KR101032106B1 - Method of operating chiller system for improving energy efficiency and subsidiary equipment for the method - Google Patents

Abstract

A method of operating a refrigerator system in which a plurality of refrigerators are connected in parallel includes collecting an instantaneous freezing amount of each freezer into a database, and comparing the real-time operating number of the freezer with the real-time required operating number from the instant freezing amount collected in the database. And presenting a comparison result according to the required number of real-time operations. By calculating the required number of real-time operation of the refrigerator and comparing it with the actual number of operation, we propose an operation method that can maximize the load ratio.

Refrigerator, load rate, energy saving

Description

Operation Method and Operational Aids of Refrigerator System for Energy Saving {METHOD OF OPERATING CHILLER SYSTEM FOR IMPROVING ENERGY EFFICIENCY AND SUBSIDIARY EQUIPMENT FOR THE METHOD}

The present invention relates to a method of operating a refrigerator system, and more particularly, to a system operating method and an auxiliary device for implementing the operating method that can increase the energy efficiency in a system including a plurality of refrigerators.

In addition to operating the work line for the industrial plant to operate, the conditions necessary for the operation of the work line or the smooth operation of the surrounding equipment must also be met. For example, not only stable power should be provided, but also compressed air must be supplied continuously to create an air cylinder or a certain air pressure, and boiler facilities must be operated continuously if the industrial facility requires steam. In addition, in order to control the temperature of various equipment, the refrigerator equipment may need to be continuously operated.

The facilities that are essential for the smooth operation of industrial facilities are called utility facilities, and utility facilities include air compressors, refrigerators, and boilers. In general, utility facilities operating in industrial facilities are of high capacity, with fewer than a few operating units or as many as tens of units connected in parallel to provide the conditions necessary for the industrial plant to operate.

In addition, when designing industrial facilities, it is common to design utility facilities beyond the expected capacity of the plant in the short term to facilitate future expansion. As a result, each industrial facility generally has utility facilities that are larger than they currently need, and these utility facilities are either fully operational in meaningless or indiscriminately operating without certain principles.

The present invention provides a method of operating a refrigeration system that is capable of controlling the number of operations of the refrigerator most efficiently in operating an associated refrigerator utility system comprising a plurality of refrigerators.

The present invention provides a method of operating a refrigerator system capable of diagnosing individual efficiency of the refrigerator in operating a refrigerator utility system including a plurality of refrigerators and providing optimal operating conditions according to the load ratio of the refrigerator.

The present invention provides a method of operating a refrigerator system that can monitor a refrigerator individually in operating a refrigerator utility system including a plurality of refrigerators, select a refrigerator requiring repair and management, and provide an operating condition for the refrigerator maintenance and management. To provide.

According to one exemplary embodiment of the present invention for achieving the above object of the present invention, a method for operating a refrigerator system in which a plurality of refrigerators are connected in parallel, collecting the instantaneous freezing amount of each refrigerator in a database; Comparing the real-time running number of the freezer with the real-time required running number from the instantaneous freezing amount collected in the database; And presenting a comparison result according to the required number of real-time operations.

Conventionally, a plurality of refrigerators are simply connected to the central control unit of the system and only report the amount of freezing, etc., while the operation method according to the present invention collects and collects data reported from or to the central control unit. The information can be used to suggest the optimal operating conditions. Specifically, in the case of the refrigerator, the instantaneous freezing amount can be collected in a unit of time or continuously from the temperature sensor mounted on the input side and the output side and the flow rate sensor mounted on the output side, using all or part of the collected information. The load rate or efficiency of each refrigerator can be measured.

The operation method according to the present invention can calculate the number of real-time operation required or the real-time operation of the refrigerator based on the concept of load rate or efficiency, etc. Can be determined.

If the freezer is operated excessively or differently than necessary, information may be given to reduce the number of operations of the freezer or to stop the operation of a particular freezer. The information on the increase and decrease of the operation of the refrigerator can be directly transmitted to the central control unit and used to automatically control the system, but it can also be used to simply present the system control direction to minimize the burden of system change.

According to another exemplary embodiment of the present invention, the operation assistance equipment which presents a method of operating the refrigerator system by connecting to a network of refrigerator systems in which a plurality of refrigerators are connected in parallel, the instantaneous freezing amount of each refrigerator from the network A data storage unit collecting the data in a database; A calculation unit for comparing the real-time operating number of the refrigerator with the real-time required operating number from the instant freezing amount collected in the data storage unit; And an information transfer unit for presenting a comparison result according to the required number of real-time operations.

After comparing the number of real-time operation and the number of real-time operation required, the information transmission unit can send the comparison result according to the real-time operation operation required directly to the central control unit of the system through the network, but otherwise, it simply provides the necessary information through its own display unit. It can also function.

The present invention can provide information that can adjust the number of operation of the refrigerator most efficiently in operating the refrigerator utility system, otherwise it is possible to select a refrigerator for the most efficient operation.

In addition, the present invention uses the concept of the load ratio, it is possible to provide information for controlling the operation of the individual refrigerators in real time to keep the number of operation required and the actual operation number as high as possible to maintain the load ratio as high as possible.

By diagnosing the individual efficiency of the freezer and providing the best operating conditions according to the load rate of the freezer, selecting the freezer that needs to be repaired and maintained, and stopping the freezer that needs to be repaired and managed. Can make it possible to stand up.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. For reference, in the present description, the same numbers refer to substantially the same elements, and may be described by referring to the contents described in the other drawings under these rules, and the contents determined to be obvious to those skilled in the art or repeated may be omitted.

1 is a view showing a driving assistance device for presenting a method of operating a refrigerator system according to an embodiment of the present invention.

Referring to FIG. 1, a refrigerator system is provided, and a plurality of refrigerators 120, 130, and 140 are connected in parallel to the refrigerator system. The plurality of refrigerators 120, 130, 140 may be connected to one or more pipelines to provide chilled water or coolant adjusted to a specific temperature.

The temperature and flow rate of the cold water supplied by the pipeline can be controlled by the central control unit 110, it is provided to provide a constant temperature of cold water through the automatic valve or manual valve operation depending on the use.

At the same time, each refrigerator 120, 130, 140 is equipped with flow sensors 124, 134, 144 and temperature sensors 128, 138, 148 on the output side and pumps 121, 131 on the input side. 141, and temperature sensors 123, 133, and 143 are mounted. Motors 122, 132, and 142 of the refrigerators 120, 130, and 140 are equipped with power sensors 126, 136, and 146 for detecting whether the refrigerators 120, 130, and 140 operate or operate. The flow sensor 124, 134, 144, input side temperature sensor 123, 133, 143, output side temperature sensor 128, 138, 148, power sensor 126, 136, 146, etc. It can be installed separately to implement the operation method according to the sensor or installed to monitor the operation of the existing refrigerator.

The cold water or medium passing through the refrigeration pipe by the operation of each of the pumps 121, 131, and 141 is provided to each of the refrigerators 120, 130, and 140, and the temperature is lowered by the refrigerators 120, 130, and 140. The cold water is again provided to the cold water supply header 160 through a pipe, and cold water may be provided from the cold water supply header 160 where cold water is required in an industrial facility.

The cold water or the medium passing through the industrial facility is returned to the cold water return header 170 in a state where the temperature is raised, and the returned cold water is again returned to the freezers 120, 130, and 140 through the pumps 121, 131, and 141. Is provided. The cold water supply header 160 is equipped with a sensor for measuring temperature and pressure, and the cold water return header 170 is equipped with a sensor for measuring temperature and pressure.

The flow sensor 124, 134, 144 of the refrigerator, the input side temperature sensors 123, 133, 143, the output side temperature sensors 128, 138, 148 and the power sensors 126, 136, 146 are networked. It is connected to and separately, the network may transmit the information collected from the sensor to the central control unit 110. The central control unit 110 may display the collected information in a control room or the like, and may control the operation of a specific device.

As shown, the driving assistance device 200 of the refrigerator system according to the present embodiment includes a calculation unit 210, a data storage unit 220 and the information transmission unit 230. The driving assistance device 200 is in a state connected to the refrigerator system, and the data storage unit 220 collects the instantaneous freezing amount of each of the refrigerators 120, 130 and 140 from the network in its own or separate database, The calculating unit 210 may compare the real-time operation number of the refrigerator and the real-time required operation number of the freezer from the data of the instantaneous freezing amount collected in the data storage unit 220. In this case, in addition to the instantaneous freezing amount of the freezer may also collect the instantaneous power, instantaneous efficiency, instantaneous load rate, etc., the operation unit 210 to compare the instantaneous freezing amount, instantaneous power, instantaneous power to compare the real-time operation number and the required operation number of the freezer. Load factor etc. can also be used together.

If the required number of real-time operation is smaller than the number of real-time operation, the driving assistance device 200 can express only the number of units without specific or no need to stop the operation, and in some cases immediately generate information transmission or signal for automatic control You can do it.

Here, the refrigerators 120, 130 and 140 include an automatic control circuit that can independently control the operating conditions, and can be automatically adjusted to a small load rate independently when there is little flow rate on the output side of the cold water.

The information transmitter 230 may transmit the comparison result according to the required number of real-time operations in various ways. For example, the network can provide the necessary information directly to the refrigeration system's central control unit. Otherwise, it can provide the result of comparison of the required number of real-time operation within the equipment through its own display without any external command. It may be.

Hereinafter, the concept of the invention according to the present invention will be described.

Relationship between Load Rate and Efficiency of Refrigerator System

In a refrigerator system in which a plurality of refrigerators are connected in parallel, the refrigerators are operated at the same time, and may not always operate at the rated capacity, and the amount of refrigeration provided may change from time to time as the external environmental conditions change.

For example, if several chillers are running, reducing the amount of cold water used in a facility using a chiller utility may reduce the instantaneous freezing of the chiller, and in some cases there may be a chiller that is not actually running.

In fact, it was found that even if the instantaneous freezing amount of the cold water output from the freezer in the freezer system is reduced, the power consumption is not reduced by the decreasing amount of freezing. To understand this more easily, the load ratio and the efficiency of the system can be defined as follows. Can be. That is, the flow rate is Q (m ³ / Hr), the freezing quantity or freezing tone is C (RT), the power consumption is W (kW), the cold water supply temperature is T _s (℃), and the cold water return temperature is T _r (℃). , The cold water density can be defined as ρ (kg / m ³ ), the cold water specific heat as C _p (kcal / kg · ℃), and the efficiency is η (RT / kWh). Instantaneous power consumption). The instant freezing amount or the instant freezing tone of the freezer may be defined as C _u with reference to Equation 1 below. For reference, Q _u is the instantaneous flow rate of the individual refrigerators.

In addition, the load ratio can be defined as R (%) (instant freezing tone of the refrigerator) / (static capacity of the refrigerator).

Where R _u is the instantaneous load rate of the individual refrigerators and R _s is the instantaneous load rate of the refrigerator system. And C _u is the instant freezing tone of the individual freezer, u is the individual freezer number, C _{u (d)} is the nominal freezing tone of the individual freezer, C _s is the instant freezing ton of the freezer system, and C is the sum of the individual freezers and C _{s (d)} can be defined as the rated refrigeration tone of the refrigeration system.

2 is a graph for explaining the relationship between the load ratio and the efficiency of the refrigerator, FIG. 3 is a graph for explaining a change in the load ratio of the freezer during operation of the refrigerator system, and FIG. 4 illustrates a change in efficiency of the freezer during operation of the refrigerator system. It is a graph for this.

Referring to Figure 2, it can be seen that the refrigerator has a feature that the efficiency increases as the load ratio generally increases. Therefore, operating a high load factor in operating a multiple refrigeration system can be one of the energy saving measures. In order to operate the load ratio high, it is necessary to optimally adjust the number of operating units of the refrigerator to correspond to the amount of freezing required on the load side (consumer side).

3 actually shows the change in load rate over time. As shown, the load rate may repeat increasing and decreasing over time. As shown in FIG. 2, when the load ratio is high, the efficiency increases, but when the load ratio is low, the efficiency may also decrease. Referring to FIG. 4, it can be seen that the change in efficiency with time is also changed in a pattern substantially similar to the change in load factor of FIG. 3.

Real time need operation log output

Determining whether or not the plurality of refrigerators are operating at a high load rate can also be seen in the process of calculating the real-time required number of operations N _{s (d)} . According to this embodiment, the real-time required number of operations N _{s (d)} is the instantaneous freezing tone (C _s ) of the freezer system measured in real time, the rated freezing tone (C _{s (d)} ) of the freezer system measured in real time and the It can be calculated by comparing the real time running number (N _s ) of the refrigerator.

Here, the Roundup () function may be defined as a function for obtaining a natural number of values rounded off the parenthesis below the decimal point, and the real-time required number of operations N _{s (d)} may be calculated through the above equation.

The real-time oversupply operation number (N _e ) can be defined as the value obtained by subtracting the real-time required operation number from the real-time operation number (= real-time operation number-real-time operation required number). When N _e = 0, it can be seen that the freezer system is operating normally. However, when N _e ≥ 1, it may be defined that the freezer is excessively operated in the freezer system, and when N _e ≤ -1, it may be defined that the freezer is insufficiently operated in the freezer system.

Information delivery by real-time required number of operations

According to the comparison result of the real-time over-sufficient operation number N _e , the driving assistance apparatus according to the present embodiment may provide various information.

For example, if it is determined that the refrigerator is excessively running (N _e ≥ 1), it is preferable to stop the operation when the rated refrigeration tone is smaller if the rated refrigeration tones of all the freezers are not the same. This is because an improper shutdown of a refrigerator with a large rated refrigeration tone may result in an unexpected cold water shortage in the overall system. However, if the rated refrigeration tones of the refrigerators in operation are all the same, it is desirable to stop the operation from the one with the lowest efficiency. For reference, the efficiency of the freezer may be defined as the instant freezing tone for the instantaneous power consumption supplied to the freezer (C / W).

On the contrary, when it is judged that the refrigerator is insufficiently operated (N _e ≤ -1), it is preferable to start the operation when the rated refrigeration ton is small unless all of the rated refrigeration tones of the freezer in operation are the same. This is because the load factor can be prevented from dropping significantly by operating the one with the lowest rated freezing tone. On the other hand, if the rated refrigeration tones of the refrigerators in operation are all the same, it is preferable to start the operation from the one with the highest efficiency.

FIG. 5 is a flowchart illustrating a procedure and a method for individually monitoring a refrigerator in operating a refrigerator utility system including a plurality of refrigerators to provide an optimal operating condition for energy saving.

6 is a graph showing a change in the relationship between the efficiency and the load factor according to an embodiment of the present invention, Figure 7 is a graph showing the change in load rate with time, Figure 8 shows a change in efficiency over time 9 is a graph comparing energy consumption.

Referring to FIG. 6, assuming that the refrigerator system is monitored by using concepts such as load rate R, efficiency, real-time required number of operations, and the system is controlled using information transmitted through the information transmitting unit, the load rate is approximately. It can be operated at 80% or above the desired load rate, thus allowing the refrigeration system to operate while maintaining efficiency above a certain efficiency.

Referring to FIG. 7, the load ratio with time fluctuated by a large deviation before the operation method of the present invention is applied. However, after the application of the operation method of the present invention, the load ratio is insignificant and maintained almost constant.

Accordingly, as shown in FIG. 8, the efficiency can also be maintained at the highest load factor, and as compared with before improvement, it can be seen that the increase in efficiency also increases by the portion filled with a dashed line.

Referring to FIG. 9, assuming that the annual freezing amount (freezing tone) is used substantially before and after the improvement, that is, the energy consumption is reduced by the post-improvement operation method in the refrigerator system that provides the same result. There is a number.

As can be seen from the results shown again in FIG. 8, the efficiency according to the individual refrigerators 120, 130, and 140 can be continuously monitored. Therefore, when a specific refrigerator needs to be stopped by the required number of real-time operations, it is possible to stop the refrigerator having the least efficiency and to receive necessary maintenance and management.

Conventionally, since the efficiency is not distinguished by the refrigerators, it can be seen that maintenance and management were possible only when the freezer failed and stopped, but according to the present invention, the decrease in efficiency can be checked even before the freezer stops and stops. In addition, as it is determined that the refrigerator is excessively operated, the refrigerator can be repaired after selecting a freezer requiring repair and selectively stopping the operation.

As described above, while having been described with reference to the preferred embodiment of the present invention, those skilled in the art various modifications and changes within the scope of the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that it can be changed.

1 is a view showing a driving assistance device for presenting a method of operating a refrigerator system according to an embodiment of the present invention.

2 is a graph for explaining the relationship between the load rate and the efficiency of the refrigerator.

3 is a graph for explaining a load factor change of the refrigerator during operation of the refrigerator system.

4 is a graph for explaining a change in efficiency of the refrigerator during operation of the refrigerator system.

5 is a flowchart for providing an optimal driving method for energy saving according to an embodiment of the present invention.

6 is a graph showing a change in the relationship between the efficiency and the load factor according to an embodiment of the present invention.

7 is a graph showing a change in load ratio with time.

8 is a graph showing a change in efficiency over time.

9 is a graph comparing energy consumption.

Claims (17)

A method of operating a refrigerator system in which a plurality of refrigerators are connected in parallel, Collecting the instantaneous freezing amount of each of the freezers in a database; Comparing the real-time running number of the freezer with the real-time required running number from the instantaneous freezing amount collected in the database; And And presenting a comparison result according to the required number of real-time operations. The real-time required number of operations N _{s (d)} is the instantaneous freezing amount (C _s ) of the freezer system measured in real time, the rated freezing amount (C _{s (d)} ) of the freezer system measured in real time and the real-time operating number of the freezer Operating method of the refrigerator system, characterized in that calculated by comparing (N _s ). The method of claim 1, The refrigerator includes an automatic control circuit for independently controlling the operating conditions, the operation method of the refrigerator system, characterized in that for automatically controlling the operating capacity according to the flow rate or temperature of the output side of the cold water. delete The method of claim 1, The real-time required number of operations N _{s (d)} is calculated by the following equation.

(Here, Roundup () is a function that provides a natural number rounded the value in parentheses to the nearest decimal point.) The method of claim 1, When the real-time required number of operations (N _{s (d)} ) is less than the real-time number of operations (N _s ), the refrigerator system characterized in that the comparison results to stop the operation from the least efficient operation of the freezer to operate How to operate. The method of claim 1, When the real-time required number of operations (N _{s (d)} ) is less than the real-time number of operations (N _s ), the freezer characterized in that the comparison results to stop the operation from the smallest of the rated refrigeration of the operation is small How to operate the system. The method of claim 1, If the real-time required number of operations (N _{s (d)} ) is greater than the real-time number of operations (N _s ), the refrigerator system characterized in that the comparison results to start the operation from the most efficient of the refrigeration unit is stopped How to operate. The method of claim 1, When the real-time required number of operations (N _{s (d)} ) is greater than the real-time number of operations (N _s ), the freezer characterized in that the comparison results to start the operation starting from the smallest of the refrigeration amount of the refrigeration is stopped How to operate the system. The method of claim 1, In the step of presenting a comparison result according to the real-time required number of operations, Operating method of the refrigerator system, characterized in that for providing a refrigerator that needs to start or stop operation of the freezer. The method of claim 1, In the step of presenting a comparison result according to the real-time required number of operations, Operating method of the refrigerator system, characterized in that for providing a number of refrigerators that need to start or stop operation of the refrigerator. In the driving assistance equipment which presents a method of operating the refrigerator system by connecting a network of refrigerator systems in which a plurality of refrigerators are connected in parallel, A data storage unit for collecting the instantaneous freezing amount of each freezer from the network in a database; A calculation unit for comparing the real-time operation number of the refrigerator with the real-time required operation number from the instant freezing amount collected in the data storage unit; And And an information transfer unit for presenting a comparison result according to the required number of real-time operations. The information transmitting unit, the operation assistance equipment of the refrigerator system, characterized in that for providing a refrigerator that needs to start or stop operation of the refrigerator. In the driving assistance equipment which presents a method of operating the refrigerator system by connecting a network of refrigerator systems in which a plurality of refrigerators are connected in parallel, A data storage unit for collecting the instantaneous freezing amount of each freezer from the network in a database; A calculation unit for comparing the real-time operation number of the refrigerator with the real-time required operation number from the instant freezing amount collected in the data storage unit; And And an information transfer unit for presenting a comparison result according to the required number of real-time operations. The information transmission unit provides an operation aid of the refrigerator system, characterized in that for providing the number of the refrigerator to start or stop operation of the freezer. 13. The method according to claim 11 or 12, The refrigerator includes an automatic control circuit for independently controlling the operating conditions, the operation auxiliary equipment of the refrigerator system, characterized in that for automatically controlling the operating capacity according to the flow rate and temperature of the output side of the cold water. 13. The method according to claim 11 or 12, The refrigerator is equipped with a flow sensor for measuring the instantaneous freezing amount, a temperature sensor and a power sensor for detecting the motor drive of the freezer, respectively, the data storage unit data from the flow sensor, the temperature sensor and the power sensor Operating aids of the refrigerator system, characterized in that to collect. 13. The method according to claim 11 or 12, And the information transmitting unit transmits a comparison result according to the required number of real-time operations to the central control unit of the refrigerator system through the network. 13. The method according to claim 11 or 12, The information transmission unit operating aids of the refrigerator system, characterized in that for providing a comparison result according to the real-time required number of operations through its display unit. delete

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