Proceedings of the 12th International Conference on Cold Climate HVAC & Energy (Volume 1)

Inhaltsverzeichnis

1. Renewable and Waste Energy Utilization

   1. Frontmatter

   2. Research on the Evaluation Weight of Green Office Buildings Based on the Entropy Weight Method: A Case Study of Cold Regions

      Yijing Ge, Long Ni, Chong Meng

      Abstract

      With the systematic advancement of dual carbon goals and the Healthy China strategy, it is highly valuable to explore the balance and optimization of the weights assigned to the performance indicators of “resource conservation” and “health and comfort” within the evaluation framework. This study focuses on the functional characteristics and energy consumption patterns of office buildings. Based on 20 samples of green office buildings nationwide, the entropy weight method is employed to construct a differentiated evaluation model. The analysis emphasizes three core indicators: energy efficiency (including the energy efficiency of cold and heat source units, energy consumption per unit building area, and renewable energy utilization rate), thermal comfort (measured by PMV and air change rate), and environmental quality (assessed through PM_2.5 levels, formaldehyde concentration, and background noise). We calculated the weights using the entropy weight method, with particular attention given to analyzing the applicability differences of samples from cold regions. This research provides robust data support for refining the classification of building categories and climate zones in the “Green Building Evaluation Standard”.

   3. Experimental Study on Direct Expansion Solar Assisted Heat Pump System Based on PV/T Panel

      Peng Hao, Ji Peidong, Shou Chunhui, Luo Zhouyang, Hua Wei, Sun Shien

      Abstract

      This study experimentally investigates the operational characteristics of a direct expansion solar assisted photovoltaic/thermal (PV/T) heat pump system under varying conditions. A setup employing 380Wp PV/T modules was developed to analyze the effects of solar irradiance, ambient temperature, and electrical efficiency on power output, heat collection, and heat pump performance, establishing empirical correlations. Empirical correlations were established to characterize these relationships. Results indicate that PV/T module temperature reduction, relative power generation gain, heat collection power, thermal collection factor, and system coefficient of performance (COP_sys) increase with elevated solar irradiance and ambient temperature. Conversely, power generation efficiency decreases with higher ambient temperature, while the heat collection factor declines with increased solar irradiance. Furthermore, COP_sys is inversely proportional to PV/T module electrical efficiency. Within the test range, the system exhibited electrical efficiency, relative power generation gain, and heat collection factor of 17.98% to 19.64%, 1.04% to 12.16%, and 51.18% to 870%, respectively. The heat pump achieved a COP_sys range of 1.32 to 5.73, representing a variation of −27.79% to 27.03% compared to an air-source heat pump. When considering combined power generation and consumption, the system demonstrated a lower heating energy consumption factor (0.03 to 0.76) than air-source heat pumps during daytime operation.

   4. Operational Performance Analysis of an Integrated Solar PV/T and Air Source Heat Pump System

      Fu Liang, Haoran Ning, Zeguo Qiu, Jianfeng Qian, Huaxin Wu, Bin Zhong

      Abstract

      This project studies the coupling of solar photovoltaic-thermal PV/T components with air source heat pump for combined heat and power supply system. On the basis of improving the efficiency of solar photovoltaic power generation, it effectively utilizes the solar thermal energy resources. The team built this combined heat and power supply system in Fuzhou City and conducted experiments. The results show that when the light intensity reaches saturation, the maximum power generation of the PV/T component is 0.42 kW. The power generation efficiency of the PV/T system ranged from 12.19% to 16.35%, with an average of 15.16%. The average thermal efficiency of the PV/T system is 21.58%. This system significantly reduces the surface temperature of the photovoltaic module plates. The best water volume for the system’s water tank is 450 L. This system is best suited for 32 PV/T panels, with an average COP of 5.36. This system was compared with PV/T-ASHP (air source heat pump) in cold regions. The average COP increased by 2.89. After applying the enhanced vapor injection in cold regions, the average COP rose to 3.86. When using soil-source heat pumps in cold regions, the system’s average COP is 4.62, which demonstrates significant advantages. This system can effectively achieve combined heat and power supply, and has considerable economic and environmental benefits, providing reference for the low-carbon and energy-saving operation of buildings.

   5. Experimental Evaluation of Energy Conversion Characteristics in Composite Photovoltaic/Thermal System with Phase Change Material

      Siyuan Xiang, Daifeng Li, Xiaoqin Sun

      Abstract

      The output power of photovoltaic modules (PV) is easily affected by high temperature. To address this issue, a PV/T-PCM composite system integrating phase change material (PCM), metal fins, and heat exchange tubes was proposed, designed, and tested. The performance of four photovoltaic cooling systems, namely PV, PV/T, PV-PCM, and PV/T-PCM, was compared and studied. The results indicate that the average temperature of the PV/T and PV-PCM systems dropped by 8.49 °C and 11.65 °C, respectively, in comparison to the reference PV system, and the output power rose by 12.77% and 14.45%, respectively. Additionally, the heat storage in the PV-PCM system was 8446.49 kJ. However, both the PV/T and PV-PCM systems endure overheating under long-term operation. The average temperature of the PV module of the PV/T-PCM system is 44.96 °C, which is 14.49 °C lower than that of the PV system, and the peak temperature is delayed by 72 min. The average daily output power of the PV/T-PCM system is 386.77 Wh, which is 35.54% higher than that of the PV system, and the total heat storage capacity is 14494 kJ. Compared with the PV-PCM system, its thermal storage efficiency is increased by 71.6%.

   6. Numerical Study on Convective Heat Transfer Characteristics of Photovoltaic Arrays and the Covered Flat Roof Surfaces

      Yalan Yin, Xusong Tian, Jiawei Wang, Fujian Jiang, Wenhui Ji, Jinzhi Zhou

      Abstract

      The convective heat transfer coefficient (CHTC) at photovoltaic (PV) panel surfaces are critical for predicting its power output performance. However, the air flow condition and CHTC present discrepancy at different regional spaces of PV arrays due to wind- shielding effect. Existing studies often assume uniform coefficient for the thermal performance calculations, leading to an inaccuracies in PV array power generation prediction. In this paper, a three-dimensional numerical heat transfer model is established for PV array-roof system, and the effects of layout parameters of PV array on CHTC are systematically analyzed. The results demonstrate that installing PV array reduces partial CHTC on the roof, and significantly cause differences in heat exchange characteristics between first-row and rear-row PV panels. While the effect of PV panel’ size and PV array row space on CHTC are minimal. When the tilt angle of PV panel increase, the CHTC between roof and first-row PV panel (h_pvr1) and CHTC between air and roof (h_ra) rose by 55.72% and 19.94%, respectively, while the CHTC between air and rear-row PV panels (h_pva2) reduced. When the installation height of PV panel increase, the h_pva1 doubled and h_pva2 rose by 18.97%, whereas heat exchange between the roof and PV panels (h_rpv) is attenuated. Increasing the array setback distance significantly affected the CHTC of the first-row PV panel, resulting in h_pva1 decreased by 25.04% while h_ra increased by 19.80%. This paper reveals fundamental mechanisms governing CHTC at PV array surface, providing the basis for optimizing power generation efficiency and system layouts.

   7. Energy Performance Evaluation of PV Glazing for Building Application in Different Climate Zones

      Jialong Huang, Jia Liu, Huijun Wu, Zhongjie Pan

      Abstract

      This research assesses energy performance of photovoltaic (PV) glazing and PV vacuum glazing for application in a high-rise building in five major climate zones in China. The annual energy performance of the PV glazing is simulated applied in a high-rise building based on the EnergyPlus and System Advisor Model platform compare with the PV vacuum glazing, single glazing and insulated glazing unit. The net present value is calculated to evaluate the economic performance of the PV glazing applied in different climate. The results show that the energy consumption of the PV vacuum glazing compare with single glazing is decrease by 8.30% in severe cold (Harbin), 10.86% in cold (Beijing), 10.01% in hot summer and cold winter (Shanghai), 12.52% in hot summer and warm winter (Guangzhou) and 12.05% in moderate climate (Kunming), respectively. The air-conditioning energy consumption of the PV glazing and the PV vacuum glazing is decreased by 26.7% to 32.35% compare with the single glazing. The annual power generation of the PV glazing is 1225.47 MWh in Harbin, 1203.93 MWh in Beijing, 1005.82 MWh in Shanghai, 894.73 MWh in Guangzhou and 1077.38 MWh in Kunming, respectively. The net present value of the 25-year service life of the PV glazing is -0.34 million CNY in Harbin, -0.69 million CNY in Beijing, -3.43 million CNY in Shanghai, -4.91 million CNY in Guangzhou and -2.60 million CNY in Kunming, respectively. This research can provide guidance for optimizing key configuration parameters of the PV glazing to improve the energy performance in different climate.

   8. Research and Optimization of Numerical Simulation for Cold Water Phase Change Heat Exchanger

      Yuchao Ma, Ying Xu, Meng Liu, Shuang Zhang, Tianyu Zhang

      Abstract

      Firstly, through theoretical analysis, it is concluded that ice thickness is mainly related to cold water velocity, it is found that the inlet temperature of cold water has little influence on the total heat transfer coefficient and icing condition within the experimental range, while the inlet flow of cold water has a greater influence on the ice sheet, and the growth rate of the ice sheet accelerates with the increase of the discharge. Finally, the optimal heat transfer efficiency condition within the experimental range is obtained through numerical simulation, and the analysis shows that the influence of cold water inlet flow on the ice sheet is significantly greater than that of the inlet water temperature, and the decrease of both will lead to the increase of the overall thickness of the ice sheet, but the decrease of the flow will increase the growth rate of the ice sheet. The study of phase changer heat exchanger not only lays a foundation for optimizing the deicing device, but also for improving the heat transfer efficiency of phase changer heat pump system.

   9. Comparative Analysis of Heat Transfer Performance of Energy Segment Connections

      Jinfang He, Xiangyu Guo, Silin Zheng, Ran Ye, Yongming Ji, Songtao Hu

      Abstract

      With the rapid advancement of urbanization and societal development, the demand for energy has surged. A significant amount of waste heat is generated during subway operations. Currently, many projects employ subway-source heat pump technology to absorb this waste heat for heating and cooling above-ground buildings. By integrating heat exchangers with tunnel structures, energy shield segments are formed, achieving efficient waste heat utilization. However, the optimal design configuration of these energy segments remains an area requiring further investigation. This study utilizes COMSOL Multiphysics software to simulate and analyze the heat transfer performance of energy segments under various connection modes, considering different inlet water temperatures and velocities during both heating and cooling seasons.

      The results indicate that all connection modes exhibit excellent heat transfer performance. Specifically, in the heating season, the tandem segment achieves a CHE (capillary heat exchanger) heat transfer rate of 545.15 W, while the parallel segment reaches 563.18 W. During the cooling season, the respective heat transfer rates are 657.21 W and 711.77 W. The parallel segment demonstrates superior heat transfer performance compared to the tandem segment in both seasons. Simulation outcomes confirm that energy segments possess outstanding heat transfer capabilities and can effectively absorb waste heat within tunnels. For practical applications, parallel segments offer enhanced heat transfer capacity, whereas series segments have minimal impact on the internal tunnel structure. This research provides a theoretical foundation for the implementation of metro-source heat pump systems in engineering projects.

   10. Obtaining Thermal Conductivity of Medium-Deep Geothermal Boreholes: A Hybrid Modelling Based on Geological Test

       Yuelong Yu, Shihao Dong, Long Ni

       Abstract

       Medium-deep ground source heat pumps are an important low-carbon heating technology. This study proposes a hybrid thermal conductivity model based on kilometer-scale formation variations. Well logging at a factory site in Shenyang, China, revealed that the upper 0–750 m is Cenozoic strata with higher porosity and argillaceous content, while the underlying Archean formation consists of dense, highly conductive rocks. Permeability is low in deep formations, indicating few aquifers. Borehole No.02, with the lowest porosity and argillaceous content, shows the highest thermal conductivity (2.64 W/(m·K)). Overall, the results highlight the strong influence of geological properties on the thermal performance of medium-deep borehole heat exchangers.

   11. Numerical Comparative Study and Evaluation of Flow Rate for Medium-Depth Coaxial and U-Type Borehole

       Yaru Wang, Shihao Dong, Long Ni

       Abstract

       Coaxial (CBHE) and U-type borehole heat exchangers (UBHE) are two key configurations for medium-deep geothermal energy utilization, yet systematic performance comparisons remain limited. This study develops numerical models for both systems to evaluate their thermal performance. A net heat exchange intensity metric (q), incorporating heat transfer, heat pump efficiency, and pumping power, is proposed for comprehensive system assessment. Results show that both q and the optimal flow rate increase linearly with depth. For CBHE, the optimal flow rates are 15.0 m³/h (1000 m), 17.0 m³/h (1500 m), 19.0 m³/h (2000 m), 21.0 m³/h (2500 m), and 22.5 m³/h (3000 m). At 2500 m depth, CBHEs reach peak q at lower flow rates than UBHEs, but UBHEs outperform CBHEs beyond critical flow rates of 33.0 m³/h (Shenyang) and 29.0 m³/h (Xi’an) due to lower pumping penalties. Correlation analysis identifies thermal conductivity and geothermal gradient as dominant factors affecting optimal flow rate, highlighting the need for site-specific design tailored to geological conditions and exchanger type.

   12. Field Test and Techno-Economic Analysis of a Medium–Deep Ground Source Heat Pump System in a Low-Energy Office Building

       Yong Zhang, Bo Ma, Wei Chen, Xingdan Wang, Xujun Gao, Yongzhi Lei, Anfan Shang

       Abstract

       Ground source heat pumps (GSHPs) provide a clean heating solution, but their application in severe cold regions is limited by low energy efficiency, excessive borehole length, and soil thermal imbalance. Medium-deep geothermal systems offer a promising alternative by utilizing higher subsurface temperatures. However, research on coaxial borehole heat exchanger (CBHE) performance in severe cold regions remains limited, especially regarding techno-economic analysis for low-energy office buildings and comprehensive evaluation methods incorporating subsidies and comparisons with district heating. This study investigates a medium-deep CBHE system in Harbin, China, through field testing and economic analysis using both static and dynamic payback periods. Results show that the system maintained a stable indoor temperature of 21.72 °C when outdoor temperatures ranged from −25.1 °C to −4.2 °C. The maximum source-side COP and heat pump COP reached 6.89 and 6.14, respectively. Heat extraction increased by 8.34 W/m for every additional 100 m of borehole depth, indicating deeper wells are more cost-effective than adding more boreholes. The initial investment was 211 CNY/m², and annual operating costs were 20.21 CNY/m². Without subsidies, economic competitiveness is limited; however, with grid-connection subsidies, the dynamic payback period is 8.4 years, demonstrating favorable economic potential. These findings offer theoretical and practical guidance for optimizing geothermal heating systems in severe cold regions.

   13. Study on the Soil Temperature Variation Characteristics of Stratified Soil Temperature Control and Heat Storage System for Greenhouses in Northeast China

       Jianan Duan, Songqing Wang

       Abstract

       The stratified soil temperature control and heat storage system is carried out for greenhouses in Northeast China, increasing the temperature of plant root zone and storing heat in the soil. The effects of root water absorption and irrigation are considered to analyze the variation characteristics of the soil temperature quantitatively in complex dynamic heat transfer mechanisms, and the root zone temperature is also used as an evaluation criterion to explore the effect of soil temperature on plant growth during the continuous system operation. The results illustrate that the soil temperature is measured to increase significantly. The soil temperatures of the temperature-controlled zone are maintained in the optimal range for plant growth throughout the T2 phase from 15 to 30 days. And the temperature distribution is developed to be spatially uniform as the temperature difference of each position is less than 2%. These results are demonstrated to be effective in fulfilling the developmental requirements of cultivated plants.

   14. Enhanced Thermal Efficiency of Borehole Heat Exchanger with Microencapsulated Phase Change Backfill Materials

       Lingling Xu, Qianbing Li, Haonan Li

       Abstract

       Soil thermal imbalance in borehole heat exchangers (BHE) severely constrains the efficiency of the ground source heat pump system (GSHP), while traditional phase change backfill material is prone to leakage and soil contamination. Based on this, a novel enhanced backfill material - microencapsulated phase change material (MPCM) is proposed in this paper. A three-dimensional model of BHE backfilled with ordinary grout and MPCM is developed and validated against experimental data. Effects of backfill material on thermal performance of BHE and system efficiency are investigated. The results reveal that incorporating MPCM into backfill soil can significantly enhance system performance. Compared with ordinary grouting, the MPCM-enhanced BHE can achieve 6 times increase in heat transfer rate and 15.8% improvement in coefficient of performance (COP). This enhancement is mainly attributed to the large latent heat release. Moreover, MPCM backfill reduces the thermal influence radius of soil temperature by 25%, alleviating the long-term soil thermal imbalance. This study provides new insights into the optimization of BHE and mitigating soil thermal imbalance, which offers practical guidance for the design and deployment of advanced geothermal systems.

   15. Effect of Shape-Stabilize Phase Change Backfill Material (SSPCBM) on Thermal Performance of Borehole Heat Exchanger in the Layered Geological Structure

       Changxing Zhang, Ruishuo Nie, Chong Xu, Sheng Li, Xuezheng Tian

       Abstract

       Lower borehole thermal resistance and higher heat exchange capacity are essential for enhancing BHE thermal performance in GCHP systems. The effects of different shape-stabilized phase change backfill materials (SSPCBM) on BHE performance were investigated under layered geological conditions. Numerical simulations were conducted to assess various SSPCBM deployment cases. A full SSPCBM application (b-b-b-b case) was found to reduce borehole thermal resistance by 44.37% and increase maximum dynamic heat flux by 76.6%, compared to conventional backfill. Significant variation in heat exchange improvement was observed among cases. Partial application near the inlet (a-b-a-a case) yielded a 28.1% improvement, attributed to higher fluid temperatures in the corresponding U-tube section. Phase change behavior of SSPCBM was analyzed under stratified subsurface conditions, revealing that transition rates were strongly influenced by soil thermal properties. Slower phase change was observed in Soil 3 than Soil 4, despite higher fluid temperatures. Spatial deployment effects showed that SSPCBM placement in high-conductivity layers (a-a-b-a case) caused an 18.44% reduction in thermal resistance, while placement in low-conductivity distal layers (a-a-a-b case) resulted in only a 9.92% reduction.

       These findings highlight that the optimal SSPCBM deployment is determined by both local thermal conductivity and fluid temperature distribution, offering practical guidance for its application in layered geological conditions.

   16. Study on the Flow and Heat Transfer Characteristics of Pillow Plate Sewage Heat Exchanger

       Wei Chen, Bo Ma, Yanbin Li, Xuan Liu, Wenbin Han, Mohong Wang, Chao Shen

       Abstract

       The development and utilization of renewable energy are critical for reducing fossil fuel consumption, mitigating environmental pollution, and controlling carbon emissions. Heat pump technology, which applied to low-grade renewable energy, is regarded as a strategic and practical approach to significantly minimize the exergy losses. To meet the economic, environmental, and energy-saving demands, urban wastewater serves as a promising low-grade heat source for heat pumps due to its abundant and temperature-stable properties. However, challenges persist in enhancing heat transfer and preventing fouling. This paper investigates the heat transfer performance of a pillow plate heat exchanger in a wastewater-source heat pump system. Results show that wastewater temperature significantly impacts heat transfer more than flow rate. Compared to traditional immersion exchangers, the pillow plate exchanger exhibits superior performance, higher heat transfer capacity, and COP, and more significant energy savings at higher temperatures. Increased wastewater flow enhances turbulence, further boosting heat transfer, COP, and energy efficiency.

   17. Analysis and Optimization of Flow and Heat Transfer Characteristics of Twisted Oval Tube Shell-and-Tube Heat Exchangers Based on Numerical Simulation

       Zhu Xuwei, Zheng Changjin, Hu Yilin, Cheng Yuanda

       Abstract

       The heat transfer and flow characteristics of twisted oval tube shell-and-tube heat exchangers with baffles (T-STHE-B) were numerically investigated and optimized by the computational fluid dynamics simulations combined with an integrated entropy weight-grey relational-Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) in this research. The impacts of the twisted oval tube structural parameters: short-to-long axis ratio (B/A) and twisted pitch length (P) as well as operating parameters shell side mass flow (m) on shell side heat transfer coefficient (h) and pressure drop (ΔP), were investigated. The results indicated that increasing B/A significantly reduced h, particularly at low m and smaller P, with a maximum reduction of approximately 25.7%. However, at larger pitch lengths, this reduction weakened notably to around 8.7%. An increase in B/A led to a notable rise in ΔP, ranging between 10.8% and 21.8%. With the influence becoming more pronounced at larger P. The two-way ANOVA showed that P and B/A had significant effects on h and ΔP. The F-value for B/A on ΔP was as high as 96.55. This study elucidates underlying mechanisms governing the performance of T-STHE-B and provides a robust methodological framework for parameter optimization.

   18. A Review of Low-Temperature Waste Heat Recovery Technologies in the Steel Industry

       Yifan Cui, Qingwen Xue

       Abstract

       In the steelmaking process, approximately 30% of low-grade waste heat in the iron and steel industry remains unrecovered. Due to its low exergy value and complex heat source characteristics, low-grade waste heat is difficult to utilize. This study first analyzed waste heat distribution patterns across typical blast furnace and converter processes. Then, key technical approaches were then critically reviewed, encompassing waste heat recovery systems, waste-heat-driven power generation technologies. Finally, we proposed two pivotal technologies essential for systematic waste heat valorization: 1) Exergy-driven system optimization methodologies for enhanced thermal cascading; 2) Integrated operational scheduling frameworks accounting for waste heat uncertainties. Addressing these critical challenges will advance low-temperature waste heat utilization, facilitating the steel industry’s transition toward energy-efficient and low-carbon operations.

   19. Research on the Application Potential of Solar Energy and Sustainability of District Energy in Severe Cold Region

       Bingxin Xu, Haoran Ning, Zeguo Qiu, Xiaozhuang Yang, Jianfeng Qian, Boxin Dou, Delin Gu, Ying Wang

       Abstract

       Energy is an important support for urban development and plays a key role in promoting sustainable economic growth. This study takes Heilongjiang Province as an example and combines the GIS geographic information system to conduct a research on solar energy resources in 13 major cities, with the aim of providing a reference for the planning of low-carbon development in the Heilongjiang region. Through regression analysis, it was found that the correlation coefficient. Except for Harbin, the regional economic development level of other cities shows a strong correlation with the potential of solar energy resources. Fitting the GDP of each industry and the utilization rate of solar energy yields, and the GDP of the tertiary industry has a greater impact on the utilization of solar energy. In conclusion, resource endowment is the key driving force for development efficiency. Especially for the differentiated development status of different resource regions, in-depth analysis should be conducted in combination with factors such as policies and geography.

   20. Experimental Study on the Heating of Submarine Tunnel Seepage Seawater Source Heat Pump System

       XinJie Wang, HuiLi Yu, WenJie Dong

       Abstract

       This study addresses the issue of energy waste caused by the direct discharge of seepage seawater from the drainage-type underwater tunnel constructed by the mining method, without effective utilization. The tunnel seepage seawater is utilized as a renewable heat and cold source, and a seawater-source heat pump system is proposed to provide heating (cooling) to adjacent buildings. The performance of the heat pump system was continuously monitored during the heating season, and the actual operational efficiency of the system was analyzed. The measured data shows that under winter heating conditions, the average room temperature in a typical month was 22.4 °C, fully meeting the design requirements. The energy consumption of the distribution system accounted for only 19% of the total system energy consumption, demonstrating excellent energy efficiency characteristics. Notably, the coefficient of performance (COP) of the heat pump unit in a typical month reached 3.6, fully verifying the feasibility and high efficiency of this technological solution in actual engineering applications.

   21. Optimal Flexible Heating Scheduling of Air Source Heat Pumps for Residential Buildings: Application Performance in China’s New Power System

       Xintian Li, Wei Wang, Yuying Sun, Jianhang Song, Shulun han, Jianfei Zhang, Wenzhe Wei

       Abstract

       To enhance the flexibility of residential air source heat pump (ASHP) systems and support their integration into China’s new power system, this study proposes an optimal flexible heating dispatch (OFHS) method and assesses the flexible heating potential of the new power system. The approach optimizes ASHP supply water temperature setpoints in response to time-of-use (TOU) electricity tariffs, leveraging the passive thermal storage capacity of residential buildings and accounting for variations in ASHP coefficient of performance (COP). A dynamic thermal model based on a resistance-capacitance (RC) network is developed to predict indoor air and return water temperatures, enabling proactive scheduling of heating demand. The OFHS method was tested on an ASHP–radiant floor system in a rural household. Results show that the OFHS control method accurately adjusts the set value of the ASHP water supply temperature while ensuring indoor thermal comfort. Compared with the existing control methods, the COP is increased by 6.34% and the heating power consumption is reduced by 7.16%. Meanwhile, the OFHS method can significantly enhance the demand response effect of the ASHP system in residential buildings in the new power system, increasing the power load transfer capacity by 37.01% and reducing the heating operation cost by 22.37%.

   22. Research on Multi-Energy Complementary Heating Systems for Highway Service Area Buildings in Severe Cold Regions

       Haoran Ning, Jianhang Wang, Zeguo Qiu, Jianfeng Qian, Zexuan Wang, Bin Zhong

       Abstract

       Under the “dual-carbon” strategic background, to address the heating challenges of highway service area buildings in severe cold regions beyond urban centralized heating networks and promote the application of multi-energy complementary heating technologies integrating GSHP (Ground-Source Heat Pump), solar energy, and electric thermal storage boilers, this paper analyzes the system design and operational performance of project implementation. It explores fundamental approaches for constructing heating systems in highway service area buildings within this regional context. Selecting a case study of a 7,000 m² highway service area building, five distinct heating schemes were designed with ground-source heat pumps assuming 80%, 75%, 70%, 65%, and 60% of thermal load respectively, aiming to determine the optimal thermal source allocation strategy. Through TRNSYS transient simulation analysis, comprehensive evaluations were conducted on solar collector performance, system COP, water supply temperature stability, and soil thermal balance characteristics across different schemes. Results demonstrate that the optimal configuration occurs when the ground-source heat pump undertakes 65% of the thermal load. This study provides valuable references for future engineering projects with similar requirements.