Multi-energy complementary source, network, load, storage and control integrated green low-carbon air conditioning system

Abstract

The invention relates to the technical field of energy, and discloses a multi-energy complementary source network load storage control integrated green low-carbon air conditioning system which comprises a water ring pipe network circulating water pump and a plurality of subsystems, and the water ring pipe network circulating water pump is connected with the subsystems to form a water ring water supply pipeline; the preset flow monitoring method for the water ring water supply pipeline comprises the steps that the operation frequency of a water ring pipe network circulating water pump is adjusted, and data during operation of an air conditioning system are collected; fitting the acquired data by using a least square method to respectively obtain H-Q and N-Q characteristic curves; correcting the characteristic curve according to the influence of water supply temperature and frequency; and taking the corrected characteristic curve as a water flow monitoring model to monitor the water flow of the water ring water supply pipeline. According to the method, the least square method is used for fitting the operation data, the obtained H-Q and N-Q characteristic curves are used as the water flow monitoring model after being corrected, the system flow value is indirectly obtained, pipelines are not damaged, the equipment investment is small, and rapid measurement of the water flow of the air conditioning system is achieved.

Description

Technical Field

[0001] The present invention relates to the field of energy technology, and in particular to a multi-energy complementary source-grid-load-storage-control integrated green low-carbon air-conditioning system. Background Art

[0002] When there is a lot of waste heat inside the building and there are large differences in the use time of air conditioners in different areas, the traditional centralized air conditioning system has problems of mismatch between supply and demand and high operating costs under various working conditions. In addition, when there are both cooling and heating load demands inside the building, for example, the air conditioning system is divided into inner and outer areas according to the depth of the building, with cooling in the inner area and heating in the outer area; the simultaneous cooling and heating load demands can generally be solved through a four-pipe air conditioning system, a water ring system, etc. However, there are problems such as high initial investment, inability to fully utilize waste heat in the building, and low overall system energy efficiency.

[0003] At the same time, the flow measurement method of the air conditioning water system is mainly to install flow meters and flow sensors in the pipeline. In recent years, the research has mainly focused on how to improve the accuracy of flow sensors. These methods of directly measuring flow will increase the equipment investment of the air conditioning system. Especially driven by the current situation of pursuing high accuracy, the installation of flow meters greatly increases the cost of the entire test system. At the same time, it will also damage the original pipeline and increase the system resistance, which is contrary to the goal of building energy conservation. Therefore, it is necessary to achieve rapid measurement of the water flow of the air conditioning system without damaging the pipeline, with less equipment investment and maintaining a certain accuracy. Summary of the invention

[0004] The present invention provides a multi-energy complementary source-grid-load-storage-control integrated green and low-carbon air-conditioning system. Based on a water ring network circulating water pump and a water ring water supply pipeline, the pressure difference and water supply temperature data during the operation of the air-conditioning system are fitted by the least squares method to obtain HQ and NQ characteristic curves respectively. The two fitting curves are corrected and used as a water flow monitoring model to indirectly obtain the system flow value. The system does not damage the pipeline and has less equipment investment, thereby realizing rapid measurement of the water flow of the air-conditioning system.

[0005] The present invention provides a multi-energy complementary source-grid-load-storage-control integrated green low-carbon air conditioning system, comprising a water ring network circulating water pump and a plurality of subsystems, wherein the water ring network circulating water pump connects the plurality of subsystems to form a water ring water supply pipeline, and the water ring water supply pipeline is provided with a temperature sensor and a pressure difference sensor for collecting water supply temperature and pressure difference;

[0006] The water ring water supply pipeline adopts a preset flow monitoring method to monitor the water flow of the water ring water supply pipeline. The preset flow monitoring method includes:

[0007] S1. Adjust the operating frequency of the water circulation pump of the water ring network to a set frequency, and collect the pressure difference and water supply temperature data when the air conditioning system is running;

[0008] S2. Fit the collected data using the least square method to obtain the HQ characteristic curve and the NQ characteristic curve respectively;

[0009] S3, modifying the HQ characteristic curve and the NQ characteristic curve according to the influence of the water supply temperature and frequency, so that the fitting curve can be applied to any water supply temperature or any frequency;

[0010] S4. Using the modified HQ characteristic curve and NQ characteristic curve as a water flow monitoring model, and using the water flow monitoring model to monitor the water flow of the water ring water supply pipeline.

[0011] Furthermore, the step S2 specifically includes:

[0012] The flow measurement function relationship based on the air conditioning system and the water ring network circulating water pump is:

[0013] Q=f(ρg,H,N,D,n)

[0014] Among them, Q is the flow rate of the water ring network circulating water pump delivered to the pipeline, m 3 / h; ρ is the density of the transported liquid kg / m 3 ; g is the acceleration of free fall, m / s 2 ; H is the head of the water ring network circulating water pump, m, which can be obtained by measuring the pressure difference; N is the shaft power of the water ring network circulating water pump, kW; D is the impeller diameter, the water ring network circulating water pump is fixed, and the impeller diameter will not change; n is the speed, r / min;

[0015] The performance curves of the water ring network circulating water pump include the HQ curve and the NQ curve. The performance curves of the centrifugal water pump with backward impeller are obtained by experimental measurement at a fixed speed with clean water of a set temperature under normal pressure. Among them, for the HQ curve, the flow rate increases and the head continues to decrease; for the NQ curve, the flow rate increases, and the shaft power first increases and then tends to remain unchanged.

[0016] According to the trends of HQ curve and NQ curve, the HQ curve of the circulating water pump of the water ring network is fitted with the quadratic curve of the least squares method, that is:

[0017] H=α0+α1Q+α2Q 2

[0018] The NQ curve is fitted with a cubic curve using the least squares method, namely:

[0019] N=β0+β1Q+β2Q 2 +β3Q 3

[0020] Among them, α0 and β0 are fitting constants; α1, α2, β1, β2, and β3 are fitting coefficients;

[0021] The HQ curve and NQ curve are obtained through the above fitting process, which can realize the identification of the flow rate Q of the water ring water supply pipeline.

[0022] Furthermore, in step S3, the factors affecting the characteristic curve of the water ring network circulating water pump include the speed n, the water supply temperature t G , impeller diameter D and pipe network pressure;

[0023] The pump flow rate Q, head H, and shaft power N are all related to the speed n, and the following relationship is obtained:

[0024]

[0025] Wherein, f is the frequency of the circulating water pump in the water ring network, and the subscripts 1 and 2 represent different operating conditions.

[0026] Since the speed of the circulating water pump in the water ring network is directly proportional to the frequency, if the flow rate Q, head H, and shaft power N of the water pump at a certain frequency are known, the flow rate Q, head H, and shaft power N at any frequency can be obtained. Similarly, if the water pump characteristic curve at a certain frequency is fitted, the water pump characteristic curves at other frequencies can also be obtained.

[0027] Furthermore, the water supply temperature t G The factors that affect the density and viscosity of water are the head H and flow rate Q of the water ring network circulating water pump and the density. The shaft power N increases with the increase of density. The factors affecting the HQ characteristic curve of the water ring network circulating water pump are the speed n, and the factors affecting the NQ characteristic curve are the speed n and the water supply temperature t. G .

[0028] Further, the multiple subsystems include a closed cooling tower, a distributed water source heat pump system for office tower 1, a buried pipe heat exchange system, a data room waste heat recovery system, a gas boiler, a water source heat pump system for part of the podium, a distributed water source heat pump system for office tower 2, and a multi-effect full-process water treatment device;

[0029] The closed cooling tower, the distributed water source heat pump system of office tower one, the buried pipe heat exchange system, the data room waste heat recovery system, the gas boiler, the podium water source heat pump system, and the distributed water source heat pump system of office tower two are all connected to the energy management system, and are connected to the water ring network circulating water pump through a first pipeline and to the multi-effect full-process water treatment device through a second pipeline. The first pipeline and the second pipeline together form the water ring water supply pipeline. The multi-effect full-process water treatment device is connected to the water ring network circulating water pump, and the water ring network circulating water pump is connected to the energy management system.

[0030] Furthermore, energy meters are installed between the closed cooling tower, the distributed water source heat pump system of office tower one, the buried pipe heat exchange system, the data room waste heat recovery system, the gas boiler, the water source heat pump system of the podium, the distributed water source heat pump system of office tower two and the second pipeline; all energy meters are connected to the energy management system.

[0031] Furthermore, there are two gas boilers, both of which are connected to the energy management system, and the two gas boilers are respectively equipped with their own energy meters.

[0032] The beneficial effects of the present invention are:

[0033] 1. Use the characteristic curve of the water ring network circulating water pump as a water flow monitoring model to measure the water flow of the air-conditioning system. This is fast, effective, and low-cost. The flow value can be obtained while the system is running. No other instruments need to be installed. Only the existing pressure difference sensor and temperature sensor of the system are required, which has little impact on the pipeline.

[0034] 2. The flow rate is solved according to the HQ and NQ characteristic curves. The accuracy of identification through the HQ characteristic curve is high and the error range is stable. In the method of identifying the flow rate with the NQ characteristic curve, the power value is easy to obtain and the error is low when operating at high frequency.

[0035] 3. The indirect identification of flow and heat based on pressure difference breaks the limitations of the existing energy consumption monitoring platform and can also play an important role in variable flow energy-saving technology. It has certain practicality and has broad prospects in the use of various water pumps and other power components. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the flow of water flow monitoring in the present invention.

[0037] Figure 2 It is a schematic diagram of the characteristic curve of the circulating water pump of the water ring network in the present invention.

[0038] Figure 3 It is a structural schematic diagram of the air conditioning system in the present invention.

[0039] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0041] The present invention provides a multi-energy complementary source-grid-load-storage-control integrated green and low-carbon air-conditioning system, comprising a water ring network circulating water pump and multiple subsystems, wherein the water ring network circulating water pump connects multiple subsystems to form a water ring water supply pipeline, and a temperature sensor and a pressure difference sensor are arranged on the water ring water supply pipeline for collecting water supply temperature and pressure difference.

[0042] In view of the limitations of the flow and heat supply measurement of the air conditioning water system, the present invention uses power to obtain the power-flow fitting characteristic curve; based on the power component water pump, the head-flow fitting characteristic curve is obtained. Through the two fitting curves, the system flow value is indirectly obtained respectively, and the analysis and comparison are carried out to propose an online identification method of flow and heat.

[0043] like Figure 1 As shown, the water ring water supply pipeline adopts a preset flow monitoring method to monitor the water flow of the water ring water supply pipeline, and the preset flow monitoring method includes:

[0044] S1. Adjust the operating frequency of the water circulation pump of the water ring network to a set frequency, and collect the pressure difference and water supply temperature data when the air conditioning system is running.

[0045] S2. Fit the collected data using the least square method to obtain the HQ characteristic curve and the NQ characteristic curve respectively. The flow measurement function relationship based on the air conditioning system and the water ring network circulating water pump is:

[0046] Q=f(ρg,H,N,D,n)

[0047] Among them, Q is the flow rate of the water ring network circulating water pump delivered to the pipeline, m 3 / h; ρ is the density of the transported liquid kg / m 3 ; g is the acceleration of free fall, m / s 2 ; H is the head of the water ring network circulating water pump, m, which can be obtained by measuring the pressure difference; N is the shaft power of the water ring network circulating water pump, kW; D is the impeller diameter, the water ring network circulating water pump is fixed, and the impeller diameter will not change; n is the speed, r / min;

[0048] The performance curves of the water ring network circulating water pump include HQ curve and NQ curve. The performance curve of the centrifugal water pump with backward impeller is obtained by experimental measurement at a fixed speed with clean water of set temperature under normal pressure, such as Figure 2 As shown; for the HQ curve, the flow rate increases and the head continues to decrease; for the NQ curve, the flow rate increases, the shaft power first increases and then tends to remain unchanged;

[0049] According to the trends of HQ curve and NQ curve, the HQ curve of the circulating water pump of the water ring network is fitted with the quadratic curve of the least squares method, that is:

[0050] H=α0+α1Q+α2Q 2

[0051] The NQ curve is fitted with a cubic curve using the least squares method, namely:

[0052] N=β0+β1Q+β2Q 2 +β3Q 3

[0053] Among them, α0 and β0 are fitting constants; α1, α2, β1, β2, and β3 are fitting coefficients;

[0054] For the obtained finite discrete points, the least square method can be used to quickly realize curve fitting. Through the above fitting process, two types of fitting curves can be obtained, which can realize the identification of the flow rate Q of the air conditioning water system. The data of the pump head H, shaft power N, and flow rate Q required for fitting are directly obtained from the collected data.

[0055] S3. The HQ characteristic curve and the NQ characteristic curve are modified according to the influence of the water supply temperature and frequency so that the fitting curve can be applied to any water supply temperature or any frequency.

[0056] The factors affecting the characteristic curve of the water ring network circulating water pump include speed n, water supply temperature t G , impeller diameter D and pipe network pressure;

[0057] The circulating water pump of the water ring network and the air conditioning system are fixed, so the impeller diameter and the network pressure remain unchanged; the water supply temperature t G The density and viscosity of water are affected, which changes the pump characteristic curve. It can be seen that the main factors affecting the characteristic curve of the water ring network circulating water pump are the speed n and the water supply temperature t G .

[0058] 1) Speed ​​n of circulating water pump in water ring network

[0059] The pump flow rate Q, head H, and shaft power N are all related to the speed n. Combined with the similarity law of the circulating water pump in the water ring network, the following relationship is obtained:

[0060]

[0061] Wherein, f is the frequency of the circulating water pump in the water ring network, and the subscripts 1 and 2 represent different operating conditions.

[0062] Since the speed of the circulating water pump in the water ring network is directly proportional to the frequency, if the flow rate Q, head H, and shaft power N of the water pump at a certain frequency are known, the flow rate Q, head H, and shaft power N at any frequency can be obtained. Similarly, if the water pump characteristic curve at a certain frequency is fitted, the water pump characteristic curves at other frequencies can also be obtained.

[0063] 2) Water supply temperature t G

[0064] The water supply temperature t G The density and viscosity of water are affected. The head H and flow rate Q of the water ring network circulating water pump have nothing to do with the density, and the shaft power N increases with the increase of density. Therefore, the influencing factors of the HQ characteristic curve of the water ring network circulating water pump are the speed n, and the influencing factors of the NQ characteristic curve are the speed n and the water supply temperature t G .

[0065] S4. Using the modified HQ characteristic curve and NQ characteristic curve as a water flow monitoring model, and using the water flow monitoring model to monitor the water flow of the water ring water supply pipeline.

[0066] In addition, variable operating condition tests can be carried out, and a variety of different test conditions covering various water supply temperatures and frequencies can be designed. The water flow monitoring model can be used for online flow identification, and the identification results can be compared and analyzed. The effects of HQ and NQ characteristic curve flow identification can be compared and compared with the measured values ​​for error analysis, so that the results obtained by the water flow monitoring model are more accurate.

[0067] In one embodiment, Figure 3 As shown, multiple subsystems include a closed cooling tower, a distributed water source heat pump system for office tower 1, a buried pipe heat exchange system, a data center waste heat recovery system, a gas boiler, a water source heat pump system for part of the podium, a distributed water source heat pump system for office tower 2, and a multi-effect full-process water treatment device;

[0068] The closed cooling tower, the distributed water source heat pump system of office tower one, the buried pipe heat exchange system, the data room waste heat recovery system, the gas boiler, the podium water source heat pump system, and the distributed water source heat pump system of office tower two are all connected to the energy management system, and are connected to the water ring network circulating water pump through a first pipeline and to the multi-effect full-process water treatment device through a second pipeline. The first pipeline and the second pipeline together form the water ring water supply pipeline. The multi-effect full-process water treatment device is connected to the water ring network circulating water pump, and the water ring network circulating water pump is connected to the energy management system.

[0069] Energy meters are installed between the closed cooling tower, the distributed water source heat pump system of office tower one, the buried pipe heat exchange system, the data room waste heat recovery system, the gas boiler, the water source heat pump system of the podium, the distributed water source heat pump system of office tower two and the second pipeline; all energy meters are connected to the energy management system.

[0070] There are two gas boilers, both of which are connected to the energy management system, and are respectively equipped with their own energy meters.

[0071] In the air conditioning system of the present invention, the entire water loop system is connected to a water source multi-split unit, a buried pipe heat exchange system, a data room waste heat recovery system (magnetic suspension chiller condenser side), a gas boiler, and a closed cooling tower. The water temperature of the circulating water loop fluctuates within the range of 5 to 37°C. When it exceeds 37°C, the cooling tower is turned on, and when it is lower than 5°C, the gas boiler is put into use. The buried pipe heat exchange system can take out cold in summer and not only take out heat in winter, but also store heat.

[0072] The air-conditioning system of the present invention is based on multi-energy complementarity, source-load interaction, and network-storage interaction. In addition to solving the simultaneous cooling and heating load demands of the building, it can also make full use of the waste heat inside the building (such as waste heat from the data center) without causing energy waste. The air-conditioning system has high overall energy efficiency and can greatly save the later operating costs of this type of building.

[0073] The present invention uses the characteristic curve of the water ring network circulating water pump as a water flow monitoring model to measure the water flow of the air-conditioning system. It is fast, effective, and low-cost. The flow value can be obtained while the system is running. It does not require the installation of other instruments. It only requires the existing pressure difference sensor and temperature sensor of the system, and has little impact on the pipeline. According to the solution of the flow rate by the HQ and NQ characteristic curves, the accuracy of identification through the HQ characteristic curve is high and the error range is stable. In the method of identifying the flow rate by the NQ characteristic curve, the power value is easy to obtain, and the error is low during high-frequency operation. The indirect identification of flow and heat based on pressure difference breaks the limitations of the existing energy consumption monitoring platform, and can also play an important role in variable flow energy-saving technology. It has certain practicality and has broad prospects in the use of various water pumps and other power components.

[0074] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0075] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multi-energy complementary source-grid-load-storage-control integrated green low-carbon air conditioning system, characterized in that: It includes a water ring network circulating water pump and multiple subsystems, wherein the water ring network circulating water pump connects multiple subsystems to form a water ring water supply pipeline, and the water ring water supply pipeline is provided with a temperature sensor and a pressure difference sensor for collecting water supply temperature and pressure difference; The water ring water supply pipeline adopts a preset flow monitoring method to monitor the water flow of the water ring water supply pipeline. The preset flow monitoring method includes: S1. Adjust the operating frequency of the water circulation pump of the water ring network to a set frequency, and collect the pressure difference and water supply temperature data when the air conditioning system is running; S2. Fit the collected data using the least square method to obtain the HQ characteristic curve and the NQ characteristic curve respectively; S3, modifying the HQ characteristic curve and the NQ characteristic curve according to the influence of the water supply temperature and frequency, so that the fitting curve can be applied to any water supply temperature or any frequency; S4. Using the modified HQ characteristic curve and NQ characteristic curve as a water flow monitoring model, and using the water flow monitoring model to monitor the water flow of the water ring water supply pipeline.

2. The multi-energy complementary source-grid-load-storage-control integrated green low-carbon air-conditioning system according to claim 1 is characterized in that: The step S2 specifically includes: The flow measurement function relationship based on the air conditioning system and the water ring network circulating water pump is: Q=f(ρg,H,N,D,n) Among them, Q is the flow rate of the water ring network circulating water pump delivered to the pipeline, m 3 / h; ρ is the density of the transported liquid kg / m 3 ; g is the acceleration of free fall, m / s 2 ; H is the head of the water ring network circulating water pump, m, which can be obtained by measuring the pressure difference; N is the shaft power of the water ring network circulating water pump, kW; D is the impeller diameter, the water ring network circulating water pump is fixed, and the impeller diameter will not change; n is the speed, r / min; The performance curves of the water ring network circulating water pump include the HQ curve and the NQ curve. The performance curves of the centrifugal water pump with backward impeller are obtained by experimental measurement at a fixed speed with clean water of a set temperature under normal pressure. Among them, for the HQ curve, the flow rate increases and the head continues to decrease; for the NQ curve, the flow rate increases, and the shaft power first increases and then tends to remain unchanged. According to the trends of HQ curve and NQ curve, the HQ curve of the circulating water pump of the water ring network is fitted with the quadratic curve of the least squares method, that is: H=α0+α1Q+α2Q 2 The NQ curve is fitted with a cubic curve using the least squares method, namely: N=β0+β1Q+β2Q 2 +β3Q 3 Among them, α0 and β0 are fitting constants; α1, α2, β1, β2, and β3 are fitting coefficients; The HQ curve and NQ curve are obtained through the above fitting process, which can realize the identification of the flow rate Q of the water ring water supply pipeline.

3. The multi-energy complementary source-grid-load-storage-control integrated green low-carbon air-conditioning system according to claim 1 is characterized in that: In step S3, the factors affecting the characteristic curve of the water ring network circulating water pump include the speed n, the water supply temperature t G , impeller diameter D and pipe network pressure; The pump flow rate Q, head H, and shaft power N are all related to the speed n, and the following relationship is obtained: Wherein, f is the frequency of the circulating water pump in the water ring network, and the subscripts 1 and 2 represent different operating conditions. Since the speed of the circulating water pump in the water ring network is directly proportional to the frequency, if the flow rate Q, head H, and shaft power N of the water pump at a certain frequency are known, the flow rate Q, head H, and shaft power N at any frequency can be obtained. Similarly, if the water pump characteristic curve at a certain frequency is fitted, the water pump characteristic curves at other frequencies can also be obtained.

4. The multi-energy complementary source-grid-load-storage-control integrated green low-carbon air-conditioning system according to claim 3 is characterized in that: The water supply temperature t G The factors that affect the density and viscosity of water are the head H and flow rate Q of the water ring network circulating water pump and the density. The shaft power N increases with the increase of density. The factors affecting the HQ characteristic curve of the water ring network circulating water pump are the speed n, and the factors affecting the NQ characteristic curve are the speed n and the water supply temperature t. G .

5. The multi-energy complementary source-grid-load-storage-control integrated green low-carbon air-conditioning system according to claim 1 is characterized in that: Multiple subsystems include closed cooling tower, distributed water source heat pump system for office tower 1, underground pipe heat exchange system, data center waste heat recovery system, gas boiler, water source heat pump system for part of the podium, distributed water source heat pump system for office tower 2, and multi-effect full-process water treatment device; The closed cooling tower, the distributed water source heat pump system of office tower one, the buried pipe heat exchange system, the data room waste heat recovery system, the gas boiler, the podium water source heat pump system, and the distributed water source heat pump system of office tower two are all connected to the energy management system, and are connected to the water ring network circulating water pump through a first pipeline and to the multi-effect full-process water treatment device through a second pipeline. The first pipeline and the second pipeline together form the water ring water supply pipeline. The multi-effect full-process water treatment device is connected to the water ring network circulating water pump, and the water ring network circulating water pump is connected to the energy management system.

6. The multi-energy complementary source-grid-load-storage-control integrated green low-carbon air-conditioning system according to claim 5 is characterized in that: Energy meters are installed between the closed cooling tower, the distributed water source heat pump system of office tower one, the buried pipe heat exchange system, the data room waste heat recovery system, the gas boiler, the water source heat pump system of the podium, the distributed water source heat pump system of office tower two and the second pipeline; all energy meters are connected to the energy management system.

7. The multi-energy complementary source-grid-load-storage-control integrated green low-carbon air conditioning system according to claim 5 is characterized in that: There are two gas boilers, both of which are connected to the energy management system, and are respectively equipped with their own energy meters.

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