A grain harvester and a control method thereof

Abstract

The application provides a grain harvester and a control method thereof, and belongs to the technical field of grain drying. In the grain harvester, the heat exchange pipe directly passes through the air supply pipe, so that the tail gas / air flowing through the air supply pipe directly exchanges heat with the refrigerant medium in the heat exchange pipe, thereby reducing the length of the heat transfer path, reducing heat loss, and improving the heat exchange efficiency. At the same time, in order to compensate for the pressure drop caused by the heat exchange pipe passing through the air supply pipe, the tube cavity of the air supply pipe is communicated with the gas storage cavity through the opening in the wall of the air supply pipe, so that the gas storage cavity stores gas when the gas pressure of the tail gas / air is relatively large, and supplies gas to the tube cavity when the gas pressure is relatively small, thereby relatively stabilizing the gas pressure in the tube cavity, compensating for the pressure drop caused by the heat exchange pipe, and improving the turbocharging effect. Therefore, the grain harvester has the advantages of good turbocharging effect and high heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of grain drying technology, and in particular to a grain harvester and its control method. Background Technology

[0002] Previous research (ZL2023103579960 - Heat Exchanger, Combine Harvester Exhaust Heat Recovery Device, and Combine Harvester) proposed a heat exchanger suitable for grain harvesters that can recover engine waste heat from turbochargers, enabling the use of this waste heat in grain drying and reducing energy consumption. In this heat exchanger, a cold medium (e.g., heat exchange water) flows between two layers of corrugated pipes, while engine exhaust gas flows within an expandable inner cylinder inside the inner corrugated pipe. A heat pipe connecting the inner corrugated pipe and the inner cylinder serves as the heat transfer medium. In this heat exchanger, the inner cylinder is compressed by the spring, which narrows the passage for the engine exhaust gas to flow through the inner cylinder and forces the engine exhaust gas to be depressurized. This results in a decrease in the flow rate and speed of the exhaust gas flowing from the engine into the turbine chamber, which in turn leads to a poorer turbocharging effect. At the same time, the coolant needs to exchange heat with the engine exhaust gas through heat pipes. Not only is the heat transfer path long, but the heat loss is also large, which requires multiple heat exchangers to compensate for the loss, thus increasing the cost of the entire heat exchange system. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a grain harvester and its control method that overcome or at least partially solve the above problems, and can solve the problems of poor turbocharging effect and low heat exchange efficiency caused by existing heat exchange systems.

[0004] Specifically, the present invention provides a grain harvester, comprising:

[0005] An engine assembly comprising an engine, a first heat exchanger, and a turbocharger connected in sequence, the first heat exchanger being connected between the exhaust outlet of the engine and the turbine chamber inlet of the turbocharger to cause exhaust gas exiting from the exhaust outlet to heat a coolant flowing through the first heat exchanger.

[0006] A lifting-drying device includes a feeding pipe for conveying grains, a feeding auger extending along the length of the pipe inside the feeding pipe, and a second heat exchanger connected to the feeding pipe for blowing air along the feeding direction. The second heat exchanger is configured to guide air heated by the cold medium into the feeding pipe.

[0007] A refrigeration system, the refrigeration system comprising a refrigerant container for storing the refrigerant, and a refrigerant pump for pumping the refrigerant in sequence between a flow valve, an intercooler, a first heat exchanger, a second heat exchanger, and the refrigerant container; and,

[0008] Both the first heat exchanger and the second heat exchanger include an outer shell, an inner liner tube, and a gas supply tube that are sequentially fitted together from the outside to the inside. A refrigerant cavity for flowing through a refrigerant medium is defined between the outer shell and the inner liner tube. A heat exchange tube that passes through the gas supply tube and communicates with the refrigerant cavity is connected to the inner liner tube. A gas storage cavity that communicates with the cavity of the gas supply tube through an opening in the tube wall is defined between the inner liner tube and the gas supply tube.

[0009] Preferably, the inner liner is made of elastic rubber material and the air supply pipe is made of corrugated metal material, so that both can expand and contract in the radial direction.

[0010] Preferably, the outer casing is a sleeve shape with necked ends; and,

[0011] The air supply pipe has a central cavity that is of equal diameter to the two ends of the outer shell, and an annular groove cavity formed in the folds; wherein the annular groove cavity has a constricted portion located between the groove opening and the belly, and its axial width gradually increases from the constricted portion to both sides, and the radial distance between the constricted portion and the groove opening is less than the distance between the constricted portion and the belly.

[0012] Preferably, the heat exchange tube passes through the gas supply pipe through the opening in the tube wall, and a spiral groove extending along the length of the tube is formed on the outer tube wall of the heat exchange tube, with the two ends of the spiral groove located on opposite sides of the gas storage chamber.

[0013] Preferably, the inner liner extends vertically, and there are multiple heat exchange tubes, all of which extend horizontally and are spaced apart vertically; furthermore...

[0014] Axial partitions extending vertically are formed on both the left and right sides of the refrigerant cavity to divide the refrigerant cavity into a left sub-cavity connected to the left end of each heat exchange tube and a right sub-cavity connected to the right end of each heat exchange tube. A left circumferential partition, vertically spaced between two connected heat exchange tubes, is formed in the left sub-cavity, and a right circumferential partition, vertically spaced between two connected heat exchange tubes, is formed in the right sub-cavity. The left and right circumferential partitions are staggered vertically and have one heat exchange tube between them, so that the multiple heat exchange tubes and the refrigerant cavity are divided into a loop-shaped flow channel.

[0015] A second aspect of the present invention provides a control method applicable to the above-described grain harvester, comprising:

[0016] The temperature of the exhaust gas flowing through the first heat exchanger in the grain harvester, the flow rate and pressure of the cooling medium, and the temperature of the cooling medium flowing through the second heat exchanger in the grain harvester are obtained.

[0017] In response to the start command received sequentially or simultaneously by the engine and the feeding auger in the grain harvester, the grain harvester is controlled to operate according to a first control strategy; wherein in the first control strategy, the refrigerant pump in the grain harvester operates at a first set speed, and the flow valve in the grain harvester opens at a first set opening degree;

[0018] When the grain harvester is operating according to the first control strategy, the exhaust gas temperature is higher than the first temperature threshold, and the refrigerant temperature is lower than the second temperature threshold, the opening of the flow valve is increased to increase the refrigerant flow; and the first control strategy is modified by increasing the first set opening.

[0019] When the grain harvester is operating according to the first control strategy, the exhaust gas temperature is lower than the first temperature threshold, and the refrigerant temperature is higher than the second temperature threshold, the speed of the refrigerant pump is increased to increase the refrigerant pressure; and the first control strategy is modified by increasing the first set speed.

[0020] After the first control strategy is corrected, the next time the engine and the feeding auger are started, they will operate according to the corrected first control strategy.

[0021] Preferably, after the grain harvester operates according to the first control strategy, it further includes:

[0022] Obtain the first gas pressure of the exhaust gas flowing through the first heat exchanger;

[0023] After the first air pressure exceeds the first pressure threshold, the speed of the refrigerant pump is reduced;

[0024] After the first gas pressure falls below the first pressure threshold, the speed of the refrigerant pump is increased.

[0025] Preferably, after the grain harvester operates according to the first control strategy, it further includes:

[0026] Obtain the second air pressure and air temperature of the air flowing out of the second heat exchanger;

[0027] After the air temperature falls below the third temperature threshold, the opening of the flow valve is increased;

[0028] After the air temperature is higher than the third temperature threshold and the second air pressure is higher than the second pressure threshold, the opening of the flow valve is increased, the speed of the refrigerant pump is increased, and the second air pressure continues to increase.

[0029] Preferably, before the engine and the feeding auger are started, the following steps are also included:

[0030] With the engine running and the feeding auger off, the grain harvester is controlled to operate according to a second control strategy; wherein the second control strategy includes:

[0031] Obtain the exhaust gas temperature;

[0032] After the exhaust gas temperature exceeds the fourth temperature threshold, the refrigerant pump is controlled to operate at the first set speed, and the opening degree of the flow valve is the first set opening degree; wherein, the fourth temperature threshold is lower than the first temperature threshold.

[0033] If the exhaust gas temperature is equal to or lower than the fourth temperature threshold, the refrigerant pump is shut down.

[0034] Preferably, after modifying the first control strategy, the method further includes:

[0035] After the grain harvester operates according to the modified first control strategy, it is determined whether the refrigerant temperature is lower than the second temperature threshold when the exhaust gas temperature is higher than the first temperature threshold.

[0036] If the temperature is below the threshold, then the first temperature threshold and the fourth temperature threshold are reduced.

[0037] The beneficial effects of this invention are:

[0038] In this invention's grain harvester, the heat exchange tube passes directly through the air supply pipe, allowing the exhaust gas / air flowing through the air supply pipe to directly exchange heat with the cooling medium inside the heat exchange tube. This reduces the length of the heat transfer path, minimizes heat loss, and improves heat exchange efficiency. Simultaneously, to compensate for the pressure drop caused by the heat exchange tube passing through the air supply pipe, an opening in the pipe wall connects the air supply pipe's cavity to a gas storage chamber. This gas storage chamber stores gas when the exhaust gas / air pressure is high and replenishes it when the pressure is low, thus stabilizing the gas pressure within the chamber and compensating for the pressure drop caused by the heat exchange tube, thereby improving the turbocharging effect. Therefore, this invention's grain harvester has the advantages of good worm gear turbocharging and high heat exchange efficiency.

[0039] In addition, the pipe wall opening and the air storage chamber form a resonant cavity around the pipe cavity. This resonant cavity can also achieve noise reduction and silencing during the exhaust gas / air emission process. Therefore, as an unexpected technical effect of the grain harvester of the present invention, it also has the advantage of low operating noise.

[0040] Furthermore, when the grain harvester of the present invention is in operation and the air storage chamber is filled with exhaust gas / compressed air, the exhaust gas / compressed air in the air storage chamber will apply pressure to the constricted portion of the annular cavity, causing the constricted portion to close and achieving the purpose of maintaining pressure. This is to prepare for air replenishment when the air pressure in the central cavity decreases. In particular, the lower the air pressure in the air storage chamber, the larger the opening of the constricted portion will be, thereby achieving better air replenishment. Therefore, the grain harvester of the present invention has the advantages of good worm gear pressurization effect and high heat exchange efficiency.

[0041] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0042] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0043] Figure 1 This is a schematic diagram of the flow direction of airflow and cooling medium in the operating state of a grain harvester according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of a heat exchanger according to an embodiment of the present invention;

[0045] Figure 3 yes Figure 2 Front view of the intermediate heat exchanger;

[0046] Figure 4 yes Figure 3 A cross-sectional view of the intermediate heat exchanger (AA section).

[0047] Figure 5 yes Figure 3 BB cross-sectional view of the intermediate heat exchanger;

[0048] Figure 6 yes Figure 4 Enlarged view of a portion of the heat exchanger at point C.

[0049] in:

[0050] Engine assembly - 100, engine - 110, first heat exchanger - 120, turbocharger - 130, turbine housing - 131;

[0051] Material lifting and drying device-200, feeding pipe-210, feeding auger-220, second heat exchanger-230;

[0052] Refrigeration system - 300, refrigerant container - 310, flow valve - 320, intercooler - 330, refrigerant pump - 340;

[0053] Heat exchanger structure - 400, outer shell - 410, inner liner tube - 420, air supply pipe - 430, central cavity - 431, annular groove cavity - 432, constriction section - 433, refrigerant cavity - 440, heat exchange tube - 450, air storage cavity - 460, axial partition - 470, left circumferential partition - 481, right circumferential partition - 482, refrigerant inlet - 491, refrigerant outlet - 492. Detailed Implementation

[0054] In the description of this embodiment, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0055] Unless otherwise expressly specified and limited, the terms "set up," "install," "connect," "link," "fix," and "couple" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0057] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] like Figure 1 The diagram shown illustrates the flow direction of airflow and cooling medium in the operating state of the grain harvester of the present invention. Figure 2-5The diagram shows a schematic of the heat exchanger in the grain harvester of the present invention. In an embodiment of the grain harvester of the present invention, the grain harvester includes an engine assembly 100, a lifting-drying device 200, and a refrigeration system 300. The engine assembly 100 includes an engine 110, a first heat exchanger 120, and a turbocharger 130 connected in sequence. The first heat exchanger 120 is connected between the exhaust outlet of the engine 110 and the inlet of the turbine chamber 131 of the turbocharger 130 to heat the exhaust gas discharged from the exhaust outlet and allow it to flow through the cold medium of the first heat exchanger 120. The lifting-drying device 200 includes a feed pipe 210 for conveying grain. A feed auger 220 extending along the length of the pipe is disposed inside the feed pipe 210. A second heat exchanger 230 is also connected to the feed pipe 210 to blow air along the feeding direction. The second heat exchanger 230 is configured to guide the air heated by the cold medium into the feed pipe 210. The refrigeration system 300 includes a refrigerant container 310 for storing a refrigerant medium, and a refrigerant pump 340 for pumping the refrigerant medium to circulate sequentially among a flow valve 320, an intercooler 330, a first heat exchanger 120, a second heat exchanger 230, and the refrigerant container 310. The first heat exchanger 120 and the second heat exchanger 230 employ the same heat exchanger structure 400, which includes, from the outside in, a shell 410, an inner liner tube 420, and a gas supply pipe 430 sequentially fitted together. A refrigerant cavity 440 for flowing refrigerant is defined between the shell 410 and the inner liner tube 420. A heat exchange tube 450, passing through the gas supply pipe 430 and communicating with the refrigerant cavity 440, is connected to the inner liner tube 420. A gas storage cavity 460, communicating with the cavity of the gas supply pipe 430 through an opening in its wall, is defined between the inner liner tube 420 and the gas supply pipe 430.

[0059] In the above embodiment, the intake duct of the turbocharger 130 is connected to the intake port of the intercooler 330 to allow heat exchange between the gas from the turbocharger 130 and the cooling medium of the intercooler 330. Turbocharging is a technology that uses the exhaust gas generated by the engine 110 to drive air compression. The turbocharger 130 uses the exhaust gas from the engine 110 as power to drive the turbine (located in the exhaust manifold) within the turbine chamber 131. The turbine then drives a coaxial impeller (located in the intake manifold), which compresses the fresh air delivered from the intake manifold and sends it into the piston cylinder of the engine 110. As the engine 110 speed increases, the exhaust gas velocity and turbine speed also increase synchronously, increasing the degree of air compression and consequently increasing the intake volume of the engine 110, thus increasing the output power of the engine 110. However, if the high-temperature compressed air is directly introduced into the engine 110, the excessively high air temperature can cause engine knocking, or even damage and stalling. The intercooler 330 serves to cool the air. The high-temperature air passes through the intercooler 330 before entering the engine 110. The turbocharger 130 compresses the air, transforming it from a normal-temperature, normal-pressure gas into a high-temperature, high-pressure gas. The intercooler 330 cools this high-temperature gas and also utilizes the heat from the turbocharged air. For example, in some embodiments of the grain harvester of this invention, the intercooler 330 is a water-cooled intercooler 330. The water-cooled intercooler 330 uses circulating cooling water as the cooling medium to cool the air flowing through it. The advantages of the water-cooled intercooler 330 are high cooling efficiency and flexible installation location, eliminating the need for long connecting pipes.

[0060] In the above embodiments, the lifting-drying device 200 adds a wind-powered drying function compared to traditional lifting devices. Traditional lifting devices mainly include a lifting device, a conveying pipe or belt, a fan system, a collection bin, and an adjustment device. The lifting device is the core component and typically consists of rotating blades or a propeller (e.g., the feeding auger 220 used in the grain harvester of this invention). It generates airflow or mechanical force through rotation to throw the grain upwards or transport it to a designated location. The design of the lifting device needs to ensure efficient conveying while minimizing damage to the grain. The material generated by the lifting device is conveyed to the collection bin or transport vehicle via the conveying pipe or belt. The belt is usually made of wear-resistant material to ensure it can withstand large amounts of grain during harvesting and maintain operation for extended periods. Some lifting devices are also equipped with a fan system that uses wind power to blow the grain from the lifting device to the conveyor belt or collection bin. This fan system is typically used to enhance material flowability and reduce grain compaction or accumulation. The harvester's hopper is a container used to store the grain that has been hoisted up, and it is usually connected to the hoisting device. As the hoist and conveying system transport grain to the hopper, the capacity inside gradually increases until it is full or needs to be unloaded. The hoisting device is usually equipped with adjustable devices to adjust parameters such as conveying speed, angle, or wind speed. These adjustments can be optimized according to the nature of different crops, environmental conditions, and types of grain to improve harvesting efficiency and reduce grain loss. In operation, after harvesting, the grain enters the hoisting device: After threshing and cleaning, the grain is fed into the hoist by mechanical vibration or screening devices. The hoist lifts the grain: The hoist usually consists of rotating blades or other mechanical devices that lift the grain to a set height through rotation or pushing motion. Conveying to the collection area: The lifted grain is transported to the hopper via belt, pipe, or pneumatic system or directly into a transport vehicle. Grain collection and storage: The hopper or transport vehicle receives the grain and prepares it for transportation or further processing. Unlike traditional lifting devices, in the embodiment of the grain harvester of the present invention, the feeding pipe 210 is provided with a plurality of air outlets spaced apart in the axial direction, and the air outlet of the second heat exchanger 230 is connected to these air outlets, so as to cause the air or compressed air flowing through the second heat exchanger 230 to be blown into the feeding pipe 210 from the air outlets to dry the grain in the feeding pipe 210.

[0061] In the above embodiments, the refrigerant container 310 in the refrigeration system 300 not only stores the refrigerant but also dissipates heat from it. This is especially crucial when the refrigerant remains at a high temperature after flowing out of the second heat exchanger 230. A refrigerant is a medium used to transfer heat in a refrigeration cycle system. Refrigerants possess specific physical and chemical properties, enabling them to change their state (liquid and gaseous) under low and high temperature conditions, thereby absorbing and releasing heat. Common refrigerants include Freon series, ammonia, alkanes, and carbon dioxide. The main functions of refrigerant in a refrigeration system 300 include: heat absorption—the refrigerant absorbs heat in the evaporator, lowering the temperature of the surrounding air or water; heat transfer—the refrigerant transfers the absorbed heat to the condenser via the compressor and then releases it into the external environment; and pressure and temperature regulation—under the action of a throttling valve or expansion valve, the refrigerant can regulate pressure and temperature between the evaporator and condenser to achieve a refrigeration cycle. When selecting a refrigerant, its physical properties (e.g., boiling point, freezing point, heat capacity), chemical properties (ozone depletion potential, global warming potential), safety, and environmental friendliness must be considered. In recent years, with increasing environmental awareness, some traditional refrigerants have been phased out, gradually shifting towards low-temperature, environmentally friendly alternatives. Common refrigerants and their characteristics include:

[0062] 1. Freon series (R-22, R-410A, etc.): Commonly used in household and commercial air conditioning systems, it has good cooling effect and heat transfer performance, but has a high potential to damage the ozone layer.

[0063] 2. Ammonia (NH3): Used in some industrial and commercial refrigeration systems 300, it has high refrigeration performance, but it is toxic to the human body.

[0064] 3. Alkanes (such as propane, isobutane, etc.): Environmentally friendly refrigerants used in some small refrigeration equipment.

[0065] 4. Carbon dioxide (CO2): An environmentally friendly refrigerant with zero ozone depletion potential and low global warming potential, it is increasingly being used in some high-efficiency and energy-saving refrigeration systems.

[0066] Choosing the right refrigerant is an important consideration in the design and operation of a refrigeration system 300, as it affects not only cooling performance and energy efficiency, but also environmental friendliness and safety.

[0067] In the above embodiments, the harvesting process of the grain harvester of the present invention includes:

[0068] S100, acquire the exhaust gas temperature of the exhaust gas flowing through the first heat exchanger 120 in the grain harvester, as well as the refrigerant flow rate and refrigerant pressure of the refrigerant medium, and the refrigerant temperature of the refrigerant medium flowing through the second heat exchanger 230 in the grain harvester.

[0069] S200, in response to the start command received sequentially or simultaneously by the engine 110 and the feeding auger 220 in the grain harvester, the grain harvester is controlled to operate according to a first control strategy; wherein in the first control strategy, the refrigerant pump 340 in the grain harvester operates at a first set speed, and the flow valve 320 in the grain harvester is opened at a first set opening degree.

[0070] S300, when the grain harvester is operating according to the first control strategy, the exhaust gas temperature is higher than the first temperature threshold, and the refrigerant temperature is lower than the second temperature threshold, the opening of the flow valve 320 is increased to increase the refrigerant flow; and the first control strategy is modified by increasing the first set opening.

[0071] S400, when the grain harvester is operating according to the first control strategy, the exhaust gas temperature is lower than the first temperature threshold, and the refrigerant temperature is higher than the second temperature threshold, the rotation speed of the refrigerant pump 340 is increased to increase the refrigerant pressure; and the first control strategy is modified by increasing the first set rotation speed.

[0072] S500, after the first control strategy is corrected, the next time the engine 110 and the feeding auger 220 are started, they will operate according to the corrected first control strategy.

[0073] The first and second temperature thresholds are both range values, allowing the exhaust gas temperature and refrigerant temperature to fluctuate within the range, thus expanding the environmental conditions under which the grain harvester of the present invention can operate normally and improving its applicability.

[0074] Based on this, in the above embodiments, the grain harvester of the present invention uses a heat exchange tube 450 that passes directly through the air supply pipe 430, allowing the exhaust gas / air flowing through the air supply pipe 430 to directly exchange heat with the cooling medium inside the heat exchange tube 450. This reduces the length of the heat transfer path, reduces heat loss, and improves heat exchange efficiency. Simultaneously, to compensate for the pressure drop caused by the heat exchange tube 450 passing through the air supply pipe 430, an opening is made in the pipe wall of the air supply pipe 430, connecting the cavity of the air supply pipe 430 to the air storage chamber 460. The air storage chamber 460 stores air when the exhaust gas / air pressure is high and replenishes air into the cavity when the pressure is low, thus stabilizing the air pressure within the cavity and compensating for the pressure drop caused by the heat exchange tube 450, thereby improving the turbocharging effect. Therefore, the grain harvester of the present invention has the advantages of good worm gear turbocharging effect and high heat exchange efficiency. Meanwhile, the pipe wall opening and the air storage chamber 460 form a resonant cavity around the pipe cavity. This resonant cavity can also achieve noise reduction and silencing during the exhaust gas / air emission process. Therefore, as an unexpected technical effect of the grain harvester of the present invention, it also has the advantage of low operating noise.

[0075] Furthermore, during operation, the first control strategy of the grain harvester of the present invention, which is set to the initial mode (or optimal working mode), will make corresponding corrections when the heat exchange efficiency of the cold medium is insufficient (i.e., the exhaust gas temperature is higher than the first temperature threshold and the cold medium temperature is lower than the second temperature threshold) and the ambient air temperature is too high (i.e., the exhaust gas temperature is lower than the first temperature threshold and the cold medium temperature is higher than the second temperature threshold). By using machine learning, the grain harvester of the present invention can better adapt to the operating conditions and operating environment. Therefore, the grain harvester of the present invention also has the advantage of high intelligence.

[0076] In some preferred embodiments of the grain harvester of the present invention, the inner liner 420 is made of elastic rubber material and the air supply pipe 430 is made of metal corrugated pipe, so as to cause both to expand and contract radially.

[0077] Elastic rubber materials are a class of polymeric materials with good elasticity and deformability. They can undergo significant deformation under external force and quickly return to their original shape after the force is removed. Their unique properties make them widely used in industrial and daily life applications requiring durability, elasticity, and compression resistance. The characteristics of elastic rubber materials are: high elasticity—elastic rubber materials can return to their original shape under significant deformation and exhibit significant elasticity; low and high temperature adaptability—some elastic rubber materials have good resistance to high and low temperatures and can work in extreme environments; corrosion resistance—many elastic rubber materials have strong oil resistance, water resistance, and chemical corrosion resistance; wear resistance—they have excellent wear resistance and are suitable for applications subject to frequent friction; sealing and isolation properties—due to their good deformability and sealing performance, elastic rubber is widely used in seals and shock absorbers. Common elastic rubber materials include natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), hydrogenated nitrile butadiene rubber (HNBR), silicone rubber (SI), nitrile butadiene rubber (NBR), thermoplastic elastomers (TPE), thermoplastic polyurethane (TPU), thermoplastic silicone rubber (TPSi), and thermoplastic elastomer polyester (TPE-E).

[0078] Metal bellows are flexible pipes made of metal with a corrugated structure, used to transport media such as liquids, gases, or solid particles, and capable of absorbing vibrations, displacements, and deformations within the system. Metal bellows are typically made of stainless steel, copper, aluminum, or other metals, possessing good corrosion resistance, pressure resistance, and high-temperature resistance, making them suitable for piping systems in various industrial fields. Their structural features include: corrugated structure—the main body of the metal bellows has a multi-corrugated structure, giving it a certain degree of flexibility and compressibility; connection method—metal bellows are usually connected to the piping system via flanges or welding to ensure sealing; deformation absorption—metal bellows can absorb deformations such as thermal expansion and contraction, vibration, and displacement generated in the piping system, protecting the system's stability and safety; corrosion resistance—manufactured using corrosion-resistant metal materials, suitable for media transmission systems in industries such as chemical, petroleum, and food; pressure resistance—metal bellows can withstand certain internal and external pressures, suitable for high-pressure piping systems; and high-temperature resistance—made of metal materials, possessing good high-temperature resistance and resistance to thermal expansion. Common materials for metal corrugated pipes include stainless steel, copper, aluminum, aluminum alloy, nickel alloy, titanium alloy, and chromium alloy.

[0079] In the above embodiment, the heat exchange tube 450 is a metal tube, and the two ends of the heat exchange tube 450 are sealed to the inner liner tube 420 by heat fusion bonding, so that the position of the heat exchange tube 450 is relatively fixed and does not shift when the inner liner tube 420 undergoes elastic deformation.

[0080] In the above embodiments, when the grain harvester of the present invention is performing a harvesting operation, after the grain harvester operates according to the first control strategy, it further includes:

[0081] S211, obtain the first gas pressure of the exhaust gas flowing through the first heat exchanger 120;

[0082] S212, after the first air pressure is higher than the first pressure threshold, reduce the speed of the refrigerant pump 340;

[0083] S213, after the first air pressure is lower than the first pressure threshold, increase the speed of the refrigerant pump 340.

[0084] During the operation of the grain harvester of the present invention described above, the first pressure threshold is also a range value, thus further improving the applicability of the grain harvester of the present invention. As a result of controlling the grain harvester of the present invention according to the above operating process, as described in S400, the rotational speed of the refrigerant pump 340 is proportional to the refrigerant pressure of the refrigerant medium. Increasing the speed of the refrigerant pump 340 increases the pressure of the refrigerant, causing the inner liner tube 420 to be compressed inward, effectively deflated. This reduces the space between the inner liner tube 420 and the air supply pipe 430, thus decreasing the capacity of the air storage chamber 460. Consequently, the differences between the inner diameter of the inner liner tube 420, the inner diameter of the air supply pipe 430, and the inner diameter of the air supply pipe 430's opening are reduced, or even eliminated. This reduces the pressure drop of the exhaust gas in the air supply pipe 430, thereby increasing the first pressure. Conversely, if the pressure drop were increased, the first pressure would decrease, preventing it from becoming excessively high. Therefore, by controlling the pressure of the refrigerant, the first pressure of the exhaust gas is influenced, ensuring it remains within the first pressure threshold range and guaranteeing the normal operation of the turbine.

[0085] As stated in S300, the opening degree of the flow valve 320 is positively correlated with the flow rate of the cold medium, which will affect the heat exchange efficiency of the cold medium in the first heat exchanger 120. That is, as the flow rate of the cold medium increases, the heat exchange efficiency of the first heat exchanger 120 will also increase accordingly.

[0086] In the above embodiments, when the grain harvester of the present invention is performing a harvesting operation, after the grain harvester operates according to the first control strategy, it may further include:

[0087] S221, obtain the second air pressure and air temperature of the air flowing out of the second heat exchanger 230;

[0088] S222, after the air temperature is lower than the third temperature threshold, increase the opening of the flow valve 320;

[0089] S223, after the air temperature is higher than the third temperature threshold and the second air pressure is higher than the second pressure threshold, increase the opening of the flow valve 320, increase the speed of the refrigerant pump 340, and continue to increase the second air pressure.

[0090] As described in section S222 above, when the air temperature is too low, increasing the opening of the flow valve 320 can increase the heat exchange efficiency of the cold medium in the refrigeration system 300, which means that the air in the second heat exchanger 230 can be heated better, thereby increasing the air temperature. However, when both the air temperature and exhaust gas pressure are already high, in order to ensure the normal operation of the engine assembly 100, as much heat as possible can be transferred to the lifting-drying device 200 to reduce the adverse effects of overheating on the engine assembly 100.

[0091] Based on this, the inner liner 420 and air supply pipe 430 of the grain harvester of the present invention, when using elastic materials / structures, allow the refrigerant pressure and refrigerant flow rate of the cold medium to be applied to the first heat exchanger 120, thereby changing the first pressure of the exhaust gas and the heat exchange efficiency of the first heat exchanger 120, thus achieving heat exchange control. This enables the grain harvester of the present invention to control complex and indirect parameters with easily detectable and controllable parameters, improving the controllability of the grain harvester of the present invention.

[0092] In some preferred embodiments of the grain harvester of the present invention, before the engine 110 and the feeding auger 220 are started, the grain harvester of the present invention can also be controlled by the following steps, which include:

[0093] S110, with the engine 110 running and the feeding auger 220 off, controls the grain harvester to operate according to a second control strategy; wherein the second control strategy includes:

[0094] S111, obtain the exhaust gas temperature;

[0095] S112, after the exhaust gas temperature is higher than the fourth temperature threshold, the refrigerant pump 340 is controlled to run at the first set speed, and the opening degree of the flow valve 320 is the first set opening degree; wherein, the fourth temperature threshold is lower than the first temperature threshold.

[0096] S113, when the exhaust gas temperature is equal to or lower than the fourth temperature threshold, shut off the refrigerant pump 340.

[0097] In the above embodiment, the refrigeration system 300 operates before the feeding auger 220 to preheat the feeding pipe 210, further improving the drying effect on the grain during the feeding process. Simultaneously, the refrigeration system 300 only operates when the exhaust gas temperature is sufficient, avoiding the problem of excessive energy consumption caused by low heat exchange efficiency.

[0098] In some further preferred embodiments of the grain harvester of the present invention, after modifying the first control strategy, the grain harvester of the present invention can also be controlled by the following steps, which include:

[0099] S510, after the grain harvester operates according to the modified first control strategy, determines whether the refrigerant temperature is below the second temperature threshold when the exhaust gas temperature is above the first temperature threshold.

[0100] If it is lower than that, then reduce the first temperature threshold and the fourth temperature threshold;

[0101] If equal to or higher than, the existing first and fourth temperature thresholds are maintained.

[0102] In the above embodiment, under the operation of the modified first control strategy, in order to avoid the problem of low exhaust gas pressure caused by blockage of the first heat exchanger 120, or in order to alleviate the impact of increased air resistance in the air supply pipe 430 of the first heat exchanger 120 caused by long-term use, the first temperature threshold and the fourth temperature threshold are lowered to obtain an earlier opportunity to adjust the opening of the flow valve 320 and the speed of the refrigerant pump 340, thereby avoiding damage to the engine assembly 100 and the refrigeration system 300 caused by late adjustment.

[0103] In some preferred embodiments of the grain harvester of the present invention, such as Figure 4 and Figure 6 As shown, the outer casing 410 is a sleeve-shaped tube with necked ends; and the air supply pipe 430 has a central cavity 431 that communicates with the two ends of the outer casing 410 with the same diameter, and an annular groove cavity 432 formed in the folds; wherein, the annular groove cavity 432 has a constricted portion 433 located between the groove opening and the belly, and its axial width gradually increases from the constricted portion 433 to both sides, and the radial distance between the constricted portion 433 and the groove opening is smaller than the distance between the constricted portion 433 and the belly.

[0104] In the above embodiments, when the grain harvester of the present invention is in operation and the air storage chamber 460 is filled with exhaust gas / compressed air, the exhaust gas / compressed air in the air storage chamber 460 will pressurize the constriction portion 433 of the annular cavity, causing the constriction portion 433 to close, thereby achieving the purpose of maintaining pressure, so as to replenish air when the air pressure in the central cavity 431 decreases. In particular, the lower the air pressure in the air storage chamber 460, the larger the opening of the constriction portion 433 will be, thereby achieving better air replenishment.

[0105] In some preferred embodiments of the grain harvesting process of the present invention, the heat exchange tube 450 passes through the air supply tube 430 through an opening in the tube wall, and a spiral groove extending along the length of the tube is formed on the outer wall of the heat exchange tube 450, with the two ends of the spiral groove located on opposite sides of the air storage chamber 460. This spiral groove guides the exhaust gas / air from the central cavity 431 into the air storage chamber 460 more effectively, allowing more exhaust gas / air to enter the air storage chamber 460 before entering the annular cavity, further improving the "air-locking" effect and also better achieving the resonance noise reduction effect.

[0106] In some preferred embodiments of the grain harvesting method of the present invention, the inner liner tube 420 extends vertically, and there are multiple heat exchange tubes 450, which extend horizontally and are spaced apart vertically. Furthermore, axial partitions 470 extending vertically are formed on the left and right sides of the refrigerant cavity 440, so that the refrigerant cavity 440 is divided into a left sub-cavity connected to the left end of each heat exchange tube 450 and a right sub-cavity connected to the right end of each heat exchange tube 450. A left circumferential partition 481 is formed in the left sub-cavity, which is vertically spaced between two connected heat exchange tubes 450, and a right circumferential partition 482 is formed in the right sub-cavity, which is vertically spaced between two connected heat exchange tubes 450. The left circumferential partition 481 and the right circumferential partition 482 are staggered vertically and there is a heat exchange tube 450 between them, so that the multiple heat exchange tubes 450 and the refrigerant cavity 440 are divided into a loop-shaped flow channel. Meanwhile, the refrigerant inlet 491 and refrigerant outlet 492, which are respectively provided on opposite sides and at opposite ends of the outer shell 410, enable the refrigerant to flow in a multi-pass "serpentine" manner in the heat exchanger, further increasing the heat exchange efficiency between the refrigerant and the exhaust gas / air.

[0107] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A grain harvester, characterized in that, include: An engine assembly comprising an engine, a first heat exchanger, and a turbocharger connected in sequence, the first heat exchanger being connected between the exhaust outlet of the engine and the turbine chamber inlet of the turbocharger to cause exhaust gas exiting from the exhaust outlet to heat a coolant flowing through the first heat exchanger. A lifting-drying device includes a feeding pipe for conveying grains, a feeding auger extending along the length of the pipe inside the feeding pipe, and a second heat exchanger connected to the feeding pipe for blowing air along the feeding direction. The second heat exchanger is configured to guide air heated by the cold medium into the feeding pipe. A refrigeration system, the refrigeration system including a refrigerant container for storing the refrigerant, and a refrigerant pump for pumping the refrigerant to circulate sequentially between a flow valve, an intercooler, a first heat exchanger, a second heat exchanger and the refrigerant container; as well as, Both the first heat exchanger and the second heat exchanger include an outer shell, an inner liner tube, and a gas supply tube that are sequentially fitted together from the outside to the inside. A refrigerant cavity for flowing through a refrigerant medium is defined between the outer shell and the inner liner tube. A heat exchange tube that passes through the gas supply tube and communicates with the refrigerant cavity is connected to the inner liner tube. A gas storage cavity that communicates with the cavity of the gas supply tube through an opening in the tube wall is defined between the inner liner tube and the gas supply tube.

2. The grain harvester according to claim 1, characterized in that, The inner liner is made of elastic rubber material, and the air supply pipe is made of corrugated metal material, so that both can expand and contract radially.

3. The grain harvester according to claim 2, characterized in that, The outer shell is a sleeve-shaped structure with both ends tapering; and... The air supply pipe has a central cavity that is of equal diameter to the two ends of the outer shell, and an annular groove cavity formed in the folds; wherein the annular groove cavity has a constricted portion located between the groove opening and the belly, and its axial width gradually increases from the constricted portion to both sides, and in the radial direction, the distance from the constricted portion to the groove opening is less than the distance from the constricted portion to the belly.

4. The grain harvester according to claim 1, characterized in that, The heat exchange tube passes through the gas supply pipe through the opening in the tube wall, and a spiral groove extending along the length of the tube is formed on the outer tube wall of the heat exchange tube, with the two ends of the spiral groove located on opposite sides of the gas storage chamber.

5. The grain harvester according to claim 1, characterized in that, The inner liner tube extends vertically, and there are multiple heat exchange tubes, each extending horizontally and spaced apart vertically; furthermore... Axial partitions extending vertically are formed on both the left and right sides of the refrigerant cavity to divide the refrigerant cavity into a left sub-cavity connected to the left end of each heat exchange tube and a right sub-cavity connected to the right end of each heat exchange tube. A left circumferential partition, vertically spaced between two connected heat exchange tubes, is formed in the left sub-cavity, and a right circumferential partition, vertically spaced between two connected heat exchange tubes, is formed in the right sub-cavity. The left and right circumferential partitions are staggered vertically and have one heat exchange tube between them, so that the multiple heat exchange tubes and the refrigerant cavity are divided into a loop-shaped flow channel.

6. A control method applicable to a grain harvester as described in any one of claims 1 to 5, characterized in that, include: The temperature of the exhaust gas flowing through the first heat exchanger in the grain harvester, the flow rate and pressure of the cooling medium, and the temperature of the cooling medium flowing through the second heat exchanger in the grain harvester are obtained. In response to the start command received sequentially or simultaneously by the engine and the feeding auger in the grain harvester, the grain harvester is controlled to operate according to a first control strategy; wherein in the first control strategy, the refrigerant pump in the grain harvester operates at a first set speed, and the flow valve in the grain harvester opens at a first set opening degree; When the grain harvester is operating according to the first control strategy, the exhaust gas temperature is higher than the first temperature threshold, and the refrigerant temperature is lower than the second temperature threshold, the opening of the flow valve is increased to increase the refrigerant flow; and the first control strategy is modified by increasing the first set opening. When the grain harvester is operating according to the first control strategy, the exhaust gas temperature is lower than the first temperature threshold, and the refrigerant temperature is higher than the second temperature threshold, the speed of the refrigerant pump is increased to increase the refrigerant pressure; and the first control strategy is modified by increasing the first set speed. After the first control strategy is corrected, the next time the engine and the feeding auger are started, they will operate according to the corrected first control strategy.

7. The control method according to claim 6, characterized in that, When the control method is used in a grain harvester as described in claim 2, after the grain harvester operates according to the first control strategy, it further includes: Obtain the first gas pressure of the exhaust gas flowing through the first heat exchanger; After the first air pressure exceeds the first pressure threshold, the speed of the refrigerant pump is reduced; After the first gas pressure falls below the first pressure threshold, the speed of the refrigerant pump is increased.

8. The control method according to claim 6, characterized in that, When the control method is used in a grain harvester as described in claim 2, after the grain harvester operates according to the first control strategy, it further includes: Obtain the second air pressure and air temperature of the air flowing out of the second heat exchanger; After the air temperature falls below the third temperature threshold, the opening of the flow valve is increased; After the air temperature is higher than the third temperature threshold and the second air pressure is higher than the second pressure threshold, the opening of the flow valve is increased, the speed of the refrigerant pump is increased, and the second air pressure continues to increase.

9. The control method according to claim 6, characterized in that, Before the engine and the feeding auger are started, the following are also included: With the engine running and the feeding auger off, the grain harvester is controlled to operate according to a second control strategy; wherein the second control strategy includes: Obtain the exhaust gas temperature; After the exhaust gas temperature exceeds the fourth temperature threshold, the refrigerant pump is controlled to operate at the first set speed, and the opening degree of the flow valve is the first set opening degree; wherein, the fourth temperature threshold is lower than the first temperature threshold. If the exhaust gas temperature is equal to or lower than the fourth temperature threshold, the refrigerant pump is shut down.

10. The control method according to claim 9, characterized in that, After modifying the first control strategy, the following is also included: After the grain harvester operates according to the modified first control strategy, it is determined whether the refrigerant temperature is lower than the second temperature threshold when the exhaust gas temperature is higher than the first temperature threshold. If the temperature is below the threshold, then the first temperature threshold and the fourth temperature threshold are reduced.

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