JP2013002803A - Refrigerating device for trailer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance energy saving in a refrigerating device for a trailer by changing rotation speed of a motor of a compressor to follow the variation of a cooling load in a container without using an inverter.SOLUTION: The refrigerating device (10) for the trailer includes a throttle adjusting mechanism (6) for adjusting rotation speed of the compressor motor (7) by varying rotation speed of an engine (2) for power generation to change the frequency and voltage of AC power, and a control controller (40) for adjusting a cooling capacity in the container (51) by controlling the throttle adjusting mechanism (6) based on the cooling load in the container (51).

Description

    The present invention relates to a trailer refrigeration apparatus, and more particularly to an energy saving technique for a trailer refrigeration apparatus.

    Conventionally, a trailer refrigeration apparatus that cools a refrigerated container for transporting frozen food or the like on land is known. Such a trailer refrigeration apparatus includes a refrigerant circuit that performs a refrigeration cycle, for example, as disclosed in Patent Document 1, and cools the inside of a container with an evaporator connected to the refrigerant circuit. The compressor connected to the refrigerant circuit incorporates an electric motor for driving the compressor, and the electric motor is driven by electric power generated by a generator provided in the trailer refrigeration apparatus.

    By the way, when the electric motor of the compressor is a constant speed motor, the refrigeration capacity of the trailer refrigeration system does not change because the compressor operating capacity is constant. Does not increase or decrease following. For this reason, the start and stop of a constant speed motor increases, and the energy-saving property of the refrigeration apparatus for trailers falls.

    Thus, it is conceivable to provide an inverter between the generator and the electric motor. With this inverter, the frequency and voltage of the AC power supplied from the generator to the electric motor can be changed, and the rotational speed of the electric motor can be freely changed within a predetermined range in accordance with the fluctuation of the cooling load. It becomes possible. As a result, the operating capacity of the compressor can be varied, and the refrigeration capacity of the trailer refrigeration apparatus can be increased or decreased following changes in the cooling load in the container, thereby improving the energy saving performance of the trailer refrigeration apparatus. .

European Patent Application No. 1046543

    However, the rated current amount of the compressor in the trailer refrigeration system is larger than that of, for example, a compressor for a general-purpose air conditioner. When the inverter is mounted on the trailer refrigeration system, the inverter must have a large capacity. I must. In this case, if a large-capacity inverter is to be mounted on the trailer refrigeration apparatus, there is a problem that the weight of the trailer refrigeration apparatus increases by the amount of the inverter. Also, the manufacturing cost of the trailer refrigeration system increases by the amount of the inverter.

    The present invention has been made in view of such a point, and the object thereof is to change the rotation speed of the motor of the compressor so as to follow the fluctuation of the cooling load in the container without using an inverter, and for a trailer. The purpose is to improve energy saving in the refrigeration system.

    The first invention is electrically connected directly to a compression mechanism (37) connected to a refrigerant circuit (30) that cools the inside of the container (51) and an AC motor (7) that rotationally drives the compression mechanism (37). The generator (3) and the generator (3) mechanically connected to the generator (3) to generate AC power input from the generator (3) to the AC motor (7) Rotation of the AC motor (7) by changing the frequency and voltage of the AC power by changing the rotational speed of the power generation engine (2) and the power generation engine (2) The number of rotations adjusting mechanism (6) for adjusting the number and the number of rotations adjusting mechanism (6) are controlled based on the cooling load in the container (51) to adjust the cooling capacity in the container (51). And a control unit (40).

    In the first invention, unlike the prior art, the generator (3) and the AC motor (7) are electrically connected directly without using an inverter. As described above, when an inverter is used, the frequency and voltage of AC power supplied from the generator (3) to the AC motor (7) are adjusted by the inverter, so that the AC motor (7) The rotation speed was changed. In the case of the first invention, the frequency of the AC power generated in the generator (3) is changed by changing the rotation speed of the generator engine (2) and changing the rotation speed of the generator (3). The voltage is adjusted to change the rotational speed of the AC motor (7).

    Thus, the rotational speed of the AC motor (7) can be changed without using an inverter, and by changing the operating capacity of the compression mechanism (37) along with the change in the rotational speed, The cooling capacity of the trailer refrigeration system (10) is adjusted.

      The second invention is the air fan (36, 35) for sending air to the air-cooled heat exchanger (32, 34) of the refrigerant circuit (30) in the first invention, and the generator (3) Are connected in parallel with the AC motor (7) to rotate the air fan (36, 35), the motor (12, 13), the generator (3), and the fan motor (12, 13), the frequency and voltage of the AC power from the generator (3) to the fan motor (12, 13) is changed to a desired value from the value changed by the rotation speed adjustment mechanism (6). It is characterized by having a power conversion circuit (4, 5) for converting to a value.

    In the second invention, an AC motor (7) and a fan motor (12, 13) are connected in parallel to the generator (3). As described above, the frequency and voltage of the AC power generated in the generator (3) are adjusted according to the cooling load of the container (51) so that the rotational speed of the AC motor (7) is optimized. . For this reason, when the AC power adjusted in this way is input to the fan motor (12, 13), the fan motor (12, 13) is synchronized with the AC motor (7), and the fan motor (12 , 13) may interfere with operation control.

    Therefore, a power conversion circuit (4,5) is electrically connected between the generator (3) and the fan motor (12,13), and the fan motor is connected to the power conversion circuit (4,5). Adjust the frequency and voltage of AC power suitable for the control of (12, 13).

    According to a third aspect of the present invention, in the first or second aspect, the rotation speed adjustment mechanism (6) is configured so that the cooling load is the maximum cooling load determined for the container (51). The engine (2) is set so that the number of revolutions is the maximum number of revolutions.

    In the third aspect of the invention, the power generation engine (2) can be driven at a higher rotational speed (maximum rotational speed) than the rated rotational speed by the rotational speed adjusting mechanism (6). Then, the maximum number of revolutions of the power generation engine (2) can be set so as to correspond to the maximum cooling load of the container (51).

    According to a fourth invention, in any one of the first to third inventions, by returning a part of the refrigerant sucked into the compression mechanism (37) to the suction side of the compression mechanism (37), A discharge amount adjusting mechanism (38) for adjusting a discharge amount of the refrigerant discharged from the mechanism (37), and the control unit (40) is configured to adjust the rotation speed adjustment mechanism based on a cooling load in the container (51). The discharge capacity adjusting mechanism (38) is controlled together with (6) to adjust the cooling capacity in the container (51).

    In the fourth invention, not only the rotation speed of the power generation engine (2) is adjusted by the rotation speed adjustment mechanism (6) but also the refrigerant return amount is adjusted by the discharge amount adjustment mechanism (38). 37) Adjust the operating capacity. Here, since the discharge amount adjustment mechanism (38) can directly change the refrigerant flowing through the refrigerant circuit (30), the operation capacity can be adjusted more finely than the rotation speed adjustment mechanism (6). It becomes. From this, the rough adjustment of the operating capacity of the compression mechanism (37) is performed by the rotation speed adjustment mechanism (6), and then the fine adjustment is performed by the discharge amount adjustment mechanism (38). The cooling capacity of the trailer refrigeration system (10) can be adjusted.

    A fifth invention is characterized in that, in any one of the first to fourth inventions, the generator (3) is an asynchronous generator (3).

    In the fifth invention, the trailer refrigeration apparatus (10) includes an asynchronous generator (3). Here, the synchronous generator with higher power generation efficiency than the asynchronous generator (3) is generally not used because the waveform related to the AC power generated by the synchronous generator is asynchronous. It is because it is easy to be confused compared with the thing. Normally, when a synchronous generator is used, the waveform is adjusted by an inverter / converter. In the present invention, the AC motor (7) and the generator (3) are electrically connected directly, and the inverter / converter Is not connected. For this reason, an asynchronous type generator is used as the generator for the trailer refrigeration system.

    According to the present invention, the frequency and voltage of AC power supplied to the AC motor (7) are adjusted by changing the rotational speed of the power generation engine (2) without using an inverter, and the AC motor (7) The rotation speed can be changed. Accordingly, the cooling capacity of the trailer refrigeration apparatus (10) can be adjusted by changing the operating capacity of the compression mechanism (37) according to the cooling load of the container (51), and the trailer refrigeration apparatus ( 10) Energy saving can be improved. Further, the trailer refrigeration apparatus (10) can be reduced in weight by not using the inverter. Moreover, the manufacturing cost of the trailer refrigeration apparatus (10) is reduced by the amount not using the inverter.

    According to the second aspect of the present invention, even when the AC motor (7) and the fan motor (12, 13) are connected in parallel to the generator (3), the fan motor (12, 13) side is provided. By adjusting the frequency and voltage of AC power supplied from the generator (3) to the fan motor (12, 13) with the provided power conversion circuit (4, 5), the fan motor (12, 13) It can be driven stably.

    Further, according to the third aspect, the power generation engine (2) can be driven at a rotational speed (maximum rotational speed) larger than the rated rotational speed by the rotational speed adjustment mechanism (6).

    Here, in the case of the power generation engine (2) that does not use the rotational speed adjustment mechanism (6), the power generation engine (2) can be driven only at the rated rotational speed. For this reason, it is common to select the power generation engine (2) so as to be able to cope with the maximum cooling load of the container (51) at this rated rotational speed. However, according to the third aspect of the invention, the rotational speed adjustment mechanism (6) can increase the rotational speed of the power generation engine (2), so that the power generation engine (2) can be made smaller and lighter accordingly. Can be

    According to the fourth aspect of the invention, when adjusting the operating capacity in the compression mechanism (37), rough adjustment is performed by the rotation speed adjustment mechanism (6), and the fine adjustment thereafter is performed by adjusting the discharge amount. This can be done with the mechanism (38). Thereby, according to the fluctuation | variation of the cooling load in a container (51), the cooling capacity of the said trailer refrigeration apparatus (10) can be tracked accurately.

    Further, according to the fifth aspect of the invention, an asynchronous type generator is used as the generator of the trailer refrigerating apparatus (10). Thereby, the disturbance of the waveform of the alternating current power generated from this generator becomes smaller than that of the synchronous type, and the rotation control of the alternating current motor (7) can be performed satisfactorily.

FIG. 1 is a side view of a refrigeration vehicle provided with a refrigeration apparatus according to an embodiment. FIG. 2 is a piping system diagram showing a refrigerant circuit of the refrigeration apparatus. FIG. 3 is a schematic system diagram illustrating a power supply unit and a controller according to the embodiment.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

    The trailer refrigeration apparatus (10) of the present embodiment (hereinafter simply referred to as the refrigeration apparatus (10)) is a large refrigeration vehicle (50) that transports frozen food, fresh food, etc., as shown in FIG. Used. In this refrigeration vehicle (50), a driving vehicle (52) provided with a cab and a traveling engine and a carrier vehicle (53) loaded with a container (51) are detachably connected. A freezer compartment is formed inside the container (51). And the freezing apparatus (10) of this embodiment is attached to the outer surface of a container (51), and is for cooling the inside of a freezer. The refrigeration apparatus (10) includes a refrigerant circuit (30), a power supply unit (1), and a controller (control unit) (40).

<Refrigerant circuit>
As shown in FIG. 2, the refrigerant circuit (30) performs a refrigeration cycle in which a compressor (31), a condenser (32), an electronic expansion valve (33), and an evaporator (34) are sequentially connected by piping. It is configured as follows.

    The compressor (31) has a substantially cylindrical casing closed at both ends. And in this casing, the compression mechanism (37) and the compressor motor (alternating current motor) (7) mutually connected with the drive shaft are accommodated. The compression mechanism (37) is driven by the compressor motor (7) and sucks the low-pressure gas refrigerant evaporated by the evaporator (34), and then compresses the low-pressure gas refrigerant to a predetermined pressure to compress the high-pressure gas refrigerant. A high-pressure gas refrigerant is discharged toward the condenser (32).

    The compressor (31) is provided with an unload mechanism (discharge amount adjusting mechanism) (38). A part of the refrigerant sucked into the compression mechanism (37) by the unload mechanism (38) can be returned to the suction side of the compression mechanism (37), and the return amount of the refrigerant is changed within a predetermined range. Thereby, the discharge amount in the high-pressure gas refrigerant from the compression mechanism (37) is adjusted. When the return amount of the refrigerant is increased, the discharge amount of the high-pressure gas refrigerant is decreased. Conversely, when the return amount of the refrigerant is decreased, the discharge amount of the high-pressure gas refrigerant is increased.

    The compressor motor (7) is an AC motor. By changing the frequency and voltage of AC power input to the AC motor, the rotational speed of the AC motor can be changed.

    Both the condenser (32) and the evaporator (34) are cross fin type fin-and-tube heat exchangers. The condenser (32) is disposed outside the freezer compartment in the container (51). The condenser (32) exchanges heat between the outside air taken in by the outside fan (36) in the vicinity of the condenser (32) and the high-pressure gas refrigerant in the refrigerant circuit (30). . The external fan (36) is provided with a fan motor (12) for rotating a propeller fan (39) provided on the external fan (36).

    The condenser-side fan motor (12) is an AC motor. By changing the frequency and voltage of AC power input to the AC motor, the rotational speed of the AC motor can be changed.

    On the other hand, the evaporator (34) is disposed inside the freezer compartment in the container (51). Heat is exchanged between the internal air taken in by the internal fan (35) in the vicinity of the evaporator (34) and the low-pressure refrigerant of the refrigerant circuit (30). The external fan (36) is provided with a fan motor (13) for rotating a propeller fan (45) provided in the external fan (36).

    The evaporator side fan motor (13) is an AC motor. By changing the frequency and voltage of AC power input to the AC motor, the rotational speed of the AC motor can be changed.

    Then, by the heat exchange in the evaporator (34), the low-pressure refrigerant absorbs the heat of the internal air and evaporates, and the internal air takes heat from the low-pressure refrigerant and is cooled. Thus, the inside of the container (51) is cooled by cooling the internal air.

<Power supply section>
The power supply unit (1) includes a generator engine (2), a generator (3), a converter (5), and an inverter (4). The compressor motor (7) and the fan motor (12, 13) described above. ) To supply AC power.

    The power generation engine (2) is dedicated to the refrigeration system provided separately from the traveling engine of the driving vehicle (52). The power generation engine (2) is provided with a throttle adjustment mechanism (rotational speed adjustment mechanism) (6). The throttle adjustment mechanism (6) adjusts the fuel supply amount, and the operating rotational speed of the power generation engine (2) can be changed within a predetermined range. In the present embodiment, the operating rotational speed of the power generation engine (2) can be changed between 1000 rpm and 3000 rpm.

    The generator (3) is mechanically directly connected to the power generation engine (2) via a joint, for example. The power of the power generation engine (2) drives the generator (3) to generate AC power. The frequency and voltage of the AC power can be adjusted by the rotational speed of the generator (3), that is, the rotational speed of the generator engine (2) directly connected to the generator (3).

    Also, as shown in FIG. 3, a compressor motor (7) and fan motors (12, 13) are electrically connected in parallel to the generator (3). Here, the generator (3) and the compressor motor (7) are directly connected, and a converter (4,5) as a power conversion circuit (4,5) is connected between the generator (3) and the fan motor (12,13). 5) and the inverter (4) are connected.

    The converter (5) converts AC power supplied from the generator (3) to the fan motor (12, 13) side into DC power. The inverter (4) converts the DC power converted by the converter (5) into AC power.

    The generator (3) is an asynchronous type. Here, the synchronous generator with higher power generation efficiency than the asynchronous generator (3) is generally not used because the waveform related to the AC power generated by the synchronous generator (3) is This is because it is more confusing than the asynchronous type. Normally, when a synchronous generator is used, an inverter / converter is used to reduce the above-mentioned waveform disturbance. In this embodiment, the AC motor (7) and the generator (3) are electrically connected. Directly connected, no inverter / converter is connected between AC motor (7) and generator (3). For this reason, an asynchronous type generator is used as the generator (3) for the refrigeration system.

    The inverter (4) converts the DC power converted by the converter (5) into AC power. In this conversion, the frequency and voltage of the AC power are adjusted to desired values, that is, optimum values for efficiently cooling the container (51). The adjusted AC power is input to each fan motor (12, 13).

<Control controller>
The controller (40) optimally controls the refrigeration capacity of the refrigeration apparatus based on the cooling load in the container (51), and includes a cooling load detector (41), a cooling capacity controller (42), And a fan control unit (43).

    The cooling load detector (41) detects a cooling load in the container (51), and is connected to a temperature sensor (44) that detects the temperature in the container (51). The cooling load detector (41) calculates a cooling load value based on the detected value of the temperature sensor (44).

    The cooling capacity control unit (42) adjusts the cooling capacity of the refrigeration apparatus (10) by increasing or decreasing the refrigerant discharge amount of the compression mechanism (37). In this cooling capacity control unit (42), in order to increase or decrease the refrigerant discharge amount of the compression mechanism (37), the throttle adjustment mechanism (6) of the power generation engine (2), the unload mechanism (38) of the compressor, To control. Specifically, the rotation speed of the compressor motor (7) is adjusted without using the inverter (4) by the control of the throttle adjustment mechanism (6), and the control of the unload mechanism (38) The return amount of the refrigerant related to the compression mechanism (37) is adjusted.

    In the case of the throttle adjustment mechanism (6), the compressor as in the inverter (4) is used to adjust the rotational speed of the compressor motor (7) by changing the amount of fuel supplied to the power generation engine (2). Compared to the case where the frequency and voltage of the AC power input to the motor (7) are directly changed, it is difficult to finely adjust the rotational speed of the compressor motor (7). For this reason, in the cooling capacity control section (42), a rough adjustment of the rotation speed of the compressor motor (7) is performed by the throttle adjustment mechanism (6), and the refrigerant discharge amount of the compression mechanism (37) is finely adjusted. Is configured to be performed by the unload mechanism (38).

    The fan control unit (43) controls the converter (5) and the inverter (4) so that the frequency and voltage of AC power input to each fan motor (12, 13) ) To adjust to a desired value suitable for the operation state. As described above, the compressor motor (7) and the fan motor (12, 13) are connected in parallel to the generator (3), and the frequency and voltage of the AC power generated by the generator (3) are as follows. Changes according to the cooling load of the container (51).

    Therefore, when AC power having the same frequency and voltage is input to both the compressor motor (7) and the fan motor (12, 13), the compressor motor (7) and the fan motor (12, 13) Since it operates synchronously, it interferes with the operation control of the fan motors (12, 13).

    In the fan controller (43), from the generator (3) to the fan motor (12, 13) so that the fan motor (12, 13) does not operate in synchronization with the compressor motor (7). Only the frequency and voltage of the supplied AC power are adjusted to a desired value. As a result, the frequency and voltage of the AC power supplied to the fan motor (12, 13) can be made different from the frequency and voltage of the AC power supplied to the compressor motor (7). 12,13) Operation control is not hindered.

-Driving action-
Next, the operation of the refrigeration apparatus (10) of this embodiment will be described.

    First, the generator engine (2) is started and the generator (3) is rotated according to the operation command of the controller (40). As a result, AC power is generated in the generator (3), and the generated AC power is supplied to the compressor motor (7) and the fan motors (12, 13), so that the compressor motor (7 ) And each fan motor (12, 13) is driven.

    By driving the compressor motor (7), the compression mechanism (37) of the compressor (31) is driven, and the refrigerant circulates in the refrigerant circuit (30). The fan motors (12, 13) are driven to drive the internal fan (35) and the external fan (36), and the evaporator (34) of the refrigerant circuit (30) is driven from the internal fan (35). ) To the condenser (32) of the refrigerant circuit (30) from the outside fan (36).

    By the heat exchange in the evaporator (34), the low-pressure refrigerant in the evaporator (34) absorbs the heat of the internal air and evaporates, and the internal air is cooled by taking heat from the low-pressure refrigerant. The Thus, the inside of the container (51) is cooled by cooling the internal air.

    Next, operation control of the controller (40) when the cooling load in the container (51) fluctuates will be described.

    In the controller (40), the cooling load value in the container (51) is calculated by the cooling load detector (41). The cooling load value is input to the cooling capacity control unit (42).

    When the cooling capacity control unit (42) determines that the cooling load value in the container (51) has increased, the cooling capacity value of the refrigeration apparatus (10) follows the same value as the cooling load value. Therefore, the throttle adjustment mechanism (6) is commanded to increase the amount of fuel supplied to the power generation engine (2). Then, with the increase in the engine speed in the power generation engine (2), the speed of the generator (3) also increases. As a result, the frequency and voltage of the AC power generated by the generator (3) increase, and the rotational speed of the compressor motor (7) increases.

    As the rotational speed of the compressor motor (7) increases, the operating capacity of the compression mechanism (37) increases, and the amount of refrigerant discharged from the compression mechanism (37) increases, and the refrigerant circuit (30) The circulation amount of the circulating refrigerant increases. Thereby, the cooling capacity value of the refrigeration apparatus (10) and the cooling load value are balanced.

    On the other hand, when the cooling capacity control unit (42) determines that the cooling load value in the container (51) has become small, it instructs the throttle adjustment mechanism (6) to supply fuel to the power generation engine (2). Reduce the amount. Then, with the decrease in the engine speed in the power generation engine (2), the speed of the generator (3) also decreases. Thereby, the frequency and voltage of the alternating current power which generate | occur | produces with the said generator (3) become small, and the rotation speed of the said compressor motor (7) falls.

    By reducing the rotational speed of the compressor motor (7), the operating capacity of the compression mechanism (37) is reduced and the amount of refrigerant discharged from the compression mechanism (37) is reduced. The circulation amount of the circulating refrigerant decreases. Thereby, the cooling capacity value of the refrigeration apparatus (10) and the cooling load value are balanced.

    Here, in the cooling capacity control unit (42), for example, when the cooling capacity value of the refrigeration apparatus (10) hunts with respect to the cooling load value, the unload mechanism (38) is commanded to The refrigerant return amount related to the compression mechanism (37) is adjusted. Thereby, the amount of the refrigerant discharged from the compression mechanism (37) can be finely adjusted. By this fine adjustment, the cooling capacity value of the refrigeration apparatus (10) and the cooling load value can be accurately balanced.

-Effect of the embodiment-
According to the present embodiment, the frequency and voltage of the AC power supplied to the compressor motor (7) are adjusted by changing the rotational speed of the power generation engine (2) without using an inverter, The number of rotations of the compressor motor (7) can be changed. Thereby, the operating capacity of the compression mechanism (37) can be changed in accordance with the cooling load of the container (51), and the cooling capacity of the container refrigeration equipment can be adjusted. Energy saving can be improved. Further, the trailer refrigeration apparatus (10) can be reduced in weight by not using the inverter. Moreover, the manufacturing cost of the trailer refrigeration apparatus (10) is reduced by the amount not using the inverter.

    Further, according to the present embodiment, even when the compressor motor (7) and the fan motor (12, 13) are connected in parallel to the generator (3), it is provided on the fan motor (12, 13) side. By adjusting the frequency and voltage of the AC power supplied from the generator (3) to the fan motor (12, 13) by the converter (5) and inverter (4), the fan motor (12, 13) It can be driven stably.

    Further, according to this embodiment, the throttle adjusting mechanism (6) can drive the power generation engine (2) at a rotational speed (maximum rotational speed) larger than the rated rotational speed. The power generation engine (2) can be reduced in size and weight as much as the rotation speed of 2) can be increased.

    Here, in the case of the power generation engine (2) that does not use the throttle adjustment mechanism (6), the power generation engine (2) can be driven only at the rated speed. For this reason, it is common to select the power generation engine (2) so as to be able to cope with the maximum cooling load of the container (51) at this rated rotational speed. However, according to the present embodiment, the rotational speed of the power generation engine (2) can be increased by the throttle adjustment mechanism (6), and accordingly, the power generation engine (2) is reduced in size and weight. be able to.

    Further, according to the present embodiment, when adjusting the operating capacity in the compression mechanism (37), rough adjustment is performed by the throttle adjustment mechanism (6), and the fine adjustment thereafter is performed by the unload mechanism (38). Can be done. Thereby, according to the fluctuation | variation of the cooling load in a container (51), the cooling capacity of the said trailer refrigeration apparatus (10) can be tracked accurately.

    Further, according to the present embodiment, an asynchronous type generator is used for the trailer refrigeration apparatus (10). Thereby, the disturbance of the waveform of the alternating current power generated from this generator becomes smaller than that of the synchronous type, and the rotation control of the compressor motor (7) can be performed satisfactorily.

    As described above, the present invention relates to a trailer refrigeration apparatus, and is particularly useful for an energy saving technique of a trailer refrigeration apparatus.

1 Power supply unit
2 Power generation engine
3 Generator
4 Inverter
5 Converter
6 Throttle adjustment mechanism (rotational speed adjustment mechanism)
7 Compressor motor (AC motor)
10 Trailer refrigeration equipment
30 Refrigerant circuit
38 Unload mechanism (Discharge rate adjustment mechanism)
40 Control controller (control unit)
41 Cooling load detector
42 Cooling capacity controller
43 Fan controller
50 Refrigerator
51 containers

Claims (5)

A compression mechanism (37) connected to a refrigerant circuit (30) for cooling the inside of the container (51);
A generator (3) electrically connected directly to an AC motor (7) that rotationally drives the compression mechanism (37);
For power generation that is mechanically connected to the generator (3) and rotationally drives the generator (3) to generate AC power input from the generator (3) to the AC motor (7) Engine (2),
A rotation speed adjustment mechanism (6) for adjusting the rotation speed of the AC motor (7) by changing the rotation speed of the power generation engine (2) and changing the frequency and voltage of the AC power;
A control unit (40) for controlling the rotation speed adjustment mechanism (6) based on a cooling load in the container (51) to adjust the cooling capacity in the container (51);
A trailer refrigeration apparatus comprising: In claim 1,
An air fan (36, 35) for sending air to the air-cooled heat exchanger (32, 34) of the refrigerant circuit (30);
A fan motor (12,13) connected in parallel to the generator (3) together with the AC motor (7) and rotationally driving the air fan (36,35);
Connected between the generator (3) and the fan motor (12, 13), the frequency and voltage of AC power from the generator (3) to the fan motor (12, 13) are set to the number of revolutions. A power conversion circuit (4, 5) for converting the value changed by the adjustment mechanism (6) to a desired value;
A trailer refrigeration apparatus comprising: In claim 1 or 2,
The rotation speed adjustment mechanism (6) is configured so that the rotation speed of the power generation engine (2) becomes a maximum rotation speed when the cooling load is a maximum cooling load determined for the container (51). A trailer refrigeration apparatus characterized by being set. In any one of Claims 1-3,
A discharge amount adjusting mechanism that adjusts the discharge amount of the refrigerant discharged from the compression mechanism (37) by returning a part of the refrigerant sucked into the compression mechanism (37) to the suction side of the compression mechanism (37). (38)
The control unit (40) controls the discharge amount adjusting mechanism (38) together with the rotation speed adjusting mechanism (6) based on the cooling load in the container (51), thereby cooling the container (51). The trailer refrigeration apparatus characterized by adjusting the temperature. In any one of Claims 1-4,
The trailer refrigeration apparatus, wherein the generator (3) is an asynchronous generator (3).

Images