Energy-saving control method based on water chilling unit

Abstract

The invention relates to the technical field of energy-saving control, in particular to an energy-saving control method based on a water chilling unit, and the method comprises the steps: collecting parameters through an energy consumption metering module, and transmitting the parameters to a management module; the management module analyzes and outputs a control instruction to the control module by using the control system according to the collected parameters; the operation of the water chilling unit is controlled through the control module according to the control instruction, control information is transmitted to the management module, and the control over the operation actions of the water chilling unit comprises the setting of the outlet water temperature, the opening degree of a proportional-integral regulating valve, the start-stop or frequency of a chilled water circulating pump / cooling water circulating pump and the start-stop of a cooling tower. The system has the effects of automatic adjustment, intelligent scheduling and energy saving.

Description

Technical Field

[0001] The present invention relates to the technical field of energy-saving control, and in particular to an energy-saving control method based on a chiller. Background Art

[0002] At present, the management of air-conditioning rooms in most public buildings is extensive. The control of chillers can only control the start and stop of the units, with low control efficiency, and most of them are manually set, with low automation. In addition, the set temperature cannot be adjusted in real time, so the chillers are always in operation. The units and systems have high energy consumption, resulting in a lot of energy and manpower waste. According to the current national dual-carbon policy requirements for carbon reduction indicators, many public buildings do not meet the standards and cannot meet the requirements of energy conservation and carbon reduction. Summary of the invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides an energy-saving control method based on a chiller.

[0004] The technical solution of the present invention is:

[0005] The energy consumption metering module collects various parameters and transmits them to the management module;

[0006] The management module uses the control system to analyze and output control instructions to the control module based on the collected parameters;

[0007] The operation of the chiller is controlled by the control module according to the control instructions and the control information is transmitted to the management module, wherein the operation actions of controlling the chiller include setting the outlet water temperature, the opening of the proportional-integral control valve, the start and stop or frequency of the chilled water circulation pump / cooling water circulation pump, and the start and stop of the cooling tower.

[0008] Furthermore, the parameters collected by the energy consumption metering module include power consumption, chilled water supply and return water temperatures, cooling water supply and return water temperatures, building indoor temperature, and building outdoor temperature.

[0009] Further, the control system analysis step includes:

[0010] Set the cooling mode energy-saving intervention conditions and cooling mode energy-saving non-intervention conditions;

[0011] According to the relationship between indoor temperature Tn1, indoor lower limit setting temperature Tmin1, chilled water outlet temperature T1, and chilled water return temperature T2, four-level analysis and judgment conditions are set, which are:

[0012] If the energy-saving intervention conditions of the corresponding mode are met, energy-saving 1 is started; otherwise, energy-saving is not intervened;

[0013] If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1 and lasts for more than 30 seconds, and T2>T1+1, energy saving 2 is activated; otherwise, energy saving does not intervene;

[0014] If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1 and lasts for more than 30 seconds, and T2>T1+1, energy saving 3 is activated; otherwise, energy saving 1 is activated;

[0015] If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1, energy saving 3 is started; otherwise, energy saving 2 is started.

[0016] Furthermore, the cooling mode energy-saving intervention conditions must meet the following conditions at the same time:

[0017] Mode setting M1 = cooling;

[0018] Energy saving switch M3 = on;

[0019] Model selection M4 = air cooling module;

[0020] Indoor temperature Tn1 ≤ indoor lower limit setting temperature Tmin1;

[0021] Chilled water return temperature T2>chilled water outlet temperature T1+1;

[0022] The non-intervention conditions for energy saving in cooling mode are:

[0023] Energy-saving switch M3 = off or indoor temperature Tn1> indoor upper limit setting temperature Tmax1.

[0024] Furthermore, in the control system analysis step, data is collected in real time and the energy-saving mode switching intervals are the same.

[0025] Furthermore, the energy-saving mode switching interval is set to 5 minutes.

[0026] Furthermore, the optimal outlet water temperature of the chiller is set, the load rate of the unit is calculated through the data collected by the energy consumption metering module, the difference between the current outlet water temperature and the optimal outlet water temperature of the unit is calculated through the collected data, and the set outlet water temperature is adjusted so that the current outlet water temperature of the chiller is closer to the optimal outlet water temperature.

[0027] Furthermore, to achieve temperature control of the chiller, the chiller outlet water temperature is set as follows:

[0028]

[0029] Where: Tchw,out,set: chilled water outlet set temperature;

[0030] Tchw,out,max: maximum chilled water outlet temperature;

[0031] Tchw,out,min: minimum chilled water outlet temperature;

[0032] Qmax: maximum cooling capacity;

[0033] Qmin: minimum cooling capacity;

[0034] Qf: actual load cooling capacity.

[0035] Furthermore, in order to achieve the temperature control of the chiller, the chiller pump frequency control is set according to the following formula:

[0036]

[0037] Where: DPdes: pump bottom line control frequency;

[0038] DPset: water pump control frequency setting;

[0039] b1: control coefficient;

[0040] Qmax: maximum cooling capacity;

[0041] Qmin: minimum cooling capacity;

[0042] Qf: actual load cooling capacity.

[0043] The energy-saving control method based on a chiller of the present invention has the following advantages:

[0044] 1. According to the actual indoor temperature and demand of the building, adjust the cooling setting of the air-conditioning equipment to keep the indoor temperature within a comfortable range.

[0045] 2. According to the temperature, humidity and other data inside and outside the building, the operating status of the terminal air-conditioning equipment of the chiller unit is automatically adjusted, the operating parameters are automatically adjusted, the unit load rate is adjusted, and the optimal energy efficiency point state is automatically found.

[0046] 3. The energy consumption metering module, management module and metering module of the present invention form an integrated system, which not only helps to increase revenue and reduce expenditure and improve energy utilization efficiency, but also realizes intelligent scheduling of power supply and demand through intelligent management means, optimizes energy utilization efficiency, and reduces dependence on traditional energy sources such as coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a logic diagram of the refrigeration mode of the energy-saving control method of the chiller according to the present invention;

[0048] Figure 2 It is a temperature control model of the energy-saving control method of the chiller according to the present invention. DETAILED DESCRIPTION

[0049] To facilitate those skilled in the art to understand the present invention, specific implementations of the present invention are described below with reference to the accompanying drawings.

[0050] Embodiment 1

[0051] The energy-saving control method based on a chiller of the present invention comprises:

[0052] The energy consumption metering module collects various parameters and transmits them to the management module;

[0053] The management module uses the control system to analyze and output control instructions to the control module based on the collected parameters;

[0054] The operation of the chiller is controlled by the control module according to the control instructions and the control information is transmitted to the management module, wherein the operation actions of controlling the chiller include setting the outlet water temperature, the opening of the proportional-integral control valve, the start and stop or frequency of the chilled water circulation pump / cooling water circulation pump, and the start and stop of the cooling tower.

[0055] The parameters collected by the energy consumption metering module include power consumption, chilled water supply and return water temperature, cooling water supply and return water temperature, building indoor temperature, building outdoor temperature, etc. The parameters collected by the energy consumption metering module are transmitted to the management module via the modbus protocol to the mqtt protocol.

[0056] The control system analysis steps of the management model include:

[0057] Set the cooling mode energy-saving intervention conditions and cooling mode energy-saving non-intervention conditions;

[0058] According to the relationship between indoor temperature Tn1, indoor lower limit setting temperature Tmin1, chilled water outlet temperature T1, and chilled water return temperature T2, four-level analysis and judgment conditions are set, which are:

[0059] S1: If the energy-saving intervention conditions of the corresponding mode are met, energy-saving 1 is started; otherwise, energy-saving is not intervened;

[0060] S2: If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1 and lasts for more than 30 seconds, and T2>T1+1, energy saving 2 is activated; otherwise, energy saving does not intervene;

[0061] S3. If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1 and lasts for more than 30 seconds, and T2>T1+1, energy saving 3 is activated; otherwise, energy saving 1 is activated;

[0062] S4. If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1, energy saving 3 is started; otherwise, energy saving 2 is started.

[0063] Among them, the judgment conditions of setting S2 and S3 are the same, because the temperature T1 of the above process changes in real time, the same conditions represent the same start-up intervals of different energy-saving modes, or similar temperatures lasting for more than 30S represent a stable temperature state, which is more accurate and representative than conventional real-time control.

[0064] Among them, the energy-saving intervention conditions of the cooling mode must meet the following conditions at the same time:

[0065] Mode setting M1 = cooling;

[0066] Energy saving switch M3 = on;

[0067] Model selection M4 = air cooling module;

[0068] Indoor temperature Tn1 ≤ indoor lower limit setting temperature Tmin1;

[0069] Chilled water return temperature T2>chilled water outlet temperature T1+1;

[0070] The temperature difference of 1°C between the chilled water return temperature T2 and the chilled water outlet temperature T1 is used to ensure the output of cooling capacity.

[0071] The non-intervention conditions for energy saving in cooling mode are:

[0072] Energy-saving switch M3 = off or indoor temperature Tn1> indoor upper limit setting temperature Tmax1.

[0073] In the control system analysis step, data is collected in real time, and the energy-saving mode switching interval is the same, which is set to 5 minutes.

[0074] Set the optimal outlet water temperature of the chiller, calculate the load rate of the unit through the data collected by the energy consumption metering module, calculate the difference between the current chilled water outlet temperature and the optimal outlet water temperature of the unit through the collected data, and adjust the set outlet water temperature so that the current chilled water outlet temperature of the chiller is closer to the optimal outlet water temperature of the chiller. Through the above settings, the automatic adjustment function is realized.

[0075] In order to achieve temperature control, the present invention establishes an optimization control model for the chilled water side, and controls in the following manner:

[0076]

[0077] Where: Tchw,out,set: chilled water outlet set temperature;

[0078] Tchw,out,max: maximum chilled water outlet temperature;

[0079] Tchw,out,min: minimum chilled water outlet temperature;

[0080] Qmax: maximum cooling capacity;

[0081] Qmin: minimum cooling capacity;

[0082] Qf: actual load cooling capacity.

[0083] The chiller pump frequency control is set as follows:

[0084]

[0085] Where: DPdes: pump bottom line control frequency;

[0086] DPset: water pump control frequency setting;

[0087] b1: control coefficient;

[0088] Qmax: maximum cooling capacity;

[0089] Qmin: minimum cooling capacity;

[0090] Qf: actual load cooling capacity.

[0091] Through the above settings, the cooling settings of the air-conditioning equipment are adjusted according to the actual indoor temperature and demand. When the actual indoor temperature is high, the outlet water temperature of the chiller is automatically set lower. When the actual indoor temperature is low, the outlet water temperature of the chiller is automatically set higher to keep the indoor temperature within a comfortable range.

[0092] Embodiment 2

[0093] On the basis of the first embodiment, the energy-saving control method based on the chiller of the present invention also has the functions of time control and timer switch.

[0094] By making manual presets in advance, or by setting up a matching regular time control table, reasonably adjusting the opening and closing times of the chiller terminal air-conditioning equipment, or reasonably adjusting the temperature settings of the air-conditioning equipment, unnecessary energy waste can be avoided.

[0095] End users of chillers can preset the start and stop times of air conditioning equipment to achieve automatic control.

[0096] Embodiment 3

[0097] On the basis of the second embodiment, the energy-saving control method based on the chiller of the present invention also has personalized intelligent management and remote control functions.

[0098] By connecting with other smart devices, the temperature and air volume can be automatically adjusted to provide a personalized comfort experience based on the user's behavior and needs. The operating status of the air conditioning equipment can be monitored and adjusted anytime and anywhere through mobile phones and other terminal devices.

[0099] The energy-saving control method based on the chiller of the present invention includes three modules: energy consumption measurement, control and management, forming an integrated system of comprehensive energy consumption sub-item measurement, control and management. This system not only helps enterprises to increase revenue and reduce expenditure, improve energy utilization efficiency, but also realizes intelligent scheduling of power supply and demand through intelligent management means, optimizes energy utilization efficiency, and reduces dependence on traditional energy sources such as coal.

[0100] The above-described embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An energy-saving control method based on a chiller, characterized in that: The energy consumption metering module collects various parameters and transmits them to the management module; The management module uses the control system to analyze and output control instructions to the control module based on the collected parameters; The operation of the chiller is controlled by the control module according to the control instructions and the control information is transmitted to the management module, wherein the operation actions of controlling the chiller include setting the outlet water temperature, the opening of the proportional-integral control valve, the start and stop or frequency of the chilled water circulation pump / cooling water circulation pump, and the start and stop of the cooling tower.

2. The energy-saving control method based on a chiller according to claim 1, characterized in that: The parameters collected by the energy consumption metering module include power consumption, chilled water supply and return water temperature, cooling water supply and return water temperature, building indoor temperature, and building outdoor temperature.

3. The energy-saving control method and control method based on a chiller according to claim 1, characterized in that: The control system analysis steps include: Set the cooling mode energy-saving intervention conditions and cooling mode energy-saving non-intervention conditions; According to the relationship between indoor temperature Tn1, indoor lower limit setting temperature Tmin1, chilled water outlet temperature T1, and chilled water return temperature T2, four-level analysis and judgment conditions are set, which are: If the energy-saving intervention conditions of the corresponding mode are met, energy-saving 1 is started; otherwise, energy-saving is not intervened; If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1 and lasts for more than 30 seconds, and T2>T1+1, energy saving 2 is activated; otherwise, energy saving does not intervene; If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1 and lasts for more than 30 seconds, and T2>T1+1, energy saving 3 is activated; otherwise, energy saving 1 is activated; If the indoor temperature Tn1 ≤ the indoor lower limit setting temperature Tmin1, energy saving 3 is started; otherwise, energy saving 2 is started.

4. The energy-saving control method based on a chiller according to claim 3 is characterized in that: The energy-saving intervention conditions in cooling mode must be met at the same time: Mode setting M1 = cooling; Energy saving switch M3 = on; Model selection M4 = air cooling module; Indoor temperature Tn1 ≤ indoor lower limit setting temperature Tmin1; Chilled water return temperature T2>chilled water outlet temperature T1+1; The non-intervention conditions for energy saving in cooling mode are: Energy-saving switch M3 = off or indoor temperature Tn1> indoor upper limit setting temperature Tmax1.

5. The energy-saving control method based on a chiller according to claim 4 is characterized in that: In the control system analysis step, data is collected in real time and the energy-saving mode switching intervals are the same.

6. The energy-saving control method based on a chiller according to claim 5, characterized in that: The energy-saving mode switching interval is set to 5 minutes.

7. The energy-saving control method based on a chiller according to claim 1, characterized in that: Set the optimal outlet water temperature of the chiller, calculate the load rate of the unit through the data collected by the energy consumption metering module, calculate the difference between the current outlet water temperature and the optimal outlet water temperature of the unit through the collected data, adjust the set outlet water temperature, and make the current outlet water temperature of the chiller closer to the optimal outlet water temperature.

8. The energy-saving control method based on a chiller according to claim 1, characterized in that: To achieve temperature control of the chiller, the chiller outlet water temperature is set as follows: Where: Tchw,out,set: chilled water outlet set temperature; Tchw,out,max: maximum chilled water outlet temperature; Tchw,out,min: minimum chilled water outlet temperature; Qmax: maximum cooling capacity; Qmin: minimum cooling capacity; Qf: actual load cooling capacity.

9. The energy-saving control method based on a chiller according to claim 8, characterized in that: To achieve temperature control of the chiller, the chiller pump frequency control is set according to the following formula: Where: DPdes: pump bottom line control frequency; DPset: water pump control frequency setting; b1: control coefficient; Qmax: maximum cooling capacity; Qmin: minimum cooling capacity; Qf: actual load cooling capacity.

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