燃煤热电联产区域供热系统热源优化配置研究

发布时间：2019-06-26 20:57

【摘要】：近年来，区域供热系统在我国供热系统中所占的比例逐步提高，，同时热电联产机组作为一种主要的热源形式在区域供热系统中的应用越来越广泛。机组设备的类型、容量和性能都在变化，但对热电联产区域供热系统热源的优化配置、规划设计研究存在一定的滞后，特别是热电联产区域供热系统的热化系数，未能随着热电联产机组的性能变化从理论上给出确定方法。本文针对燃煤热电联产区域供热系统，通过节能性和经济性分析，对热电联产区域供热系统的最佳热化系数与热源优化配置进行了研究。首先，论文分析比较了国内外常用的热电联产系统能耗评价指标，其中一次能源相对节约率和不可逆损失相对减少率这两个指标更适于表示热电联产系统相对于热电分产系统的节能效果，建议引入到我国热电联产系统评价指标体系中，并建立了热电联产区域供热系统热源的一次能源相对节约率和不可逆损失相对减少率计算数学模型。第二，建立了凝汽供暖两用型和背压式热电联产机组的热力系统模型。针对不同型号的机组，确定了热电联产机组总能耗、发电功率与机组供热能力之间的关系。对于凝汽供暖两用型机组，采用正交试验设计方法对影响热电联产机组综 4个主要参数进行了因素分析。结果表明：对综合热效率影响最大的因素是汽轮机进汽量和供热抽汽量，而对最大的是供热抽汽压力。分别以一次能源相对节约率和不可逆损失相对减少率作为评价指标，对凝汽供暖两用型机组的热力特性进行分析，提出了节能最小抽汽比的概念。对于NC145、NC200和NC300机组，基于一次能源相对节约率和不可逆损失相对减少率的节能最小抽汽比在0.14~0.2之间。第三，基于一次能源相对节约率，建立了热电联产区域供热系统节能性热化系数优化数学模型。对于凝汽供暖两用型机组，供暖气象参数和区域锅炉热效率对最佳热化系数的影响较大。以2台NC300为基本热源时，寒冷A区的节能性最佳热化系数取值范围为0.57~0.7，寒冷B区为0.66~0.73；严寒A区为0.53~0.62，严寒B区为0.55~0.65，严寒C区为0.57~0.65。区域锅炉热效率对最佳热化系数的影响有限，以区域锅炉平均热效率70%时最佳热化系数作为最终结果是可以接受的。对于背压式机组，机组型号对最佳热化系数影响不大，气象参数的影响也不如对凝汽供暖两用型机组那么明显。仅有供暖热负荷时，机组台数对热化系数的影响较大，机组台数从2台增加到4台，最佳热化系数也逐渐增大，从0.74~0.89变为0.84~0.94。对于B80机组，考虑了常年性热负荷之后，寒冷地区的最佳热化系数在[0.6,0.7]之间，且与供暖室外计算温度高度相关，常年性热负荷比越大，最佳热化系数越大。严寒地区的最佳热化系数在[0.5,0.65]之间，与供暖室外计算温度及常年性热负荷比相关性小。第四，建立了热电联产区域供热系统经济性热化系数优化数学模型。热电联产机组供热成本分摊比是确定热电联产系统供热成本的关键因素。在已有的分摊方法基础上，本文提出了改进的热电联合法，并以该方法作为供热成本分摊的依据。常见的热电联产区域供热系统热源中，供热固定成本最高的是凝汽供暖两用型机组，最低的是燃煤锅炉；而可变成本最高的是燃煤锅炉，最低的是背压式机组。从经济性角度来看，大容量凝汽供暖两用型机组的经济性优于小容量机组，而小容量背压式机组的经济性却好于大容量背压式机组。总体而言，背压式机组的经济性要优于凝汽供暖两用型机组。NC300和B80机组的经济性最佳热化系数的变化范围分别为0.65~0.86和0.57~0.8。最后，应用上述研究成果，针对一实际热电联产区域供热项目，对供热系统能耗现状进行评价，同时对供热系统远期规划的热源配置进行了优化。
[Abstract]:In recent years, the proportion of the regional heating system in the heating system of our country has been gradually increased, and the application of the cogeneration unit as a main heat source in the regional heating system is becoming more and more extensive. The type, the capacity and the performance of the unit equipment are changing, but the optimization of the heat source of the heat supply system in the cogeneration area has a certain lag, in particular the thermalization coefficient of the heat supply system in the cogeneration area, The method of determining the performance of the cogeneration unit has not been given theoretically. Based on the energy-saving and economic analysis of the heat-supply system of the coal-fired cogeneration zone, the optimal heat-heating coefficient and the optimal configuration of the heat-source are studied by the energy-saving and economic analysis. First, the paper analyzes the energy consumption evaluation index of the cogeneration system, which is commonly used at home and abroad, among which, the two indexes of the relative reduction rate and the irreversible loss of the energy-saving energy are more suitable to represent the energy-saving effect of the cogeneration system with respect to the thermoelectric power distribution system. The results and suggestions are introduced in the evaluation index system of the cogeneration system of our country, and the mathematical model of the relative reduction rate and the relative reduction rate of the non-reversible loss of the heat source of the heat source of the heat supply system in the cogeneration area is established. Type II. The thermal system of the condensing and steam heating type and back pressure type cogeneration unit is established. Series model. For units of different models, the total energy consumption of the cogeneration unit, the power generation power and the heating capacity of the unit are determined. For condensing steam heating type units, the orthogonal test design method is adopted to influence the heat and power of the heat and power plant. The main parameters of the overall 4 main parameters of the production unit The results show that the most important factors to the integrated thermal efficiency are the steam inlet and the steam extraction, and the maximum is for the supply of steam. In this paper, the thermal characteristics of the condensing steam heating unit are analyzed by using the relative reduction of the relative saving rate and the irreversible loss of the condensing energy as the evaluation index, and the energy-saving minimum extraction is put forward. The concept of steam-to-gas ratio. For NC145, NC200 and NC300 units, the energy-saving minimum extraction ratio based on the relative reduction of the energy-saving rate and the irreversible loss of the primary energy is 0.14 ~ "0.2. Third, based on the relative saving rate of energy-saving energy, the energy-saving and thermalization system of the heat supply system of the cogeneration zone is established." The mathematical model of the number is optimized. The thermal efficiency of the heating and meteorological parameters and the thermal efficiency of the regional boiler is the best for the condensing and heating type units. When two NC300 is the basic heat source, the optimum temperature-saving coefficient of the cold-A zone is 0.57-0.7, the cold-B area is 0.66-0.73, the cold-A zone is 0.53-0.62, the cold-B area is 0.55-0.65, and the cold-C area is 0. 57-0.65. The effect of the thermal efficiency of the regional boiler on the optimal thermalization coefficient is limited, and the optimal thermalization coefficient is the most end when the average thermal efficiency of the regional boiler is 70%. The fruit is acceptable. For the back pressure type unit, the model of the unit has little influence on the optimal thermalization coefficient, and the influence of the meteorological parameters is not as good as the steam heating and heating. In the case of heat load only, the number of units has a large influence on the thermalization coefficient, the number of units increases from 2 to 4, and the optimum thermalization coefficient is gradually increased, from 0.74 to 0.89 to 0. 84-0.94. For B80 units, after the normal annual thermal load is considered, the optimal thermalization coefficient in the cold area is between[0.6, 0.7] and is highly correlated with the heating outdoor calculation temperature. The higher the normal annual thermal load ratio, the more The greater the thermal coefficient, the greater the optimum thermalization coefficient in the severe cold area. Fourth, the economic heat of the heat supply system of the cogeneration zone is established. The mathematical model of the optimization of the heat supply cost of the cogeneration unit. The ratio of the heat supply cost of the cogeneration unit is to determine the cogeneration system. The key factors of the cost of heat supply are as follows: on the basis of the existing apportionment method, the improved thermoelectric combination method is put forward, and the method is used as the basis of this method. according to the heat supply cost sharing basis, in the common heat supply system heat source of the cogeneration area, the heating fixed cost is the highest, the condensing steam heating type unit is the lowest, the coal-fired boiler is the lowest, and the variable cost is the highest in the coal-fired boiler, The lowest is the back pressure unit. From the economical point of view, the economy of the high-capacity condensing steam heating unit is better than that of the small-capacity unit, while the economy of the small-capacity back-pressure unit is good. In general, the economy of the back pressure unit is superior to that of the high-capacity back-pressure unit. The variation range of the optimal heat-heating coefficient of the NC300 and B80 units is 0.65-0.86, respectively. and finally, applying the research results, evaluating the current situation of the energy consumption of the heat supply system according to the heat supply project of an actual cogeneration area, and simultaneously,
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU995

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