Voice of Experiment and Research

Development and application of building absorption heat exchanger

Zhu Chaoyi; Xie Xiaoyun; Jiang Yi

Building Energy Efficiency Research Center of Tsinghua University

Abstract: Absorption heat exchanger is a new type of heat exchanger suitable for heat exchange between two extremely mismatched fluids. It is suitable for large temperature difference heating systems that use waste heat as a heat source and replace the conventional heat exchanger at the end. Heat exchange from primary network to secondary network. This paper has developed a small absorption heat exchanger with a vertical segmented structure, which improves the performance of the absorption heat exchanger, reduces the unit capacity of the unit, and realizes the building absorption heat supply for independent heating in a single building. mode. The measured heat exchange efficiency of the developed unit has reached above 1.2, and it has been used as a building-type absorption thermal power station in heating projects in Chifeng and Hohhot to independently heat a single building and achieve good heating results. .

Keywords: heat pump; heat exchanger; building heating; heating system;


Measurement and analysis of the operating performance of a two-stage large temperature difference absorption heat exchanger applied in Taiyuan

Yi Yuhao; Xie Xiaoyun; Jiang Yi

Building Energy Efficiency Research Center of Tsinghua University

Abstract: There is a large amount of waste heat directly discharged in our industry. With the introduction of the national "clean heating" important directives and the continuous expansion of heating needs in northern cities, related research and engineering cases on how to effectively recover these industrial waste heat have also been proposed. Fu Lin et al. Proposed the use of an absorption heat exchanger to reduce the return water temperature of the primary network and achieve a large temperature difference. This method can effectively expand the scale of heating without changing the existing pipe network system, and at the same time can recover more More low-grade waste heat resources to achieve clean heating. At present, absorption heat exchangers have been put into operation in many places and have achieved good practical results. In this paper, the operating performance of the two-stage large temperature difference absorption heat exchanger used in Taiyuan City during the heating season of 2018-2019 was measured and analyzed. Multiple units with different capacities were selected for testing. The operating load rate of different units is between 5% and 98%. The unit can operate stably and efficiently at each load rate. The measured temperature efficiency is between 1.2 and 1.43. The outlet water temperature of the primary network can be reduced to less than the secondary temperature. Net water temperature is 10K ~ 25K. The actual measurement results show that the unit can operate normally in the extreme working conditions of the early and late cold season, and the temperature of the water inlet to the network is as low as 65 ℃, that is, the unit can operate normally under the full range of operating conditions. This result has guiding significance for the pattern design of further utilization of the system.

Keywords: absorption heat exchanger; large temperature difference heating; flow ratio; temperature; efficiency;


Impact of northern winter heating on atmospheric environment

Chen Jiayang; Xia Jianjun; Shan Ming; Liang Wei; Wang Zhijie

School of Architecture, Tsinghua University; Dongfang New Energy Co., Ltd., SPIC

Abstract: In northern China, heating in winter consumes a large amount of fossil fuels. Pollutants produced by its combustion are one of the important causes of haze. In this paper, the heat source emission factors of combined heat and power plants, boiler rooms, and rural biomass and bulk coal are analyzed and analyzed through research methods such as relevant standard investigation, actual emission data of heat source pollutants, and field measurements. Indirect emissions are discussed. On this basis, this paper divides the "2 + 26" urban agglomeration into six sub-urban agglomerations based on the correlation analysis, and calculates the direct winter heating emissions in each region.

Keywords: clean heating; PM2.5; combined heat and power; “2 + 26” urban agglomeration;


Research on Multi-source Complementary Combined Heat Pump Clean Water Preparation System

Sun Linna; Li Yan; Li Wentao; Xu Kangwu; Sun Jufeng; Song Xiangyu; Tian Xiaofeng

School of Civil Engineering and Mechanics, Yanshan University

Abstract: Domestic hot water energy consumption has become a part of building energy consumption that cannot be ignored. Wastewater discharged from baths, swimming pools and other places accounts for about 50% to 60% of total heating energy, which has great energy saving potential. Based on this, this paper proposes a new type of hot water preparation system that organically combines sewage source heat pump and air source heat pump. By adjusting the ratio of the output power of the two heat pumps, the system achieves energy-efficient operation throughout the year. Heat cost. The new system uses a university project as an example to compare and analyze with the conventional method of preparing hot water. The results show that the new system has an energy efficiency improvement of 23.3% to 58.3% and a heating energy consumption reduction of 20.0% to 36.8% compared with the conventional heat pump system; Compared with the conventional hot water preparation method, the energy cost is saved by 56.7% ~ 64.0%, which provides a new idea for hot water preparation in the bath.

Keywords: hot water preparation system; wastewater recovery; waste heat; heat pump;


Test and analysis of heat transfer coefficient of directly buried thermal insulation pipeline

Feng Wenliang; Bai Dongjun

Beijing Public Utilities Science Research Institute

Abstract: This paper introduces the definition, calculation method of total heat transfer coefficient of directly buried thermal insulation pipes and the principle of measuring total heat transfer coefficient using heat flow meter method. According to the test method, the design and implementation of the test system for the total heat transfer coefficient of the directly buried pipeline in the laboratory are introduced from the aspects of the pipeline medium circulating heating system, the test sandbox environment, environmental monitoring, test sample preparation and measurement point layout, and test steps. The total heat transfer coefficient is tested in the system with actual samples, and the temperature difference method is used to verify the feasibility and accuracy of the test method and system.

Keywords: buried pipeline; heat transfer coefficient; heat flow meter; thermal conductivity;


Brief analysis on the development of clean heating in winter

Cai Chunlei

Yantai City Public Utilities Service Center

Abstract: The author of this article is based on the strategic deployment of the State Council to win the Blue Sky Defense War, combined with national and local policy requirements for accelerating the promotion of clean heating, and analyzes some of the experiences and deficiencies in the promotion. Discuss the situation and trend of clean energy development such as "electricity replacing coal", and put forward some reflections and suggestions.

Keywords: clean heating; clean energy; development;


Operation Management World

Method for predicting and analyzing heating load based on weather forecast

Fan Min; Yang Limin

Taiyuan Heat Power Group Co., Ltd.

Abstract: Analyzing the correlation between the weather forecast and heating load of Taiyuan City during the heating season 2018-2019, the results show that the number of days with outdoor temperature below 0 ° C on that day accounts for 54% of the total heating season, and the heating heat load and outdoor temperature on that day show Linear negative correlation; the wind speed correction heat load coefficient distribution is concentrated between 3.38% to 6%. Considering the overheating days after wind speed correction is 43 days, but the overheating ratio decreases from 10.4% to 5.94%; in the cold season, sooner or later The outdoor temperature difference changes little. By orderly switching and adjusting the heating network system, the heat supply and demand balance of the heating network system is quickly achieved, and energy saving and stable guarantee of the daily heating load; the large deviation between the predicted room temperature and the actual room temperature, and the entire network balance automatic control system flow distribution The balance is easy to be broken, and the dispatcher needs to adjust the operation of the first heating supply station, the operation of the unit with large temperature difference, and the operation and exit of the network-wide balance software in a timely manner.

Keywords: meteorological forecast; thermal index; balance; adjustment;


Analysis of Hydraulic Conditions Based on Taikoo First Class Network Operation Regulation

Fan Min; Ji Kedan

Taiyuan Heat Power Group Co., Ltd.

Abstract: This paper takes Taikoo First Class Network as the research object, and uses GeoPipe hydraulic calculation software to perform hydraulic analysis on various working conditions. Combined with the load of Taikoo First Level Network, a distributed variable frequency pump is reasonably set, and the hydraulic conditions under the flow control at the gate and the multi-heat source networked operation mode are analyzed based on the actual flow matching and heat source heating capacity. Taking the fault condition of the main line as the analysis object, an optimization scheme of Taikoo First Class Network is proposed to guide the production operation.

Keywords: heat network; hydraulic analysis; distributed variable frequency pump; multi-heat source network; fault; optimization;


Preliminary Study on Quick Location and Regional Isolation of Swire Leakage Network

Shi Guanghui

Taiyuan Heat Power Group Co., Ltd.

Abstract: This article is aimed at the problem that the first-level grid sudden leakage accidents in the Taiyuan (Taigu) large temperature difference long-distance heating project can not be quickly located and isolated in the past three years, and a type of pressure signal is used for positioning and the regional valve is quickly isolated. Phased research was carried out on this method. After the overall study is completed, the safety of the entire Swire system will be further improved, and the impact of the overall system outage will be reduced.

Keywords: heat network; leakage; pressure; location; isolation; safety;


Selection of Distributed Water Supply System of Swire Primary Heating System

Wang Linwen; Xu Zilong

Taiyuan Heat Power Group Co., Ltd.

Abstract: With the development of cities, the construction scale of central heating systems in large cities is getting larger and larger, and the heating pipe network is becoming more and more complicated. In order to ensure that the heating system is not overpressured, vaporized, and emptied, the system must maintain a constant pressure, so the heating system must be equipped with a water supply system. The safe operation of the water supply system is related to the safe and stable operation of the entire heating system. This paper introduces the water supply system of the primary pipe network system of the Taikoo long-distance heating system. By using distributed and supplemental water supply and centralized constant pressure operation, it ensures the safe and stable operation of large-scale heating systems in cities.

Keywords: heating network; distributed; water supply; security;


Analysis of the main influencing factors of return water temperature based on Taikoo large temperature difference heating primary network system

Wang Linwen; Zheng Zhizhong

Taiyuan Heat Power Group Co., Ltd.

Abstract: Taikoo's large temperature difference long-distance heating system is divided into a high-temperature network, a primary network, and a secondary network after the user's heat exchange station. It has run three heating seasons, and the heating area has increased year by year. The main measures to reduce the return water temperature are the heat exchange stations on the primary grid side. This article details the heating area ratio and operating conditions of the thermal stations and plate heat exchange power stations of the large temperature difference units used by the various units of the Taikoo Primary Network. A comparative analysis of the return water temperature of the primary network in each heating season of the heat unit was found to be limited by the heat exchange performance of the plate exchange. At the same outdoor temperature, the area of the thermal power station with different heat exchange forms and the primary network flow of the plate heat exchange station If it is too large, the temperature of the return water of the system is higher than the theoretical weighted average temperature. In addition, the high proportion of abnormal operation of large temperature difference units is also the main reason for the high return water temperature of the system. The heating area of the heating unit is calculated according to different heating methods.The proportion of heating by the radiator is significantly larger, but in actual heating, the temperature of the secondary network return water of the radiator heating control is higher than that of the floor heating, which has a certain temperature for the primary network. influences. In order to ensure the heating effect, the actual heating index is high and the heat consumption is not increased, but the heating capacity is reduced, which affects the effect of large temperature difference.

Keywords: return water temperature; heat exchange form; operating effect; adjustment method; heat consumption;


Analysis of the Running State of the Long-distance Heating Pipeline Ripple Compensator

Zhao Hong; Wang Yanan

Taiyuan Heat Power Group Co., Ltd.

Abstract: The compensator is an important thermal displacement compensation component in the urban heating pipe network. The determination of its operating status can help operators understand the remaining life of the compensator and ensure the safety and stability of the heating network operation. This article attempts to use 105 sets of telescopic compensation data of the tunnel section and overhead section ripple compensator obtained during the three heating seasons of the Taikoo long-distance heating pipeline to analyze the relationship between the compensator's expansion amount and the system operating parameters. Method for judging the operation status of the compensator. At the same time, comprehensively understand the factors that affect the operating state of the compensator, and judge its operating state more accurately.

Keywords: long-distance heat supply pipeline; overhead section; compensator; influencing factors; operating state; displacement ratio;


Statistics and Analysis of Energy Consumption of Thermal Power Station in Central Heating System

Ziaru

Taiyuan Heat Power Group Co., Ltd.

Abstract: The situation of energy shortage in China is becoming more and more obvious. The heating industry, which accounts for a large amount of energy consumption, should pay great attention to all aspects of energy consumption in operation in order to maximize energy savings. In the heating period of the 2018-2019 heating season, this article is divided into 4 categories according to the construction year and heating type of the buildings provided (non-energy-saving buildings before the 1990s, non-energy-saving buildings after the 1990s, energy-saving building radiators, and energy-efficient building floor heating). Select a total of 90 heating stations in a heating company's centralized heating system as the site survey site, use the corresponding measurement system in each heating station to measure, count, and analyze the heat, electricity, and water consumption of the station, and organize the analysis to obtain the heating company The average energy consumption level and total average energy consumption level of various stations, and find and summarize the high energy consumption influencing factors in heating operation, to provide certain guidance for the design, operation, and management of heating systems.

Keywords: central heating; thermal station; energy consumption; analysis;


Optimal solution of urban heating system based on steady-state simulation model

Gao Qingwei; Li Ziyang

Beijing Thermal Power Group Sanhe Xinyuan Heating Co., Ltd.

Abstract: For urban civil heating systems, there are cases of year-round transformation and expansion. The heating network structure and hydraulic conditions frequently change. The operating mode of the heating network needs to be adjusted accordingly. Through modeling and simulation calculation of the heating system, The simulation and deduction of the operating state of the physical heating system in the computer system can reduce the cost of trial and error, and can quickly obtain the optimized decoupling method of the heat network to guide the stable operation of the heat network. For the centralized heating system of Sanhe Xinyuan Heating Co., Ltd., before the heating season begins, use simulation software to model the heat network and set the decommissioning target. Select multiple operation decommissioning methods of the heating system for simulation calculation. . The results show that, based on the calculation results of the simulation software, the operating personnel can be guided to quickly select the optimal solution to be put into operation. The operation practice in the heating season proves that the simulation software calculation results are consistent with the actual operation results. The simulation calculation method can significantly improve the flexibility, balance and comfort of the heating network operation.

Keywords: simulation model; optimization solution; heating system; flexibility; hydraulic conditions;


Preliminary Study on Measures to Improve Heat Transfer Efficiency of Plate Heat Exchanger

Zhang Dazhi; Liu Yuhe;

Liaoning Jinzhou Thermal Power Co., Ltd.

Abstract: The plate heat exchanger is the core equipment of the heat exchange station in the indirect heating mode. Its heat transfer efficiency directly affects the heating effect and heat energy utilization efficiency. This article finds out various reasons for the theoretical analysis of the reduction of board replacement efficiency, and combines the actual work to explore the correct selection method and operation management measures of board replacement to improve its heat transfer efficiency and save electricity and heat consumption.

Keywords: plate heat exchanger; heat transfer efficiency; temperature difference; operation adjustment; energy saving;


Planning and Design

Discussion on the Minimum Ring Stiffness of Urban Heating Directly Buried Thermal Insulation Plastic Pipe

Yan Yongpeng; Wang Huai; Wang Yan

North China Institute of Municipal Engineering and Design, China Municipal Engineering Co., Ltd .; Key Laboratory of Ministry of Industry and Information Technology for Human and Environmental Environment in the Cold and Urban and Rural Areas of Harbin Institute of Technology

Abstract: This paper studies the ring stiffness of PE-RTⅡ, a direct buried thermal insulation plastic pipe for urban heating, and obtains the minimum ring stiffness and the minimum ring stiffness under applicable heating conditions.

Keywords: plastic pipe; minimum ring stiffness; relative stiffness; fitting formula;


Reserve and reliability evaluation of long-distance heating pipeline structure

Wang Yan; Wang Wei; He Jinjin; Yan Yongpeng

School of Architecture, Harbin Institute of Technology, Key Laboratory of Ministry of Industry and Information Technology for the Human Settlement Environment in the Cold Urban and Rural Areas; China North Engineering Design & Research Institute Co., Ltd.

Abstract: Due to the pressure of urban haze control and the demand for waste heat utilization, the heat supply source is gradually away from the city, forming a long-distance heating pipeline that is characterized by long-distance transportation and large-scale heating area. In order to control the impact range of long-distance pipeline component failures and prevent serious consequences, this article uses the accident-free working probability index as the basis for reliability evaluation. The influence of heating period and pipeline length on the reliability of each model is shown. The results show that the reliability level of the two-regulated long-distance pipelines is too low, while the reliability of the three-regulated and four-regulated long-distance pipelines has increased significantly and remained above 0.95. Long-distance pipelines should be designed in the form of three-regulation or four-regulation in order to make use of the multi-regulatory structure reserve capacity and improve the reliability level.

Keywords: heating; reliability; long-distance pipeline; structural reserve; multi-regulation;


HVAC design of a super high-rise building

Yang Peng; Hou Jing; Zhang Yanfeng

Hebei Architectural Design & Research Institute Co., Ltd .; Northern Engineering Design & Research Institute Co., Ltd.

Abstract: This article introduces the design of HVAC in a super high-rise building, elaborates the configuration of cold and heat sources, the partition design of the air-conditioning water system, and the automatic control method of the air-conditioning system. Similar designs are provided for reference.

Keywords: building; HVAC; design; cold and heat source


Selection of Constant Pressure Method for Heating System of Atmospheric Hot Water Boiler

Kang Hongmei; Li Xingchunxia;

Beijing Gas Thermal Engineering Design Institute Co., Ltd.

Abstract: A comprehensive carding and summarizing of constant pressure methods for atmospheric hot water boilers. The conventional boiler backwater pipe constant pressure method is prone to cavitation problems. When the hot user is higher than the boiler, the phenomenon of emptying and air blocking is easy to occur, and the system is not easy to control when the two-point constant pressure is used. This article distinguishes between high and low users, compares the different constant pressure methods of the two systems, analyzes the pressure conditions, and draws the hydraulic pressure diagrams of different system forms, which is convenient for designers and operators to choose the optimal constant pressure method and solve it according to the actual project. Problems during operation.

Keywords: hot water boiler; constant pressure; pump cavitation;


Clean energy heating

Analysis of the Development and Status Quo of Russian Nuclear Energy Heating Technology

Solomykov Aleksandr; Zhao Jinling

Department of Construction Engineering, Dalian University of Technology

Abstract: The development history of nuclear energy heating in the former Soviet Union and Russia is briefly introduced. It is divided into five more obvious development stages. The key technologies of nuclear heating in Russia are given, including the low temperature nuclear heating plant of the former Soviet Union's AST-500 reactor, the extraction of steam from a nuclear power plant, and the world's advanced floating nuclear thermal power plant. The main data of Russian nuclear power plant heating are analyzed, which shows that the main technology of nuclear power heating in Russia is nuclear power plant heating; the strategic policy of nuclear power heating in Russia in the next few years is given, and the positive effects of nuclear power heating development between Russia and China are pointed out.

Keywords: Russia; nuclear energy; heating; clean energy;


Comparison of energy efficiency of different natural gas heating methods

Wang Ming; Wu Jie; Zhang Chenghu

Shandong Urban and Rural Planning and Design Institute

Abstract: Based on the calculation of energy utilization efficiency, this article compares five natural gas heating methods (gas wall-hung boilers, district gas boilers, direct-fired gas absorption heat pumps, distributed energy, and gas-steam combined cycles) common in northern regions. The analysis provides a reference for different users to choose efficient heat sources according to local conditions. The research results show that although the comprehensive utilization efficiency of the gas-steam combined cycle is high, it is not suitable for centralized heat source development at the present stage; followed by the increase of gas boilers and distributed energy sources of absorption heat pumps, which have energy-saving potential and good development space, and can be long-term As a supplement to the city's concentrated large heat source or to independently undertake the heat load demand; the heating efficiency of gas wall-mounted boilers is relatively low, but due to individual heating, it is encouraged to develop in areas where the heating network cannot be installed and new rural communities.

Keywords: energy; utilization efficiency; natural gas; heating mode; heat pump; energy saving


Energy conservation

Technology analysis and thermal energy calculation of waste heat utilization and white fog elimination of gas hot water boiler

Wang Hao; Li Jun; Wang Xiaonan; Song Lei

China Zhongyuan International Engineering Co., Ltd .; Beijing Tide Thermal Technology Development Co., Ltd.

Abstract: In recent years, with the gradual improvement of energy saving and environmental protection requirements, the use of flue gas waste heat and whitening fog technology has been widely used in gas-fired hot water boilers. This article briefly explains the technical principles of flue gas waste heat and whitening fog, and through the analysis of the composition of the flue gas, combined with the calculation formula of the air enthalpy and humidity diagram, the calculation of the condensed water content, the moisture content, and the specific enthalpy of the flue gas are fitted. The reheating state points, and then calculate the heat change and system thermal efficiency at different stages of the system, provide a reference for the research and application of the waste heat utilization of the gas hot water boiler and the white fog elimination technology.

Keywords: flue gas; waste heat recovery; whitening fog; condensation; heat supply;


Intelligent Control Garden

Research and Practice of Adaptive Operation of Heat Exchangers Based on Thermal User Room Temperature Control

Li Min; Feng Tiejun; Wang Longchen; Zhao Yan; Yang Huayi; Li Yi

State Power Investment Northeast Electric Power Co., Ltd. Dalian Kaire Branch; Dalian Haixin Information Engineering Co., Ltd.

Abstract: Aiming at the current situation and problems of production management of Dalian Kaire Branch, this paper takes “second network balance as the key point, automatic operation of heat exchange stations as a means, and room temperature precise control as the goal” as the guiding principle, and formulates the secondary network hydraulic balance. The specific technical schemes of transformation, room temperature monitoring and control system upgrade were implemented in 6 regional heat exchange stations in Qingsong, and the implementation effects were analyzed. The results show that after the implementation of the secondary network balance reconstruction, room temperature monitoring, and control system upgrade, not only the user satisfaction is improved, but also the thermal and electrical indicators are significantly reduced, and the energy saving and consumption reduction effects are obvious. The technical scheme is of reference significance for energy-saving and consumption-reduction of heating enterprises and improvement of heating quality.

Keywords: hydraulic equilibrium; room temperature analysis; room temperature control; adaptive operation


Energy-saving test and diagnosis of residential thermal power station

Liu Jin; Zhen Haoran; Feng Wenliang

Beijing Public Utilities Science Research Institute

Abstract: This article introduces the basic composition, energy-saving testing and diagnostic methods of district heating stations in district heating systems. And through the actual project, the whole process of energy-saving test of the thermal station is described from the system overview, measurement point arrangement, data collection and processing, etc., from the thermal load condition, pressure loss situation, plate heat transfer effect, secondary network water pump in the station. Several aspects of the operating situation are analyzed from the perspective of overall energy saving of the heating system, and suggestions for energy saving improvement are put forward.

Keywords: thermal station; heat transfer effect; pressure loss;