Advanced Materials Research Vols. 354-355

Abstract: A seawater source heat pump (SWHP) system offer an attractive option for heating and cooling residential and commercial buildings owing to their higher energy efficiency compared with conventional systems. A thermoeconomic model was developed for analysis and optimization of SWHP with residential building. The thermodynamic and thermoeconomic optimum result for SWHP in the Qingdao, china, weather conditions were obtained using MATLAB optimization toolbox. The thermoeconomic optimization results show exergy loss and EER increasing by 22.7% and 13.9% respectively, but annual production costs reduce by 29.1%.

Abstract: This study presents a simulation approach to assess the viability of solar assisted ground source heat pump system in different regions of China. A short time step model of ground loop exchanger is employed in the simulation with a 30% solar fraction. Weather data files used in the simulation are created based on Chinese Typical Year Weather (CTYW) data. Borehole length is optimized with a safety stop temperature of 0°C. The minimum Entering Fluid Temperature (EFT) decreases 1.3°C after 20-year simulation time and the team effect of ground loop exchangers is weaken as a result of spontaneous recovery of storage temperature. Borehole length replaced by area of solar collector ranges from 3.9m to 2.5m in the six cities. The results show that the annual performance of ground loop exchanger is low in heating-dominated regions and a solar assisted ground source heat pump (SAGSHP) system is needed in order to improve the system performance.

Abstract: Removed at authors request due to error in the methodology.

Abstract: The objective of the paper is to describe the performance of ground-coupled heat pump (GCHP) system in 20 years. A mathematical model for simulation of GCHP system is built based on long time-step Eskilson’s theory. The design methodology is based on a simulation that predicts the temperature response of the ground heat exchanger (GHE) to monthly heating and cooling loads and monthly peak heating and cooling demands over a number of years. The temperature response also has a secondary impact on the predicted energy consumption of the system, as the coefficient of performance (COP) of the heat pump varies with entering fluid temperature. This paper presents GCHP system can achieve better energy performance in building that heating and cooling loads are balanced all the year round. It is illustrated by performing a GHE for a 300 m2 building located in Changchun, China.

Abstract: The throttling valve used in the refrigeration system always causes energy loss. In this paper, an energy recovery device in the refrigeration system which was composed of an expander-auxiliary compressor unit to replace the throttling valve was investigated. On the basis of thermodynamic analysis, two typical arrangements which the auxiliary compressor was connected to the main compressor of the refrigeration system were compared and the system performance parameters were discussed. A prototype of an expander-auxiliary unit was manufactured to observe the expander performance using R410A as refrigerant. The results showed the reliability of the unit working in the two-phase flow condition with the rotation speed up to 21020 rpm. And the maximum increases in the cooling capacity by 3.9% and COP by 3.2% could be obtained under the testing condition.

Abstract: In order to solve the problems of pressure drop and leakage in the refrigerant circuit, a novel continuous adsorption system suited to use low heat source (75-85 oC) was designed and set up. To analyze and compare with the conventional system to reveal the similarity and difference, this paper sets up the mathematical models for these two systems. The adsorbers, condensers and evaporators in these two systems are exactly the same and the two systems are compared by working at the identical conditions, which is not feasible in real experimental lab. All the parameters and models used in this calculation are based on experimental results. Analysis demonstrates that the two kinds of system have very close performances, that is, the novel system has a relatively higher cooling capacity while the conventional system has a relatively higher COP.

Abstract: Solar assisted heat pump system(SAHP) has a wide and wonderful future for its excellent performance in energy saving and environment protection. Solar assisted heat pump system for floor heating is combined by solar assisted heat pump and floor heating. Presents the operating principal and key equipments and designs solar collector, thermal storage container, floor-coil radiator and so on， discusses the feasibility of introduction of a combined heating system for an energy building in Qingdao. On the base of this, two types of energy supply systems, the conventional system(gas heating and SAHP system, were set. Those two types of systems were evaluated regarding energy efficiency and environmental load. According to the results, compared with the conventional system, SAHP system was capable of reducing the primary energy consumption and CO2 emission, respectively 20% and 19.2%.

Abstract: Aiming at a high-power turbine of a certain 1000MW electric-generating unit, three calculation schemes were programmed to calculate the thermal parameters of steam in the flow passages. The comparison and analysis between the calculating results and the design values under the turbine rated load (TRL) verified the feasibilities of the calculation schemes. The thermal parameters of steam in flow passages under variable operating conditions were also obtained by the calculation. The calculating results could be the basic data needed by thermal stress analysis and life prediction of the turbine.

Abstract: Based on the supercharged boiler thermodynamic calculation method and turbocharged set characteristic calculation method, an integrated model used for studying the matching performance was built, and then the matching performance calculation program chart was made. Taking a type of marine supercharged boiler as the research object, the matching performance of supercharged boiler and turbocharged set, which was changed with excess air coefficient, was studied under different loads. The model is proved correct and effective by the comparison of the design value and calculation value. The analysis results can provide a strong technology support to the supercharged boiler set’s optimized design and safety operation, which means theoretical and practical significance

Abstract: In order to develop stamping well pump with high efficiency, 4SP14 stainless steel stamping well pump was set as an example. Combined with the features of stamping technology, this research was taken on raising the efficiency of stamping well pump, using hydraulic design of impeller and CFD and regression test method. The experiment was designed with four factors including impeller inlet angle Δβ1, impeller outlet angle β2, and impeller outlet width b2 and inlet width of guide vane B3. 30 groups of programs were designed according to CCD central composite test method. The whole flow field of well pump at the operating point was simulated by FLUENT using the standard k-ε model, SIMPLE algorithm, first-order upwind scheme. 30 group of efficiency were obtained. Use regression equation to fit the function relationship between the efficiency value and each factor. Through the analysis of the regression equation, the optimal combination of geometric parameters can be found as inlet angle 4º, outlet angle 27.5º, outlet width 9.5mm and inlet width of guide vane 11.5mm. After manufactured and tested according to the above geometric parameters, the efficiency of the optimal model pump reaches 60.28%, which reaches the international advanced level.