JPS6296129A - Air conditioner for diesel locomotive - Google Patents

Abstract

PURPOSE:To enable the air cooling and heating to be continuously operated in the titled air conditioner of a heat pump type by arranging an external heat exchanger to a cooling wind ventilator of a radiator thereby changing the direction of ventilation for blowing air with a radiator cooling fan operated. CONSTITUTION:When an air cooling is operated, the radiation of heat is effected by an external heat exchanger 4a as shown by a solid line, besides, the air cooling is effected by cooling air in a cabin through an indoor heat exchanger 3. In this case, air is ventilated to the direction shown by the solid line with a radiator cooling fan operated. With this, the effect by exhaust temperature from a radiator 12 against the indoor heat exchanger 4a is removed. And radiation and ventilation are effected as shown by a dotted line for heating. Cooling and heating can be continuously operated smoothly by this constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an air conditioner for a diesel locomotive, and particularly to an air conditioner for a diesel locomotive suitable for use in a heat pump system.

[Background of the invention]

As a conventional beat pump type air conditioner,
This method is known from, for example, Japanese Patent No. 6-19552. To explain this configuration with reference to FIG. 5, the refrigerant pressurized by the compressor II is passed through the four-way valve 2, and during cooling operation, the solid line arrow,
During heating operation, heat flows as shown by the dotted arrows. The configuration will be explained according to the refrigerant flow path during cooling operation. The refrigerant that exits the four-way valve 2 is first cooled by the outdoor heat exchanger 4, passes through the check valve 9 attached to the heating expansion valve 8, passes through the receiver 6, and is depressurized by the cooling expansion valve 7 to generate indoor heat. is led to exchanger 3. In addition, the cooling expansion valve 7 is also provided with a heat check valve 9. The refrigerant that has performed a cooling action by exchanging heat with indoor air in the indoor heat exchanger 3 is sent into the accumulator 5 via the four-way valve 2, where the liquid refrigerant is separated and only the gas refrigerant is sent to the compressor 1. is pressurized again and circulated in the same manner as above. In addition, in the case of decooling operation, the four-way valve 2 is switched to circulate the refrigerant in the opposite direction in the circulation circuit. In such a configuration, since the outdoor heat exchanger 4 performs the evaporation action of low-temperature, low-pressure refrigerant gas during heating operation in winter, frost forms on the surface of the outdoor heat exchanger 4 when the outside air temperature reaches about O'C. However, it has the problem of reducing air conditioning performance, which is a particular problem in hot and cold regions. By the way, even if such a heat pump type air conditioner y is installed in a diesel locomotive, there is a problem as mentioned above, and there is a drawback that the air conditioner cannot be operated continuously.

1. OBJECTS OF THE INVENTION An object of the present invention is to provide an air conditioning system for a diesel locomotive that can perform continuous cooling and heating operation without any trouble.

[Summary of the invention]

The present invention provides an air conditioner installed in a diesel locomotive, in which an outdoor heat exchanger is placed in an engine cooling air path, and cooling exhaust heat of the engine is used to increase the heat exchange air temperature during heating operation of the outdoor heat exchanger. It is characterized by increasing the

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an air conditioner according to the present invention will be described below with reference to FIGS. 1 to 4. In the figure, the same reference numerals as in the conventional example indicate the same members. Ia is a compressor driven by a power engine 11 provided in the diesel locomotive 10. The hill is a radiator for cooling the power engine 11. Reference numeral 13 denotes a radiator cooling fan that guides cooling air to the radiator 12, and the direction of the cooling air can be changed arbitrarily. Reference numeral 4a denotes an outdoor heat exchanger arranged near the radiator 12 at a position corresponding to the ventilation path for cooling air. 14 is a cold/warm expansion valve installed between the indoor heat exchanger 3 and the outdoor heat exchanger 4a.

In such a configuration, during cooling operation, the outdoor heat exchanger 4a radiates heat as shown by the solid arrow in FIG. 4, and the indoor heat exchanger 3 cools the indoor air to perform cooling. At this time, since the outdoor heat exchanger 4a radiates heat as described above, it is desirable that the temperature of the outside air to which heat is exchanged is as low as possible. Therefore, the radiator cooling fan 13 is operated so that the outside air supplied to the outdoor heat exchanger 4a and the radiator 12 is ventilated in the direction shown by the solid line arrow in FIG. Therefore, the outdoor heat exchanger 4a is not adversely affected by the exhaust heat from the radiator.

Also, during heating operation, as shown by the dotted line arrow in Figure 4 (
The outdoor heat exchanger 4a pumps up heat, and the indoor heat exchanger 3 radiates heat for heating. At this time,
Since the outdoor heat exchanger 4a pumps up heat, if the supplied outside air temperature is low, frost will form as described above. Therefore,
The supply of outside air to the outdoor heat exchanger 4a and the radiator hill is as follows:
Ventilation is carried out in the direction shown at the middle point in FIG. 3, which is opposite to that during cooling.

That is, the air is ventilated to the outdoor heat exchanger 4a through the radiator 12, and the exhaust heat from the radiator 12 raises the temperature of the outside air, which is then supplied to the outdoor heat exchanger 4a. However, since the outside air supplied to the outdoor heat exchanger 4a during heating is usually at a predetermined temperature or higher, frost formation on the outdoor heat exchanger 4a can be prevented.

According to such a configuration, during cooling operation, air conditioning can be performed in exactly the same manner as in normal operating conditions, while during heating operation, the outside air supplied to the outdoor heat exchanger 4a is warmed by the exhaust heat from the radiator. Therefore, there is no frost formation on the outdoor heat exchanger 4a, and continuous operation can be performed. Further, as mentioned above, since frost does not form on the outdoor heat exchanger 4a, there is no need to perform unpleasant and complicated operations such as defrosting operation (comfort and operability can be improved.Furthermore, in the above configuration, , it does not have a particularly complicated structure, and there are no particular problems in manufacturing.

It can be easily installed on existing locomotives.

〔Effect of the invention〕

As explained above, according to the present invention, since frost formation on the outdoor heat exchanger can be prevented, continuous cooling/heating operations can be carried out without difficulty.

[Brief explanation of drawings]

Figure ff11 is a plan view of a diesel locomotive showing the equipment arrangement in an embodiment of the air conditioner according to the present invention, and Figure 2 is @
Fig. 1 is a side view, Fig. 3 is a cross-sectional view of the radiator and outdoor heat exchanger part of Fig. 1, Fig. 4 is a circuit diagram showing the refrigeration cycle in the air conditioner shown in Fig. i1, and Fig. 5 is a conventional It is a circuit diagram showing a refrigeration cycle in an air conditioner. 1a... Compressor, 2... Four-way valve, 3.
...Indoor heat exchanger, 4a...Outdoor heat exchanger, 10...Diesel locomotive, Shi...
・Radiator, 13...Radiator cooling fan K]h

Claims (1)

[Claims] 1. In heat pump type air conditioners installed in diesel locomotives, the outdoor heat exchanger is placed in the cooling air ventilator of the radiator, and the direction of the radiator cooling fan that blows air into the radiator is switched to supply cooling air. An air conditioning system for a diesel locomotive, characterized by: