Optimized Configuration Plan for Cooling and Heating Source Systems
The cooling and heating source system accounts for the largest share of hotel MEP energy consumption (approximately 40%-50%), with enormous optimization potential. Based on the framework requirements of GB 50736 and GB 50189, cooling and heating source optimization can be developed from the following dimensions: First, heat pump coupling scheme—a hybrid scheme of ground-source heat pump + chiller uses borehole heat exchangers as auxiliary heat dissipation devices; in summer, the low soil temperature is used to pre-cool cooling water, increasing COP by approximately 8%-12%. Second, cooling and heat recovery linkage scheme—install heat recovery chillers to recover condensing heat while cooling to prepare domestic hot water, improving comprehensive energy efficiency by 15%-20%. Third, cool storage optimization scheme—utilize peak-valley electricity price differentials to store cooling at night and release it during the day; when the peak-valley price ratio exceeds 3:1, the investment payback period is approximately 3-5 years. Fourth, multi-compressor unit and unit quantity control optimization—configure 3-4 chillers of different capacities (e.g., 40%+30%+30%) and select the optimal operating combination through intelligent group control. Fifth, large temperature differential scheme—chilled water adopts a 6/13℃ temperature differential (7℃) instead of the traditional 5℃ temperature differential, reducing pump energy consumption by approximately 28%-30%.
Air-conditioning Terminal System Optimization and Airflow Organization
Air-conditioning terminal system optimization directly affects guest room comfort and operating energy consumption. Based on GB 50736 Section 8.4 and ASHRAE 55-2021, terminal optimization can be developed from the following aspects: First, guest room FCU selection optimization—adopt variable-frequency EC motor FCUs that automatically adjust speed according to load changes, with an energy-saving rate of 30%-50%. Second, airflow organization optimization—guest room air supply is recommended as side supply with upper return or ceiling supply with ceiling return, avoiding direct blowing toward the head of the bed; use swirl diffusers to enhance the Coanda effect and ensure temperature uniformity with a temperature difference not exceeding 1.5℃. Third, decentralized fresh air handling scheme—set up small primary air handling units (PAU) on each floor to shorten fresh air duct length, reduce duct resistance and cooling loss; the sensible heat efficiency of the heat recovery device shall not be less than 65%. Fourth, energy-saving temperature control strategy—automatically switch to energy-saving mode when the guest room is unoccupied, with a temperature setpoint offset of 3-4℃, reducing guest room air-conditioning energy consumption by approximately 18%-25%. Fifth, zoned refined management—divide into perimeter zone (near windows), interior zone (no external windows), and special zones (kitchen, swimming pool), each with independent air-conditioning systems.
Electrical System Optimization and Energy-Saving Practices
Electrical system optimization covers the coordination of three subsystems: power supply and distribution, lighting, and intelligent systems. Based on the frameworks of GB 50052, GB 50034, and GB 51348, optimization measures include: First, distribution center optimization—place transformer and distribution rooms as close as possible to the load center, shorten low-voltage distribution cable lengths, and reduce line losses; the power supply radius should not exceed 250 m. Second, transformer economic operation—two transformers serve as mutual backup; during low-load periods, one transformer is shut down to raise the load rate to the economical operating range of 60%-80%. Third, lighting system optimization—full LED lighting combined with intelligent dimming control systems; LPD target values: guest rooms not exceeding 7 W/m2, lobby not exceeding 11 W/m2, banquet hall not exceeding 18 W/m2. Using LED lighting can reduce LPD by approximately 35%-40%. Fourth, power factor compensation—install centralized automatic reactive power compensation devices to compensate the power factor to above 0.95. Fifth, intelligent power distribution system—adopt intelligent distribution cabinets and EMS to monitor energy consumption data of each circuit in real time and automatically identify abnormal energy consumption warnings.
Water Supply and Drainage System Water Conservation and Energy Efficiency Optimization
The focus of water supply and drainage system optimization is water conservation, hot water energy saving, and improved drainage reliability. Based on the requirements of GB 50015 and GB 50974, optimization schemes include: First, variable-frequency constant-pressure water supply—adopt a combination of variable-frequency pumps + pressure tanks, saving approximately 25%-35% energy compared with the elevated water tank scheme. Second, hot water system optimization—install solar collectors or air-source heat pumps as hot water preheating devices to reduce boiler gas consumption; variable-frequency control of hot water circulation pumps saves approximately 30% energy. Third, water-saving fixture selection—Grade 1 water efficiency toilets (not exceeding 4.0 L/flush) and faucets (not exceeding 6.0 L/min) are fully adopted, reducing total water consumption by 20%-25%. Fourth, rainwater harvesting and reclaimed water reuse—in accordance with GB/T 50378 requirements, set up rainwater collection tanks to collect roof rainwater for green irrigation and landscape water replenishment, replacing 10%-15% of municipal water. Fifth, drainage system optimization—adopt separate sewage and wastewater systems to avoid excessive septic tank loading.