JP5535510B2 - Refrigeration equipment for land transportation - Google Patents

Description

  The present invention relates to a refrigeration apparatus for land transportation.

A refrigeration system for land transportation is installed in a vehicle or the like that is installed in a cargo room (van) such as a truck, cools or heats the inside, and transports the loaded cargo at a desired temperature. .
The refrigeration equipment for land transportation includes a direct connection type that uses the output of a vehicle travel engine for driving a compressor for compressing refrigerant, and a sub-engine system that includes a dedicated drive source (such as an engine or an electric motor).
In addition, the refrigeration system for land transportation is connected to a plurality of (usually 2 to 3) evaporator units for one compressor so that different transportation temperatures can be created for each of a plurality of sections. There is.

The refrigeration equipment for land transportation is, for example, frozen food that is cooled and transported to about −30 ° C., chilled food that is transported while maintaining about −1 to 5 ° C., and transported while maintaining the inside temperature of about 2 to 30 ° It is used in a wide set temperature range such as products to be used. In this respect, it is different from a general air conditioner having a set temperature range of about 20 to 30 ° C.
In order to cover such a wide set temperature range, it is necessary to provide both cooling and heating functions based on the relationship between the outside air temperature and the inside set temperature.
In a multi-type refrigeration system for land transportation, chilled foods held at about -1 to 5 ° C and, for example, lunch boxes held at about 20 ° C are transported and transported by a single vehicle. There is. In this case, a cooling and heating mixed operation is required in which a cooling operation is performed in a section loaded with chilled food, and a heating operation is performed in a section loaded with a lunch box or the like.

Conventionally, in a refrigeration system for land transportation, hot water heating using engine cooling water has been often used as an operation method for increasing the temperature in the warehouse.
In recent years, the efficiency of the engine has been remarkably improved, so the amount of heat that can be extracted from the cooling water has been reduced. For this reason, when cooling water is used for heating the refrigeration system for land transportation, for example, the amount of heat to be turned to the cab (cabin) side is reduced, and the driver's working environment is deteriorated. In addition, in order to bring the cooling water to the refrigeration system for land transportation, it is necessary to modify the vehicle, and the manufacturing cost increases due to the bodywork cost. For this reason, it is required that the refrigeration apparatus for land transportation itself has a heating function.

  As what is heated by the refrigeration apparatus for land transportation itself, for example, as shown in Patent Document 1, a high-temperature and high-pressure gas refrigerant (hot gas) discharged from a compressor bypasses the external heat exchanger and is inside the warehouse. A hot gas bypass heating system that is circulated in a heat exchanger is generally used.

JP 2003-269805 A

By the way, as shown in Patent Document 1, the hot gas bypass heating method has a small heating capacity and low energy efficiency because the hot gas changes the work of the compressor into heat.
In addition, if the efficiency of the compressor is improved, the heating capacity will be further reduced, so a compressor with a larger capacity than necessary will be used to secure the heating capacity, or the use of an efficient compressor will be restricted. there's a possibility that.
Furthermore, it is difficult to apply to the operation where cooling and heating are mixed in a structurally multi-type refrigeration system for land transportation.

When heat pump heating is generally used in an air conditioner, the heating capacity and energy efficiency problems can be solved.
However, the following problems remain in heat pump heating, which is common in air conditioners.
That is, for example, in the reverse cycle method in which the cooling operation and the heating operation are switched, the cooling / heating mixed operation cannot be performed.
Further, in the case where the direction of refrigerant flow is changed by the four-way valve, the switching operation becomes unstable when the four-way valve is close to the minimum operating pressure necessary for performing the switching operation by the pilot pressure.
For example, in a directly-coupled land transport refrigeration system in which the compressor is driven by a vehicle engine, the rotation speed of the compressor corresponds to the rotation speed of the vehicle engine and cannot be controlled on the land transport refrigeration apparatus side. When the rotational speed of the vehicle engine decreases according to the driving situation, the capacity of the compressor decreases, the differential pressure between the compressor outlet and the inlet becomes small (low differential pressure), and the circulating refrigerant amount is small Become. If this low differential pressure becomes smaller than the minimum operating pressure of the four-way valve, it is possible that switching cannot be performed. In addition, since the land transport refrigeration system is also affected by the running vibration of the vehicle, it is difficult to apply the method of switching by the four-way valve to the direct connection type land transport refrigeration apparatus.

  The present invention has been made in view of such circumstances, and provides a refrigeration apparatus for land transportation that can obtain a large heating capacity efficiently and can stably perform various operations including a cooling and heating mixed operation. The purpose is to do.

The present invention employs the following means in order to solve the above problems.
That is, the refrigeration apparatus for land transportation according to the present invention includes a compressor driven by a power source, a plurality of indoor heat exchangers installed for each of a plurality of refrigeration sections in which a cargo compartment is divided, and the outside of the cargo compartment. An outdoor heat exchanger installed, and a refrigeration apparatus for land transportation capable of creating a plurality of different transport temperatures for each refrigeration section, the discharge side of the compressor, the indoor heat exchanger, and the outdoor A plurality of high-pressure gas pipes connected in parallel to one end of the pipe line of the heat exchanger, a plurality of high-pressure on-off valves that open and close each of the high-pressure gas pipes, and a downstream side of the high-pressure on-off valve in each of the high-pressure gas pipes A plurality of low-pressure gas pipes that connect the position and the suction side of the compressor in parallel; a plurality of low-pressure on-off valves that open and close the low-pressure gas pipes; and one end of the indoor heat exchanger and the outdoor heat exchanger Connected to the other end of the pipe and the other end A plurality of throttle pipes that are joined together, a plurality of throttle mechanisms that are installed in the respective throttle pipes and have a pressure reducing function that can be opened and closed, and are provided in each of the throttle pipes so as to bypass the throttle mechanism, And a plurality of bypass pipes having check valves for preventing inflow into the indoor heat exchanger and the outdoor heat exchanger.

One end of the pipe line of the outdoor heat exchanger is connected to the discharge side of the compressor by a high-pressure gas pipe having a high-pressure on-off valve, and is connected to the suction side of the compressor by a low-pressure gas pipe having a low-pressure on-off valve. Since the low-pressure gas pipe is connected to the high-pressure gas pipe on the downstream side of the high-pressure on-off valve, the outdoor heat exchanger is discharged from the compressor to one end of the pipe by switching the high-pressure on-off valve and the low-pressure on-off valve. The high-temperature and high-pressure refrigerant gas can be received and sent out from the other end side, and the refrigerant received from the other end side can be supplied from the one end side to the suction side of the compressor.
A throttle pipe having a throttle mechanism that can be opened and closed is connected to the other end of the pipe line of the outdoor heat exchanger, and a bypass pipe having a check valve that prevents inflow to the outdoor heat exchanger side is throttled in the throttle pipe. Since it is provided so as to bypass the mechanism, when the throttle mechanism is closed, the refrigerant from the outdoor heat exchanger is supplied to the other end of the throttle pipe via the bypass pipe. When the throttle mechanism is opened, the refrigerant flowing from the other end side of the throttle pipe is decompressed by the throttle mechanism and supplied to the other end of the pipe line of the outdoor heat exchanger.

Therefore, when the high-pressure on-off valve is opened and the low-pressure on-off valve and the throttle mechanism are closed, the high-temperature and high-pressure refrigerant gas discharged from the compressor flows into the outdoor heat exchanger, passes through the pipeline, and is bypassed. It will be supplied to the end of the throttle pipe.
If it does in this way, since the high-temperature / high-pressure refrigerant gas passes through the pipe line of the outdoor heat exchanger, the pipe line can be defrosted (defrost operation).
Further, if heat exchange is performed between the high-temperature and high-pressure refrigerant gas passing through the pipe and the outdoor air, the refrigerant gas is cooled by the outdoor air and condensed to be a liquid refrigerant. That is, the outdoor heat exchanger functions as a refrigerant condenser (condenser).
At this time, since the liquid refrigerant passes through the bypass pipe bypassing the throttle mechanism, it is not decompressed by the throttle mechanism. As a result, the liquid state can be reliably maintained.
On the other hand, each of the plurality of indoor heat exchangers is provided with a high-pressure gas pipe, a low-pressure gas pipe, a throttle pipe and a bypass pipe each having the same configuration as the outdoor heat exchanger, and they are attached in parallel. The same operation as that of the outdoor heat exchanger can be performed. In other words, the plurality of indoor heat exchangers and outdoor heat exchangers can be used independently as condensers and can perform defrost operation.

Since the other ends of the throttle pipes connected to the plurality of indoor heat exchangers and the outdoor heat exchanger are merged, among the plurality of indoor heat exchangers and outdoor heat exchangers, those that are not used as condensers, for example The indoor heat exchanger that functions as a condenser when the throttle mechanism is opened, for example, the indoor refrigerant in a state where the liquid refrigerant supplied from the outdoor heat exchanger is decompressed through the throttle pipe having the throttle mechanism opened. The exchanger flows into the other end of the pipeline. At this time, if the high pressure on-off valve is closed and the low pressure on-off valve is opened, the refrigerant from the indoor heat exchanger flows into the suction side of the compressor.
Since the liquid refrigerant is cooled, if heat is exchanged with the air in the refrigeration compartment (room air), the liquid refrigerant is warmed by the air in the refrigeration compartment and evaporated to become a low-pressure refrigerant gas. On the other hand, the air in the freezing compartment is cooled because it takes heat of vaporization when the liquid refrigerant evaporates. That is, the plurality of indoor heat exchangers and outdoor heat exchangers function independently as refrigerant heat absorbers (evaporators).
The plurality of indoor heat exchangers and outdoor heat exchangers can be used independently as heat absorbers.

If the indoor heat exchanger is used as a condenser, the air in the freezing compartment is heated, so that a heating operation can be performed. Since this heating operation is heat pump heating, it is efficient and can provide a large heating capacity.
On the other hand, if the indoor heat exchanger is used as a heat absorber as described above, the air in the freezing compartment is cooled, so that a cooling operation can be performed. Further, if heat exchange with the air in the freezing compartment is not performed, the indoor heat exchanger can be defrosted.
As described above, since the plurality of indoor heat exchangers and outdoor heat exchangers can be used independently as condensers or heat absorbers, various operations can be performed.
For example, if some indoor heat exchangers are used as condensers and the other part are used as heat absorbers, the cooling / heating mixing operation can be performed only with the indoor heat exchangers. If the outdoor heat exchanger is stopped, heat is exchanged between the refrigeration compartments, so that the efficiency of cooling or heating can be significantly improved.
In addition, if some indoor heat exchangers are in the same state as the condenser and heat exchange with outdoor air or refrigeration compartment air is not performed, other indoor heat exchangers are in cooling operation or heating operation The defrosting operation can be performed.
Furthermore, if an outdoor heat exchanger is used as a condenser or a heat absorber and a plurality of indoor heat exchangers are used as a heat absorber or a condenser, a plurality of refrigeration sections can be simultaneously cooled or heated.

Since the high-pressure on-off valve, the low-pressure on-off valve, and the throttle mechanism only perform a simple opening / closing operation, stable and reliable switching can be performed under any conditions.
Thereby, it can apply also to the direct connection type refrigeration apparatus for land transport in which the state of a compressor may change a lot.

According to the present invention, since the plurality of indoor heat exchangers and outdoor heat exchangers can be used independently as condensers or heat absorbers, various operations can be performed.
Since the heating operation using the indoor heat exchanger as the condenser is heat pump heating, it is efficient and can obtain a large heating capacity.
Since the high-pressure on-off valve, low-pressure on-off valve, and throttle mechanism only perform simple opening / closing operations, they can also be applied to directly connected land transport refrigeration equipment in which the compressor state may fluctuate greatly. .

It is a block diagram which shows schematic structure of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention. It is a block diagram which shows one driving | running state of the refrigeration apparatus for land transport concerning one Embodiment of this invention.

Hereinafter, a refrigeration apparatus 1 for land transportation according to an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a block diagram illustrating a schematic configuration of a refrigeration apparatus 1 for land transportation according to the present embodiment.
The refrigeration apparatus 1 for land transportation is installed in a luggage compartment (van) mounted on a vehicle loading platform such as a truck, and cools and heats a cargo compartment divided into a plurality of, for example, two refrigeration compartments to different temperatures. Because it is possible, it is called multitype.

A cargo room that forms a cooling space is mounted on the truck bed. This luggage compartment is divided into two refrigeration compartments composed of the first cargo compartment 2A and the second cargo compartment 2B by providing a partition wall in the internal space.
The refrigeration apparatus 1 for land transport includes a compressor 3 that compresses refrigerant and discharges it as a high-pressure gas refrigerant, a power source 4 such as an engine that drives the compressor 3, and outdoor heat that is installed outside the cargo compartment. An exchanger 6 and indoor heat exchangers 7 and 8 installed in the cargo compartments 2A and 2B are provided.

As the compressor 3, for example, an open scroll compressor having a small size and high performance is used. The format of the compressor 3 is not particularly limited.
As the power source 4 such as an engine, there is a dedicated power source 4 that is independent from the vehicle running engine. Such a land transport refrigeration apparatus 1 is called a sub-engine type. The sub-engine type refrigeration system 1 for land transportation is different from the direct connection type that uses the output of the vehicle traveling engine, and the operation of the compressor 3 that affects the cooling capacity is frequently performed according to the traveling state of the vehicle. It has the advantage that it is not affected by the vehicle running engine that causes fluctuations.

The outdoor heat exchanger 6 and the indoor heat exchangers 7 and 8 are configured by, for example, a rectangular parallel flow heat exchanger, but are not limited thereto.
On the discharge side of the compressor 3, a high-temperature gas port HG through which high-temperature and high-pressure refrigerant gas discharged from the compressor 3 passes is provided.
A low temperature gas port LG through which a low-pressure refrigerant gas returning to the compressor 3 passes is provided on the suction side of the compressor 3.

High-pressure gas pipes 9, 10, and 11 that connect one end of the pipes of the outdoor heat exchanger 6 and the indoor heat exchangers 7 and 8 and the high-pressure gas port HG are provided. The high-pressure gas pipes 9, 10, and 11 are arranged in parallel with each other.
The high-pressure gas pipes 9, 10, 11 are provided with high-pressure on-off valves 12, 13, 14 that are electromagnetic valves that open and close the pipes, respectively.

Low-pressure gas pipes 15 and 16 connecting the connection points X, Y and Z located on the downstream side in the refrigerant flow direction of the high-pressure on-off valves 12, 13 and 14 in the high-pressure gas pipes 9, 10 and 11 and the low-pressure gas port LG. , 17 are provided. The low-pressure gas pipes 15, 16, and 17 are arranged in parallel with each other.
The low-pressure gas pipes 15, 16, and 17 are provided with low-pressure on-off valves 18, 19, and 20 that are electromagnetic valves that open and close the pipes, respectively.

Outdoor air is supplied to the outdoor heat exchanger 6 by an outdoor fan 21.
Indoor air is supplied to the indoor heat exchangers 7 and 8 by indoor fans 22 and 23. The indoor fan 22 generates an airflow that circulates through the indoor heat exchanger 7 in the first cargo compartment 2A. The indoor fan 23 generates an airflow that circulates through the indoor exchanger 8 in the first cargo compartment 2B.

One ends of throttle pipes 25, 26, and 27 are connected to the other ends of the pipe lines of the outdoor heat exchanger 6 and the indoor heat exchangers 7 and 8, respectively. The throttle pipes 25, 26, 27 are arranged in parallel with each other.
The other ends of the throttle pipes 25, 26, 27 are connected to the high pressure liquid port HL and are connected to each other. In other words, the other ends of the throttle pipes 25, 26, 27 are joined at the high-pressure liquid port HL.

The throttle pipes 25, 26 and 27 are provided with throttle mechanisms 28, 29 and 30. The throttle mechanisms 28, 29, 30 are constituted by expansion valves 31, 32, 33 and throttle opening / closing valves 34, 35, 36.
The expansion valves 31, 32, and 33 have a function of depressurizing the refrigerant. The throttle opening / closing valves 34, 35, 36 are electromagnetic valves having a function of opening / closing the throttle pipes 25, 26, 27.
As the throttle mechanisms 28, 29, and 30, electronic expansion valves capable of adjusting the opening degree having the functions of the expansion valves 31, 32, and 33 and the throttle opening / closing valves 34, 35, and 36 may be used.

The throttle pipes 25, 26, 27 are provided with bypass pipes 37, 38, 39 that bypass the throttle mechanisms 28, 29, 30. The bypass pipes 37, 38 and 39 are provided with check valves 40, 41 and 42.
The check valves 40, 41, 42 prevent the refrigerant from flowing from the high pressure liquid port HL side to the outdoor heat exchanger 6 and the indoor heat exchanger 7, 8 side, and the outdoor heat exchanger 6 and the indoor heat exchanger 7. , 8 has a function of allowing flow from the high pressure liquid port HL side.

Regarding the refrigeration apparatus 1 for land transportation configured as described above, the operation during operation will be described with reference to FIGS.
FIGS. 2-11 is a block diagram which shows one operation state of the refrigeration apparatus for land transport concerning this embodiment, respectively.
In these drawings, among the high-pressure on-off valves 12, 13, and 14, the low-pressure on-off valves 18, 19, and 20 and the throttle on-off valves 34, 35, and 36, those that are painted black indicate an open state, and are outlined. The thing shows the closed state. Of the outdoor fan 21 and the indoor fans 22 and 23, those that are painted black indicate a state where the fan is operated and blown, and white ones indicate a state where it is stopped.
Among the high-pressure gas pipes 9, 10, 11, the low-pressure gas pipes 15, 16, 17, the throttle pipes 25, 26, 27, and the bypass pipes 37, 38, 39, those indicated by the thick lines indicate that the refrigerant is flowing. ing. The flow direction of the refrigerant is indicated by arrows.

FIG. 2 shows a case where the first cargo chamber 2A and the second cargo chamber 2B are being cooled.
In this case, the high-pressure on-off valve 12, the low-pressure on-off valves 19, 20 and the throttle on-off valves 35, 36 are opened, and the remaining on-off valves are closed. The outdoor fan 21 and the indoor fans 22 and 23 are all in operation.
When the compressor 3 is driven to rotate, a low-pressure refrigerant gas is sucked, compressed, and discharged as a high-temperature high-pressure superheated gas. This refrigerant gas is supplied from the high-pressure gas port HG to the outdoor heat exchanger 6 through the high-pressure gas pipe 9.
The refrigerant gas flowing into the outdoor heat exchanger 6 is heat-exchanged with the outside air ventilated by the outdoor fan 21 to be condensed and liquefied. That is, the outdoor heat exchanger 6 functions as a condenser (condenser).

Since the throttle opening / closing valve 34 is closed, the liquefied liquid refrigerant is sent to the high pressure liquid port HL through the bypass pipe 37 and flows into the throttle pipes 26 and 27. The liquid refrigerant flowing into the throttle pipes 26 and 27 is reduced in pressure by the throttle valves 32 and 33 and sent to the indoor heat exchangers 7 and 8.
The liquid refrigerant supplied to the indoor heat exchangers 7 and 8 is subjected to heat exchange with the indoor air circulated through the indoor heat exchangers 7 and 8 by the indoor fans 22 and 23 to be evaporated and gasified. At this time, since the heat of vaporization is taken from the room air, the room air is cooled. The inside of the first cargo chamber 2A and the second cargo chamber 2B is cooled to a predetermined temperature by this cooling air. That is, the indoor heat exchangers 7 and 8 function as heat absorbers (evaporators).
The gas refrigerant gasified by the indoor heat exchangers 7 and 8 is sucked into the suction side of the compressor 3 through the low-pressure gas pipes 16 and 17 and is compressed again. Thereafter, by repeating the same cycle, the cooling operation of the first cargo chamber 2A and the second cargo chamber 2B is performed.

FIG. 3 shows a case where the second loading chamber 2B is in a cooling operation and the first loading chamber 2A is stopped (including a stop due to thermo-off), that is, a cooling / stop mixed operation is performed.
In this case, the high-pressure on-off valve 12, the low-pressure on-off valves 19, 20 and the throttle on-off valve 36 are opened, and the remaining on-off valves are closed. The outdoor fan 21 and the indoor fan 23 are in operation.
Since the high-pressure on-off valve 12 is opened, the outdoor heat exchanger 6 is supplied with high-temperature and high-pressure refrigerant gas from the compressor 3. Since the supplied refrigerant gas is heat-exchanged with the outside air ventilated by the outdoor fan 21 to be condensed and liquefied, the outdoor heat exchanger 6 functions as a condenser (condenser).

The liquefied liquid refrigerant flows into the throttle pipe 27 via the bypass pipe 37 and the high pressure liquid port HL. The liquid refrigerant flowing into the throttle pipe 27 is decompressed by the throttle valve 33 and sent to the indoor heat exchanger 8.
The liquid refrigerant supplied to the indoor heat exchanger 8 is subjected to heat exchange with the indoor air circulated through the indoor heat exchanger 8 by the indoor fan 23 to be evaporated and gasified. At this time, since the heat of vaporization is taken from the room air, the room air is cooled. Since the inside of the second cargo chamber 2B is cooled to a predetermined temperature by this cooling air, the indoor heat exchanger 8 functions as a heat absorber (evaporator).
Since the throttle opening / closing valve 35 is closed, the refrigerant is not supplied to the indoor heat exchanger 7. Since the indoor fan 22 is not operated, the first cargo compartment 2A is in a state where the air conditioning operation is stopped.

Although the indoor fan 22 is stopped, in the case of stopping due to the thermo-off, it is desirable to operate the indoor fan 22 to circulate the indoor air in order to improve the temperature distribution in the first cargo compartment 2A. .
When the room temperature of the first cargo chamber 2A is lower than the low-pressure saturation temperature, the gas refrigerant flows into the indoor heat exchanger 7 through the low-pressure gas pipe 16, and the stagnation refrigerant increases. It is desirable to close.

FIG. 4 shows a case where the first cargo chamber 2A and the second cargo chamber 2B are heated.
In this case, the high-pressure on-off valves 13 and 14, the low-pressure on-off valve 18 and the throttle on-off valve 34 are opened, and the remaining on-off valves are closed. The outdoor fan 21 and the indoor fans 22 and 23 are all in operation.
Since the high-pressure on-off valves 13 and 14 are opened, the high-temperature and high-pressure refrigerant gas from the compressor 3 is supplied to the indoor heat exchangers 7 and 8 through the high-pressure gas pipes 10 and 11. The supplied refrigerant gas is heat-exchanged with the indoor air ventilated by the outdoor fans 22 and 23, cooled, and condensed and liquefied. At the same time, the room air is heated. The heated cargo air heats the first cargo compartment 2A and the second cargo compartment 2B to a predetermined temperature. That is, the indoor heat exchangers 7 and 8 function as condensers (condensers).

The liquefied liquid refrigerant is sent to the high-pressure liquid port HL through the bypass pipes 38 and 39 and flows into the throttle pipe 25 because the throttle opening / closing valves 35 and 36 are closed. The liquid refrigerant flowing into the throttle pipe 25 is depressurized by the throttle valve 31 and sent to the outdoor heat exchanger 6.
The liquid refrigerant supplied to the outdoor heat exchanger 6 is subjected to heat exchange with the outside air ventilated by the outdoor fan 21 to be evaporated and gasified. At this time, since the heat of vaporization is taken from the outdoor air, the outdoor air is cooled, so that the outdoor heat exchanger 6 functions as a heat absorber (evaporator).
The gas refrigerant gasified by the outdoor heat exchanger 6 is sucked into the suction side of the compressor 3 through the low-pressure gas pipe 15 and compressed again.

FIG. 5 shows a case where the second cargo compartment 2B is in a heating operation and the first cargo compartment 2A is stopped (including a stop by thermo-off), that is, a case where a heating / stop mixed operation is performed.
In this case, the high-pressure on-off valve 14, the low-pressure on-off valves 18, 19 and the throttle on-off valve 34 are opened, and the remaining on-off valves are closed. The outdoor fan 21 and the indoor fan 23 are in operation.
About the heating operation of the 2nd loading chamber 2B, the indoor heat exchanger 8 functions as a condenser (condenser), and the outdoor heat exchanger 6 functions as a heat absorber (evaporator) like the thing of FIG. . Since the operation is the same as that of FIG. 4, a duplicate description is omitted.
Since the high-pressure on-off valve 13 and the throttle on-off valve 35 are closed, the refrigerant is not supplied to the indoor heat exchanger 7. Since the indoor fan 22 is not operated, the first cargo compartment 2A is in a state where the air conditioning operation is stopped.

Although the indoor fan 22 is stopped, in the case of stopping due to the thermo-off, it is desirable to operate the indoor fan 22 to circulate the indoor air in order to improve the temperature distribution in the first cargo compartment 2A. .
When the room temperature of the first cargo chamber 2A is lower than the low-pressure saturation temperature, the gas refrigerant flows into the indoor heat exchanger 7 through the low-pressure gas pipe 16, and the stagnation refrigerant increases. It is desirable to close.

FIG. 6 shows a case where the second cargo compartment 2B is in a cooling operation and the first cargo compartment 2A is in a heating operation, that is, a cooling / heating mixed operation (cooling / heating mixed operation).
In this case, the high-pressure on-off valve 13, the low-pressure on-off valves 18, 20 and the throttle on-off valve 36 are opened, and the remaining on-off valves are closed. The indoor fans 22 and 23 are in operation.
Since the high-pressure on-off valve 12 and the throttle on-off valve 34 are closed, the refrigerant is not supplied to the outdoor heat exchanger 6. Since the outdoor fan 21 is not operated, the outdoor heat exchanger 6 is in a state where the air conditioning operation is stopped.
Note that the low-pressure on-off valve 18 is opened under operating conditions in which the refrigerant is recovered. For example, when the temperature of the outside air is lower than the low-pressure saturation temperature, the low-pressure on-off valve 18 passes through the low-pressure gas pipe 15. Since the gas refrigerant flows into the outdoor heat exchanger 6 and the stagnation refrigerant increases, it is desirable to close the low pressure on-off valve 18.

  Since the high-pressure on-off valve 13 is opened, the high-temperature and high-pressure refrigerant gas from the compressor 3 is supplied to the indoor heat exchanger 7 through the high-pressure gas pipe 10. The supplied refrigerant gas is heat-exchanged with the indoor air ventilated by the outdoor fan 22, cooled and condensed into liquid. At the same time, the room air is heated. The inside of the first cargo compartment 2A is heated to a predetermined temperature by this heated air. That is, the indoor heat exchanger 7 functions as a condenser (condenser).

Since the throttle opening / closing valve 35 is closed, the liquefied liquid refrigerant is sent to the high-pressure liquid port HL through the bypass pipe 38 and flows into the throttle pipe 27. The liquid refrigerant flowing into the throttle pipe 27 is depressurized by the throttle valve 36 and sent to the indoor heat exchanger 8.
The liquid refrigerant supplied to the indoor heat exchanger 8 is heat-exchanged with the indoor air circulated through the indoor heat exchanger 8 by the indoor fan 21 to be evaporated and gasified. At this time, since the heat of vaporization is taken from the room air, the room air is cooled. The inside of the second cargo chamber 2B is cooled to a predetermined temperature by this cooling air. That is, the indoor heat exchangers 7 and 8 function as heat absorbers (evaporators).
The gas refrigerant gasified by the indoor heat exchanger 8 is sucked into the suction side of the compressor 3 through the low-pressure gas pipe 17 and is compressed again.

  Thus, if the indoor heat exchanger 7 is caused to function as a condenser, while the indoor heat exchanger 8 is caused to function as a heat absorber, the cooling / heating mixing operation can be performed only with the indoor heat exchangers 7 and 8. it can. This is a heat exchange between the first luggage compartment 2A and the second cargo compartment 2B, and the efficiency of cooling or heating can be significantly improved.

FIG. 7 shows a case where the indoor heat exchangers 7 and 8 are simultaneously defrosted.
In this case, the high-pressure on-off valves 13 and 14, the low-pressure on-off valve 18 and the throttle on-off valve 34 are opened, and the remaining on-off valves are closed. Only the outdoor fan 21 is in operation.
Since the high-pressure on-off valves 13 and 14 are opened, the high-temperature and high-pressure refrigerant gas from the compressor 3 is supplied to the indoor heat exchangers 7 and 8 through the high-pressure gas pipes 10 and 11. The indoor heat exchangers 7 and 8 are defrosted according to the amount of heat of the supplied refrigerant gas. The refrigerant gas is partially or wholly liquefied depending on the amount of heat required for defrosting. That is, the indoor heat exchanger 7 functions as a condenser (condenser) although its capacity is reduced.
Since the throttle opening / closing valves 35 and 36 are closed, the refrigerant used for defrost is sent to the high pressure liquid port HL through the bypass pipes 38 and 39 and flows into the throttle pipe 25. The refrigerant flowing into the throttle pipe 25 is depressurized by the throttle valve 31 and sent to the outdoor heat exchanger 6. The liquid refrigerant supplied to the outdoor heat exchanger 6 is subjected to heat exchange with the outside air ventilated by the outdoor fan 21 to be evaporated and gasified. At this time, since the heat of vaporization is taken from the outdoor air, the outdoor air is cooled, so that the outdoor heat exchanger 6 functions as a heat absorber (evaporator).
The gas refrigerant gasified by the outdoor heat exchanger 6 is sucked into the suction side of the compressor 3 through the low-pressure gas pipe 15 and compressed again.

FIG. 8 shows a case where the first cargo compartment 2A is in the defrost operation and the second cargo compartment 2B is in the cooling operation, that is, the cooling / defrost mixed operation is being performed.
In this case, the high-pressure on-off valve 13, the low-pressure on-off valves 18, 20 and the throttle on-off valve 36 are opened, and the remaining on-off valves are closed. The indoor fan 23 is operating.
Since the high-pressure on-off valve 13 is opened, the high-temperature and high-pressure refrigerant gas from the compressor 3 is supplied to the indoor heat exchanger 7 through the high-pressure gas pipe 10. The indoor heat exchanger 7 is defrosted by the amount of heat of the supplied refrigerant gas. The refrigerant gas is partially or wholly liquefied depending on the amount of heat required for defrosting. That is, the indoor heat exchanger 7 functions as a condenser (condenser) although its capacity is reduced.

Since the throttle opening / closing valve 35 is closed, the refrigerant used for defrost is sent to the high-pressure liquid port HL through the bypass pipe 38 and flows into the throttle pipe 27. The refrigerant flowing into the throttle pipe 27 is depressurized by the throttle valve 33 and sent to the indoor heat exchanger 8. The liquid refrigerant supplied to the indoor heat exchanger 8 undergoes heat exchange with the outside air ventilated by the indoor fan 23 and is evaporated. At this time, since the heat of vaporization is taken from the outdoor air, the outdoor air is cooled, so that the indoor heat exchanger 8 functions as a heat absorber (evaporator).
The gas refrigerant gasified by the indoor heat exchanger 8 is sucked into the suction side of the compressor 3 through the low-pressure gas pipe 17 and is compressed again.

  When the condenser capacity in the indoor heat exchanger 7 is small, the pressure of the low-pressure gas returning from the indoor heat exchanger 8 to the compressor 3 increases, and the pressure of the refrigerant gas discharged from the compressor 3 increases excessively (high-pressure excessively increases). ). In this case, the outdoor heat exchanger 6 that is stopped by opening the high-pressure on-off valve 12 is used as a condenser. This reduces the high pressure overrise. When the high pressure decreases, the high pressure on-off valve 12 is closed and the function of the outdoor heat exchanger 6 is stopped.

FIG. 9 shows a case where the first cargo chamber 2A is in a defrost operation and the second cargo chamber 2B is in a heating operation, that is, a heating / defrost mixed operation is performed.
In this case, the high-pressure on-off valves 13 and 14, the low-pressure on-off valve 18 and the throttle on-off valve 34 are opened, and the remaining on-off valve is closed. The outdoor fan 21 and the indoor fan 23 are in operation.
Since the high-pressure on-off valve 13 is opened, the high-temperature and high-pressure refrigerant gas from the compressor 3 is supplied to the indoor heat exchanger 7 through the high-pressure gas pipe 10. The indoor heat exchanger 7 is defrosted by the amount of heat of the supplied refrigerant gas. The refrigerant gas is partially or wholly liquefied depending on the amount of heat required for defrosting. That is, the indoor heat exchanger 7 functions as a condenser (condenser) although its capacity is reduced.

  Further, since the high-pressure on-off valve 14 is opened, the indoor heat exchanger 8 is supplied with the high-temperature and high-pressure refrigerant gas from the compressor 3 through the high-pressure gas pipe 11. The supplied refrigerant gas is heat-exchanged with indoor air ventilated by the indoor fan 23, cooled and condensed into liquid. At the same time, the room air is heated. The inside of the second cargo compartment 2B is heated to a predetermined temperature by this heated air. That is, the indoor heat exchanger 8 functions as a condenser (condenser).

The liquefied liquid refrigerant is sent to the high-pressure liquid port HL through the bypass pipes 38 and 39 and flows into the throttle pipe 25 because the throttle opening / closing valves 35 and 36 are closed. The liquid refrigerant flowing into the throttle pipe 25 is depressurized by the throttle valve 31 and sent to the outdoor heat exchanger 6.
The liquid refrigerant supplied to the outdoor heat exchanger 6 is subjected to heat exchange with the outside air ventilated by the outdoor fan 21 to be evaporated and gasified. At this time, since the heat of vaporization is taken from the outdoor air, the outdoor air is cooled, so that the outdoor heat exchanger 6 functions as a heat absorber (evaporator).
The gas refrigerant gasified by the outdoor heat exchanger 6 is sucked into the suction side of the compressor 3 through the low-pressure gas pipe 15 and compressed again.

FIG. 10 shows a case where the first cargo compartment 2A is stopped and the second cargo compartment 2B is defrosted, that is, a stop / defrost mixed operation is performed.
In this case, the high-pressure on-off valve 14, the low-pressure on-off valves 18, 19 and the throttle on-off valve 34 are opened, and the remaining on-off valves are closed. The outdoor fan 21 is operating.
Since the high-pressure on-off valve 13 and the throttle on-off valve 35 are closed, the refrigerant is not supplied to the indoor heat exchanger 7. Since the indoor fan 22 is not operated, the first cargo compartment 2A is in a state where the air conditioning operation is stopped.
Since the high-pressure on / off valve 14 is opened, the high-temperature and high-pressure refrigerant gas from the compressor 3 is supplied to the indoor heat exchanger 8 through the high-pressure gas pipe 11. The indoor heat exchanger 8 is defrosted by the amount of heat of the supplied refrigerant gas. The refrigerant gas is partially or wholly liquefied depending on the amount of heat required for defrosting. That is, the indoor heat exchanger 8 functions as a condenser (condenser) although its capacity is reduced.

Since the throttle opening / closing valve 36 is closed, the liquefied liquid refrigerant is sent to the high-pressure liquid port HL through the bypass pipe 39 and flows into the throttle pipe 25. The liquid refrigerant flowing into the throttle pipe 25 is depressurized by the throttle valve 31 and sent to the outdoor heat exchanger 6.
The liquid refrigerant supplied to the outdoor heat exchanger 6 is subjected to heat exchange with the outside air ventilated by the outdoor fan 21 to be evaporated and gasified. At this time, since the heat of vaporization is taken from the outdoor air, the outdoor air is cooled, so that the outdoor heat exchanger 6 functions as a heat absorber (evaporator).
The gas refrigerant gasified by the outdoor heat exchanger 6 is sucked into the suction side of the compressor 3 through the low-pressure gas pipe 15 and compressed again.
The outdoor fan 21 stops operation when the pressure of the refrigerant gas at the outlet of the compressor 3 is high.

FIG. 11 shows a case where the outdoor heat exchanger 6 is defrosted.
In this case, the high-pressure on-off valve 12, the low-pressure on-off valves 19, 20 and the throttle on-off valves 35, 36 are opened, and the remaining on-off valves are closed. The outdoor fan 21 and the indoor fans 22 and 23 are not in operation.
Since the high-pressure on-off valve 12 is opened, the high-temperature and high-pressure refrigerant gas from the compressor 3 is supplied to the outdoor heat exchanger 6 through the high-pressure gas pipe 9. The indoor heat exchanger 6 is defrosted by the amount of heat of the supplied refrigerant gas. The refrigerant gas is partially or wholly liquefied depending on the amount of heat required for defrosting. That is, the outdoor heat exchanger 6 functions as a condenser (condenser) although the capacity is reduced.

Since the throttle opening / closing valve 34 is closed, the refrigerant used for defrost is sent to the high-pressure liquid port HL through the bypass pipe 37 and flows into the throttle pipes 26 and 27. The refrigerant flowing into the throttle pipes 26 and 27 is decompressed by the throttle valves 32 and 33 and sent to the indoor heat exchangers 7 and 8. The liquid refrigerant supplied to the indoor heat exchangers 7 and 8 is subjected to heat exchange with the surrounding indoor air to be evaporated. At this time, since the heat of vaporization is taken away from the indoor air, the outdoor air is cooled, so that the indoor heat exchangers 7 and 8 function as heat absorbers (evaporators) with a small capacity.
The gas refrigerant gasified by the indoor heat exchangers 7 and 8 is sucked into the suction side of the compressor 3 through the low-pressure gas pipes 16 and 17 and is compressed again.

Thus, since the outdoor heat exchanger 6 and the indoor heat exchangers 7 and 8 can be used independently as a condenser or a heat absorber, various operations are performed as illustrated in FIGS. be able to.
If the indoor heat exchangers 7 and 8 are used as condensers, the room air in the first cargo chamber 2A and the second cargo chamber 2B is heated, so that a heating operation can be performed. Since this heating operation is heat pump heating, it is efficient and can provide a large heating capacity. Defrost time can be shortened.

When changing the operation method, the high-pressure on-off valves 12, 13, 14, the low-pressure on-off valves 18, 19, 20 and the throttle on-off valves 34, 35, 36 are switched on and off. Therefore, stable and reliable switching can be performed under any conditions.
Thereby, it can apply also to the direct connection type refrigeration apparatus for land transport in which the state of a compressor may change a lot.

  Further, since the heating operation can be performed only with the refrigeration apparatus 1 for land transportation, it is not necessary to use the heat of the engine cooling water of the vehicle engine as conventionally used. Is reduced. Moreover, since engine cooling water can be fully utilized for cabin heating, the comfort of cabin heating can be improved.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably.

DESCRIPTION OF SYMBOLS 1 Refrigeration equipment for land transport 2A 1st loading room 2B 2nd loading room 3 Compressor 4 Power source 6 Outdoor heat exchangers 7, 8 Indoor heat exchangers 9, 10, 11 High pressure gas piping 12, 13, 14 High pressure on-off valve 15, 16, 17 Low pressure gas pipe 18, 19, 20 Low pressure on-off valve 25, 26, 27 Throttle pipe 28, 29, 30 Throttle mechanism 37, 38, 39 Bypass pipe 40, 41, 42 Check valve

Claims (1)

A compressor,
With a plurality of heat exchangers,
The plurality of heat exchangers are:
A plurality of indoor heat exchangers installed respectively in a plurality of refrigeration compartments separated by cargo compartments;
An outdoor heat exchanger installed outside the cargo compartment,
A refrigeration system for land transportation capable of creating a plurality of different transport temperatures in the plurality of refrigeration compartments,
A plurality of high-pressure gas pipes respectively connecting a discharge side of the compressor and one ends of pipes of the plurality of heat exchangers;
A plurality of high-pressure on-off valves that respectively open and close the plurality of high-pressure gas pipes;
A plurality of low-pressure gas pipes respectively connecting one end of pipes of the plurality of heat exchangers and a suction side of the compressor;
A plurality of low-pressure on-off valves that respectively open and close the plurality of low-pressure gas pipes;
A plurality of throttle pipes respectively connecting the other end of the pipes of the plurality of heat exchangers and the high-pressure liquid port;
Opening and closing the plurality of throttle pipes, respectively, and a plurality of throttle mechanisms having a pressure reducing function;
A plurality of bypass pipes respectively connecting the other ends of the pipes of the plurality of heat exchangers and the high-pressure liquid port so as to bypass the plurality of throttle mechanisms;
A plurality of check valves that respectively prevent refrigerant from flowing from the high-pressure liquid port into the plurality of heat exchangers via the plurality of bypass pipes;
Is provided ,
The plurality of high-pressure on-off valves, the plurality of throttle mechanisms, and the plurality of low-pressure on-off valves are configured such that an arbitrary heat exchanger of the plurality of heat exchangers is supplied with the refrigerant from a discharge side of the compressor. Is supplied to the high-pressure liquid port, or the optional heat exchanger is supplied with the refrigerant from the high-pressure liquid port and supplies the refrigerant to the suction side of the compressor, or the optional the so coolant is not supplied to the heat exchanger, opening and closing by a refrigeration unit for land transportation according to claim Rukoto.

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