Grain harvester and control method thereof

Abstract

The invention provides a grain harvester and a control method thereof, and belongs to the technical field of grain drying. According to the grain harvesting machine, the heat exchange pipe directly penetrates through the air supply pipe, so that tail gas / air flowing through the air supply pipe directly exchanges heat with a refrigerant medium in the heat exchange pipe, the length of a heat transfer path is reduced, heat loss is reduced, and the heat exchange efficiency is improved; meanwhile, in order to compensate for pressure drop caused by the fact that the heat exchange pipe penetrates through the air supply pipe, the pipe cavity of the air supply pipe is communicated with the air storage cavity through the pipe wall opening of the air supply pipe, so that the air storage cavity stores air when the air pressure of tail gas / air is large, air is supplemented into the pipe cavity when the air pressure is small, and then the air pressure in the pipe cavity is relatively stable. And the pressure drop caused by the heat exchange tube is compensated, so that the turbocharging effect is improved. Therefore, the grain harvester has the advantages of being good in turbocharging effect and high in heat exchange efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of grain drying, and in particular to a grain harvester and a control method thereof. Background Art

[0002] Prior research results (ZL2023103579960-Heat exchanger, combine harvester exhaust heat recovery device and combine harvester) proposed a heat exchanger suitable for grain harvesters, which can recover the engine waste heat in the turbocharger to promote the use of this part of the engine waste heat in grain drying and reduce energy consumption. In this heat exchanger, the cold medium (such as heat exchange water) flows between the two layers of bellows, and the engine exhaust flows in the expandable inner cylinder in the inner layer of the bellows, and the heat pipe connected between the inner layer of the bellows and the inner cylinder is used as a heat conduction medium. In this heat exchanger, the inner cylinder is squeezed and shrunk by the spring, making the channel in the inner cylinder for circulating the engine exhaust gas narrower, and forcing the engine exhaust gas to be decompressed, resulting in a decrease in the exhaust gas flow rate flowing from the engine into the turbine chamber and a slower flow rate, thereby making the turbocharging effect worse; at the same time, the refrigerant medium needs to exchange heat with the engine exhaust gas through a heat pipe. Not only is the heat transfer route long, but the heat loss is also large, resulting in the need for multiple heat exchangers to compensate, thereby 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 a control method thereof that overcomes the above problems or at least partially solves the above problems, and can solve the problem that the existing heat exchange system causes poor turbocharging effect and low heat exchange efficiency.

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

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

[0006] A lifting and drying device, the lifting and drying device comprising a feeding pipe for conveying grains, a feeding auger extending along the length of the pipe is arranged in the feeding pipe, a second heat exchanger for blowing along the feeding direction is connected to the feeding pipe, and the second heat exchanger is configured to guide the air heated by the refrigerant 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 to circulate sequentially among a flow valve, an intercooler, the first heat exchanger, the second heat exchanger and the refrigerant container; and,

[0008] The first heat exchanger and the second heat exchanger both include an outer shell, an inner liner tube and an air supply pipe which are sequentially sleeved from the outside to the inside, a refrigerant cavity for the refrigerant to flow through is defined between the outer shell and the inner liner tube, a heat exchange tube passing through the air supply pipe and communicating with the refrigerant cavity is connected to the inner liner tube, and an air storage cavity connected to the air supply pipe cavity through an opening in the pipe wall of the air supply pipe is defined between the inner liner tube and the air supply pipe.

[0009] Preferably, the inner liner pipe is made of elastic rubber material, and the air supply pipe is made of a metal bellows, so as to facilitate the expansion and contraction deformation of both in the radial direction.

[0010] Preferably, the shell is in the shape of a sleeve with necks at both ends; and,

[0011] The lumen of the air supply pipe has a central cavity portion that is equidiametrically connected to the two ports of the shell, and an annular groove cavity portion formed in the folds; wherein the annular groove cavity portion has a necking portion located between the notch and the belly, and its axial width gradually increases from the necking portion to both sides, and the radial distance between the necking portion and the notch is smaller than the distance between the necking portion and the belly.

[0012] Preferably, the heat exchange tube passes through the air supply tube from the tube wall opening, and a spiral groove extending along the tube length direction is formed on the outer tube wall of the heat exchange tube, and both ends of the spiral groove are respectively located on opposite sides of the air storage cavity.

[0013] Preferably, the inner lining tube extends up and down, there are multiple heat exchange tubes, and the multiple heat exchange tubes extend left and right and are spaced apart in the up and down directions; and,

[0014] An axial partition extending up and down is formed on the left and right sides of the refrigerant cavity respectively, so that the refrigerant cavity is divided 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 is formed in the left sub-cavity and is located between two connected heat exchange tubes, and a right circumferential partition is formed in the right sub-cavity and is located between two connected heat exchange tubes, and the left circumferential partition and the right circumferential partition are staggered in the vertical direction, and there is a heat exchange tube between the two, so that multiple heat exchange tubes and the refrigerant cavity are divided into a return flow channel.

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

[0016] Obtaining the exhaust gas temperature of the exhaust gas flowing through the first heat exchanger in the grain harvester, the refrigerant flow rate and the refrigerant pressure of the refrigerant medium, and the refrigerant temperature of the refrigerant medium flowing through the second heat exchanger in the grain harvester;

[0017] In response to the engine and the feeding auger in the grain harvester receiving the start command successively or synchronously, 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 is opened at a first set opening;

[0018] When the grain harvester operates according to the first control strategy, the exhaust gas temperature is higher than a first temperature threshold, and the refrigerant temperature is lower than a 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 operates 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 are operated according to the corrected first control strategy.

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

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

[0023] After the first air pressure is higher than a first pressure threshold, reducing the speed of the refrigerant pump;

[0024] After the first air pressure is lower than the first pressure threshold, the rotation speed of the refrigerant pump is increased.

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

[0026] Acquire a second air pressure and air temperature of the air after flowing out of the second heat exchanger;

[0027] After the air temperature is lower than a third temperature threshold, increasing the opening of the flow valve;

[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 rotation 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 method further comprises:

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

[0031] obtaining the exhaust gas temperature;

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

[0033] When the exhaust gas temperature is equal to or lower than the fourth temperature threshold, the refrigerant pump is turned off.

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

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

[0036] If so, the first temperature threshold and the fourth temperature threshold are reduced.

[0037] The beneficial effects of the present invention are:

[0038] In the grain harvester of the present invention, the heat exchange tube passes directly through the air supply tube, so that the exhaust gas / air flowing through the air supply tube directly exchanges heat with the refrigerant medium in the heat exchange tube, 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 tube passing through the air supply tube, the tube wall of the air supply tube is opened so that the tube cavity of the air supply tube is connected to the air storage cavity, so that the air storage cavity stores air when the air pressure of the exhaust gas / air is relatively high, and replenishes air into the tube cavity when the air pressure is relatively low, thereby making the air pressure in the tube cavity relatively stable, and compensating for the pressure drop caused by the heat exchange tube, so that the turbocharging effect is improved. Therefore, the grain harvester of the present invention has the advantages of good worm gear supercharging effect and high heat exchange efficiency.

[0039] In addition, the tube wall opening and the air storage cavity form a resonance cavity around the tube cavity, which can also achieve the effect of noise reduction and silencing during the exhaust gas / air discharge 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, so that the constricted portion is closed, thereby achieving the purpose of maintaining pressure, so as to prepare for air replenishment when the air pressure in the central cavity decreases, especially 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 supercharging effect and high heat exchange efficiency.

[0041] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

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

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

[0045] Figure 3 yes Figure 2 The main view of the heat exchanger;

[0046] Figure 4 yes Figure 3 AA section view of the middle heat exchanger;

[0047] Figure 5 yes Figure 3 BB section view of the middle heat exchanger;

[0048] Figure 6 yes Figure 4 A partial enlarged view of the heat exchanger C.

[0049] in:

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

[0051] Material lifting and drying device-200, material feeding pipe-210, material 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, shell 410, liner tube 420, air delivery tube 430, central cavity 431, annular groove cavity 432, constricted portion 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 DESCRIPTION

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

[0055] Unless otherwise clearly defined and limited, the terms "set", "install", "connect", "connect", "fix", "couple" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. A person skilled in the art should be able to understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0056] In addition, in the description of this embodiment, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. That is, in the description of this embodiment, the first feature being "above", "above", and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below", or "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0057] In the description of the present embodiment, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0058] like Figure 1 The schematic diagram of the flow direction of the airflow and the cooling medium of the grain harvester of the present invention is shown in FIG. Figure 2-5The structural schematic diagram of the heat exchanger in the grain harvester of the present invention is shown. In the 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, and the first heat exchanger 120 is connected between the exhaust gas outlet of the engine 110 and the inlet of the turbine chamber 131 of the turbocharger 130 to promote the exhaust gas discharged from the exhaust gas outlet to heat the refrigerant flowing through the first heat exchanger 120. The lifting-drying device 200 includes a feeding pipe 210 for conveying grains, and a feeding auger 220 extending in the length direction of the pipe is arranged in the feeding pipe 210. The feeding pipe 210 is also connected to a second heat exchanger 230 for blowing air in the feeding direction, and the second heat exchanger 230 is configured to guide the air heated by the refrigerant into the feeding pipe 210. The refrigeration system 300 includes a refrigerant container 310 for storing a refrigerant, and a refrigerant pump 340 for pumping the refrigerant to circulate sequentially between 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 use the same heat exchanger structure 400, which includes an outer shell 410, an inner liner 420 and an air supply pipe 430 that are sequentially sleeved from the outside to the inside, a refrigerant cavity 440 for the refrigerant to flow through is defined between the outer shell 410 and the inner liner 420, a heat exchange tube 450 that passes through the air supply pipe 430 and communicates with the refrigerant cavity 440 is connected to the inner liner 420, and an air storage cavity 460 that is connected to the air supply pipe 430 through the pipe wall opening of the air supply pipe 430 is defined between the inner liner 420 and the air supply pipe 430.

[0059] In the above embodiment, the air inlet of the turbocharger 130 is connected to the air inlet of the intercooler 330 so that the gas from the turbocharger 130 exchanges heat with the refrigerant medium of the intercooler 330. Turbocharging is a technology that uses the exhaust gas generated by the operation of the engine 110 to drive air compression. The turbocharger 130 uses the exhaust gas discharged by the engine 110 as power to drive the turbine (located in the exhaust duct) in the turbine chamber 131, and the turbine drives the coaxial impeller (located in the intake duct). The impeller compresses the fresh air sent from the intake duct and then sends it into the piston cylinder of the engine 110. When the speed of the engine 110 is accelerated, the exhaust gas discharge speed and the turbine speed are also accelerated synchronously, the air compression degree is increased, the intake volume of the engine 110 is increased accordingly, and the output power of the engine 110 can be increased. However, if the high-temperature air after supercharging is directly allowed to enter the engine 110, the engine 110 will be knocked due to the high air temperature, and even damage and flameout will occur. The intercooler 330 plays the role of cooling the air. The high-temperature air is cooled by the intercooler 330 and then enters the engine 110. The turbocharger 130 compresses the air so that the gas at normal temperature and pressure becomes a high-temperature and high-pressure gas, and the intercooler 330 plays the role of cooling the high-temperature gas, and can also use the heat of the gas after turbocharging. For example, in some embodiments of the grain harvester of the present invention, the intercooler 330 is a water-cooled intercooler 330. The water-cooled intercooler 330 uses circulating cooling water as a refrigerant medium to cool the air flowing through it. The advantages of the water-cooled intercooler 330 are high cooling efficiency and flexible installation position, without the need to use a long connecting pipe.

[0060] In the above embodiment, the lifting-drying device 200 has a wind drying function compared to the traditional lifting device. Among them, the traditional lifting device mainly includes a lifting device, a conveying pipe or belt, a fan system, a collection bin and an adjustment device. The lifting device is the core part of the lifting device, which is usually composed of rotating blades or propellers (such as the feeding auger 220 selected in the grain harvester of the present invention). It generates airflow or mechanical force through rotation to throw the grains upward or to a designated position. The design of the lifting device needs to ensure that it can reduce damage to the grains while efficiently transmitting. The materials generated by the lifting device are transported to the collection bin or transport vehicle through a conveying pipe or belt. The belt is usually made of wear-resistant material to ensure that it can withstand a large amount of grains during the harvesting process and keep working for a long time. Some lifting devices are also equipped with a fan system, which uses wind power to blow the grains from the lifting device to the conveyor belt or collection bin. This fan system is usually used to enhance the fluidity of materials and reduce the compaction or accumulation of grains. The harvester's bunker is a container for storing the grain that is winnowed up, usually connected to a hoisting device. As the hoist and conveyor system deliver grain to the bunker, the capacity of the bunker gradually increases until it is full or needs to be unloaded. The hoisting device is usually equipped with some adjustable devices for adjusting 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 losses. When in use, the grain enters the bunker after harvesting: after the grain is threshed and cleaned, the grain is fed into the bunker by mechanical vibration or screening devices. The bunker lifts the grain: the bunker usually consists of rotating blades or other mechanical devices, which lift the grain to a set height through rotation or pushing action. Transport to the collection area: the lifted grain is transported to the bunker or directly to the transport vehicle through belts, pipes or wind systems. Grain collection and storage: the bunker or transport vehicle receives the grain and prepares it for transportation or subsequent processing. Different from the traditional lifting device, in the embodiment of the grain harvester of the present invention, a plurality of axially spaced air outlets are provided on the feed pipe 210, and the air outlet of the second heat exchanger 230 is connected to these air outlets, so as to promote the air or compressed air flowing through the second heat exchanger 230 for heat exchange to be blown into the feed pipe 210 from the air outlet to dry the grain in the feed pipe 210.

[0061] In the above embodiment, the refrigerant container 310 in the refrigeration system 300 has the function of storing the refrigerant and also has the function of dissipating the heat of the refrigerant. Especially after the refrigerant flows out from the second heat exchanger 230, if there is still a high temperature, the refrigerant container 310 will be more critical. Refrigerant is a medium used to transfer heat in a refrigeration cycle system. Refrigerant has specific physical and chemical properties and can change its state (liquid and gaseous) under low and high temperature conditions, thereby absorbing and releasing heat. Common refrigerants include Freon series, ammonia, alkanes, carbon dioxide, etc. The main functions of the refrigerant in the refrigeration system 300 include: absorbing heat - the refrigerant absorbs heat in the evaporator, reducing the temperature of the surrounding air or water, transferring heat - the refrigerant transfers the absorbed heat to the condenser through the compressor and then releases it to the external environment, and regulating pressure and temperature - the refrigerant can adjust the pressure and temperature between the evaporator and the condenser under the action of the throttle valve or expansion valve to achieve a refrigeration cycle. When selecting a refrigerant, its physical properties (such as boiling point, freezing point, heat capacity, etc.), chemical properties (ozone depletion potential, global warming potential, etc.), safety and environmental protection need to be considered. In recent years, with the improvement of environmental awareness, some traditional refrigerants have been eliminated and gradually turned to low-temperature and environmentally friendly alternatives. Common refrigerants and their characteristics include:

[0062] 1. Freon series (R-22, R-410A, etc.): Commonly used in household air conditioning and commercial air conditioning systems, with good refrigeration effect and heat transfer performance, but with high potential for ozone layer depletion.

[0063] 2. Ammonia (NH3): used in some industrial and commercial refrigeration systems 300, has high refrigeration performance, but is toxic to humans.

[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 gradually being used in some energy-efficient refrigeration systems300.

[0066] Selecting a suitable refrigerant is an important consideration in the design and operation of the refrigeration system 300, which is not only related to the refrigeration effect and energy efficiency, but also to environmental protection and safety.

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

[0068] S100, obtaining the exhaust gas temperature of the exhaust gas flowing through the first heat exchanger 120 in the grain harvester, the refrigerant flow rate and the 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 engine 110 and the feeding auger 220 in the grain harvester receiving the start command successively or synchronously, controlling the grain harvester 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 opens at a first set opening;

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

[0071] S400, when the grain harvester operates 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, increasing the speed of the refrigerant pump 340 to increase the refrigerant pressure; and, by increasing the first set speed, modifying the first control strategy;

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

[0073] Among them, the first temperature threshold and the second temperature threshold are both range values, so that the exhaust gas temperature and the refrigerant temperature can fluctuate within the range value, expanding the environmental conditions under which the grain harvester of the present invention can operate normally, and improving the applicability of the grain harvester of the present invention.

[0074] Based on this, in the above embodiment, the grain harvester of the present invention uses the heat exchange tube 450 to directly pass through the air supply pipe 430, so that the exhaust gas / air flowing through the air supply pipe 430 directly exchanges heat with the refrigerant medium in the heat exchange tube 450, 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 tube 450 passing through the air supply pipe 430, the tube wall of the air supply pipe 430 is opened, so that the tube cavity of the air supply pipe 430 is connected to the air storage cavity 460, so that the air storage cavity 460 stores air when the air pressure of the exhaust gas / air is relatively high, and replenishes air into the tube cavity when the air pressure is relatively low, thereby making the air pressure in the tube cavity relatively stable, and also compensating for the pressure drop caused by the heat exchange tube 450, so that the turbocharging effect is improved. Therefore, the grain harvester of the present invention has the advantages of good worm gear supercharging effect and high heat exchange efficiency. At the same time, the tube wall opening and the air storage chamber 460 form a resonance chamber around the tube cavity, which can also achieve the effect of noise reduction and silencing during the exhaust gas / air discharge 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] In addition, during the operation of the grain harvester of the present invention, the first control strategy is set to the initial mode (or optimal working mode). When the heat exchange efficiency of the refrigerant medium is insufficient (i.e., the exhaust gas temperature is higher than the first temperature threshold, and the refrigerant 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 refrigerant temperature is higher than the second temperature threshold), the first control strategy will be modified accordingly. By means of 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 a high degree of intelligence.

[0076] In some preferred embodiments of the grain harvester of the present invention, the inner lining tube 420 uses an elastic rubber material, and the air supply pipe 430 uses a metal bellows to promote the expansion and contraction deformation of the two in the radial direction.

[0077] Among them, elastic rubber materials (Elastomeric Rubber Materials) are a type of polymer materials with good elasticity and deformability. They can undergo large deformations when subjected to external forces and can quickly return to their original shape after the external forces are removed. Their unique characteristics make them widely used in industrial and living fields that require durability, elasticity and compression resistance. The characteristics of elastic rubber materials are: high elasticity - elastic rubber materials can return to their original shape under large deformations and have obvious elasticity, low and high temperature adaptability - some elastic rubber materials have good high and low temperature resistance and can work in extreme environments, corrosion resistance - many elastic rubber materials have strong oil resistance, water resistance, and chemical corrosion resistance, wear resistance - excellent wear resistance, suitable for occasions that are often subject to friction, sealing and isolation - due to its good deformation ability 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 rubber (HNBR), silicone rubber (SI), nitrile rubber (NBR), thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), thermoplastic silicone rubber (TPSi), and thermoplastic elastomer polyester (TPE-E).

[0078] Among them, metal bellows is a flexible pipe made of metal material with a corrugated structure, which is used to transmit liquid, gas or solid particles and other media, and can absorb vibration, displacement and deformation in the system. Metal bellows are usually made of metal materials such as stainless steel, copper, aluminum, etc., with good corrosion resistance, pressure resistance and high temperature resistance, suitable for pipeline systems in various industrial fields. Its structural characteristics are: corrugated structure-the main part of the metal bellows is a multiple corrugated structure, which makes it flexible and compressible, connection method-metal bellows are usually connected to the pipeline system by flanges or welding to ensure sealing, deformation absorption-metal bellows can absorb deformation such as thermal expansion and contraction, vibration, displacement, etc. generated in the pipeline system, and protect the stability and safety of the system, corrosion resistance-made of corrosion-resistant metal materials, suitable for medium transmission systems in chemical, petroleum, food and other industries, pressure resistance-metal bellows can withstand certain internal and external pressures, suitable for high-pressure pipeline systems, high temperature resistance-made of metal materials, with good high temperature resistance and resistance to thermal expansion. Common metal bellows are made of stainless steel, copper, aluminum, aluminum alloy, nickel alloy, titanium alloy, chromium alloy, etc.

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

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

[0081] S211, obtaining a 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, reducing the speed of the refrigerant pump 340;

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

[0084] In the operation process of the grain harvester of the present invention, the first pressure threshold is also a range value, thereby further improving the applicability of the grain harvester of the present invention. As an effect of controlling the grain harvester of the present invention according to the above operation process, as described in step S400, the rotation speed of the refrigerant pump 340 is proportional to the refrigerant pressure of the refrigerant medium. After the speed of the refrigerant pump 340 is increased, the pressure of the refrigerant medium will increase accordingly, so as to cause the inner liner tube 420 to be compressed inward, that is, the inner liner tube 420 will become deflated, thereby reducing the interlayer space between the inner liner tube 420 and the air supply pipe 430, and thus reducing the capacity of the air storage chamber 460, thereby reducing or even eliminating the difference between the inner diameter of the abdomen of the inner liner tube 420, the inner diameter of the abdomen of the air supply pipe 430, and the inner diameter of the tube mouth of the air supply pipe 430, thereby reducing the pressure drop of the exhaust gas in the air supply pipe 430, and thereby increasing the first air pressure; otherwise, the pressure drop of the exhaust gas in the air supply pipe 430 will increase, thereby reducing the first air pressure, and avoiding the first air pressure being too high. Therefore, the first air pressure of the exhaust gas is affected by the size of the pressure of the refrigerant medium, so as to cause the first air pressure of the exhaust gas to be maintained within the range of the first pressure threshold, thereby ensuring the normal operation of the turbine.

[0085] Of course, as described in S300, the opening of the flow valve 320 is positively correlated with the flow rate of the refrigerant medium, which will affect the heat exchange efficiency of the refrigerant medium in the first heat exchanger 120, that is, as the refrigerant flow rate in the refrigerant medium increases, the heat exchange efficiency of the first heat exchanger 120 will also increase accordingly.

[0086] In the above embodiment, 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, obtaining a second air pressure and air temperature of the air after flowing out of the second heat exchanger 230;

[0088] S222, after the air temperature is lower than the third temperature threshold, increasing 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, the opening of the flow valve 320 is increased, the rotation speed of the refrigerant pump 340 is increased, and the second air pressure continues to increase.

[0090] As described in S222 above, when the air temperature is too low, the heat exchange efficiency of the refrigerant in the refrigeration system 300 can be increased by increasing the opening of the flow valve 320, so that the air in the second heat exchanger 230 can be better heated, thereby increasing the air temperature; and when 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 only be transferred to the lifting and drying device 200 to reduce the adverse effects of overheating on the engine assembly 100.

[0091] Based on this, the inner lining pipe 420 and the air supply pipe 430 of the grain harvester of the present invention, when using elastic materials / structures, enable the refrigerant pressure and refrigerant flow of the refrigerant medium to act on the first heat exchanger 120, so as to change the first pressure of the exhaust gas and the heat exchange efficiency of the first heat exchanger 120, thereby realizing the control of the heat exchange, and further enabling the grain harvester of the present invention to control complex and indirect parameters with parameters that are easy to detect and control, thereby 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, when the engine 110 is in a running state and the feeding auger 220 is in a closed state, controlling the grain harvester to operate according to a second control strategy; wherein the second control strategy includes:

[0094] S111, obtaining exhaust gas temperature;

[0095] S112, after the exhaust gas temperature is higher than the fourth temperature threshold, controlling the refrigerant pump 340 to operate at the first set speed, and the opening of the flow valve 320 is the first set opening; 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, turning off the refrigerant pump 340.

[0097] In the above embodiment, the refrigeration system 300 will be operated before the feeding auger 220 to preheat the feeding pipe 210, further improving the drying effect of the grains during the feeding process. At the same time, the refrigeration system 300 will only work when the exhaust gas temperature is sufficient, avoiding the problem of excessive energy consumption of the refrigeration system 300 caused by too low heat exchange efficiency.

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

[0099] S510, after the grain harvester operates according to the modified first control strategy, determining whether the refrigerant temperature is lower than the second temperature threshold when the exhaust gas temperature is higher than the first temperature threshold,

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

[0101] If it is equal to or higher than the above, the existing first temperature threshold and the fourth temperature threshold are maintained.

[0102] In the above embodiment, when the corrected first control strategy is running, in order to avoid the problem of too low exhaust pressure caused by blockage of the first heat exchanger 120, or in other words, to alleviate the effect of increased air resistance in the air supply pipe 430 in 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 too late adjustment.

[0103] In some preferred embodiments of the grain harvester of the present invention, Figure 4 and Figure 6 As shown, the shell 410 is in the shape of a sleeve with necks at both ends; and the tube cavity of the air supply pipe 430 has a central cavity portion 431 that is equidiametrically connected to the two ends of the shell 410, and an annular groove cavity portion 432 formed in the folds; wherein the annular groove cavity portion 432 has a necked portion 433 located between the notch and the belly, and its axial width gradually increases from the necked portion 433 to both sides, and the radial distance between the necked portion 433 and the notch is smaller than the distance between the necked portion 433 and the belly.

[0104] In the above embodiment, 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 apply pressure to the necking portion 433 of the annular cavity portion, so that the necking portion 433 is closed, thereby achieving the purpose of maintaining pressure, so as to prepare for air replenishment when the air pressure in the central cavity portion 431 decreases. In particular, the lower the air pressure in the air storage chamber 460, the larger the opening of the necking portion 433 will be, thereby achieving better air replenishment.

[0105] In some preferred embodiments of the grain harvesting of the present invention, the heat exchange tube 450 passes through the air supply tube 430 from the opening of the tube wall, and a spiral groove extending along the tube length direction is formed on the outer tube wall of the heat exchange tube 450, and the two ends of the spiral groove are respectively located on opposite sides of the air storage cavity 460. The spiral groove guides the exhaust gas / air of the central cavity 431 to enter the air storage cavity 460 better, so that the exhaust gas / air enters the air storage cavity 460 more before entering the annular cavity, further improving the "air locking" effect, and also better achieving the effect of resonance silencing.

[0106] In some preferred embodiments of grain harvesting of the present invention, the lining tube 420 extends up and down, there are multiple heat exchange tubes 450, and the multiple heat exchange tubes 450 all extend left and right and are spaced apart in the vertical direction; and, axial partitions 470 extending up and down are respectively formed on the left and right sides of the refrigerant cavity 440 to cause the refrigerant cavity 440 to be partitioned 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 and is located between two connected heat exchange tubes 450, and a right circumferential partition 482 is formed in the right sub-cavity and is located between two connected heat exchange tubes 450, and the left circumferential partition 481 and the right circumferential partition 482 are staggered in the vertical direction, and there is a heat exchange tube 450 between the two, so as to cause the multiple heat exchange tubes 450 and the refrigerant cavity 440 to be partitioned into a circular flow channel. At the same time, combined with the refrigerant inlet 491 and the refrigerant outlet 492 respectively arranged on the opposite sides and opposite ends of the shell 410, the refrigerant medium can perform a multi-circuit "snake-like" flow in the heat exchanger, further increasing the heat exchange efficiency between the refrigerant medium and the exhaust gas / air.

[0107] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

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

2. The grain harvester according to claim 1, characterized in that The inner lining tube is made of elastic rubber material, and the air supply tube is made of a metal bellows, so as to promote the expansion and contraction deformation of the two in the radial direction.

3. The grain harvester according to claim 2, characterized in that: The shell is in the shape of a sleeve with necks at both ends; and The lumen of the air supply pipe has a central cavity portion that is equidiametrically connected to the two ports of the shell, and an annular groove cavity portion formed in the folds; wherein the annular groove cavity portion has a necking portion located between the notch and the belly, and its axial width gradually increases from the necking portion to both sides, and in the radial direction, the distance from the necking portion to the notch is smaller than the distance from the necking portion to the belly.

4. The grain harvester according to claim 1, characterized in that: The heat exchange tube passes through the air supply tube from the tube wall opening, and a spiral groove extending along the tube length direction is formed on the outer tube wall of the heat exchange tube, and two ends of the spiral groove are respectively located on opposite sides of the air storage cavity.

5. The grain harvester according to claim 1, characterized in that: The inner lining tube extends up and down, and there are multiple heat exchange tubes, and the multiple heat exchange tubes extend left and right and are spaced apart in the up and down directions; and An axial partition extending up and down is formed on the left and right sides of the refrigerant cavity respectively, so that the refrigerant cavity is divided 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 is formed in the left sub-cavity and is located between two connected heat exchange tubes, and a right circumferential partition is formed in the right sub-cavity and is located between two connected heat exchange tubes, and the left circumferential partition and the right circumferential partition are staggered in the vertical direction, and there is a heat exchange tube between the two, so that multiple heat exchange tubes and the refrigerant cavity are divided into a return flow channel.

6. A control method suitable for a grain harvester as claimed in any one of claims 1 to 5, characterized in that: include: Obtaining the exhaust gas temperature of the exhaust gas flowing through the first heat exchanger in the grain harvester, the refrigerant flow rate and the refrigerant pressure of the refrigerant medium, and the refrigerant temperature of the refrigerant medium flowing through the second heat exchanger in the grain harvester; In response to the engine and the feeding auger in the grain harvester receiving the start command successively or synchronously, 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 is opened at a first set opening; When the grain harvester operates according to the first control strategy, the exhaust gas temperature is higher than a first temperature threshold, and the refrigerant temperature is lower than a 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 operates 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 are operated according to the corrected first control strategy.

7. The control method according to claim 6, characterized in that: In the case where the control method is used in the grain harvester as described in claim 2 above, after the grain harvester operates according to the first control strategy, it also includes: obtaining a first gas pressure of the exhaust gas flowing through the first heat exchanger; After the first air pressure is higher than a first pressure threshold, reducing the speed of the refrigerant pump; After the first air pressure is lower than the first pressure threshold, the rotation speed of the refrigerant pump is increased.

8. The control method according to claim 6, characterized in that: In the case where the control method is used in the grain harvester as described in claim 2 above, after the grain harvester operates according to the first control strategy, it also includes: Acquire a second air pressure and air temperature of the air after flowing out of the second heat exchanger; After the air temperature is lower than a third temperature threshold, increasing the opening of the flow valve; 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 rotation 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 method further comprises: When the engine is in a running state and the feeding auger is in a closed state, the grain harvester is controlled to operate according to a second control strategy; wherein the second control strategy includes: obtaining the exhaust gas temperature; After the exhaust gas temperature is higher than a fourth temperature threshold, controlling the refrigerant pump to operate at the first set speed, and the opening of the flow valve is the first set opening; wherein the fourth temperature threshold is lower than the first temperature threshold; When the exhaust gas temperature is equal to or lower than the fourth temperature threshold, the refrigerant pump is turned off.

10. The control method according to claim 9, characterized in that: After modifying the first control strategy, the method further includes: After the grain harvester operates according to the modified first control strategy, determining whether the refrigerant temperature is lower than a second temperature threshold when the exhaust gas temperature is higher than the first temperature threshold, If so, the first temperature threshold and the fourth temperature threshold are reduced.

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