A decoupled high-efficiency central air-conditioning chilled water control system and method

Abstract

The invention discloses a decoupled high-efficiency central air-conditioning chilled water control system and method. The decoupled high-efficiency central air-conditioning chilled water control system comprises a modular chilled water pump energy efficiency control cabinet composed of a host and a plurality of slaves. The cabinets of the host and each slave are provided with a power system unit, a speed regulation system unit and a control system unit. The control system units of the host and the slave are connected via a communication interaction network. The signal ends of valves A and B and each signal probe group are uniformly connected to the control system unit of the host. The signal ends of each water pump in the chilled water pump group are respectively connected to the control system unit of the host and the slave. Each host or slave is used to drive a water pump. The host is used to obtain and calculate the operating condition information of the chilled water system and allocate and dispatch the slaves. When the communication network is normal, the host is responsible for allocating and dispatching the operation. When the communication network is abnormal, the slave maintains the current state operation.

Description

Technical Field

[0001] The invention relates to a decoupled high-efficiency central air-conditioning chilled water control system and method, belonging to the technical field of water-cooled central air-conditioning energy-saving control. Background Art

[0002] In the field of energy-saving control systems for large water-cooled central air conditioners, almost all energy-saving controls for central air conditioner systems use system-integrated BA system control (Building Automation System). This traditional central air conditioner BA system control is Figure 1 As shown, the advantages of this form of control are:

[0003] 1. DDC controller can be selected, TCP / IP protocol is adopted to realize Ethernet communication network with high communication rate;

[0004] 2. System group control, the control loop is relatively centralized, only one application is needed to meet the operation of the entire system;

[0005] 3. The control scheme can be downloaded on-site by computer, which is flexible to use;

[0006] 4. The DDC has preset control schemes for easy installation and debugging. Multiple data communication methods are suitable for various controlled devices and system integration.

[0007] Due to the above advantages, BA system control is widely used in various building construction, industrial control, intelligent instrumentation and other fields, but this BA system control still has the following disadvantages:

[0008] 1. If the signal probe fails, the entire system will be out of control;

[0009] 2. If the DDC controller fails, the entire system will not be able to operate and the security level will be low;

[0010] 3. Professional personnel are required to perform on-site programming and debugging, and the implementation cycle of the system is relatively long. Summary of the invention

[0011] The purpose of the present invention is to provide a decoupled high-efficiency central air-conditioning chilled water control system and method, so as to solve the technical problem that the whole system cannot operate normally when the signal probe fails or the DDC controller is abnormal in the prior art central air-conditioning control system.

[0012] The decoupled high-efficiency central air-conditioning chilled water control system of the present invention adopts the following technical scheme: a decoupled high-efficiency central air-conditioning chilled water control system, which includes a terminal air-conditioning system group, a main unit group, and a chilled water pump group. The terminal total return water pipe on the water collector of the terminal air-conditioning system group is connected to the total inlet of the chilled water pump group, the total outlet water pipe of the chilled water pump group is connected to the total inlet of the main unit group, and the total outlet water pipe of the main unit group is connected to the inlet of the water distributor of the terminal air-conditioning system group. An A-end flow compensation pipe is arranged between the terminal total return water pipe and the main unit total outlet water pipe. The diameter of the A-end flow compensation pipe is smaller than the diameter of the terminal total return water pipe or the main unit total outlet water pipe. A B-end flow compensation pipe is arranged between the total outlet water pipe of the chilled water pump and the main unit total outlet water pipe. The diameter of the B-end flow compensation pipe is smaller than the diameter of the total outlet water pipe of the chilled water pump or the main unit total outlet water pipe. A valve and B valve are respectively arranged on the A-end flow compensation pipe and the B-end flow compensation pipe, and both the A valve and the B valve are electric valves. The decoupled high-efficiency central air-conditioning chilled water control system also includes a signal probe group, a modular chilled water pump energy efficiency control cabinet group and an energy efficiency management and control platform.

[0013] The signal probe group is divided into three groups and has a designated installation position: the first group is the pressure sensor and temperature sensor installed on the main outlet pipe of the chilled water pump; the second group is the pressure sensor and temperature sensor installed on the main outlet pipe of the main unit; the third group is the pressure sensor and temperature sensor installed on the terminal main return pipe; one end of the flow compensation pipe at the A end is located after the first group of signal probes and the other end is located before the second group of signal probes, and one end of the flow compensation pipe at the B end is located before the second group of signal probes and the other end is located after the third group of signal probes;

[0014] The modular chilled water pump energy efficiency control cabinet group includes a host and more than one slave. The cabinets of the host and each slave are equipped with a power system unit, a speed control system unit and a control system unit. The control system unit sends the calculation results to the speed control system unit. The control system units of the host and the slave are connected through a communication interaction network. The signal ends of valves A and B and each signal probe group are uniformly connected to the control system unit of the host. The signal ends of each water pump in the chilled water pump group are respectively connected to the control system units of the host and the slave. Each host or slave is used to drive a water pump. The host is used to obtain and calculate the operating condition information of the chilled water system and allocate and schedule the slave. When the communication network is normal, the host is responsible for allocating and scheduling the operation. When the communication network is abnormal, the slave maintains the current state of operation; the energy efficiency management and control platform is connected to the host of the modular chilled water pump energy efficiency control cabinet group for data exchange.

[0015] The host and each slave are designed with integrated strong and weak electricity, and there are up to 7 slaves.

[0016] The host and slave use RS485 interface to realize hand-in-hand communication interactive network connection.

[0017] The decoupled high-efficiency central air-conditioning chilled water control method of the present invention adopts the following technical scheme: a decoupled high-efficiency central air-conditioning chilled water control method, connecting each signal probe group and the signal ends of valve A and valve B to the host of a modular chilled water pump energy efficiency control cabinet group, performing energy efficiency control calculation, and performing flow compensation on the chilled water circuit by adjusting valve A and valve B, each signal probe group is used to collect the temperature and pressure values ​​at the corresponding pipeline, the pressure and temperature measured by the pressure sensor and temperature sensor installed on the total outlet pipe of the chilled water pump are P0 and T1 respectively, the pressure and temperature measured by the pressure sensor and temperature sensor installed on the total outlet pipe of the host group are P1 and T0 respectively, and the pressure and temperature measured by the pressure sensor and temperature sensor installed on the terminal total return pipe are P2 and T2 respectively;

[0018] 1. The flow compensation logic and algorithm are as follows:

[0019] Current total traffic ΔPPV 总 = Current host traffic ΔPPV 主机端 +Current terminal flow ΔPPV 末端

[0020] Among them: Current host traffic ΔPPV 主机端 =P0-P1, current terminal flow ΔPPV 末端 =P1-P2

[0021] Total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 +Terminal flow demand ΔPSV 末端

[0022] Host-side traffic demand ΔPSV 主机端 and terminal flow demand ΔPSV 末端 They are all artificial settings;

[0023] 1) If ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 , then valve A or valve B will not be regulated and maintain the current state;

[0024] 2) If ΔPPV 主机端 <ΔPSV 主机端 , ΔPPV 末端 >ΔPSV 末端 , then valve A opens and the opening gradually increases until ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 When , valve A stops increasing and maintains the current state;

[0025] 3) If ΔPPV 主机端 >ΔPSV 主机端 , ΔPPV 末端 <ΔPSV 末端 , then valve B opens and the opening gradually increases until ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 When , valve B stops increasing and maintains the current state;

[0026] 2. The energy efficiency control algorithm is as follows:

[0027] 1) Basic algorithm:

[0028] A. When the host is the target: Current total traffic ΔPPV 总 = Current host traffic ΔPPV 主机端 , total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 ;

[0029] B. When the end is the target: Current total flow ΔPPV 总 = Current terminal flow ΔPPV 末端 , total flow demand ΔPSV 总 = Terminal flow demand ΔPSV 末端 ;

[0030] C. When bilateral flow is the target: Current total flow ΔPPV 总 = Current host traffic ΔPPV 主机端 +Current terminal flow ΔPPV 末端 , total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 +Terminal flow demand ΔPSV 末端 ;

[0031] 2) Load temperature difference flow correction algorithm:

[0032] A. Host-side compensation upper and lower limits calculation:

[0033] a) Host-side ΔT correction ΔP compensation upper limit = total flow demand ΔPSV 总 × Host-side ΔT correction ΔP compensation upper limit ratio;

[0034] b) Host-side ΔT correction ΔP compensation lower limit = total flow demand ΔPSV 总 × Host-side ΔT correction ΔP compensation lower limit ratio;

[0035] B. Calculation of upper and lower limits of terminal compensation:

[0036] a) Terminal ΔT correction ΔP compensation upper limit = total flow demand ΔPSV 总 × The upper limit ratio of ΔT correction ΔP compensation at the end;

[0037] b) Terminal ΔT correction ΔP compensation lower limit = total flow demand ΔPSV 总 × Terminal ΔT correction ΔP compensation lower limit ratio;

[0038] C. If the A or B valve compensation is turned on, the calculation starts, otherwise the compensation value is 0:

[0039] Among them, the host end sampling temperature difference = T1-T0, the terminal end sampling temperature difference = T2-T1, and the standard working condition temperature difference between the host end and the terminal end adopts the set standard value;

[0040] a) When the host-side sampled temperature difference is less than the host-side standard operating temperature difference, the host-side ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, it is reduced by the set fixed value, and the cycle repeats. When the host-side ΔT correction ΔP compensation value is less than or equal to the host-side ΔT correction ΔP compensation lower limit value, the reduction of the set fixed value is stopped;

[0041] b) When the host-side sampled temperature difference is greater than the host-side standard operating temperature difference, the host-side ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, the set fixed value is added, and the cycle repeats. When the host-side ΔT correction ΔP compensation value is greater than or equal to the host-side ΔT correction ΔP compensation upper limit value, the set fixed value is stopped;

[0042] c) When the terminal sampling temperature difference is less than the terminal standard operating temperature difference, the terminal ΔT repair ΔP compensation value starts from 0, and when the custom pulse time is reached, it is reduced by the set fixed value, and the cycle repeats. When the terminal ΔT repair ΔP compensation value is less than or equal to the terminal ΔT repair ΔP compensation lower limit, the fixed value is stopped from being reduced;

[0043] d) When the terminal sampling temperature difference is greater than the terminal standard operating temperature difference, the terminal ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, the set fixed value is added, and the cycle is repeated. When the terminal ΔT correction ΔP compensation value is greater than or equal to the terminal ΔT correction ΔP compensation upper limit value, the set fixed value is stopped;

[0044] A valve or B valve compensation opening operation result: the actual flow rate of the pump is always measured by the current total flow ΔPPV 总 ΔPSV vs. total flow demand 总 By comparing the opening of valve A or valve B, the current total flow rate ΔPPV can be guaranteed. 总 = Total flow demand ΔPSV 总 , if the current total flow ΔPPV 总 = Total flow demand ΔPSV 总 , the water pump maintains the current work unchanged.

[0045] The energy efficiency control algorithm also includes a temperature trend prediction and compensation algorithm, as follows:

[0046] When the T2 sampling temperature is less than or equal to the starting temperature, the standard operating temperature difference increases by 0.1°C every minute;

[0047] When the T2 sampling temperature is greater than or equal to the end temperature, the standard operating temperature difference decreases by 0.1°C every minute;

[0048] The starting temperature and ending temperature are both set values.

[0049] The standard operating temperature difference between the host end and the terminal end is 5°C, the starting temperature adopts the standard operating temperature of 7°C, and the ending temperature is 12°C.

[0050] The custom pulse time is 60-120s.

[0051] The set fixed value is 1Kpa.

[0052] The range of the opening of valve A or valve B is 0~100%, and the amount of each change is 0.5% of the maximum opening.

[0053] The sampling cycle of temperature and pressure is 1s / time.

[0054] The beneficial effects of the present invention are as follows: the modular chilled water pump energy efficiency control cabinet group of the present invention is divided into a host and a slave, the host is responsible for the acquisition and calculation of the operating condition information of the chilled water system, the allocation and scheduling of the slaves, and all the slaves obey the dispatching command of the host. When the communication network is normal, the host is responsible for the allocation and scheduling operation; when the host and the slave interactive network are disconnected, the slave maintains the current operating state, and is still dispatched and commanded by the host after the communication interactive network is restored. The host obeys the dispatching command of the energy efficiency management and control platform. When the energy efficiency management and control platform loses connection with the host, it does not affect the decoupled modular high-efficiency central air-conditioning chilled water control system.

[0055] The decoupled modular high-efficiency central air-conditioning chilled water control system of the present invention is suitable for a main pipe type chilled water circulation system or a one-to-one type chilled water circulation system. The present invention decouples the entire large-scale water-cooled central air-conditioning system to realize modular energy-saving control operation of the chilled water system. The process control modularization between the systems is not related to each other. When the communication network is abnormal, the modular design enables the slave machine to maintain the current state operation, realizes the modular control operation of the chilled water system, and will not affect the operation of the entire system due to a problem at one point. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is the control principle diagram of the integrated BA system of central air conditioning in the prior art;

[0057] Figure 2This is a system diagram of a decoupled high-efficiency central air-conditioning chilled water control system according to an embodiment of the present invention;

[0058] Figure 3 yes Figure 2 Schematic diagram of the master and slave.

[0059] In the figure: 1- chilled water pump group, 2- terminal main return pipe, 3- chilled water pump group main outlet pipe, 4- main unit main outlet pipe, 5- A end flow compensation pipe, 6- B end flow compensation pipe, 7- A valve, 8- B valve. DETAILED DESCRIPTION

[0060] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] like Figures 2 to 3 As shown, a decoupled high-efficiency central air-conditioning chilled water control system according to an embodiment of the present invention comprises a terminal air-conditioning system group, a main unit group, and a chilled water pump group 1. The terminal total return water pipe 2 on the water collector of the terminal air-conditioning system group is connected to the total inlet of the chilled water pump group 1, the total outlet water pipe 3 of the chilled water pump group is connected to the total inlet of the main unit group, and the total outlet water pipe 4 of the main unit group is connected to the inlet of the water distributor of the terminal air-conditioning system group. An A-end flow compensation pipe 5 is provided between the terminal total return water pipe 2 and the main unit total outlet water pipe 4. The diameter of the A-end flow compensation pipe 5 is smaller than the diameter of the terminal total return water pipe 2 or the diameter of the main unit total outlet water pipe 4. A B-end flow compensation pipe 6 is provided between the total outlet water pipe 3 of the chilled water pump and the main unit total outlet water pipe 4. The diameter of the B-end flow compensation pipe 6 is smaller than the diameter of the total outlet water pipe 3 of the chilled water pump or the diameter of the total outlet water pipe 4 of the main unit. A valve 7 and B valve 8 are provided on the A-end flow compensation pipe 5 and the B-end flow compensation pipe 5, respectively. Both the A valve 7 and the B valve 8 are electric valves.

[0062] Decoupled high-efficiency central air-conditioning chilled water control system The decoupled high-efficiency central air-conditioning chilled water control system also includes a signal probe group, a modular chilled water pump energy efficiency control cabinet group and an energy efficiency management and control platform; the signal probe group is divided into three groups and has a designated installation position: the first group is a pressure sensor and a temperature sensor installed on the total outlet pipe of the chilled water pump; the second group is a pressure sensor and a temperature sensor installed on the total outlet pipe of the main unit; the third group is a pressure sensor and a temperature sensor installed on the terminal total return pipe; one end of the A-end flow compensation pipe is located after the first group of signal probes and the other end is located before the second group of signal probes, and one end of the B-end flow compensation pipe is located before the second group of signal probes and the other end is located after the third group of signal probes;

[0063] The modular chilled water pump energy efficiency control cabinet group includes a host and more than one slave. The cabinets of the host and each slave are equipped with a power system unit, a speed control system unit and a control system unit. The control system unit sends the calculation results to the speed control system unit. The control system units of the host and the slave are connected through a communication interaction network. The signal ends of valves A and B and each signal probe group are uniformly connected to the control system unit of the host. The signal ends of each water pump in the chilled water pump group are respectively connected to the control system units of the host and the slave. Each host or slave is used to drive a water pump. The host is used to obtain and calculate the operating condition information of the chilled water system and allocate and dispatch the slaves. When the communication network is normal, the host is responsible for allocating and dispatching operations. When the communication network is abnormal, the slave maintains the current state of operation.

[0064] The inverter UVW interface in the control cabinet of the host and slave is connected to the water pump UVW interface. The control cabinet calculates and outputs the proportional value of 0~1000 through the controller to adjust the inverter frequency 0~50Hz change, thereby adjusting the operation size of the water pump. The control cabinet calculates and outputs the proportional value of 0~1000 to the controller port corresponding to DC0-10V, and adjusts the inverter frequency 0~50Hz.

[0065] The host and each slave are designed with strong and weak electricity integration, and there are up to 7 slaves. The host and slave use RS485 interface to realize hand-in-hand communication interactive network connection.

[0066] The energy efficiency management and control platform performs visual operations on the chilled water pump energy efficiency control cabinet group. The energy efficiency management and control platform can display, record, and operate the chilled water pump energy efficiency control cabinet group. The energy efficiency management and control platform is connected to the host of the modular chilled water pump energy efficiency control cabinet group through the RS485 interface and the MODBUS-RTU protocol for data exchange.

[0067] The present invention discloses a decoupled high-efficiency central air-conditioning chilled water control system and a decoupled high-efficiency central air-conditioning chilled water control method. The signal ends of each signal probe group and valve A and valve B are connected to the host of a modular chilled water pump energy efficiency control cabinet group to perform energy efficiency control calculations. The flow rate of the chilled water circuit is compensated by adjusting valve A and valve B. Each signal probe group is used to collect temperature and pressure values ​​at the corresponding pipeline. The pressure and temperature measured by the pressure sensor and temperature sensor installed on the total outlet pipe of the chilled water pump are P0 and T1 respectively. The pressure and temperature measured by the pressure sensor and temperature sensor installed on the total outlet pipe of the host group are P1 and T0 respectively. The pressure and temperature measured by the pressure sensor and temperature sensor installed on the terminal total return pipe are P2 and T2 respectively.

[0068] 1. The flow compensation logic and algorithm are as follows:

[0069] Current total traffic ΔPPV 总 = Current host traffic ΔPPV主机端 +Current terminal flow ΔPPV 末端

[0070] Among them: Current host traffic ΔPPV 主机端 =P0-P1, current terminal flow ΔPPV 末端 =P1-P2

[0071] Total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 +Terminal flow demand ΔPSV 末端

[0072] Host-side traffic demand ΔPSV 主机端 and terminal flow demand ΔPSV 末端 They are all artificial settings;

[0073] 1) If ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 , then valve A or valve B will not be regulated and maintain the current state;

[0074] 2) If ΔPPV 主机端 <ΔPSV 主机端 , ΔPPV 末端 >ΔPSV 末端 , then valve A opens and the opening gradually increases until ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 When , valve A stops increasing and maintains the current state;

[0075] 3) If ΔPPV 主机端 >ΔPSV 主机端 , ΔPPV 末端 <ΔPSV 末端 , then valve B opens and the opening gradually increases until ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 When , valve B stops increasing and maintains the current state;

[0076] 2. The energy efficiency control algorithm is as follows:

[0077] 1) Basic algorithm:

[0078] A. When the host is the target: Current total traffic ΔPPV 总 = Current host traffic ΔPPV 主机端 , total flow demand ΔPSV总 = Host-side traffic demand ΔPSV 主机端 ;

[0079] B. When the end is the target: Current total flow ΔPPV 总 = Current terminal flow ΔPPV 末端 , total flow demand ΔPSV 总 = Terminal flow demand ΔPSV 末端 ;

[0080] C. When bilateral flow is the target: Current total flow ΔPPV 总 = Current host traffic ΔPPV 主机端 +Current terminal flow ΔPPV 末端 , total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 +Terminal flow demand ΔPSV 末端 ;

[0081] 2) Load temperature difference flow correction algorithm:

[0082] A. Host-side compensation upper and lower limits calculation:

[0083] a) Host-side ΔT correction ΔP compensation upper limit = total flow demand ΔPSV 总 × Host-side ΔT correction ΔP compensation upper limit ratio;

[0084] b) Host-side ΔT correction ΔP compensation lower limit = total flow demand ΔPSV 总 × Host-side ΔT correction ΔP compensation lower limit ratio;

[0085] B. Calculation of upper and lower limits of terminal compensation:

[0086] a) Terminal ΔT correction ΔP compensation upper limit = total flow demand ΔPSV 总 × The upper limit ratio of ΔT correction ΔP compensation at the end;

[0087] b) Terminal ΔT correction ΔP compensation lower limit = total flow demand ΔPSV 总 × Terminal ΔT correction ΔP compensation lower limit ratio;

[0088] C. If the A or B valve compensation is turned on, the calculation starts, otherwise the compensation value is 0:

[0089] Among them, the host end sampling temperature difference = T1-T0, the terminal end sampling temperature difference = T2-T1, and the standard working condition temperature difference between the host end and the terminal end adopts the set standard value;

[0090] a) When the host-side sampled temperature difference is less than the host-side standard operating temperature difference, the host-side ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, it is reduced by the set fixed value, and the cycle repeats. When the host-side ΔT correction ΔP compensation value is less than or equal to the host-side ΔT correction ΔP compensation lower limit value, the reduction of the set fixed value is stopped;

[0091] b) When the host-side sampled temperature difference is greater than the host-side standard operating temperature difference, the host-side ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, the set fixed value is added, and the cycle repeats. When the host-side ΔT correction ΔP compensation value is greater than or equal to the host-side ΔT correction ΔP compensation upper limit value, the set fixed value is stopped;

[0092] c) When the terminal sampling temperature difference is less than the terminal standard operating temperature difference, the terminal ΔT repair ΔP compensation value starts from 0, and when the custom pulse time is reached, it is reduced by the set fixed value, and the cycle repeats. When the terminal ΔT repair ΔP compensation value is less than or equal to the terminal ΔT repair ΔP compensation lower limit, the fixed value is stopped from being reduced;

[0093] d) When the terminal sampling temperature difference is greater than the terminal standard operating temperature difference, the terminal ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, the set fixed value is added, and the cycle is repeated. When the terminal ΔT correction ΔP compensation value is greater than or equal to the terminal ΔT correction ΔP compensation upper limit value, the set fixed value is stopped;

[0094] In this embodiment, the custom pulse time is 60s, and the set fixed value is 1Kpa.

[0095] A valve or B valve compensation opening operation result: the actual flow rate of the pump is always measured by the current total flow ΔPPV 总 ΔPSV vs. total flow demand 总 By comparing the opening of valve A or valve B, the current total flow rate ΔPPV can be guaranteed. 总 = Total flow demand ΔPSV 总 , if the current total flow ΔPPV 总 = Total flow demand ΔPSV 总 , the pump maintains the current work. The range of the opening of valve A or valve B is 0~100%, and the amount of each change is 0.5% of the maximum opening.

[0096] The energy efficiency control algorithm also includes a temperature trend prediction and compensation algorithm, as follows:

[0097] When the T2 sampling temperature is less than or equal to the starting temperature, the standard operating temperature difference increases by 0.1°C every minute;

[0098] When the T2 sampling temperature is greater than or equal to the end temperature, the standard operating temperature difference decreases by 0.1°C every minute;

[0099] The starting temperature and the ending temperature are both set values. In this embodiment, the standard operating temperature difference between the host end and the terminal end is 5°C, the starting temperature adopts the standard operating temperature of 7°C, and the ending temperature is 12°C.

[0100] 1. The flow compensation algorithm is as follows:

[0101] Host-side traffic demand ΔPSV 主机端 is 50kPa, and the terminal flow demand ΔPSV 末端 is 50 kPa, then the total flow demand ΔPSV 总 100kPa;

[0102] (1) If the current host traffic ΔPPV 主机端 is 40 kPa, the current terminal flow rate ΔPPV 末端 is 60kPa, the current total flow ΔPPV 总 is 100 kPa, valve A opens and the opening gradually increases until the current host end flow rate ΔPPV 主机端 is 50 kPa, the current terminal flow rate ΔPPV 末端 It is 50kPa.

[0103] (2) If the current host traffic ΔPPV 主机端 is 60 kPa, the current terminal flow rate ΔPPV 末端 is 40kPa, the current total flow ΔPPV 总 is 100 kPa, valve B opens and the opening gradually increases until the current host end flow rate ΔPPV 主机端 is 50 kPa, the current terminal flow rate ΔPPV 末端 It is 50kPa.

[0104] 2. Energy efficiency control calculation is as follows:

[0105] 1) Basic algorithm:

[0106] A. When the host is the target: If the current host traffic ΔPPV 主机端 40 kPa, which is less than the host flow demand ΔPSV 主机端 If the value is 60 kPa, valve A opens and the opening gradually increases until the current host end flow rate ΔPPV 主机端 Reach 60kPa;

[0107] B. When the terminal is the target: If the current terminal flow ΔPPV 末端 60 kPa, which is less than the terminal flow demand ΔPSV 末端 If the value is 80 kPa, valve B opens and the opening gradually increases until the current host end flow rate ΔPPV 主机端 Up to 60 kPa;

[0108] C. When bilateral flow is the target: If the current host-side flow ΔPPV 主机端 is 40 kPa, the current terminal flow rate ΔPPV 末端 is 60kPa, and the host flow demand ΔPSV 主机端 is 50kPa, and the terminal flow demand ΔPSV 末端 If the flow rate at the host end is 50 kPa, valve A opens and the opening gradually increases until the current host end flow rate ΔPPV 主机端 is 50 kPa, the current terminal flow rate ΔPPV 末端 It is 50kPa.

[0109] 2) Load temperature difference flow correction algorithm:

[0110] Set the host-side ΔT correction ΔP compensation upper limit ratio, host-side ΔT correction ΔP compensation lower limit ratio, terminal ΔT correction ΔP compensation upper limit ratio, terminal ΔT correction ΔP compensation lower limit ratio to 20%, and the total flow demand ΔPSV 总 If the temperature is 100 kPa, the upper limit of the host-side ΔT correction ΔP compensation, the lower limit of the host-side ΔT correction ΔP compensation, the upper limit of the terminal ΔT correction ΔP compensation, and the lower limit of the terminal ΔT correction ΔP compensation are all 20 kPa. The standard operating temperature difference between the host and the terminal is set to 5°C.

[0111] a) When the host-side sampling temperature difference is 3°C, which is less than the host-side standard operating temperature difference of 5°C, the host-side ΔT correction ΔP compensation value starts from 0 and decreases by 1 kPa every 60 seconds, and repeats the cycle. When the host-side ΔT correction ΔP compensation value is less than or equal to the host-side ΔT correction ΔP compensation lower limit of 20 kPa, stop decreasing by 1 kPa;

[0112] b) When the host-side sampling temperature difference is 7°C, which is greater than the host-side standard operating temperature difference of 5°C, the host-side ΔT correction ΔP compensation value starts from 0 and adds 1 kPa every 60 seconds, and repeats the cycle. When the host-side ΔT correction ΔP compensation value is greater than or equal to the host-side ΔT correction ΔP compensation upper limit of 20 kPa, stop adding 1 kPa;

[0113] c) When the terminal sampling temperature difference is 3°C, which is less than the terminal standard operating temperature difference of 5°C, the terminal ΔT repair ΔP compensation value starts from 0 and decreases by 1 kPa every 60 seconds, and repeats the cycle. When the terminal ΔT repair ΔP compensation value is less than or equal to the terminal ΔT repair ΔP compensation lower limit of 20 kPa, stop decreasing 1 kPa;

[0114] d) When the terminal sampling temperature difference is 7°C, which is greater than the terminal standard operating temperature difference of 5°C, the terminal ΔT correction ΔP compensation value starts from 0 and adds 1kPa every 60s, repeating the cycle. When the terminal ΔT correction ΔP compensation value is greater than or equal to the terminal ΔT correction ΔP compensation upper limit of 20 kPa, stop adding 1kPa;

[0115] (3) Temperature trend prediction and compensation algorithm:

[0116] The starting temperature and the ending temperature are both set values. In this embodiment, the starting temperature adopts the standard working temperature of 7° C. and the ending temperature is 12° C. In this embodiment, the standard working temperature difference between the host end and the terminal end is 5° C., that is, the standard working temperature difference is 5° C.

[0117] When the T2 sampling temperature is 6.5°C, which is lower than the starting temperature of 7°C, the standard operating temperature difference is increased by 0.1°C every minute, and the standard operating temperature difference is increased to a maximum of 7°C. The load temperature difference flow correction algorithm is substituted for the calculation.

[0118] When the T2 sampling temperature is 12.5℃, which is greater than the end temperature of 12℃, the standard operating temperature difference decreases by 0.1℃ every minute, and the standard operating temperature difference is reduced to a minimum of 3℃. The load temperature difference flow correction algorithm is substituted for the calculation.

[0119] The change of standard working temperature difference directly affects the target pressure difference and the opening of valve A or valve B. For example, if the standard working temperature difference increases, the target pressure difference increases, and the opening of valve A or valve B increases.

[0120] The above embodiment is a preferred embodiment of the present invention. In other embodiments of the present invention, the custom pulse time is determined according to the on-site debugging situation. The time can be set to 60s or 120s or other according to the debugging situation. The fixed value of the addition and subtraction setting is also determined according to the on-site debugging situation. The addition and subtraction of 1KPa is the most basic change amount for this trial compensation. The fixed value of the addition and subtraction setting can also be 2KPa or other according to the debugging situation.

[0121] In other embodiments of the present invention, the temperature and pressure sampling cycles can also be flexibly set according to needs, and the amount of each change in the opening of valve A or valve B can also be flexibly set according to needs.

[0122] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. The scope of the present invention defined by the appended claims includes all equivalent substitutions and changes.

Claims

1. A decoupled high-efficiency central air-conditioning chilled water control system, comprising a terminal air-conditioning system group, a host group, and a chilled water pump group, wherein the terminal total return water pipe on the water collector of the terminal air-conditioning system group is connected to the total inlet of the chilled water pump group, the total outlet water pipe of the chilled water pump group is connected to the total inlet of the host group, and the total outlet water pipe of the host group is connected to the inlet of the water distributor of the terminal air-conditioning system group, characterized in that: An A-end flow compensation pipe is provided between the terminal total return pipe and the main unit total outlet pipe. The diameter of the A-end flow compensation pipe is smaller than that of the terminal total return pipe or the main unit total outlet pipe. A B-end flow compensation pipe is provided between the total outlet pipe of the chilled water pump and the main unit total outlet pipe. The diameter of the B-end flow compensation pipe is smaller than that of the total outlet pipe of the chilled water pump or the main unit total outlet pipe. A valve and B valve are provided on the A-end flow compensation pipe and the B-end flow compensation pipe respectively. Both valves A and B are electric valves. The decoupled high-efficiency central air-conditioning chilled water control system also includes a signal probe group, a modular chilled water pump energy efficiency control cabinet group and an energy efficiency management and control platform; The signal probe group is divided into three groups and has designated installation locations: the first group is the pressure sensor and temperature sensor installed on the main outlet pipe of the chilled water pump; The second group is the pressure sensor and temperature sensor installed on the main water outlet pipe of the main unit; The third group is a pressure sensor and a temperature sensor installed on the terminal main return water pipe; one end of the flow compensation pipe at the A end is located after the first group of signal probes and the other end is located before the second group of signal probes; one end of the flow compensation pipe at the B end is located before the second group of signal probes and the other end is located after the third group of signal probes; The modular chilled water pump energy efficiency control cabinet group includes a host and more than one slave. The cabinets of the host and each slave are equipped with a power system unit, a speed control system unit and a control system unit. The control system unit sends the calculation results to the speed control system unit. The control system units of the host and the slave are connected through a communication interaction network. The signal ends of valves A and B and each signal probe group are uniformly connected to the control system unit of the host. The signal ends of each water pump in the chilled water pump group are respectively connected to the control system unit of the host and the slave. Each host or slave is used to drive a water pump. The host is used to obtain and calculate the operating condition information of the chilled water system and allocate and dispatch the slave. When the communication network is normal, the host is responsible for allocating and dispatching operations. When the communication network is abnormal, the slave maintains the current state of operation. The energy efficiency management and control platform is connected to the host of the modular chilled water pump energy efficiency control cabinet group for data exchange; The result of the compensated opening operation of valve A or valve B: the actual flow rate of the pump is always adjusted by comparing the current total flow ΔPPVtotal with the total flow demand ΔPSVtotal to ensure that the current total flow ΔPPVtotal = the total flow demand ΔPSVtotal. If the current total flow ΔPPVtotal = the total flow demand ΔPSVtotal, the pump maintains its current work unchanged; the range of change of the opening of valve A or valve B is 0~100%, and the amount of change each time is 0.5% of the maximum opening.

2. The decoupled high-efficiency central air-conditioning chilled water control system according to claim 1 is characterized in that: The host and each slave are designed with integrated strong and weak electricity, and there are up to 7 slaves.

3. The decoupled high-efficiency central air-conditioning chilled water control system according to claim 1 is characterized in that: The host and slave use RS485 interface to realize hand-in-hand communication interactive network connection.

4. A decoupled high-efficiency central air-conditioning chilled water control system and a decoupled high-efficiency central air-conditioning chilled water control method, characterized in that: Connect the signal ends of each signal probe group and valve A and valve B to the host of the modular chilled water pump energy efficiency control cabinet group to perform energy efficiency control calculations, and compensate the flow of the chilled water circuit by adjusting valve A and valve B. Each signal probe group is used to collect the temperature and pressure values ​​at the corresponding pipeline. The pressure and temperature measured by the pressure sensor and temperature sensor installed on the total outlet pipe of the chilled water pump are P0 and T1 respectively, the pressure and temperature measured by the pressure sensor and temperature sensor installed on the total outlet pipe of the host group are P1 and T0 respectively, and the pressure and temperature measured by the pressure sensor and temperature sensor installed on the terminal total return pipe are P2 and T2 respectively; 1. The flow compensation logic and algorithm are as follows: Current total traffic ΔPPV 总 = Current host traffic ΔPPV 主机端 +Current terminal flow ΔPPV 末端 Among them: Current host traffic ΔPPV 主机端 =P0-P1, current terminal flow ΔPPV 末端 =P1-P2 Total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 +Terminal flow demand ΔPSV 末端 Host-side traffic demand ΔPSV 主机端 and terminal flow demand ΔPSV 末端 They are all artificial settings; If ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 , then valve A or valve B will not be regulated and maintain the current state; If ΔPPV 主机端 <ΔPSV 主机端 , ΔPPV 末端 >ΔPSV 末端 , then valve A opens and the opening gradually increases until ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 When , valve A stops increasing and maintains the current state; If ΔPPV 主机端 >ΔPSV 主机端 , ΔPPV 末端 <ΔPSV 末端 , then valve B opens and the opening gradually increases until ΔPPV 主机端 =ΔPSV 主机端 , ΔPPV 末端 =ΔPSV 末端 When , valve B stops increasing and maintains the current state; 2. The energy efficiency control algorithm is as follows: 1) Basic algorithm: A. When the host is the target: Current total traffic ΔPPV 总 = Current host traffic ΔPPV 主机端 , total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 ; B. When the end is the target: Current total flow ΔPPV 总 = Current terminal flow ΔPPV 末端 , total flow demand ΔPSV 总 = Terminal flow demand ΔPSV 末端 ; C. When bilateral flow is the target: Current total flow ΔPPV 总 = Current host traffic ΔPPV 主机端 +Current terminal flow ΔPPV 末端 , total flow demand ΔPSV 总 = Host-side traffic demand ΔPSV 主机端 +Terminal flow demand ΔPSV 末端 ; 2) Load temperature difference flow correction algorithm: A. Host-side compensation upper and lower limits calculation: a) Host-side ΔT correction ΔP compensation upper limit = total flow demand ΔPSV 总 × Host-side ΔT correction ΔP compensation upper limit ratio; b) Host-side ΔT correction ΔP compensation lower limit = total flow demand ΔPSV 总 × Host-side ΔT correction ΔP compensation lower limit ratio; B. Calculation of upper and lower limits of terminal compensation: a) Terminal ΔT correction ΔP compensation upper limit = total flow demand ΔPSV 总 × The upper limit ratio of ΔT correction ΔP compensation at the end; b) Terminal ΔT correction ΔP compensation lower limit = total flow demand ΔPSV 总 × Terminal ΔT correction ΔP compensation lower limit ratio; C. If the A or B valve compensation is turned on, the calculation starts, otherwise the compensation value is 0: Among them, the host end sampling temperature difference = T1-T0, the terminal end sampling temperature difference = T2-T1, and the standard working condition temperature difference between the host end and the terminal end adopts the set standard value; a) When the host-side sampled temperature difference is less than the host-side standard operating temperature difference, the host-side ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, it is reduced by the set fixed value, and the cycle repeats. When the host-side ΔT correction ΔP compensation value is less than or equal to the host-side ΔT correction ΔP compensation lower limit value, the reduction of the set fixed value is stopped; b) When the host-side sampled temperature difference is greater than the host-side standard operating temperature difference, the host-side ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, the set fixed value is added, and the cycle repeats. When the host-side ΔT correction ΔP compensation value is greater than or equal to the host-side ΔT correction ΔP compensation upper limit value, the set fixed value is stopped; c) When the terminal sampling temperature difference is less than the terminal standard operating temperature difference, the terminal ΔT repair ΔP compensation value starts from 0, and when the custom pulse time is reached, it is reduced by the set fixed value, and the cycle repeats. When the terminal ΔT repair ΔP compensation value is less than or equal to the terminal ΔT repair ΔP compensation lower limit, the fixed value is stopped from being reduced; d) When the terminal sampling temperature difference is greater than the terminal standard operating temperature difference, the terminal ΔT correction ΔP compensation value starts from 0, and when the custom pulse time is up, the set fixed value is added, and the cycle is repeated. When the terminal ΔT correction ΔP compensation value is greater than or equal to the terminal ΔT correction ΔP compensation upper limit value, the set fixed value is stopped; A valve or B valve compensation opening operation result: the actual flow rate of the pump is always measured by the current total flow ΔPPV 总 ΔPSV vs. total flow demand 总 By comparing the opening of valve A or valve B, the current total flow rate ΔPPV can be guaranteed. 总 = Total flow demand ΔPSV 总 , if the current total flow ΔPPV 总 = Total flow demand ΔPSV 总 , the water pump maintains the current work unchanged.

5. The decoupled high-efficiency central air-conditioning chilled water control method according to claim 4 is characterized in that: The energy efficiency control algorithm also includes a temperature trend prediction and compensation algorithm, as follows: When the T2 sampling temperature is less than or equal to the starting temperature, the standard operating temperature difference increases by 0.1°C every minute; When the T2 sampling temperature is greater than or equal to the end temperature, the standard operating temperature difference decreases by 0.1°C every minute; The starting temperature and ending temperature are both set values.

6. The decoupled high-efficiency central air-conditioning chilled water control method according to claim 5 is characterized in that: The standard operating temperature difference between the host end and the terminal end is 5°C, the starting temperature is 7°C, and the ending temperature is 12°C.

7. The decoupled high-efficiency central air-conditioning chilled water control method according to claim 4 is characterized in that: The custom pulse time is 60-120s.

8. The decoupled high-efficiency central air-conditioning chilled water control method according to claim 4 is characterized in that: The set fixed value is 1Kpa.

9. The decoupled high-efficiency central air-conditioning chilled water control method according to claim 4, characterized in that: The range of the opening of valve A or valve B is 0~100%, and the amount of each change is 0.5% of the maximum opening.

10. The decoupled high-efficiency central air-conditioning chilled water control method according to claim 4, characterized in that: The sampling cycle of temperature and pressure is 1s / time.

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