JP2008070068A - Refrigeration device for refrigerator car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower an air temperature in an inside of a refrigerator to the utmost, even under the stop of a traveling engine. <P>SOLUTION: An electric fan 3 is started to blow air when a door 7 is changed from an opening state to a closed state, when a detection value detected by a refrigerator inside temperature sensor 4 is higher than a detection value detected by an evaporator diffusion air temperature sensor 5, and when the detection value detected by the evaporator diffusion air temperature sensor 5 is lower than zero, even when an ignition switch IG is turned off to stop the traveling engine. The electric fan 3 blows the air toward an evaporator 2, cold air is thereby blown out of the evaporator 2 by a heat capacity of the evaporator 2, and the inside of the refrigerator 1 is cooled by the cold air. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus for a refrigerator car that cools the inside of a freezer by an evaporator.

Conventionally, in a refrigeration apparatus for a freezer used for delivery of frozen foods, a cooling unit in which an evaporator and a blower are assembled together is disposed at an upper part in a freezer to evaporate refrigerant circulated from a compressor. In some cases, the air is blown toward the evaporator by a blower and the cold air from the evaporator is circulated in the freezer to maintain the inside of the freezer at a low target temperature such as −18 ° C. (for example, Patent Documents) 1).
JP 2003-341515 A

  However, in the above-described refrigeration apparatus for a refrigerator car, even if the temperature inside the freezer is set to a predetermined low temperature, the engine is stopped and the compressor is stopped during delivery. For this reason, when the door is opened for loading and unloading the load while the engine is stopped, the outside air enters the freezer and the internal temperature rises. Therefore, when the frozen food is put in the freezer, the freshness of the frozen food falls.

  In view of the above points, an object of the present invention is to provide a refrigeration apparatus for a freezing vehicle in which the air temperature in the freezer is kept as low as possible even while the on-vehicle engine is stopped.

  The present invention has been made by paying attention to the fact that the inside of the freezer can be cooled using the heat capacity of the evaporator even if the on-vehicle engine is stopped and the compressor is stopped.

  Specifically, according to the present invention, when the door determination unit determines that the door of the freezer has changed from the open state to the closed state while the vehicle-mounted engine is stopped, the temperature detected by the internal air temperature sensor is the evaporator temperature sensor. If the temperature determining means determines that the detected temperature is higher than the detected temperature, and the evaporator temperature determining means determines that the detected temperature of the evaporator temperature sensor is lower than zero degrees, the blow start control means for starting the blower of the blower And.

  As a result, after the door changes from the open state to the closed state while the in-vehicle engine is stopped, the blower blows when the internal air temperature is higher than the evaporator temperature and the evaporator temperature is lower than zero degrees. When started, cold air can be blown from the evaporator due to the heat capacity of the evaporator. Therefore, the air temperature in the freezer can be kept as low as possible by the cold air from the evaporator.

  1 and 2 show a schematic configuration of an embodiment of a refrigeration vehicle to which a refrigeration apparatus according to the present invention is applied.

  As shown in FIG. 1, the freezer of the present embodiment is provided with a freezer 1 for storing a load such as frozen food, and the loader is loaded or unloaded behind the freezer 1. A door 7 for opening and closing the rear opening 6 is provided.

  An evaporator 2 is disposed on the upper side in the freezer 1. The evaporator 2 includes a compressor 11, a condenser 12, a liquid receiver 14, an expansion valve 15, and a gas-liquid separator as shown in FIG. 2. 16 constitutes the refrigeration cycle apparatus R.

  The compressor 11 is driven by the traveling engine via the electromagnetic clutch 11a, and sucks, compresses, and discharges the refrigerant. The condenser 12 cools the high-temperature / high-pressure refrigerant discharged from the compressor 11 by the air blown from the electric blower 13. The liquid receiver 14 separates the refrigerant flowing out of the capacitor 12 into a liquid phase refrigerant and a gas phase refrigerant. The expansion valve 15 depressurizes the liquid-phase refrigerant that passes through the liquid receiver 14.

  The evaporator 2 evaporates the refrigerant from the expansion valve 15 and cools the blown air from the electric blower 3. The electric blower 3 is provided in the freezer 1 and blows air toward the evaporator 2. The gas-liquid separator 16 separates the refrigerant flowing out of the evaporator 2 into a liquid phase refrigerant and a gas phase refrigerant, and returns the gas phase refrigerant to the suction side of the compressor 11.

  Further, a bypass passage 17a is provided between the refrigerant outlet side of the compressor 11 and the refrigerant inlet side of the evaporator 2, and a defrosting electromagnetic valve 17a is arranged in the middle of the bypass passage 17a.

  In addition, the refrigeration vehicle according to the present embodiment is provided with a control device 10, and the control device 10 includes a microcomputer, a memory, a peripheral circuit, and the like. The control device 10 controls the electromagnetic clutch 11 a and the electric blowers 3 and 13 based on the output signal of the internal temperature sensor 4, the output signal of the evaporator blown air temperature sensor 5, and the output signal of the door switch 9.

  The internal temperature sensor 4 is a sensor that detects the air temperature in the freezer 1, and the evaporator blown air temperature sensor 5 is a sensor that detects the temperature of air blown from the evaporator 2. The door switch 9 is a switch that detects the opening / closing of the door 7 for loading / unloading the cargo in the freezer 1 and is a normally open switch (or normally closed) that is turned on / off when the door 7 is opened → closed. Type switch). The electric blowers 3 and 13 are configured by an electric motor that is driven by being supplied with power from the in-vehicle battery B, and an impeller that is driven by the electric motor to generate air blowing.

  Next, the operation of the control device 10 of the present embodiment will be described.

  First, when the ignition switch IG is on, the control device 10 uses the electromagnetic clutch 11a and the electric blower to maintain the air temperature in the freezer 1 at a target temperature (for example, −10 ° C. to −20 ° C.). Refrigeration control for controlling 3 and 13 is executed. Since this refrigeration control is well known, description thereof is omitted.

  Further, when the ignition switch IG is turned off and the traveling engine is stopped, the compressor 11 is stopped. At this time, the control apparatus 10 performs the cold insulation fan control for keeping the air temperature in the freezer 1 as low as possible. Below, cold storage fan control is demonstrated.

  First, in step S100, based on the output signal of the door switch 9, it is determined whether or not the door 7 of the freezer 1 has changed from the open state to the closed state. When it determines with the door 7 having changed from the open state to the closed state, it determines with YES and transfers to step S110 and detects the detected value of the temperature sensor 4 in a store | warehouse | chamber. In the next step S120, the detected value of the evaporator blown air temperature sensor 5 is detected.

  In the next step S130, it is determined whether or not the detected value of the internal temperature sensor 4 is higher than the detected value of the evaporator blown air temperature sensor 5. When the detected value of the internal temperature sensor 4 is higher than the detected value of the evaporator blown air temperature sensor 5, it is determined as YES and the process proceeds to step S140. It is determined whether the detected value of the evaporator blown air temperature sensor 5 is lower than zero degrees. When the detected value of the evaporator blown air temperature sensor 5 is lower than zero degree, the blower of the electric blower 3 is started. Along with this, the electric blower 3 blows air toward the evaporator 2.

  Next, in step S <b> 160, it is determined whether the detected value of the evaporator blown air temperature sensor 5 is higher than the detected value of the evaporator blown air temperature sensor 5. When the detected value of the internal temperature sensor 4 is lower than the detected value of the evaporator blown air temperature sensor 5, it is determined as NO, and the blowing of the electric blower 3 is maintained.

  Thereafter, when the detected value of the evaporator blown air temperature sensor 5 becomes higher than the detected value of the evaporator blown air temperature sensor 5, it is determined as YES in step S160 and the electric blower of the electric blower 3 is blown. To stop.

  According to the present embodiment described above, even when the ignition switch IG is turned off and the traveling engine is stopped and the compressor 11 is stopped, the door 7 changes from the open state to the closed state, When the detected value of the temperature sensor 4 is higher than the detected value of the evaporator blown air temperature sensor 5 and the detected value of the evaporator blown air temperature sensor 5 is lower than zero degrees, the blower of the electric blower 3 is started. Accordingly, since the electric blower 3 blows air toward the evaporator 2, cold air is blown from the evaporator 2 due to the heat capacity of the evaporator 2, and the inside of the freezer 1 is cooled by the cold air so that there is no temperature unevenness. As described above, even when the traveling engine is stopped, the air temperature in the freezer can be kept as low as possible.

  4, graphs 1, 2, 3, and 4 are shown in which the vertical axis represents the detection value of the internal temperature sensor 4 and the detection value of the evaporator blown air temperature sensor 5, and the horizontal axis represents time.

  Graph 1 shows the detected value of the internal temperature sensor 4 of the present embodiment, and graph 2 shows the internal temperature sensor when the electric blower 3 is stopped even when the door 7 changes from the open state to the closed state. 4 shows the detection value of the evaporator blown air temperature sensor 5, and graph 4 shows the case where the electric blower 3 is stopped even if the door 7 changes from the open state to the closed state. The detected value of the evaporator blowing air temperature sensor 5 is shown.

  Here, as can be seen from the graphs 1 and 2, in the case of the present embodiment, the temperature sensor inside the chamber is compared with the case where the electric blower 3 is stopped even when the door 7 changes from the open state to the closed state. It can be seen that the detection value of 4 decreases.

  Specifically, in the case of the present embodiment, the temperature in the freezer 1 being stopped (the detected value of the internal temperature sensor 4) is the same as that of the electric blower 3 even if the door 7 changes from the open state to the closed state. Compared to the case of the stop state, the temperature is lowered by 4 ° C. Further, the temperature in the freezer 1 before traveling (when 3 hours have passed since the vehicle stopped) is in a state where the electric blower 3 is stopped even if the door 7 is changed from the open state to the closed state in this embodiment. Compared with the case where it was made, it fell 2.5 degreeC.

  As can be seen from the graphs 3 and 4, in the case of the present embodiment, the evaporator blowout air temperature is lower than when the electric blower 3 is stopped even when the door 7 changes from the open state to the closed state. It can be seen that the detection value of the sensor 5 increases.

(Other embodiments)
In the above-described embodiment, in order to operate the electric blower 3 while the traveling engine is stopped, when the electric blower 3 is operated when the charge amount of the in-vehicle battery B that supplies power to the electric blower 3 is low, the battery is increased. there is a possibility.

  Therefore, the charge amount of the in-vehicle battery B is obtained based on the voltage of the positive terminal of the in-vehicle battery B, and it is determined whether or not the charge amount of the in-vehicle battery B is less than a certain value. And if it determines with the charge amount of the vehicle-mounted battery B being less than a fixed value, ventilation of the electric blower 3 will be stopped.

  In the above-mentioned embodiment, although the example applied to the freezer car provided with one freezer 1 (room) was described, it replaced with this and applied to the multi-room type freezer car provided with the freezer comprised from a plurality of rooms. Also good. Or you may apply the freezing apparatus of the freezing vehicle of this invention to the multi-temperature-type freezing vehicle which can set the temperature of the freezer 1 to the temperature higher than the temperature below zero.

  In the above-mentioned embodiment, although the example using the sensor which detects the air temperature in the freezer 1 was demonstrated as the internal temperature sensor 4, it replaces with this and the internal temperature sensor 4 is a wall surface in the freezer 1 A sensor for detecting the temperature may be used.

  In the above-described embodiment, an example in which the sensor that detects the temperature of the air blown from the evaporator 2 is used as the evaporator blown air temperature sensor 5 has been described. A sensor for detecting the surface temperature of 2 may be used.

It is a figure which shows the whole structure of one Embodiment of the freezing vehicle of this invention. It is a figure which shows the structure of the refrigerating-cycle apparatus applied to the freezing vehicle of FIG. It is a flowchart which shows the control processing of the control apparatus of FIG. It is a graph which shows the detected value of the internal temperature sensor of FIG. 2, and the detected value of an evaporator blowing air temperature sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Freezer, 6 ... Rear side opening part, 7 ... Door, 2 ... Evaporator, 11 ... Compressor,
11a ... electromagnetic clutch, 12 ... condenser, 14 ... liquid receiver, 15 ... expansion valve,
16 ... Gas-liquid separator, R ... Refrigeration cycle device, 17a ... Bypass passage,
17 ... Solenoid valve for defrosting, 10 ... Control device.

Claims (3)

An evaporator that constitutes a refrigeration cycle apparatus together with a compressor driven by an on-vehicle engine, evaporates the refrigerant discharged from the compressor, and cools the air in the freezer;
A blower that is arranged in the freezer and blows air toward the evaporator;
An evaporator temperature sensor for detecting the temperature of the evaporator;
An internal air temperature sensor for detecting an air temperature in the freezer;
A door switch for detecting opening and closing of the freezer door;
Door determination means for determining whether the door of the freezer has changed from an open state to a closed state based on an output signal of the door switch;
Temperature determining means for determining whether or not the detected temperature of the internal air temperature sensor is higher than the detected temperature of the evaporator temperature sensor;
Evaporator temperature determination means for determining whether or not the detected temperature of the evaporator temperature sensor is lower than zero degrees;
When the door determination unit determines that the door of the freezer has changed from an open state to a closed state while the in-vehicle engine is stopped, the detected temperature of the internal air temperature sensor is the detected temperature of the evaporator temperature sensor. If the temperature determination means determines that the detected temperature is lower than zero degree and the evaporator temperature determination means determines that the detected temperature of the evaporator temperature sensor is lower than zero degree, the blow start control for starting the blow of the blower Means,
A refrigeration apparatus for a refrigeration vehicle comprising: When the vehicle engine is stopped, when the temperature determination means determines that the detected temperature of the evaporator temperature sensor is higher than the detected temperature of the internal air temperature sensor, the blow stop control means for stopping the blow of the blower The refrigeration apparatus for a refrigerator car according to claim 1, comprising: The blower includes an electric motor that is powered by an onboard battery and is driven, and an impeller that is driven by the electric motor to generate airflow.
Charge determination means for determining whether or not the charge amount of the in-vehicle battery is less than a certain value,
When the charge determination unit determines that the charge amount of the in-vehicle battery is less than a certain value, the blow stop control unit stops supplying power from the in-vehicle battery to the electric motor and stops blowing air from the blower. The refrigeration apparatus for a refrigerator car according to claim 2.

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