电厂循环水水源热泵供热系统的热经济性研究

为研究电厂循环水水源热泵供热系统的热经济性,建立了热泵供热系统计算模型,对循环水水源热泵供热与抽汽供热两种方式进行了热经济性比较,引入单位供热负荷功耗差指标定量表征热泵供热的热经济性,提出了采用循环水水源热泵进行供热的可行性判据。对某200 MW典型机组进行了计算,发现供热温度越低、供热负荷越小、供热抽汽压力越大、制热循环效率越高,电厂采用循环水水源热泵供热的可行性越好。     

对沈阳市供热企业资质审查引发的分析与思考

介绍了沈阳市的供热现状、特点和近几年在供热方面取得的成绩,同时围绕供热企业资质审查工作对供热的市场化运作、供热立法、供热企业的准入、退出与管理及未来的发展方向进行了分析和探讨,对供热体制的改革提供了一些思路。     

220MW汽轮机组供热改造研究与应用

为响应国家节能减排相关政策,同时适应胜利油田发展需要,胜利发电厂一期2台220 MW纯凝汽机组进行了热电联产供热改造。本文对供热改造方案进行了介绍,并对本体改造的安全性进行了分析。通过对机组供热改造后采集的供热运行参数、经济数据进行了对比分析,论证了供热改造的意义及必要性,对同类型机组供热改造有借鉴意义。     

供热能耗与供热锅炉的空气过量系数关系

通过理论计算和实际测试,对供热锅炉的空气过量系数导致供热能耗增加进行了分析、论证,得出了供热锅炉在实际运行中的空气过量系数增加是导致供热能耗上升的结论,并对供热锅炉的空气过量系数增大原因进行分析。     

利用吸收式循环对热电机组供热首站改造的经济性分析

利用吸收式换热原理对郑州市某热电厂进行集中供热系统热网首站进行改造,依次进行方案设计,供热机组最小抽汽量优化,经济、环境效益分析计算。研究结果表明,利用吸收式换热机组对郑州市某热电厂进行供热首站改造,在有效回收凉水塔废热、显著提升热电厂供热能力的同时,可大量减少燃煤和供热抽汽量,其经济效益和环境效益显著,有效缓解城市供热热源紧张的现状。     

太阳能、热泵辅助燃气供热系统实验研究

搭建了太阳能、热泵辅助燃气的供热系统测试平台,对太阳能辅助燃气供热系统、热泵辅助燃气供热系统以及太阳能、热泵辅助燃气供热系统的热性能进行测试,并对三种供热系统的经济环境效益进行分析.试验结果表明,试验条件下,三种供热系统的修正后一次能源利用率分别为93.3％、92.8％、103.9％,与燃气供热系统相比,节能率分别为3...     

山东省某电厂供热系统改造项目的热负荷分析

以山东省某电厂供热系统改造发展规划项目为例，针对项目的热负荷情况进行分析，结合当地政府的供热规划，分析现有热源点的分布、相关热源点的发展规划、小容量锅炉的关停计划，对供热市场和潜在用户开展调研。根据供热介质和参数、供热指标，对工业供汽和居民采暖热负荷分类进行统计和策划，作为制定该电厂供热改造发展规划的依据。     

利用汽轮机进行供热的方法探究

介绍了利用汽轮机进行供热的多种方法,包括传统和新型的供热改造方法、前瞻性的供热方法;同时阐明了各种供热方法的实现原理、实现效果、适用范围;对各种方法的优缺点进行对比分析,可供电厂及设备制造厂参考借鉴。     

轻烃深加工装置供热改造及节能效果分析

中原油气高新股份有限公司天然气处理厂第二气体处理厂针对新旧装置供热不同的情况，对生产装置供热系统进行了工艺改造，实现了全厂两套生产装置采用新型高效节能的导热油炉进行供热。用导热油作为热载体替代原饱和蒸汽为装置供热，并对老装置供热管网进行了改造实行全厂两套装置集中供热，通过改造前后供热的参数及对能耗计量表明：改造后提高了生产供热的效率及供热的质量降低了供热损耗，增效明显。     

清洁能源供热与传统能源供热的研究

随着城市能源供应结构的调整,资源环境约束日趋强化,节能减排工作面临着严峻的形势。文中对北方某市采用清洁能源供热与传统燃煤供热进行研究,通过各种供热方式能耗与环保相关数据进行技术对比分析,为优化城市供热热源选择、降低建筑供热能耗提供参考价值。     

采暖系统热平衡技术指标及计算方法的探讨

本文通过对采暖系统的热效率、能源利用率的分析,提出了反映采暖系统的主要技术指标和采暖系统有效热的计算方法     

Heat exchanger optimization for geothermal district heating systems: A fuel saving approach

One of the most commonly used heating devices in geothermal systems is the heat exchanger. The output conditions of heat exchangers are based on several parameters. The heat transfer area is one of the most important parameters for heat exchangers in terms of economics. Although there are a lot of methods to optimize heat exchangers, the method described here is a fairly easy approach. In this paper, a counter flow heat exchanger of geothermal district heating system is considered and optimum design values, which provide maximum annual net profit, for the considered heating system are found according to fuel savings. Performance of the heat exchanger is also calculated. In the analysis, since some values are affected by local conditions, Turkey's conditions are considered.     

Future use of heat pumps in Swedish district heating systems: Short- and long-term impact of policy instruments and planned investments

Heat pumps constitute one of the major technologies used in district heating systems in Sweden. Totally about 6 TWh of heat are supplied annually by heat pumps, equivalent to 12% of the heat supplied in district heating systems. New policy instruments that have recently been introduced will change the conditions for technologies in the district heating systems. It is likely that the incentives for waste incineration and combined heat and power will be improved. This study estimates how different policy instruments, and new investments in waste incineration and combined heat and power, affect heat pumps in Swedish district heating systems. The results indicate that heat pumps are affected in both a short-term and a long-term perspective, and that heat pumps will play a less important role in district heating systems in the future. Depending on the policy instruments applied in the district heating sector, the long-term use is between 18% and 71% lower than current use. In a long-term perspective, it is in the systems which currently use heat pumps during a large part of the year that new investments in waste incineration and combined heat and power can be expected, resulting in a convergence between different district heating systems regarding how much heat is supplied by combined heat and power and waste incineration, and regarding the annual operating hours for heat pumps.     

The drying of grain with heat pumps in South Africa: A techno-economic analysis

The economic viability of air heating for grain drying with the aid of heat pumps and the viability of replacing existing heating methods (i.e. direct electrical heaters and diesel burners) with heat pumps are investigated. The energy costs of different types of heating apparatus to dry grain are calculated and, taking the different capital costs into account, the life cycle costs of the heating methods can be predicted. On comparing the life cycle costs of the different heating methods, it is concluded that heat pumps are more economical than other methods of heating provided that the apparatus is used for more than a minimum period per year. Drying of grain is usually done for periods shorter than this minimum; the result is that the use of heat pumps cannot be economically justified for the drying of grain only.     

Heat accumulators in CHP networks

In a Combined Heat and Power (CHP) network, it is sometimes optimal to install a device for storing heat from one period of time to another. Several possibilities exist. If the electricity demand is high, while at the same time the district heating load is too small to take care of the heat from the CHP plant, it could be optimal to store heat from peak periods and discharge the storage under off-peak. It might also be optimal to store heat during off-peak and use it under the district heating peak load. The storage is then used for decreasing either the district heating demand or for decreasing the electricity load used for space heating. The paper shows how a mixed integer program is developed for use in the optimization process. As a case study, the CHP system of Malmö, Sweden, is used. Further, a sensitivity analysis is elaborated in order to show how the optimal solution will vary due to changes in certain input data.     

柴油机热泵供暖系统

本文从热力学分析出发，提出了一种由柴油机驱动热泵的供暖装置。该装置可将柴油机中部分排气热损失及冷却系统热损失加以回收利用，具有较高的供热效率和很好的开发前景。     

The performance of heat pumps in service—A simulation study

A computer model is developed to simulate the performance of air-to-water heat pumps heating a house via a radiator system. The performance characteristics of the heat pumps are derived from laboratory measurements. Hourly weather observations are used to calculate the heat demand of the house and the performance of the heat pump. The effects of changes in heat pump characteristics, changes of radiator size, and changes in heat demand of the house due to insulation, are compared in terms of their effects on annual energy consumption.     

Numerical simulation and experimental validation of indirect expansion solar-assisted multi-functional heat pump

A novel indirect expansion solar-assisted multi-functional heat pump (IX-SAMHP) system which composes of the multi-functional heat pump system and solar thermal collecting system is proposed and studied in this paper. This system can fulfill space heating, space cooling and water heating with high energy efficiency by utilizing solar energy. For solar water heating mode and solar space heating mode, a dynamic model is presented and validated with the experimental results. The simulation results show good consistency with the experimental data, and the established model is able to predict the system performance at a reasonable accuracy (with the root mean square deviations less than 5%). On this basis, the performances of the IX-SAMHP system are investigated under different parametric conditions. For solar water heating mode, simultaneously operating the solar thermal collecting system and multi-functional heat pump system can be an energy efficiency method. With the solar irradiation rising from 0W/m² to 800W/m², the COP increases from 2.35 to 2.57. In solar space heating mode, the effect of the mass flow rate of water in evaporator is investigated. To balance the heating capacity and COP, the mass flow rate of water should be adjusted according to different temperature demands and heat load.     

Heat and energy requirements in thermophilic anaerobic sludge digestion

The heating requirements of the thermophilic anaerobic digestion process were studied. Biogas production was studied in laboratory experiments at retention times from 1 to 10 days. The data gathered in the experiments was then used to perform a heat and energy analysis. The source of heat was a conventional CHP unit system. The results showed that thermophilic digestion is much faster than mesophilic digestion and therefore produces more biogas in a shorter time or at smaller digester volumes. The major part of the heating requirements consisted of sludge heating. The heat losses of the digester were only 2–8% of the sludge heating requirements. The heating requirements in thermophilic digestion are about twice those of mesophilic digestion. Therefore a CHP unit system cannot cover all of the needs for successful operation of thermophilic digestion. Heat regeneration was introduced as a solution. Heat is regenerated from the sludge outflow at a temperature of 50–55 °C and transferred to the cold inflow sludge at a temperature of 11 °C. Enough heat is regenerated in a conventional counter flow heat exchanger to bring the thermophilic process to the same level as the mesophilic one. Considering the smaller digester volumes and the relatively small investment in the regenerative equipment, the construction of thermophilic digestion systems may be a very good alternative to conventional mesophilic sludge digestion systems.     

Design and thermal performance evaluation of a novel solar air heater

In the present scenario, numerous applications perform on solar energy for cooking, heating and cooling, and power generation, globally. Solar air heaters are one of these applications purposely used for, drying, timber seasoning and space heating. In the present work, a solar air heater (SAH) has been designed to produce a good exhaust temperature for long hours especially in the case of poor ambient conditions or during off sunshine hours. A mixture of desert and granular carbon in the ratio of 4:6 has been used as thermal heat storage inside the SAH. Two halogen lights of 300 W are used to increase the exhaust temperature of the SAH by placing them in the inlet and outlet ducts. All the experiments have conducted on natural and forced convection for performance evaluation on two similar design solar air heaters (with and without heat storage). The comparisons are made with two similar design solar air heaters carrying desert and granular carbon, as an individual heat storing media, to find out an optimum design of a SAH with long term heating. The thermal efficiencies of the novel SAH range from 18.04% to 20.78% of natural convection and 52.21%–80.05% with forced convection.