   The opening / closing means is controlled to close the ventilation path in the duct when the external heat exchanger functions as a condenser, and to open the ventilation path in the duct when functioning as an evaporator. The refrigeration apparatus for land transportation according to any one of claims 1 to 3, wherein the refrigeration apparatus is for land transportation.   2. The opening / closing means is controlled so as to open a ventilation path in the duct when the outside heat exchanger functions as a condenser and has a low outside air temperature. The refrigeration apparatus for land transportation according to any one of claims 1 to 4. 2. The opening / closing means is controlled so that the outside heat exchanger functions as an evaporator and closes the ventilation path in the duct when the outside air temperature is high. The refrigeration apparatus for land transportation according to any one of claims 1 to 4.

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