JPH0560428A - Freezing device for transportation - Google Patents

Abstract

PURPOSE:To provide a freezing device for transportation which stops cooling or heating operation while temperature in a freezing chamber is within a range of a given temperature and rotates only a fan for a freezer, and keeps uniformity of temperature in the chamber. CONSTITUTION:A freezing device for transportation is driven by selectively transmitting the powers of an engine 1 and an electric motor 2 to a compressor 3 and controls temperature in a freezer by performing cooling operation and heating operation. A generator 27 driven by the engine 1 is provided. When temperature in a freezer is decreased to a given temperature under cooling operation or temperature in the freezer is increased to a given value under heating operation, the engine 1 is brought into an idling state and cooling operation or heating operation is stopped. A control device 26 to run a fan 13 for feeding air in the freezer to an evaporator 11 with the aid of the generator 27 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus such as a transportation refrigerating unit driven by an engine or a motor.

[0002]

2. Description of the Related Art An example of a conventional refrigeration system is shown in FIG. In FIG. 3, 1 is an engine, 2 is an electric motor driven by a commercial power source or the like, and 3 is a compressor driven by transmission of power of the engine 1 or the electric motor 2. Reference numeral 4 denotes a centrifugal clutch, and when the engine 1 is used, the centrifugal clutch 4 is connected as the rotation speed of the engine 1 increases, so that the compressor 3
Is driven. On the other hand, when the electric motor 2 is used and the compressor 3 is driven, the centrifugal clutch 4 is disengaged so that the power of the electric motor 2 is not transmitted to the engine 1.

A three-way valve 5 is driven by a solenoid 6 to switch between a cooling operation and a heating operation.
Reference numeral 7 is a condenser, and 8 is a fan for blowing outside air to the condenser 7, which is driven by a motor 9. Reference numeral 10 is an expansion valve, 11 is an evaporator disposed in the freezer, 13 is a fan for blowing air inside the refrigerator to the evaporator 11, and is driven by a motor 14. Reference numeral 15 is a thermosensor for detecting the temperature in the freezer, 16 is a control device, 17 is a generator driven by the engine 1 or the electric motor 2, and serves as a driving power source for the motor 9 and the motor 14. A battery 18 is charged by the generator 17.

During the cooling operation, by switching the three-way valve 5, the refrigerant is compressed by the compressor 3, the three-way valve 5, the condenser 7, the expansion valve 10 and the evaporator 11 as shown by the solid arrow.
And then returns to the compressor 3.

On the other hand, during the heating operation, by switching the three-way valve 5, the refrigerant returns to the compressor 3 through the compressor 3, the three-way valve 5 and the evaporator 11 in this order as shown by the dashed arrow.

A signal from the thermo sensor 15 is input to the control device 16, and a command from the control device 16 controls the engine 1, the electric motor 2, the solenoid 6, the motor 9, and the motor 14.

When the load is a cooling load, the heat absorption operation shown by the solid line in FIG. 4 is performed, and when the load is a heating load, the heat radiation operation shown by the broken line in FIG. 4 is performed.

During the endothermic operation, when the internal temperature T reaches point A, that is, the upper limit temperature T1, the engine 1 is started by a command from the control device 16, and the centrifugal clutch 4 is passed through the centrifugal clutch 4 as the engine 1 speed increases. The compressor 3 is driven, the generator 17 is driven, the charging of the battery 18 is started, the motors 9 and 14 are driven, and the refrigeration apparatus starts the cooling operation.

When the temperature T in the refrigerator gradually decreases and reaches the set temperature Ts by the cooling operation of the refrigeration system, that is, at the point B, a command for switching from the cooling operation to the heating operation is output. Then, when the temperature T in the refrigerator rises due to the heating operation of the refrigerating apparatus to reach point C, that is, the upper limit temperature T1, a command to switch from the heating operation to the cooling operation is output. In this way, the in-compartment temperature T is maintained near the set temperature Ts while alternately repeating the cooling operation and the heating operation.

On the other hand, when the load is a heating load, heat radiation operation is performed, and when the internal temperature T reaches the lower limit temperature T2, the heating operation is instructed, and when the set temperature Ts is reached, the heating operation is switched to the cooling operation. Be done. Others are the same as in the endothermic operation.

The above description has been made for the case where the refrigeration system is driven by the engine 1.
The same is true when driven by the electric motor 2.

[0012]

The above-mentioned conventional transportation refrigeration system has the following problems to be solved.

That is, in the above conventional refrigeration apparatus for transportation, the cooling operation and the heating operation are alternately repeated to continuously operate the refrigeration apparatus, and the fan 14 is continuously operated to maintain a uniform temperature distribution in the freezer. However, in addition to the waste of energy caused by the continuous drive of the engine 1 or the motor 2, the switching frequency of the three-way valve 5 is increased and the consumption thereof is accelerated.

In order to solve the above problems, the present invention eliminates the continuous repetition of the cooling operation and the heating operation, stops the compressor while the inside of the freezer is within the required temperature range, and stops the fan 1
It is an object of the present invention to provide a transportation refrigerating device which rotates only 4 pieces.

[0015]

As a means for solving the above problems, the present invention is to provide a transportation refrigerating apparatus described in the following (1) and (2). (1) In the transportation refrigerating apparatus, which is driven by selectively transmitting the power of the engine and the electric motor to the compressor, and controls the temperature in the freezer by performing the cooling operation and the heating operation. When the inside of the freezer falls to a predetermined temperature under the cooling operation and the generator driven by the above, or when the inside of the freezer rises to the predetermined temperature under the heating operation, the engine is idling operated to A transport refrigeration system comprising: a control device for stopping a cooling operation or a heating operation and operating a fan for blowing the air inside the refrigerator to the evaporator by the generator. (2) Cooling operation in a transportation refrigeration system in which the power of an engine and an electric motor is selectively transmitted to a compressor to control the temperature in a freezer by performing a cooling operation and a heating operation. When the inside of the freezer falls to a predetermined temperature under high temperature, or when the inside of the freezer rises to a predetermined temperature under heating operation, the electric motor is stopped to stop the cooling operation or the heating operation, and A transportation refrigerating apparatus comprising a control device for operating a fan for blowing air inside the refrigerator to an evaporator by a power source for driving a motor.

[0016]

Since the present invention is constructed as described above, it has the following actions. (1) In the configuration of (1) above, when the inside of the freezer falls to a predetermined temperature during the cooling operation, or when the inside of the freezer rises to the predetermined temperature during the heating operation, the engine causes the engine to idle. As a result, the cooling operation or the heating operation is stopped, and the fan of the evaporator is continuously operated by the generator driven by this engine, and the air in the freezer is circulated. (2) In the configuration of (2) above, the electric motor is stopped by the control device when the inside of the freezer falls to a predetermined temperature during the cooling operation or when the inside of the freezer rises to the predetermined temperature during the heating operation. By doing so, the cooling operation or the heating operation is stopped, and the fan of the evaporator is continuously operated by the driving power source of the electric motor, and the air in the freezer is circulated.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the inventions of claims 1 and 2 is shown in FIG.
2 will be described. FIG. 1 is a system diagram of a transportation refrigeration system of this embodiment, and FIG. 2 is a switching diagram of the thermostat thereof.

In FIG. 1, the engine 1 has a generator 27.
Are directly connected. The control device 26 has, for example, a thermostat TH1 and a thermostat TH2 built therein, and inputs a signal from the thermosensor 15 to control the engine 1, the solenoid 6, the motor 9, and the motor 14.
As shown in FIG. 2, the thermostat TH1 is turned off when the internal temperature T reaches the set temperature Ts, and is turned on when the internal temperature T reaches the upper limit temperature T1. Further, the thermostat TH2 is turned off when the internal temperature T reaches the set temperature Ts, and is turned on when the internal temperature T reaches the lower limit temperature T2. Other configurations are similar to those of the conventional one shown in FIG.
Corresponding members will be assigned the same reference numerals and explanations thereof will be omitted.

Thus, when the refrigeration system is driven by the engine 1, the compressor 3 is driven by the engine 1.
Also, the generator 27 is driven, and the motor 9 and the motor 14 are driven by the generator 27 to perform the cooling operation or the heating operation.

During the cooling operation, when the internal temperature T decreases and reaches the set temperature Ts, the thermostat T of the controller 26
The engine 1 is idling in response to the operation stop command of H1, the centrifugal clutch 4 is disengaged accordingly, the compressor 3 is stopped, and the refrigeration system stops the cooling operation.
Further, the generator 27 is continuously driven by the power of the engine 1, the motor 14 is driven by the generator 27, and the fan 13 is continuously operated.

After the cooling operation is stopped, the temperature inside the chamber rises due to the intrusion of heat from the outside and the thermostat T
When the temperature reaches the upper limit temperature T1 of H1, the rotation speed of the engine 1 is increased by the operation start command of the thermostat TH1, and thereby the compressor 3 is driven and the cooling operation is restarted.

Thus, the cooling operation is stopped when the inside temperature reaches the set temperature Ts, and during this stop, the air inside the inside is circulated by the fan 13, so that the temperature distribution inside the inside becomes uniform. To be done.

On the other hand, even when the internal temperature T rises to reach the set temperature Ts during the heating operation, the thermostat TH of the controller 26 is also provided, as in the case of the above cooling operation.
When the engine 1 is idling in response to the operation stop command of 2, the centrifugal clutch 4 is disengaged and the compressor 3 is stopped accordingly, the refrigerating apparatus stops heating operation, and the motor 27 is driven by the generator 27. The fan 13 continues to operate.

When the refrigeration system is driven by the electric motor 2, the compressor 3 is driven by the electric motor 2, and a DC power is supplied from a commercial power source (not shown) that drives the electric motor 2 through a transformer and a rectifier. The motor 9 and the motor 14 are driven by the power source to perform the cooling operation or the heating operation.

During the cooling operation, when the internal temperature T decreases and reaches the set temperature Ts, the thermostat T of the control device 26 is set.
The electric motor 2 is stopped by the operation stop command of H2, the compressor 3 is stopped, and the refrigeration apparatus stops the cooling operation. Further, the motor 14 is driven by the power supply for driving the electric motor 2 and the fan 13 continues to operate.

After the cooling operation is stopped, the temperature inside the chamber rises due to the intrusion of heat from the outside or the like, and when the temperature reaches the upper limit temperature T1 of the thermostat TH1 of the control device 26, the operation start command of the thermostat TH1 causes The electric motor 2 is driven, whereby the compressor 3 is driven and the cooling operation is restarted.

Thus, the cooling operation is stopped when the inside temperature reaches the set temperature Ts, and the air inside the inside is circulated by the fan 13 during this stop, so that the temperature distribution inside the inside becomes uniform. To be done.

On the other hand, even when the internal temperature T rises and reaches the set temperature Ts during the heating operation, the electric motor 2 is stopped by the operation stop command of the thermostat TH2 as in the case of the cooling operation. The compressor 3 is stopped, the refrigeration system stops the heating operation, and the motor 14 is driven by the driving power source of the electric motor 2 to continue the operation of the fan 13.

As described above, according to the present embodiment, when the internal cold storage temperature drops to a predetermined temperature during the cooling operation, the control device 26 switches the engine 1 to idling when the engine 1 is driven and the electric motor 2 is driven. In this case, the electric motor 2 is stopped, the compressor 3 is stopped together, and the cooling operation is stopped. On the other hand, the fan 13 is rotated by the current generated by the generator 27 or by the commercial power source to circulate the air in the refrigerator. The internal temperature is kept uniform. Further, when the temperature inside the refrigerator rises to a predetermined temperature during the heating operation, the controller 26 also stops the compressor 3 in each case to stop the heating operation, while the fan 1 is operated.
Since 3 is rotated, the internal temperature is kept uniform.

That is, as in the conventional example, the cooling operation is immediately switched to the heating operation when the inside temperature of the refrigerator is lowered to the predetermined temperature by the cooling operation, and the cooling operation is immediately switched to the cooling operation when the inside temperature is raised to the predetermined temperature by the heating operation. Abandon driving,
While the inside of the refrigerator is in the required temperature range, the compressor 3 is stopped, only the fan 13 rotates, and the temperature of the inside of the refrigerator is kept uniform. Therefore, there is an advantage that the power is remarkably reduced as compared with the conventional example. Further, since the frequency of switching between cooling and heating is reduced, the switching frequency of the three-way valve 5 is correspondingly reduced, which has the advantage of extending its service life.

[0031]

Since the present invention is constructed as described above, it has the following effects. (1) According to the configuration of claim 1, the engine is idling when the inside of the freezer falls to a predetermined temperature during the cooling operation or when the inside of the freezer rises to the predetermined temperature during the heating operation. Since the cooling operation or the heating operation is stopped by this, the fuel consumption can be reduced, and the frequency of the switching operation of the three-way valve is reduced, so that its durability is improved.

Further, during the suspension of the cooling operation or the heating operation, the fan of the evaporator is continuously operated by the generator driven by the engine, so that the temperature in the freezer can be maintained in a uniform state. (2) According to the configuration of claim 2, when the inside of the freezer falls to a predetermined temperature during the cooling operation, or when the inside of the freezer rises to the predetermined temperature during the heating operation, the electric motor is stopped and the cooling is performed. Since the operation or the heating operation is stopped, the power consumption can be reduced, and the frequency of the switching operation of the three-way valve is reduced, so that the durability thereof is improved.

Further, while the cooling operation or the heating operation is stopped, the fan of the evaporator is continuously operated by the power source for driving the electric motor, so that the temperature in the freezer can be maintained in a uniform state.

[Brief description of drawings]

FIG. 1 is a system diagram of a refrigerating apparatus according to an embodiment of the present invention,

FIG. 2 is a switching diagram of the thermostat of the above embodiment,

FIG. 3 is a system diagram showing a conventional refrigeration system,

FIG. 4 is an operation switching diagram of a conventional refrigeration system.

[Explanation of symbols]

 1 Engine 2 Electric Motor 3 Compressor 11 Evaporator 13 Fan 26 Control Device 27 Generator

Claims (2)

[Claims] 1. A transport refrigerating apparatus which is driven by selectively transmitting power of an engine and an electric motor to a compressor, and controls a temperature in a freezer by performing a cooling operation and a heating operation, A generator driven by the engine, and when the inside of the freezer is lowered to a predetermined temperature under the cooling operation, or when the inside of the freezer is raised to a predetermined temperature under the heating operation, the engine is idling operated. And a cooling device for stopping the cooling operation or the heating operation and operating a fan for blowing the air inside the refrigerator to the evaporator by the generator. 2. A transportation refrigerating apparatus, which is driven by selectively transmitting power of an engine and an electric motor to a compressor, and controls a temperature in a freezer by performing a cooling operation and a heating operation, When the inside of the freezer falls to a predetermined temperature under cooling operation, or when the inside of the freezer rises to a predetermined temperature under heating operation, the electric motor is stopped to stop the cooling operation or heating operation, A transportation refrigeration apparatus comprising a control device for operating a fan for blowing air in the refrigerator to an evaporator by a power source for driving the electric motor.