CN-122019935-A - Boiler condenser thermal efficiency measuring and calculating method and system based on condensation rate calculation

CN122019935ACN 122019935 ACN122019935 ACN 122019935ACN-122019935-A

Abstract

The invention discloses a boiler condenser thermal efficiency measuring and calculating method and system based on condensation rate calculation, and belongs to the field of boiler energy efficiency testing. The method comprises the steps of obtaining first flue gas temperature and first relative humidity at an inlet of a condenser and second flue gas temperature and second relative humidity at an outlet of the condenser, determining a water vapor condensation rate when flue gas passes through the condenser, obtaining fuel characteristic parameters at least comprising fuel low-level heating value and water vapor amount generated by burning hydrogen in the fuel, and calculating the thermal efficiency of the condenser based on the water vapor condensation rate, the fuel low-level heating value and the water vapor amount. According to the invention, the heat efficiency of the condenser can be rapidly and accurately calculated by measuring the temperature and the relative humidity of the flue gas before and after the condenser and combining the fuel characteristic parameters, and complex parameters such as flue gas components, flue gas flow, cooling water flow and cooling water temperature are not required to be measured, so that the method has the advantages of less measurement parameters, simplicity in calculation, low equipment cost and capability of realizing real-time online monitoring.

Inventors

CHEN ZHIGANG
Zhao Zhenda
GAO SHUAI
ZHANG BIAO
YE XUFANG
XU CHONGTAO
LIU CHANG
CUI QI
ZHANG BAOXIANG
ZHENG GUIHONG
ZHANG XIN
LI DONGYI

Assignees

天津市特种设备监督检验技术研究院(天津市特种设备事故应急调查处理中心)

Dates

Publication Date: 20260512
Application Date: 20260415

Claims (9)

1. The method for measuring and calculating the thermal efficiency of the boiler condenser based on the condensation rate is characterized by comprising the following steps of: S1, acquiring a first flue gas temperature and a first relative humidity at an inlet of a condenser, and a second flue gas temperature and a second relative humidity at an outlet of the condenser; S2, determining a first flue gas moisture content at an inlet of a condenser based on the first flue gas temperature and the first relative humidity, determining a second flue gas moisture content at an outlet of the condenser based on the second flue gas temperature and the second relative humidity; s3, acquiring fuel characteristic parameters, wherein the fuel characteristic parameters at least comprise low-level heating value of fuel and water vapor quantity generated by hydrogen combustion in each cubic meter of fuel; and S4, calculating to obtain the heat efficiency of the condenser only according to the water vapor condensation rate, the low-level heating value of the fuel and the water vapor amount generated by hydrogen combustion.
2. The method for measuring and calculating the thermal efficiency of a boiler condenser based on the condensation rate according to claim 1, wherein in S2, the condensation rate of water vapor is calculated based on the first flue gas moisture content and the second flue gas moisture content according to the following formula: Wherein, the In order to achieve the condensation rate of the water vapor, For the first moisture content of the flue gas, Is the second flue gas moisture content.
3. The method for measuring and calculating the thermal efficiency of a boiler condenser based on the condensation rate according to claim 2, wherein the first flue gas moisture content and the second flue gas moisture content are calculated by the following formulas: Wherein, the The moisture content of the flue gas is represented, P st.Sat.ti represents the saturated pressure of the water vapor corresponding to the temperature of the flue gas, and the unit is kPa; is at atmospheric pressure and has the unit of kPa.
4. The method for measuring and calculating the thermal efficiency of the boiler condenser based on the condensation rate calculation as set forth in claim 3, wherein the water vapor saturation pressure P st.Sat.ti corresponding to the flue gas temperature is calculated by using the following fitting formula: P st.Sat.ti = 0.000789T i 3 - 0.1971T i 2 + 17.9687T i - 485.673 In the formula, P st.Sat.ti is KPa, T i is flue gas temperature, and the unit is DEG C.
5. The method for measuring and calculating the thermal efficiency of the boiler condenser based on the condensation rate calculation as set forth in claim 3, wherein the water vapor saturation pressure P st.Sat.ti corresponding to the flue gas temperature is calculated by using an antwann equation: P st.Sat.ti = 10^(A- B/(T i + C)) ; wherein, T i is the flue gas temperature, A, B, C is the preset Ituwan constant, A=7.2326, B=1795.9922, C= 244.3368.
6. The method for measuring and calculating the thermal efficiency of a boiler condenser based on the calculation of the condensation rate according to any one of claims 1 to 5, wherein the thermal efficiency of the condenser is calculated by the following formula: Wherein, the The steam amount m 3 /m 3 is the steam amount generated by burning hydrogen in each cubic meter of fuel gas; is the vaporization latent heat of water vapor in the flue gas, KJ/kg, and is obtained by looking up a table; The low-position heating value of the fuel gas is KJ/m 3 .
7. The method for measuring and calculating the thermal efficiency of a boiler condenser based on the condensation rate according to claim 6, wherein the amount of water vapor generated by hydrogen combustion per cubic meter of fuel is calculated by the following formula: Wherein, the As the volume fraction of hydrogen in the fuel, Is the volume fraction of hydrocarbons in the fuel, n is the number of hydrogen atoms in the hydrocarbons.
8. The method for measuring and calculating the thermal efficiency of a boiler condenser according to claim 6, further comprising obtaining a simple test thermal efficiency of the boiler body Calculating the heat efficiency of the whole boiler comprising the condenser according to the following formula : Wherein, the , The condensing heat efficiency of the condenser; is the heat loss rate of the smoke exhaust; fuel gas is represented by formula And (3) calculating: For the rate of heat loss from incomplete combustion of the gas, The heat dissipation loss rate is the heat dissipation loss rate; The air excess coefficient is the excess air coefficient at the smoke exhaust position, which is obtained by testing; the temperature of the discharged smoke of the condenser is in DEG C; the temperature of the cold air entering the furnace is at the temperature of DEG C, and the test results.
9. A boiler condenser thermal efficiency measurement system based on condensation rate calculation, comprising: The first temperature and humidity sensor is arranged at the inlet of the condenser and used for collecting the first flue gas temperature and the first relative humidity; the second temperature and humidity sensor is arranged at the outlet of the condenser and used for collecting the temperature and the second relative humidity of the second flue gas; The storage module is used for storing fuel characteristic parameters, wherein the fuel characteristic parameters at least comprise low-level heating value of fuel and water vapor quantity generated by hydrogen combustion in each cubic meter of fuel; The processing module is respectively connected with the first temperature and humidity sensor, the second temperature and humidity sensor and the storage module, and is used for executing the method for measuring and calculating the thermal efficiency of the boiler condenser according to any one of claims 1 to 8.

Description

Boiler condenser thermal efficiency measuring and calculating method and system based on condensation rate calculation Technical Field The invention relates to the technical field of fluid fuel boiler condensation heat efficiency calculation, in particular to a boiler condenser heat efficiency measuring and calculating method and system based on condensation rate calculation. Background In the fields of industrial production and residential life, the thermal efficiency of boilers is a key factor affecting the energy consumption level and the operating economy. Among them, the condensing boiler has been increasingly used because its thermal efficiency is significantly higher than that of the conventional boiler by recovering latent heat in flue gas. The condenser is used as a core component for realizing high-efficiency heat recovery of the condensing boiler, and the accurate measurement and calculation of the heat efficiency is an indispensable link for evaluating the heat efficiency of the whole boiler. Currently, the measurement and calculation of the heat efficiency of condensers and boilers in the industry is mainly based on the existing standard methods, such as: in the standard NB/T47066-2018 'condensing boiler thermal performance test method', a heat loss method is adopted for measurement; in the standard GB/T10180-2017 'industrial boiler thermal performance test procedure', an input-output heat method is adopted for measurement. However, these conventional standard test methods have the following significant drawbacks in practical applications: 1. The measurement parameters are various, namely, the parameters such as the temperature of the flue gas, the flow of working medium, the water temperature of an inlet and an outlet, the components of the flue gas and the like are required to be synchronously collected, and the requirements on the complexity and the equipment cost of a test system are high. 2. The calculation process is complex, relies on complex heat transfer mathematical models and complicated iterative calculation, is easy to introduce human errors, and has higher requirements on professional ability of testers. 3. The real-time performance is poor, the complete test and calculation period is long, the working condition change cannot be responded quickly, and the real-time monitoring and evaluation of the heat efficiency of the condenser and the boiler are difficult to realize. 4. The equipment and maintenance cost is high, the high-precision sensor and the complex installation and debugging are relied on, the field implementation difficulty is high, and the maintenance cost is high. Therefore, the prior art lacks a condenser thermal efficiency measuring and calculating method capable of simplifying measurement, fast calculation and real-time feedback, which becomes a technical bottleneck for restricting boiler energy efficiency fine management and timely optimization. Disclosure of Invention Therefore, the invention aims to provide a method and a system for measuring and calculating the thermal efficiency of a boiler condenser based on condensation rate calculation, which can be used for measuring and calculating the thermal efficiency of the condensing boiler on the premise of ensuring engineering application precision by obviously reducing the number of required measurement parameters and simplifying calculation flow. The method specifically comprises the following steps of: 1. The measuring and calculating efficiency is improved, the measuring and calculating of the thermal efficiency of the condenser can be completed rapidly, and the evaluation time is shortened greatly. 2. The implementation threshold is reduced, the dependence on high-precision and multi-type sensors is reduced, and the complexity and cost of test equipment are reduced. 3. The real-time performance is enhanced, so that the thermal efficiency states of the condenser and the boiler can be estimated and monitored in near real time, and the energy efficiency level can be mastered in time by operating personnel. 4. The practicability is improved, a set of test scheme which is simple and convenient to operate and reliable in result is provided, and the method is convenient to popularize and apply in the scene of on-site inspection, daily monitoring and the like. In order to achieve the above object, the method for measuring and calculating the thermal efficiency of the boiler condenser based on the condensation rate calculation of the invention comprises the following steps: S1, acquiring a first flue gas temperature and a first relative humidity at an inlet of a condenser, and a second flue gas temperature and a second relative humidity at an outlet of the condenser; S2, determining a first flue gas moisture content at an inlet of a condenser based on the first flue gas temperature and the first relative humidity, determining a second flue gas moisture content at an outlet of the condenser based on the second flue gas t