Optimal Control Method for Process Air Conditioning

Abstract

The present invention discloses an optimal control method for a process air conditioner, comprising: determining the operating condition of the process air conditioner; if the operating condition is high humidity, dividing the temperature of the controlled area into N levels on a psychrometric diagram, and selecting N points on the boundary line as control target temperature and humidity points; during the process of switching from the high humidity operating condition to the controlled area, determining whether overcooling exists based on whether the current ambient temperature and humidity point coincides with one of the control target temperature and humidity points on the boundary line; if they coincide, indicating overcooling exists, the energy consumption corresponding to the current ambient temperature and humidity point is compared with the energy consumption corresponding to the lowest control target temperature and humidity point higher than the current ambient temperature and humidity point, and determining whether to execute temperature increase control based on the energy consumption comparison result. The optimal control method for the process air conditioner provided by the present invention can achieve the purpose of improving the dynamic adjustment performance of the process air conditioner in the cigarette factory and reducing the energy consumption of the equipment by calculating and fitting the optimal target temperature and humidity in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning control, and in particular to an optimal control method for process air conditioning. Background Art

[0002] With the continuous development of modern industrial production technology and the continuous improvement of product processing precision, constant temperature and humidity air conditioning systems have been widely used in various industries both domestically and internationally. The vigorous development of my country's domestic air conditioning industry and the emergence of various sensor technologies have laid a solid foundation for achieving different levels of temperature and humidity control precision, and have also promoted the application of constant temperature and humidity air conditioning in more fields. The raw materials and production process in the production area of ​​cigarette factories have extremely strict regulations on the temperature and humidity of the environment. Short-term fluctuations can affect the moisture content and crushing rate of cut tobacco, which in turn has a negative impact on product quality.

[0003] Temperature and humidity control in tobacco production and storage is primarily achieved through centralized control of large-scale process air conditioning systems, typically supplied by a full air system. This system provides precise thermal and humidity conditions for the controlled areas. Therefore, its temperature and humidity control system must provide cooling, heating, humidification, and dehumidification functions. It typically consists of a heat and cooling source, an air handling unit (AHU), supply and return air ducts, and a control system. Current temperature and humidity control strategies for tobacco factory process air conditioning systems suffer from energy waste due to inadequate setpoint adjustments during winter and summer, especially in summer mode. When the target temperature is set too low, high dehumidification demand can lead to overcooling due to insufficient dehumidification capacity. This can cause the ambient temperature to remain very low, resulting in excessive relative humidity, exceeding the control range, and wasting energy and preventing the target from being achieved. If the target temperature is set too high, the heating valve will frequently activate to reduce the temperature due to dehumidification demand, further wasting energy and preventing manual control from achieving the optimal target setting.

[0004] Therefore, there is an urgent need for an optimal control method for process air conditioning. Summary of the Invention

[0005] The purpose of the present invention is to provide an optimal control method for process air conditioning to solve the problems in the above-mentioned prior art. By real-time calculation and fitting of the optimal target temperature and humidity, the dynamic adjustment performance of the process air conditioning in the cigarette factory can be improved and the energy consumption of the equipment can be reduced.

[0006] The present invention provides an optimal control method for process air conditioning, comprising the following steps:

[0007] Determine the working conditions of the process air conditioning;

[0008] If it is a high humidity working condition, the temperature of the controlled area A is divided into N levels on the enthalpy-humidity diagram, and N points are taken on the boundary line of the controlled area A close to the high humidity working condition area as the control target temperature and humidity points;

[0009] When the process air conditioner is switched from a high humidity condition to the controlled area A, whether there is over-cooling is determined based on whether the current ambient temperature and humidity point x coincides with one of the control target temperature and humidity points on the boundary line;

[0010] If they coincide, it is determined that there is over-cooling. At this time, the energy consumption corresponding to the current ambient temperature and humidity point x is compared with the energy consumption corresponding to the lowest control target temperature and humidity point higher than the current ambient temperature and humidity point x, and whether to perform temperature increase control at the current ambient temperature and humidity point x is determined based on the energy consumption comparison result.

[0011] As described above, in the optimal control method for process air conditioning, preferably, the controlled area A is an interval on the enthalpy-humidity diagram where the temperature is between the lower temperature limit T1 and the upper temperature limit T2, and the moisture content is between the lower relative humidity limit H1 and the upper relative humidity limit H2.

[0012] In the above-mentioned optimal control method for process air conditioning, preferably, under high humidity conditions, the temperature of the controlled area A is divided into N levels on the psychrometric diagram, and N points are selected as control target temperature and humidity points on the boundary line of the controlled area A close to the high humidity condition zone, specifically including:

[0013] On the psychrometric chart, the temperature range between the lower temperature limit T1 and the upper temperature limit T2 of the controlled area A is divided into N sections from bottom to top, and the boundary line between the controlled area A and the high humidity working area is divided into N control target temperature and humidity points, namely P1, P2, P3, ..., P N , where the target temperature and humidity point P is controlled i The corresponding temperature is T i , the corresponding humidity is H i , where 1≤i≤N.

[0014] In the above-mentioned optimal control method for process air conditioning, preferably, when it is determined that there is overcooling, the energy consumption corresponding to the current ambient temperature and humidity point x is compared with the energy consumption corresponding to the lowest control target temperature and humidity point higher than the current ambient temperature and humidity point x, and whether to perform temperature increase control at the current ambient temperature and humidity point x is determined based on the energy consumption comparison result, specifically including:

[0015] Step S41: Set the temperature of the initial ambient temperature and humidity point x to T0, the moisture content to H0, and the corresponding control target temperature and humidity point to P x ;

[0016] Step S42: Calculate the current control target temperature and humidity point P using the following formula: x The total energy consumption of the heating valve in the following duration t is:

[0017]

[0018] Among them, Q w represents the total energy consumption of the heating valve in time t, C represents the heat capacity ratio of water, ΔT w Indicates the inlet and outlet water temperature difference of the heating valve, ρ w Indicates the density of water passing through the heating valve, V ω Indicates the water flow rate through the heating valve, A ω represents the cross-sectional area of ​​the heating valve, and t represents the heating duration;

[0019] Step S43: Calculate the current control target temperature and humidity point P using the following formula: x The total energy consumption of the surface cooling valve in the duration t is:

[0020]

[0021] Among them, Q c represents the total energy consumption of the surface cooling valve in time t, C represents the heat capacity ratio of water, ΔT c Indicates the inlet and outlet water temperature difference of the surface cooling valve, ρ c Indicates the density of water passing through the surface cooling valve, V c Indicates the water flow rate through the surface cooling valve, A c represents the cross-sectional area of ​​the surface cooling valve, and t represents the duration;

[0022] Step S44: Calculate the total energy consumption within the duration t using the following formula:

[0023] Q x =Q w +Q c (3)

[0024] Among them, Q x It represents the total energy consumption of the heating valve and the surface cooling valve in time t;

[0025] Step S45: Calculate the total energy consumption Q at the initial ambient temperature and humidity point x within the duration t using formula (1)-formula (3): x ;

[0026] Step S46: Calculate the upper level control target temperature and humidity point P of the initial environment temperature and humidity point x by formula (1)-formula (3) x+1 The total energy consumption Q during the duration t x+1 ;

[0027] Step S47: Compare Qx and Q x+1 If the size of Q x+1 <Q x , then the upper level control target temperature and humidity point P x+1 The control target temperature and humidity point corresponding to the initial ambient temperature and humidity point x is P x More energy-efficient;

[0028] Step S48: Let x = x + 1, and repeat steps S45 to S47 to calculate the current control target temperature and humidity point P. x The upper control target temperature and humidity point P x+1 The corresponding energy consumption Q x+1 , and compare the current control target temperature and humidity point P x Energy consumption Q x And the corresponding upper control target temperature and humidity point P x+1 Energy consumption Q x+1 , until the upper level controls the energy consumption Q of the target temperature and humidity point x+1 Greater than the energy consumption Q of the current control target temperature and humidity point x , then determine the current control target temperature and humidity point P x It is the optimal control target temperature and humidity point.

[0029] As described above, the optimal control method for process air conditioning, wherein preferably, the optimal control method for process air conditioning further comprises:

[0030] The economic cost is determined based on the energy consumption corresponding to the current ambient temperature and humidity point x, and the optimal control target temperature and humidity point is determined based on the economic cost, specifically including:

[0031] Calculate the current control target temperature and humidity point P by the following formula x The economic cost of the cooling valve is shown in the table below:

[0032] M c =Q c / COP 冷 *U (4)

[0033] Among them, M c Represents the total energy consumption Q of the surface cooling valve in time t c The economic cost, Q c Indicates the total energy consumption of the surface cooling valve in time t, COP 冷 represents the cooling coefficient of the refrigerator, and U represents the unit price of electricity;

[0034] Calculate the current control target temperature and humidity point P by the following formula x Economic cost of lower heating valve in steam mode M w :

[0035] M w=(Q w / W / R)*Y (5)

[0036] Among them, Q w represents the total energy consumption of the heating valve in time t, W and R represent the steam calorific value and steam-gas ratio in steam heating mode, and Y represents the unit price of natural gas;

[0037] Calculate the current control target temperature and humidity point P by the following formula x Economic cost of lower heating valve in heat pump mode M w :

[0038] M w =Q w / COP 泵 *U (6)

[0039] Among them, COP 泵 It represents the heating coefficient of the heat pump in heating mode, and U represents the unit price of electricity;

[0040] Calculate the current control target temperature and humidity point P by the following formula x The total economic cost M of the cooling valve and heating valve in the table below x :

[0041] M x =M c +M w (7)

[0042] Among them, M c Calculated by formula (4), M w Calculated by formula (5) or (6);

[0043] According to formula (7), calculate the current control target temperature and humidity point P x The corresponding total economic cost M x , and the current control target temperature and humidity point P x The upper control target temperature and humidity point P x+1 The corresponding total economic cost M x+1 ;

[0044] If M x <M x+1 , then the current control target temperature and humidity point P x To optimally control the target temperature and humidity points;

[0045] If M x >M x+1 , we can determine the temperature and humidity point P that is the current control target x Compared with the upper control target temperature and humidity point P x+1 More energy-saving, at this time, change the current control target temperature and humidity point to P x+1 , continue to Px+1 The corresponding total economic cost M x+1 and P x+2 The corresponding total economic cost M x+2 Compare until the smallest M is found x value, the smallest M x The current control target temperature and humidity point P corresponding to the value x It is the optimal control target temperature and humidity point.

[0046] As described above, the optimal control method for process air conditioning, wherein preferably, the optimal control method for process air conditioning further comprises:

[0047] The discounted benefit is determined based on the energy consumption corresponding to the current ambient temperature and humidity point x, and the optimal control target temperature and humidity point is determined based on the discounted benefit, specifically including:

[0048] Calculate the current control target temperature and humidity point P by the following formula x Total standard coal K in steam mode x :

[0049] K x =(Q c / COP 冷 )*K 电 +(Q w / W)*K 汽 (8)

[0050] Among them, Q c Indicates the total energy consumption of the surface cooling valve in time t, COP 冷 Indicates the refrigeration coefficient of the refrigerator, Q w represents the total energy consumption of the heating valve in time t, W represents the calorific value of steam in steam heating mode, K 电 Indicates the preset electrical rebate coefficient, K 汽 Indicates the preset steam reduction coefficient;

[0051] Calculate the current control target temperature and humidity point P by the following formula x Total standard coal K in heat pump mode x :

[0052] K x =(Q c / COP 冷 )*K 电 +(Q w / COP 泵 )*K 电 (9)

[0053] Among them, COP 泵 Indicates the heating coefficient of the heat pump in heating mode;

[0054] According to formula (9), calculate the current control target temperature and humidity point P x Corresponding total standard coal K x , and the current control target temperature and humidity point P x The upper control target temperature and humidity point P x+1 Corresponding total standard coal K x+1 ;

[0055] If K x <K x+1 , then the current control target temperature and humidity point P x To optimally control the target temperature and humidity points;

[0056] If K x >K x+1 , we can determine the temperature and humidity point P that is the current control target x Compared with the upper control target temperature and humidity point P x+1 More energy-saving, at this time, change the current control target temperature and humidity point to P x+1 , continue to P x+1 Corresponding total standard coal K x+1 and P x+2 The corresponding total economic cost K x+2 Compare until the smallest K is obtained x value, the smallest K x The current control target temperature and humidity point P corresponding to the value x It is the optimal control target temperature and humidity point.

[0057] As described above, the optimal control method for process air conditioning, wherein preferably, the optimal control method for process air conditioning further comprises:

[0058] If the current ambient temperature and humidity point x does not coincide with one of the control target temperature and humidity points on the boundary line, it is determined that there is no over-cooling, and after the current ambient temperature and humidity point x enters the controlled area A, the target temperature and humidity value P of the current ambient temperature and humidity point x is set to the lowest target temperature and humidity point P1 of the controlled area A.

[0059] The optimal control method of the process air conditioner of the present invention compares the energy consumption corresponding to the current ambient temperature and humidity point x with the energy consumption corresponding to the temperature and humidity point higher than the previous level control target when over-cooling exists, and determines whether to perform temperature increase control at the current ambient temperature and humidity point x based on the energy consumption comparison result. The most energy-saving target temperature and humidity are obtained through real-time calculation, and the actual working condition output is determined according to the current dehumidification capacity, thereby preventing or reducing over-cooling caused by dehumidification and reducing energy waste; only the controlled temperature and humidity range needs to be obtained, and the winter and summer mode switching can be canceled; the target value is set during the temperature and humidity control process, and the actual control working condition is determined based on the target value. By finding and setting the optimal target value, it is helpful to quickly achieve the control target value, thereby improving the control capability and control efficiency of the process air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0061] Figure 1 Psychrometric diagram for process air conditioning;

[0062] Figure 2 Schematic diagram of the control strategy for high humidity conditions;

[0063] Figure 3 A flow chart of an embodiment of an optimal control method for process air conditioning provided by the present invention;

[0064] Figure 4 This is a schematic diagram of the working principle of an embodiment of the optimal control method for process air conditioning provided by the present invention. DETAILED DESCRIPTION

[0065] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure, its application, or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions, and numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0066] The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are simply used to distinguish different parts. Terms such as "include" or "comprising" mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements. Terms such as "upper," "lower," and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0067] In the present disclosure, when a specific component is described as being located between a first component and a second component, there may or may not be an intervening component between the specific component and the first component or the second component. When a specific component is described as being connected to another component, the specific component may be directly connected to the other component without an intervening component, or may not be directly connected to the other component but have an intervening component.

[0068] All terms (including technical or scientific terms) used in this disclosure have the same meaning as those understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined herein.

[0069] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0070] Tobacco production and storage systems primarily rely on centralized, large-scale process air conditioning systems, typically supplied by a full air system to provide a precise thermal and humidity environment for the controlled area. Therefore, the temperature and humidity control system must provide cooling, heating, humidification, and dehumidification functions. It typically consists of a heat and cooling source, an air handling cabinet, supply and return air ducts, and a control system.

[0071] For example, a process air conditioner cabinet houses the air supply and return motors and inverters, a surface cooler, a heater, a humidifier, and air conditioning filters. The controlled area's temperature and humidity conditions include: low temperature, high temperature, low humidity, high humidity, low temperature and low humidity, high temperature and low humidity, low temperature and high humidity, and high temperature and high humidity. To achieve the target temperature and humidity control requirements for each of these conditions, the current control output logic for process air conditioners in cigarette factories is converted as follows:

[0072] (1) Low temperature working condition: corresponding to the heating working condition, the control system outputs the heating output, the heater is working at this time, and the heater output = the system heating output;

[0073] (2) High temperature working condition: corresponding to the cooling working condition, the control system outputs the cooling output, at this time the surface cooler works, and the surface cooler output = the system cooling output;

[0074] (3) Low humidity working condition: corresponding to the humidification working condition, the control system outputs the humidification output, at this time the humidifier works, and the humidifier output = the system humidification output;

[0075] (4) High humidity working condition: corresponding to the dehumidification working condition, the control system outputs the dehumidification output, at this time the surface cooler works, and the surface cooler output = the system dehumidification output;

[0076] (5) Low temperature and low humidity working condition: corresponding to the heating and humidification working condition, the control system outputs the heating and humidification output. At this time, the heater and humidifier are working, the heater output = the system heating output, and the humidifier output = the system humidification output;

[0077] (6) High temperature and low humidity working condition: corresponding to the cooling and humidification working condition, the control system outputs the cooling and humidification output. At this time, the surface cooler and humidifier are working, the surface cooler output = the system cooling output, and the humidifier output = the system humidification output;

[0078] (7) Low temperature and high humidity working condition: corresponding to the heating and dehumidification working condition, the control system outputs the heating and dehumidification output. At this time, the heater and the surface cooler are working, the heater output = the system heating output, and the surface cooler output = the system dehumidification output;

[0079] (8) High temperature and high humidity working condition: corresponding to the cooling and dehumidification working condition, the control system outputs the cooling and dehumidification output. At this time, the surface cooler works, and the surface cooler output = the system cooling and dehumidification output.

[0080] From the above control logic, it can be concluded that in the process of adjusting temperature and humidity under different working conditions, the surface cooler will play the role of cooling and dehumidification. Figure 1 ) It can be obtained that under the condition of equal moisture content, an increase in temperature will cause a decrease in relative humidity, that is, the heater will cause the relative humidity to decrease.

[0081] See also Figure 1 , 8 current working conditions were analyzed and the following results were obtained:

[0082] Zone ① is in heating condition. When the heating valve is open, the temperature rises and the relative humidity decreases. The air will enter the controlled area A or zone ⑤ and be analyzed according to the corresponding zone conditions.

[0083] Zone ② is a high-temperature operating condition. The surface cooling valve is open, the temperature drops, and the relative humidity drops. It will enter the controlled area A or zone ⑧, and analysis will be performed according to the corresponding zone operating conditions.

[0084] Area ③ is a low humidity working condition. The humidification valve is opened, the relative humidity increases, and the air enters the controlled area A.

[0085] Zone ④ is a high-humidity working condition. The surface cooling valve is open, the temperature drops, and the relative humidity increases. It will enter the controlled area A or zone ⑦, and analysis will be performed according to the working conditions of the corresponding zone.

[0086] Area ⑤ is a low-temperature and low-humidity working condition. The heating valve and humidification valve are opened, the temperature rises, the relative humidity increases, and the controlled area A will be entered.

[0087] Area ⑥ is a high temperature and low humidity working condition. The surface cooling valve and humidification valve are open, the temperature drops, and the relative humidity increases, and the controlled area A will be entered.

[0088] Area ⑦ is a low-temperature and high-humidity working condition. The heating valve and the surface cooling valve are open, the temperature rises, and the relative humidity decreases, and it will enter the controlled area A.

[0089] Area ⑧ is a high temperature and high humidity working condition. The surface cooling valve is opened, the temperature drops, the relative humidity drops, and the controlled area A will be entered.

[0090] Analysis of the above results shows that, except for zone ④, there is no problem of cold and hot offset in other zones. After the operating conditions in zone ④ enter zone ⑦, the surface cooling valve and the heating valve are opened at the same time. It can be considered that the operating condition at this time is that the dehumidification demand is greater than the cooling demand, resulting in over-cooling and the need for the heating valve to compensate for the temperature. Because the surface cooling valve reduces the moisture content, the assessment standard of the cigarette factory is relative humidity. A decrease in temperature will lead to an increase in relative humidity, causing the surface cooling valve to continue to open wide, resulting in over-cooling, reducing dehumidification efficiency and wasting energy.

[0091] like Figure 2 As shown, area A is the temperature and humidity control range. Assuming that the current ambient temperature and humidity are at point X in area ④, that is, high humidity working conditions, at this time, in order to make the temperature and humidity reach the controlled range, the heating valve can be used to increase the temperature, or the surface cooling valve can be used to reduce the temperature and dehumidify the process control strategy, so that the target values ​​of temperature and humidity are controlled to P1, P2, P3, ..., P in area A. N Wait for any target point.

[0092] Different target values ​​dictate different control methods. Under the current control strategy, high-humidity conditions in Zone 4 only activate the surface cooling valve for dehumidification control. However, the dehumidification process reduces the absolute moisture content while also lowering the ambient temperature, leading to overcooling and impacting dehumidification efficiency. Because the assessment criterion is relative humidity, high unit loads prevent the relative humidity from being kept within a stable range, resulting in wasted energy. In this case, increasing the ambient temperature to raise the relative humidity can actually bring the ambient temperature and humidity into the controlled range quickly, saving energy.

[0093] The optimal control method for process air conditioning provided by the present invention is applicable to process air conditioning in cigarette factories, and is aimed at controlling the temperature and humidity of various heat and humidity actuators in process air conditioning in cigarette factories. It can also be used in the control process of process air conditioning in other industries, and the present invention does not make specific limitations on this.

[0094] like Figure 3 As shown, the optimal control method for process air conditioning provided by this embodiment includes the following steps during actual implementation:

[0095] Step S1: Determine the working condition of the process air conditioner.

[0096] Step S2: If the working condition is high humidity, the temperature of the controlled area A is divided into N levels on the enthalpy-humidity diagram, and N points are taken on the boundary line of the controlled area A close to the high humidity working condition area as the control target temperature and humidity points.

[0097] like Figure 4 As shown, the controlled area A is divided into N levels, and N points are taken on the boundary line close to the high humidity working area (area ④) as the control target temperature and humidity points.

[0098] Among them, such as Figure 2 As shown, the controlled area A is an interval where the temperature on the psychrometric diagram is between the lower temperature limit T1 and the upper temperature limit T2, and the moisture content is between the lower relative humidity limit H1 and the upper relative humidity limit H2.

[0099] Specifically, since the most energy-saving temperature and humidity target point must be at the boundary between the controlled area A and the high humidity working area (region ④), Figure 4 As shown in the psychrometric diagram, the temperature range between the lower temperature limit T1 and the upper temperature limit T2 of the controlled area A is divided into N segments from bottom to top, and the boundary line between the controlled area A and the high humidity working area is divided into N control target temperature and humidity points, namely P1, P2, P3, ..., P N , where the target temperature and humidity point P is controlled i The corresponding temperature is T i , the corresponding humidity is H i , where 1≤i≤N. It should be noted that, in a specific implementation, N target temperature and humidity control points can be divided according to the process requirements of the production area. In some embodiments of the present invention, the N target temperature and humidity control points can also be unequally divided. The present invention does not specifically limit the specific division strategy.

[0100] Step S3: When the process air conditioner is controlled to switch from the high humidity condition to the controlled area A, whether there is over-cooling is determined based on whether the current ambient temperature and humidity point x coincides with one of the control target temperature and humidity points on the boundary line.

[0101] Step S4: If they coincide, it is determined that there is over-cooling. At this time, the energy consumption corresponding to the current ambient temperature and humidity point x is compared with the energy consumption corresponding to the lowest control target temperature and humidity point higher than the current ambient temperature and humidity point x, and whether to perform temperature increase control at the current ambient temperature and humidity point x is determined based on the energy consumption comparison result.

[0102] like Figure 4 As shown, take the current ambient temperature and humidity point x, when x is in the high humidity working area (region ④), and when x touches the current control target temperature and humidity point P during the control process x The lower limit of temperature is the value of over-cooling, which means that the current control target temperature and humidity point P x The upper control target temperature and humidity point P within the desired temperature and humidity control range x+1 , by comparing P x+1 and P x The corresponding energy consumption situation is used to determine whether heating has the effect of reducing energy consumption.

[0103] like Figure 4 As shown, in one embodiment of the optimal control method of the process air conditioner of the present invention, the step S4 may specifically include:

[0104] Step S41: Set the temperature of the initial ambient temperature and humidity point x to T0, the moisture content to H0, and the corresponding control target temperature and humidity point to P x .

[0105] Step S42: Calculate the current control target temperature and humidity point P using the following formula: x The total energy consumption of the heating valve in the following duration t is:

[0106]

[0107] Among them, Q w represents the total energy consumption of the heating valve in time t, C represents the heat capacity ratio of water, ΔT w Indicates the inlet and outlet water temperature difference of the heating valve, ρ w Indicates the density of water passing through the heating valve, V ω Indicates the water flow rate through the heating valve, A ω represents the cross-sectional area of ​​the heating valve, and t represents the heating duration.

[0108] Step S43: Calculate the current control target temperature and humidity point P using the following formula: x The total energy consumption of the surface cooling valve in the duration t is:

[0109]

[0110] Among them, Q c represents the total energy consumption of the surface cooling valve in time t, C represents the heat capacity ratio of water, ΔT c Indicates the inlet and outlet water temperature difference of the surface cooling valve, ρ c Indicates the density of water passing through the surface cooling valve, V c Indicates the water flow rate through the surface cooling valve, A cIt represents the cross-sectional area of ​​the surface cooling valve, and t represents the duration.

[0111] Step S44: Calculate the total energy consumption within the duration t using the following formula:

[0112] Q x =Q w +Q c (3)

[0113] Among them, Q x Represents the total energy consumption of the heating valve and the surface cooling valve in time t.

[0114] Step S45: Calculate the total energy consumption Q at the initial ambient temperature and humidity point x within the duration t using formula (1)-formula (3): x .

[0115] Step S46: Calculate the upper level control target temperature and humidity point P of the initial environment temperature and humidity point x by formula (1)-formula (3) x+1 The total energy consumption Q during the duration t x+1 .

[0116] Step S47: Compare Q x and Q x+1 If the size of Q x+1 <Q x , then the upper level control target temperature and humidity point P x+1 The control target temperature and humidity point corresponding to the initial ambient temperature and humidity point x is P x More energy-efficient.

[0117] Step S48: Let x = x + 1, and repeat steps S45 to S47 to calculate the current control target temperature and humidity point P. x The upper control target temperature and humidity point P x+1 The corresponding energy consumption Q x+1 , and compare the current control target temperature and humidity point P x Energy consumption Q x And the corresponding upper control target temperature and humidity point P x+1 Energy consumption Q x+1 , until the upper level controls the energy consumption Q of the target temperature and humidity point x+1 Greater than the energy consumption Q of the current control target temperature and humidity point x , then determine the current control target temperature and humidity point P x It is the optimal control target temperature and humidity point.

[0118] In some embodiments of the present invention, the optimal control method for process air conditioning further includes:

[0119] Step S5: Determine the economic cost based on the energy consumption corresponding to the current ambient temperature and humidity point x, and determine the optimal control target temperature and humidity point based on the economic cost.

[0120] In one embodiment of the optimal control method for process air conditioning of the present invention, step S5 may specifically include:

[0121] Step S51: Calculate the current control target temperature and humidity point P by the following formula: x The economic cost of the cooling valve is shown in the table below:

[0122] M c =Q c / COP 冷 *U (4)

[0123] Among them, M c Represents the total energy consumption Q of the surface cooling valve in time t c The economic cost, Q c Indicates the total energy consumption of the surface cooling valve in time t, COP 冷 It represents the cooling coefficient of the refrigerator, and U represents the unit price of electricity.

[0124] Step S52: Calculate the current control target temperature and humidity point P using the following formula: x Economic cost of lower heating valve in steam mode M w :

[0125] M w =(Q w / W / R)*Y (5)

[0126] Among them, Q w represents the total energy consumption of the heating valve in time t, W and R represent the steam calorific value and steam-gas ratio in steam heating mode, and Y represents the unit price of natural gas.

[0127] Step S53: Calculate the current control target temperature and humidity point P by the following formula: x Economic cost of lower heating valve in heat pump mode M w :

[0128] M w =Q w / COP 泵 *U (6)

[0129] Among them, COP 泵 It represents the heating coefficient of the heat pump in heating mode, and U represents the unit price of electricity.

[0130] Step S54: Calculate the current control target temperature and humidity point P using the following formula: x The total economic cost M of the cooling valve and heating valve in the table below x :

[0131] M x =M c +M w (7)

[0132] Among them, M c Calculated by formula (4), M w Calculated using formula (5) or (6).

[0133] Step S55: Calculate the current control target temperature and humidity point P according to formula (7) x The corresponding total economic cost M x , and the current control target temperature and humidity point P x The upper control target temperature and humidity point P x+1 The corresponding total economic cost M x+1 .

[0134] Step S56: If M x <M x+1 , then the current control target temperature and humidity point P x It is the optimal control target temperature and humidity point.

[0135] Step S57: If M x >M x+1 , we can determine the temperature and humidity point P that is the current control target x Compared with the upper control target temperature and humidity point P x+1 More energy-saving, at this time, change the current control target temperature and humidity point to P x+1 , continue to P x+1 The corresponding total economic cost M x+1 and P x+2 The corresponding total economic cost M x+2 Compare until the smallest M is found x value, the smallest M x The current control target temperature and humidity point P corresponding to the value x It is the optimal control target temperature and humidity point.

[0136] In some embodiments of the present invention, the optimal control method for process air conditioning further includes:

[0137] Step S6: Determine the discounted efficiency based on the energy consumption corresponding to the current ambient temperature and humidity point x, and determine the optimal control target temperature and humidity point based on the discounted efficiency.

[0138] In one embodiment of the optimal control method for process air conditioning of the present invention, step S6 may specifically include:

[0139] Step S61: Calculate the current control target temperature and humidity point P by the following formula: xTotal standard coal K in steam mode x :

[0140] K x =(Q c / COP 冷 )*K 电 +(Q w / W)*K 汽 (8)

[0141] Among them, Q c Indicates the total energy consumption of the surface cooling valve in time t, COP 冷 Indicates the refrigeration coefficient of the refrigerator, Q w represents the total energy consumption of the heating valve in time t, W represents the calorific value of steam in steam heating mode, K 电 Indicates the preset electrical rebate coefficient, K 汽 Indicates the preset steam reduction coefficient.

[0142] Step S62: Calculate the current control target temperature and humidity point P using the following formula: x Total standard coal K in heat pump mode x :

[0143] K x =(Q c / COP 冷 )*K 电 +(Q w / COP 泵 )*K 电 (9)

[0144] Among them, COP 泵 Indicates the heating coefficient of the heat pump in heating mode.

[0145] Step S63: Calculate the current control target temperature and humidity point P according to formula (9) x Corresponding total standard coal K x , and the current control target temperature and humidity point P x The upper control target temperature and humidity point P x+1 Corresponding total standard coal K x+1 .

[0146] Step S64: If K x <K x+1 , then the current control target temperature and humidity point P x It is the optimal control target temperature and humidity point.

[0147] Step S65: If K x >K x+1 , we can determine the temperature and humidity point P that is the current control target x Compared with the upper control target temperature and humidity point P x+1More energy-saving, at this time, change the current control target temperature and humidity point to P x+1 , continue to P x+1 Corresponding total standard coal K x+1 and P x+2 The corresponding total economic cost K x+2 Compare until the smallest K is obtained x value, the smallest K x The current control target temperature and humidity point P corresponding to the value x It is the optimal control target temperature and humidity point.

[0148] Regarding energy consumption comparison, the present invention performs calculations from two perspectives: one comparing benefits based on economic expenditure, and the other determining benefits based on standard coal values. It should be noted that in one embodiment, the present invention may compare monetary benefits based solely on economic expenditure; in another embodiment, the present invention may compare standard coal benefits based solely on standard coal values; and in yet another embodiment, the present invention may compare comprehensive benefits based on a weighted summation of economic expenditure and standard coal values. This is not specifically limited in the present invention.

[0149] In some embodiments of the present invention, the optimal control method for process air conditioning further includes:

[0150] Step S7: If the current ambient temperature and humidity point x does not coincide with one of the control target temperature and humidity points on the boundary line, it is determined that there is no over-cooling, and after the current ambient temperature and humidity point x enters the controlled area A, the target temperature and humidity value P of the current ambient temperature and humidity point x is set to the lowest target temperature and humidity point P1 of the controlled area A.

[0151] For example, when point x enters the controlled area A and leaves the boundary between area A and high humidity working area ④, it completely enters the controlled area A. At this time, it is considered that there is no longer a dehumidification demand, and the target temperature and humidity value P is set back to the lowest temperature and humidity target value P1 of area A.

[0152] The optimal control method for process air conditioning provided by an embodiment of the present invention compares the energy consumption corresponding to the current ambient temperature and humidity point x with the energy consumption corresponding to the temperature and humidity point higher than the previous level control target when over-cooling occurs, and determines whether to perform temperature increase control at the current ambient temperature and humidity point x based on the energy consumption comparison result. The most energy-saving target temperature and humidity are obtained through real-time calculation, and the actual working condition output is determined according to the current dehumidification capacity, thereby preventing or reducing over-cooling caused by dehumidification and reducing energy waste; only the controlled temperature and humidity range needs to be obtained, and the winter and summer mode switching can be canceled; the target value is set during the temperature and humidity control process, and the actual control working condition is determined based on the target value. By finding and setting the optimal target value, it is helpful to quickly achieve the control target value, thereby improving the control capability and control efficiency of the process air conditioning.

[0153] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0154] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An optimal control method for process air conditioning, characterized in that: The steps include: Determine the working conditions of the process air conditioning; If it is a high humidity working condition, the temperature of the controlled area A is divided into N levels on the enthalpy-humidity diagram, and N points are taken on the boundary line of the controlled area A close to the high humidity working condition area as the control target temperature and humidity points; When the process air conditioner is switched from a high humidity condition to the controlled area A, whether there is over-cooling is determined based on whether the current ambient temperature and humidity point x coincides with one of the control target temperature and humidity points on the boundary line; If they coincide, it is determined that there is over-cooling. At this time, the energy consumption corresponding to the current ambient temperature and humidity point x is compared with the energy consumption corresponding to the lowest control target temperature and humidity point higher than the current ambient temperature and humidity point x. Based on the energy consumption comparison result, it is determined whether to perform temperature increase control at the current ambient temperature and humidity point x. When it is determined that there is overcooling, comparing the energy consumption corresponding to the current ambient temperature and humidity point x with the energy consumption corresponding to the lowest control target temperature and humidity point higher than the current ambient temperature and humidity point x, and determining whether to perform temperature increase control at the current ambient temperature and humidity point x based on the energy consumption comparison result, specifically includes: Step S41: Set the temperature of the initial ambient temperature and humidity point x to T0, the moisture content to H0, and the corresponding control target temperature and humidity point to P x ; Step S42: Calculate the current control target temperature and humidity point P using the following formula: x The total energy consumption of the heating valve in the following duration t is: Among them, Q w represents the total energy consumption of the heating valve in time t, C represents the heat capacity ratio of water, ΔT w Indicates the inlet and outlet water temperature difference of the heating valve, ρ w Indicates the density of water passing through the heating valve, V ω Indicates the water flow rate through the heating valve, A ω represents the cross-sectional area of ​​the heating valve, and t represents the heating duration; Step S43: Calculate the current control target temperature and humidity point P using the following formula: x The total energy consumption of the surface cooling valve in the duration t is: Among them, Q c represents the total energy consumption of the surface cooling valve in time t, C represents the heat capacity ratio of water, ΔT c Indicates the inlet and outlet water temperature difference of the surface cooling valve, ρ c Indicates the density of water passing through the surface cooling valve, V c Indicates the water flow rate through the surface cooling valve, A c represents the cross-sectional area of ​​the surface cooling valve, and t represents the duration; Step S44: Calculate the total energy consumption within the duration t using the following formula: Q x =Q w +Q c (3) Among them, Q x It represents the total energy consumption of the heating valve and the surface cooling valve in time t; Step S45: Calculate the total energy consumption Q at the initial ambient temperature and humidity point x within the duration t using formula (1)-formula (3): x ; Step S46: Calculate the upper level control target temperature and humidity point P of the initial environment temperature and humidity point x by formula (1)-formula (3) x+1 The total energy consumption Q during the duration t x+1 ; Step S47: Compare Q x and Q x+1 If the size of Q x+1 <Q x , then the upper level control target temperature and humidity point P x+1 The control target temperature and humidity point corresponding to the initial ambient temperature and humidity point x is P x More energy-efficient; Step S48: Let x = x + 1, and repeat steps S45 to S47 to calculate the current control target temperature and humidity point P. x The upper control target temperature and humidity point P x+1 The corresponding energy consumption Q x+1 , and compare the current control target temperature and humidity point P x Energy consumption Q x And the corresponding upper control target temperature and humidity point P x+1 Energy consumption Q x+1 , until the upper level controls the energy consumption Q of the target temperature and humidity point x+1 Greater than the energy consumption Q of the current control target temperature and humidity point x , then determine the current control target temperature and humidity point P x It is the optimal control target temperature and humidity point.

2. The optimal control method for process air conditioning according to claim 1, characterized in that: The controlled area A is an interval on the psychrometric diagram where the temperature is between the lower temperature limit T1 and the upper temperature limit T2, and the moisture content is between the lower relative humidity limit H1 and the upper relative humidity limit H2.

3. The optimal control method for process air conditioning according to claim 2, characterized in that: Under high humidity conditions, the temperature of the controlled area A is divided into N levels on the psychrometric diagram, and N points are taken on the boundary line of the controlled area A close to the high humidity condition area as the control target temperature and humidity points, specifically including: On the psychrometric chart, the temperature range between the lower temperature limit T1 and the upper temperature limit T2 of the controlled area A is divided into N sections from bottom to top, and the boundary line between the controlled area A and the high humidity working area is divided into N control target temperature and humidity points, namely P1, P2, P3, ..., P N , where the target temperature and humidity point P is controlled i The corresponding temperature is T i , the corresponding humidity is H i , where 1≤i≤N.

4. The optimal control method for process air conditioning according to claim 1, characterized in that: The optimal control method of the process air conditioner also includes: The economic cost is determined based on the energy consumption corresponding to the current ambient temperature and humidity point x, and the optimal control target temperature and humidity point is determined based on the economic cost, specifically including: Calculate the current control target temperature and humidity point P by the following formula x The economic cost of the cooling valve is shown in the following table: M c =Q c / COP 冷 *U (4) Among them, M c The total energy consumption Q of the surface cooling valve in time t c The economic cost, Q c Indicates the total energy consumption of the surface cooling valve in time t, COP 冷 represents the cooling coefficient of the refrigerator, and U represents the unit price of electricity; Calculate the current control target temperature and humidity point P by the following formula x Economic cost of lower heating valve in steam mode M w : M w =(Q w / W / R)*Y (5) Among them, Q w represents the total energy consumption of the heating valve in time t, W and R represent the steam calorific value and steam-gas ratio in steam heating mode, and Y represents the unit price of natural gas; Calculate the current control target temperature and humidity point P by the following formula x Economic cost of lower heating valve in heat pump mode M w : M w =Q w / COP 泵 *U (6) Among them, COP 泵 It represents the heating coefficient of the heat pump in heating mode, and U represents the unit price of electricity; Calculate the current control target temperature and humidity point P by the following formula x The total economic cost M of the cooling valve and heating valve in the table below x : M x =M c +M w (7) Among them, M c Calculated by formula (4), M w Calculated by formula (5) or (6); According to formula (7), calculate the current control target temperature and humidity point P x The corresponding total economic cost M x , and the current control target temperature and humidity point P x The upper control target temperature and humidity point P x+1 The corresponding total economic cost M x+1 ; If M x <M x+1 , then the current control target temperature and humidity point P x To optimally control the target temperature and humidity points; If M x >M x+1 , we can determine the temperature and humidity point P that is the current control target x Compared with the upper control target temperature and humidity point P x+1 More energy-saving, at this time, change the current control target temperature and humidity point to P x+1 , continue to P x+1 The corresponding total economic cost M x+1 and P x+2 The corresponding total economic cost M x+2 Compare until the smallest M is found x value, the smallest M x The current control target temperature and humidity point P corresponding to the value x It is the optimal control target temperature and humidity point.

5. The optimal control method for process air conditioning according to claim 1, characterized in that: The optimal control method of the process air conditioner also includes: The discounted benefit is determined based on the energy consumption corresponding to the current ambient temperature and humidity point x, and the optimal control target temperature and humidity point is determined based on the discounted benefit, specifically including: Calculate the current control target temperature and humidity point P by the following formula x Total standard coal K in steam mode x : K x =(Q c / COP 冷 )*K 电 +(Q w / W)*K 汽 (8) Among them, Q c Indicates the total energy consumption of the surface cooling valve in time t, COP 冷 Indicates the refrigeration coefficient of the refrigerator, Q w represents the total energy consumption of the heating valve in time t, W represents the calorific value of steam in steam heating mode, K 电 Indicates the preset electrical rebate coefficient, K 汽 Indicates the preset steam reduction coefficient; Calculate the current control target temperature and humidity point P by the following formula x Total standard coal K in heat pump mode x : K x =(Q c / COP 冷 )*K 电 +(Q w / COP 泵 )*K 电 (9) Among them, COP 泵 Indicates the heating coefficient of the heat pump in heating mode; According to formula (9), calculate the current control target temperature and humidity point P x Corresponding total standard coal K x , and the current control target temperature and humidity point P x The upper control target temperature and humidity point P x+1 Corresponding total standard coal K x+1 ; If K x <K x+1 , then the current control target temperature and humidity point P x To optimally control the target temperature and humidity points; If K x >K x+1 , we can determine the temperature and humidity point P that is the current control target x Compared with the upper control target temperature and humidity point P x+1 More energy-saving, at this time, change the current control target temperature and humidity point to P x+1 , continue to P x+1 Corresponding total standard coal K x+1 and P x+2 The corresponding total economic cost K x+2 Compare until the smallest K is obtained x value, the smallest K x The current control target temperature and humidity point P corresponding to the value x It is the optimal control target temperature and humidity point.

6. The optimal control method for process air conditioning according to claim 5, characterized in that: The optimal control method of the process air conditioner also includes: If the current ambient temperature and humidity point x does not coincide with one of the control target temperature and humidity points on the boundary line, it is determined that there is no over-cooling, and after the current ambient temperature and humidity point x enters the controlled area A, the target temperature and humidity value P of the current ambient temperature and humidity point x is set to the lowest target temperature and humidity point P1 of the controlled area A.

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