CN111765680A - An ice-making system control strategy and system - Google Patents

Abstract

The invention discloses a control strategy and system for an ice making system, which is divided into a standby state, a start state, a running state and a stop state. Ice start subroutine, then mark it as running state and enter, if the ice making stop condition is met, enter; judge whether the ice making stop condition is met; interpret whether it is blocked; judge whether the crystal promoting operation condition is met; execute the crystal promoting subroutine, and then enter, If the blockage condition is met, enter; execute the defrosting subroutine, then enter; if the ice making stop condition is met, enter; execute the ice making stop subroutine, and then mark the standby state and enter. The invention can effectively reduce the ice blocking phenomenon of the ice-making circuit during the ice-making operation, shorten the ice-making time and reduce the energy consumption of the equipment, thereby realizing the safe, continuous and efficient operation of the ice-making system on the basis of satisfying the cooling demand of users.

Description

An ice-making system control strategy and system

technical field

The invention relates to the technical field of ice making, in particular to an ice making system control strategy and system.

Background technique

Centralized central air conditioning is an indispensable part of large urban buildings. With the increasing power consumption of air conditioning systems in recent years, energy saving has become a key concern of the air conditioning industry. The cold storage system is adopted, which can reduce the energy consumption of the air conditioning and refrigeration units during the peak period of power consumption by storing cold during the low power period at night and releasing the cold during the peak power period during the day. The peak-valley electricity price difference saves the overall operating cost of the air conditioner and brings economic benefits. Among them, the dynamic ice slurry production technology solves the shortcomings of the traditional cold storage system such as large space and low efficiency by means of flowing ice, and has become the mainstream development direction of the current cold storage technology.

The operating conditions of the dynamic ice slurry making system are complex, and the automation requirements are high, which requires the system to realize automatic judgment, such as ice making startup based on user settings, system shutdown based on faults or completion of ice making requirements, etc. At the same time, the system operation process includes: In the working modes such as clogging judgment, crystallization promotion, and thawing, different devices need to be turned on according to the real-time status of the system to realize the corresponding functions, so as to ensure the safe, continuous and efficient operation of the system.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the present invention provides an ice making system control strategy and system to improve the stability and reliability of the system operation.

For achieving the above object, technical scheme of the present invention is as follows:

An ice-making system control strategy, the operating conditions of the ice-making system at least include a standby state, a start-up state, a running state and a shutdown state, and the ice-making system at least includes a compressor, an ice-making pump, a coolant pump, and a condensing fan , crystal promoter and four-way valve, the control strategy includes the following steps:

S1: Determine whether the ice making system is in the standby state and meet the ice making start conditions at the same time, if so, mark it as running state and execute S2, if not, execute S1 cyclically;

S2: Execute the ice making start subroutine, after the ice making start subroutine is executed, mark it as running state and execute S3, if the ice making stop condition is met during the execution of the ice making start subroutine, mark it as the shutdown state and execute S8;

S3: determine whether the ice making system meets the ice making stop condition, if so, mark it as a shutdown state and execute S8, if not, execute S4;

S4: determine whether the ice making system is blocked, if not, execute S5, and if it is blocked, execute S7;

S5: judge whether the ice making system satisfies the crystal promoting operation conditions, if so, execute S6, if not, execute S3;

S6: Execute the crystallization promotion subroutine, after the crystallization promotion subroutine is executed, execute S3, and if the ice making system is blocked during the execution of the crystallization promotion subroutine, execute S7;

S7: Execute the thawing subroutine, after the thawing subroutine is executed, execute S3, if the ice making system meets the ice making stop condition during the execution of the thawing subroutine, mark it as a shutdown state and execute S8;

S8: Execute the ice-making stop subroutine, and after the ice-making stop subroutine is completed, mark it as a standby state and return to S1.

In the above ice making system control strategy, further, the standby state is a state in which all devices of the ice making system are powered on and waiting for a trigger signal; the startup state is each device of the ice making system In the process of starting according to the set order, the ice making starting subroutine is that the refrigerant pump, the condensing fan, the ice making pump, and the compressor start successively according to the set order and time interval.

In the ice-making system control strategy as described above, further, the operating state is a process in which the ice-making system performs ice-making operation, and the shutdown state is that each device of the ice-making system is shut down in a set order. process, wherein the operating state includes judging clogging, judging crystallization-promoting operating conditions, executing crystallization-promoting subroutines, and executing thawing subroutines; The setting sequence and time interval of the ice pump, crystal promoter and four-way valve are closed successively.

In the above-mentioned ice making system control strategy, further, the ice making starting condition is that the ice making starting trigger signal is accepted when the current ice making amount of the ice making system is lower than the set value.

In the above-mentioned ice making system control strategy, further, the method for judging whether the ice making system is blocked is: judged by the flow rate and pressure of the outlet of the refrigeration pump of the ice making system, if the flow rate and pressure are greater than the set value, The ice storage system is not blocked; if the flow or pressure is less than the set value, the ice making system is blocked at this time.

In the ice-making system control strategy as described above, further, the crystallization-promoting operating condition is that the temperature of the supercooled water in the circuit where the ice-making pump of the ice-making system is located after being exchanged by the heat exchange plate is lower than a certain set value T _set , and the set value T _set is in the set interval T _set ∈(T _min , T _max ).

In the above-mentioned ice making system control strategy, further, the ice making stop condition is to obtain a trigger signal for stopping ice making, or the execution times of the defrosting subroutine reach a set upper limit.

In the control strategy of the ice-making system as described above, further, the crystal promoting subroutine is to enable the crystal promoting device to start and run according to the set time period under the condition that the crystal promoting operation condition is satisfied.

The ice-making system control strategy as described above, further, the defrosting subroutine is to first close the ice-making pump, then open the four-way valve and open the four-way valve to run according to the set time period, and then close the four-way valve and reopen it. Ice pump.

An ice-making system, which utilizes the ice-making system control strategy described above, the system comprising a compressor, an ice-making pump, a refrigerant pump, an evaporating plate, a condensing fan, a crystallizer, and a four-way valve;

The high-pressure outlet of the compressor is connected to the four-way valve inlet and the low-pressure inlet of the compressor is connected to the four-way valve outlet, so as to realize gas compression;

One end of the condensing fan and one end of the evaporating plate are connected through an expansion valve, the other end of the condensing fan is connected to the normal opening of the four-way valve, and the other end of the evaporating plate is connected to the four-way valve. The normally closed port of the through valve, wherein the on-off of the four-way valve is used to convert the normally open port and the normally closed port to change the gas flow direction to realize the switching of working conditions. When the power is turned on, it is the heating condition;

The refrigerant carrier pump is connected with the evaporating plate and the subcooling plate through the pipeline to form a refrigerant circuit, so as to realize the flow of the refrigerant;

The ice making pump is connected with the crystal promoter and the subcooling plate through pipes to form an ice making circuit, so as to realize the flow of ice slurry and water.

Compared with the prior art, the present invention has the beneficial effect that: according to the various operating conditions of the ice making system, it is divided into a standby state, a startup state, a running state and a shutdown state, and through reasonable judgment conditions and jumping processes , Combined with different working modes and different functions of the corresponding equipment, an automatic operation control strategy of the ice making system is designed, which can effectively reduce the ice blocking phenomenon of the ice making circuit during the ice making operation, shorten the ice making time and reduce the energy consumption of the equipment , so as to realize the safe, continuous and efficient operation of the ice-making system on the basis of meeting the cooling needs of users.

Description of drawings

FIG. 1 is a flow chart of the ice making system control strategy of the present invention.

Detailed ways

The content of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Example:

As shown in Figure 1, an ice-making system control strategy includes the following steps:

a. If the ice-making system is in a standby state and the conditions for starting ice-making are met, mark it as a start-up state and go to step b, otherwise, perform step a in a loop; wherein, the standby state is that all the devices of the ice-making system are in the connected state. The state of being powered on and waiting for a trigger signal; the ice making start condition is that the ice making system accepts the trigger signal for starting ice making when the current ice making amount of the ice making system is lower than the set value; the starting state is the ice making system of each device is in the process of starting up in a set order.

b. Execute the ice-making start subroutine. After the ice-making start-up subroutine is executed, mark it as a running state and enter step c; if the ice making stop condition is met during the period, mark it as a stop state and enter step h; the ice making start The subroutine is that the refrigerant pump, the condensing fan, the ice making pump and the compressor are started successively in the set order and time interval; the ice making stop condition is to obtain the trigger signal for stopping the ice making, or the execution times of the defrosting subroutine reach the set time. The operating state is a process in which the ice-making system performs ice-making operation; and the shutdown state is a process in which each device of the ice-making system is shut down in a set order.

c. Determine whether the ice-making system meets the ice-making stop condition, if so, mark it as a shutdown state and go to step h; otherwise, go to step d; the ice-making stop condition is to obtain a trigger signal for ice-making stop, or a thawing subroutine The number of executions reaches a set upper limit value; the shutdown state is a process in which each device of the ice making system is shut down in a set order.

d. Judging whether the ice making system is blocked, if not, go to step e, otherwise, go to step g; the method for judging whether the ice making system is blocked is: Judging by the flow and pressure of the outlet of the refrigeration pump of the ice making system , if the flow and pressure are greater than the set value, the ice storage system is not blocked; if the flow or pressure is less than the set value, the ice making system is blocked at this time.

e. Determine whether the ice-making system meets the crystal-promoting operation conditions, and if so, go to step f; otherwise, go to step c; The temperature after the plate replacement is lower than a certain set value T _set , and the set value T _set is in the set interval T _set ∈(T _min , T _max ).

f. Execute the crystal promoting subroutine. After the crystal promoting subroutine is executed, go to step c; if it is judged that the ice making system is blocked during the period, go to step g; Turn on and run according to the set time; the method of judging whether the ice making system is blocked is: Judging by the flow and pressure of the outlet of the refrigeration pump of the ice making system, if the flow and pressure are greater than the set value, the ice storage system is not blocked ; If the flow or pressure is less than the set value, the ice making system is blocked at this time.

g. Execute the thawing subroutine, and after executing the thawing subroutine, go to step c; if it is judged that the ice making system meets the ice making stop condition during the period, mark it as a shutdown state and enter step h; the thawing subroutine is to first turn off the ice making pump, then open the four-way valve and open the four-way valve to run according to the set time period, then close the four-way valve and restart the ice-making pump; the ice-making stop condition is to obtain the trigger signal of ice-making stop, or the defrosting subroutine The number of executions reaches a set upper limit value; the shutdown state is a process in which each device of the ice making system is shut down in a set order.

h. Execute the ice-making stop subroutine. After the ice-making stop subroutine is executed, mark it as a standby state and enter step a. The ice-making stop subroutine is that the compressor, the condensing fan, the refrigerant pump, the ice-making pump, the crystallizer, and the four-way valve are set in sequence and the time interval is closed successively; the standby state is the ice-making system. All devices are powered on and waiting for a trigger signal.

In this embodiment, the ice-making system control strategy can be implemented in a conventional ice-making machine. A conventional ice-making machine generally includes a compressor, an ice-making pump, a refrigerant pump, a condensing fan, a crystallizer, and a four-way valve. An ice-making system provided by another solution of the present invention can also be used. The working process of the method is as follows: turn on the power of the ice-making system, and all devices are powered on and kept in a standby state; When the ice is completely melted, turn on the ice-making automatic operation control switch to obtain a trigger signal for ice-making to start; at this time, mark it as the start-up state and perform step b;

Set the device-on interval to 30 seconds, and the ice-making system turns on the refrigerant pump, the condensing fan, the ice-making pump, and the compressor in sequence; then mark it as a running state and perform step c.

Set the maximum execution times of the defrosting subroutine to 1, and set the trigger signal of ice making stop to come from compressor overload, ice making pump failure, refrigerant pump failure, condensing fan failure or the ice making automatic operation control switch is closed. Then, when the above conditions are not met, the control flow runs cyclically between step d and step g.

Set the flow rate at the outlet of the refrigeration pump to 4m ³ /h, and monitor the flow rate at the outlet of the refrigeration pump in real time; if the flow rate is greater than or equal to 4m ³ /h, it is judged that the system is not blocked, and then go to step e; if the flow rate is less than 4m ³ /h, judge The system is blocked, go to step g.

If it is detected that the current flow rate is 4.5m ³ /h, it is determined that the system is not blocked, and the process goes to step e. Set T _set to -0.4 °C, T _min to -1.6 °C, T _max to 1 °C, and set the crystallization promotion time to 500 seconds. If the temperature is -0.5°C at this time, the crystallizer is turned on for crystallizing. After executing the subroutine for promoting crystallization, re-enter step c for cyclic operation.

If it is detected that the current flow rate is 3.5m ³ /h, it is judged that the system is blocked, and the process goes to step g. Set the defrosting time to 400 seconds. At this time, firstly turn off the ice making pump, then open the four-way valve and defrost for 400 seconds; then close the four-way valve and turn on the ice making pump again.

Since the maximum number of execution times of the defrosting subroutine is set to be 1, the ice making stop condition is satisfied at this time. Set the interval time for equipment shutdown to 10 seconds, and the ice making system will turn off the compressor, condensing fan, refrigerant pump, and ice making pump in sequence. After executing the ice-making stop subroutine, mark the ice-making system as the standby state, reset the ice-making automatic operation control switch to the off state, and re-enter step a to wait for the next start-up operation.

In addition, the present invention also provides an ice-making system, which operates using the above-described ice-making system control strategy, the system includes a compressor, an ice-making pump, a refrigerant pump, an evaporating plate, a condensing fan, a crystallizer, and a spool. valve; the high-pressure outlet of the compressor is connected to the four-way valve inlet and the low-pressure inlet of the compressor is connected to the four-way valve outlet to realize gas compression; one end of the condensing fan and the other end of the evaporating plate are connected through the expansion valve, and the other end of the condensing fan is connected To the normally open port of the four-way valve, the other end of the evaporation plate is connected to the normally closed port of the four-way valve. When the four-way valve is de-energized, it is in cooling mode, and when it is energized, it is in heating mode; the refrigerant pump is connected with the evaporating plate and the sub-cooling plate through the pipeline to form a refrigerant circuit, so as to realize the refrigerant circuit. The ice-making pump is connected with the crystallizer and the subcooling plate through the pipeline to form an ice-making circuit to realize the flow of ice slurry and water. The condensing fan is used for gas cooling, the evaporation plate is used for gas evaporation, and the crystallizer uses For generating ice crystals, the ice making system provided herein can be used to implement the ice making system control strategy described above.

According to the various operating conditions of the ice-making system, the invention divides it into a standby state, a start-up state, a running state, and a stop state. Through reasonable judgment conditions and jumping procedures, the device can be correspondingly opened in combination with different working modes and different functions. , an automatic operation control strategy of the ice-making system is designed, which can effectively reduce the ice-blocking phenomenon of the ice-making circuit during the ice-making operation, shorten the ice-making time and reduce the energy consumption of the equipment. Realize the safe, continuous and efficient operation of the ice making system.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those of ordinary skill in the art to understand the content of the present invention and implement them accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the essence of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. An ice-making system control strategy, characterized in that the operating conditions of the ice-making system at least include a standby state, a start-up state, a running state and a shutdown state, and the ice-making system at least includes a compressor, an ice-making pump, a load Refrigerant pump, condensing fan, crystal promoter and four-way valve, the control strategy includes the following steps: S1: Determine whether the ice making system is in the standby state and meet the ice making start conditions at the same time, if so, mark it as running state and execute S2, if not, execute S1 cyclically; S2: Execute the ice making start subroutine, after the ice making start subroutine is executed, mark it as running state and execute S3, if the ice making stop condition is met during the execution of the ice making start subroutine, mark it as the shutdown state and execute S8; S3: determine whether the ice making system meets the ice making stop condition, if so, mark it as a shutdown state and execute S8, if not, execute S4; S4: determine whether the ice making system is blocked, if not, execute S5, and if it is blocked, execute S7; S5: judge whether the ice making system satisfies the crystal promoting operation conditions, if so, execute S6, if not, execute S3; S6: Execute the crystallization promotion subroutine, after the crystallization promotion subroutine is executed, execute S3, and if the ice making system is blocked during the execution of the crystallization promotion subroutine, execute S7; S7: Execute the thawing subroutine, after the thawing subroutine is executed, execute S3, if the ice making system meets the ice making stop condition during the execution of the thawing subroutine, mark it as a shutdown state and execute S8; S8: Execute the ice-making stop subroutine, and after the ice-making stop subroutine is completed, mark it as a standby state and return to S1. 2 . The ice-making system control strategy according to claim 1 , wherein the standby state is a state in which all devices of the ice-making system are powered on and waiting for a trigger signal; the start-up state is the Each device of the ice-making system is in the process of starting up in a set order, and the ice-making start-up subroutine is that the refrigerant pump, the condensing fan, the ice making pump, and the compressor are started successively in the set order and time interval. 3 . The ice making system control strategy according to claim 1 , wherein the operating state is a process in which the ice making system performs ice making operation, and the shutdown state is that each device of the ice making system is in a state. The process of shutting down according to the set order, wherein, the operating state includes judging the blockage, judging the operating conditions of promoting crystallization, executing the subroutine of promoting crystallization and executing the subroutine of defrosting; the subroutine of stopping ice making is compressor, condenser fan, The set sequence and time interval of the refrigerant pump, ice making pump, crystal promoter and four-way valve are closed successively. 4 . The ice making system control strategy according to claim 1 , wherein the ice making starting condition is that the ice making starting trigger signal is accepted when the current ice making amount of the ice making system is lower than a set value. 5 . 5. The ice-making system control strategy according to claim 1, wherein the method for judging whether the ice-making system is blocked is: judging by the flow and pressure of the outlet of the refrigeration pump of the ice-making system. If the pressure is greater than the set value, the ice storage system is not blocked; if the flow or pressure is less than the set value, the ice making system is blocked at this time. 6 . The ice making system control strategy according to claim 1 , wherein the crystal promoting operation condition is that the temperature of the supercooled water in the circuit where the ice making pump of the ice making system is located after being exchanged by the heat exchange plate is lower than A certain set value T _set , and the set value T _set is in the set interval T _set ∈ (T _min , T _max ). 7 . The ice making system control strategy according to claim 1 , wherein the ice making stop condition is to obtain a trigger signal for stopping ice making, or the execution times of the thawing subroutine reach a set upper limit. 8 . 8 . The ice making system control strategy according to claim 1 , wherein the crystal promoting subroutine is that the crystal promoting device is turned on and running according to a set time period under the condition that the crystal promoting operation condition is satisfied. 9 . 9 . The ice-making system control strategy according to claim 1 , wherein the defrosting subroutine is to first close the ice-making pump, then open the four-way valve and open the four-way valve to operate according to a set duration, and then close 4-way valve and turn the ice pump back on. 10. An ice making system using the ice making system control strategy according to any one of claims 1 to 9, wherein the system comprises a compressor, an ice making pump, a refrigerant pump, an evaporation plate, Condensing fan, crystal promoter and four-way valve; The high-pressure outlet of the compressor is connected to the four-way valve inlet and the low-pressure inlet of the compressor is connected to the four-way valve outlet, so as to realize gas compression; One end of the condensing fan and one end of the evaporating plate are connected through an expansion valve, the other end of the condensing fan is connected to the normal opening of the four-way valve, and the other end of the evaporating plate is connected to the four-way valve. The normally closed port of the through valve, wherein the on-off of the four-way valve is used to convert the normally open port and the normally closed port to change the gas flow direction to realize the switching of working conditions. When the power is turned on, it is the heating condition; The refrigerant carrier pump is connected with the evaporating plate and the subcooling plate through the pipeline to form a refrigerant circuit, so as to realize the flow of the refrigerant; The ice making pump is connected with the crystal promoter and the subcooling plate through pipes to form an ice making circuit, so as to realize the flow of ice slurry and water.

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