A novel thermal storage strategy for CCHP system based on energy demands and state of storage tank

Abstract

Under the thermal storage strategies in present studies, the power generation unit (PGU) in combined cooling, heating, and power (CCHP) system is turned on/off only based on the state of storage tank; or the operation state of PGU is determined by thermal demand or/and electric demand, which has no relationship with the state of storage tank. For these traditional strategies, either energy demands or state of storage tank is considered for the operation of system. This paper proposes a novel thermal storage strategy (TSS2) for CCHP systems, which determines the operational state of the PGU based upon electric demand, thermal demand and the state of thermal storage device. In this paper, the operation principle of TSS2 is described and compared with the traditional strategies. A hospital in Shanghai was used to evaluate and compared the performance of the system operating under different storage strategies. The results show that TSS2 improves the performance of CCHP system more significantly compared with the traditional strategies. TSS2 can make both PGU and capacity of thermal storage tank be fully used by CCHP system to produce more electric and thermal energy to meet demands of building. Compared with system without thermal storage, the minimum and maximum increase rates of annual total cost saving for traditional strategies are 0% and 14.84%, respectively. However, for TSS2, they can reach 3.79% and 20.22%. Similar conclusions could be achieved for CO2 emission reduction and primary energy saving. The effect of TSS2 on the CCHP system performance is different under different operation strategies.

Collaborative Optimization of Multi-Energy Complementary Combined Cooling, Heating, and Power Systems Considering Schedulable Loads

“…Zheng et al proposed a new thermal storage strategy (TSS), which determined the operating state of the PGU according to the power demand, thermal demand, and state of the thermal storage device. Results show that the TSS improves the performance of CCHP systems compared to traditional strategies [25]. Kuang et al proposed a dynamic optimization method for CCHP systems with energy storage, and obtained the most economical operation scheme in a very short time by adopting a dynamic solution framework [26].…”

A Day-Ahead Optimal Economic Dispatch Schedule for Building CCHP System Based on Centralized Energy Storage Infrastructure

“…In [9], energy level and exergy analysis are implemented on energy conversion processes to reveal the variation of energy amount and quality in the operation of CCHP system. Zheng C Y et al [10] proposed a thermal storage strategy for CCHP systems to determine the operational state of the power generation unit based upon electric demand, thermal demand and the state of thermal storage device.…”

Dynamic programming for optimal operation of a biofuel micro CHP-HES system

“…performance when energy demands fluctuate. It is believed that a CHP combined with an energy storage system could improve dynamic performance, with [4,5] demonstrating an increase in performance. A similar conclusion was pointed out in [6][7][8] and the work also emphasized that energy management strategies are the key factor in actual operation.…”