Refrigerating unit of semitrailer

Abstract

The utility model discloses a refrigerating unit of a semitrailer, and belongs to the technical field of refrigerating units of refrigerated trucks. A heat preservation shell is arranged in the machine frame, an evaporation cavity is formed in one side of the heat preservation shell, an evaporator is arranged in the evaporation cavity, condensation air ducts are arranged at one end or two ends of the other side of the heat preservation shell, a condenser and a refrigerating system are arranged outside the condensation air ducts, and the condenser and the evaporator are both communicated with the corresponding refrigerating system. And a compressor in the refrigerating system is connected with the power mechanism. The two independent refrigerating systems are arranged in the refrigerating unit and provided with the corresponding compressors and the corresponding condensers, one refrigerating system can be selectively started according to needs in the using process, the two refrigerating systems can also be started at the same time, and when one refrigerating system breaks down, the compressor and the condenser can be started at the same time. And the other set of refrigerating system can maintain the cooling temperature of the goods in the carriage, so that the damage of the goods is reduced, and more conditions are created for first-aid repair.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of refrigeration unit of refrigerated truck, concretely speaking, especially relate to a semi-trailer refrigeration unit. BACKGROUND

[0002] The semi-trailer and refrigerated truck usually install refrigeration unit at the front end of the closed carriage to realize accurate refrigeration of the carriage. For example, the semi-trailer, the refrigeration unit is installed at the front end of the carriage, according to the national standard, the distance between the truck head and the carriage is a fixed value, so that the thickness of the refrigeration unit cannot exceed 610mm under the premise of ensuring the effective steering distance of the truck head.

[0003] The Chinese patent with publication number "CN210454592U" discloses a new refrigeration unit for refrigerated semi-trailer, which is arranged on the condenser assembly, and the hot air is discharged upward, which can facilitate the rapid discharge of hot air in both driving and parking states, improve the refrigeration capacity and speed up the cooling speed, and when the unit fails, the evaporative fan can be quickly repaired and replaced without removing the goods in the carriage.

[0004] However, the above refrigeration unit has the following problems when installed and used:

[0005] 1. The refrigeration unit is of rectangular structure, and when the semi-trailer truck head is steering, the two straight angles of the rectangular structure are easy to interfere with the truck head, which is very inconvenient to use.

[0006] 2. The compressor, condenser and corresponding refrigeration system in the refrigeration unit are only one set, and the condenser is arranged in the middle of the refrigeration unit, which leads to small heat dissipation area of the condenser and poor refrigeration effect, and when the refrigeration system fails, the temperature in the carriage cannot be maintained stable.

[0007] 3. The refrigeration system usually uses diesel generator to provide power, which is noisy and pollutes the air. With the introduction of environmental protection standards such as tail gas emission and noise, the range of normal use of refrigerated semi-trailer is gradually reduced. UTILITY MODEL CONTENTS

[0008] The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art, provide a semi-trailer refrigeration unit, two independent refrigeration systems are arranged in the refrigeration unit, and the two refrigeration systems are each equipped with a corresponding compressor and condenser, and one of the refrigeration systems can be selectively opened according to the need, or both refrigeration systems can be opened at the same time, when one refrigeration system fails, the other refrigeration system can also maintain the cooling temperature of the goods in the carriage, reduce the loss of goods, and create more conditions for repair.

[0009] The semi-trailer refrigeration unit comprises a rack, a heat preservation shell arranged in the rack, an evaporation cavity arranged on one side of the heat preservation shell, an evaporator arranged in the evaporation cavity, a condensing air duct arranged at one end or both ends of the other side of the heat preservation shell, a condenser and a refrigeration system arranged outside the condensing air duct, and a compressor in the refrigeration system connected with a power mechanism.

[0010] Preferably, the power mechanism is a power generator, and the compressor is a scroll compressor; the power generator is arranged at a position close to the middle of the bottom of the rack; the compressor, the refrigeration system and the condenser are all arranged in two groups; the two groups of the compressor, the refrigeration system and the condenser are arranged on both sides of the power generator; any one or both of the condensers is internally provided with a heat dissipation water tank for cooling the mechanical structure of the power generator; the heat preservation shell is arranged above the rack; the condenser and the heat dissipation water tank are both in an arc shape; and the condenser and the heat dissipation water tank enclose the condensing air duct.

[0011] Preferably, the volume of the evaporation cavity gradually decreases from bottom to top; the bottom of the evaporation cavity is arranged in an upward inclination; and the volume of the condensing air duct gradually increases from bottom to top.

[0012] Preferably, the evaporator is fixedly arranged at the bottom of the evaporation cavity; the upper end of the evaporator is arranged in an inclination away from the evaporation cavity; an evaporation air duct is formed between the evaporator and the inner wall of the evaporation cavity; the volume of the evaporation air duct gradually increases from bottom to top; an evaporation fan is arranged at the upper portion of the evaporation air duct; and a maintenance opening corresponding to the evaporation fan is arranged on the heat preservation shell.

[0013] Preferably, the evaporator is internally provided with multiple groups of heat exchange coils; each group of heat exchange coils comprises coil one and coil two arranged in an interlacing manner; the multiple groups of coil one are all in communication with a corresponding group of refrigeration systems; and the multiple groups of coil two are all in communication with another group of refrigeration systems.

[0014] Preferably, the evaporator is internally provided with multiple groups of straight pipe sections arranged at equal intervals; each group of straight pipe sections comprises multiple straight pipe sections arranged in parallel and at equal intervals; the straight pipe sections in adjacent two groups of straight pipe sections are arranged in an interlacing manner; coil one is formed by multiple straight pipe sections and bend pipe section one connected in sequence; and coil two is formed by multiple straight pipe sections and bend pipe section two connected in sequence.

[0015] Preferably, the two ends of coil one are respectively provided with refrigerant inlet one and refrigerant outlet one; the two ends of coil two are respectively provided with refrigerant inlet two and refrigerant outlet two; multiple groups of refrigerant inlets one are in common communication with a total liquid inlet pipe one; multiple groups of refrigerant outlets one are in common communication with a total liquid outlet pipe one; the total liquid inlet pipe one and the total liquid outlet pipe one are in communication with a corresponding group of refrigeration systems; multiple groups of refrigerant inlets two are in common communication with a total liquid inlet pipe two; multiple groups of refrigerant outlets two are in common communication with a total liquid outlet pipe two; and the total liquid inlet pipe two and the total liquid outlet pipe two are in communication with another group of refrigeration systems.

[0016] Preferably, the refrigeration system comprises a compressor, a condenser, an evaporator, an expansion valve two, an electromagnetic valve one and an electromagnetic valve two, the high-pressure outlet of the compressor is communicated with the condenser through the electromagnetic valve one, the condenser is connected with the expansion valve two, the expansion valve two is connected with the evaporator, the high-pressure outlet of the compressor is connected with the evaporator through the electromagnetic valve two, and the outlet of the evaporator is communicated with the low-pressure outlet of the compressor.

[0017] Preferably, an auxiliary heat exchange mechanism is arranged between the condenser and the expansion valve two, the auxiliary heat exchange mechanism comprises a liquid storage tank, a drying filter, a plate heat exchanger and an expansion valve one, the plate heat exchanger is internally provided with a first heat exchange channel and a second heat exchange channel, the outlet of the condenser is communicated with the liquid storage tank through a one-way valve two, the liquid storage tank is communicated with the drying filter, the outlet of the drying filter is communicated with the second heat exchange channel through a pipeline one, the second heat exchange channel is connected with the expansion valve two through an electromagnetic valve four, the outlet of the drying filter is connected with the expansion valve one through a pipeline two, the pipeline two is provided with an electromagnetic valve three, the expansion valve one is communicated with the first heat exchange channel, and the outlet of the first heat exchange channel is communicated with the medium-temperature steam return port of the compressor.

[0018] Preferably, the electromagnetic valve two is communicated with the liquid storage tank through a one-way valve three.

[0019] Compared with the prior art, the refrigeration system has the advantages that:

[0020] 1、The two independent refrigeration systems are integrated in the limited space, the two refrigeration systems can be operated simultaneously or at different times, the flexibility is high, when one refrigeration system fails, the other refrigeration system can also maintain the cooling temperature of the goods in the carriage, reduces the goods loss, and creates more conditions for repair.

[0021] 2、The heat preservation shell is additionally arranged, the evaporation cavity is formed in one side of the heat preservation shell, and the condensing air ducts are arranged at two ends of the other side, so that the evaporator and the condenser are reasonably arranged, the heat exchange effect of the evaporator and the condenser is ensured, the maintenance opening is arranged on the heat preservation shell, and the operator can maintain the evaporating fan at the rear of the vehicle head, that is, the outside of the carriage, the operator needs to enter the carriage and unload the goods in the carriage for maintenance in the prior art, and the maintenance efficiency of the evaporating fan is greatly improved.

[0022] 3、The two independent evaporation mechanisms are arranged in the evaporator and are staggered and uniformly distributed in the evaporator, the temperature in the evaporator is uniform when only one evaporation mechanism works, the heat exchange efficiency of the whole evaporator is higher, and the evaporation effect is improved, the two evaporation mechanisms are integrated in the evaporator, the two refrigeration systems can independently work, and the space is greatly saved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The external structure of the present utility model is shown in the figure Figure 1 ;

[0024] Figure 2 The external structure of the present utility model is shown in the figure Figure 2 ;

[0025] Figure 3 The internal structure of the present utility model is shown in the figure Figure 1 ;

[0026] Figure 4 The internal structure of the present utility model is shown in the figure Figure 2 ;

[0027] Figure 5 The top view structure of the present utility model is shown in the figure

[0028] Figure 6 The front structure of the heat preservation shell is shown in the figure

[0029] Figure 7 The back structure of the heat preservation shell is shown in the figure

[0030] Figure 8 The side structure of the heat preservation shell is shown in the figure

[0031] Figure 9 The top view structure of the heat preservation shell is shown in the figure

[0032] Figure 10 The external structure of the evaporator is shown in the figure

[0033] Figure 11 The internal structure of the evaporator is shown in the figure

[0034] Figure 12 The left view of the evaporator is shown in the figure

[0035] Figure 13 The left view of the evaporator is shown in the figure Figure 12 The left view of the evaporator is shown in the figure

[0036] Figure 14 The cooperation of the coil one and the coil two is shown in the figure Figure 1 ;

[0037] Figure 15 The right view of the evaporator is shown in the figure

[0038] Figure 16 The cooperation of the coil one and the coil two is shown in the figure Figure 2 ;

[0039] Figure 17 The split of the coil one and the coil two is shown in the figure

[0040] Figure 18The utility model discloses a refrigeration system's principle diagram.

[0041] In the drawing, 1, condenser, 2, condensing fan, 3, access hole, 4, power generator, 5, evaporator, 501, coil one, 5011, refrigerant import one, 5012, refrigerant export one, 5013, straight pipe section, 5014, bend pipe section one, 502, coil two, 5021, refrigerant import two, 5022, refrigerant export two, 5023, bend pipe section two,

[0042] 6, evaporating fan, 7, compressor, 701, high-pressure steam outlet, 702, medium-temperature steam return port, 703, low-pressure steam outlet, 8, heat preservation shell, 801, evaporating cavity, 802, inner side plate, 803, condensing air duct, 9, heat dissipation water tank, 10, electromagnetic valve one, 11, electromagnetic valve two, 12, one-way valve one, 13, one-way valve two, 14, one-way valve three, 15, liquid storage tank, 16, drying filter, 17, electromagnetic valve three, 18, expansion valve one, 19, plate heat exchanger, 20, electromagnetic valve four, 21, expansion valve two, 22, liquid distribution head, 23, rack. DETAILED DESCRIPTION

[0043] The utility model will be further explained in connection with the drawings as follows:

[0044] The orientation terms involved in the paragraphs of detailed description are only for the convenience of the person skilled in the art to understand the technical solutions recorded in the application according to the visual orientation shown in the drawings. Except for explicit provisions and limitations, the terms "set", "install", "connect" and the like should be understood broadly, and the person skilled in the art can understand the specific meaning of the above terms in the utility model according to the specific circumstances.

[0045] Example one:

[0046] As Figures 1 to 18 shown, a semi-trailer refrigeration unit, including rack 23, rack 23 plays the main support role, the rack 23 is equipped with heat preservation shell 8, and the heat preservation shell 8 is provided with evaporating cavity 801 on one side, and the evaporating cavity 801 is provided with evaporator 5, and the heat preservation shell 8 is provided with condensing air duct on the other side, and the condensing air duct is provided with condenser 1 and refrigeration system outside, and the condenser 1 and evaporator 5 are communicated with the refrigeration system, and the compressor 7 in the refrigeration system is connected with the power mechanism.

[0047] Example two:

[0048] The semi-trailer refrigeration unit, two ends of the other side of the heat preservation shell 8 are respectively provided with condensing air ducts, each condensing air duct is externally provided with a group of condensers 1 and refrigeration systems, the evaporator 5 is internally provided with multiple groups of heat exchange coils, each group of heat exchange coils comprises staggered coil one 501 and coil two 502, the multiple groups of coil one 501 are in communication with a group of refrigeration systems close to the coil one 501, and the multiple groups of coil two 502 are in communication with another group of refrigeration systems. In the embodiment, two sets of evaporators are integrated into one evaporator, which not only ensures that the two groups of refrigeration systems can independently operate, but also greatly saves space.

[0049] Specifically, the heat preservation shell 8 comprises an inner shell and an outer shell, and a heat preservation layer is filled between the inner shell and the outer shell, and the heat preservation shell 8 is used for reasonably arranging the evaporator 5 and the condenser 1, and ensuring the heat exchange effect of the evaporator 5 and the condenser 1. In the embodiment, the power mechanism is a power generator 4, and the compressor 7 is a scroll compressor. Compared with the engine driving the piston compressor through the mechanical linkage in the prior art, the problem that leakage of freon and other refrigerants easily occurs at the connection of the compressor is avoided. The mechanical linkage structure is an angle conversion through a transmission shaft, an angle converter, a belt, a centrifugal clutch, an electromagnetic clutch, a motor and other mechanical devices. During operation, there is wear and tear, and maintenance is relatively complex. Meanwhile, a large amount of energy is lost during operation. In the embodiment, the scroll compressor is driven by electric energy and is fully enclosed, so that leakage of refrigerants is avoided, and overall maintenance is more convenient.

[0050] As shown in Figure 3 , the power generator 4 is arranged at the bottom of the rack 23 close to the middle, the refrigeration system and the condenser 1 are both two groups, and the two groups of refrigeration systems and the condenser 1 are arranged on both sides of the power generator 4, as shown in Figure 5 , any one or both of the condensers 1 is internally provided with a heat dissipation water tank 9 for cooling the mechanical structure of the power generator 4; the heat preservation shell 8 is arranged above the rack 23, the condenser 1 and the heat dissipation water tank 9 are both in an arc structure, and the condenser 1 and the heat dissipation water tank 9 enclose the condensing air duct, and the condensing fan 2 is arranged on the upper part of the condensing air duct. The condenser 1 and the heat dissipation water tank 9 are both in an arc structure, which does not hinder the steering of the semi-trailer truck during transportation, and the arc structure makes full use of the internal space of the refrigeration unit, increases the heat dissipation area of the condenser 1, and improves the heat dissipation effect.

[0051] As shown in Figures 6 to 9As shown, the evaporation chamber 801 gradually decreases in volume from bottom to top. Specifically, inner side plates 802 are provided on both sides of the evaporation chamber 801, with the inner side plates 802 inclined towards the side away from the evaporation chamber 801. The bottom inner side of the evaporation chamber 801 is inclined upwards. The outer shell of the insulation shell 8, on the side away from the evaporation chamber 801, has a similar shape to the evaporation chamber 801. The condensing air duct 803 gradually increases in volume from bottom to top. During manufacturing, the evaporation chamber 801 and the condensing air duct 803 adopt a streamlined design with a smooth transition, which can avoid turbulence in the airflow system and thus improve the air circulation effect. The evaporator 5 is fixedly installed at the bottom of the evaporation chamber 801. Because the bottom of the evaporation chamber 801 is inclined upwards, the upper end of the evaporator 5 is inclined towards the side away from the evaporation chamber 801 after installation. At this time, an evaporation air duct is formed between the evaporator 5 and the inner wall of the evaporation chamber 801, and the volume of the evaporation air duct gradually increases from bottom to top. An evaporator fan 6 is installed at the upper part of the evaporator duct. The evaporator fan 6 is sealed and fixed to the inner wall of the insulation shell 8 through a sealing plate. The sealing plate blocks the upper part of the evaporator duct. The insulation shell 8 has an inspection port 3 corresponding to the evaporator fan 6. Through the inspection port 3, the operator can carry out maintenance on the evaporator fan 6 from behind the front of the car, that is, outside the car body. This avoids the predicament of the current technology where the operator has to enter the car body and unload the cargo before maintenance, and greatly improves the maintenance efficiency of the evaporator fan 6.

[0052] The evaporator duct and condenser duct 803 have gradually increasing volumes from bottom to top, and their airflow principles are the same. Taking the condenser duct 803 as an example, when the condenser fan 2 is started, the condenser fan 2 creates a local negative pressure above the condenser duct 803, and the volume of the condenser duct 803 gradually increases from bottom to top, so that the condenser 1 can be evenly aired from bottom to top, making the heat exchange of the condenser 1 more uniform.

[0053] like Figures 10 to 17 As shown, the evaporator 5 has a rectangular structure. Inside the evaporator 5, there are multiple rows of straight pipe sections arranged at equal intervals. The straight pipe sections are supported and fixed by the shell of the evaporator 5. Each row of straight pipe sections includes multiple parallel and equally spaced straight pipe sections 5013. The straight pipe sections 5013 in adjacent rows of straight pipe sections are staggered. Coil 1 501 is formed by connecting multiple straight pipe sections 5013 and bend section 1 5014 in series. Coil 2 502 is formed by connecting multiple straight pipe sections 5013 and bend section 2 5023 in series. In this design, coil 501 and coil 502 in each heat exchange coil group are arranged independently and alternately. Multiple coils 501 together form one evaporation mechanism, and multiple coils 502 together form another evaporation mechanism. This structure integrates two evaporation mechanisms into one evaporator 5, resulting in a more compact structure. At the same time, the two types of coils are more evenly distributed within the evaporator 5. Even when only one evaporation mechanism is working, the internal temperature of the evaporator 5 is still very uniform, making the heat exchange efficiency of the entire evaporator 5 higher and thus improving the evaporation effect.

[0054] As Figure 14 , Figure 16 and Figure 17 shown, the two ends of the coil one 501 are provided with a refrigerant inlet one 5011 and a refrigerant outlet one 5012, respectively, the two ends of the coil two 502 are provided with a refrigerant inlet two 5021 and a refrigerant outlet two 5022, respectively, a plurality of refrigerant inlets one 5011 are commonly connected with a total liquid inlet pipe one, a plurality of refrigerant outlets one 5012 are commonly connected with a total liquid outlet pipe one, the total liquid inlet pipe one and the total liquid outlet pipe one are connected with a corresponding group of refrigeration systems, a plurality of refrigerant inlets two 5021 are commonly connected with a total liquid inlet pipe two, a plurality of refrigerant outlets two 5022 are commonly connected with a total liquid outlet pipe two, and the total liquid inlet pipe two and the total liquid outlet pipe two are connected with another group of refrigeration systems. In this way, the two groups of refrigeration systems are independent of each other. The rest is the same as example one.

[0055] Example three:

[0056] A semi-trailer refrigeration unit, the refrigeration system includes a compressor 7, a condenser 1, an evaporator 5, an expansion valve two 21, an electromagnetic valve one 10 and an electromagnetic valve two 11, the electromagnetic valve one 10 is a normally open electromagnetic valve, the electromagnetic valve two 11 is a normally closed electromagnetic valve, the high-pressure outlet 701 of the compressor 7 is connected with the condenser 1 through the electromagnetic valve one 10, the condenser 1 is connected with the expansion valve two 21, the expansion valve two 21 is connected with the evaporator 5, the high-pressure outlet 701 of the compressor 7 is connected with the evaporator 5 through the electromagnetic valve two 11, and the outlet of the evaporator 5 is connected with the low-pressure outlet 703 of the compressor 7. The rest is the same as example two.

[0057] In this embodiment, the two groups of refrigeration systems can run simultaneously, or only one of them can run. In this way, when one group of refrigeration systems fails, the other group of refrigeration systems can ensure the refrigeration temperature in the carriage, greatly improving the stability of the refrigeration system.

[0058] When refrigeration is normal, the compressor 7 is filled with refrigerant, the compressor 7 is started by the power generator 4 or an external power source, the compressor 7 compresses the refrigerant into high-temperature and high-pressure refrigerant gas, the electromagnetic valve one 10 is a normally open electromagnetic valve, the refrigerant gas passes through the high-pressure outlet 701 and enters the condenser 1 to exchange heat with the surrounding air, at this time, the refrigerant gas becomes medium-temperature and high-pressure liquid refrigerant after cooling, the liquid refrigerant becomes low-temperature and low-pressure liquid after throttling and cooling by the expansion valve two 21, and enters the evaporator 5, and further exchanges heat with the surrounding air in the evaporator 5 to absorb heat from the air, at this time, the temperature of the refrigerant is raised to achieve the refrigeration effect, and finally the refrigerant returns to the compressor 7 through the low-pressure outlet 703 to circulate and work.

[0059] When defrosting, the electromagnetic valve one 10 is closed, the electromagnetic valve two 11 is opened, and the compressor 7 is started. The high-temperature and high-pressure refrigerant gas directly enters the evaporator 5 through the electromagnetic valve two 11 to be heated and defrosted, which greatly improves the defrosting efficiency. With the continuous heat exchange between the refrigerant and the evaporator 5, the superheat degree of the refrigerant in the low-pressure return pipe between the low-pressure outlet 703 of the compressor 7 and the outlet of the evaporator 5 changes continuously. When the temperature of the evaporator 5 is relatively high, the pressure in the low-pressure return pipe gradually increases, which may cause the compressor 7 to run in overload. At this time, to avoid the above situation, the electromagnetic valve one 10 is opened, so that part of the high-temperature and high-pressure refrigerant gas enters the condenser 1 to be cooled and temporarily stored, thereby reducing the amount of refrigerant entering the low-pressure system, and further reducing the pressure of the low-pressure system. The high and low pressures in the compressor 7 system are controllable, which ensures that the compressor 7 always runs in an ideal state range, prolonging the service life of the refrigeration system.

[0060] Example four:

[0061] As shown in Figure 18 A semi-trailer refrigeration unit, a condenser 1 and an expansion valve two 21 are provided with an auxiliary heat exchange mechanism. The auxiliary heat exchange mechanism includes a liquid storage tank 15, a drying filter 16, a plate heat exchanger 19, and an expansion valve one 18. The plate heat exchanger 19 is provided with a first heat exchange passage and a second heat exchange passage. The outlet of the condenser 1 is communicated with the liquid storage tank 15 through a one-way valve two 13. The liquid storage tank 15 is communicated with the drying filter 16. The outlet of the drying filter 16 is communicated with the second heat exchange passage through a pipeline one. The second heat exchange passage is connected with the expansion valve two 21 through an electromagnetic valve four 20. The outlet of the drying filter 16 is connected with the expansion valve one 18 through a pipeline two. The pipeline two is provided with an electromagnetic valve three 17. The expansion valve one 18 is communicated with the first heat exchange passage. The outlet of the first heat exchange passage is communicated with the medium-temperature return port 702 of the compressor 7. The high-pressure outlet port 701 is connected with the electromagnetic valve one 10 and the electromagnetic valve two 11 through a main pipeline. The main pipeline is provided with a one-way valve one 12. The electromagnetic valve two 11 is communicated with the liquid storage tank 15 through a one-way valve three 14. The others are the same as example three.

[0062] In the normal refrigeration, the compressor 7 is filled with refrigerant, the compressor 7 is started by the power generator 4 or external power source, the compressor 7 compresses the refrigerant into high-temperature and high-pressure refrigerant gas, the high-temperature and high-pressure refrigerant gas enters the condenser 1 through the total pipeline and the electromagnetic valve 10 to exchange heat with the surrounding air, at this time, the refrigerant gas is cooled into medium-temperature and high-pressure liquid refrigerant, the liquid refrigerant sequentially enters the liquid storage tank 15 and the drying filter 16 to be stored and dried and filtered, part of the filtered refrigerant enters the expansion valve 1 through the electromagnetic valve 3, is throttled and cooled by the expansion valve 1 and becomes low-temperature and low-pressure liquid refrigerant, the refrigerant enters the first heat exchange channel, the first heat exchange channel exchanges heat with the second heat exchange channel in the plate heat exchanger 19, the refrigerant in the first heat exchange channel absorbs heat and becomes medium-temperature, and finally returns to the compressor 7 through the medium-temperature steam outlet 702, the channel exchanges heat with the refrigeration pipeline and pre-cools the compressor 7, so that the compressor 7 is protected and overheating of the compressor 7 is avoided.

[0063] Another part of the filtered refrigerant enters the second heat exchange channel in the plate heat exchanger 19 to exchange heat with the first heat exchange channel and is supercooled, passes through the electromagnetic valve 4 and enters the expansion valve 2, the expansion valve 2 throttles and cools the refrigerant, at this time, the refrigerant becomes low-temperature and low-pressure liquid, is uniformly distributed through the liquid distribution head 22 and flows into the evaporator 5 to exchange heat with air, absorbs heat in the air, completes the refrigeration function and finally returns to the compressor 7 to continue compression and circulation. The channel constitutes the refrigeration pipeline, exchanges heat with the plate heat exchanger 19, improves the refrigeration efficiency and refrigeration effect.

[0064] During defrosting, the electromagnetic valve 1, the electromagnetic valve 3 and the electromagnetic valve 4 are closed, the electromagnetic valve 2 is opened, the high-temperature and high-pressure refrigerant gas enters the evaporator 5 to be heated and defrosted through the liquid distribution head 22 and the other parts are the same as in the third embodiment.

[0065] During the heating and defrosting process, the high-temperature and high-pressure refrigerant gas enters the liquid storage tank 15 and the drying filter 16 through the electromagnetic valve 2 and the one-way valve 3 to be stored and dried and filtered, the system is supplemented with liquid by opening the electromagnetic valve 4.

[0066] In the defrosting and normal refrigeration, when the electromagnetic valve 4 in the refrigeration pipeline is in the closed state, the pressure balance at both ends of the electromagnetic valve 4 can be realized, the normal and stable operation of the electromagnetic valve 4 is ensured and the problem that the electromagnetic valve is broken due to unbalanced pressure in the system and the system is broken is avoided in the prior art.

[0067] Finally, although the present specification is described in terms of embodiments, not every embodiment exhibits every characteristic or implements every combination of features described in the present specification. The present specification has been described in a manner that is thorough and complete to one skilled in the art and the specification is intended to be construed as an exemplification of one or more embodiments rather than as an exhaustive list of embodiments.

Claims

1. A semi-trailer refrigeration unit comprising a chassis (23) characterised in that: A rack (23) is internally provided with a heat preservation shell (8), the heat preservation shell (8) is provided with an evaporation cavity (801) on one side, the evaporation cavity (801) is internally provided with an evaporator (5), one end or both ends of the other side of the heat preservation shell (8) are provided with a condensing air duct, the condensing air duct is externally provided with a condenser (1) and a refrigeration system, the condenser (1) and the evaporator (5) are communicated with the corresponding refrigeration system, and a compressor (7) in the refrigeration system is connected with a power mechanism.

2. The semi-trailer chiller unit of claim 1, wherein: The power mechanism is a power generator (4), the compressor (7) is a scroll compressor, the power generator (4) is arranged at a position close to the middle of the bottom of the rack (23), the compressor (7), the refrigeration system and the condenser (1) are all two groups, the two groups of compressor (7), the refrigeration system and the condenser (1) are arranged on both sides of the power generator (4), and any one or both of the condensers (1) are internally provided with a heat dissipation water tank (9) for cooling the mechanical structure of the power generator (4); the heat preservation shell (8) is installed above the rack (23), the condenser (1) and the heat dissipation water tank (9) are both in an arc structure, and the condenser (1) and the heat dissipation water tank (9) enclose the condensing air duct.

3. The semi-trailer chiller unit of claim 1, wherein: The evaporation cavity (801) gradually decreases in volume from bottom to top, and the bottom inner side of the evaporation cavity (801) is arranged in an upward inclination, and the condensing air duct (803) gradually increases in volume from bottom to top.

4. The semi-trailer chiller unit of claim 3, wherein: The evaporator (5) is fixedly installed at the bottom of the evaporation cavity (801), the upper end of the evaporator (5) is arranged in an inclination away from the evaporation cavity (801), the evaporator (5) and the inner side wall of the evaporation cavity (801) form an evaporation air duct, the evaporation air duct gradually increases in volume from bottom to top, the upper part of the evaporation air duct is provided with an evaporation fan (6), and the heat preservation shell (8) is provided with an access hole (3) corresponding to the evaporation fan (6).

5. The semi-trailer chiller unit of claim 2, wherein: The evaporator (5) is internally provided with multiple groups of heat exchange coils, each group of heat exchange coils comprises coil one (501) and coil two (502) arranged in an interlacing mode, the multiple groups of coil one (501) are communicated with a group of refrigeration systems close to each other, and the multiple groups of coil two (502) are communicated with another group of refrigeration systems.

6. The semi-trailer chiller unit of claim 5, wherein: The evaporator (5) is internally provided with multiple groups of straight pipe sections arranged at equal intervals, each group of straight pipe sections comprises multiple straight pipe sections (5013) arranged in parallel and at equal intervals, the straight pipe sections (5013) in the two adjacent groups of straight pipe sections are arranged in an interlacing mode, the coil one (501) is formed by multiple straight pipe sections (5013) and bend pipe section one (5014) connected in sequence, and the coil two (502) is formed by multiple straight pipe sections (5013) and bend pipe section two (5023) connected in sequence.

7. The semi-trailer chiller unit of claim 6, wherein: The two ends of the first coil (501) are respectively provided with a refrigerant inlet one (5011) and a refrigerant outlet one (5012), the two ends of the second coil (502) are respectively provided with a refrigerant inlet two (5021) and a refrigerant outlet two (5022), a plurality of refrigerant inlets one (5011) are commonly connected with a total liquid inlet pipe one, a plurality of refrigerant outlets one (5012) are commonly connected with a total liquid outlet pipe one, the total liquid inlet pipe one and the total liquid outlet pipe one are communicated with a corresponding refrigeration system, a plurality of refrigerant inlets two (5021) are commonly connected with a total liquid inlet pipe two, a plurality of refrigerant outlets two (5022) are commonly connected with a total liquid outlet pipe two, and the total liquid inlet pipe two and the total liquid outlet pipe two are communicated with another refrigeration system.

8. The semi-trailer chiller unit of any one of claims 1 to 7, characterized by: The refrigeration system comprises a compressor (7), a condenser (1), an evaporator (5), an expansion valve two (21), an electromagnetic valve one (10) and an electromagnetic valve two (11), the high-pressure outlet (701) of the compressor (7) is communicated with the condenser (1) through the electromagnetic valve one (10), the condenser (1) is connected with the expansion valve two (21), the expansion valve two (21) is connected with the evaporator (5), the high-pressure outlet (701) of the compressor (7) is connected with the evaporator (5) through the electromagnetic valve two (11), and the outlet of the evaporator (5) is communicated with the low-pressure outlet (703) of the compressor (7).

9. The semi-trailer chiller unit of claim 8, wherein: The condenser (1) and the expansion valve two (21) are provided with an auxiliary heat exchange mechanism, the auxiliary heat exchange mechanism comprises a liquid storage tank (15), a drying filter (16), a plate heat exchanger (19) and an expansion valve one (18), the plate heat exchanger (19) is provided with a first heat exchange passage and a second heat exchange passage, the outlet of the condenser (1) is communicated with the liquid storage tank (15) through a one-way valve two (13), the liquid storage tank (15) is communicated with the drying filter (16), the outlet of the drying filter (16) is communicated with the second heat exchange passage through a pipeline one, the second heat exchange passage is connected with the expansion valve two (21) through an electromagnetic valve four (20), the outlet of the drying filter (16) is connected with the expansion valve one (18) through a pipeline two, the pipeline two is provided with an electromagnetic valve three (17), the expansion valve one (18) is communicated with the first heat exchange passage, and the outlet of the first heat exchange passage is communicated with the medium-temperature steam outlet (702) of the compressor (7).

10. The semi-trailer chiller unit of claim 9, wherein: The electromagnetic valve two (11) is communicated with the liquid storage tank (15) through a one-way valve three (14).

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