A heavy truck and air conditioner refrigerant pipeline thereof

Abstract

This utility model relates to a heavy-duty truck and its air conditioning refrigerant pipeline, belonging to the field of vehicle air conditioning technology. The air conditioning refrigerant pipeline includes a compressor discharge pipe connected between the compressor exhaust port and the condenser. The compressor discharge pipe has a recessed bend where both the inlet and the bottom bend are lower than the compressor exhaust port. This bend is used to retain liquid refrigerant that flows back from the condenser after the compressor stops, preventing liquid refrigerant from flowing back into and remaining in the compressor cavity. This utility model rationally stores static refrigerant after the compressor stops and the refrigerant liquefies, preventing excessive refrigerant from entering the compressor. This, in turn, prevents excessive refrigerant from vaporizing during the next compressor start-up, causing excessive bubbles in the lubricating oil and reducing lubrication. Ultimately, this improves the lifespan of the compressor bearings and moving parts.

Description

Technical Field

[0001] This utility model relates to a heavy truck and its air conditioning refrigerant pipeline, belonging to the field of vehicle air conditioning technology. Background Technology

[0002] For new energy heavy-duty trucks, the air conditioning system includes a compressor, condenser, expansion valve, evaporator, gas-liquid separator, and refrigerant piping that connects these components in series to form a refrigerant refrigeration cycle. Cab-over trucks typically have a layout with the cab above and the engine compartment below. The evaporator is located behind the dashboard instruments, and the compressor, directly driven by the engine via a belt, is generally positioned lower than the other components in the refrigerant cycle. Even in pure electric heavy-duty trucks, due to space constraints, the electric compressor must be located below the cab. When the air conditioning system is running, the compressor and its intake and exhaust pipes contain gaseous refrigerant; simultaneously, the refrigerant contains a certain proportion of lubricating oil to ensure adequate lubrication of the pistons, bearings, and other moving parts of the compressor during operation.

[0003] During the operation of an air conditioning system, the refrigerant exists in different phases at different locations. When the compressor stops running, the refrigerant in the air conditioning system is converted to a liquid state. Since the compressor is located at the lowest point of the air conditioning system's refrigeration cycle, some of the refrigerant in the refrigerant lines and condenser flows into the compressor cavity in liquid form. When the compressor starts again, the liquid refrigerant in the compressor cavity instantly converts to a gaseous state, and the specific volume of the refrigerant increases instantaneously. This causes the lubricating oil mixed in the refrigerant to generate bubbles, severely affecting the lubrication of components such as compressor bearings. At the same time, the repeated generation of bubbles in the lubricating oil accelerates the aging process of the internal moving parts of the compressor, resulting in a significant reduction in the lifespan of the internal bearings and other moving parts. Utility Model Content

[0004] The purpose of this invention is to provide a heavy-duty truck and its air conditioning refrigerant pipeline to solve the problem that the lubricating oil will produce air bubbles after the air conditioner of the heavy-duty truck is restarted, resulting in poor lubrication.

[0005] To achieve the above objectives, the solution of this utility model includes:

[0006] This utility model discloses an air conditioning refrigerant pipeline, including a compressor exhaust pipeline connected between the compressor exhaust port and the condenser. The compressor exhaust pipeline has a sunken bend with both the inlet and the bottom bend lower than the compressor exhaust port, which is used to retain the liquid refrigerant that flows back from the condenser direction after the compressor stops, thus preventing the liquid refrigerant from flowing back into and remaining in the compressor cavity.

[0007] Furthermore, the sinking bend inlet is directly or through a transition bend connected to the compressor exhaust port.

[0008] Furthermore, the sunken bend includes a U-shaped bend section. The end of the bend section facing the compressor is connected to the compressor exhaust port through the bend. The end of the bend section facing the condenser reaches the height of the condenser inlet through a vertical extension pipe extending vertically, and then connects to the condenser inlet through a horizontal extension pipe extending horizontally.

[0009] Furthermore, the compressor suction line connecting the compressor suction port and the gas-liquid separator includes an inclined pipe section with a certain downward inclination angle toward the gas-liquid separator, which is used to allow the gaseous refrigerant in the compressor suction line to flow back into the gas-liquid separator after liquefaction when the compressor stops.

[0010] Furthermore, the internal volume of the sunken bend is more than 6% of the internal volume of the compressor exhaust pipe and the condenser.

[0011] The beneficial effects of this utility model are as follows:

[0012] This invention utilizes the phase change characteristics of refrigerants to design a compressor suction and discharge pipeline structure. This structure effectively stores static refrigerant after the compressor stops and the refrigerant liquefies, preventing excessive refrigerant from entering the compressor. This, in turn, prevents excessive refrigerant from vaporizing during the next compressor start-up, thus avoiding the generation of numerous bubbles in the lubricating oil within the refrigerant and reducing lubrication effectiveness. Ultimately, this extends the lifespan of the compressor bearings and moving parts.

[0013] The solution of this utility model does not require the addition of one-way valves or other parts to prevent refrigerant from flowing back into the compressor, thus effectively controlling the cost of the thermal management system.

[0014] This utility model discloses a heavy-duty truck, which includes an air conditioning system. The air conditioning system includes a compressor and a condenser connected to the compressor exhaust port through a compressor exhaust pipe (i.e., it includes a compressor and a condenser, and the condenser is connected to the compressor exhaust port through a compressor exhaust pipe). The compressor exhaust pipe has a sunken bend with both its inlet and the bottom bend lower than the compressor exhaust port, which is used to retain the liquid refrigerant that flows back from the condenser after the compressor stops, thus preventing the liquid refrigerant from flowing back into and remaining in the compressor cavity.

[0015] Furthermore, the compressor exhaust port is directly or via a transitional bend to the sinking bend inlet.

[0016] Furthermore, the sunken bend includes a U-shaped bend section. The end of the bend section facing the compressor is connected to the compressor exhaust port through the bend. The end of the bend section facing the condenser reaches the height of the condenser inlet through a vertical extension pipe extending vertically, and then connects to the condenser inlet through a horizontal extension pipe extending horizontally.

[0017] Furthermore, the compressor suction pipe connecting the compressor suction port to the gas-liquid separator includes an inclined pipe section with a certain downward inclination angle toward the gas-liquid separator, which is used to allow the gaseous refrigerant in the compressor suction pipe to flow back into the gas-liquid separator after liquefaction when the compressor stops.

[0018] Furthermore, the internal volume of the sunken bend is more than 6% of the internal volume of the compressor exhaust pipe and the condenser.

[0019] The heavy-duty truck of this invention, after applying the air conditioning refrigerant pipeline of this invention, has the same beneficial effects as the air conditioning refrigerant pipeline. Attached Figure Description

[0020] Figure 1 This is a diagram of the refrigeration circulation pipeline connection structure of a heavy-duty truck air conditioning system in the existing technology;

[0021] Figure 2 This is a diagram of the refrigeration circulation pipeline connection structure of a heavy-duty truck air conditioning system from another perspective in existing technology;

[0022] Figure 3 This is a structural diagram of the refrigeration circulation pipeline connection of the heavy-duty truck air conditioning system of this utility model.

[0023] The diagram includes: compressor 1; gas-liquid separator 2; condenser 3; evaporator 4; downstream pipeline 10; second pipeline 11; compressor suction pipeline 12; inclined pipe section 121; upstream pipeline 20; first pipeline 21; upward pipeline 211; horizontal straight pipe 212; compressor discharge pipeline 22; downward bend section 221; bend bottom section 222; vertical extension pipe 223; and horizontal extension pipe 224. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and embodiments.

[0025] The current design scheme's air conditioning system refrigeration cycle is as follows: Figure 1 , 2 As shown, the system includes an evaporator 4 with an integrated expansion valve located in the cockpit. The liquid inlet of the evaporator 4 is connected to the condenser 3 via an upstream pipe 20. The condenser 3 is then connected to the exhaust port of the compressor 1 via a first pipe 21, which serves as the compressor's liquid discharge pipe. The exhaust port of the evaporator 4 is connected to a gas-liquid separator 2 via a downstream pipe 10. The gas-liquid separator 2 is connected to the suction port of the compressor 1 via a second pipe 11, which serves as the compressor's liquid inlet pipe. The evaporator is located in the cockpit, and the condenser is located behind the air intake grille below the cockpit to achieve condensation by impact. The compressor, avoiding the engine behind the condenser, is located at the lowest point in the entire air conditioning system. In the prior art, such as... Figure 1As shown, the first pipe 21 is the compressor discharge pipe, connecting the compressor discharge port and the condenser 3. It employs the most direct and shortest pipe routing method, connecting an upward pipe 211 from the compressor discharge port, and then connecting to the condenser 3 via a horizontal straight pipe 212. The second pipe 11 is the compressor suction pipe. To facilitate connection and provide some assembly tolerances, the first pipe uses a flexible hose, forming an upward-arched inverted U-shape after connecting the gas-liquid separator 2 and the compressor suction port. With this pipe design, some refrigerant in the first pipe 21, the second pipe 11, and the condenser 3 will flow back into the compressor 1 cavity when the air conditioning system is not running.

[0026] Air conditioning refrigerant piping implementation method 1:

[0027] This embodiment improves the shape of the first pipe 21 in the prior art described above. In this embodiment, the improved first pipe functions the same as the first pipe 21 in the prior art, both serving as compressor exhaust pipes to connect the compressor exhaust port and the condenser 3; the only difference is the pipe shape. In this embodiment, the improved first pipe is as follows: Figure 3 As shown, this is referred to as compressor exhaust pipe 22; other reference numerals for air conditioning system components consistent with the prior art are shown in this embodiment and the accompanying drawings of this embodiment. Figure 3 It will continue to be used in China.

[0028] The compressor discharge pipe 22, connecting the compressor discharge port and the condenser 3, includes a recessed bend where both the inlet and the bottom bend are lower than the compressor discharge port. This recessed bend is used to retain the refrigerant that flows back after the compressor 1 stops, preventing refrigerant from remaining inside the compressor 1 cavity and expanding into a gaseous state, generating bubbles in the lubricating oil when the compressor 1 starts. The recessed bend is most effective when it is close to the compressor discharge port. The compressor discharge port is directly or indirectly connected to the recessed bend inlet on the vertical straight pipe on one side of the U-shaped recessed bend, ensuring that the recessed bend inlet is also lower than the compressor discharge port.

[0029] Specifically, such as Figure 3 As shown, the compressor exhaust pipe 22 includes a downward bend section 221 that bends downward from the compressor exhaust port. The downward bend section 221 smoothly transitions to the bottom bend section 222. One end of the bottom bend section 222 is directly connected to the downward outlet of the downward bend section 221 or indirectly connected through a short straight pipe. The other end of the bottom bend section 222 is connected to a vertical extension pipe 223 that extends vertically. The vertical extension pipe 223 is connected to a horizontal extension pipe 224 that extends horizontally through a bend, and is connected to the inlet of the condenser 3 at the same horizontal level through the horizontal extension pipe 224.

[0030] Among these, the section of pipe between the lower bend section 221 and the vertical extension pipe 223, which is horizontally lower than the exhaust port of the compressor 1, constitutes the aforementioned sunken bend section; or the bottom bend section 222 and the vertical straight pipes on both sides that are horizontally lower than the exhaust port of the compressor 1 constitute the aforementioned sunken bend section, the upper pipe opening of the vertical straight pipe near the compressor constitutes the sunken bend inlet, and the lower bend section 221 constitutes the aforementioned transition bend that indirectly connects the compressor exhaust port and the sunken bend inlet.

[0031] Air conditioning refrigerant piping implementation method 2:

[0032] This embodiment further improves the shape of the second pipe 11 in the aforementioned prior art based on embodiment 1 of the air conditioning refrigerant piping. In this embodiment, the improved second pipe has the same function as the second pipe 11 in the aforementioned prior art, both serving as the compressor suction pipe for connecting the gas-liquid separator 2 and the compressor suction port; the only difference is the pipe shape. The improved second pipe in this embodiment is as follows: Figure 3 As shown, this is referred to as the compressor suction line 12; other reference numerals for air conditioning system components consistent with the prior art are shown in this embodiment and the accompanying drawings of this embodiment. Figure 3 It will continue to be used in China.

[0033] like Figure 3 As shown, in this embodiment, the compressor suction line 12 avoids the inverted U-shape of the second line 11 arching upwards in the prior art. The compressor suction line 12, which connects to the compressor 1 from the gas-liquid separator 2, includes an inclined pipe section 121 with a certain downward inclination angle toward the gas-liquid separator 2, to ensure that the gaseous refrigerant in the compressor suction line 12 flows back into the gas-liquid separator 2 after liquefaction.

[0034] Necessary vertical pipe sections are provided at the suction port of compressor 1 and the outlet of gas-liquid separator 2 to ensure that the inclined pipe section 121 has a sufficient downward inclination angle toward gas-liquid separator 2, so as to ensure that the liquefied refrigerant has sufficient fluidity and flows into gas-liquid separator 2.

[0035] Air conditioning refrigerant piping implementation method 3:

[0036] In this embodiment, the refrigerant used in the air conditioning system is R134a. During operation, the specific volume of refrigerant in the compressor 1 to condenser 3 and in the compressor 1 to evaporator 4 ranges from 15-70 L / kg. When the air conditioning system is stopped, the specific volume of refrigerant is ≤1 L / kg. Therefore, as an optimal implementation of an air conditioning system using R134a refrigerant, based on embodiment 2 of the air conditioning refrigerant piping, the internal volume of the recessed bend in the compressor discharge pipe 22 is at least 6% of the internal volume of the compressor discharge pipe 22 and the condenser 3. This ensures that the gaseous refrigerant in the condenser 3 and the compressor discharge pipe 22, after liquefaction, remains within the recessed bend and does not flow back into the compressor 1.

[0037] Furthermore, when compressor 1 stops in the high-speed range, it needs to reduce its speed to the minimum speed and maintain it for a certain period of time, such as 10 seconds, to ensure that the backflow impact caused by the refrigerant turning into a liquid phase change when compressor 1 stops is as small as possible.

[0038] Heavy truck implementation method:

[0039] This embodiment of a heavy-duty truck includes a cab located above and an engine compartment located below, with an air intake grille at the front of the engine compartment. The air conditioning system of this heavy-duty truck adopts the air conditioning refrigerant piping system described in embodiments 1, 2, or 3; wherein the evaporator 4 is located behind the dashboard in the cab and connected to the air intake duct of the cab, the condenser 3 is located behind the air intake grille, below the evaporator 4, and the compressor 1 is located inside the engine compartment at the lowest point of the entire air conditioning refrigerant piping system; the specific details of the air conditioning refrigerant piping system have been clearly described in embodiments 1, 2, or 3, and will not be repeated here.

Claims

1. An air conditioning refrigerant pipeline, comprising a compressor discharge pipeline connected between the compressor discharge port and the condenser, characterized in that, The compressor exhaust pipe has a sunken bend with both its inlet and bottom lower than the compressor exhaust port. This bend is used to retain the liquid refrigerant that flows back from the condenser after the compressor stops, preventing the liquid refrigerant from flowing back into and remaining in the compressor cavity.

2. The air conditioning refrigerant pipeline according to claim 1, characterized in that, The sinking bend inlet is directly or through a transition bend connected to the compressor exhaust port.

3. The air conditioning refrigerant pipeline according to claim 2, characterized in that, The sunken bend includes a U-shaped bend section. The end of the bend section facing the compressor is connected to the compressor exhaust port through the bend. The end of the bend section facing the condenser is connected to the height of the condenser inlet through a vertical extension pipe extending vertically, and then connected to the condenser inlet through a horizontal extension pipe extending horizontally.

4. The air conditioning refrigerant piping according to claim 1, characterized in that, The compressor suction line connecting the compressor suction port and the gas-liquid separator includes an inclined pipe section with a certain downward inclination angle toward the gas-liquid separator, which is used to allow the gaseous refrigerant in the compressor suction line to flow back into the gas-liquid separator after liquefaction when the compressor stops.

5. The air conditioning refrigerant pipeline according to claim 1, characterized in that, The internal volume of the sunken bend is more than 6% of the internal volume of the compressor exhaust pipe and the condenser.

6. A heavy-duty truck, comprising an air conditioning system, the air conditioning system including a compressor and a condenser, the condenser being connected to the compressor exhaust port via a compressor exhaust pipe, characterized in that, The compressor exhaust pipe has a sunken bend with both its inlet and bottom lower than the compressor exhaust port. This bend is used to retain the liquid refrigerant that flows back from the condenser after the compressor stops, preventing the liquid refrigerant from flowing back into and remaining in the compressor cavity.

7. The heavy-duty truck according to claim 6, characterized in that, The compressor exhaust port is connected directly or via a transitional bend to the sinking bend inlet.

8. The heavy-duty truck according to claim 7, characterized in that, The sunken bend includes a U-shaped bend section. The end of the bend section facing the compressor is connected to the compressor exhaust port through the bend. The end of the bend section facing the condenser is connected to the height of the condenser inlet through a vertical extension pipe extending vertically, and then connected to the condenser inlet through a horizontal extension pipe extending horizontally.

9. The heavy-duty truck according to claim 6, characterized in that, The compressor suction pipe connecting the compressor suction port to the gas-liquid separator includes an inclined pipe section with a certain downward tilt angle toward the gas-liquid separator, which is used to allow the gaseous refrigerant in the compressor suction pipe to liquefy and flow back into the gas-liquid separator after the compressor stops.

10. The heavy-duty truck according to claim 6, characterized in that, The internal volume of the sunken bend is more than 6% of the internal volume of the compressor exhaust pipe and the condenser.

Images