CN110440491B - Control method and device of refrigeration system - Google Patents
Control method and device of refrigeration system Download PDFInfo
- Publication number
- CN110440491B CN110440491B CN201910667197.7A CN201910667197A CN110440491B CN 110440491 B CN110440491 B CN 110440491B CN 201910667197 A CN201910667197 A CN 201910667197A CN 110440491 B CN110440491 B CN 110440491B
- Authority
- CN
- China
- Prior art keywords
- temperature
- output quantity
- delta
- temperature difference
- inlet end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Air Conditioning Control Device (AREA)
- Devices That Are Associated With Refrigeration Equipment (AREA)
Abstract
The invention provides a control method and a device of a refrigerating system, wherein the control method comprises the following steps: comparing a first temperature differential Δ T1 between the inlet end temperature and the outlet end temperature of the evaporator to a first target temperature differential value T10; if the delta T1 is greater than T10+ n, the PID controller reduces the output quantity; if the delta T1 is less than T10-n, the PID controller increases the output quantity; obtaining N groups of first temperature differences delta T1 by continuously adjusting the output quantity until T10-N is less than delta T1 is less than T10+ N, and keeping the output quantity unchanged; comparing a second temperature difference Δ T2 obtained by the evaporating temperature of the refrigerant and the set point temperature with a second target temperature difference value T20; if the delta T2 is greater than T20+ m, the PID controller reduces the output quantity; if the delta T2 is less than T20-m, the PID controller increases the output quantity; obtaining M groups of second temperature differences delta T2 by continuously adjusting the output quantity until T20-M is less than delta T2 is less than T20+ M, and keeping the output quantity unchanged; selecting the smaller output quantity in the two steps as the final output quantity; the opening of the throttling element is controlled based on the final output quantity. The invention can realize the temperature intellectualization and the continuous adjustment of the refrigeration system.
Description
Technical Field
The invention relates to the technical field of refrigeration system control, in particular to a control method and device of a refrigeration system.
Background
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
At present, the traditional PID algorithm based on temperature deviation has serious defects in the mechanical refrigeration application. Specifically, the conventional PID algorithm determines the output amount based on the difference between the temperature set value (SP) and the temperature actual value (PV). For example, in one illustrative scenario, the PID algorithm determines that the output is 100% if the cooling temperature is desired to be reduced from the current 150 ℃ to-70 ℃ (the temperature is reduced to 220 ℃). At this point, the capillary tube is opened at maximum flux and the freon flow rate increases dramatically in order to reach the desired refrigeration temperature. However, due to the relationship between the Freon evaporation temperature and the evaporation pressure, too large a flow rate causes the evaporation pressure to be high, and the evaporation temperature to increase, so that the temperature cannot be lowered to-70 ℃. In addition, high evaporating pressure results in high return pressure, which adversely affects the normal operation and life of the compressor.
At present, the above problems are generally solved by arranging a plurality of groups of refrigeration pipelines, and based on the expected refrigeration temperature and the current temperature to be reached, the pressure of a high-temperature section system is reduced by artificially reducing the corresponding refrigeration pipelines, so that the evaporation pressure of a low-temperature section is reduced, and the lower temperature is realized.
However, the above solution requires manual adjustment, and the intelligence needs to be further improved. In addition, the increase or decrease in the number of the cooling pipes tends to cause a transition in the cooling temperature, and it is difficult to achieve continuous temperature control.
It should be noted that the above background description is only for the sake of clarity and complete description of the technical solutions of the present invention and for the understanding of those skilled in the art. Such solutions are not considered to be known to the person skilled in the art merely because they have been set forth in the background section of the invention.
Disclosure of Invention
Based on the foregoing defects in the prior art, embodiments of the present invention provide a method and an apparatus for controlling a refrigeration system, which can achieve intelligent and continuous temperature adjustment of the refrigeration system.
In order to achieve the above object, the present invention provides the following technical solutions.
A control method of a refrigeration system comprises a throttling element, an evaporator and a compressor which are connected in sequence, wherein the throttling element is controlled by a PID controller; the method comprises the following steps:
step S10: comparing a first temperature differential Δ T1 derived based on an inlet end temperature and an outlet end temperature of the evaporator to a first target temperature differential value T10; if Δ T1> T10+ n, PID controller turndown output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10; a PID controller turn up output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10 if Δ T1< T10-n; obtaining N groups of first temperature differences delta T1 by continuously adjusting the output quantity, and keeping the output quantity unchanged until T10-N is less than delta T1 and less than T10+ N;
step S20: comparing a second temperature difference Δ T2, which is obtained based on the evaporation temperature of the refrigerant and the set point temperature, with a second target temperature difference value T20; if Δ T2> T20+ m, PID controller turndown output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20; a PID controller turn up output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20 if Δ T2< T20-m; obtaining M groups of second temperature differences delta T2 by continuously adjusting the output quantity until T20-M is less than delta T2 is less than T20+ M, and keeping the output quantity unchanged;
step S30: selecting the smaller output quantity in step S10 and step S20 as the final output quantity;
step S40: controlling an opening degree of the throttling element based on the final output quantity.
Preferably, the first temperature difference Δ T1 is obtained by:
the inlet end temperature and the outlet end temperature of the evaporator are collected in real time, and the first temperature difference delta T1 is obtained based on the collected inlet end temperature and outlet end temperature of the evaporator.
Preferably, the second temperature difference Δ T2 is obtained by:
and acquiring the inlet end temperature of the compressor in real time, and acquiring the second temperature difference delta T2 based on the acquired inlet end temperature of the compressor and the set value temperature.
Preferably, the second temperature difference Δ T2 is obtained by:
and acquiring an inlet end pressure value of the compressor in real time, converting the inlet end pressure value of the compressor to obtain a return air end temperature, and acquiring a second temperature difference delta T2 based on the return air end temperature and the set value temperature.
A control device of a refrigeration system comprises a throttling element, an evaporator and a compressor which are connected in sequence, wherein the throttling element is controlled by a PID controller; the method comprises the following steps:
a first adjustment module to compare a first temperature differential Δ T1 derived based on an inlet end temperature and an outlet end temperature of the evaporator to a first target temperature differential value T10; if Δ T1> T10+ n, PID controller turndown output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10; a PID controller turn up output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10 if Δ T1< T10-n; obtaining N groups of first temperature differences delta T1 by continuously adjusting the output quantity, and keeping the output quantity unchanged until T10-N is less than delta T1 and less than T10+ N;
a second adjusting module for comparing a second temperature difference Δ T2 obtained based on the evaporation temperature of the refrigerant and the set point temperature with a second target temperature difference value T20; if Δ T2> T20+ m, PID controller turndown output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20; a PID controller turn up output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20 if Δ T2< T20-m; obtaining M groups of second temperature differences delta T2 by continuously adjusting the output quantity until T20-M is less than delta T2 is less than T20+ M, and keeping the output quantity unchanged;
the selection module is used for selecting the smaller output quantity obtained by the first regulation module and the second regulation module as the final output quantity;
and the control module is used for controlling the opening of the throttling element based on the final output quantity.
Preferably, the system further comprises an evaporator temperature acquisition module for acquiring the inlet end temperature and the outlet end temperature of the evaporator in real time; the first temperature difference Δ T1 is obtained based on the collected inlet end temperature and outlet end temperature of the evaporator.
Preferably, the control device further comprises a compressor temperature acquisition module for acquiring the inlet end temperature of the compressor in real time; and obtaining the second temperature difference delta T2 based on the collected inlet end temperature of the compressor and the set point temperature.
Preferably, the control device further includes a return air pressure acquisition module, configured to acquire an inlet end pressure value of the compressor in real time, convert the inlet end pressure value of the compressor to obtain a return air end temperature, and obtain the second temperature difference Δ T2 based on the return air end temperature and the set value temperature.
According to the control method and device of the refrigeration system, PID calculation is carried out through the difference value between the first temperature difference delta T1 based on the inlet end temperature and the outlet end temperature of the evaporator and the first target temperature difference value T10, corresponding output quantity is adjusted and output, and the first temperature difference delta T1 between the inlet end temperature and the outlet end temperature of the evaporator is in a proper range; and adjusting and outputting a corresponding output quantity in combination with the PID calculated by PID based on the second temperature difference Δ T2 and the second target temperature difference value T20. Therefore, the problem that the low-temperature section cannot reach due to overlarge temperature drop is avoided, the situation that the refrigerant evaporation pressure is overlarge due to the overlow expected refrigerating temperature and then the condition that the refrigeration is interrupted by alarming and even the compressor is damaged is avoided, and the temperature of the refrigerating system is intelligently and continuously adjusted.
Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not so limited in scope.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.
It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.
Drawings
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for facilitating the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. Those skilled in the art, having the benefit of the teachings of this invention, may choose from the various possible shapes and proportional sizes to implement the invention as a matter of case. In the drawings:
fig. 1 is a flowchart of a control method of a refrigeration system according to an embodiment of the present invention;
fig. 2 is a structural view of a control device of the refrigeration system according to the embodiment of the present invention;
fig. 3 is a block diagram of a control apparatus of a refrigeration system according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The embodiment of the invention provides a control method and device of a refrigerating system. The refrigeration system comprises a throttling element, an evaporator and a compressor which are sequentially connected through a pipeline, and of course, the refrigeration system also comprises a condenser connected between the throttling element and the compressor. The throttling element can be an expansion valve or a capillary tube, and can be controlled by a PID controller to realize opening degree adjustment.
As shown in fig. 1 and 2, the control method of the refrigeration system according to the embodiment of the present invention includes the steps of:
step S10: comparing a first temperature differential Δ T1 based on the inlet end temperature and the outlet end temperature of the evaporator to a first target temperature differential value T10; if Δ T1> T10+ n, PID controller turndown output is PID calculated based on the first temperature difference Δ T1 and the first target temperature difference T10; if Δ T1< T10-n, PID controller turn up output based on PID calculations of the first temperature difference Δ T1 and the first target temperature difference T10; n groups of first temperature differences delta T1 are obtained by continuously adjusting the output quantity, and the output quantity is kept unchanged until T10-N is less than delta T1 and less than T10+ N.
In this embodiment, the temperature acquisition of the inlet end and the outlet end of the evaporator can be realized in real time through the evaporator temperature acquisition module. The evaporator temperature collecting module may include two temperature collecting elements (e.g., temperature sensors, thermocouples, etc.) respectively disposed at the inlet end and the outlet end of the evaporator, for respectively collecting an inlet end temperature t (in) and an outlet end temperature t (out) of the evaporator. Based on the inlet end temperature T (in) and the outlet end temperature T (out) of the evaporator, a first temperature difference Δ T1 is obtained.
In this step, the PID Controller (PID _ Controller) performs PID calculation based on a difference between the first temperature difference Δ T1 and the first target temperature difference value T10. The proportional coefficient Kp, the differential coefficient Ki, and the differential coefficient Kd involved in the proportional, differential, and differential control processes included in the calculation process of the PID controller are adaptively adjusted and set according to actual conditions, which is not limited in the embodiment of the present invention.
In this embodiment, the first target temperature difference T10 and the value n may be set according to actual conditions, which is not limited in this embodiment of the present invention, for example, the first target temperature difference T10 may be 10 ℃ and n may be 3 ℃. The PID calculation is carried out based on the difference value between the first temperature difference delta T1 and the first target temperature difference value T10, so that the problem that the low-temperature section cannot be reached due to excessive temperature drop is solved.
The heat absorption of the refrigerant (including but not limited to Freon) in the evaporator is the key to the refrigeration effect of the refrigeration system. Therefore, whether the temperature control of the refrigeration system reaches a steady state is determined by considering the temperature difference between the inlet end temperature and the outlet end temperature of the evaporator.
When the first temperature difference Δ T1 between the inlet and outlet ends of the evaporator is not within a predetermined range [ T10-n, T10+ n ] (including a temperature difference that is too large, greater than T10+ n, and a temperature difference that is too small, less than T10-n), then the temperature control of the refrigeration system is in a fluctuating state. At this time, the PID controller may perform PID calculation based on the difference between the first temperature difference Δ T1 and the first target temperature difference value T10, and output a corresponding PID output quantity. By continuously adjusting the PID output, the temperature control of the refrigeration system reaches a steady state until a first temperature difference Δ T1 between the inlet and outlet ends of the evaporator is within a predetermined range [ T10-n, T10+ n ]. And when the state of T10-n < delta T1< T10+ n is finally reached, the PID controller carries out PID calculation based on the difference value of the first temperature difference delta T1 and the first target temperature difference value T10 to output the PID output quantity which is kept unchanged.
Step S20: comparing a second temperature difference Δ T2, which is obtained based on the evaporation temperature of the refrigerant and the set point temperature, with a second target temperature difference value T20; if the delta T2 is greater than T20+ m, the PID controller which performs PID calculation based on the second temperature difference delta T2 and the second target temperature difference T20 reduces the output quantity; if the delta T2 is less than T20-m, the PID controller which carries out PID calculation based on the second temperature difference delta T2 and the second target temperature difference T20 increases the output quantity; and continuously adjusting the output to obtain M groups of second temperature differences delta T2 until T20-M < delta T2< T20+ M, and keeping the output unchanged.
In this embodiment, the evaporation temperature of the refrigerant may be the temperature at the inlet end of the compressor. Therefore, the evaporation temperature of the refrigerant can be directly measured by the compressor temperature acquisition module. The compressor temperature acquisition module can be a temperature acquisition element and can acquire the inlet end temperature of the compressor in real time, namely the evaporation temperature of the refrigerant. A second temperature differential deltat 2 is derived based on the collected inlet end temperature of the compressor and the setpoint temperature.
Alternatively, the evaporation temperature of the refrigerant may be converted by the evaporation pressure. Specifically, the pressure value at the inlet end of the compressor can be acquired in real time through a return air pressure acquisition module (such as a pressure sensor), and the return air end temperature can be converted based on the one-to-one correspondence relationship between the pressure and the temperature of the saturated steam, and is equal to the evaporation temperature of the refrigerant. Based on the temperature of the air return end and the set value temperature, a second temperature difference Δ T2 can be obtained.
In this embodiment, the second target temperature difference value T20 and the value m may be set according to actual conditions, which is not limited in this embodiment of the present invention, for example, the second target temperature difference value T20 may be 20 ℃ and m may be 3 ℃. The PID calculation is performed based on the difference between the second temperature difference Δ T2 and the second target temperature difference value T20 to solve the problem of overpressure caused by excessive refrigerant evaporation pressure and possible damage to the compressor due to the overpressure.
When the second temperature difference Δ T2 between the evaporation temperature of the refrigerant and the set point temperature is not within a predetermined range [ T20-m, T20+ m ] (including a temperature difference that is too large and larger than T20+ m and a temperature difference that is too small and smaller than T20-m), the evaporation pressure of the refrigerant is in a fluctuating state. At this time, the PID controller may perform PID calculation based on the second temperature difference Δ T2 and the second target temperature difference value T20, and output a corresponding PID output quantity. By continuously adjusting the PID output, the evaporating pressure of the refrigerant reaches a steady state when the second temperature difference delta T2 between the evaporating temperature of the refrigerant and the set point temperature is in a preset range [ T20-m, T20+ m ]. And when the state of T20-m < delta T2< T20+ m is finally reached, the PID controller carries out PID calculation based on the difference value between the second temperature difference delta T2 and the second target temperature difference value T20 to output the PID output quantity which is kept unchanged.
Step S30: the smaller output amount in step S10 and step S20 is selected as the final output amount.
Step S40: the opening of the throttling element is controlled based on the final output quantity.
In this embodiment, the PID output amounts obtained in step S10 and step S20 are compared, and the smaller PID output amount of the two is selected as the final output amount. The PID controller controls the opening of the throttling element based on the final output quantity, and maintains the opening of the throttling element.
In the control method of the refrigeration system according to the embodiment of the present invention, PID calculation is performed based on a difference between a first temperature difference Δ T1 between an inlet end temperature and an outlet end temperature of the evaporator and a first target temperature difference T10, and a corresponding output amount is adjusted and output, so that the first temperature difference Δ T1 between the inlet end temperature and the outlet end temperature of the evaporator is within a suitable range; and adjusting and outputting a corresponding output quantity in combination with the PID calculated by PID based on the second temperature difference Δ T2 and the second target temperature difference value T20. Therefore, the problem that the low-temperature section cannot reach due to overlarge temperature drop is avoided, the situation that the refrigerant evaporation pressure is overlarge due to the overlow expected refrigerating temperature and then the condition that the refrigeration is interrupted by alarming and even the compressor is damaged is avoided, and the temperature of the refrigerating system is intelligently and continuously adjusted.
Based on the same concept, the embodiment of the present invention further provides a control device of a refrigeration system, as described in the following embodiments. Because the principle of solving the problems and the technical effect that can be achieved by the control device are similar to the control method, the implementation of the control device can refer to the implementation of the control method, and repeated details are not repeated. The term "module" used below may be implemented based on software, or based on hardware, or implemented by a combination of software and hardware.
As shown in fig. 3, the control device of the refrigeration system according to the embodiment of the present invention includes:
a first conditioning module 10 for comparing a first temperature differential Δ T1 derived based on an inlet end temperature and an outlet end temperature of the evaporator to a first target temperature differential value T10; if Δ T1> T10+ n, PID controller turndown output is PID calculated based on the first temperature difference Δ T1 and the first target temperature difference T10; if Δ T1< T10-n, PID controller turn up output based on PID calculations of the first temperature difference Δ T1 and the first target temperature difference T10; obtaining N groups of first temperature differences delta T1 by continuously adjusting the output quantity, and keeping the output quantity unchanged until T10-N is less than delta T1 and less than T10+ N;
a second adjusting module 20 for comparing a second temperature difference Δ T2 obtained based on the evaporation temperature of the refrigerant and the set point temperature with a second target temperature difference value T20; if the delta T2 is greater than T20+ m, the PID controller which performs PID calculation based on the second temperature difference delta T2 and the second target temperature difference T20 reduces the output quantity; if the delta T2 is less than T20-m, the PID controller which carries out PID calculation based on the second temperature difference delta T2 and the second target temperature difference T20 increases the output quantity; obtaining M groups of second temperature differences delta T2 by continuously adjusting the output quantity until T20-M is less than delta T2 is less than T20+ M, and keeping the output quantity unchanged;
a selection module 30, configured to select a smaller output obtained by the first and second adjustment modules 10 and 20 as a final output;
and a control module 40 for controlling the opening of the throttling element based on the final output.
The control device of the refrigeration system of the embodiment of the invention corresponds to the control method of the refrigeration system, and has the same technical effect as the control method of the refrigeration system, and the details are not repeated here.
In one embodiment, the control device may further include an evaporator temperature acquisition module, and the temperature acquisition of the inlet end and the outlet end of the evaporator may be realized in real time through the evaporator temperature acquisition module. The evaporator temperature collecting module may include two temperature collecting elements (e.g., temperature sensors, thermocouples, etc.) respectively disposed at the inlet end and the outlet end of the evaporator, for respectively collecting an inlet end temperature t (in) and an outlet end temperature t (out) of the evaporator. Based on the inlet end temperature T (in) and the outlet end temperature T (out) of the evaporator, a first temperature difference Δ T1 is obtained.
In one embodiment, the control device may further include a compressor temperature acquisition module, and the evaporation temperature of the refrigerant may be directly measured by the compressor temperature acquisition module. The compressor temperature acquisition module can be a temperature acquisition element and can acquire the inlet end temperature of the compressor in real time, namely the evaporation temperature of the refrigerant. A second temperature differential deltat 2 is derived based on the collected inlet end temperature of the compressor and the setpoint temperature.
Or, the control device can also comprise a return air pressure acquisition module, and the evaporation temperature of the refrigerant can be converted by the evaporation pressure. Specifically, the pressure value at the inlet end of the compressor can be acquired in real time through a return air pressure acquisition module (such as a pressure sensor), and the return air end temperature can be converted based on the one-to-one correspondence relationship between the pressure and the temperature of the saturated steam, and is equal to the evaporation temperature of the refrigerant. Based on the temperature of the air return end and the set value temperature, a second temperature difference Δ T2 can be obtained.
From the above description of the embodiments, it is clear to those skilled in the art that the present invention can be implemented by software plus necessary general hardware platform. With this understanding in mind, aspects of the present invention may be embodied in software products that are, or constitute part of, a typical configuration of a computing device including one or more processors (CPUs), input/output interfaces, network interfaces, and memory. The computer software product may include instructions for causing a computing device (which may be a personal computer, a server, or a network device, etc.) to perform the methods of the various embodiments or portions of embodiments of the present invention. The computer software product may be stored in a memory, which may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium. Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include transitory computer readable media (transient media), such as modulated data signals and carrier waves.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the electronic device embodiment, since the operation of the processor is substantially similar to that of the method embodiment, the description is simple, and for relevant points, reference may be made to part of the description of the method embodiment.
While the invention has been described in terms of embodiments, those skilled in the art will recognize that there are numerous variations and modifications of the invention without departing from the spirit of the invention, and it is intended that the appended claims cover such variations and modifications as fall within the true spirit of the invention.
Claims (8)
1. A control method of a refrigeration system comprises a throttling element, an evaporator and a compressor which are connected in sequence, wherein the throttling element is controlled by a PID controller; it is characterized by comprising:
step S10: comparing a first temperature differential Δ T1 derived based on an inlet end temperature and an outlet end temperature of the evaporator to a first target temperature differential value T10; if Δ T1> T10+ n, PID controller turndown output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10; a PID controller turn up output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10 if Δ T1< T10-n; obtaining N groups of first temperature differences delta T1 by continuously adjusting the output quantity, and keeping the output quantity unchanged until T10-N is less than delta T1 and less than T10+ N;
step S20: comparing a second temperature difference Δ T2, which is obtained based on the evaporation temperature of the refrigerant and the set point temperature, with a second target temperature difference value T20; if Δ T2> T20+ m, PID controller turndown output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20; a PID controller turn up output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20 if Δ T2< T20-m; obtaining M groups of second temperature differences delta T2 by continuously adjusting the output quantity until T20-M is less than delta T2 is less than T20+ M, and keeping the output quantity unchanged;
step S30: selecting the smaller output quantity in step S10 and step S20 as the final output quantity;
step S40: controlling an opening degree of the throttling element based on the final output quantity.
2. The control method according to claim 1, characterized in that the first temperature difference Δ T1 is obtained by:
the inlet end temperature and the outlet end temperature of the evaporator are collected in real time, and the first temperature difference delta T1 is obtained based on the collected inlet end temperature and outlet end temperature of the evaporator.
3. The control method according to claim 1, characterized in that the second temperature difference Δ T2 is obtained by:
and acquiring the inlet end temperature of the compressor in real time, and acquiring the second temperature difference delta T2 based on the acquired inlet end temperature of the compressor and the set value temperature.
4. The control method according to claim 1, characterized in that the second temperature difference Δ T2 is obtained by:
and acquiring an inlet end pressure value of the compressor in real time, converting the inlet end pressure value of the compressor to obtain a return air end temperature, and acquiring a second temperature difference delta T2 based on the return air end temperature and the set value temperature.
5. A control device of a refrigeration system comprises a throttling element, an evaporator and a compressor which are connected in sequence, wherein the throttling element is controlled by a PID controller; it is characterized by comprising:
a first adjustment module to compare a first temperature differential Δ T1 derived based on an inlet end temperature and an outlet end temperature of the evaporator to a first target temperature differential value T10; if Δ T1> T10+ n, PID controller turndown output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10; a PID controller turn up output based on PID calculations of the first temperature differential Δ T1 and the first target temperature differential value T10 if Δ T1< T10-n; obtaining N groups of first temperature differences delta T1 by continuously adjusting the output quantity, and keeping the output quantity unchanged until T10-N is less than delta T1 and less than T10+ N;
a second adjusting module for comparing a second temperature difference Δ T2 obtained based on the evaporation temperature of the refrigerant and the set point temperature with a second target temperature difference value T20; if Δ T2> T20+ m, PID controller turndown output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20; a PID controller turn up output based on PID calculations of the second temperature difference Δ T2 and the second target temperature difference value T20 if Δ T2< T20-m; obtaining M groups of second temperature differences delta T2 by continuously adjusting the output quantity until T20-M is less than delta T2 is less than T20+ M, and keeping the output quantity unchanged;
the selection module is used for selecting the smaller output quantity obtained by the first regulation module and the second regulation module as the final output quantity;
and the control module is used for controlling the opening of the throttling element based on the final output quantity.
6. The control device of claim 5, further comprising an evaporator temperature acquisition module for acquiring an inlet end temperature and an outlet end temperature of the evaporator in real time; the first temperature difference Δ T1 is obtained based on the collected inlet end temperature and outlet end temperature of the evaporator.
7. The control device of claim 5, further comprising a compressor temperature acquisition module for acquiring an inlet end temperature of the compressor in real time; and obtaining the second temperature difference delta T2 based on the collected inlet end temperature of the compressor and the set point temperature.
8. The control device of claim 5, further comprising a return air pressure acquisition module for acquiring an inlet end pressure value of the compressor in real time, converting the inlet end pressure value of the compressor to obtain a return air end temperature, and obtaining the second temperature difference Δ T2 based on the return air end temperature and the set point temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910667197.7A CN110440491B (en) | 2019-07-23 | 2019-07-23 | Control method and device of refrigeration system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910667197.7A CN110440491B (en) | 2019-07-23 | 2019-07-23 | Control method and device of refrigeration system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110440491A CN110440491A (en) | 2019-11-12 |
| CN110440491B true CN110440491B (en) | 2021-04-20 |
Family
ID=68431207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910667197.7A Active CN110440491B (en) | 2019-07-23 | 2019-07-23 | Control method and device of refrigeration system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110440491B (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5040379A (en) * | 1988-06-21 | 1991-08-20 | Daikin Industries, Ltd. | Temperature controller of liquid cooling system |
| CN103673209B (en) * | 2012-08-31 | 2018-07-31 | 杭州三花研究院有限公司 | The control method and its air-conditioner control system of air-conditioning system |
| CN104457076A (en) * | 2014-12-23 | 2015-03-25 | 天津职业技术师范大学 | Refrigeration method based on PID control electromagnetic valve |
| CN106595141B (en) * | 2016-12-12 | 2019-12-27 | 重庆美的通用制冷设备有限公司 | Control method and device of electronic expansion valve and refrigerating system |
| CN108731324B (en) * | 2018-06-22 | 2020-12-25 | 江苏新安电器有限公司 | Superheat degree controlled electronic expansion valve system |
-
2019
- 2019-07-23 CN CN201910667197.7A patent/CN110440491B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110440491A (en) | 2019-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9182154B2 (en) | Adaptive control of vapor compression system | |
| RU2744305C2 (en) | Control method and device for electronic expansion valve and refrigerating unit | |
| US10352603B2 (en) | Control apparatus for cooling system | |
| CN101311851B (en) | Modified fuzzy control for cooler electronic expansion valve | |
| US7331191B2 (en) | Heating, ventilation and air conditioning (HVAC) system and method using feedback linearization | |
| US10480838B2 (en) | Control device for refrigeration cycle apparatus, and control method for refrigeration cycle apparatus, and refrigeration cycle apparatus | |
| JP2013200115A (en) | Method for operating vapor compression system, method for controlling operation of vapor compression system, and optimization controller for optimizing performance of vapor compression system | |
| CN106440440A (en) | Hot gas bypass control method and system for screw type unit | |
| CN110440491B (en) | Control method and device of refrigeration system | |
| CN110427059B (en) | Temperature and humidity testing method and device for damp-heat test box | |
| CN117270593B (en) | Helium pressure control method, electronic device and readable storage medium | |
| Matsumoto et al. | Numerical analysis of control characteristics of variable refrigerant flow heat-pump systems focusing on the effect of expansion valve and indoor fan | |
| CN107975920B (en) | Expansion valve control method and multi-split system | |
| Price et al. | Optimal tuning of cascaded control architectures for nonlinear HVAC systems | |
| CN114608181B (en) | Control method and device for electronic expansion valve, medium and air source heat pump unit | |
| CN113154789B (en) | Control method and system for parallel double-system refrigerator | |
| WO2015159326A1 (en) | Refrigerating device | |
| CN109612049B (en) | Method and device for controlling output power of compressor | |
| JP7301230B2 (en) | refrigeration cycle equipment | |
| CN110196553B (en) | Control method and device for high-temperature and high-humidity running of test box with dynamic thermal load | |
| CN110546441B (en) | Method for controlling suction pressure based on maximum load cooling entity | |
| CN113739560B (en) | Drying system control method and device and drying system | |
| CN115638526B (en) | Control method and device for expansion valve of air conditioner and air conditioning system | |
| CN115654712B (en) | Multi-connected air conditioner control method and device and multi-connected air conditioner | |
| US20230064936A1 (en) | Method of operating a heat pump system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CB03 | Change of inventor or designer information |
Inventor after: He Yuquan Inventor before: Zhang Bo |
|
| CB03 | Change of inventor or designer information | ||
| CP03 | Change of name, title or address |
Address after: 215300 plants A6, a7, a8 and B10, No. 8, Huacheng Road, Lujia Town, Kunshan City, Suzhou City, Jiangsu Province Patentee after: Jiangsu Tuomiluo High-end Equipment Co.,Ltd. Address before: 215300 No.427 Sanxiang Road, Kunshan Economic and Technological Development Zone, Suzhou City, Jiangsu Province Patentee before: JIANGSU TOLIMO ENVIRONMENT TESTING EQUIPMENT Co.,Ltd. |
|
| CP03 | Change of name, title or address |