KR20200083878A - Cooling system of electric drive type for refrigerator vehicle - Google Patents

Abstract

The present invention relates to an electrically driven cooling system for a refrigerator truck. According to the present invention, the electrically driven cooling system for a refrigerator truck comprises: a power supply device; a battery; an electrically driven compressor; a condenser; a liquid receiver; an expander; an evaporator; a defrosting device; a liquid separator; a temperature sensor; and a control part for controlling the power supply device according to an electric signal output from the temperature sensor. According to the present invention, fuel consumption can be reduced.

Description

Cooling system of electric drive type for refrigerator vehicle}

The present invention relates to an electric-driven cooling system of a refrigeration truck, and more specifically, to allow electricity generated during engine operation in a refrigeration truck to accumulate in a battery, and then to drive a compressor with electric energy applied from the battery, or The electric energy generated from the generator-integrated auxiliary engine can be directly supplied with electric energy or external power, so that the compressor can be driven, causing load fluctuations during engine operation, frequent opening/closing of the storage tank, or even when the engine of the refrigerator truck stops. (積載庫) By keeping the internal temperature within a certain range at all times, to prevent corruption of transport cargo and to maintain freshness, and to increase the efficiency of energy utilization to reduce fuel costs while reducing fossil fuels. It relates to an electric-driven cooling system of a refrigeration truck to reduce the amount of fine dust and CO ₂ emissions.

In general, a refrigerated truck is a kind of special vehicle that cools the inside of a storage box by using a cooling system to prevent corruption of cargo contained in the storage box and maintain freshness.

The cooling system of such a refrigeration truck can be roughly divided into an engine-driven cooling system and an axial-cooled cooling system. In the engine-driven cooling system, a generator of a refrigeration truck converts the rotational power of the engine into electrical energy and receives the electrical energy. When the refrigerant is compressed to high temperature and high pressure and supplied to the condenser, the condenser cools and liquefies the compressed refrigerant, and the liquefied refrigerant passes through the expander and is maintained at a low pressure that is easy to vaporize, and the refrigerant maintained at a low pressure is used as an evaporator. It is supplied to absorb heat from the surrounding area while evaporating by the evaporator so that heat exchange that generates cold air is achieved.

The engine-driven cooling system can be divided into a main type and a server type again. In the main-type engine-driven cooling system, a fuel-supplied engine is connected to a generator and a belt, and the generator is mechanical energy due to engine rotational force. To convert it into electrical energy and supply it to the cooling system using electric wiring to drive the compressor, condenser and evaporator of the cooling system.

However, in general, as the rotational speed of the rotor increases, the output voltage also increases. Therefore, the refrigeration truck using the main type engine-driven cooling system as described above is a generator according to the operating state of the engine (change in engine rpm). Since the output voltage is irregular, the compressor operates unstable, and when the engine is stopped, the generator is also stopped, so the operation of the cooling system is also impossible.

Therefore, there is a problem in that the quality of the transport cargo is deteriorated because the inside of the loading dock of the refrigeration truck cannot be maintained at a low temperature.

On the other hand, the server-type engine-driven cooling system is installed in communication with the inner surface of the upper and upper surfaces of the loading bar, and an external power supply, generator, compressor, and condenser on the upper and upper side of the loading box. Is installed, it is configured to be installed in the evaporator on the front upper back surface of the storage.

Accordingly, the external power supply operates separately from the engine of the vehicle, and the generator generates electrical energy by driving the external power supply, and the compressor, condenser, and evaporator are driven using the electrical energy.

This server-type engine-driven cooling system has the advantage of being able to drive the cooling system using an external power supply even when the engine of the vehicle is stopped, but the construction cost of the cooling system is required because a separate external power supply must be provided. This has the disadvantage of increasing.

On the other hand, the axial cooling system is equipped with an axial cooling system in which a suitable phase change material (PCM) is sealed in a cold storage plate or a specific type of container to maintain the temperature in the storage area, accumulating cold air by night electricity and separately during the daytime. It is a method to maintain the internal temperature of the storage box at a low temperature without a power source.

Such an axial cooling system does not consume fuel and does not use refrigerant compared to an engine-driven cooling system, so it is environmentally friendly, has no operational noise, and has a low probability of failure.

However, the cooling time of the cooling plate is long, there is a problem that the cooling function is lost when all the cold air stored in the cooling plate is consumed, and the load burden due to the weight of the cooling plate itself is large compared to the engine-driven cooling system.

As a supplement to the above-mentioned disadvantages of the engine-driven cooling system, Korean Patent Registration No. 10-0629106 (name: automatic engine starting system of a temperature controller for a refrigerated vehicle, hereinafter referred to as'prior technology') has been proposed. .

The prior art, as shown in Figure 1,'in the automatic engine starting system of the temperature controller for a frozen vehicle, a mode setting unit for selecting a temperature setting and an automatic / manual mode in the freezing tower; A temperature sensor attached to the freezing tower to detect the temperature in the freezing tower as an electrical signal in real time when selecting an automatic mode in the mode setting unit; A temperature signal conversion unit that automatically generates an on/off signal to the temperature controller when the output signal from the temperature sensor is an operation/stop condition of the refrigerator; A power and temperature display unit for turning on/off the power lamp and temperature display lamp of the temperature controller when the on/off signal is generated by the temperature signal conversion unit; A control unit sequentially receiving the output signal of the temperature signal conversion unit and generating driving/blocking signals for driving the engine starting motor and the refrigerator; And an engine start motor relay drive unit and a freezer relay drive unit that respectively drive the engine start motor drive relay and the refrigerator drive relay by receiving the drive/block signals from the control unit. By attaching a temperature sensor to the refrigerated vehicle, it is possible to automatically control the engine start of the vehicle and the operation of the refrigerator according to the temperature in the freezer even when the driver is absent.

However, the prior art has a serious problem of causing environmental pollution due to emission of exhaust gas as well as economically disadvantageous as fuel consumption is increased because the engine idling rate is considerably high.

1. Republic of Korea Registered Patent Publication No. 10-0629106, "Automatic engine starting system of temperature controller for frozen vehicles".

The present invention is to solve such a conventional problem, the purpose of which is to drive the compressor with electric energy applied from the battery after the electricity generated when the engine is driven in the refrigeration truck is stored in the battery (蓄電) or integrated generator It is to provide an electric-driven cooling system of a new refrigeration truck that is capable of driving a compressor by directly receiving electric energy or external power generated from an auxiliary engine.

Another object of the present invention is that the temperature inside the storage tank (탑) of the freezing truck is always within a certain range even when load fluctuation (engine rpm change) occurs when the engine is driven, or when the engine is stopped or opened or closed frequently. It is to provide an electric-driven cooling system of a new refrigeration truck that can be maintained.

Another object of the present invention is to prevent the corruption of transport cargo and maintain freshness by keeping the temperature inside the loading tank of the freezing truck always within a certain range even when the engine of the freezing truck is stopped. It is to provide an electric-driven cooling system for new refrigeration trucks that can reduce fuel costs by increasing efficiency while reducing fine dust and CO ₂ emissions through reduction of fossil fuels.

In order to achieve the above object, the present invention includes a power supply device comprising an engine and a generator integrated auxiliary engine and an external power source of a refrigeration truck; A battery that stores electric energy generated when the engine constituting the power supply is driven; An electric drive compressor that is driven by a generator-integrated auxiliary engine on the power supply device or an electric power applied from an external power source or a battery, and converts the sucked refrigerant into a high-temperature high-pressure refrigerant; A condenser that receives the high-temperature high-pressure refrigerant discharged from the electric drive compressor and converts it into a low-temperature high-pressure refrigerant; A receiver for temporarily storing the liquid refrigerant liquefied in the condenser; An expander for changing the low temperature high pressure refrigerant to a low temperature low pressure refrigerant by a pressure change; An evaporator that evaporates the low-temperature and low-pressure refrigerant to absorb ambient heat, thereby lowering the temperature inside the loading compartment; A defrosting device that removes frost formed on the surface of the evaporator; A liquid separator installed in a suction pipe between the evaporator and the electric drive compressor to separate the liquid refrigerant in the suction gas; A temperature sensor installed inside the loading dock of the refrigeration truck to sense the inside temperature of the loading dock and output an electric signal; It comprises a control unit for controlling the power supply in accordance with the electrical signal output from the temperature sensor.

In the present invention, the electric drive compressor is operated by a current applied from the battery or the generator-integrated auxiliary engine during daytime or vehicle operation to drive a cooling system; At night or during parking, the electric drive compressor is configured to be driven by the application of external power; The side of the refrigeration truck corresponding to the installation position of the external power source has a feature in which a connector for supplying electric energy from the ground power to the external power source is formed.

When the present invention is applied, the electric energy generated according to the driving of the engine during the operation of the refrigeration truck is stored in the battery, and then the compressor is driven with electric energy applied from the battery or electricity generated from the generator-integrated auxiliary engine Since the electric drive compressor can be driven by directly receiving energy or external power, fuel can be saved.

In addition, even when a load change (engine rpm change) occurs when the engine is driven, or when the engine is stopped or opened frequently or the engine is stopped, the temperature inside the refrigerator is always maintained within a certain range. When the engine of a refrigerator truck is stopped, the electric energy generated by the generator-integrated auxiliary engine or external power can be directly supplied to drive the electric-driven compressor, so the temperature inside the storage tank of the refrigerator truck is always maintained within a certain range. It is possible to prevent corruption of transport cargo and maintain freshness.

In addition, as the efficiency of energy utilization increases, it is possible to reduce the fuel cost, as well as to reduce the amount of fine dust and CO ₂ emissions through the reduction of fossil fuels.

1 is a block diagram showing the prior art.
2 is a block diagram showing an electric-driven cooling system of a refrigeration truck according to the present invention.
3 is a block diagram of a refrigeration truck to which the electric-driven cooling system according to the present invention is applied.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

2 and 3, the electric-driven cooling system 100 of the refrigerator truck according to the present invention includes a power supply 110, a battery B, an electric-driven compressor 120, a condenser 130, and a receiver 140, an expander, an evaporator for both cooling and storage, a defrosting device 170, a liquid separator 180, and a control unit 200.

The cooling cycle in the electric-driven cooling system 100 of the refrigeration truck according to the present invention is an electric-driven compressor 120 → condenser 130 → receiver 140 → expander → evaporator 160 → liquid separator 180 → One circulation structure that proceeds in the order of the compressor 120 is formed, and accordingly, the structure of the cooling system is simplified, thereby simplifying control and improving reliability.

In the present invention, the power supply device 110 is composed of an engine 111 of the refrigeration truck, a generator-integrated auxiliary engine 112, and an external power source 113.

In the case of the cooling system of the existing refrigeration truck, the cooling power of the engine was unstable depending on the operating state of the engine as the rotational power of the engine was converted to electric energy to obtain the driving force, and thus the temperature of the loading system could not be maintained.

In order to solve this problem, the present invention is provided with a battery (B) to enable the storage of electrical energy generated by the rotational power of the engine, the electric-driven compressor (120) with the electrical energy supplied from the battery (B) ), the generator-integrated auxiliary engine 112 and the external power source 113 are additionally provided so that the cooling system can be driven even when the engine 111 of the vehicle is stopped.

The external power source 113 is installed adjacent to the electric drive compressor 120 in the lower part of the loading rack, and a refrigeration truck corresponding to the installation position of the external power source 113 for electrical connection of the ground power and the external power source 113. It is preferable to install a connector 113a for electrical connection with land power on one side of the side.

In the present invention, the electric drive compressor 120 sucks and compresses a low-temperature, low-pressure gas refrigerant to increase the pressure to close the distance between molecules and increase the temperature, so that the condenser 130 can easily liquefy. That is, it serves to send the heat obtained while the refrigerant evaporates from the low heat source evaporator 160 to the high heat source condenser 130.

By the action of the electric drive compressor 120, the refrigerant circulates in the cooling system while repeating the evaporation and condensation process, and transports heat from low temperature to high temperature.

In this process, the amount of work of the electric drive compressor 120 is the same as the change in the enthal ratio of the inlet and outlet of the electric drive compressor 120, and the electric drive compressor 120 is preferably installed adjacent to the power supply 110. .

The electric drive compressor 120 of the present invention accumulates cold air in the evaporator 160 while operating by obtaining driving force from the battery B during operation, and at night or parking, the generator-integrated auxiliary engine 112 or external power source 113 ) To obtain a driving force to accumulate cold air in the evaporator 160.

The condenser 130 discharges heat of the high-temperature and high-pressure gas refrigerant discharged from the electric drive compressor 120 into air at room temperature to condense and liquefy it.

That is, the gas refrigerant condensed in the condenser 130 is deprived of the latent heat of condensation around it through cooling water or air. In this process, the amount of heat the gas refrigerant condensed is absorbed around through the cooling water or steam is at the entrance of the condenser 130. It is the same as the difference between the enthalpy of the gas refrigerant and the enthalpy of the liquid refrigerant at the outlet of the condenser 130.

In addition, this amount of heat is the value of the amount of heat absorbed by the refrigerant from the low-temperature object or space in the evaporator 160 and the amount of compression of the refrigerant received by the low-pressure refrigerant vapor in the electric drive compressor 120. The amount of condensation heat depends on the evaporation temperature and the condensation temperature, and even if the evaporation temperature is the same, if the condensation temperature is high, the amount of condensation increases, so the amount of condensation heat increases.

In addition, even when the condensation temperature is the same, when the evaporation temperature is low, the specific volume of the gas refrigerant sucked into the electric drive compressor 120 increases, so the amount of condensation increases as the amount of compression increases.

The receiver 140 is a container for temporarily storing the liquid refrigerant liquefied in the condenser 130 before sending it to the expander, and is formed as a cylindrical high pressure container. It also serves to recover the refrigerant in the system when repairing the cooling system or stopping it for a long time.

The expander throttles the liquid refrigerant from the receiver 140 to make it low temperature and low pressure, and then delivers it to the evaporator 160. Here, the throttling refers to a phenomenon in which the pressure decreases when the fluid passes through a narrow passage such as a nozzle or an orifice, without exchanging heat or work with the outside.

Theoretically, the expansion process is adiabatic, so there is no change in enthalpy. The expander 150 of the electric-driven cooling system 100 of the refrigeration truck according to the present invention is made of an expansion valve, and in a small refrigerator, a capillary can be mainly used instead of the expansion valve.

In addition, as the expansion valve, a temperature type, a pressure automatic type, a float type, a capillary type, etc. may be applied.

When the supply of the refrigerant from the expander 150 is insufficient, the desired evaporation temperature cannot be maintained, and the electric drive compressor 120 is overheated. If the supply of the refrigerant is too large, the liquid refrigerant overflows the evaporator 160 and the electric drive compressor Liquid refrigerant is sucked into the 120, and wet compression is performed in the electric drive compressor 120, and stable operation is difficult.

Therefore, the expander 150 should always be adjusted so that the combined cooling and evaporator 160 exerts the maximum effect.

The evaporator 160 is a low-temperature, low-pressure liquid refrigerant having a low temperature and pressure at the expander 150 absorbs latent heat of evaporation to cool, and the evaporation process in the evaporator 160 is an isostatic process and the difference in enthalpy evaporates. It becomes calorie.

Accordingly, the evaporator 160 has a good heat transfer coefficient, and should be manufactured in a structure in which heat is not sucked into the electric drive compressor 120.

In the present invention, the defrosting device 170 prevents frost caused by condensation on the surface of the evaporator 160. This is because when the frost is formed on the surface of the evaporator 160, the heat transmittance decreases and thus the refrigeration ability decreases. The defrosting device 170 operates when the time set by the timer is reached.

When defrosting is performed using the defrosting device 170, first, the power is cut to stop the operation of the electric drive compressor 120, and then the power is supplied to the defrosting device 170 to start the defrosting operation and a set time has elapsed. When the defrosting device 170 is stopped, the electric drive compressor 120 is operated by the power supply device 110.

The liquid separator 180 is installed in the suction pipe between the evaporator 160 and the electric drive compressor 120 to separate the liquid refrigerant in the suction gas, thereby preventing a liquid back to the electric drive compressor 120. By doing so, it protects the electric drive compressor 120 and additionally serves to prevent the liquid in the evaporator 160 from being disturbed.

The temperature sensor 190 detects the temperature inside the loading dock. The temperature sensor 190 should be able to detect whether the temperature inside the loading rack is above a set temperature or below a set temperature, as well as that the temperature is not balanced in the loading rack. It is also desirable to install it up and down at the back of the storage area.

The control unit 200 controls the cooling system to start by operating the power supply unit 110 when the temperature inside the storage area sensed by the temperature sensor 190 exceeds a preset temperature. In addition, when the storage is overcooled, the power supply device 110 is instructed to stop the cooling system to stop the operation.

The electric-driven cooling system 100 of the refrigeration truck of the present invention is an electric-driven compressor using a generator-integrated auxiliary engine 112 or an external power source 113 in the general case such as short-distance transportation, low-speed driving in the city, and stopping for rest. The electric drive compressor 120 may be driven by driving the 120 and obtaining electric power stored in the battery B after being generated from the engine 111 of the vehicle during long-distance transportation or heat extremes.

According to the present invention as described above, when the refrigeration truck is running, the electric energy generated by driving the engine 111 is stored in the battery B, and then the electric driving compressor is used as the electric energy applied from the battery B. It is possible to save fuel because it is possible to drive the electric drive compressor 120 by driving 120 or directly receiving electric energy generated from the generator-integrated auxiliary engine 112 or external power source 113.

In addition, even when a load change (engine rpm change) occurs when the engine is driven, or when the engine is stopped or opened frequently or the engine is stopped, the temperature inside the refrigerator is always maintained within a certain range. , Even when the engine of the refrigeration truck is stopped, the electric energy generated from the generator-integrated auxiliary engine 112 or external power 113 can be directly supplied to drive the electric driving compressor 120, so that the refrigeration truck is loaded (積載庫). ) Internal temperature is always maintained within a certain range to prevent corruption of transport cargo and maintain freshness.

In addition, according to the present invention, as the efficiency of energy utilization is increased, it is possible to reduce the fuel cost, as well as to reduce the amount of fine dust and CO ₂ emissions through the reduction of fossil fuels.

100: electric-driven cooling system of the refrigeration truck
110: power supply 111: engine
112: generator-integrated auxiliary engine 113: external power
113a: connector 120: electric drive compressor
130: condenser 140: receiver
150: expander 160: evaporator
170: defrosting device 180: liquid separator
190: temperature sensor 200: control unit
B: Battery.

Claims (2)

A power supply unit 110 consisting of an engine 111 of the refrigeration truck, a generator-integrated auxiliary engine 112, and an external power source 113;
A battery (B) that stores electric energy generated when the engine 111 constituting the power supply 110 is driven;
An electric drive compressor that is driven by electric energy applied from the generator-integrated auxiliary engine 112 or the external power source 113 or the battery B on the power supply device 110 to make the sucked refrigerant into a high-temperature high-pressure refrigerant ( 120) and;
A condenser 130 that receives the high-temperature high-pressure refrigerant discharged from the electric drive compressor 120 and converts it into a low-temperature high-pressure refrigerant;
A receiver 140 for temporarily storing the liquid refrigerant liquefied in the condenser 130;
An expander 150 for changing the low temperature high pressure refrigerant to a low temperature low pressure refrigerant by a pressure change;
An evaporator 160 that evaporates the low-temperature and low-pressure refrigerant to absorb ambient heat, thereby lowering the temperature inside the loading compartment;
A defrosting device 170 for removing frost formed on the surface of the evaporator 160;
A liquid separator 180 installed in a suction pipe between the evaporator 160 and the electric drive compressor 120 to separate the liquid refrigerant in the suction gas;
A temperature sensor 190 installed inside the loading dock of the refrigeration truck to sense the inside temperature of the loading dock and output an electric signal;
And a control unit (200) for controlling the power supply unit (110) according to an electric signal output from the temperature sensor (190). According to claim 1,
The electric drive compressor 120 operates by a current applied from the battery (B) or the generator-integrated auxiliary engine 112 during day or vehicle operation to drive a cooling system;
At night or parking, the electric drive compressor 120 is configured to be driven by the application of an external power source 113;
A connector 113a for supplying electric energy from the ground power to the external power 113 is formed on the side of the refrigeration truck corresponding to the installation position of the external power 113.

Images