Cheng Ying Qi

Heat Imbalance Analysis of a Hybrid Ground-Source Heat Pump System

Operating data in the last two years of a hybrid ground-source heat pump system (HGSHPS) were analyzed, and were contrasted to TRNSYS simulation results. Heat extraction from the borehole heat exchanger (BHE) of ground-source heat pump system (GSHPS) was too much larger than the heat injection, but heat extraction from the borehole thermal energy storage (BTES) of solar assisted GSHPS (SAGSHPS) was too less than the heat storage, in 2012. Serious problem of heat imbalance of BHE occurred, and the GSHPS almost could not work in the late heating season of 2012. An adjusted operating strategy was utilized in 2013. The ground temperature imbalance for GSHPS and heat excess for SAGSHPS were resolved. It is important to monitor the operation of HGSHPS to resolve the heat imbalance problem.

The Experimental Analysis on the Regularity of Heating Load in Buildings Using Heat Meters with On-Off Time and Area Method in Shijiazhuang Area

Based on the heating load experiment adopting on-off time and area measuring method of typical heat users located in different places of different buildings in Shijiazhuang, the heating loads of the heat users which are summarized as two typical heat using modes are studied in this paper and the heating loads in the whole winter heating season of the building is estimated. The results shows that with the user’s heat adopting ratio in these two modes increases, the corresponding heating load is lower, the heating load distribution curve gets smoothly in the whole heating period and the peak value of the system heating loads reduces. This regularity of heating load distribution is beneficial for enhancing the stability of heating system and the thermal efficiency of the heat source.

Experimental Analysis of the Coefficient of Building Comprehensive Property

According to the heating theory of heat balance and heat consumption of buildings[1], derivate formula for the coefficient of building comprehensive property. Choose five typical districts for the Study. The coefficient of building comprehensive property can be used as the secondary side of adjustment and control for the water temperature conditions and methods[2]. By all typical districts data collection and analysis, verify that the construction of the coefficient of building comprehensive property in guiding role of central heating system control.

Optimization Settings Application Analysis of Peak-Shaving Heat Source in Large Scale Flow Loop Heating Network

Set up the optimized target function by theoretical analysis of peak-shaving heat source optimization settings, determined optimal locations of peak-shaving heat source and capacity matching relation by comparison analysis. Concluded and analyzed optimal locations and heat capacity matching rule of each heat source when multiple heat sources worked jointly. Results and conclusions provide a valuable reference to the formation on combined economic operation pattern in large scale loop network using multiple heat sources.

Application of Mine Water for Water-Source Heat Pump System

Mine water and mine return air is good for the renewable energy due to heat storage underground, and the recycling has been a new technology of the energy utilization in water source heat pump system. Utilizing the waster heat of coal mine is beneficial in reducing the coal consumption of winter heating boiler or even replacing it completely. Comprehensive analysis the research situation and the project example, this paper points out that the technical of mine water applied for water-source heat pump system is feasibility in the practical project and theory in view of advantages, like energy saving, environmental protection, high efficiency and short payback period, etc. Therefore, application of mine water for water-source heat pump system is a new advanced energy-saving technology.

Analysis on the Indoor Temperature in Households of Heating Metering with Work Mode

Based on the theory of the room heat balance ,this paper discussed the 24 hours indoor temperature with work mode ,and concluded that indoor temperature changed in three stages:steady period, cooling period and warming period .By testing the actual indoor temperature of different heating ways with work mode and comparing the cooling process of theory results with field measurements after the temperature control valve closed ,concluded that the theory results and field measurements were basically the same and if the temperature control valve was closed less than ten hours in the daytime, the largest reduction of indoor temperature were about 2 ~ 3 °C, and it wont reduce peoples comfort with work mode when indoor or outdoor temperature was high.

Numerical Simulation of Flow and Heat Transfer Characteristics in Rectangular Channel with Novel Longitudinal Vortex Generators

A novel combined longitudinal vortex generator, comprising a rectangular wing mounted with an accessory rectangular wing, was introduced and the turbulent flow and heat transfer characteristics of a rectangular channel with rectangular winglet pair and combined winglet pair were numerically analyzed. The effects of six parameters were examined. The results show that in the range of the present study, the increase of the six parameters can result in the increase of heat transfer and pressure drop. Specially, the pressure drop decrease at large value of the distance of accessory wing from the channel bottom. The effect of the main attack angle of the combined winglet pair is somewhat different to that of the rectangular winglet pair. The heating plate temperature of the channel with combined winglet pair is lower than that of the channel with rectangular winglet pair, and hence the heat transfer is enhanced.

The Computational Analysis of Parameter Setting on Secondary Network Distribution Heat Source in Central Heating System

Two combined operation modes of basic heat source and distribution heat source are described, the possible values of basic heat source capacity coefficient α under these two combined operation modes in each region with heating provision are explored, the theoretical calculation formula of distribution heat source opening temperature and closing temperature is derived, and figure out distribution heat source opening temperature and closing temperature of each region with heating provision according to the recommended basic heat source capacity coefficient α, draw that if heating temperature is 5°C, distribution heat source can not only reinforce the peak, but also run the valley in these regions which are colder than Yinchuan, but distribution heat source can only reinforce the peak in other regions.

The Effectiveness Analysis of Some Large-Scale Central Heat Supply System Energy Conservation Transformation

In heat source ability sufficient situation, some phenomenon occurred in some central heat supply system, such as uneven heating, serious disorders, the far-end heating reliability was insufficient. To improve the heating security and reliability, this article carries on an investigation test, problem analysis, Clears the crux of the problem, Proposes the corresponding transformation plan, and carries on the effective analysis of the actual heating effect after transformation. The results show that after transformation, the actual heating network runs well, increases the heating area, improves the heating security and reliability, provide the reference for other large-scale pipe network energy conservation transformation.

Study on Indoor Thermal Comfort of Heating System with On-Off Valve Regulation

The indoor thermal comfort labels for the heating system with on-off valve regulation has been proposed by Fanger’s PMV/PPD. Experiments were conducted to investigate the thermal comfort of heating system with on-off valve regulation in point to the living habits and clothing situation of residents in North China. The computational fluid dynamic (CFD) software AIRPAK was adopted in the evaluations. The indoor airflow distribution, PMV of different transient heating process were simulated. The indoor human comfort and changes were analyzed and compared. It was found that the indoor thermal comfort is satisfactory for the heating system with on-off valve regulation.