Building energy consumption system operation evaluation method considering matching

Abstract

The invention relates to a matching-considered building energy consumption system operation evaluation method, which comprises the following steps of: 1, selecting an air conditioner terminal to be analyzed and evaluated for a centralized air conditioner system in a building to be analyzed; 2, establishing an air conditioning system operation matching evaluation model and a system mismatching coefficient expression; 3, defining an operation matching degree index of the air conditioning system and constructing a matching degree expression; and 4, establishing a matching degree grading standard, and delimiting an air conditioning system terminal operation matching degree evaluation grading area. And 5, acquiring operation parameters of the air-conditioning terminal system, calculating the operation matching degree of the air-conditioning system, and comprehensively evaluating the operation performance of the air-conditioning system according to a matching degree grading standard. According to the method, the air conditioning system operation matching evaluation model is established, the interaction among the operation parameters of the air conditioning system and the influence of the operation parameters on the overall performance can be more accurately reflected, the operation matching degree index of the air conditioning system is defined, the matching degree grading standard is constructed, and the method is beneficial to diagnosing the system operation problem and providing an optimization adjustment direction.

Description

Technical Field

[0001] The present invention belongs to the technical field of building energy system operation, and in particular relates to a building energy system operation evaluation method considering matching. Background Art

[0002] In the current building environment, the energy consumption of building energy air conditioning systems, as key facilities to ensure the quality of indoor environment, is becoming increasingly prominent. According to relevant data, the energy consumed by air conditioning systems accounts for 60% of the total energy consumption of buildings, and this proportion is even higher in some large commercial complexes and office buildings. Although measures such as the use of high-efficiency refrigeration equipment, optimization of system design, and the introduction of intelligent control strategies have been taken in recent years to reduce energy consumption, energy waste is still common in actual air conditioning systems. The main problems include but are not limited to: the poor matching between system components leads to low overall efficiency; the lack of in-depth understanding of the system response characteristics under different working conditions; and the difficulty of existing evaluation methods to fully and accurately reflect the actual operating status of the system.

[0003] Therefore, it is particularly necessary to provide a building energy system operation evaluation method that takes matching into account and to develop a new method that can comprehensively consider the above factors and effectively evaluate the operation matching performance of the building air-conditioning system. Summary of the invention

[0004] In order to address the deficiencies in comprehensiveness and accuracy of existing evaluation methods for the operation of building energy systems, the present invention comprehensively considers the interactions between the operating parameters of various parts of the air-conditioning system and the actual response characteristics under different working conditions to evaluate the operating performance of the air-conditioning system. This invention aims to provide a scientific basis for improving system operating efficiency and reducing energy consumption through accurate measurement and analysis of key performance indicators. At the same time, it also lays a solid foundation for future energy-saving adaptation, optimization and transformation of system operation, and provides a building energy system operation evaluation method that takes matching into account.

[0005] In order to solve the above technical problems, the present invention includes the following technical solutions:

[0006] A building energy system operation evaluation method considering matching includes the following steps:

[0007] Step S1: for the centralized air conditioning system in the building to be analyzed, select the air conditioning terminal to be analyzed and evaluated;

[0008] Step S2, establishing an air conditioning system operation matching evaluation model and a system mismatch coefficient function expression, wherein the air conditioning system operation matching evaluation model includes the fire accumulation loss, heat transfer resistance, and the inlet and outlet temperatures of the cold and hot fluids at the air conditioning terminal involved in the operation of the air conditioning system, and establishing a correlation between the air conditioning system operation parameters. The fire accumulation loss calculation formula is:

[0009] Among them, △J loss is the fire loss, in K·kW; Q is the heat transfer of the heat exchanger, in kW; T h,in is the thermodynamic temperature of the hot fluid inlet of the heat exchange coil, in K; T h,out is the thermodynamic temperature of the hot fluid outlet of the heat exchange coil, in K; T c,in is the thermodynamic temperature of the cold fluid inlet of the heat exchange coil, in K, T c,out is the thermodynamic temperature of the cold fluid outlet of the heat exchange coil, in K;

[0010] The thermal resistance calculation formula of the heat transfer process of the hot and cold fluids in the heat exchange coil is:

[0011]

[0012] Among them, c h is the specific heat capacity of the hot fluid in the heat exchange coil, in J / (kg·K); is the mass flow rate of the heat fluid in the heat exchange coil, in kg / s; ε is the heat exchange efficiency of the air conditioner terminal coil, in dimensionless units;

[0013] Step S3: define the air conditioning system operation matching index and construct a matching function expression to define the air conditioning system operation matching index. The function expression is:

[0014]

[0015] Step S4: Establish matching degree grading standards and define matching degree evaluation grading areas for air-conditioning system terminal operation;

[0016] Step S5, obtain the operating parameters of the air conditioning terminal system, including the water side flow rate, air side flow rate, water side inlet and outlet water temperature, air side inlet and outlet air temperature, and calculate the logarithmic mean temperature difference of the heat exchange at the system terminal △T m and the product of heat transfer coefficient and area KF; calculate the operation matching degree of the air conditioning system, and evaluate the operation matching of the air conditioning system according to the matching degree classification standard;

[0017] Among them, the logarithmic mean temperature difference of the heat exchange at the end of the air conditioning system ΔT m The expression is:

[0018]

[0019] The calculation expression of the product of heat transfer coefficient and area KF is:

[0020]

[0021] Furthermore, in step S1, the centralized air-conditioning system in the building includes fan coil units, a fresh air system, and a full air system, and the air-conditioning terminal includes a fan coil unit FCU and an air handling unit AHU in the air-conditioning system.

[0022] Furthermore, in step S2, the heat exchange efficiency ε of the air conditioner terminal coil satisfies:

[0023] T h,in -T h,out =ε(T h,in -T c,in );

[0024] According to the heat transfer principle, the fluids on both sides of the heat exchange coil at the end of the air conditioning system satisfy the thermal balance equation:

[0025]

[0026] Among them, c c is the specific heat capacity of the cold fluid in the heat exchange coil, in J / (kg·K); is the mass flow rate of cold fluid in the heat exchange coil, in kg / s.

[0027] Furthermore, in step S2, according to the heat exchange efficiency formula and the heat balance formula, the following is obtained:

[0028]

[0029] Furthermore, in step S2, according to the heat transfer principle, when the heat transfer coefficient K and the heat exchange area F of the air conditioner terminal heat exchanger are known, the temperatures of the cold and hot fluids satisfy the following formula:

[0030]

[0031] Furthermore, in step S2, the thermal resistance of the heat transfer process of the hot and cold fluids in the heat exchange coil is expressed in the following form:

[0032]

[0033] Among them, R h is the thermal resistance of the heat transfer process of the hot and cold fluids in the heat exchange coil, K / W; Ψ is the mismatch coefficient; K is the heat transfer coefficient, unit is W / (m 2 ·K); F is the heat transfer area of ​​the heat exchange coil, in m 2 , the mismatch coefficient Ψ expression is:

[0034]

[0035] Among them, μ is expressed as:

[0036]

[0037] Furthermore, in step S4, according to the heat exchange and inlet and outlet water temperatures of the air-conditioning terminal under different air volume gears and different inlet water flow conditions, the operation matching degree of the air-conditioning system terminal corresponding to the air volume gear and the inlet water flow conditions is calculated, and the matching degree determined by the high-end air volume, rated water volume, and relative water volume of 1 is used as the first dividing line; the matching degree determined by the high-end air volume and relative water volume of 1.5 is used as the second dividing line; the matching degree determined by the low-end air volume, 50% of the high-end air volume, and the relative water volume of 1.5 is used as the third dividing line, and a matching degree grading standard is established accordingly, and the matching degree 1 and the first dividing line, and the matching degree φ is 0.89 constitute the first area; the first dividing line and the second dividing line, the matching degree The second dividing line and the third dividing line have a matching degree of 0.82, forming the second area. The third area is 0.78, which constitutes the third area; the third dividing line and the matching degree 0 constitute the fourth area; the terminal operation matching evaluation grading area of ​​the air conditioning system is: excellent: the first area is Good: Zone II General: Region III Difference: Region IV

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] 1. The present invention provides a building energy system operation evaluation method that takes matching into consideration. By selecting a specific air-conditioning terminal as the analysis object and establishing a detailed operation matching evaluation model and a mismatch coefficient function expression, it can more accurately reflect the interaction between the various operating parameters of the air-conditioning system and their impact on the overall performance.

[0040] 2. The building energy system operation evaluation method considering matching proposed in this invention defines the matching index of air conditioning system operation and constructs the corresponding matching function expression, making the evaluation results more intuitive, easy to understand and compare. The quantitative evaluation index helps to quickly locate the problem and provide a clear direction for subsequent improvements.

[0041] 3. The building energy system operation evaluation method considering matching proposed in the present invention establishes a matching degree grading standard and divides the evaluation areas into different levels, which not only helps to distinguish the pros and cons of the system, but also guides users or managers to take appropriate measures for optimization and adjustment according to specific circumstances.

[0042] 4. The building energy system operation evaluation method considering matching proposed in the present invention can timely discover and solve the existing mismatch problems through accurate evaluation of the operation matching of the air-conditioning system, thereby significantly improving the energy utilization efficiency of the system and reducing unnecessary energy waste, thereby achieving the purpose of energy conservation and emission reduction, and effectively reducing the operating costs of buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A flowchart of a building energy system operation evaluation method considering matching according to an embodiment of the present invention;

[0044] Figure 2 The relationship between the relative heat exchange and the relative water volume at different air volumes at the air-conditioning terminal in a building energy system operation evaluation method considering matching in one embodiment of the present invention;

[0045] Figure 3 The matching degree classification standard and regional boundaries of the air conditioning system in the building energy system operation evaluation method considering matching according to an embodiment of the present invention;

[0046] Figure 4 The present invention provides an example of the matching performance evaluation of the operating conditions of an air-conditioning system in a building energy system operation evaluation method taking matching into account in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following is a further detailed description of the building energy system operation evaluation method considering matching provided by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description.

[0048] Embodiment 1

[0049] Combine the following Figures 1 to 4 , the building energy system operation evaluation method considering matching of the present invention is described in detail.

[0050] The building energy system operation evaluation method considering matching, such as Figure 1 As shown, the method mainly comprises the following steps:

[0051] Step S1: For the centralized air-conditioning system in the building to be analyzed, select the air-conditioning terminal to be analyzed and evaluated.

[0052] In step S1, the centralized air-conditioning system in the building mainly refers to the fan coil unit + fresh air system and the full air system, and the air-conditioning terminal mainly refers to the fan coil unit FCU and the air handling unit AHU in the air-conditioning system.

[0053] Step S2: Establish an air conditioning system operation matching evaluation model and a system mismatch coefficient function expression.

[0054] In step S2, the air conditioning system operation matching evaluation model includes the correlation between the air conditioning system operation parameters involved in the air conditioning system operation process based on the fire accumulation loss, heat transfer resistance, and the inlet and outlet temperatures of the cold and hot fluids at the air conditioning terminal. For the air conditioning system terminal, the two sides of the terminal heat exchange coil are water and air respectively. During the heat exchange process of the fluids on both sides of the coil, the fire accumulation loss can be expressed as:

[0055]

[0056] Among them, △J loss is the fire loss, in K·kW; Q is the heat transfer of the heat exchanger, in kW; T h,in , T h,out is the thermodynamic temperature of the heat fluid inlet and outlet of the heat exchange coil, in K; T c,in , T c,out are the inlet and outlet thermodynamic temperatures of the cold fluid in the heat exchange coil, respectively, in K.

[0057] In step S2, the thermal resistance of the heat transfer process of the hot and cold fluids in the heat exchange coil can be expressed as:

[0058]

[0059]

[0060] Among them, c h is the specific heat capacity of the hot fluid in the heat exchange coil, in J / (kg·K); is the mass flow rate of the heat fluid in the heat exchange coil, in kg / s; ε is the heat exchange efficiency of the air conditioner terminal coil.

[0061] In step S2, the heat exchange efficiency ε of the air conditioner terminal coil satisfies:

[0062] T h,in -T h,out =ε(T h,in -T c,in )

[0063] In step S2, according to the heat transfer principle, the fluids on both sides of the heat exchange coil at the end of the air conditioning system satisfy the thermal balance equation:

[0064]

[0065] Among them, c c is the specific heat capacity of the cold fluid in the heat exchange coil, in J / (kg·K); is the mass flow rate of cold fluid in the heat exchange coil, in kg / s;

[0066] In step S2, according to the heat exchange efficiency formula and the heat balance formula, the following is obtained:

[0067]

[0068] In step S2, according to the heat transfer principle, when the heat transfer coefficient K and the heat exchange area F of the air conditioner terminal heat exchanger are known, the temperatures of the cold and hot fluids satisfy the following formula:

[0069]

[0070] In step S2, the thermal resistance of the heat transfer process of the hot and cold fluids in the heat exchange coil can be expressed in the following form:

[0071]

[0072] Among them, R h is the thermal resistance of the heat transfer process of the hot and cold fluids in the heat exchange coil, in K / W; Ψ is the mismatch coefficient; K is the heat transfer coefficient, in W / (m 2 ·K); F is the heat transfer area of ​​the heat exchange coil, in m 2 .

[0073] In step S2, the mismatch coefficient Ψ is expressed as:

[0074]

[0075] Among them, μ is expressed as:

[0076]

[0077] Step S3: define the air conditioning system operation matching index and construct a matching function expression.

[0078] In step S3, the air conditioning system operation matching degree is defined The function expression is:

[0079]

[0080] Step S4: Establish a matching degree grading standard and define a matching degree evaluation grading area for the terminal operation of the air-conditioning system.

[0081] In the step S4, the operation matching degree of the air conditioning system terminal corresponding to the air volume gear and the water inlet flow rate is calculated according to the heat exchange and the inlet and outlet water temperatures of the air conditioning terminal under different air volume gears and different water inlet flow rates. The matching degree determined by the high-end air volume and the rated water volume (relative water volume is 1) is the first dividing line; the matching degree determined by the high-end air volume and the relative water volume of 1.5 is the second dividing line; the matching degree determined by the low-end air volume (50% of the high-end air volume) and the relative water volume of 1.5 is the third dividing line. Based on this, a matching degree grading standard is established, with the matching degree 1 and the first dividing line (matching degree is 0.89) constitutes the first area; the first dividing line and the second dividing line (matching degree is 0.82) constitutes the second area; the second dividing line and the third dividing line (matching degree The third dividing line and the matching degree 0 constitute the third area. The air conditioning system terminal operation matching evaluation grading area is: Excellent: First area Good: Zone II General: Region III Poor: Region IV

[0082] Step S5, obtain the operating parameters of the air conditioning terminal system, including the water side flow rate, air side flow rate, water side inlet and outlet water temperature, and air side inlet and outlet air temperature. Calculate the mean temperature difference of heat exchange logarithm of the system terminal △T m And the product of heat transfer coefficient and area KF. Calculate the operation matching degree of the air conditioning system, and conduct a comprehensive evaluation of the operation performance of the air conditioning system according to the matching degree classification standard.

[0083] In step S5, the logarithmic mean temperature difference of the heat exchange at the end of the air conditioning system ΔT m The expression is as follows:

[0084]

[0085] The calculation expression of the product of the heat transfer coefficient and the area KF is as follows:

[0086]

[0087] Further, according to the matching degree in step S3 The function expression of is used to calculate the operation matching degree of the air-conditioning system, and the operation performance of the air-conditioning system is comprehensively evaluated according to the matching degree grading standard described in step S4.

[0088] The effects of the present invention are further described below in conjunction with specific embodiments.

[0089] Embodiment 1

[0090] refer to Figure 1 , the operating performance of the building air conditioning system is evaluated based on the matching and sensitivity coupling analysis. According to the steps S1 to S5, the matching degree of the air conditioning terminal operating parameters can be evaluated. Table 1 shows the parameters of the water side and the wind side of a series of different models of fan coil units designed by a manufacturer under rated conditions and the matching degree of the system under rated conditions.

[0091] Table 1 Matching degree of rated working condition of air conditioner terminal

[0092] Unit Model <![CDATA[Rated air volume (m 3 / h)]]> Rated water volume (L / s) Rated cooling capacity (kW) Mismatch coefficient Match 02 350 0.104 2.13 1.11 0.90 03 520 0.158 3.26 1.12 0.89 04 680 0.201 4.17 1.12 0.89 06 1020 0.283 5.81 1.10 0.91 08 1360 0.386 7.92 1.11 0.90 10 1710 0.44 9.07 1.08 0.93 12 2040 0.54 11.12 1.08 0.93 14 2380 0.627 12.94 1.08 0.93

[0093] For the 03 model fan coil terminal in Table 1, the heat exchange curves under different air volumes and water volumes are as follows: Figure 2 As shown. Figure 2 According to step S4, the operation matching evaluation classification area of ​​the air conditioning system terminal operation matching degree is delineated as follows: Figure 3 The air conditioning system terminal operation matching evaluation grading area is: Excellent: Area I Good: Zone II General: Region III Poor: Region IV

[0094] Figure 4 As an application example of the method steps according to the present invention, the matching degree corresponding to the operating point A (high-end air volume / relative water volume 0.8) is 0.92, which belongs to the excellent matching performance area; the matching degree corresponding to the operating point B (mid-range air volume / relative water volume 0.9) is 0.88, which belongs to the good matching performance area; the matching degree corresponding to C (low-end air volume / relative water volume 1.3) is 0.8, which belongs to the general matching performance area.

[0095] The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. The above embodiments only express several embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A building energy system operation evaluation method considering matching, characterized in that: The steps include: Step S1: for the centralized air conditioning system in the building to be analyzed, select the air conditioning terminal to be analyzed and evaluated; Step S2, establishing an air conditioning system operation matching evaluation model and a system mismatch coefficient function expression, wherein the air conditioning system operation matching evaluation model includes the fire accumulation loss, heat transfer resistance, and the inlet and outlet temperatures of the cold and hot fluids at the air conditioning terminal involved in the operation of the air conditioning system, and establishing a correlation between the air conditioning system operation parameters. The fire accumulation loss calculation formula is: Among them, △J loss is the fire loss, in K·kW; Q is the heat transfer of the heat exchanger, in kW; T h,in is the thermodynamic temperature of the hot fluid inlet of the heat exchange coil, in K; T h,out is the thermodynamic temperature of the hot fluid outlet of the heat exchange coil, in K; T c,in is the thermodynamic temperature of the cold fluid inlet of the heat exchange coil, in K; T c,out is the thermodynamic temperature of the cold fluid outlet of the heat exchange coil, in K; The thermal resistance calculation formula of the heat transfer process of the hot and cold fluids in the heat exchange coil is: Among them, c h is the specific heat capacity of the hot fluid in the heat exchange coil, in J / (kg·K); is the mass flow rate of the heat fluid in the heat exchange coil, in kg / s; ε is the heat exchange efficiency of the air conditioning terminal coil, dimensionless; The mismatch coefficient function Ψ is expressed as: Among them, μ is expressed as: Step S3: define the air conditioning system operation matching index and construct a matching function expression to define the air conditioning system operation matching index. The function expression is: Step S4: Establish matching degree grading standards and define matching degree evaluation grading areas for air-conditioning system terminal operation; Step S5, obtain the operating parameters of the air conditioning terminal system, including the water side flow rate, air side flow rate, water side inlet and outlet water temperature, air side inlet and outlet air temperature, and calculate the logarithmic mean temperature difference of the heat exchange at the system terminal △T m and the product of heat transfer coefficient and area KF; calculate the operation matching degree of the air conditioning system, and conduct a comprehensive evaluation of the operation matching of the air conditioning system according to the matching degree classification standard; Among them, the logarithmic mean temperature difference of the heat exchange at the end of the air conditioning system ΔT m The expression is: The calculation expression of the product of heat transfer coefficient and area KF is:

2. The method according to claim 1, characterized in that In step S1, the centralized air-conditioning system in the building includes a fan coil unit, a fresh air system, and a full air system, and the air-conditioning terminal includes a fan coil unit FCU and an air handling unit AHU in the air-conditioning system.

3. The method according to claim 1, characterized in that In step S2, the heat exchange efficiency ε of the air conditioner terminal coil satisfies: T h,in -T h,out =ε(T h,in -T c,in ); According to the heat transfer principle, the fluids on both sides of the heat exchange coil at the end of the air conditioning system satisfy the thermal balance equation: Among them, c c is the specific heat capacity of the cold fluid in the heat exchange coil, in J / (kg·K); is the mass flow rate of cold fluid in the heat exchange coil, in kg / s.

4. The method according to claim 3, characterized in that In step S2, according to the heat exchange efficiency formula and the heat balance formula, the following is obtained:

5. The method according to claim 4, characterized in that In step S2, according to the heat transfer principle, when the heat transfer coefficient K and the heat exchange area F of the air conditioner terminal heat exchanger are known, the temperatures of the cold and hot fluids satisfy the following formula:

6. The method according to claim 5, characterized in that In step S2, the thermal resistance of the heat transfer process of the hot and cold fluids in the heat exchange coil is expressed in the following form: Among them, R h is the thermal resistance of the heat transfer process of the hot and cold fluids in the heat exchange coil, in K / W; Ψ is the mismatch coefficient; K is the heat transfer coefficient, in W / (m 2 ·K); F is the heat transfer area of ​​the heat exchange coil, in m 2 .

7. The method according to claim 1, characterized in that In the step S4, according to the heat exchange and inlet and outlet water temperatures of the air-conditioning terminal under different air volume gears and different inlet water flow conditions, the operation matching degree of the air-conditioning system terminal corresponding to the air volume gear and the inlet water flow condition is calculated, and the matching degree determined by the high-end air volume, rated water volume, and relative water volume of 1 is used as the first dividing line; the matching degree determined by the high-end air volume and relative water volume of 1.5 is used as the second dividing line; the matching degree determined by the low-end air volume, 50% of the high-end air volume, and the relative water volume of 1.5 is used as the third dividing line, and a matching degree grading standard is established accordingly, with the matching degree 1 and the first dividing line, the matching degree The first area is 0.89; the first dividing line and the second dividing line have a matching degree It is 0.82, constituting the second region; The second dividing line and the third dividing line, the matching degree The third area is 0.78, which constitutes the third area; the third dividing line and the matching degree 0 constitute the fourth area; the terminal operation matching evaluation grading area of ​​the air conditioning system is: excellent: the first area is Good: Zone II General: Region III Difference: Region IV 8. The method according to claim 1, characterized in that In step S3, according to the matching degree in step S3, The air conditioning system operation matching degree is calculated by the function expression of , and the air conditioning system operation matching degree is evaluated according to the matching degree grading standard described in step S4.

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