Automatic control method and control system for centralized cooling system
阅读说明：本技术 用于集中供冷系统的自控方法及控制系统 (Automatic control method and control system for centralized cooling system ) 是由 滕林 古林平 朱清华 杨日贵 于 2021-09-09 设计创作，主要内容包括：本发明公开一种用于集中供冷系统的自控方法及控制系统。用于集中供冷系统的自控方法,包括以下步骤：构建周系数表,周系数记为M；构建变温系数,变温系数记为N；获取昨日售冷量,昨日售冷量记为H-(s)；计算预制冷量H-(b),利用预制冷量H-(b)对若干制冷机组进行自动控制。控制系统应用上述自控方法。本发明通过构建周系数表、变温系数,从而获得预测制冷量计算公式的模型架构,通过预测的制冷量对干制冷机组进行控制。将预测结果运用集中供冷系统中,能够制定合理的制冷方案,优化调整能量供应量,进一步提高了集中供冷系统运行的稳定性和能源的利用效率；实现节能、高效的设备制冷方案；能够提高设备效率,实现节能减排。(The invention discloses an automatic control method and a control system for a centralized cooling system. The automatic control method for the centralized cooling system comprises the following steps: constructing a week coefficient table, and recording the week coefficient as M; constructing a temperature change coefficient, and recording the temperature change coefficient as N; acquiring yesterday selling cold quantity, and recording the yesterday selling cold quantity as H s (ii) a Calculating prefabricated cold quantity H b Using prefabricated cold energy H b And automatically controlling the plurality of refrigerating units. The control system applies the automatic control method. The invention relates to aAnd constructing a cycle coefficient table and a temperature change coefficient to obtain a model framework of a predicted refrigerating capacity calculation formula, and controlling the dry refrigerating unit through the predicted refrigerating capacity. The prediction result is applied to the centralized cooling system, a reasonable refrigeration scheme can be formulated, the energy supply amount is optimized and adjusted, and the operation stability of the centralized cooling system and the utilization efficiency of energy are further improved; an energy-saving and efficient equipment refrigeration scheme is realized; the efficiency of the equipment can be improved, and energy conservation and emission reduction are realized.)
1. The automatic control method for the centralized cooling system, the centralized cooling system comprises a plurality of refrigerating units and a plurality of user cooling meters, is characterized by comprising the following steps,
constructing a week coefficient table, and recording the week coefficient as M;
constructing a temperature change coefficient, and recording the temperature change coefficient as N;
constructing a cold loss comparison table, and recording the cold loss as Hl；
Collecting cold quantity meter information of a plurality of users, acquiring yesterday cold quantity selling, and recording the yesterday cold quantity selling as Hs；
Acquiring the residual cold capacity of yesterday, and recording the residual cold capacity of yesterday as Hr；
Calculating the refrigerating capacity H of the current prefabricationb；
By using prefabricated cold energy HbThe automatic control is carried out on a plurality of refrigerating units,
wherein the calculation of the prefabricated cold quantity HbIn the steps of
Formula (1): hb＝Hs·M·N+Hl-Hr
Obtaining the prefabricated cold quantity H through the formula (1)b。
2. The autonomous method for concentrated cooling system according to claim 1 wherein the use of prefabricated cold HbIn the refrigeration control of a plurality of refrigeration units, including,
according to the prefabricated cold quantity HbThe opening number of the refrigerating unit is controlled according to the size of the refrigerant, so that the large load of the refrigerating unit is avoided;
will prefabricate cold energy HbOn average to the refrigeration unit turned on.
3. The autonomous method for concentrated cooling system according to claim 2, characterized in that the prefabricated cold quantity H is utilizedbIn the refrigeration control of a plurality of refrigeration units, the method also comprises the following steps,
and controlling the time-interval frequency refrigeration of the refrigeration unit.
4. The autonomous method for concentrated cooling system according to claim 3 wherein the prefabricated cold quantity H is utilizedbIn the refrigeration control of a plurality of refrigeration units, the method also comprises the following steps,
and a plurality of refrigerating units alternately work.
5. An autonomous method for a concentrated cooling system according to any of the claims 1-4 characterized by the step of obtaining yesterday's remaining cooling capacity in which:
obtaining yesterday refrigerating capacity which is recorded as Hb2；
Acquiring yesterday cold loss according to the cold loss comparison table, wherein yesterday cold loss is recorded as Hl2；
Formula (2): hr＝Hb2-Hs-Hl2
Obtaining yesterday residual cold quantity H through the formula (2)r。
6. The autonomous method for concentrated cooling system according to claim 5 wherein the step of obtaining yesterday's remaining capacity is:
the safety number is also set and marked as S;
formula (2): hr＝Hb2-Hs-Hl2-S
Obtaining yesterday residual cold quantity H through the formula (2)r(ii) a The step of obtaining the yesterday residual cold quantity comprises the following steps: when H is presentrWhen pi 0, default yesterday remains 0.
7. The autonomous method for concentrated cooling system according to any one of claims 1 to 4 wherein in the step of constructing a temperature change coefficient,
measuring temperature difference T, wherein T is the difference value between the environment temperature of yesterday and the environment temperature of today,
formula (3):
and (4) obtaining the temperature change coefficient N according to the formula (3).
8. The self-control method for a concentrated cooling system according to claim 7, wherein the concentrated cooling system further comprises a cooling tower, and the step of constructing the temperature change coefficient is a tower zone temperature difference of the cooling tower when the temperature difference T is 23: 30.
9. The autonomous method for concentrated cooling system according to any one of claims 1 to 4 wherein in the step of constructing the cycle index table,
the cycle coefficient M is respectively M0-0.7403, M1-1.8604, M2-0.9981, M3-1.0163, M4-1.0028, M5-1.0164 and M6-0.8299;
the first day-to-week coefficient M on the specific day is M6-0.8299, and the first day-to-week coefficient M on the specific day is M1-1.8604.
10. Control system, characterized in that it comprises an autonomous method for a central cooling system according to any of claims 1-9, further comprising,
a storage module configured to store data;
a measurement module configured to measure a temperature;
the computing module is configured to perform computing processing on the data;
and the control module is configured to automatically control the plurality of refrigerating units.
Technical Field
The invention relates to the technical field of cold quantity supply control, in particular to an automatic control system for a centralized cold supply system and a control system.
Background
With the development of cities, the increase of high-grade communities, office buildings and urban complexes, more and more centralized cooling systems such as central air conditioners are provided, the market is larger and larger, and the demand of multiple energy sources is increased. The cooling energy consumption accounts for 60% of the building energy consumption, so the energy-saving management of the centralized cooling system is particularly important. Currently, the general main control method of the centralized cooling system is as follows: the energy supply end cooling unit operates according to the fixed water outlet temperature, calculates the temperature difference value according to the return water temperature and the water temperature, loads or unloads the supply quantity according to the temperature difference value, and controls the supply quantity of the refrigerant medium. For example, in a refrigeration mode, the temperature difference is large, which indicates that the indoor temperature is high, the system load is large, and the supply amount should be increased by loading; otherwise, if the temperature difference is small, the indoor temperature is low, the system load is small, and the supply amount should be reduced.
The existing solutions for common energy supply end control systems (such as "central air conditioning automatic control system design" of hokkaido, and "central air conditioning energy saving and automatic control system design" of zhao literature), generally use programmable controller PLC or DDC as the core control system, the control mode includes that the equipment adopts closed-loop control, unit start/stop control, unit protection control, water supply pump control, unit operation mode control, circulating water pump control, cooling tower control, corresponding equipment interlock control, water supply and return pressure difference control, equipment interlock control, etc., and the control center of gravity is limited to the energy consumption supply end only. The energy output control mode of the energy supply end is as follows: the internal operation control of the cooling unit is automatically completed by the inside of the unit, and the external control system only controls the start and stop of the unit.
The control method has various defects, such as that environmental factors, human factors and the like are not considered, so that a larger difference value is generated between the predicted refrigerating capacity and the actual refrigerating capacity sold in the day, excessive refrigerating capacity is remained, and even the situation of short supply and short demand is generated.
Disclosure of Invention
According to one aspect of the present invention, there is provided
The automatic control method for centralized cooling system, which includes several refrigerating units and several user cooling meters, includes the following steps,
constructing a week coefficient table, and recording the week coefficient as M;
constructing a temperature change coefficient, and recording the temperature change coefficient as N;
constructing a cold loss comparison table, and recording the cold loss as Hl；
Collecting cold quantity meter information of a plurality of users, acquiring yesterday cold quantity selling, and recording the yesterday cold quantity selling as Hs；
Acquiring the residual cold capacity of yesterday, and recording the residual cold capacity of yesterday as Hr；
Calculating the refrigerating capacity H of the current prefabricationb；
By using prefabricated cold energy HbThe refrigeration control is carried out on a plurality of refrigeration units,
wherein the calculation of the prefabricated cold quantity HbIn the steps of
Formula (1): hb＝Hs·M·N+Hl-Hr
Obtaining the prefabricated cold quantity H through the formula (1)b。
The invention provides a method for predicting the refrigerating capacity of a centralized cooling system. In the invention, a model framework of a calculation formula is obtained by constructing a cycle coefficient table and a temperature change coefficient, and the prefabricated refrigeration capacity H is calculated by the formula (1)bCalculating; moreover, the method also considersTo the cold energy loss generated during the cold energy transmission, the residual cold energy H of yesterdayrAnd the result of the prediction of the refrigeration is more accurate by being incorporated into the algorithm, so that the refrigeration quantity to be manufactured by the equipment is obtained. The dry refrigerating unit is controlled through the predicted refrigerating capacity, so that the refrigerating time can be reasonably distributed, the refrigerating capacity is prevented from being larger than the output quantity, the energy can be saved, and the operating cost of an enterprise is reduced.
In some embodiments, the utilizing of the prefabricated cold quantity HbIn the refrigeration control of a plurality of refrigeration units, including,
according to the prefabricated cold quantity HbThe opening number of the refrigerating unit is controlled according to the size of the refrigerant, so that the large load of the refrigerating unit is avoided; will prefabricate cold energy HbOn average to an on refrigeration unit.
Thus, the above is one of the control items for controlling the refrigeration unit.
In some embodiments, the utilizing of the prefabricated cold quantity HbIn the refrigeration control of the plurality of refrigerating units, the method also comprises the step of controlling the time-interval frequency refrigeration of the refrigerating units.
Thus, the above is one of the control items for controlling the refrigeration unit.
In some embodiments, the utilizing of the prefabricated cold quantity HbIn the refrigeration control of the plurality of refrigeration units, the method also comprises the step of alternately working the plurality of refrigeration units.
Thus, the above is one of the control items for controlling the refrigeration unit.
In some embodiments, in the step of obtaining the yesterday remaining cold:
obtaining yesterday refrigerating capacity which is recorded as Hb2；
Acquiring yesterday cold loss according to the cold loss comparison table, wherein yesterday cold loss is recorded as Hl2；
Formula (2): hr＝Hb2-Hs-Hl2
Obtaining the yesterday residual cold quantity H by the formula (2)r。
Therefore, the residual cold is obtained through the formula (2), and the accuracy of the prefabricated cold is ensured.
In some embodiments, in the step of obtaining the yesterday remaining cold:
the safety number is also set and marked as S; the formula (2) is corrected,
formula (2): hr＝Hb2-Hs-Hl2-S
Obtaining the yesterday residual cold quantity H by the formula (2)rWhen H is presentrWhen pi 0, default yesterday remains 0.
Therefore, in order to avoid errors in calculation of the residual cold quantity in the formula, the formula (2) is provided with the insurance number S, and the condition that the prefabricated cold quantity obtained by the formula (1) is insufficient is avoided; also, when the remaining cold quantity H obtained by the formula (2)rAnd when the temperature is pi 0, the default residual cold quantity is 0, so that the condition that the prefabricated cold quantity obtained by the formula (1) is insufficient is avoided.
In some embodiments, in the step of constructing the temperature change coefficient,
measuring temperature difference T, wherein T is the difference value between the environment temperature of yesterday and the environment temperature of today,
formula (3):
and (4) constructing a temperature change coefficient N according to the formula (3).
Therefore, the temperature change coefficient N is constructed by the formula and needs to be substituted into the temperature difference T for operation.
In some embodiments, in the step of constructing the week coefficient table,
the cycle coefficient M is respectively M0-0.7403, M1-1.8604, M2-0.9981, M3-1.0163, M4-1.0028, M5-1.0164 and M6-0.8299 which are cyclically changed in one cycle.
Thus, the week coefficient is constructed with the working day of one week as the cycle, and M0 is 0.7403 for the week day, and so on.
In some embodiments, the prefabricated cold quantity H is obtained by formula (1)bWherein the first day cycle coefficient M of a specific day is M6-0.8299, and the first day cycle coefficient after the specific day isThe number M is M1-1.8604.
Thus, a particular date, i.e., a holiday. On the first day of the holiday, the coefficient M is M6-0.8299, and the other M is MtWhen the first day cycle coefficient M after a specific day is equal to 1, M1 is equal to 1.8604.
According to an aspect of the present invention, there is provided a control system applying the above automatic control method for a concentrated cooling system, including,
a storage module configured to store data;
a measurement module configured to measure a temperature;
the computing module is configured to perform computing processing on the data;
and the control module is configured to control the centralized cooling system.
In the control system applying the prediction method, the storage module can store data, the calculation module calculates and processes the data so as to obtain the predicted refrigerating capacity, and the control module reasonably distributes the refrigerating time and the refrigerating plan of the centralized cold supply system according to the predicted refrigerating capacity.
The invention has the following beneficial effects: according to the invention, the model framework of the calculation formula for predicting the refrigerating capacity is obtained by constructing the cycle coefficient table and the temperature change coefficient. The prediction result is applied to the centralized cooling system, a reasonable refrigeration scheme can be formulated, the energy supply amount is optimized and adjusted, and the operation stability of the centralized cooling system and the utilization efficiency of energy are further improved; an energy-saving and efficient equipment refrigeration scheme is realized; the efficiency of the equipment can be improved, and energy conservation and emission reduction are realized.
Drawings
Fig. 1 is a schematic structural diagram of a concentrated cooling system according to an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a control system according to an embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a control method according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Fig. 1 schematically shows a relationship structure between a concentrated cooling system and a user.
Referring to fig. 1-3, the centralized cooling system includes a plurality of refrigeration units, a plurality of user cooling meters, a cooling tower, and the like, which are not described in detail in this embodiment. The automatic control method for the centralized cooling system comprises the following steps,
constructing a week coefficient table, and recording the week coefficient as M;
constructing a temperature change coefficient, and recording the temperature change coefficient as N;
constructing a cold loss comparison table, and recording the cold loss as Hl；
Collecting information of cold quantity meters of a plurality of users, acquiring yesterday selling cold quantity, and recording the yesterday selling cold quantity as Hs；
Acquiring the residual cold capacity of yesterday, and recording the residual cold capacity of yesterday as Hr；
Calculating the refrigerating capacity H of the current prefabricationb；
By using prefabricated cold energy HbThe refrigeration control is carried out on a plurality of refrigeration units,
wherein the calculation of the prefabricated cold quantity HbIn the steps of
Formula (1): hb＝Hs·M·N+Hl-Hr
Obtaining the prefabricated cold quantity H through the formula (1)b。
The invention provides a method for predicting the refrigerating capacity of a centralized cooling system. In the invention, a model framework of a calculation formula is obtained by constructing a cycle coefficient table and a temperature change coefficient, and the prefabricated refrigeration capacity H is calculated by the formula (1)bCalculating; furthermore, the method also takes into account the loss of cooling capacity which can be generated during the transportation of cooling capacity, and also the residual cooling capacity H of yesterdayrAnd the result of the prediction of the refrigeration is more accurate by being incorporated into the algorithm, so that the refrigeration quantity to be manufactured by the equipment is obtained. The dry refrigerating unit is controlled through the predicted refrigerating capacity, so that the refrigerating time can be reasonably distributed, the refrigerating capacity is prevented from being larger than the output quantity, the energy can be saved, and the operating cost of an enterprise is reduced.
Further, the prefabricated cold energy H is utilizedbIn the refrigeration control of a plurality of refrigeration units, including,
according to the prefabricated cold quantity HbThe opening number of the refrigerating unit is controlled according to the size of the refrigerant, so that the large load of the refrigerating unit is avoided; will prefabricate cold energy HbOn average to an on refrigeration unit. For example, the daily average refrigerating capacity load of each refrigerating unit is 10 kilo-watts (KWH), and the prefabricated refrigerating capacity is HbIf the refrigerating capacity is 58 ten thousand KWH, six refrigerating units are required to be started, and the refrigerating capacity of each refrigerating unit is 58/6 ten thousand KWH;
and controlling the time-interval frequency refrigeration of the refrigerating unit. For example, the temperature at night is low, the cooling tower has good heat dissipation effect, and the refrigerating frequency of the refrigerating unit distributed at night is high;
and a plurality of refrigerating units alternately work. For example, the concentrated cooling system is provided with seven groups of refrigeration units, respectively identified as A, B, C, D, E, F, G; the starting unit for Monday is A, B, C, D, E, F, the starting unit for Tuesday is B, C, D, E, F, G, the starting unit for Wednesday is C, D, E, F, G, A, and so on. If, the prefabricated cold quantity H of a certain daybIf the number of the started refrigerating units is less than the specific value, the number of the started refrigerating units is less than six, and the refrigerating unit with the largest starting frequency in the setting of starting in the sequence is given priority to rest.
According to the prefabricated cold quantity HbThe method is one of the most important links in the field of making a system refrigeration scheme, and can improve the prefabricated cold quantity HbThe accuracy of (2).
According to the prefabricated cold quantity HbThe refrigeration solution of (a) may also include other controls, such as any other existing controls, such as transfer passages.
In the step of constructing the cold loss comparison table, the actual refrigerating output and the actual refrigerating output per day are led out from the historical database, and the cold loss is recorded as HlThe actual refrigerating capacity-the actual refrigerating capacity sold. Therefore, a cold loss amount comparison table as shown in table 1 was constructed. In application, the data of the reference table of the accessory 2 is integrated into a control system, and the control system can output the cold loss according to the predicted cold sale amount and temperature conditions.
Table 1: the data are shown above when T is greater than 28 ℃ and the data below when T is less than or equal to 28 ℃. (column zone temperature difference when T is 23: 30)
When the cold storage warehouse still has no cold sold in yesterday, the method for predicting the refrigerating capacity of the concentrated cold supply system further comprises the following steps: and acquiring the residual cooling capacity of yesterday. The method also compares the residual cooling capacity H of yesterdayrAnd the method is incorporated into a prediction method, so that the refrigeration prediction result is more accurate, and excessive surplus is avoided.
Further, in the step of obtaining the residual cooling capacity of yesterday:
obtaining yesterday refrigerating capacity which is recorded as Hb2；
Acquiring yesterday cold loss according to the cold loss comparison table, wherein yesterday cold loss is recorded as Hl2；
Formula (2): hr＝Hb2-Hs-Hl2
Obtaining the yesterday residual cold quantity H by the formula (2)r. The residual cold quantity is obtained through the formula (2), and the accuracy of the prefabricated cold quantity is ensured.
Further, in the step of obtaining the residual cooling capacity of yesterday: the safety number is also set and marked as S; the formula (2) is corrected,
formula (2): hr＝Hb2-Hs-Hl2-S
Obtaining the yesterday residual cold quantity H by the formula (2)r. The method comprises the following steps of obtaining yesterday residual cold quantity: when H is presentrWhen pi 0, default yesterday remains 0. When the residual cold quantity H obtained by the formula (2)rAnd when the temperature is pi 0, the default residual cold quantity is 0, so that the condition that the prefabricated cold quantity obtained by the formula (1) is insufficient is avoided.
Further, in the step of constructing the temperature variation coefficient, the temperature difference T is measured, wherein T is the difference value between the environment temperature of yesterday and the environment temperature of this day, T is the temperature difference of the tower area when T is 23:30,
formula (3):
and (4) constructing a temperature change coefficient N according to the formula (3). The temperature change coefficient N is constructed by the above formula, and needs to be substituted into the temperature difference T for operation, as shown in table 2.
Table 2: the temperature-changing coefficient (N) can be obtained by directly substituting T into the formula (3).
Further, in the step of constructing the cycle coefficient table, the cycle coefficients are cyclically changed according to a cycle of one week, and the cycle coefficients M are respectively M0-0.7403, M1-1.8604, M2-0.9981, M3-1.0163, M4-1.0028, M5-1.0164, and M6-0.8299. The week coefficient is constructed by taking the working day of one week as a period, and M0 is 0.7403 on the day of the week, and so on.
Further, the prefabricated cold quantity H is obtained through the formula (1)bIn the above description, the first day-to-week coefficient M on a specific day is M6-0.8299, and the first day-to-week coefficient M on a specific day is M1-1.8604. A particular date, i.e., a holiday. On the first day of the holiday, the coefficient M is M6-0.8299, and the other M is MtWhen the first day cycle coefficient M after a specific day is equal to 1, M1 is equal to 1.8604.
For example, the week coefficient is calculated as follows according to the normal working day:
day of the week: hb＝Hs·M·N+Hl-Hr(M is M0, M0 ═ 0.7403)
And B, Monday: hb＝Hs·M·N+Hl-Hr(M is M1, M1 ═ 1.8604)
And B, Tuesday: hb＝Hs·M·N+Hl-Hr(M is M2, M2 ═ 0.9981)
And D, three weeks: hb＝Hs·M·N+Hl-Hr(M is M3, M3 ═ 1.0163)
B, B: hb＝Hs·M·N+Hl-Hr(M is M4, M4 ═ 1.0028)
Friday: hb＝Hs·M·N+Hl-Hr(M is M5, M5 ═ 1.0164)
Saturday: hb＝Hs·M·N+Hl-Hr(M is M6, M6 is 0.8299).
If the national public holiday is met, if the holiday is three days, the public holiday (holiday day) and the first day after the public holiday are calculated as follows:
the first day of public holiday: hb＝Hs·M·N+Hl-Hr(M is M6, M6 ═ 0.8299)
B, second holiday: hb＝Hs·M·N+Hl-Hr(M is Mt, Mt＝1)
B, three days of public rest: hb＝Hs·M·N+Hl-Hr(M is Mt, Mt＝1)
After the section: hb＝Hs·M·N+Hl-Hr(M is M1, M1 is 1.8604).
Referring to fig. 3, a control system for applying the above-described automatic control method for a concentrated cooling system includes:
a storage module configured to store data;
a measurement module configured to measure a temperature;
the computing module is configured to perform computing processing on the data;
and the control module is configured to automatically control the centralized cooling system.
In the control system applying the prediction method, the storage module can store data, the calculation module calculates and processes the data so as to obtain the predicted refrigerating capacity, and the control module reasonably distributes the refrigerating time and the refrigerating plan of the centralized cold supply system according to the predicted refrigerating capacity.
The refrigerating plans of the refrigerating units can be reasonably distributed according to the prediction method, and reasonable refrigerating plans such as the number of the units, the refrigerating time, the refrigerating frequency and the like can be formulated.
According to the invention, the model framework of the calculation formula for predicting the refrigerating capacity is obtained by constructing the cycle coefficient table and the temperature change coefficient. The prediction result is applied to the centralized cooling system, a reasonable refrigeration scheme can be formulated, the energy supply amount is optimized and adjusted, and the operation stability of the centralized cooling system and the utilization efficiency of energy are further improved; an energy-saving and efficient equipment refrigeration scheme is realized; the efficiency of the equipment can be improved, and energy conservation and emission reduction are realized.
What has been described above are merely some embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept thereof, and these changes and modifications can be made without departing from the spirit and scope of the invention.