Central air conditioning energy storage device and control method thereof

Abstract

The application discloses a central air conditioner energy storage device and a control method thereof, and relates to the technical field of energy storage control. The device comprises an original machine room water inlet and outlet pipeline, an energy storage module and a water tank. The original machine room water inlet and outlet pipeline comprises a user backwater side, a user water inlet side, a machine room backwater side, a machine room water outlet side and a first valve. The energy storage module comprises a plate heat exchanger, a first water pump, a second water pump, an F1A valve, an F1B valve, an F2A valve, an F2B valve and an industrial computer. The industrial computer is used for controlling the two water pumps and the five valves according to the pressure difference of the primary side of the plate heat exchanger, the pressure difference of the secondary side, the primary side water inlet temperature, the secondary side water inlet temperature, the primary side water outlet temperature and the secondary side water outlet temperature, the water temperature at the first opening of the water tank, the water temperature at the second opening of the water tank, the water outlet temperature of the machine room water outlet side and the water inlet temperature of the user water inlet side. The application can save cost.

Description

Technical Field

[0001] This invention relates to the field of energy storage control technology, and in particular to a central air conditioning energy storage device and its control method. Background Technology

[0002] In new construction and energy-saving renovation projects of building HVAC systems, in order to improve unit efficiency, it is necessary to increase the unit's water capacity and install energy storage devices. However, pressurized water tanks are expensive, which increases costs. On the other hand, utilizing off-peak electricity prices at night for "cold storage" can alleviate the load pressure on the power grid and save users money. However, traditional ice storage systems are expensive and have high requirements for system design and construction. In particular, in the renovation of existing projects, it is necessary to remove the original pipelines, resulting in huge waste and high costs. Summary of the Invention

[0003] The purpose of this invention is to provide a central air conditioning energy storage device and its control method, which can save costs.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] A central air conditioning energy storage device, comprising:

[0006] The original equipment room includes inlet and outlet water pipes, energy storage modules, and a water tank; the original equipment room inlet and outlet water pipes include: user return water side, user inlet water side, equipment room return water side, equipment room outlet water side, and a first valve; the energy storage module includes: a plate heat exchanger, a first water pump, a second water pump, valves F1A, F1B, F2A, and F2B, and an industrial control computer;

[0007] The first valve is installed between the user's water inlet side and the user's water return side; the machine room water outlet side and the user's water inlet side are connected by a first pipe; the first pipe is connected to the primary side inlet of the plate heat exchanger through a primary side water inlet pipe; the first pipe is connected to the primary side outlet of the plate heat exchanger through a primary side water outlet pipe; and the first water pump is installed on the primary side water inlet pipe.

[0008] The secondary side inlet of the plate heat exchanger is connected to the first opening of the water tank via a secondary side inlet pipe, and the secondary side outlet of the plate heat exchanger is connected to the secondary side inlet pipe via a secondary side outlet pipe; valve F2A is installed on the secondary side outlet pipe; the second opening of the water tank is connected to the secondary side inlet pipe via an outlet pipe, and valve F2B is installed on the outlet pipe; the outlet pipe is connected to the secondary side outlet pipe via a bypass pipe, and valve F1A is installed on the bypass pipe; valve F2A is located between the first and second interfaces, valve F1B is located between the first and third interfaces, and the second water pump is located between the third interface and the secondary side inlet of the plate heat exchanger; the first interface is the connection point between the secondary side inlet pipe and the secondary side outlet pipe; the second interface is the connection point between the bypass pipe and the secondary side outlet pipe; and the third interface is the connection point between the outlet pipe and the secondary side inlet pipe.

[0009] The industrial control computer is connected to the first water pump, the second water pump, the F1A valve, the F1B valve, the F2A valve, the F2B valve, and the first valve, respectively. The industrial control computer is used to control the first water pump, the second water pump, the F1A valve, the F1B valve, the F2A valve, the F2B valve, and the first valve based on the pressure difference on the primary side and the pressure difference on the secondary side of the plate heat exchanger, the primary side inlet water temperature, the secondary side inlet water temperature, the primary side outlet water temperature, the secondary side outlet water temperature, the water temperature at the first opening of the water tank, the water temperature at the second opening of the water tank, the outlet water temperature on the machine room outlet side, and the inlet water temperature on the user inlet side.

[0010] A control method for a central air conditioning energy storage device, applied to the aforementioned central air conditioning energy storage device, the control method comprising:

[0011] Determine whether the current moment is within a peak / valley period to obtain the first judgment result;

[0012] If the first judgment result is negative, the outlet water temperature on the machine room outlet side is set as the first temperature. If the measured outlet water temperature on the machine room outlet side is equal to the first temperature and the machine room load rate is equal to the first load rate threshold, then the online energy storage mode is entered. If the difference between the water temperature at the first opening of the water tank and the measured outlet water temperature on the machine room outlet side is equal to the first temperature difference threshold, and the machine room load rate is less than the first load rate threshold, then the online energy release mode is entered. The online energy storage mode is as follows: open valves F1A and F1B, close valves F2A and F2B, and execute pump energy storage mode, then update the current time and enter the next time. The online energy release mode is as follows: close the machine room, open valves F2A and F2B, then close valves F1A and F1B, and execute pump energy release mode, then update the current time and enter the next time.

[0013] If the first judgment result is yes, then if the water temperature at the second opening of the water tank is equal to the water tank temperature setting threshold and the air conditioner is on, then the peak-valley cooling mode is implemented; if the water temperature at the second opening of the water tank is greater than the water tank temperature setting threshold, then the outlet water temperature on the machine room outlet side is set to the second temperature, and the peak-valley energy storage mode is entered until the difference between the water temperature at the first opening of the water tank and the measured outlet water temperature on the machine room outlet side is equal to the first temperature difference threshold, and the machine room load rate is equal to the first load rate threshold, then the machine room is shut down; the second temperature is less than the first temperature; the peak-valley energy storage mode is as follows: if the air conditioner is on, then the first valve is opened and the pump energy storage mode is executed; if the air conditioner is off, then the first valve is closed and the pump energy storage mode is executed, and then the current time is updated to enter the next time; the peak-valley cooling mode is as follows: the pump energy release mode is executed until the water temperature at the second opening of the water tank is equal to the water tank temperature setting threshold, then the first water pump and the second water pump are shut down, and then the current time is updated to enter the next time.

[0014] The pump energy storage mode is as follows:

[0015] The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and a preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the user's inlet side, the inlet water temperature on the primary side of the plate heat exchanger, and a preset second-level PID trend principle. Finally, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the primary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and a preset third-level PID trend principle. The operating conditions are either cooling or heating.

[0016] The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-stage PID trend principle; then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the primary side of the plate heat exchanger, and the preset five-stage PID trend principle.

[0017] The pump energy release mode is as follows:

[0018] The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-level PID trend principle. Then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the secondary side of the plate heat exchanger, and the preset six-level PID trend principle.

[0019] The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and the preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the secondary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and the preset seventh-level PID trend principle.

[0020] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: the present invention does not require large-scale modifications to the original pipeline, nor does it affect the normal operation of the original system, thus saving costs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 The structural diagram of the central air conditioning energy storage device provided by the present invention;

[0023] Figure 2 This is a graph showing the temperature change over time.

[0024] Figure 3 This is a graph showing the change in unit load rate over time.

[0025] Figure 4 Preset secondary PID trend principle diagram;

[0026] Figure 5 A pre-defined three-level PID trend diagram;

[0027] Figure 6 The operating logic diagram of the first water pump in pump storage mode;

[0028] Figure 7 The preset fifth-level PID trend principle diagram;

[0029] Figure 8 The operating logic diagram of the second water pump in pump storage mode;

[0030] Figure 9 This is the operation logic diagram of the second water pump in the pump energy release mode;

[0031] Figure 10 This is the operation logic diagram of the first water pump in the pump energy release mode.

[0032] Symbol explanation:

[0033] First pressure sensor - P1, Second pressure sensor - P2, Third pressure sensor - P3, Fourth pressure sensor - P4, First temperature sensor - T1, Second temperature sensor - T2, Third temperature sensor - T3, Fourth temperature sensor - T4, Fifth temperature sensor - T5, Sixth temperature sensor - T6, Seventh temperature sensor - T7, Eighth temperature sensor - T8, Ninth temperature sensor - T9, Tenth temperature sensor - T10, Valve F1A - F1A, Valve F1B - F1B, Valve F2A - F2A, Valve F2B - F2B. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] This invention discloses a central air conditioning energy storage device, including a set of "non-destructive installation" energy storage modules. This invention does not require large-scale modifications to the original piping and will not affect the normal operation of the original system, while also achieving energy saving and environmental protection. The central air conditioning energy storage device is as follows: Figure 1 As shown:

[0037] A first valve is installed between the user's inlet and return water sides; the machine room outlet and the user's inlet are connected by a first pipe; the first pipe is connected to the primary inlet of the plate heat exchanger via a primary inlet pipe; the first pipe is connected to the primary outlet of the plate heat exchanger via a primary outlet pipe; a first water pump is installed on the primary inlet pipe; the secondary inlet of the plate heat exchanger is connected to the first opening of the water tank via a secondary inlet pipe; the secondary outlet of the plate heat exchanger is connected to the first opening of the water tank via a secondary outlet pipe. Water pipes are connected; valve F2A is installed on the secondary side outlet pipe; the second opening of the water tank is connected to the secondary side inlet pipe through the outlet pipe, and valve F2B is installed on the outlet pipe; the outlet pipe is connected to the secondary side outlet pipe through a bypass pipe, and valve F1A is installed on the bypass pipe; valve F2A is located between the first and second interfaces; valve F1B is located between the first and third interfaces; the second water pump is located at the third interface and the plate heat exchanger. Between the secondary side inlets; the first interface is where the secondary side inlet pipe connects to the secondary side outlet pipe; the second interface is where the bypass pipe connects to the secondary side outlet pipe; the third interface is where the outlet pipe connects to the secondary side inlet pipe; the industrial control computer is connected to the first water pump, the second water pump, valves F1A, F1B, F2A, F2B, and the first valve; the industrial control computer is used to calculate the pressure difference between the primary and secondary sides of the plate heat exchanger. The inlet water temperature, secondary inlet water temperature, primary outlet water temperature, secondary outlet water temperature, water temperature at the second opening of the water tank, water temperature at the second opening of the water tank, water temperature at the outlet of the machine room, and water temperature at the inlet of the user control the first water pump, the second water pump, valves F1A, F1B, F2A, F2B, and the first valve. The inlet and outlet of the water tank will change due to the different energy storage and energy release, so there is no limit to the inlet and outlet here.

[0038] In practical applications, the first pressure sensor P1 is positioned between the first water pump and the primary side inlet of the plate heat exchanger; the second temperature sensor T2 is positioned between the first sensor and the primary side inlet of the plate heat exchanger; the second pressure sensor P2 is positioned between the primary side outlet of the plate heat exchanger and the fourth interface; the third temperature sensor T3 is positioned between the second pressure sensor P2 and the primary side outlet of the plate heat exchanger; the third pressure sensor P3 is positioned between the second water pump and the secondary side inlet of the plate heat exchanger; the sixth temperature sensor T6 is positioned between the second water pump and the third pressure sensor P3; the fourth pressure sensor P4 is positioned between the second interface and the secondary side outlet of the plate heat exchanger; and the seventh temperature sensor T7 is positioned between the fourth pressure sensor P1 and the fourth pressure sensor P2. The first temperature sensor T1 is located between the water outlet side of the machine room and the fifth interface; the fourth temperature sensor T4 is located between the fourth interface and the fifth interface; the fifth temperature sensor T5 is located between the fourth interface and the user's water inlet side; the eighth temperature sensor T8 is located between the first interface and the first opening of the water tank; the ninth temperature sensor T9 is located between the second opening of the water tank and the F2B valve; and the tenth temperature sensor T10 is located at the second opening of the water tank. The fourth interface is where the primary side water outlet pipe connects to the first pipe, and the fifth interface is where the primary side water inlet pipe connects to the first pipe. Among them, the fourth temperature sensor T4 and the ninth temperature sensor T9 do not participate in control but mainly play a monitoring role.

[0039] Figure 1 The area within frame A contains the original water inlet and outlet pipes for the machine room. An electric on / off valve (first valve) will be added to the original pipes. Figure 1 The diagram shows valve 1, first temperature sensor T1, fourth temperature sensor T4 and fifth temperature sensor T5, and meter A for detecting the unit's operating load rate.

[0040] The energy storage module provided by this invention, which allows for "non-destructive installation," is located within frame B. It is equipped with a first pressure sensor P1, a second pressure sensor P2, a third pressure sensor P3, a fourth pressure sensor P4, a third temperature sensor T3, a sixth temperature sensor T6, a seventh temperature sensor T7, an eighth temperature sensor T8, a ninth temperature sensor T9, a tenth temperature sensor T10, electric switching valves (F1A valve F1A, F1B valve F1B, F2A valve F2A, and F2B valve F2B), a plate heat exchanger, a first water pump, a second water pump, and an industrial control computer for data acquisition, calculation, and control.

[0041] The area inside frame C is a water tank used for energy storage.

[0042] This invention provides a control method for a central air conditioning energy storage device, applied to the aforementioned central air conditioning energy storage device. The control method includes:

[0043] Determine whether the current moment is within a peak or trough period to obtain the first judgment result.

[0044] If the first judgment result is negative, then the outlet water temperature on the water outlet side of the computer room is set to the first temperature (which can be 7 degrees Celsius in actual applications). During normal operation of the original computer room, the first valve is closed, and the first and second water pumps are not running. The original computer room system operates according to its original design. As the operating time increases, the load decreases, and the temperature gradually decreases. Figure 2 and Figure 3 As shown, when the unit reaches time A, in order to maintain the first temperature, the air conditioning unit begins to unload. When the unit reaches time B, the load rate is at the first load rate threshold (which can be 60% in practical applications). If no measures are taken, the unit will continue to unload until it reaches the minimum load rate limit and shuts down. Therefore, if the measured outlet water temperature on the machine room outlet side (measured at T1) is equal to the first temperature and the machine room load rate is equal to the first load rate threshold... Figure 2 If the online energy storage entry point C is reached, the online energy storage mode is entered. If the difference between the water temperature at the first opening of the water tank (measured at T8) and the measured outlet water temperature on the machine room outlet side (measured at T1) is equal to the first temperature difference threshold (determined based on the difference between the primary side inlet water temperature and the secondary side outlet water temperature of the plate heat exchanger, which can be 1 degree in practical applications), and the machine room load rate is less than the first load rate threshold, then the online energy release mode is entered. The online energy storage mode is as follows: open valves F1A and F1B. 1B, close valves F2A and F2B, and execute the pump energy storage mode, then update the current time to enter the next time. The online energy release mode is as follows: shut down the machine room, the original air conditioning system (other modules besides the unit) continues to run, open valves F2A and F2B, then close valves F1A and F1B, and execute the pump energy release mode, then update the current time to enter the next time. When executing the online energy release mode (shutting down the main unit), the online energy storage mode stops. The conditions for stopping energy release are: the water tank temperature reaches a certain value (according to the computer based on meteorological conditions or a set value), and the main unit is turned on. When the load decreases and the unit begins to unload, reaching the energy storage condition, online energy storage begins.

[0045] If the first judgment result is yes, then if the water temperature at the second opening of the water tank (measured by T10) is equal to the water tank temperature setting threshold and the air conditioner is on, then peak-valley cooling mode is implemented; if the water temperature at the second opening of the water tank is greater than the water tank temperature setting threshold, then the outlet water temperature on the server room outlet side is set to the second temperature (which can be 4 degrees in practical applications), and peak-valley energy storage mode is implemented until the difference between the water temperature at the first opening of the water tank and the measured outlet water temperature on the server room outlet side is equal to the first temperature difference threshold, and the server room load rate is equal to... If the first load rate threshold is reached, the server room is shut down; if the second temperature is lower than the first temperature; the peak-valley energy storage mode is as follows: if the air conditioner is on, the first valve is opened to reduce pipeline resistance, further saving energy, and the pump energy storage mode is executed; if the air conditioner is off, the first valve is closed and the pump energy storage mode is executed, and then the current time is updated to enter the next time; the peak-valley cooling mode is as follows: the pump energy release mode is executed until the water temperature at the second opening of the water tank is equal to the water tank temperature set threshold, then the first and second water pumps are shut down, and then the current time is updated to enter the next time.

[0046] The pump energy storage mode is as follows:

[0047] The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and a preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the user's inlet side, the inlet water temperature on the primary side of the plate heat exchanger, and a preset second-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the primary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and a preset third-level PID trend principle. The operating conditions are either cooling or heating conditions.

[0048] The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-stage PID trend principle; then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the primary side of the plate heat exchanger, and the preset five-stage PID trend principle.

[0049] The pump energy release mode is as follows:

[0050] The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-level PID trend principle. Then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the secondary side of the plate heat exchanger, and the preset six-level PID trend principle.

[0051] The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and the preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the secondary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and the preset seventh-level PID trend principle.

[0052] In practical applications, the first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and the preset first-level PID trend principle, specifically including:

[0053] Obtain the primary side inlet pressure P1' (measured by P1) and the primary side outlet pressure P2' (measured by P2) of the plate heat exchanger.

[0054] The pressure difference on the primary side of the plate heat exchanger is obtained by calculating the difference between the pressure at the inlet of the primary side and the pressure at the outlet of the primary side.

[0055] With the pressure difference on the primary side of the plate heat exchanger equal to a preset pressure difference threshold (20 kPa, determined according to the actual plate heat exchanger model) as the target, the first frequency value a is obtained according to the preset first-level PID trend principle.

[0056] The first water pump is controlled according to the first frequency value.

[0057] In practical applications, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the user's inlet side, the primary inlet water temperature of the plate heat exchanger, and a preset secondary PID trend principle. Specifically, this includes:

[0058] Obtain the user's inlet water temperature T5' (measured at T5), the plate heat exchanger primary inlet water temperature T2' (measured at T2), and the server room load rate.

[0059] Based on the current operating conditions, the difference between the inlet water temperature on the user's inlet side and the inlet water temperature on the primary side of the plate heat exchanger is calculated to obtain the first target value ΔT1.

[0060] A first proportional threshold is obtained based on the first target value and the data center load rate.

[0061] With the second target value ΔT2 equal to the first proportional threshold as the objective, the second frequency value b is obtained according to the preset two-level PID trend principle.

[0062] The first water pump is controlled according to the second frequency value.

[0063] In practical applications, the first water pump is controlled based on the current operating conditions, the primary side inlet water temperature of the plate heat exchanger, the primary side outlet water temperature of the plate heat exchanger, and a preset three-level PID trend principle. Specifically, this includes:

[0064] Obtain the primary side inlet water temperature T2' (measured by T2) and the primary side outlet water temperature T3' (measured by T3) of the plate heat exchanger.

[0065] Based on the current operating conditions, the difference between the primary side inlet water temperature and the primary side outlet water temperature of the plate heat exchanger is calculated to obtain the third target value ΔT3.

[0066] With the goal of the third target value being equal to the second preset difference threshold, the third frequency value c is obtained based on the preset three-level PID trend principle.

[0067] The first water pump is controlled according to the third frequency value.

[0068] In practical applications, the second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-level PID trend principle, specifically including:

[0069] Obtain the secondary side inlet pressure P3' (measured by P3) and the secondary side outlet pressure P4' (measured by P4) of the plate heat exchanger.

[0070] The pressure difference on the secondary side of the plate heat exchanger is obtained by calculating the difference between the pressure at the secondary inlet and the pressure at the secondary outlet of the plate heat exchanger.

[0071] With the pressure difference on the secondary side of the plate heat exchanger equal to a preset pressure difference threshold as the target, the fourth frequency value d is obtained according to the preset four-level PID trend principle.

[0072] The second water pump is controlled according to the fourth frequency value.

[0073] In practical applications, the second water pump is controlled based on the current operating conditions, the secondary side outlet water temperature of the plate heat exchanger, the primary side inlet water temperature of the plate heat exchanger, and a preset five-stage PID trend principle. Specifically, this includes:

[0074] Obtain the secondary side outlet water temperature T7' (measured at T7) and the primary side inlet water temperature T2' (measured at T2) of the plate heat exchanger.

[0075] Based on the current operating conditions, the difference between the secondary side outlet water temperature and the primary side inlet water temperature of the plate heat exchanger is calculated to obtain the fourth target value ΔT4.

[0076] With the fourth target value equal to the first preset difference threshold as the objective, the fifth frequency value e is obtained according to the preset five-level PID trend principle.

[0077] The second water pump is controlled according to the fifth frequency value.

[0078] In practical applications, the second water pump is controlled based on the current operating conditions, the secondary side outlet water temperature of the plate heat exchanger, the secondary side inlet water temperature of the plate heat exchanger, and a preset six-level PID trend principle. Specifically, this includes:

[0079] Obtain the secondary side outlet water temperature T7' (measured at T7) and the secondary side inlet water temperature T6' (measured at T6) of the plate heat exchanger.

[0080] Based on the current operating conditions, the difference between the secondary side outlet water temperature and the secondary side inlet water temperature of the plate heat exchanger is calculated to obtain the fifth target value ΔT5.

[0081] With the fifth target value equal to the second preset difference threshold as the objective, the sixth frequency value f is obtained according to the preset six-level PID trend principle.

[0082] The second water pump is controlled according to the sixth frequency value f.

[0083] In practical applications, the first water pump is controlled based on the current operating conditions, the secondary side inlet water temperature of the plate heat exchanger, the primary side outlet water temperature of the plate heat exchanger, and a preset seven-level PID trend principle. Specifically, this includes:

[0084] Obtain the secondary side inlet water temperature T6' (measured at T6) and the primary side outlet water temperature T3' (measured at T3) of the plate heat exchanger.

[0085] Based on the current operating conditions, the difference between the secondary side inlet water temperature and the primary side outlet water temperature of the plate heat exchanger is calculated to obtain the sixth target value ΔT6.

[0086] With the sixth target value equal to the first preset difference threshold as the objective, the seventh frequency value G is obtained according to the preset seven-level PID trend principle.

[0087] The second water pump is controlled according to the seventh frequency value.

[0088] In practical applications, pump energy storage modes specifically include:

[0089] The operating logic of the first water pump (the first water pump transfers "heat" from the main pipe to the primary side of the plate heat exchanger):

[0090] Step 1: After the first water pump starts, calculate the difference between pressure sensors P1 and P2 (P1'-P2') to make the pressure difference between pressure sensors P1 and P2 20 kPa. Obtain the first frequency value a through the preset first-level PID trend principle. Adjust the first water pump according to a (the initial value that can form an effective water flow) to form a basic water flow. The operating range of the frequency in the preset first-level PID trend principle is 0 to 100%.

[0091] Step 2: Calculate ΔT1 (ΔT1 = T5' - T2' in cooling mode, ΔT1 = T2' - T5' in heating mode), then calculate ΔT1' based on ΔT1' = ΔT1 / unit (machine room) load rate % , such as Figure 4 The control target value of the preset two-level PID trend principle is ΔT2. Let ΔT2 = ΔT1' / unit (machine room) load rate %, calculate the second frequency value b, b ranges from a to c%, and b controls the variable frequency operation of the first water pump. When the unit load rate decreases (indicating a decrease in load), ΔT2 is automatically adjusted. In the first adjustment, ΔT1' is preset, and the initial ΔT1' = 1 degree (set value, to ensure that the user side is not disturbed).

[0092] Step 3: To improve the efficiency of the plate heat exchanger and water pump, calculate ΔT3 (ΔT3 = T3' - T2' in cooling mode, and ΔT3 = T2' - T3' in heating mode). Figure 5 As shown, in the preset three-level PID trend principle, the control target value is ΔT3. Let ΔT3 = 3 degrees (set value, determined according to the actual heat exchanger model). Calculate the third frequency value c, where c ranges from a to 100%. c controls the variable frequency operation of the first water pump. The overall operating logic is as follows: Figure 6 As shown.

[0093] The second water pump's operating logic (the second water pump transfers the "heat" from the primary side of the plate heat exchanger to the energy storage tank in block diagram C):

[0094] Step 1: After the second water pump starts, based on the difference between pressure sensors P3 and P4 (P3'-P4'), the second water pump is controlled by the preset four-level PID trend principle, so that the pressure difference between pressure sensors P3 and P4 on the "secondary pressure side" of the plate heat exchanger is 20 kPa (assumed value, adjustable), forming the basic water flow. The computer's internal "four-level" PID operation range is 0 to 100%. Let the actual value of the variable frequency second water pump at this time be the fourth frequency value d.

[0095] Step 2: Calculate ΔT4 (ΔT4 = T7' - T2' in cooling mode, ΔT4 = T2' - T7' in heating mode). Figure 7As shown, the target value of the preset five-level PID trend principle is ΔT4. Let ΔT4 = 1 degree, calculate the fifth frequency value e, where e ranges from d to 100%. The second water pump is controlled by the value of e. The overall operating logic of the preset five-level PID trend principle is as follows: Figure 8 As shown.

[0096] In practical applications, the pump energy release mode is as follows:

[0097] Second water pump operation logic:

[0098] Step 1: After the second water pump starts, based on the difference between pressure sensors P3 and P4 (P3'-P4'), the second water pump is controlled by the preset four-level PID trend principle, so that the pressure difference between pressure sensors P3 and P4 on the "secondary pressure side" of the plate heat exchanger is 20 kPa (assumed value, adjustable), forming the basic water flow. The computer's internal "four-level" PID operation range is 0 to 100%. Let the actual value of the variable frequency second water pump at this time be the fourth frequency value d.

[0099] Step 2: Calculate ΔT5 (ΔT5 = T7' - T6' in cooling mode, ΔT5 = T6' - T7' in heating mode). The preset control target value based on the six-level PID trend principle is ΔT5. Let ΔT5 = 3 degrees, calculate the sixth frequency value f, where f ranges from d to 100%. Control the second water pump based on f. The overall operating logic is as follows: Figure 9 As shown.

[0100] First water pump operating logic:

[0101] Step 1: After the first water pump starts, based on the difference between pressure sensors P1 and P2 (P1'-P2'), the first water pump is adjusted according to the preset first-level PID trend principle, so that the pressure difference between pressure sensors P1 and P2 on the "pressure primary side" of the plate heat exchanger is 20 kPa, forming a basic water flow. The operating range of the frequency in the preset first-level PID trend principle is 0 to 100%. Let the actual value of the operating frequency of the first water pump at this time be a (the initial value that can form an effective water flow).

[0102] Step 2: Calculate ΔT6 (ΔT6 = T3' - T6' in cooling mode, ΔT6 = T6' - T3' in heating mode). The preset control target value based on the seven-level PID trend principle is ΔT6 = 1 degree. Calculate the seventh frequency value G, where G ranges from a to 100%. Control the first water pump based on G. The overall operating logic is as follows: Figure 10 As shown.

[0103] This invention achieves energy storage on the basis of the original central air conditioning system through simple "multi-level coupling" without changing the original air conditioning management. The system is set with online energy storage mode and peak-valley energy storage mode. The online energy storage mode is used to solve the problem of frequent unit start-up and avoid inefficient operation of the unit at low load. The peak-valley energy storage mode is mainly used for peak and off-peak electricity charges at night, and the system stores energy.

[0104] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0105] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A central air conditioning energy storage device, characterized in that, include: Original computer room water inlet and outlet pipes, energy storage modules and water tank; The original water inlet and outlet pipelines of the computer room include: user return water side, user inlet water side, computer room return water side, computer room outlet water side and first valve; the energy storage module includes: plate heat exchanger, first water pump, second water pump, F1A valve, F1B valve, F2A valve, F2B valve and industrial control computer; The first valve is installed between the user's water inlet side and the user's water return side; the machine room water outlet side and the user's water inlet side are connected by a first pipe; the first pipe is connected to the primary side inlet of the plate heat exchanger through a primary side water inlet pipe; the first pipe is connected to the primary side outlet of the plate heat exchanger through a primary side water outlet pipe; and the first water pump is installed on the primary side water inlet pipe. The secondary side inlet of the plate heat exchanger is connected to the first opening of the water tank via a secondary side inlet pipe, and the secondary side outlet of the plate heat exchanger is connected to the secondary side inlet pipe via a secondary side outlet pipe; valve F2A is installed on the secondary side outlet pipe; the second opening of the water tank is connected to the secondary side inlet pipe via an outlet pipe, and valve F2B is installed on the outlet pipe; the outlet pipe is connected to the secondary side outlet pipe via a bypass pipe, and valve F1A is installed on the bypass pipe; valve F2A is located between the first and second interfaces, valve F1B is located between the first and third interfaces, and the second water pump is located between the third interface and the secondary side inlet of the plate heat exchanger; the first interface is the connection point between the secondary side inlet pipe and the secondary side outlet pipe; the second interface is the connection point between the bypass pipe and the secondary side outlet pipe; and the third interface is the connection point between the outlet pipe and the secondary side inlet pipe. The industrial control computer is connected to the first water pump, the second water pump, the F1A valve, the F1B valve, the F2A valve, the F2B valve, and the first valve, respectively. The industrial control computer is used to control the first water pump, the second water pump, the F1A valve, the F1B valve, the F2A valve, the F2B valve, and the first valve based on the pressure difference on the primary side and the pressure difference on the secondary side of the plate heat exchanger, the primary side inlet water temperature, the secondary side inlet water temperature, the primary side outlet water temperature, the secondary side outlet water temperature, the water temperature at the first opening of the water tank, the water temperature at the second opening of the water tank, the outlet water temperature on the machine room outlet side, and the inlet water temperature on the user inlet side. Specifically, this includes: determining whether the current time is during a peak or valley period and obtaining a first determination result. If the first judgment result is negative, the outlet water temperature on the machine room outlet side is set as the first temperature. If the measured outlet water temperature on the machine room outlet side is equal to the first temperature and the machine room load rate is equal to the first load rate threshold, then the online energy storage mode is entered. If the difference between the water temperature at the first opening of the water tank and the measured outlet water temperature on the machine room outlet side is equal to the first temperature difference threshold, and the machine room load rate is less than the first load rate threshold, then the online energy release mode is entered. The online energy storage mode is as follows: open valves F1A and F1B, close valves F2A and F2B, and execute pump energy storage mode, then update the current time and enter the next time. The online energy release mode is as follows: close the machine room, open valves F2A and F2B, then close valves F1A and F1B, and execute pump energy release mode, then update the current time and enter the next time. If the first judgment result is yes, then if the water temperature at the second opening of the water tank is equal to the water tank temperature setting threshold and the air conditioner is on, then the peak-valley cooling mode is implemented; if the water temperature at the second opening of the water tank is greater than the water tank temperature setting threshold, then the outlet water temperature on the machine room outlet side is set to the second temperature, and the peak-valley energy storage mode is entered until the difference between the water temperature at the first opening of the water tank and the measured outlet water temperature on the machine room outlet side is equal to the first temperature difference threshold, and the machine room load rate is equal to the first load rate threshold, then the machine room is shut down; the second temperature is less than the first temperature; the peak-valley energy storage mode is as follows: if the air conditioner is on, then the first valve is opened and the pump energy storage mode is executed; if the air conditioner is off, then the first valve is closed and the pump energy storage mode is executed, and then the current time is updated to enter the next time; the peak-valley cooling mode is as follows: the pump energy release mode is executed until the water temperature at the second opening of the water tank is equal to the water tank temperature setting threshold, then the first water pump and the second water pump are shut down, and then the current time is updated to enter the next time. The pump energy storage mode is as follows: The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and a preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the user's inlet side, the inlet water temperature on the primary side of the plate heat exchanger, and a preset second-level PID trend principle. Finally, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the primary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and a preset third-level PID trend principle. The operating conditions are either cooling or heating. The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-stage PID trend principle; then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the primary side of the plate heat exchanger, and the preset five-stage PID trend principle. The pump energy release mode is as follows: The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-level PID trend principle. Then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the secondary side of the plate heat exchanger, and the preset six-level PID trend principle. The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and the preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the secondary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and the preset seventh-level PID trend principle.

2. The central air conditioning energy storage device according to claim 1, characterized in that, Also includes: First pressure sensor, second pressure sensor, third pressure sensor, fourth pressure sensor, first temperature sensor, second temperature sensor, third temperature sensor, fourth temperature sensor, fifth temperature sensor, sixth temperature sensor, seventh temperature sensor, eighth temperature sensor, ninth temperature sensor and tenth temperature sensor; The first pressure sensor is disposed between the first water pump and the primary side inlet of the plate heat exchanger; the second temperature sensor is disposed between the first pressure sensor and the primary side inlet of the plate heat exchanger; the second pressure sensor is disposed between the primary side outlet of the plate heat exchanger and the fourth interface; the third temperature sensor is disposed between the second pressure sensor and the primary side outlet of the plate heat exchanger; the third pressure sensor is disposed between the second water pump and the secondary side inlet of the plate heat exchanger; the sixth temperature sensor is disposed between the second water pump and the third pressure sensor; the fourth pressure sensor is disposed between the second interface and the secondary side outlet of the plate heat exchanger; and the seventh temperature sensor... The sensor is located between the fourth pressure sensor and the second interface; the first temperature sensor is located between the water outlet side of the machine room and the fifth interface; the fourth temperature sensor is located between the fourth interface and the fifth interface; the fifth temperature sensor is located between the fourth interface and the user's water inlet side; the eighth temperature sensor is located between the first interface and the first opening of the water tank; the ninth temperature sensor is located between the second opening of the water tank and the F2B valve; the tenth temperature sensor is located at the second opening of the water tank; the fourth interface is the connection point between the primary side water outlet pipe and the first pipe; the fifth interface is the connection point between the primary side water inlet pipe and the first pipe.

3. A control method for a central air conditioning energy storage device, characterized in that, The control method, applied to the central air conditioning energy storage device as described in any one of claims 1-2, comprises: Determine whether the current moment is within a peak / valley period to obtain the first judgment result; If the first judgment result is negative, the outlet water temperature on the machine room outlet side is set as the first temperature. If the measured outlet water temperature on the machine room outlet side is equal to the first temperature and the machine room load rate is equal to the first load rate threshold, then the online energy storage mode is entered. If the difference between the water temperature at the first opening of the water tank and the measured outlet water temperature on the machine room outlet side is equal to the first temperature difference threshold, and the machine room load rate is less than the first load rate threshold, then the online energy release mode is entered. The online energy storage mode is as follows: open valves F1A and F1B, close valves F2A and F2B, and execute pump energy storage mode, then update the current time and enter the next time. The online energy release mode is as follows: close the machine room, open valves F2A and F2B, then close valves F1A and F1B, and execute pump energy release mode, then update the current time and enter the next time. If the first judgment result is yes, then if the water temperature at the second opening of the water tank is equal to the water tank temperature setting threshold and the air conditioner is on, then the peak-valley cooling mode is implemented; if the water temperature at the second opening of the water tank is greater than the water tank temperature setting threshold, then the outlet water temperature on the machine room outlet side is set to the second temperature, and the peak-valley energy storage mode is entered until the difference between the water temperature at the first opening of the water tank and the measured outlet water temperature on the machine room outlet side is equal to the first temperature difference threshold, and the machine room load rate is equal to the first load rate threshold, then the machine room is shut down; the second temperature is less than the first temperature; the peak-valley energy storage mode is as follows: if the air conditioner is on, then the first valve is opened and the pump energy storage mode is executed; if the air conditioner is off, then the first valve is closed and the pump energy storage mode is executed, and then the current time is updated to enter the next time; the peak-valley cooling mode is as follows: the pump energy release mode is executed until the water temperature at the second opening of the water tank is equal to the water tank temperature setting threshold, then the first water pump and the second water pump are shut down, and then the current time is updated to enter the next time. The pump energy storage mode is as follows: The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and a preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the user's inlet side, the inlet water temperature on the primary side of the plate heat exchanger, and a preset second-level PID trend principle. Finally, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the primary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and a preset third-level PID trend principle. The operating conditions are either cooling or heating. The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-stage PID trend principle; then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the primary side of the plate heat exchanger, and the preset five-stage PID trend principle. The pump energy release mode is as follows: The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-level PID trend principle. Then, the second water pump is controlled based on the current operating conditions, the outlet water temperature on the secondary side of the plate heat exchanger, the inlet water temperature on the secondary side of the plate heat exchanger, and the preset six-level PID trend principle. The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and the preset first-level PID trend principle. Then, the first water pump is controlled based on the current operating conditions, the inlet water temperature on the secondary side of the plate heat exchanger, the outlet water temperature on the primary side of the plate heat exchanger, and the preset seventh-level PID trend principle.

4. The control method for the central air conditioning energy storage device according to claim 3, characterized in that, The first water pump is controlled based on the pressure difference on the primary side of the plate heat exchanger and a preset first-level PID trend principle, specifically including: Obtain the primary side inlet pressure and the primary side outlet pressure of the plate heat exchanger; The pressure difference on the primary side of the plate heat exchanger is obtained by calculating the difference between the pressure at the inlet of the primary side and the pressure at the outlet of the primary side. With the pressure difference on the primary side of the plate heat exchanger equal to a preset pressure difference threshold as the target, the first frequency value is obtained according to the preset first-level PID trend principle; The first water pump is controlled according to the first frequency value.

5. The control method for the central air conditioning energy storage device according to claim 3, characterized in that, The first water pump is controlled based on the current operating conditions, the inlet water temperature on the user's inlet side, the primary inlet water temperature of the plate heat exchanger, and a preset secondary PID trend principle. Specifically, this includes: Obtain the inlet water temperature on the user's inlet side, the primary inlet water temperature of the plate heat exchanger, and the load rate of the computer room; Based on the current operating conditions, the difference between the inlet water temperature on the user's inlet side and the inlet water temperature on the primary side of the plate heat exchanger is calculated to obtain the first target value. A first proportional threshold is obtained based on the first target value and the data center load rate; With the second target value equal to the first proportional threshold as the objective, the second frequency value is obtained according to the preset two-level PID trend principle; The first water pump is controlled according to the second frequency value.

6. The control method for the central air conditioning energy storage device according to claim 3, characterized in that, The first water pump is controlled based on the current operating conditions, the primary side inlet water temperature of the plate heat exchanger, the primary side outlet water temperature of the plate heat exchanger, and a preset three-level PID trend principle. Specifically, this includes: Obtain the primary side inlet water temperature and the primary side outlet water temperature of the plate heat exchanger; Based on the current operating conditions, the difference between the primary side inlet water temperature and the primary side outlet water temperature of the plate heat exchanger is calculated to obtain the third target value. With the goal of the third target value being equal to the second preset difference threshold, the third frequency value is obtained based on the preset three-level PID trend principle; The first water pump is controlled according to the third frequency value.

7. The control method for the central air conditioning energy storage device according to claim 3, characterized in that, The second water pump is controlled based on the pressure difference on the secondary side of the plate heat exchanger and the preset four-level PID trend principle, specifically including: Obtain the secondary side inlet pressure and the secondary side outlet pressure of the plate heat exchanger. The pressure difference on the secondary side of the plate heat exchanger is obtained by calculating the difference between the pressure at the secondary inlet and the pressure at the secondary outlet of the plate heat exchanger. With the pressure difference on the secondary side of the plate heat exchanger equal to a preset pressure difference threshold as the target, the fourth frequency value is obtained according to the preset four-level PID trend principle; The second water pump is controlled according to the fourth frequency value.

8. The control method for the central air conditioning energy storage device according to claim 3, characterized in that, The second water pump is controlled based on the current operating conditions, the secondary side outlet water temperature of the plate heat exchanger, the primary side inlet water temperature of the plate heat exchanger, and a preset five-stage PID trend principle. Specifically, this includes: Obtain the secondary side outlet water temperature and the primary side inlet water temperature of the plate heat exchanger. Based on the current operating conditions, the difference between the secondary side outlet water temperature and the primary side inlet water temperature of the plate heat exchanger is calculated to obtain the fourth target value. With the fourth target value equal to the first preset difference threshold as the objective, the fifth frequency value is obtained according to the preset five-level PID trend principle; The second water pump is controlled according to the fifth frequency value.

9. The control method for the central air conditioning energy storage device according to claim 3, characterized in that, The second water pump is controlled based on the current operating conditions, the secondary side outlet water temperature of the plate heat exchanger, the secondary side inlet water temperature of the plate heat exchanger, and the preset six-level PID trend principle. Specifically, this includes: Obtain the secondary side outlet water temperature and the secondary side inlet water temperature of the plate heat exchanger. Based on the current operating conditions, the difference between the secondary side outlet water temperature and the secondary side inlet water temperature of the plate heat exchanger is calculated to obtain the fifth target value. With the fifth target value equal to the second preset difference threshold as the objective, the sixth frequency value is obtained according to the preset six-level PID trend principle; The second water pump is controlled according to the sixth frequency value.

10. The control method for the central air conditioning energy storage device according to claim 3, characterized in that, The first water pump is controlled based on the current operating conditions, the secondary inlet water temperature of the plate heat exchanger, the primary outlet water temperature of the plate heat exchanger, and a preset seven-level PID trend principle. Specifically, this includes: Obtain the secondary side inlet water temperature and the primary side outlet water temperature of the plate heat exchanger; Based on the current operating conditions, the difference between the secondary side inlet water temperature and the primary side outlet water temperature of the plate heat exchanger is calculated to obtain the sixth target value. With the sixth target value equal to the first preset difference threshold as the objective, the seventh frequency value is obtained according to the preset seven-level PID trend principle; The first water pump is controlled according to the seventh frequency value.

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