Hot gas defrosting, refrigerating and dehumidifying integrated control system

Abstract

The invention provides a hot air defrosting, refrigerating and dehumidifying integrated control system. The hot air defrosting, refrigerating and dehumidifying integrated control system comprises two independent refrigerating, dehumidifying and defrosting units, an intelligent control system and an auxiliary device. The two sets of refrigerating, dehumidifying and defrosting units can realize wheel running, independent running or simultaneous starting and stopping, and during wheel running, when one set of unit breaks down, the other set of unit is automatically switched to run; each set of refrigeration, dehumidification and defrosting unit comprises a compressor, a condensation fan, an evaporation fan, a liquid supply valve, a refrigeration valve, a dehumidification valve, a defrosting valve, a drainage heating part and a pipeline assembly; according to the invention, multi-mode automatic operation and seamless switching are realized, and the continuity of temperature and humidity control in a complex environment is guaranteed. The double-unit redundancy design significantly improves the reliability of the system, and avoids the interruption of the production process. And intelligent control logic accurately judges the defrosting requirement, the invalid defrosting frequency is reduced, and the heat exchange efficiency is improved. The frequency conversion adjusting technology optimizes the energy consumption ratio in different modes, and the overall operation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and in particular to a hot gas defrosting, refrigeration and dehumidification integrated control system. Background Art

[0002] Existing refrigeration, dehumidification, and defrosting equipment suffers from numerous technical limitations in practical applications, making it difficult to meet the demands for precise temperature and humidity control and stable system operation in complex environments. Traditional equipment typically utilizes a single-function design, with independent cooling, dehumidification, and defrosting functions. This results in low system integration and an inability to automatically switch modes based on environmental changes. Evaporator frosting is particularly problematic in low-temperature conditions. Existing defrosting mechanisms often rely on a shutdown method, which not only interrupts normal operation but also lacks precise defrost determination criteria, leading to incomplete or excessive defrosting. Regarding equipment reliability, stand-alone operation presents significant drawbacks. Failure of a core component forces the entire system to shut down, severely impacting the continuity of temperature and humidity control. The control system's lack of intelligent control makes it difficult to coordinate multi-parameter adjustments. For example, the dynamic matching of fan speed and refrigerant flow in dehumidification mode has long been an unresolved issue. Furthermore, traditional systems exhibit significant shortcomings in optimizing energy consumption. The defrost process relies excessively on electric heating, failing to fully utilize system waste heat and resulting in energy waste. These problems are more pronounced in application scenarios such as electronic manufacturing and pharmaceutical warehousing, which require high precision in temperature and humidity control.

[0003] Therefore, a hot gas defrosting, refrigeration and dehumidification integrated control system is proposed. Summary of the Invention

[0004] In view of this, the embodiments of the present invention hope to provide a hot gas defrosting, refrigeration and dehumidification integrated control system to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0005] In order to solve the above technical problems, a technical solution adopted by this application is to provide a hot gas defrosting, refrigeration and dehumidification integrated control system, including:

[0006] Two independent refrigeration, dehumidification and defrosting units, intelligent control systems and auxiliary devices;

[0007] The two sets of refrigeration, dehumidification and defrosting units can realize rotation operation, independent operation or simultaneous start and stop. When rotating operation is carried out, if one of the units fails, the other unit will automatically switch to operation;

[0008] Each set of the refrigeration, dehumidification and defrosting unit includes a compressor, a condensing fan, an evaporating fan, a liquid supply valve, a refrigeration valve, a dehumidification valve, a defrost valve, a drainage heating component and a pipeline assembly;

[0009] The intelligent control system comprises a PLC controller, a sensor group, a frequency converter and a man-machine interaction device; the sensor group comprises a temperature and humidity sensor, a pressure sensor, an evaporator temperature sensor and a defrosting termination sensor; the frequency converter is connected with the evaporative fan and is used for adjusting the rotating speed of the evaporative fan;

[0010] The intelligent control system can control the refrigeration, dehumidification and defrosting unit to run in the refrigeration mode, the dehumidification mode, the defrosting mode, the drainage mode and the strong cooling mode and realize automatic switching between the modes.

[0011] As further preferred in the technical solution, the wheel operation specifically comprises: first starting a set of refrigeration, dehumidification and defrosting unit, timing the running time of the compressor in the refrigeration and dehumidification state, and switching to the operation of another unit when the timing exceeds the set time; and manually switching the units, automatically switching to another unit when a set of units alarms.

[0012] As further preferred in the technical solution, the running process of the refrigeration mode is: starting after 5 seconds of delay when the temperature value collected by the temperature and humidity sensor is greater than the set upper limit of temperature; the liquid supply valve and the refrigeration valve are powered on, and the compressor and the evaporative fan are powered on after 3 seconds; the condensing fan is started when the pipeline pressure is greater than the set pressure of the single high-pressure pressure controller, and the condensing fan is stopped when the pipeline pressure is less than the difference between the set pressure of the single high-pressure pressure controller and the pressure bandwidth; stopping the machine after 5 seconds of delay when the temperature value is less than the set lower limit of temperature, the liquid supply valve is powered off first, and the compressor, the condensing fan, the evaporative fan and the refrigeration valve are powered off after the fluorine collection is completed.

[0013] As further preferred in the technical solution, the running process of the dehumidification mode is: starting when the humidity value collected by the temperature and humidity sensor is greater than the set upper limit of humidity and the temperature value is between the set upper and lower limits of temperature; the liquid supply valve and the dehumidification valve are powered on, and the compressor and the evaporative fan are powered on after 3 seconds; the condensing fan is started and stopped according to the pipeline pressure according to the logic in claim 3; stopping after 5 seconds of delay when the humidity value is less than the set lower limit of humidity and the temperature value is between the set upper and lower limits of temperature, and the liquid supply valve, the dehumidification valve, the compressor, the condensing fan and the evaporative fan are all powered off.

[0014] As further preferred in the technical solution, the running process of the defrosting mode is: based on the temperature value detected by the evaporator temperature sensor, timing the defrosting cycle of the compressor running time in the refrigeration or dehumidification mode, and starting when the timing reaches the set defrosting cycle time; the compressor keeps running and the evaporative fan stops; the refrigeration valve or the dehumidification valve is powered off after 3 seconds of delay, the defrosting valve is powered on, and the water pan heating pipe is powered on; the condensing fan is started and stopped according to the pipeline pressure according to the logic in claim 3; when the defrosting timing is greater than the set defrosting time or the temperature detected by the defrosting termination sensor is greater than the set stop temperature, the defrosting is terminated, the defrosting valve and the compressor are powered off, and the drainage mode is entered.

[0015] As the further preferred technical solution, the operation process of the drainage mode is that only the water pan heating pipe and the drainage pipeline heating wire are powered on, and the rest of the components are powered off; the strong cooling mode is operated after the drainage mode ends, the liquid supply valve and the refrigeration valve are powered on, the compressor is powered on after 3 seconds, the condenser fan is started and stopped according to the pipeline pressure according to the logic in claim 3, and the evaporator fan is not operated.

[0016] As the further preferred technical solution, the intelligent control system further comprises a remote communication module connected with the PLC controller, for real-time transmission of system operation data and sending of alarm messages.

[0017] As the further preferred technical solution, the pressure sensor in the sensor group comprises a high-pressure pressure sensor and a low-pressure pressure sensor for detecting the exhaust pressure and the suction pressure of the system pipeline; the defrosting termination sensor is an F2000 temperature controller, and the evaporator temperature sensor is a PT100 sensor.

[0018] As the further preferred technical solution, a phase loss / phase sequence protector is further included, which is connected with the power supply for detecting the phase loss or phase sequence abnormality of the power supply and triggering protection.

[0019] As the further preferred technical solution, the frequency converter controls the evaporator fan to operate at 50Hz power frequency in the refrigeration mode and controls the evaporator fan to operate at a set frequency in the dehumidification mode.

[0020] The embodiment of the application has the following advantages due to the above technical solution:

[0021] The application realizes multi-mode automatic operation and seamless switching, guarantees the continuity of temperature and humidity control in complex environments. The double-unit redundancy design significantly improves system reliability and avoids production interruption. The intelligent control logic accurately judges the defrosting demand, reduces the number of invalid defrosting, and improves the heat exchange efficiency. The variable frequency regulation technology optimizes the energy consumption ratio in different modes, reducing the overall operation cost.

[0022] The above summary is only for the purpose of the description and is not intended to limit in any way. In addition to the above described illustrative aspects, embodiments and features, further aspects, embodiments and features of the application will be readily apparent to those skilled in the art by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some of the embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative effort based on these drawings.

[0024] Figure 1 Module diagram of the system of the present application. DETAILED DESCRIPTION

[0025] The embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0026] It should be apparent that the following describes the embodiments of the present disclosure through specific concrete examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, not all. The present disclosure can also be implemented or applied by other different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present disclosure.

[0027] It should be noted that the various aspects of the embodiments described below are within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms and that any specific structure and / or function described herein is merely illustrative. Based on the disclosure, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, the devices and / or methods can be implemented using any number of the aspects set forth herein. In addition, this device and / or method can be implemented using other structures and / or functionality in addition to or other than one or more of the aspects set forth herein.

[0028] It should also be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present disclosure, and only the components related to the present disclosure are shown in the drawings, not the number, shape and size of the components when actually implemented. The shapes, numbers and proportions of each component in actual implementation can be arbitrarily changed, and the layout pattern of the components can also be more complex.

[0029] Also in the following description, specific details are given to provide thorough understanding of examples. However, one skilled in the relevant art will understand that the aspects can be practiced without these specific details.

[0030] Figure 1 is a schematic diagram of the module of the hot gas defrosting refrigeration and dehumidification integrated control system of the embodiment of the application. As shown: Figure 1 The application proposes a system including two independent refrigeration and dehumidification defrosting units, an intelligent control system and auxiliary devices. The two units can be operated in rotation, independently or simultaneously started and stopped, and the faulty unit is automatically switched when operated in rotation. Each unit includes a compressor, a condensing fan, an evaporating fan, a liquid supply valve, a refrigeration valve, a dehumidification valve, a defrosting valve, a drain heating component and a pipeline assembly. The intelligent control system includes a PLC controller, a sensor group, a frequency converter and a human-computer interaction device; the sensor group includes a temperature and humidity sensor, a pressure sensor, an evaporator temperature sensor and a defrosting termination sensor; the frequency converter is connected to the evaporating fan to adjust the rotating speed. The system can control the unit to operate in refrigeration, dehumidification, defrosting, drainage and strong cooling modes, and automatically switch the modes.

[0031] Among them, the two independent refrigeration and dehumidification defrosting units refer to two groups of refrigeration cycle devices that can be independently operated, which can be realized by connecting the compressors and heat exchanger groups in parallel, for providing redundant operation guarantee. The PLC controller in the intelligent control system refers to a programmable logic controller, which can be an industrial modular PLC, for receiving sensor signals and outputting control instructions. The evaporator temperature sensor in the sensor group refers to a device for monitoring the surface temperature of the evaporator, which can be a PT100 thermal resistance, for judging the degree of frosting. The frequency converter refers to a power control device for adjusting the rotating speed of the motor, which can be a vector frequency converter, for adjusting the rotating speed of the evaporating fan according to the operating mode.

[0032] Specifically, when the ambient temperature exceeds the set upper limit, the temperature and humidity sensor triggers the refrigeration mode to start, and the liquid supply valve and the refrigeration valve are powered on to start the compressor and the evaporating fan. The condensing fan is automatically started and stopped according to the change of pipeline pressure, and is started when the pressure is higher than the set value to reduce the system pressure. When the temperature is lower than the set lower limit, the system executes the fluorine collection shutdown process, and the liquid supply valve and the compressor are closed in turn. In the dehumidification mode, the rotating speed of the evaporating fan is adjusted to a preset frequency by the frequency converter to balance the dehumidification efficiency and energy consumption. When the defrosting mode is started, the compressor continues to operate and the evaporating fan stops, the defrosting valve is powered on to open the hot fluorine channel, and the drain heating pipe is powered on to prevent the drain from freezing.

[0033] Compared to existing technologies, the dual-unit rotational operation mechanism avoids system downtime caused by single-point failures. The combination of a sensor array and a PLC controller improves the response speed of mode switching. The variable frequency control of the evaporating fan solves the problem of low suction pressure in dehumidification mode in traditional equipment. The introduction of a pressure sensor optimizes the start and stop logic of the condensing fan. The design of continuous compressor operation during defrost reduces downtime, and the drain heating component prevents refreezing of the defrost water.

[0034] Through the above technical solution, this application achieves multi-mode automated operation and seamless switching, ensuring continuous temperature and humidity control in complex environments. The dual-unit redundant design significantly improves system reliability and avoids production interruptions. Intelligent control logic accurately determines defrost requirements, reducing the number of ineffective defrost cycles and improving heat exchange efficiency. Frequency conversion technology optimizes energy consumption ratios in different modes, reducing overall operating costs.

[0035] The present application further proposes that the rotation operation is specifically as follows: first turn on a set of refrigeration, dehumidification and defrosting units, count the running time of the compressor in the refrigeration and dehumidification states, and switch to another set of units for operation after the timing exceeds the set time; and the units can be switched manually, and one set of units will automatically switch to another set when an alarm is sounded.

[0036] Among them, rotation operation means that two sets of refrigeration, dehumidification and defrosting units perform refrigeration and dehumidification tasks alternately. It can be implemented by using the built-in timing module and switching logic module of the PLC controller, and triggering unit switching through a preset time threshold.

[0037] The set time refers to the allowed duration for the compressor to run continuously in cooling or dehumidification mode. It can be set to a fixed value through the PLC controller or dynamically adjusted according to the ambient temperature and humidity to balance the equipment load and extend component life.

[0038] Among them, manual switching refers to the operator manually selecting the operating unit through the human-computer interaction device, which can be implemented by a touch screen or buttons to respond to sudden maintenance needs or specific working condition adjustments.

[0039] Among them, automatic alarm switching means that when the operating unit triggers a fault signal, the PLC controller immediately cuts off the unit and starts the backup unit. This can be achieved through the linkage of relays and sensors to ensure the continuous operation of the system.

[0040] Specifically, during the rotation operation, first, the first set of refrigeration and dehumidification defrosting unit is started to perform the refrigeration or dehumidification task, and the PLC controller starts to accumulate the running time of the compressor at the same time. When the accumulated time reaches the preset threshold, for example, after the compressor runs continuously for several hours, the PLC controller automatically closes the first set of unit and starts the second set of unit to continue to perform the task. If the operator needs to temporarily adjust the running unit, the running main body can be manually switched through the human-machine interface. When the running unit triggers an alarm signal due to compressor overload, pipeline pressure abnormality or other reasons, the PLC controller immediately cuts off the power supply of the fault unit and activates the standby unit to take over the task, avoiding system downtime.

[0041] Compared with the prior art, the traditional system relies on a single device to operate, and once a fault occurs, the entire system will be shut down. However, the present scheme automatically switches to the standby unit when a device fails or reaches the preset running time through the rotation switching mechanism of the two independent units, without interrupting the temperature and humidity control process. The prior art lacks active switching logic based on time accumulation, which cannot balance equipment wear and tear. However, the present scheme dynamically allocates the running load through the timing module, prolonging the overall service life of the equipment.

[0042] Through the above technical scheme, the present application solves the technical problem of system downtime caused by single device failure, ensures the continuity of temperature and humidity control under complex working conditions, and reduces the running load of a single set of equipment through the timing switching mechanism, reducing the risk of component wear and tear caused by long-term high-load operation. In the industrial production scene, even if a unit fails suddenly, the standby unit can still maintain stable environmental temperature and humidity, avoiding production losses caused by downtime.

[0043] The present application further proposes a refrigeration mode operation method in a hot gas defrosting refrigeration and dehumidification integrated control system, including the following steps: when the temperature value collected by the temperature and humidity sensor is greater than the set upper limit of the temperature, delay for 5 seconds and start; the liquid supply valve and the refrigeration valve are powered on, and the compressor and the evaporative fan are powered on after 3 seconds; when the pipeline pressure is greater than the set pressure of the single high-pressure pressure controller, the condensing fan starts, and when the pipeline pressure is less than the difference between the set pressure of the single high-pressure pressure controller and the pressure bandwidth, the condensing fan stops; when the temperature value is less than the set lower limit of the temperature, delay for 5 seconds and stop fluorine collection, first power off the liquid supply valve, and after the fluorine collection is completed, power off the compressor, the condensing fan, the evaporative fan and the refrigeration valve.

[0044] Among them, the liquid supply valve refers to the valve that controls the refrigerant into the evaporator, which can be realized by an electromagnetic valve, and is used to adjust the refrigerant flow.

[0045] Among them, the refrigeration valve refers to the valve that controls the flow of refrigerant to the evaporator, which can be realized by an electromagnetic valve, and is used to open the refrigerant passage in the refrigeration mode.

[0046] The fluorine recovery shutdown refers to an operation of recovering the refrigerant in the pipeline into the compressor before shutdown, which can be specifically achieved by keeping the compressor running after the liquid supply valve is closed to avoid the refrigerant remaining in the low-pressure pipeline.

[0047] The single high-pressure controller refers to a device for monitoring the high-pressure side pressure of the refrigeration system, which can be specifically achieved by a mechanical pressure switch or an electronic pressure sensor, and is used to control the start and stop of the condensing fan according to the set pressure threshold.

[0048] The pressure bandwidth refers to the difference range of the start and stop pressures of the single high-pressure controller, for example, when the set pressure is 2.5 MPa, the pressure bandwidth can be 0.3 MPa, which is used to avoid the condensing fan frequently starting and stopping near the critical pressure.

[0049] Specifically, when the refrigeration mode is started, when the ambient temperature is detected to be higher than the set upper limit, the system excludes the interference of transient temperature fluctuation by delaying for 5 seconds, and then sequentially opens the liquid supply valve and the refrigeration valve to establish the refrigerant passage, and after an interval of 3 seconds, starts the compressor and the evaporating fan to reduce the starting current impact. The condensing fan is dynamically started and stopped according to the high-pressure side pressure: when the pressure exceeds the set value, it is started to enhance heat dissipation, and when the pressure is lower than the set value by the bandwidth difference, it is stopped to reduce energy consumption. During the shutdown process, after the temperature is lower than the set lower limit, the system delays for 5 seconds to confirm the temperature stability, first closes the liquid supply valve to block the refrigerant flow, and then cuts off the power supply of the compressor, fan and valve after the compressor recovers the low-pressure side refrigerant to the high-pressure side, to complete the safe shutdown.

[0050] Compared with the prior art, the existing refrigeration mode control logic lacks a pressure linkage mechanism, and the condensing fan usually continuously runs or only depends on the temperature signal to start and stop, resulting in high energy consumption and unstable heat dissipation efficiency. The scheme cooperates the pressure sensor and the single high-pressure controller to make the condensing fan run only when the high-pressure side is overpressure, and introduces the pressure bandwidth parameter to avoid critical state jitter, which significantly reduces the invalid energy consumption. In addition, the prior art directly cuts off the power supply during shutdown, which easily causes the refrigerant to remain, and the scheme recovers the refrigerant to the high-pressure side through the fluorine recovery operation to avoid the leakage risk caused by the refrigerant remaining in the low-pressure pipeline.

[0051] Through the above technical scheme, the present application solves the problems of low running efficiency of the condensing fan in the traditional refrigeration mode and uneven distribution of the refrigerant during shutdown, realizes accurate control of the refrigerant flow and dynamic balance of the pressure, reduces the energy consumption of the system, prolongs the service life of the compressor, and avoids the increase of maintenance cost caused by the refrigerant remaining.

[0052] The application further proposes that the operation process of the dehumidification mode is: when the humidity value collected by the temperature and humidity sensor is greater than the set upper limit of humidity, and the temperature value is between the set upper and lower limits of temperature, it is started; the liquid supply valve and the dehumidification valve are powered on, and the compressor and the evaporative fan are powered on after 3 seconds; the condensing fan is started and stopped according to the pipeline pressure according to the logic described in the refrigeration mode; when the humidity value is less than the set lower limit of humidity, and the temperature value is between the set upper and lower limits of temperature, it is stopped after 5 seconds of delay, and the liquid supply valve, the dehumidification valve, the compressor, the condensing fan and the evaporative fan are all powered off.

[0053] Among them, the liquid supply valve refers to the electromagnetic valve that controls the supply of refrigerant to the evaporator, which can be realized by a normally closed electromagnetic valve, and is used to open the refrigerant circulation path when the dehumidification mode is started. The dehumidification valve refers to the valve that controls the flow direction of the refrigerant on the evaporator side, which can be realized by a three-way electromagnetic valve, and is used to guide the refrigerant to the evaporator for dehumidification heat exchange. The condensing fan start-stop logic refers to dynamically controlling the fan operation according to the high-pressure pipeline pressure value, for example, starting the fan to dissipate heat when the pressure exceeds the set upper limit, and stopping the fan when the pressure is lower than the set lower limit and the pressure bandwidth difference, which can match the system load change. The 5-second delay stop mechanism refers to reserving refrigerant recovery time before stopping, for example, triggering the power-off instruction through the PLC timing module, to avoid liquid refrigerant remaining in the pipeline.

[0054] Specifically, when the environmental humidity exceeds the preset threshold and the temperature is in the safe operation interval, the liquid supply valve and the dehumidification valve are synchronously opened to establish the refrigerant path, and the compressor and the evaporative fan are started after a delay of 3 seconds to form a dehumidification cycle. The condensing fan is automatically started and stopped according to the real-time detected high-pressure pipeline pressure value, for example, it is started to forcibly dissipate heat when the pressure reaches, for example, 2.5 MPa, and it is stopped when the pressure falls to, for example, 2.3 MPa. When the humidity decreases to the target value and the temperature is still within the set range, the system maintains a 5-second fluorine recovery time before cutting off the power supply of all components, ensuring that the refrigerant is completely recovered to the liquid accumulator. This process controls through temperature and humidity double parameter interlocking, avoiding frequent start-stop caused by single parameter misjudgment.

[0055] Compared with the prior art, the traditional equipment only relies on humidity single parameter control start-stop in dehumidification mode, which is easy to cause short period operation of the compressor due to temperature fluctuation. The present scheme restricts the temperature upper and lower limits, for example, limits the dehumidification operation only within the range of 15-30℃, which prevents frost formation at low temperature and avoids overload at high temperature. In the prior art, the condensing fan is mostly operated at a constant speed, and the variable speed control based on pressure feedback in the present scheme can reduce auxiliary energy consumption by, for example, 35%, while maintaining stable system pressure.

[0056] By the technical solution, the application solves the problem of low energy efficiency caused by rough parameter adjustment of the traditional dehumidification equipment, ensures that the dehumidification operation is only performed in a suitable temperature range through the temperature and humidity interlocking control, and reduces invalid energy consumption while ensuring the dehumidification efficiency through the pressure self-adaptive condensing fan control strategy. The mode avoids the risk of evaporator frosting caused by blind start of dehumidification in a low-temperature environment and the compressor overload hidden danger in a high-temperature working condition, and significantly improves the system operation reliability.

[0057] The application further proposes that the operation process of the defrosting mode is: based on the temperature value detected by the evaporator temperature sensor, the defrosting cycle timing of the compressor running time in the refrigeration or dehumidification mode is performed, and the defrosting is started when the timing reaches the set defrosting cycle time; the compressor keeps running, and the evaporative fan stops; the refrigeration valve or the dehumidification valve is powered off after a delay of 3 seconds, the defrosting valve is powered on, and the water pan heating pipe is powered on; the condensing fan is started and stopped according to the pipe pressure by the difference between the set pressure of the single high-pressure pressure controller and the pressure bandwidth; when the defrosting timing is greater than the set defrosting time or the defrosting termination sensor detects that the temperature is greater than the set stop temperature, the defrosting is terminated, the defrosting valve and the compressor are powered off, and the drainage mode is entered.

[0058] Among them, the defrosting cycle timing refers to triggering the defrosting operation according to the cumulative running time of the compressor in the refrigeration or dehumidification mode, which can be realized by using the timing module built in the PLC controller, so as to avoid that the excessive frosting of the evaporator affects the heat exchange efficiency.

[0059] Among them, the defrosting termination sensor refers to a device for detecting the temperature of the evaporator surface, which can be realized by using the F2000 temperature controller, and the defrosting process is automatically terminated when the detected temperature exceeds the set threshold, so as to prevent excessive heating from increasing energy consumption.

[0060] Among them, the evaporative fan stopping refers to closing the air circulation on the evaporator side during the defrosting process, which can be realized by cutting off the power supply through the frequency converter, so as to avoid that the mixing of cold and hot air affects the defrosting effect.

[0061] Specifically, in the refrigeration or dehumidification mode, when the cumulative running time of the compressor reaches the preset defrosting cycle (for example, 4 hours), the PLC controller immediately starts the defrosting mode. At this time, the compressor continues to run, the evaporative fan stops working, and the refrigeration valve or the dehumidification valve is closed after a delay of 3 seconds, while the defrosting valve is opened to make the high-temperature refrigerant enter the evaporator, and the water pan heating pipe is powered on to melt the ice and frost. The condensing fan is automatically started and stopped according to the change of the pipe pressure: it is started when the pressure exceeds the set value of the single high pressure (for example, 2.5 MPa), and it is stopped when the pressure is lower than the difference between the set value and the pressure bandwidth (for example, 2.5 MPa-0.3 MPa). The defrosting process is terminated through double conditions: if the defrosting timing reaches the preset length of time (for example, 10 minutes), or the temperature detected by the defrosting termination sensor exceeds the set threshold (for example, 15℃), the defrosting valve and the compressor are turned off, and the drainage mode is entered.

[0062] Compared with the prior art, the traditional defrosting needs to be executed in a shutdown state and relies on a single temperature judgment, while the scheme completes the defrosting in a continuous running state of the compressor, avoids system interruption, and improves the defrosting termination judgment accuracy through a dual control mechanism of running time and temperature sensor. For example, the prior art needs to close the compressor and rely on manual observation of ice thickness during defrosting, while the scheme realizes accurate defrosting through real-time monitoring by the evaporator temperature sensor combined with timing logic.

[0063] Through the above technical solution, the application solves the problem of running efficiency reduction caused by shutdown during defrosting under low temperature working conditions, and prevents energy waste caused by insufficient or excessive heating during defrosting. For example, in cold storage applications, the defrosting process does not need to interrupt the refrigeration work, and the temperature stability in the warehouse can be maintained; during the defrosting termination stage, the sensor and timer are cooperatively controlled to accurately judge the ice melting state, and the evaporator is prevented from being damaged due to excessive heating.

[0064] The application further proposes that the running process of the drainage mode is to only power on the water pan heating pipe and the drainage pipeline heating wire, and the remaining components are powered off; the strong cooling mode runs after the drainage mode ends, the liquid supply valve and the refrigeration valve are powered on, the compressor is powered on after 3 seconds, the condenser fan is started and stopped according to the pipeline pressure according to the logic in claim 3, and the evaporator fan is not running.

[0065] The water pan heating pipe refers to an electric heating element installed in the water pan below the evaporator, which can be realized by winding a nickel-chromium alloy resistance wire around a ceramic pipe, and is used to melt the ice produced during defrosting and heat the drainage channel to prevent secondary icing.

[0066] The drainage pipeline heating wire refers to a heat tracing tape laid along the outer wall of the drainage pipe, which can be realized by a self-limiting temperature electric heating tape, and is used to maintain the temperature in the drainage pipe above the freezing point to avoid drainage freezing and blockage.

[0067] The strong cooling mode refers to a working state in which the evaporator fan is turned off and the compressor is kept running, which can be realized by cutting off the power supply circuit of the evaporator fan through the PLC controller and keeping the refrigerant circulating, and using the natural convection of the evaporator for rapid cooling.

[0068] Specifically, when the drainage mode is started, the water pan heating pipe and the drainage pipeline heating wire are powered on, and the remaining components remain in a power-off state. The water pan heating pipe heats the ice-water mixture generated by defrosting to a liquid state through heat conduction, and the drainage pipeline heating wire continuously heats the outer wall of the drainage pipe to ensure that the liquid water is smoothly discharged from the system during the drainage process. The strong cooling mode is automatically triggered after the drainage mode ends, the liquid supply valve and the refrigeration valve are powered on, the compressor is started after 3 seconds, the condenser fan is automatically started and stopped according to the change of pipeline pressure, and the evaporator fan remains in a closed state. The continuous operation of the compressor circulates the refrigerant in the evaporator to absorb heat, and the natural convection of the evaporator surface and the air is used to cool down, avoiding the loss of cold energy caused by the operation of the evaporator fan.

[0069] Compared with the prior art, the traditional equipment often causes poor drainage due to frozen drainage channels after defrosting, and manual intervention is required for cleaning or defrosting time is extended. However, the present application realizes efficient drainage of defrosting water by independently controlling the water pan heating pipe and the drainage pipeline heating wire. In the prior art, the evaporator fan needs to be started synchronously when restarting the refrigeration after defrosting, which causes delay in cooling. However, the present application closes the evaporator fan in the strong cooling mode, uses natural convection to quickly reduce the temperature of the evaporator, and reduces the loss of cold energy.

[0070] Through the above technical solutions, the present application solves the problems of frozen drainage channels after defrosting and low cooling efficiency when restarting the refrigeration, ensures smooth drainage and rapid recovery of low-temperature environment in the strong cooling mode, and avoids system failure and cold energy waste caused by drainage blockage.

[0071] The present application further proposes that the intelligent control system further comprises a remote communication module connected with the PLC controller, for real-time transmission of system operation data and sending of alarm messages.

[0072] The remote communication module refers to a communication component capable of data interaction with external devices or networks, which can be implemented by a 4G module, a Wi-Fi module or an Ethernet module, for uploading the operation data collected by the PLC controller to the cloud or a local monitoring platform, and automatically sending alarm information when the system fails. The PLC controller refers to a programmable logic controller, which can be implemented by an industrial-grade embedded controller, for receiving temperature, humidity, pressure and temperature signals collected by the sensor group, and driving the compressor, valve and fan to perform actions according to the preset control logic.

[0073] Specifically, the remote communication module establishes a data connection with the PLC controller through an RS485 or Ethernet interface, and obtains the compressor operating state, pipeline pressure, evaporator temperature, defrosting state and alarm code information in real time. When the sensor group detects pressure overrun, temperature anomaly or equipment failure, the PLC controller generates an alarm signal and sends it to the preset terminal through the remote communication module. For example, when the compressor overload or defrost termination sensor is triggered, the alarm message can include the fault code, occurrence time and associated device number, facilitating remote diagnosis by maintenance personnel. The operating data can be uploaded at a set period to form a historical record for the analysis system to analyze energy consumption and operating trends.

[0074] Compared with the prior art, the traditional device lacks remote monitoring capability, and fault alarm relies on on-site sound and light prompts or manual inspection, which can easily lead to delayed response. The present scheme solves the problems of lagging maintenance and low fault handling efficiency of the traditional system by integrating a remote communication module, so that operating data can be transmitted to a remote server in real time, and alarm information can be pushed to a mobile terminal in real time.

[0075] Through the above technical scheme, the present application realizes remote real-time monitoring of the operating state of the device, shortens the fault response time, and avoids the risk of system downtime caused by manual inspection omissions. Maintenance personnel can retrieve historical data through a cloud platform, optimize device operating parameters, and improve system maintenance efficiency and reliability.

[0076] The present application further proposes that the pressure sensor in the sensor group includes a high-pressure pressure sensor and a low-pressure pressure sensor for detecting the exhaust pressure and the suction pressure of the system pipeline; the defrost termination sensor is an F2000 temperature controller, and the evaporator temperature sensor is a PT100 sensor.

[0077] The high-pressure pressure sensor is a device for detecting the pressure of the refrigerant on the exhaust side of the compressor, which can be implemented by a piezoresistive sensor, and its function is to monitor the pressure change in the high-pressure area of the pipeline in real time to prevent equipment damage caused by excessively high exhaust pressure.

[0078] The low-pressure pressure sensor is a device for detecting the pressure of the refrigerant on the suction side of the compressor, which can be implemented by a capacitive sensor, and its function is to monitor the pressure change in the low-pressure area of the pipeline in real time to avoid abnormal shutdown of the compressor caused by excessively low suction pressure.

[0079] The F2000 temperature controller is a temperature controller for determining the defrost termination condition, which can be implemented by a bimetallic strip contact structure, and its function is to accurately detect the surface temperature of the evaporator to ensure that the defrosting process is terminated in time at the set temperature threshold, thereby avoiding energy waste.

[0080] The PT100 sensor is a resistance temperature sensor for measuring the temperature of the evaporator, and can be implemented by a platinum resistance element, which provides high-precision temperature data to provide a reliable basis for defrosting cycle calculation and mode switching.

[0081] Specifically, the high-pressure pressure sensor and the low-pressure pressure sensor are installed at the pipeline positions corresponding to the discharge port and the suction port of the compressor, respectively, to realize closed-loop monitoring of the circulating pressure of the refrigerant by collecting pressure data in real time and transmitting them to the control system. The F2000 temperature controller is fixed to the surface of the evaporator fins, and when the temperature of the evaporator rises to a set threshold during the defrosting process, the internal contact is disconnected and a termination signal is sent. The PT100 sensor is embedded in the evaporator coil, which accurately reflects the core temperature of the evaporator through resistance value changes, and triggers or terminates the defrosting operation in combination with a pre-set defrosting cycle algorithm.

[0082] Compared with the prior art, the traditional system is usually configured with only a single pressure sensor or uses a temperature control device with low precision, which cannot comprehensively monitor the pressure state of the high and low pressure areas, and the defrosting termination judgment relies on experience values or rough temperature detection, which is easy to cause insufficient or excessive defrosting. The present scheme realizes fine control of the system pressure and defrosting state through the cooperative detection of the high and low pressure sensors, combined with the high-precision temperature feedback of the PT100 sensor and the F2000 temperature controller.

[0083] Through the above technical scheme, the present application solves the problem of insufficient system stability caused by incomplete pressure monitoring of the existing equipment, avoids energy waste caused by temperature detection errors during the defrosting process, and improves the reliability of defrosting triggering and termination through accurate evaporator temperature data, ensuring efficient operation of the system under complex working conditions.

[0084] The present application further proposes a phase loss / phase sequence protector, which is connected with the power supply and is used for detecting phase loss or phase sequence anomaly of the power supply and triggering protection.

[0085] The phase loss / phase sequence protector is a safety protection device for monitoring the state of a three-phase power supply, which can be implemented by combining a voltage detection circuit and a logic judgment module, and detecting the amplitude and phase relationship of each phase voltage to determine the abnormality of the power supply. The phase sequence anomaly detection function is realized by comparing the phase sequence of three-phase voltage, and the protection action is triggered when reverse phase sequence is detected. The phase loss detection function starts protection when any phase voltage is missing or below a threshold, which can be implemented by using a voltage transformer and a comparator circuit.

[0086] Specifically, the protection device is configured at the input end of the system power supply, and the voltage signals of the three-phase power supply are obtained in real time through a voltage sampling circuit. When any one-phase voltage is missing or the three-phase sequence is incorrect, the relay contact inside the protector is disconnected, cutting off the power supply of the main circuit. Before the compressor starts, the protector performs a pre-check program, and if a phase sequence error is detected, the compressor is prevented from being powered on to avoid damage caused by motor reverse rotation. After the protection action is triggered, the system enters a fault-locked state, and needs to be manually reset to resume operation.

[0087] In some embodiments, the protector can integrate an acousto-optic alarm module to output an alarm signal when the protection is triggered. The voltage detection threshold of the protector can be set to 70%-85% of the rated voltage, for example, in a 380V system, the missing phase detection threshold is set to 270V. The phase sequence judgment adopts a digital signal processor to calculate the phase angle in real time, and the detection accuracy can reach ±2 degrees.

[0088] Compared with the prior art, the traditional refrigeration system usually uses an independent circuit breaker for overload protection, but lacks the ability to monitor the phase sequence of the power supply. When a phase sequence error occurs, the compressor motor may run in reverse, causing mechanical damage, and conventional protection devices cannot identify such faults. The present scheme integrates phase detection and missing phase protection functions, which can cut off the circuit at the initial stage of power supply abnormalities, preventing equipment damage.

[0089] Through the above technical solutions, the present application effectively prevents problems such as compressor motor stall and winding overheating caused by power phase error or loss, and reduces the failure rate of equipment caused by abnormal power supply. In the scenario of unstable power supply environment in industrial field, the protection mechanism can avoid unplanned shutdown of the system, and ensure the continuous and reliable operation of the refrigeration and dehumidification defrosting system.

[0090] The present application further proposes that the frequency converter controls the evaporative fan to run at 50Hz power frequency in refrigeration mode, and controls the evaporative fan to run at a set frequency in dehumidification mode.

[0091] Wherein, the frequency converter refers to an electric power control device that adjusts the motor speed by changing the power frequency, which can be realized by using a three-phase AC frequency converter driver, and the output frequency can be programmed to adjust the range of 5-60Hz. Running at power frequency in refrigeration mode can ensure stable wind speed on the evaporator surface and maintain optimal heat exchange efficiency; running at a set frequency in dehumidification mode can avoid the problem of too low suction pressure caused by overcooling on the evaporator surface.

[0092] Wherein, 50Hz power frequency operation refers to running the evaporative fan at the standard frequency of the power grid, which can be realized by using the fixed frequency output mode of the frequency converter. In this mode, the fan speed is constant and matches the refrigeration load.

[0093] The set frequency operation refers to a non-power frequency operation parameter set in advance according to the dehumidification working condition requirement. Specifically, the frequency value can be input through a man-machine interaction device, for example, the frequency is set to the interval of 30-45 Hz. The set value needs to ensure that the evaporator surface wind speed can maintain the dehumidification efficiency and prevent excessive cooling.

[0094] Specifically, when the refrigeration mode is activated, the frequency converter automatically switches to the power frequency output mode to drive the evaporative fan to operate at the rated speed. At this time, a stable airflow field is formed on the surface of the evaporator, ensuring that the refrigerant fully absorbs heat. When the system switches to the dehumidification mode, the frequency converter reduces the fan speed according to the preset frequency value, slows down the air flow rate through the evaporator, prolongs the contact time between air and the evaporator to improve the dehumidification efficiency, and at the same time avoids the sudden drop of suction pressure caused by the low temperature of the evaporator surface. The set value of the operating frequency can be dynamically adjusted according to the change of environmental humidity, for example, 40 Hz is used when the humidity is higher than 75%, and 35 Hz is used when the humidity is between 60% and 75%.

[0095] Compared with the prior art, the conventional equipment uses a fixed speed fan in the refrigeration and dehumidification modes, which causes the evaporator surface to be too cold and causes the suction pressure to be abnormal, and an additional pressure protection device needs to be configured. The present scheme controls the fan speed through the frequency converter in different modes, optimizes the airflow parameters in the dehumidification working condition while maintaining the refrigeration performance, and solves the problem of pressure fluctuation without the need to add a complex protection mechanism.

[0096] Through the above technical scheme, the present application realizes the differential control of the evaporative fan speed in the refrigeration and dehumidification modes, which not only maximizes the refrigeration efficiency, but also suppresses the overcooling of the evaporator by reducing the fan speed during dehumidification, so that the suction pressure is stabilized within a safe range, and the fan energy consumption is reduced by about 20%-30%.

[0097] It should be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of the present disclosure.

[0098] Various changes, substitutions and alterations can be made to the technology described herein without departing from the teachings of the technology defined by the appended claims. Also, the scope of the claims of the present disclosure is not limited to specific aspects of the process, machine, manufacture, composition of matter, means, methods and actions described herein. Processes, machines, manufacture, compositions of matter, means, methods or actions currently existing or later developed that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Accordingly, the appended claims include within their scope such processes, machines, manufacture, compositions of matter, means, methods or actions.

[0099] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0100] The above description has been presented to enable any person skilled in the art to make or use the disclosure. Furthermore, the purpose of the above description is not intended to limit the embodiments of the present disclosure to the form disclosed herein. Although various example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations of the described aspects and embodiments.

Claims

1. Hot gas defrosting, refrigeration and dehumidification integrated control system, characterized in that: include: Two independent refrigeration, dehumidification and defrosting units, intelligent control systems and auxiliary devices; The two sets of refrigeration, dehumidification and defrosting units can realize rotation operation, independent operation or simultaneous start and stop. When rotating operation is carried out, if one of the units fails, the other unit will automatically switch to operation; Each set of the refrigeration, dehumidification and defrosting unit includes a compressor, a condensing fan, an evaporating fan, a liquid supply valve, a refrigeration valve, a dehumidification valve, a defrost valve, a drainage heating component and a pipeline assembly; The intelligent control system includes a PLC controller, a sensor group, a frequency converter and a human-computer interaction device; the sensor group includes a temperature and humidity sensor, a pressure sensor, an evaporator temperature sensor and a defrost termination sensor; the frequency converter is connected to the evaporation fan to adjust the speed of the evaporation fan; The intelligent control system can control the refrigeration, dehumidification and defrosting unit to operate in refrigeration mode, dehumidification mode, defrosting mode, drainage mode and strong cooling mode, and realize automatic switching between the modes.

2. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 1, characterized in that: The rotation operation is specifically as follows: first turn on a set of refrigeration, dehumidification and defrosting units, count the running time of the compressor in the refrigeration and dehumidification states, and switch to another set of units for operation after the timing exceeds the set time; and the units can be switched manually, and one set of units will automatically switch to another set when an alarm is sounded.

3. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 1, characterized in that: The operation process of the refrigeration mode is as follows: when the temperature value collected by the temperature and humidity sensor is greater than the set temperature upper limit, it will start after a delay of 5 seconds; the liquid supply valve and the refrigeration valve will be energized, and the compressor and the evaporating fan will be energized 3 seconds later; when the pipeline pressure is greater than the set pressure of the single high-pressure pressure controller, the condensing fan will start, and when the pipeline pressure is less than the difference between the set pressure of the single high-pressure pressure controller and the pressure bandwidth, the condensing fan will stop; when the temperature value is less than the set temperature lower limit, the fluorine collection and shutdown will be delayed for 5 seconds, the liquid supply valve will be de-energized first, and after the fluorine collection is completed, the compressor, condensing fan, evaporating fan and refrigeration valve will be de-energized.

4. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 1, characterized in that: The operation process of the dehumidification mode is as follows: when the humidity value collected by the temperature and humidity sensor is greater than the set humidity upper limit and the temperature value is between the set temperature upper and lower limits, it starts; the liquid supply valve and the dehumidification valve are energized, and after 3 seconds, the compressor and the evaporating fan are energized; the condensing fan is started and stopped according to the logic described in claim 3 based on the pipeline pressure; when the humidity value is less than the set humidity lower limit and the temperature value is between the set temperature upper and lower limits, it stops after a delay of 5 seconds, and the liquid supply valve, dehumidification valve, compressor, condensing fan, and evaporating fan are all powered off.

5. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 4, characterized in that: The operation process of the defrost mode is as follows: based on the temperature value detected by the evaporator temperature sensor, the defrost cycle time is counted for the compressor operation time in the refrigeration or dehumidification mode, and the defrost cycle is started when the time reaches the set defrost cycle time; the compressor keeps running and the evaporating fan stops; the refrigeration valve or dehumidification valve is powered off after a delay of 3 seconds, the defrost valve is powered on, and the water receiving pan heating pipe is powered on; the condensing fan is started and stopped according to the logic described in claim 3 based on the pipeline pressure; when the defrost timer is greater than the set defrost time or the temperature detected by the defrost termination sensor is greater than the set stop temperature, the defrost is terminated, the defrost valve and the compressor are powered off, and the system enters the drainage mode.

6. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 5, characterized in that: The operation process of the drainage mode is: only the water pan heating pipe and the drainage pipe heating wire are energized, and the other components are de-energized; the strong cooling mode is operated after the drainage mode ends, the liquid supply valve and the refrigeration valve are energized, and the compressor is energized after 3 seconds. The condensing fan is started and stopped according to the logic described in claim 3 based on the pipeline pressure, and the evaporating fan does not run.

7. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 1, characterized in that: The intelligent control system further comprises a remote communication module, which is connected to the PLC controller and is used for real-time transmission of system operation data and sending alarm messages.

8. According to the hot gas defrost refrigeration and dehumidification integrated control system according to claim 1, the pressure sensors in the sensor group include a high-pressure pressure sensor and a low-pressure pressure sensor, which are used to detect the exhaust pressure and intake pressure of the system pipeline; the defrost termination sensor is an F2000 thermostat, and the evaporator temperature sensor is a PT100 sensor.

9. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 1 further includes a phase loss / phase sequence protector, which is connected to the power supply and is used to detect power phase loss or abnormal phase sequence and trigger protection.

10. The hot gas defrosting, refrigeration and dehumidification integrated control system according to claim 1, wherein the inverter controls the evaporation fan to operate at a working frequency of 50 Hz in the cooling mode, and controls the evaporation fan to operate at a set frequency in the dehumidification mode.

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