JPS5812819A - Vehicle refrigerator - Google Patents

Abstract

PURPOSE:To aim at enhancing refrigerating effect irrespective of waste heat capacity in a vehicle refrigerator utilizing waste heat, by combining an expansion unit, an engine and a compressor, power-transmissibly, so that they are selectively driven in dependence upon waste heat and refrigerating load. CONSTITUTION:Operating fluid, in a Rankine cycle 10, heated by cooling water from a radiator 3 is evaporated in a steam generator 14 and then, flows into an expansion unit 11 for rotating the latter. The steam from the expansion unit 11 flows into a heat recovering heat exchanger 15 and a condenser 12 for condensation, and is circulated. Rotating power of the expansion unit 11 is transmitted to a compressor shaft 37 in a refrigerating cycle 20 through a clutch 34 for driving a compressor 21. In this state, if the capacity of engine waste heat is extremely little, power transmission between the expansion unit 11 and an engine shaft 2 and between the expansion unit 11 and the compressor 21 is disconnected so that the compressor 21 is driven by the engine alone. Thus, the power transmission is switched in dependence upon waste heat or refrigerating load, thereby refrigerating effect and waste heat recovering effect are enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigerator for a vehicle, and more particularly to a refrigerator that drives a refrigeration cycle with a heat engine that utilizes waste heat from an automobile to obtain a refrigeration effect.

BACKGROUND ART Conventionally, as refrigerators that utilize waste heat from automobiles, rank/engine-driven refrigerators and absorption refrigerators have been proposed. However, these refrigerators have the disadvantage that they cannot provide a sufficient refrigeration effect when the load on the vehicle is small, that is, when the amount of waste heat is small.

In view of the above, an object of the present invention is to provide a refrigerator for a vehicle that can obtain a desired refrigeration effect regardless of the amount of waste heat and can recover waste heat as power when the refrigeration load is small. It is.

To achieve the above object, the present invention includes a known Rankine cycle, a refrigeration cycle, and an engine, and connects the expander of the Rankine cycle and the compressor of the refrigeration cycle via a clutch, and By linking the machine and engine through power transmission means, the compressor is driven through the engine when the amount of waste heat is low, and the output of the expander is recovered to the engine when the amount of waste heat is large. Out.

An embodiment of the present invention will be described below with reference to the drawings.

1 is an engine, 2 is a shaft of the engine 1, 3 is a fan installed at the tip of the shaft 2 so as to face the radiator 4, 1
1 is an expander, 12 is a Rankine cycle condenser installed in front of the radiator 4, 13' is a refrigerant pump installed between the condenser 12 and the heat recovery exchanger 15, and 14 is a refrigerant pump installed in the radiator 4. The installed steam generator constitutes a Rankine cycle 10 by these devices 11 to 15 and piping connecting the devices 11 to 15.

21 is a refrigerant compressor, a refrigeration cycle condenser installed in front of the 22-digit radiator 4, 23 is an expansion means, 24 is an evaporator, 25 is a fan for the evaporator 24, and these devices 21
25 and the piping connecting the devices 21 to 25 constitute a refrigeration cycle 2o.

The expander 11 of the Rankine cycle 1o, the compressor 21 of the refrigeration cycle 20, and the engine 1 are constructed so that they can be engaged and detached by the following mechanism. That is, the shaft 31 of the expander 11 is connected to a power take-off electromagnetic clutch 32 mounted on this shaft 31, and a power extraction electromagnetic clutch 32 mounted on the engine shaft 2.
'L is connected to the engine 1 via a pulley 33 and a belt 38.

The electromagnetic clutch 32 is connected to the expander 1 as shown in FIG.
a stator 32a that is fixed to one fixed member 11a and has a built-in coil 32b; a rotor 32C that is rotatably fitted to the fixed member 11a and has a belt groove;
A disk 32d fixed to the expander shaft 31 and a disk member 3 attached to the disk 32d via a spring.
2e. When the coil 32b in the stator 32a is energized, the disk member 32e is attracted to the rotor 32C by electromagnetic force.
Since C and the disk 32d, that is, the expander shaft 31 are integrally connected, the expander 11 and the engine 1 are dynamically connected.

On the refrigeration cycle 20 side, the compressor 21 includes a power introduction electromagnetic clutch 35 attached to the compressor shaft 37, a pulley 36 attached to the engine shaft 2, and a belt 39.
It is linked to engine 1 via n. The electromagnetic clutch 35 has the same structure as the electromagnetic clutch 32 shown in FIG.

The expander shaft 31 and compressor shaft 37 are connected via an electromagnetic clutch 34. As shown in FIG. 3, the clutch 34 is fixed to a fixed member 34f and has a coil 34b.
A stator 34a with a built-in rotor 34C, a rotor 34C attached to the expander shaft 31, a disk 34d attached to the compressor shaft 37, and a disk member 34e attached to the disk 34d via a spring. . When the coil 34b in the stator 34a is energized, the disk member 34e is attracted to the rotor 34C by electromagnetic force, so that the expander shaft 31 and the compressor shaft 37 are integrally coupled.

In this embodiment described above, the condensers 12 and 22 of the Rankincike/I/'10 and the refrigeration cycle 20 are cooled by the radiator fan 3 disposed in front of the radiator 4 and the air flow accompanying the vehicle running. However, the condenser 12.22 is appropriately placed in an appropriate space of the vehicle,
Cooling may be provided by a separate fan. Furthermore, although the steam generator 14 of the Rankine cycle 10 is disposed within the radiator 4, the steam generator may be disposed at an appropriate location to exchange heat with the engine cooling medium.

Furthermore, although engine cooling water was considered as engine waste heat, exhaust gas may also be considered. In this case, the steam generator 14 may be provided in a passage through which exhaust gas flows, and heat may be recovered from the exhaust gas.

Next, the operation of this embodiment configured as described above will be explained.

The working fluid of the Rankine cycle 10 heated by the engine cooling water in the radiator 3 becomes high-temperature, high-pressure steam in the steam generator 14 and flows into the expander 11 . On this occasion,
The steam releases energy while being expanded under reduced pressure, and is output as rotational power of the expander 11. The low-pressure steam discharged from the expander 11 flows into the condenser 12 via the heat recovery heat exchanger 15, where it is cooled by the radiator fan 3 and the air flow accompanying the vehicle's travel, and is condensed and liquefied. do.

This liquefied working fluid is pressurized by the refrigerant pump 13, and is further sent to the steam generator 14 via the heat recovery heat exchanger 15 to complete the Rankine cycle 10.

The low-pressure fluid discharged from the expander 11 has a low pressure level but is quenched at a high temperature, so it is sent under pressure by the refrigerant pump 13 to the steam generator 14 via the heat exchanger 15, where it is heated. By using the sensible heat of the heat exchanger 15 to preheat the liquid fluid, the thermal efficiency of the cycle can be improved. However, in cases where space limitations are severe, there is no risk that the basic effect will be lost even if the heat exchanger 15 is omitted.

The rotational power extracted from the expander 11 in this way is
The compressor shaft 37 of the refrigeration cycle 20 via the clutch 34
The compressor 21 is driven by the signal transmitted to it. Due to this drive, the low-temperature, low-pressure refrigerant that flows out of the evaporator 24 of the refrigeration cycle 20 and flows into the compressor 21 is compressed and becomes a high-temperature, high-pressure gas refrigerant and is sent to the condenser 22. The gas refrigerant is cooled by the radiator fan 3 and the air flow accompanying the running of the vehicle, condensed and liquefied, and then sent to the expansion means 23. In this expansion means 23, the high pressure liquid refrigerant is adiabatically expanded under reduced pressure to become a low temperature, low pressure, gas-liquid multiphase refrigerant, which is transferred to the evaporator 2.
Sent to 4. In the evaporator 24, the gas-liquid multiphase refrigerant is vaporized and becomes a low-temperature, low-pressure gaseous refrigerant, which is sucked into the compressor 21 again to complete the refrigeration cycle 20.

The air cooled by the evaporator 24 is treated by suitable means.
It is sent to a desired location and subjected to cooling.

As mentioned above, the waste heat of engine 1 is the Rankine cycle 1
Since the rotational power of the expander 11 is converted to zero, the shaft 31 is rotated. This rotation of the shaft 31 causes the electromagnetic clutch 3
4 and shaft 37 to connect the compressor 2 of the refrigeration cycle 20.
1 is driven to produce a refrigeration effect.

Next, to explain the basic control circuit of the Mumei Example with reference to Fig. 4, A is the t source, B is the ground%, I JC is the switch, 32b is the electromagnetic clutch, the coil of Tsuchi 32, and 34b is the electromagnetic clutch. 34 coil, 35b is electromagnetic clutch 35
The coil is used.

When the switches a, b, and c are turned on, the coils 32b corresponding to the switches a and c are turned on.

34b and 35b are energized and each clutch 32°34.3
5 are respectively excited, the expander 11 and the engine shaft 2, the expander 11 and the compressor 21, and the engine shaft 2 and the compressor 2
1 are engaged with each other in a male-force manner.

(I) When the amount of engine waste heat is extremely small, the amount of waste heat is small when the engine output is extremely small, such as when the vehicle is in an idling state or when starting. in this case,
Switches a and b are turned off, and switch C is turned on. Expander 11 and engine shaft 2 and expander 11 and compressor 21
Since the compressor 21 and the engine shaft 2 are engaged with each other, the compressor 1 is driven exclusively by the output of the engine 1.

■ If there is waste heat, but it is insufficient to drive the compressor of the refrigeration cycle, in this case, turn off switch a and turn off switch b.

Set Ct-on. Since the expander 11 and the compressor 21 are dynamically engaged, the compressor 21 is driven by both the output of the Rankine cycle 10 and the output of the engine 1.

■ When the amount of waste heat equivalent to driving the compressor of the refrigeration cycle can be obtained, in this case, switches a and C are turned off and switch b is turned on. The compressor 21 of the refrigeration cycle 20 is dynamically engaged with the expander 11 of the Rankine cycle 10, and the expander 1
1 output only.

If a sufficient amount of waste heat is observed, In this case, switch C is turned off.

Turn on b. The expander 11 is dynamically connected to the engine shaft 2 and the compressor 21, and surplus power of the driving force of the compressor 21 is regenerated to the engine 1.

M If there is no refrigeration load, In this case, switch a is turned on and switch b is turned on.

Turn C off. The expander 11 is dynamically engaged with the engine shaft 2, and all output of the expander 11 is regenerated to the engine 1.

Various methods can be used to automatically perform the above control, and an example of the control circuit is shown in FIG. In the same figure, a to C
is the switch shown in Fig. 4, e is the amplifier, f is the arithmetic circuit,
g is a single-chamber temperature sensor, h is a sensor that detects the opening time of the engine's fuel injection valve, j is a power supply, and k is a ground.

In a control circuit having such a configuration, the amount of waste heat is calculated by integrating the open time of the fuel injector to calculate the amount of fuel consumed, and the calculation circuit is configured to calculate the amount of waste heat using a program prepared in advance. There is. Therefore, the temperature of the air-conditioned space is detected by the temperature sensor g, and based on this detected temperature, it is determined whether the compressor is on or off, and the coils of the electromagnetic clutches 32b, 34b, and 35b are electromagnetically activated depending on the amount of waste heat. Automatically control switches A and C by selectively turning them on and off.

As explained above, according to this invention, the air conditioner can be operated regardless of the amount of engine waste heat, so not only is a comfortable product term always available, but also waste heat can be used as power when air conditioning is not required. This can improve the overall thermal efficiency of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an embodiment of the vehicle refrigerator of the present invention, Figs. 2 and 3 are sectional views of the power transmission/delivery means of the same embodiment, and Fig. 4 is the basics of the power transmission means. FIG. 5 is a control circuit diagram for operating the switch of FIG. 4. 1... Engine, 10... Rankine cycle, 11
... Expander, 12.22...# width container, 13... Refrigerant pump, 14... Steam generator, 20... Refrigeration cycle, 21... Compressor, 23... Decompression means, 24.
...Evaporator, 32°34.35...Electromagnetic clutch. 'M 1 (2) 2nd rfU 320L32c

Claims (1)

[Claims] A Rankine cycle consisting of an expander, a #condenser, a refrigerant pump, and a steam generator, a compressor, and a condenser. The system includes a refrigeration cycle consisting of an expansion means and an evaporator, and an engine, and the expander, the engine, and the compressor are interconnected through a power transmission means, and depending on the amount of engine waste heat and refrigeration load. A vehicular refrigerator characterized in that an expander, an engine, and a compressor are selectively engaged and disengaged, respectively.