EC-based fan variable air volume combined air conditioner control system

Abstract

The utility model relates to the technical field of heating and ventilation automation control, in particular to an EC-based fan variable air volume combined type air conditioner control system which comprises a ventilation channel provided with a first air inlet end, a second air inlet end and an air outlet end, the first air inlet end is used for introducing fresh air, and the second air inlet end is used for introducing fresh air; the second air inlet end is connected to an air return pipeline of an air supply place; and the cooling component is arranged in the ventilation channel. By monitoring the enthalpy values of the air inlet side of the cooling component, the air supply pipeline and the air supply place, whether cooling capacity conveying needs to be increased or decreased indoors is judged, and when the cooling capacity needs to be increased, the enthalpy difference between the air inlet side of the cooling component and the air supply pipeline is increased, so that the cooling capacity of the system is increased; and meanwhile, only the opening degree of the regulating valve or the frequency of the centrifugal fan is regulated, so that the enthalpy value of the tail end of the system is accurately controlled along with the change of the load, and the energy-saving operation of the system is ensured while the comfortable effect of the environment is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of heating and ventilation automation control, in particular to a variable air volume combined air conditioning control system based on an EC fan. Background Art

[0002] In the existing rail transit industry, most of the air conditioners at the end of subway stations continue to use ordinary single or variable frequency motors, which are noisy and have low energy efficiency. For long-term operation applications such as stations, there is huge room for energy saving. In addition, based on seasonal changes and changes in passenger flow, there is also a lot of room for energy saving in the system air volume and system load required for the station hall and platform.

[0003] The current single-speed fan cannot adjust the air volume, and it is not necessarily the rated air volume. The temperature can only be adjusted through the surface cooling valve. Under partial load, energy-saving control based on air volume changes cannot be achieved. The variable frequency fan can adjust the constant air volume based on the rated air volume, and the surface cooling valve and frequency are controlled at the same time, but it lacks comfort and is prone to overcooling or overheating. Utility Model Content

[0004] In view of the technical problems existing in the air conditioning control system in the prior art, the first aspect of the utility model proposes a technical solution, a variable air volume combined air conditioning control system based on an EC fan, comprising:

[0005] A ventilation channel, wherein the ventilation channel is provided with a first air inlet end, a second air inlet end and an air outlet end, wherein the first air inlet end is used to receive fresh air, and the second air inlet end is connected to a return air duct of an air supply location;

[0006] A cooling component is arranged in the ventilation channel and between the air inlet and the air outlet. The cooling component is provided with a regulating valve, and the regulating valve is used to adjust the flow rate of the refrigerant in the cooling component;

[0007] A centrifugal fan is arranged in the ventilation channel and in front of the air outlet, and is used to supply air to the air outlet;

[0008] An air supply duct, a first end of which is connected to the air outlet end of the ventilation channel, and a second end of which is connected to the air supply location;

[0009] An air volume sensor is arranged in the air supply duct and is used to obtain the size of the air volume Q in the air supply duct;

[0010] Enthalpy value collection component, used to collect the mixed air enthalpy value H on the air inlet side of the cooling component 混 , the air outlet enthalpy value H in the air supply duct 出 And the indoor enthalpy value H in the air supply area 室 ;

[0011] The controller is electrically connected to the enthalpy value collecting component, the air volume sensor, the centrifugal fan and the regulating valve, and is used to control the operating frequency of the centrifugal fan and the opening of the regulating valve.

[0012] Preferably, the controller is used to adjust the frequency of the centrifugal fan up or down.

[0013] Preferably, the controller is used to adjust the opening of the regulating valve to increase or decrease.

[0014] Preferably, the regulating valve is the first control object of the controller, the centrifugal fan is the second control object of the controller, and the controller can only adjust one of the first control object or the second control object at the same time.

[0015] Preferably, the enthalpy value collecting component includes a first temperature and humidity sensor, a second mixed humidity sensor and a third temperature and humidity sensor.

[0016] Preferably, the first temperature and humidity sensor is arranged at the air inlet side of the cooling component, and is used to collect the dry bulb temperature and relative humidity at the air inlet side of the cooling component to calculate the mixed air enthalpy value H 混 .

[0017] Preferably, the second mixed humidity sensor is arranged in the air supply duct and is used to collect the dry bulb temperature and relative humidity in the air supply duct to calculate the outlet air enthalpy value H 出 .

[0018] Preferably, the third temperature and humidity sensor is arranged in the air supply place and is used to collect the dry-bulb temperature and relative humidity in the air supply place to calculate the indoor enthalpy value H 室 .

[0019] Preferably, the cooling component comprises a surface cooling section of the fresh air system, the surface cooling section comprises a cooling coil, and the regulating valve is used to adjust the flow rate of the refrigerant in the cooling coil.

[0020] Compared with the prior art, the advantages of the utility model are:

[0021] The utility model determines whether the indoor cooling capacity needs to be increased or decreased by monitoring the enthalpy values ​​at the air inlet side of the cooling component, in the air supply duct and in the air supply place. When the cooling capacity needs to be increased, the enthalpy difference between the air inlet side of the cooling component and in the air supply duct is increased to increase the cooling capacity of the system. Meanwhile, only the opening of the regulating valve or the frequency of the centrifugal fan is adjusted to achieve precise control of the terminal enthalpy value of the system changing with the load, so as to achieve a comfortable environment while ensuring the energy-saving operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are not intended to be drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the utility model will be described by way of example and with reference to the accompanying drawings, in which:

[0023] Figure 1 It is a schematic diagram of a variable air volume combined air conditioning control system based on an EC fan shown in the present utility model. DETAILED DESCRIPTION

[0024] In order to better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0025] This application aims to adjust the water valve opening first under the minimum air volume of the system based on energy efficiency comparison, control the outlet air enthalpy value after surface cooling, establish enthalpy difference, and adjust the total cooling capacity of the unit; when the water valve is opened to the maximum opening and the total cooling capacity of the unit is insufficient, the EC fan frequency is gradually increased to increase the total cooling capacity of the unit, ensuring that the terminal system produces accurate cooling capacity under the optimal energy efficiency, so that the terminal load is accurately controlled.

[0026]

EC fan variable air volume combined air conditioning control system

[0027] like Figure 1 As shown, the first aspect of the utility model proposes a technical solution, a variable air volume combined air conditioning control system based on an EC fan, including a ventilation channel 10, a cooling component 20, a centrifugal fan 30, an air supply duct 40, an air volume sensor 41, an enthalpy value collection component and a controller 70.

[0028] Among them, EC fan refers to a centrifugal fan.

[0029] The ventilation channel 10 is provided with a first air inlet end 11 , a second air inlet end 12 and an air outlet end 13 . The first air inlet end 10 is used for receiving fresh air, and the second air inlet end 12 is connected to a return air duct 61 of an air supply location 60 .

[0030] Preferably, a filter section 14 is provided between the first air inlet end 11 and the second air inlet end 12 for filtering the fresh air entering from the first air inlet end 11 to ensure the cleanliness of the air supplied by the system.

[0031] In this way, the fresh air enters the ventilation passage 10 together with the return air from the air supply location 60 , and after being cooled by the cooling component 20 and driven by the centrifugal fan 30 , enters the air supply location 60 from the air outlet end 13 .

[0032] The cooling component 20 is disposed in the ventilation channel 10 and is located between the air inlet end and the air outlet end 13 . A regulating valve 21 is provided on the cooling component 20 . The regulating valve 21 is used to adjust the flow rate of the refrigerant in the cooling component 20 .

[0033] In an optional embodiment, the cooling component 20 includes a surface cooling section of the fresh air system, the surface cooling section includes a cooling coil, and the regulating valve 21 is used to adjust the flow of the refrigerant in the cooling coil. In this way, the temperature of the airflow passing through the surface cooling section can be changed by adjusting the opening of the regulating valve 21 through the controller 70.

[0034] The centrifugal fan 30 is disposed in the ventilation passage 10 and in front of the air outlet 13 for supplying air to the air outlet 13 . The controller 70 determines the amount of air supplied to the air outlet 13 by controlling the frequency of the centrifugal fan 30 .

[0035] Furthermore, a first end of the air supply duct 40 is connected to the air outlet end 13 of the ventilation channel 10, and a second end is connected to the air supply place 60; an air volume sensor 41 is arranged in the air supply duct 40 to obtain the size of the air volume Q in the air supply duct 40, and the controller 70 can control the frequency of the centrifugal fan 30 according to the size of the air volume Q in the air supply duct 40 detected by the air volume sensor 41.

[0036] It can be understood that the regulating valve 21 is the first control object of the controller 70, and the centrifugal fan 30 is the second control object of the controller 70. The controller 70 can only adjust one of the first control object or the second control object at the same time, that is, adjust the two control objects sequentially.

[0037] The enthalpy value collection component is used to collect the mixed air enthalpy value H on the air inlet side of the cooling component. 混 , the air outlet enthalpy value H in the air supply duct 出 And the indoor enthalpy value H in the air supply area 室 The controller 70 is electrically connected to the enthalpy value collection component, the air volume sensor 41 , the centrifugal fan 30 , and the regulating valve 21 .

[0038] The controller 70 can control the opening of the regulating valve or the frequency of the centrifugal fan 30 according to the enthalpy values ​​of each area collected by the enthalpy value collection component and the air volume Q in the air supply duct. For example, the opening of the regulating valve can be controlled to increase / decrease or the frequency of the centrifugal fan 30 can be controlled to increase / decrease.

[0039] The above air conditioning control system can be used as follows:

[0040] The priority of regulating the opening of the regulating valve 21 and the frequency of the centrifugal fan 30 is set to be when the indoor enthalpy value H 室When the indoor enthalpy value H of the air supply place 60 is greater than the preset value, the priority of the opening adjustment of the regulating valve 21 is greater than the frequency adjustment of the centrifugal fan 30. 室 When the frequency is less than the preset value, the frequency regulation priority of the centrifugal fan 30 is higher than the opening regulation of the regulating valve 21 .

[0041] It should be understood that the faster the frequency adjustment of the centrifugal fan 30 is, the greater its energy consumption is. Therefore, the opening of the regulating valve 21 is preferably used to control the indoor enthalpy value H 室 The size of the house can be adjusted to achieve Feng Shui linkage and achieve the purpose of energy saving.

[0042] like Figure 1 As shown, the enthalpy value collection component includes a first temperature and humidity sensor 51, a second mixed air humidity sensor 52 and a third temperature and humidity sensor 53; the first temperature and humidity sensor 51 is arranged on the air inlet side of the cooling component 20, and is used to collect the dry bulb temperature and relative humidity on the air inlet side of the cooling component 20 to calculate the mixed air enthalpy value H 混 The second mixed humidity sensor 52 is disposed in the air supply duct 40 and is used to collect the dry bulb temperature and relative humidity in the air supply duct 40 to calculate the outlet enthalpy value H 出 The third temperature and humidity sensor 53 is disposed in the air supply location 60 and is used to collect the dry-bulb temperature and relative humidity in the air supply location 60 to calculate the indoor enthalpy value H 室 .

[0043] It should be understood that according to the total cooling capacity of the unit = air supply volume Q / 3600*1.2*(mixed air enthalpy H 混 -Outlet air enthalpy H 出 ) It can be seen that the opening of the regulating valve 21 and the frequency of the centrifugal fan 30 will affect the change of the total cooling capacity of the unit.

[0044] It should be understood that the temperature and humidity of the air supply place 60 should be set within a predetermined range, and the ventilation frequency of the system is also set within a predetermined range. In an optional embodiment, the temperature and humidity range of the air supply place 60 is defined as between C1 and C2, and the corresponding upper limit of the indoor enthalpy value is Hh and the lower limit is Hl. The range of the ventilation frequency is defined as between D1 and D2, and the upper limit Qh and the lower limit Ql of the system air supply volume Q are corresponding to the upper and lower limits of the ventilation frequency;

[0045] When the air supply volume reaches Q1, the controller sequentially controls the opening of the regulating valve 21 and the frequency of the centrifugal fan 30 to make the indoor enthalpy value H 室 Lower than the upper limit of indoor enthalpy value Hh.

[0046] Since the opening degree of the regulating valve 21 and the frequency of the centrifugal fan 30 can both affect the total cooling capacity of the unit, and the centrifugal fan 30 consumes more energy when operating at a high frequency, therefore, the opening degree of the regulating valve 21 is adjusted preferentially. When the opening degree of the regulating valve 21 is maximized and sufficient cooling capacity still cannot be ensured, the frequency of the centrifugal fan 30 is adjusted.

[0047] In an alternative embodiment, when the system is started and the cooling capacity produced by the system does not meet the demand, the controller 70 controls the frequency of the centrifugal fan 30 according to the air supply volume detected by the air volume sensor 41 to make the air supply volume reach the lower limit Ql. When the third temperature and humidity sensor 53 detects that the indoor enthalpy value H 室 > Hh and before the opening degree of the regulating valve 21 is less than 100%, the controller 70 controls the opening degree of the regulating valve 21 to make the indoor enthalpy value H 室 < Hh.

[0048] Furthermore, when the opening degree of the regulating valve 21 is equal to 100%, the controller 70 controls the frequency of the centrifugal fan 30 to make the indoor enthalpy value H 室 < Hh.

[0049] After the cooling capacity produced by the system meets the demand and there is an excess of cooling capacity, the frequency of the centrifugal fan 30 is preferentially reduced. Optionally, when the third temperature and humidity sensor 53 detects that the indoor enthalpy value H 室 < Hh, the controller 70 controls the frequency of the centrifugal fan 30 to decrease, making the indoor enthalpy value H 室 approach Hh.

[0050] Furthermore, when the third temperature and humidity sensor 53 detects that the indoor enthalpy value H 室 < Hh and after the air supply volume is lower than the lower limit Ql of the air supply volume, the controller 70 controls the opening degree of the regulating valve 21 to decrease.

[0051] In a specific usage method of the above air conditioning control system, the following steps are included:

[0052] Step 1: Set the indoor target temperature range and the ventilation rate range, and calculate the upper limit Hh and the lower limit Hl of the indoor enthalpy value, and the upper limit Qh and the lower limit Ql of the system air supply volume corresponding to the upper and lower limits of the ventilation rate according to the set indoor target temperature range and ventilation rate range;

[0053] Step 2: Collect the enthalpy values of each area and the air volume Q in the air supply duct in real time, and control the operating frequency of the centrifugal fan 30 to make its air supply volume reach the lower limit Ql of the air supply volume;

[0054] Step 3: Adjust the opening degree of the regulating valve 21 and the frequency of the centrifugal fan 30 according to the change of the indoor enthalpy value H 室 to make the indoor enthalpy value H 室 fall within the preset range;

[0055] Among them, if the indoor enthalpy value H 室 If the indoor enthalpy value is greater than the upper limit Hh, the opening of the regulating valve 21 is increased to 100% first. 室 If the indoor enthalpy value Hh is still greater than the upper limit of the indoor enthalpy value, the frequency of the centrifugal fan 30 is increased until the air supply volume reaches the upper limit of the air supply volume Qh; if the indoor enthalpy value Hh of the air supply place 60 is 室 If the indoor enthalpy value is less than the lower limit H1, the frequency of the centrifugal fan 30 is preferentially reduced until the air supply volume reaches the lower limit Q1. 室 If the indoor enthalpy value is still less than the lower limit H1, the opening of the regulating valve 21 is further reduced until it reaches 0%.

[0056] Preferably, in step 2, the enthalpy value of the predetermined area is calculated by obtaining the dry-bulb temperature and relative humidity in the predetermined area, and the predetermined area includes the air inlet side area of ​​the cooling component, the inside of the air supply duct and the air supply place.

[0057] In a specific embodiment, after the unit is turned on, the controller 70 monitors the air volume sensor 41, gradually loads the frequency of the centrifugal fan 30, and gives priority to ensuring the lower limit Q1 of the system air volume. 室 When the indoor enthalpy value is higher than the upper limit Hh, the regulating valve 21 is opened first to reduce the outlet air enthalpy value H 出 , increasing the total cooling capacity of the unit, thereby increasing the indoor enthalpy H 室 Gradually lower than the upper limit of indoor enthalpy value Hh. When the opening of regulating valve 21 is 100% and the mixed air enthalpy value H 混 If the indoor enthalpy value is still higher than the upper limit Hh, the controller 70 gradually increases the frequency of the centrifugal fan 30 through communication, so that the air supply volume detected by the air volume sensor 41 gradually increases until the system air supply volume reaches the upper limit Qh and the total cooling capacity of the unit reaches the upper limit. 室 When the indoor enthalpy value is lower than the upper limit Hh, the frequency of the centrifugal fan 30 is preferentially reduced until the system air supply volume reaches the lower limit Ql. If the indoor enthalpy value H detected by the third temperature and humidity sensor 53 is 室 When it is still lower than the upper limit Hh of the indoor enthalpy value, the opening of the regulating valve 21 is gradually reduced until the opening is closed to 0% and the total cooling capacity of the unit reaches the lower limit.

[0058] In combination with the above embodiments, the utility model monitors the enthalpy values ​​at the air inlet side of the cooling component, in the air supply duct, and in the air supply place to determine whether the indoor cooling capacity needs to be increased or reduced. When the cooling capacity needs to be increased, the enthalpy difference between the air inlet side of the cooling component and the air supply duct is increased to increase the cooling capacity of the system. At the same time, only the opening of the regulating valve or the frequency of the centrifugal fan is adjusted to accurately control the change of the enthalpy value at the end of the system with the load change, so that the environment can achieve a comfortable effect while ensuring the energy-saving operation of the system.

[0059] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A variable air volume combined air conditioning control system based on EC fans, characterized in that: include: A ventilation channel (10), the ventilation channel (10) being provided with a first air inlet end (11), a second air inlet end (12) and an air outlet end (13), the first air inlet end (11) being used to receive fresh air, and the second air inlet end (12) being connected to a return air duct (61) of an air supply location (60); A cooling component (20) is arranged in the ventilation channel (10) and is located between the air inlet end and the air outlet end (13); a regulating valve (21) is provided on the cooling component (20); the regulating valve (21) is used to regulate the flow rate of the refrigerant in the cooling component (20); A centrifugal fan (30) is arranged in the ventilation passage (10) and in front of the air outlet (13), and is used to supply air to the air outlet (13); An air supply duct (40), a first end of which is connected to the air outlet end (13) of the ventilation channel (10), and a second end of which is connected to the air supply location (60); An air volume sensor (41) is arranged in the air supply duct (40) and is used to obtain the size of the air volume Q in the air supply duct (40); Enthalpy value collection component, used to collect the mixed air enthalpy value H on the air inlet side of the cooling component 混 , the air outlet enthalpy value H in the air supply duct 出 And the indoor enthalpy value H in the air supply area 室 ; A controller (70) is electrically connected to the enthalpy value collection component, the air volume sensor (41), the centrifugal fan (30), and the regulating valve (21), and is used to control the operating frequency of the centrifugal fan (30) and the opening of the regulating valve (21).

2. The EC fan variable air volume combined air conditioning control system according to claim 1 is characterized in that: The controller (70) is used to adjust the frequency of the centrifugal fan (30) to increase or decrease.

3. The EC fan variable air volume combined air conditioning control system according to claim 1, characterized in that: The controller (70) is used to adjust the opening of the regulating valve (21) to increase or decrease.

4. The EC fan variable air volume combined air conditioning control system according to claim 2 or 3, characterized in that: The regulating valve (21) is a first control object of the controller (70), and the centrifugal fan (30) is a second control object of the controller (70). The controller (70) can only regulate one of the first control object or the second control object at the same time.

5. The EC fan variable air volume combined air conditioning control system according to claim 1, characterized in that: The enthalpy value collection component comprises a first temperature and humidity sensor (51), a second mixed humidity sensor (52) and a third temperature and humidity sensor (53).

6. The EC fan variable air volume combined air conditioning control system according to claim 5, characterized in that: The first temperature and humidity sensor (51) is arranged on the air inlet side of the cooling component (20) and is used to collect the dry-bulb temperature and relative humidity on the air inlet side of the cooling component (20) to calculate the mixed air enthalpy value H 混 .

7. The EC fan variable air volume combined air conditioning control system according to claim 5, characterized in that: The second mixed humidity sensor (52) is arranged in the air supply duct (40) and is used to collect the dry-bulb temperature and relative humidity in the air supply duct (40) to calculate the outlet air enthalpy value H 出 .

8. The EC fan variable air volume combined air conditioning control system according to claim 5, characterized in that: The third temperature and humidity sensor (53) is arranged in the air supply location (60) and is used to collect the dry-bulb temperature and relative humidity in the air supply location (60) to calculate the indoor enthalpy value H 室 .

9. The EC fan variable air volume combined air conditioning control system according to claim 1, characterized in that: The cooling component (20) comprises a surface cooling section of a fresh air system, the surface cooling section comprises a cooling coil, and the regulating valve (21) is used to regulate the flow of the refrigerant in the cooling coil.

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