A passion fruit storage simulation experimental device and experimental method thereof

Abstract

The invention discloses a passion fruit storage simulation experiment device and an experiment method thereof, comprising a fresh-keeping box, a temperature sensor, an environment heating device and a heating and cooling device, wherein the temperature sensor is installed in the fresh-keeping box, the environment heating device is installed outside the fresh-keeping box, a layered partition for placing passion fruit is arranged in the fresh-keeping box, an infrared pair of tubes for detecting the placement of passion fruit is installed on the side wall of the fresh-keeping box between adjacent layered partitions, and a heating and cooling device is installed on the top of the fresh-keeping box. The invention can realize gradient heating and cooling to store passion fruit, and through gradient heating and cooling, the temperature of the storage room is prevented from dropping or rising suddenly, and the water vapor in the storage room is reduced from condensing into water droplets on the surface of the fruit, effectively preventing the growth and reproduction of microorganisms, and preventing the fruit skin from being rotten and deteriorated as a whole due to contamination, thereby achieving a better storage effect.

Description

Technical Field

[0001] The invention belongs to the technical field of passion fruit storage and relates to a passion fruit storage simulation experimental device and an experimental method thereof. Background Art

[0002] At present, passion fruit storage methods at home and abroad can be roughly divided into two types: natural cooling storage and artificial cooling storage.

[0003] Natural cooling storage is a simple, traditional and economical storage method. Ventilated cellar is a commonly used natural cooling storage method. It is a storage method that uses the low temperature of the external natural environment to adjust the temperature and humidity of the storage environment. Although its use is subject to regional and seasonal restrictions, and the storage temperature cannot be controlled at the expected temperature. However, this storage method is still widely used in my country.

[0004] Artificial cooling storage is a storage method that uses mechanical refrigeration to adjust the temperature of the passion fruit storage environment. This storage method is not restricted by region and season, and can more accurately control the storage temperature, thus extending the storage time of passion fruit. So far, countries with advanced economic and technological development in the world have regarded artificial cooling storage as a necessary means of storing fresh fruits and vegetables.

[0005] On the basis of mechanical refrigeration storage, refrigerated controlled atmosphere storage has been developed. This storage method is based on the storage characteristics of fruits, and the gas composition in the storage room is artificially controlled, such as reducing the oxygen content and increasing the carbon dioxide content, so as to provide a suitable storage environment for passion fruit. This controlled atmosphere storage method has a very good storage effect for passion fruit, a fruit with active respiration. However, in terms of current technological development, the economic cost of controlled atmosphere storage is relatively high, and the operating experience and management experience are highly complex. At present, spontaneous controlled atmosphere storage is widely used in my country, that is, using the respiration of passion fruit itself to absorb and consume the oxygen in the storage room, thereby releasing carbon dioxide to achieve the controlled atmosphere effect. Although this storage technology is not as good as the real controlled atmosphere storage technology, it is easy to operate, has a lower economic cost, and has less risk.

[0006] All of the above methods can not satisfy the preservation of passion fruit.

[0007] In addition, the temperature measurement in the passion fruit cold storage room is generally a single point temperature measurement, which cannot fully reflect the main temperature distribution of the entire cold storage space, and this single temperature measurement point often cannot be placed in the center of the space, so the temperature of the center of the space cannot be obtained. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a passion fruit storage simulation experimental device and an experimental method thereof to solve the problems existing in the prior art.

[0009] The technical scheme adopted by the present invention is: a passion fruit storage simulation experimental device, including a fresh-keeping box, a temperature sensor, an environmental heating device and a heating and cooling device, the temperature sensor is installed in the fresh-keeping box, the environmental heating device is installed outside the fresh-keeping box, a layered partition for placing passion fruit is arranged in the fresh-keeping box, infrared tubes for detecting the placement of passion fruit are installed on the side walls of the fresh-keeping box between adjacent layered partitions, and a heating and cooling device is installed on the top of the fresh-keeping box.

[0010] Preferably, the infrared tube module, temperature sensor, environment heating device and heating and cooling device are connected to a main controller, and the main controller is connected to a display module.

[0011] Preferably, the above-mentioned environmental heating device includes a square cavity, an exhaust fan and a heating cavity. The four sides and the inner side of the top of the square cavity are equidistant from the fresh-keeping box. The side wall of the square cavity is a hollow structure. Air holes are provided on the inner plate of the side wall. The exhaust fan is connected to the heating cavity through an air inlet duct. The exhaust fan is respectively connected to the top side and the center of the four sides of the square cavity through multiple branched air outlet ducts and is connected to the inner cavity of the square cavity. The heating and cooling cavity is arranged outside the heating device.

[0012] Preferably, the above-mentioned heating and refrigeration device includes a heating and refrigeration cavity equipped with a semiconductor refrigeration module and an exhaust fan, and a fresh-keeping box. The fresh-keeping box is a hollow structure. The heating and refrigeration cavity is connected to the top and the four side wall cavities of the fresh-keeping box through a branched air intake pipe, and an exhaust fan is installed on the air intake pipe. Cold air holes are arranged on the inner walls of the four sides of the fresh-keeping box, and the heating and refrigeration cavity is arranged outside the heating device.

[0013] Preferably, six temperature sensors are used, which are respectively arranged at the lower right corner of the left inner wall of the fresh-keeping box, the upper left corner of the left inner wall, the lower right corner of the right inner wall, the upper left corner of the right inner wall, the center of the inner bottom of the first storage shelf formed by the partition, and the center of the inner bottom of the second storage shelf formed by the partition.

[0014] An experimental method for a passion fruit storage simulation experimental device, the method comprising: setting a fresh-keeping temperature value or a passion fruit out-of-warehouse temperature value, measuring the temperature values ​​of six temperature sensors, detecting whether there is passion fruit cargo on a partition through an infrared pairing tube module, calculating a spatially distributed temperature average value P according to a weight formula, wherein the unit of P is ° C, and after calculation, temperature control is performed by adopting a gradient heating and cooling method according to the spatially distributed temperature average value P.

[0015] Preferably, the calculation method of the above-mentioned spatial distribution temperature average value P is: the temperature values ​​of the temperature values ​​measured by the six temperature sensors are respectively X 1 , X 2 , X 3 , X 4 , X 5 , X 6, let Y be the temperature value measured by the temperature sensor arranged on the passion fruit shelf after multiplying the weight, the unit of P is ℃, and Y 0 is the temperature value measured by the temperature sensor on the non-passion fruit shelf in the space after multiplying the weight by the sensor, the unit of P is ℃, T is the temperature compensation operator, the unit of P is ℃, then:

[0016]

[0017]

[0018]

[0019] The calculation formula for the spatial distribution temperature average value P is:

[0020] P=Y 0 +Y+T (4)

[0021]

[0022] In the formula, P is the average value of the spatial distribution temperature calculated according to the designed weight formula;

[0023] A i is the weight coefficient;

[0024] A j is the weight coefficient;

[0025] B j is the weight coefficient;

[0026] n is the number of temperature sensors installed on the non-shelf tiered partitions in the fresh-keeping box;

[0027] m is the total number of temperature sensors;

[0028] j = n + 1;

[0029] X i The temperature measured by the corresponding temperature sensor is P, and the unit is °C;

[0030] X j The temperature measured by the jth temperature sensor, P is in °C;

[0031] x j is the allowable value of the weight coefficient, which can be 0 or 1. When the output pin level of a certain infrared pair tube is detected to be 0, that is, there is passion fruit cargo, then x j Set to 1, the corresponding weight coefficient A j It works, weight B j Not effective; when the output pin level of a certain infrared pair tube is detected to be 1, that is, there is no passion fruit product, that is, there is no passion fruit product, then xj Set to 0, the corresponding weight coefficient B j It works;

[0032] If P is greater than the upper limit or less than the lower limit, an alarm will be issued.

[0033] The gradient heating and cooling method is: Start the heating and exiting method: when the temperature is lower than the set value, the temperature is increased, and the temperature gradient is 5-7 degrees Celsius each time. When heating, a period of time is passed to determine whether the weighted average of the six temperature values ​​reaches the temperature gradient value plus the initial value. If it reaches it, the temperature is maintained at a constant value for a certain period of time and then heated again; if it does not reach it, the temperature continues to increase with an increasing gradient until the rising temperature reaches the set value, then the temperature is stopped; the cooling storage method is the same as the heating and exiting method, but in the opposite direction.

[0034] Beneficial effects of the present invention: Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] (1) The passion fruit storage simulation experiment device of the present invention can realize the accurate temperature rise and fall simulation of passion fruit, follow the ambient temperature simulation, adjust the internal temperature change, realize the optimal temperature storage of passion fruit, the storage effect is better, and the simulation experiment data is accurate;

[0036] (2) The present invention can achieve gradient heating and cooling to store passion fruit, as well as gradient heating out of the warehouse, effectively preventing condensation of water droplets on the surface of the fruit during summer transportation, and shortening the storage time of the fruit. It can also better reflect the temperature in the storage room through multi-point temperature distribution measurement and weight calculation, which is conducive to control. By gradient heating and cooling, it can avoid sudden drop or rise in the storage room temperature, reduce the condensation of water vapor in the storage room into water droplets on the surface of the fruit, effectively prevent the growth and reproduction of microorganisms, and avoid the fruit skin from being rotten and deteriorated as a whole due to contamination, thereby achieving a better storage effect and a longer storage period. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the present invention;

[0038] Figure 2 It is a schematic diagram of the control structure of the present invention;

[0039] Figure 3 Schematic diagram of temperature sensor layout;

[0040] Figure 4 It is the PID control flow chart;

[0041] Figure 5 Main controller circuit diagram;

[0042] Figure 6 is the clock circuit diagram;

[0043] Figure 7This is the reset circuit diagram;

[0044] Figure 8 Automatically download the circuit diagram of the power module and USB module;

[0045] Fig. 9 This is the temperature sensor circuit diagram;

[0046] Fig.10 This is the circuit diagram of the LCD display module;

[0047] Fig.11 This is the CHQB circuit connection diagram;

[0048] Fig.12 This is the circuit connection diagram of the heating and cooling drive module. DETAILED DESCRIPTION

[0049] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0050] Example 1: Figure 1-Figure 12 As shown, a passion fruit storage simulation experimental device comprises a fresh-keeping box 1, a temperature sensor 2, an environmental heating device 3 and a heating and cooling device 6. The temperature sensor 2 is installed in the fresh-keeping box 1, and the environmental heating device 3 is installed outside the fresh-keeping box 1. A layered partition 4 for placing passion fruit is arranged in the fresh-keeping box 1. An infrared pair tube 5 for detecting the placement of passion fruit is installed on the side wall of the fresh-keeping box 1 between adjacent layered partitions 4. A heating and cooling device 6 is installed on the top of the fresh-keeping box 1. Figure 1 As shown, the fresh-keeping box 1 is divided into four compartments, namely compartment ①, compartment ②, compartment ③ and compartment ④, and compartment ①, compartment ②, compartment ③ and compartment ④ are located at the upper left position, the upper right position, the lower left position and the lower right position respectively.

[0051] Preferably, the infrared tube module 5, the temperature sensor 2, the environment heating device 3 and the heating and cooling device 6 are connected to a main controller, and the main controller is connected to a display module.

[0052] The main controller is AT89C52, which is one of the earliest microprocessors to be mass-produced and used. It has 4K bytes of flash memory (FLASH), 21 special function registers SFR, on-chip RAM (128 bytes of on-chip data memory), 32 I / O lines, two 16-bit timers / counters (each with four working modes), 5 interrupt structures, etc. In addition, it is also an 8-bit microprocessor with a low operating voltage and a CMOS interface with high computing performance. It is generally called a 51 single-chip microcomputer. Figure 5 shown.

[0053] The clock / reset circuit connected to the controller: The external clock uses two external 22pF capacitors and an external 12M crystal oscillator to generate a standard clock pulse signal, and then connects this circuit to the XTAL1 and XTAL2 terminals to form an external clock source. The two capacitors are mainly used to fine-tune the frequency. The reset circuit uses a key reset circuit, which consists of a reset button, a 10uF inter-electrode capacitor, and a 10kΩ resistor. The specific circuit diagram is as follows Figure 6-7 shown.

[0054] The power module and USB automatic download module connected to the main controller: The power module of the control circuit is designed with two power supply modes. One is powered by an external power supply (+5V DC), and the other is powered by the +5V voltage provided by the USB interface. In this experiment, for the sake of convenience and economy, no external +5V power supply is provided. The +5V voltage is directly extracted from the USB interface, and after simple voltage stabilization and filtering, it is directly powered to the system control circuit. Since the heating and cooling circuit of the system has a large power consumption, the power supply is directly powered by a 12V / 6A power adapter. The USB automatic download module uses the CH340 chip. The data is transmitted to the CH340 chip through the USB through the download software. The CH340 erases the program in the AT89C52 through the automatic reset circuit, and then writes the transmitted data to the microcontroller to complete the automatic download function. The power module and USB automatic download module circuit are as follows Figure 8 As shown:

[0055] Temperature sensor selection: The temperature sensor uses DS18B20 to detect the temperature of the storage room. DS18B20 is an improved digital intelligent temperature sensor. The detected temperature data is discrete data (i.e. digital signal), which can be directly transmitted to the main controller. Data communication can be performed without other processing, and its data transmission only occupies one I / O port. Compared with the AD conversion temperature measurement circuit, it not only occupies less I / O, but also reduces the computing load of the single-chip microcomputer, making the single-chip microcomputer work more stably; in addition, its high accuracy is enough to meet the accuracy requirements of the temperature rise and fall system, and the economic cost is also very low. DS18B20 circuit wiring diagram, such as Fig. 9 shown.

[0056] The display module uses LCD1602 as the display. LCD1602 can display two lines of characters, a total of 32 characters. In this temperature control system, the display data includes temperature gradient and real-time temperature value, which is stress-free for LCD1602. In addition, LCD1602 has simple programming control, friendly display interface, low power consumption, small size, and mature technology application. Therefore, it is selected as the display module of this system, and the connection method uses direct control (that is, the data pin and the control pin are directly connected to the microcontroller I / O port). The LCD1602 circuit connection diagram is as follows Fig.10 shown.

[0057] The infrared tube module is composed of a nose bridge CHQB infrared receiver and a matching remote control. CHQB has a conventional nose bridge appearance, a smooth and beautiful appearance, and has the characteristics of good infrared penetration and high receiving sensitivity. The infrared receiver uses the German ATA series chip lamination process packaging, which makes the chip more compatible, faster and more stable. In addition, the use of lamination packaging can more effectively control external light and electrical influences. The CHQB circuit connection diagram is as follows Fig.11 shown.

[0058] In fact, the semiconductor cooling plate can achieve the effect of a heating plate by reversing the phase line, so that the hot side becomes the cold side and the cold side becomes the hot side. However, it has extremely strict requirements on heat dissipation, and there is a risk of burning if you are not careful. Therefore, the heating and cooling device uses independent heating modules and cooling modules. The heating plate model in the heating module is selected as XH-RE4040-15V50W semiconductor ceramic heating plate, and the cooling semiconductor plate in the cooling module is selected as TEC1-12706 semiconductor cooling plate. The heating and cooling drive module focuses on control and the design time is limited. Therefore, the heating and cooling drive module selects a mature DC motor drive module. Among them, the heating plate and the cooling plate use a high-power H-bridge / dual-channel drive module to control the power supply, while the cooling fan and the air supply fan use the L298N drive module to control the power supply. The specific drive circuit is as follows Fig.12 shown.

[0059] Preferably, the above-mentioned environmental heating device 3 includes a square cavity 7, an exhaust fan 8 and a heating cavity 9. The four sides and the inner side of the top of the square cavity 7 are equidistant from the fresh-keeping box 1. The side wall of the square cavity 7 is a hollow structure. Air holes 10 are arranged on the inner plate of the side wall. The exhaust fan 8 is connected to the heating cavity 9 through an air inlet pipe. The exhaust fan 8 is connected to the top side and the center of the four sides of the square cavity 7 through multiple branched air outlet pipes and is connected to the inner cavity of the square cavity. The heating and cooling cavity 11 is arranged outside the heating device 3. The heating cavity 9 is provided with an air inlet. A heating wire or a semiconductor heating plate is installed in the heating cavity 9. Heat is evenly delivered into the interior of the square cavity through the hollow structure of the square cavity to simulate the heating of the fresh-keeping box. The temperature is heated evenly and the simulation is more accurate.

[0060] Preferably, the heating and cooling device 6 includes a heating and cooling chamber 11 equipped with a semiconductor refrigeration module and an exhaust fan 12. The fresh-keeping box 1 is a hollow structure. The heating and cooling chamber 11 is connected to the top and the four side wall cavity of the fresh-keeping box 1 through a branched air intake pipe. The exhaust fan 12 is installed on the air intake pipe. Cold air holes 13 are provided on the four inner walls of the fresh-keeping box 1. The heating and cooling chamber 11 is arranged outside the heating device 3. The heating and cooling chamber 11 is provided with an air inlet. Semiconductor ceramic heating plates and semiconductor refrigeration plates are installed in the heating and cooling chamber 11, which can realize heating or cooling. The fresh-keeping box with a hollow structure is used for balanced air intake, and the heating and cooling are more uniform, avoiding uneven temperature control caused by local excessively high or low temperatures.

[0061] Preferably, the temperature sensors 2 are 6 in number, which are arranged at the lower right corner of the left inner wall, the upper left corner of the left inner wall, the lower right corner of the right inner wall, the upper left corner of the right inner wall, the center of the inner bottom of the storage shelf 1 (grid ①) formed by the partition, and the center of the inner bottom of the storage shelf 2 (grid ②) formed by the partition, respectively. Figure 3 The layout of this position can better reflect the temperature balance measurement and avoid the temperature being difficult to control due to excessively high or low temperature.

[0062] Embodiment 2: An experimental method of a passion fruit storage simulation experimental device, the method comprising: setting a preservation temperature value or a passion fruit exit temperature value, measuring the temperature values ​​of six temperature sensors, detecting whether there is passion fruit cargo on the partition through an infrared pairing module, calculating the spatial distribution temperature average value P according to a weight formula, wherein the unit of P is ° C, and after calculation, temperature control is performed using a gradient heating and cooling method according to the spatial distribution temperature average value P.

[0063] Preferably, the calculation method of the above-mentioned spatial distribution temperature average value P is: the temperature values ​​of the temperature values ​​measured by the six temperature sensors are respectively X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , let Y be the temperature value measured by the temperature sensor arranged on the passion fruit shelf after multiplying the weight, the unit of P is ℃, and Y 0 is the temperature value measured by the temperature sensor on the non-passion fruit shelf in the space after multiplying the weight by the sensor, the unit of P is ℃, T is the temperature compensation operator, the unit of P is ℃, then:

[0064]

[0065]

[0066]

[0067] The temperature weight calculation formula is:

[0068] P=Y 0 +Y+T (4)

[0069]

[0070] In the formula, A i is the weight coefficient; Figure 1 After testing the simulation experimental device shown, the weight coefficients A1-A4 are 1 / 10; A5 is 2 / 10; A6 is 4 / 10 which is better;

[0071] P is the average spatial distribution temperature calculated according to the designed weight formula;

[0072] A i is the first weight coefficient. Figure 1 After testing the simulation experimental device shown, the weight coefficient A1-A4 is preferably 1 / 10;

[0073] A j is the second weight coefficient. Figure 1 After testing the simulation experimental device shown, the weight coefficient A5 is 2 / 10; A6 is 4 / 10 which is better;

[0074] B j is the third weight coefficient. Figure 1 After testing the simulation experimental device shown in the figure, B j 1 / 10 is better;

[0075] n is the number of temperature sensors installed on the non-shelf tiered partitions in the fresh-keeping box, which is 4 here;

[0076] m is the total number of temperature sensors, which is 6 here;

[0077] j = n + 1;

[0078] X i The unit of P is °C, which is the temperature measured by the corresponding temperature sensor.

[0079] X j The unit of P is °C, which is the temperature measured by the corresponding temperature sensor.

[0080] x j is the allowable value of the weight coefficient, which can be 0 or 1. When the output pin level of a certain infrared pair tube is detected to be 0, that is, there is passion fruit cargo, then x j Set to 1, the corresponding weight coefficient A j It works, weight B j Not effective; when the output pin level of a certain infrared pair tube is detected to be 1, that is, there is no passion fruit, then x jSet to 0, the corresponding weight coefficient B j It works;

[0081] If P is greater than the upper limit or less than the lower limit, an alarm will be issued.

[0082] The gradient heating and cooling method is as follows: Start the heating and unloading method: When the temperature is lower than the set value, the temperature is raised, and the temperature rise gradient is 5-7 degrees Celsius each time. When heating, it is determined at intervals whether the weighted average of the six temperature values ​​reaches the temperature rise gradient value plus the initial value. If it reaches it, it is kept at a constant temperature value for a certain period of time and then heated again; if it does not reach it, it continues to heat up. The temperature is raised in an incremental gradient until the rising temperature reaches the set value, then the temperature is stopped. After the temperature is raised by controlling the temperature, the passion fruit is unloaded and transferred to the truck to avoid condensation caused by excessively high external temperature (large temperature difference) when it is taken out, thereby affecting the shelf life of the passion fruit; the cooling storage method is the same as the heating and unloading method, but in the opposite direction. The gradient heating and cooling method of this method can accurately control the preservation and delivery of passion fruit and avoid frosting on the skin. The gradient heating and cooling method adopts improved PID control, which is convenient for accurately realizing the temperature change of staged gradient control. Because the actuator (heating and cooling equipment) of the simulation experimental device is an object PID without an integral component, the position PID is selected, that is, the deviation between the actual position and the expected position of the current system is used for PID control, such as Figure 4 As shown, the first step of the software processing flow is system initialization, which includes infrared initialization, timer initialization, LCD initialization, 18B20 initialization and PID initialization, and LCD fixed data display; the second step is PID parameter setting, timer real-time temperature display, temperature * 100 conversion; the third step is waiting to receive infrared signals, receiving the infrared signal sent by the remote control, giving the heating and cooling gradient according to the received decoding key value, and performing gradient heating or cooling until the set temperature is reached. If it is cooling, after reaching the set temperature, the system continues to perform constant temperature 6℃ PID control to provide storage conditions for passion fruit.

[0083] The continuous expression of PID control is as follows:

[0084]

[0085] Where: Kp is the proportionality coefficient; e(t) is the error; T i is the integration period; T d is the differential period.

[0086] Since computers process digital signals, continuous signals need to be discretized. The discrete expression is as follows:

[0087]

[0088] It is generally written in the following form:

[0089]

[0090] in: is the integration coefficient; is the differential coefficient.

[0091] The code is as follows:

[0092]

[0093]

[0094] Gradient cooling, constant temperature 6℃ PID control and temperature stability judgment function

[0095]

[0096] The present invention can achieve gradient temperature rise and fall for storing passion fruit, as well as gradient temperature rise and fall for unloading, effectively preventing water droplets from condensing on the surface of the fruit during summer transportation, and shortening the fruit storage time. The invention can better reflect the temperature in the storage room through multi-point temperature distribution measurement and weight calculation, which is conducive to control. By gradient temperature rise and fall, the temperature in the storage room can be prevented from dropping or rising suddenly, and the condensation of water vapor in the storage room into water droplets on the surface of the fruit can be reduced, effectively preventing the growth and reproduction of microorganisms, and preventing the fruit skin from being rotten and deteriorated as a whole due to contamination, thereby achieving a better storage effect and a longer storage period.

[0097] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An experimental method for a passion fruit storage simulation experimental device, characterized in that: The passion fruit storage simulation experimental device comprises a fresh-keeping box (1), a temperature sensor (2), an environmental heating device (3) and a heating and cooling device (6); the temperature sensor (2) is installed in the fresh-keeping box (1); the environmental heating device (3) is installed outside the fresh-keeping box (1); a layered partition (4) for placing passion fruit is arranged in the fresh-keeping box (1); an infrared pair of tube modules (5) for detecting the placement of passion fruit are installed on the side walls of the fresh-keeping box (1) between adjacent layered partitions (4); and the heating and cooling device (6) is installed on the top of the fresh-keeping box (1); Six temperature sensors (2) are used and are arranged respectively at the lower right corner of the left inner wall surface, the upper left corner of the left inner wall surface, the lower right corner of the right inner wall surface, the upper left corner of the right inner wall surface, the center of the inner bottom of the first storage shelf formed by the partition, and the center of the inner bottom of the second storage shelf formed by the partition of the fresh-keeping box (1); The experimental method comprises: setting a fresh-keeping temperature value or a temperature value for passion fruit to be discharged from a warehouse, measuring the temperature values ​​of six temperature sensors, detecting whether there is passion fruit cargo on the partition by using an infrared pairing tube module (5), calculating a spatially distributed temperature average value P according to a weight formula, wherein the unit of P is ° C, and after calculation, using a gradient heating and cooling method to control the temperature according to the spatially distributed temperature average value P; The calculation method of the spatial distribution temperature average value P is as follows: the temperature values ​​of the 6 temperature sensors are X1, X2, X3, X4, X5, and X6 respectively. Let Y be the temperature value measured by the temperature sensor arranged on the passion fruit shelf after multiplying the weight, in °C, Y0 be the temperature value measured by the temperature sensor on the non-passion fruit shelf in the space after multiplying the weight, in °C, T is the temperature compensation operator, in °C, then The calculation formula for the spatial distribution temperature average value P is: P=Y0+Y+T (4) In the formula, P is the average value of the spatial distribution temperature calculated according to the designed weight formula; A i is the weight coefficient; A j is the weight coefficient; B j is the weight coefficient; n is the number of temperature sensors installed on the non-shelf tiered partitions in the fresh-keeping box; m is the total number of temperature sensors; j = n + 1; X i The temperature measured by the corresponding temperature sensor is in °C; X j The temperature measured by the jth temperature sensor is in °C; x j is the allowable value of the weight coefficient, which can be 0 or 1. When the output pin level of a certain infrared pair tube is detected to be 0, that is, there is passion fruit cargo, then x j Set to 1, the corresponding weight coefficient A j It works, weight B j Not effective; when the output pin level of a certain infrared pair tube is detected to be 1, then x j Set to 0, the corresponding weight coefficient B j It works; If P is greater than the upper limit or less than the lower limit, an alarm will be issued.

2. The experimental method of a passion fruit storage simulation experimental device according to claim 1, characterized in that: The infrared tube module (5), the temperature sensor (2), the environment heating device (3) and the heating and cooling device (6) are connected to a main controller, and the main controller is connected to a display module.

3. The experimental method of a passion fruit storage simulation experimental device according to claim 1, characterized in that: The environmental heating device (3) comprises a square cavity (7), an air suction fan (8) and a heating cavity (9); the four sides and the inner side of the top of the square cavity (7) are equidistant from the fresh-keeping box (1); the side wall of the square cavity (7) is a hollow structure; an air vent (10) is provided on the inner plate of the side wall; the air suction fan (8) is connected to the heating cavity (9) through an air inlet duct; the air suction fan (8) is connected to the top side and the center of the four sides of the square cavity (7) through a plurality of branched air outlet ducts and is connected to the inner cavity of the square cavity (7); a heating element is installed in the heating cavity (9).

4. The experimental method of a passion fruit storage simulation experimental device according to claim 1, characterized in that: The heating and cooling device (6) comprises a heating and cooling chamber (11) equipped with a semiconductor cooling module and an exhaust fan (12); the fresh-keeping box (1) is a hollow structure; the heating and cooling chamber (11) is connected to the top and four side wall cavities of the fresh-keeping box (1) through a branched air intake duct; the exhaust fan (12) is installed on the air intake duct; cold air holes (13) are arranged on the four inner walls of the fresh-keeping box (1); and the heating and cooling chamber (11) is arranged outside the environmental heating device (3).

5. The experimental method of a passion fruit storage simulation experimental device according to claim 1, characterized in that: The gradient heating and cooling method is: Start the heating and exiting method: when the temperature is lower than the set value, the temperature is increased, and the temperature gradient is 5-7 degrees Celsius each time. When heating, a period of time is passed to determine whether the weighted average of the six temperature values ​​reaches the temperature gradient value plus the initial value. If it reaches it, the temperature is maintained at a constant value for a certain period of time and then heated again; if it does not reach it, the temperature continues to increase with an increasing gradient until the rising temperature reaches the set value, then the temperature is stopped; the cooling storage method is the same as the heating and exiting method, and the temperature changes in the opposite direction.

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