JP2004156826A - Vehicular refrigerating equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the mounting performance of a refrigerating equipment for vehicle. <P>SOLUTION: The vehicular refrigerating equipment is provided with a bypass piping L2 bypassing a condenser 2 and expansion valves 3A and 3B and leading a refrigerant in a gaseous phase state discharged from a compressor 1 into evaporators 4A and 4B, a constant pressure expansion valve 11 decompressing the refrigerant communicating through the bypass piping L2 to an internal temperature saturation pressure of a cold insulation box or less, and a heat exchanger 15 heating the refrigerant communicating through the bypass piping L2 by using engine cooling water as a heat source. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigerating apparatus for a refrigerating car that can not only keep cold but also keep heat, and more particularly to a technique for improving the mountability to a vehicle.
[0002]
[Prior art]
In a refrigerating car that can not only keep cold but also keep warm, there is a hot water heating method as one of the methods for heating for keeping heat. According to this method, cooling water (although the temperature is about 90 ° C.) of a vehicle engine is introduced into a refrigerator, and the interior of the refrigerator is heated by radiating heat. , 2).
[0003]
Patent Document 1: Japanese Patent Application Laid-Open No. 08-099522 (paragraph [0018], FIGS. 1 and 5)
[Patent Document 2] JP-A-10-160321 (paragraph [0016], FIGS. 1 and 4)
[0004]
[Problems to be solved by the invention]
By the way, in the above-mentioned heating method, it is necessary to separately provide a pipe for introducing cooling water into the refrigerator, and it has been pointed out that the mounting of the refrigeration apparatus on the vehicle becomes complicated.
[0005]
The present invention has been made in view of the above circumstances, and has as its object to improve the mountability of a refrigeration system for a vehicle.
[0006]
[Means for Solving the Problems]
As means for solving the above problems, a vehicle refrigeration system having the following configuration is employed. That is, in the vehicle refrigeration apparatus according to the first aspect of the present invention, the refrigerant in the gaseous state discharged from the compressor is depressurized to a temperature not higher than the internal temperature saturation pressure of the space requiring temperature control, and is further heated and then heated. It is characterized by being introduced into.
[0007]
When the refrigerant in the gaseous phase discharged from the compressor is decompressed to or below the internal temperature saturation pressure of a space requiring temperature management (for example, a cool box in an embodiment described later) and then introduced into the evaporator, the introduced refrigerant is cooled. The heat is radiated without condensing in the evaporator, and the air in the space where the evaporator is installed is heated.
In the present invention, in the case where it is not possible to secure a sufficient amount of heat for heating the space even by the heat release without condensation as described above by the refrigerant in the gaseous phase, a larger amount of heat is obtained by additionally heating the depressurized refrigerant. It will be supplied to the space. Therefore, there is no need to separately provide a pipe for introducing cooling water into the storage unlike the conventional hot water cooling system.
[0008]
According to a second aspect of the present invention, there is provided the vehicle refrigeration apparatus according to the first aspect, wherein a bypass passage for introducing a refrigerant in a gaseous state discharged from the compressor into the evaporator by bypassing the condenser and the expansion valve. ,
Decompression means for decompressing the refrigerant flowing through the bypass to a temperature equal to or lower than a temperature saturation pressure in the refrigerator.
Opening and closing means for opening and closing the bypass path to interrupt the flow of the refrigerant,
Heating means for heating the refrigerant flowing through the bypass path.
[0009]
In the present invention, the normal cooling operation can be performed by switching the opening / closing means to cut off the refrigerant to the bypass path, and the heating operation without condensation as described above can be performed by flowing the refrigerant through the bypass path. By operating the opening / closing means, a cooling / heating operation is selected as required.
[0010]
According to a third aspect of the present invention, in the vehicle refrigeration apparatus according to the second aspect, the heating means uses cooling water of a vehicle traveling engine as a heat source.
[0011]
In the present invention, by using the engine cooling water as a heat source, which has a very large amount of heat but which would otherwise be discarded by a radiator or the like, the additional heat of the space can be reduced without requiring extra energy. I can do it.
[0012]
According to a fourth aspect of the present invention, there is provided a vehicle refrigeration apparatus according to the third aspect, further comprising an intermittent unit for intermittently supplying the cooling water to the heating unit.
[0013]
In the present invention, when a sufficient amount of heat can be secured by the heat radiation without the above-described condensation by the refrigerant in the gaseous state, excessive heating is prevented by cutting off the supply of the cooling water to the heating means. .
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 shows an outline of a vehicle refrigeration system mounted on a refrigeration vehicle having two cool boxes (however, it can perform not only cool but also warm). In the figure, reference numeral 1 denotes a compressor, 2 denotes a condenser, 3A and 3B denote expansion valves, 4A and 4B denote evaporators, 5 denotes an accumulator, and 6 denotes a receiver. Each device is connected via a refrigerant pipe L1 indicated by a thick solid line in the drawing to constitute a system for realizing a refrigeration cycle. The compressor 1 obtains a driving force from a vehicle running engine (or an engine separately provided for driving the compressor) EG described later.
[0015]
The two evaporators 4A and 4B are connected in parallel with the system together with the expansion valves 3A and 3B. One of the pipes branched in parallel and provided with the expansion valve 3A and the evaporator 4A is provided with an on-off valve 10A for interrupting the introduction of the refrigerant to the evaporator 4A, and the other pipe provided with the expansion valve 3B and the evaporator 4B. Is provided with an on-off valve 10B for interrupting the introduction of the refrigerant into the evaporator 4B. The evaporator 4A is arranged in one of the two cool boxes (hereinafter referred to as the front room A), and the evaporator 4B is arranged in the other of the two cool boxes (hereinafter referred to as the rear room B).
[0016]
A main refrigerant pipe L1 is a bypass pipe (indicated by a thin solid line in the figure) for introducing refrigerant discharged from the compressor 1 into the evaporators 4A, 4B by bypassing the condenser 2, the receiver 6, and the expansion valves 3A, 3B. L2 is connected. The tip of the bypass pipe L2 is branched into two, one of which is connected to the inlet side of the evaporator 4A, and the other is connected to the inlet side of the evaporator 4B. The one bypass pipe connected to the inlet side of the evaporator 4A is provided with an on-off valve 10C for interrupting the introduction of the refrigerant to the evaporator 4A, and the other bypass pipe connected to the inlet side of the evaporator 4B is connected to the other bypass pipe. , An on-off valve 10D for intermittently introducing refrigerant into the evaporator 4B is provided.
[0017]
In the bypass pipe L2, constant-pressure expansion is performed to reduce the refrigerant in the gaseous phase to a predetermined pressure (low pressure; PLset, the internal temperature saturation pressure of the cool box when placed in an overheated state, lower than PHset described later). A valve 11 is provided.
[0018]
On the high pressure side of the refrigerant pipe L1 (between the compressor 1 and the condenser 2), a discharge pressure regulating valve that opens when the discharge pressure of the compressor 1 exceeds a predetermined pressure (high pressure; PHset, higher than the PLset). 13 are provided. Thereby, the input of the compressor 1 can be increased and the heating capacity can be ensured.
[0019]
Check valves 14 for restricting the flow of the refrigerant in one direction are provided between the compressor 1 and the condenser 2, between the condenser 2 and the receiver 6, and on the refrigerant pipe L1 on the outlet side of the evaporators 4A and 4B. Have been.
[0020]
In the bypass pipe L2, heat for heating the refrigerant in the gaseous state depressurized by the constant-pressure expansion valve 11 by using the exhaust heat of the engine EG for driving the vehicle (or an engine separately provided for driving the compressor). An exchanger 15 is provided. More specifically, a part of the cooling water of the engine EG, which is originally circulated and supplied to the radiator 16A and the air conditioning heater core 16B, is circulated and supplied to the heat exchanger 15 through a separately provided cooling water pipe 17, and the cooling water is supplied. The refrigerant is heated by exchanging heat between the refrigerant and the depressurized refrigerant. Further, the cooling water pipe 17 is provided with an on-off valve 18 for interrupting the introduction of the cooling water to the heat exchanger 15 so that the heating of the refrigerant can be performed or interrupted as necessary.
[0021]
The heat exchanger 15 has a double-tube structure in which two tubes having different diameters are arranged inside and outside, and a refrigerant is passed through an inner tube and a cooling water is passed through a space between an inner tube and an outer tube to exchange heat. Heat exchangers are used.
[0022]
The operation of the vehicle refrigeration system configured as described above is described in [1. Cooling operation mode for both front and rear chambers], [2. Heating operation mode for both front and rear rooms], [3. Front-chamber cooling, rear-chamber heating operation mode], [4. Each mode of [front room heating, rear room cooling operation mode] will be described.
[1. When the cooling operation mode is selected for both the front and rear chambers, the following three modes are selectively executed. Each of the following modes (2) and (3) can be executed independently.
First, the on-off valves 10C and 10D are closed, and the on-off valves 10A and 10B are opened to cool the front chamber A and the rear chamber B in parallel (front and rear chamber parallel cooling mode; (1)). The refrigerant compressed by the compressor 1 is in a high-temperature and high-pressure gaseous phase, and the pressure becomes higher than PHset by closing the on-off valves 10C and 10D, and flows into the condenser 2 by opening the discharge pressure regulating valve 13. . The refrigerant flowing into the condenser 2 gives heat to the outdoor air and condenses itself to become a high-temperature and high-pressure liquid refrigerant. The condensed and liquefied refrigerant flows through the receiver 6, the on-off valves 10A and 10B, adiabatically expands in the process of flowing through the expansion valves 3A and 3B, becomes a low-temperature and low-pressure liquid refrigerant, and flows in parallel to the evaporators 4A and 4B. I do. The refrigerant flowing into the evaporators 4A and 4B cools the air in the front chamber A and the rear chamber B, and evaporates to become a low-temperature low-pressure gas refrigerant. The evaporated and vaporized refrigerant flows through the accumulator 5, is sucked into the compressor 1 and is compressed, and thereafter, the above process is repeated.
[0023]
Here, when the rear chamber B reaches the target set temperature, the on-off valves 10B, 10C, and 10D are closed, and the on-off valve 10A is opened to cool only the front chamber A, and the temperature management of the rear chamber B is stopped. (Cooling mode for front chamber only; (2)). The refrigerant compressed by the compressor 1 enters a high-temperature and high-pressure gas phase state, and flows into the condenser 2 by opening the discharge pressure regulating valve 13. The refrigerant flowing into the condenser 2 gives heat to the outdoor air and condenses itself to become a high-temperature and high-pressure liquid refrigerant. The condensed and liquefied refrigerant flows through the receiver 6, the on-off valve 10A, adiabatically expands in the process of flowing through the expansion valve 3A, and flows into the evaporator 4A as a low-temperature and low-pressure liquid refrigerant. The refrigerant flowing into the evaporator 4A cools the air in the front chamber A and evaporates to become a low-temperature low-pressure gas refrigerant. The evaporated and vaporized refrigerant flows through the accumulator 5, is sucked into the compressor 1 and is compressed, and thereafter, the above process is repeated.
[0024]
On the other hand, when the front chamber A reaches the target set temperature, the on-off valves 10A, 10C, and 10D are closed, the on-off valve 10B is opened to cool only the rear chamber B, and the temperature control for the front chamber A is stopped ( Cooling mode only in rear chamber; (3)). The refrigerant compressed by the compressor 1 enters a high-temperature and high-pressure gas phase state, and flows into the condenser 2 by opening the discharge pressure regulating valve 13. The refrigerant flowing into the condenser 2 gives heat to the outdoor air and condenses itself to become a high-temperature and high-pressure liquid refrigerant. The condensed and liquefied refrigerant flows through the receiver 6, the on-off valve 10B, and adiabatically expands in the process of flowing through the expansion valve 3B, and flows into the evaporator 4B as a low-temperature and low-pressure liquid refrigerant. The refrigerant flowing into the evaporator 4B cools the air in the rear chamber B, and evaporates to become a low-temperature low-pressure gas refrigerant. The evaporated and vaporized refrigerant flows through the accumulator 5, is sucked into the compressor 1 and is compressed, and thereafter, the above process is repeated.
[0025]
[2. When the heating operation mode is selected for both the front room and the rear room, the following three modes are selectively executed. The following modes (5) and (6) can be executed independently.
First, the on-off valves 10A and 10B are closed, and the on-off valves 10C and 10D are opened to heat the front chamber A and the rear chamber B in parallel (front and rear chamber parallel heating mode; (4)). The refrigerant compressed by the compressor 1 is in a gaseous state of high temperature and high pressure, and does not flow into the condenser 2 as long as the pressure is smaller than PHset, flows through the bypass pipe L2, and reaches PLset at the constant pressure expansion valve 11. The pressure is reduced while maintaining the gas phase. The depressurized refrigerant flows through the on-off valves 10C and 10D, and is introduced into the evaporators 4A and 4B in parallel. In the evaporators 4A and 4B, the introduced refrigerant in a gaseous state radiates heat without condensing, and heats the air in the front chamber A and the rear chamber B. The radiated refrigerant becomes a low-temperature and low-pressure gaseous phase, flows through the accumulator 5, is sucked into the compressor 1 and compressed, and thereafter repeats the above process.
[0026]
Here, when the rear chamber B reaches the target set temperature, the on-off valves 10A, 10B, 10D are closed, and the on-off valve 10C is opened to heat only the front chamber A, and the temperature control of the rear chamber B is stopped. (Heating mode only in front room; (5)). The refrigerant compressed by the compressor 1 is in a gaseous state of high temperature and high pressure, and does not flow into the condenser 2 as long as the pressure is smaller than PHset, flows through the bypass pipe L2, and reaches PLset at the constant pressure expansion valve 11. The pressure is reduced while maintaining the gas phase. The depressurized refrigerant flows through the on-off valve 10C and is introduced into the evaporator 4A. In the evaporator 4A, the introduced refrigerant in the gaseous state radiates heat without condensing, and heats the air in the front chamber A. The radiated refrigerant becomes a low-temperature and low-pressure gaseous phase, flows through the accumulator 5, is sucked into the compressor 1 and compressed, and thereafter repeats the above process.
[0027]
On the other hand, when the front chamber A reaches the target set temperature, the on-off valves 10A, 10B, and 10C are closed, and the on-off valve 10D is opened to heat only the rear chamber B, and the temperature control of the front chamber A is stopped ( Heating mode only in rear room; (6)). The refrigerant compressed by the compressor 1 is in a gaseous state of high temperature and high pressure, and does not flow into the condenser 2 as long as the pressure is smaller than PHset, flows through the bypass pipe L2, and reaches PLset at the constant pressure expansion valve 11. The pressure is reduced while maintaining the gas phase. The depressurized refrigerant flows through the on-off valve 10D and is introduced into the evaporator 4B. In the evaporator 4B, the introduced refrigerant in the gaseous phase radiates heat without condensing, and heats the air in the rear chamber B. The radiated refrigerant becomes a low-temperature and low-pressure gaseous phase, flows through the accumulator 5, is sucked into the compressor 1 and compressed, and thereafter repeats the above process.
[0028]
In each of the above modes (4) to (6), the heat of each chamber can also be heated by the heat release without condensing by the refrigerant in the gaseous state (hereinafter referred to as heat release by the non-condensed hot gas heating cycle). When a sufficient amount of heat cannot be secured, the on-off valve 18 is opened, and the cooling water from which heat of the engine EG has been taken is introduced into the heat exchanger 15. When the refrigerant is introduced into the heat exchanger 15, the refrigerant in the gaseous phase flowing through the bypass pipe L2 is additionally heated, so that a larger amount of heat is supplied to each chamber. If a sufficient amount of heat can be ensured by the heat radiation of the non-condensing hot gas heating cycle, excessive heating can be prevented by closing the on-off valve 18.
[0029]
[3. When the front room cooling and rear room heating operation mode is selected, the above-mentioned [front room only cooling mode; [2]] and the above described [back room only heating mode; [6]] are alternately executed. become. Also in this case, in the mode of (6), if a sufficient amount of heat for heating the rear chamber B cannot be secured, a larger amount of heat is supplied to the rear chamber B by introducing cooling water into the heat exchanger 15 in the manner described above. Is done.
[0030]
[4. When the front room heating and rear room cooling operation mode is selected, the above-mentioned [front room only heating mode; [5]] and the above-mentioned [rear room only cooling mode; [3]] are executed alternately. become. Also in this case, if the amount of heat sufficient for heating the anterior chamber A cannot be secured in the mode of (5), a larger amount of heat is supplied to the anterior chamber A by introducing cooling water into the heat exchanger 15 in the manner described above. Is done.
[0031]
FIG. 2 shows a state in which the vehicle refrigeration device having the above configuration is mounted on a truck. As shown in FIG. 2, in the present embodiment, a cooling water pipe 17 for circulating engine cooling water is provided between the driver's seat 20 and the van 21 and provided along the back wall of the driver's seat 20 outside the refrigerator. In this configuration, the heat exchanger 15 is arranged only around the heat exchanger 15 to be provided, and realizes a configuration in which heat can be exchanged while the influence of the hot water heat loss with the bypass pipe L2 before branching to the evaporators 4A and 4B is small. By adopting such a configuration, for example, as in the refrigeration systems for vehicles described in Patent Documents 1 and 2, the air conditioning unit for the front room at the front of the van and the air conditioning unit for the rear room at the rear of the van It is not necessary to install a cooling water pipe, and a configuration that is extremely excellent in workability when mounting a refrigeration system that combines heating using a hot water heat source and hot gas heating in a vehicle, that is, excellent in bodyworkability it can.
[0032]
In addition, if the on / off valves 10A to 10D are operated, the cooling / heating operation is selected as required, so that the operation mode can be easily switched according to the required load. In addition, by using the engine cooling water as a heat source, which has a very large amount of heat but is almost always discarded by the radiator 16A or the like, the additional heat of each room is not required. Can be quickly and efficiently heated in the refrigerator which has been shifted to the heat-retaining state. Further, when a sufficient amount of heat can be secured by the heat radiation of the non-condensed hot gas heating cycle, excessive heating is prevented by cutting off the supply of the cooling water to the heat exchanger 15. A heating operation can be performed.
[0033]
By the way, in the present embodiment, the engine cooling water is used as a heat source for heating the refrigerant, but an auxiliary device (for example, a viscous heater) for generating a heat source may be separately mounted as a heating means without using this. Absent.
[0034]
【The invention's effect】
As described above, according to the present invention, even by the heat radiation of the non-condensed hot gas heating cycle, if it is not possible to secure a sufficient amount of heat for heating the space requiring temperature control, by additionally heating the depressurized refrigerant. , A larger amount of heat will be supplied to the space. Therefore, unlike the conventional hot water cooling system, it is not necessary to separately provide a pipe for introducing the cooling water into the storage, so that the mountability of the refrigeration system for the vehicle can be significantly improved.
[0035]
According to the present invention, a normal cooling operation can be performed by switching the opening / closing means to cut off the refrigerant to the bypass, and a heating operation without condensation as described above can be performed by flowing the refrigerant through the bypass. In addition, if the opening / closing means is operated, the cooling / heating operation is selected as needed, so that the operation mode can be easily switched according to the required load.
[0036]
According to the present invention, the use of engine cooling water as a heat source, which has a very large amount of heat but would otherwise be discarded in a radiator or the like, allows the additional heat of the cool box without requiring extra energy. Can be quickly and efficiently heated in the refrigerator which has been shifted to the heat-retaining state.
[0037]
According to the present invention, when a sufficient amount of heat can be ensured by the heat radiation of the non-condensing hot gas heating cycle, by cutting off the supply of the cooling water to the heating means, excessive heating is prevented, and the load is commensurate with the load. Appropriate heating operation can be performed.
[Brief description of the drawings]
FIG. 1 is a view showing an embodiment of the present invention, and is a view showing an outline of a vehicle refrigeration apparatus having two cool boxes.
FIG. 2 is an explanatory view showing a state where the vehicle refrigeration apparatus of FIG. 1 is mounted on a truck.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3A, 3B Expansion valve 4A, 4B Evaporator 5 Accumulator 6 Receiver 10C, 10D Opening / closing valve (opening / closing means)
11 Constant pressure expansion valve (pressure reducing means)
15 Heat exchanger (heating means)
17 Cooling water piping 18 On-off valve (intermittent means)
L1 Refrigerant pipe L2 Bypass pipe (bypass path)
EG engine

Claims (4)

A refrigeration system for a vehicle, wherein a refrigerant in a gaseous state discharged from a compressor is depressurized to an internal temperature saturation pressure or lower in a space requiring temperature control, heated, and then introduced into an evaporator. A bypass for introducing a refrigerant in a gaseous state discharged from the compressor to the evaporator, bypassing the condenser and the expansion valve,
Decompression means for decompressing the refrigerant flowing through the bypass to a temperature equal to or lower than a temperature saturation pressure in the refrigerator.
Opening and closing means for opening and closing the bypass path to interrupt the flow of the refrigerant,
Heating means for heating the refrigerant flowing through the bypass passage. 3. The refrigeration system for a vehicle according to claim 2, wherein said heating means uses cooling water of a vehicle driving engine as a heat source. The vehicle refrigeration apparatus according to claim 3, further comprising an intermittent unit for intermittently supplying the cooling water to the heating unit.

Images