Combined Heat and Power Dispatch Considering Heat Storage of Both Buildings and Pipelines in District Heating System for Wind Power Integration

Quan Lv,Haixia Wang,Weidong Li,Ping Li

doi:10.3390/en10070893

Abstract

The strong coupling between electric power and heat supply highly restricts the electric power generation range of combined heat and power (CHP) units during heating seasons. This makes the system operational flexibility very low, which leads to heavy wind power curtailment, especially in the region with a high percentage of CHP units and abundant wind power energy such as northeastern China. The heat storage capacity of pipelines and buildings of the district heating system (DHS), which already exist in the urban infrastructures, can be exploited to realize the power and heat decoupling without any additional investment. We formulate a combined heat and power dispatch model considering both the pipelines’ dynamic thermal performance (PDTP) and the buildings’ thermal inertia (BTI), abbreviated as the CPB-CHPD model, emphasizing the coordinating operation between the electric power and district heating systems to break the strong coupling without impacting end users’ heat supply quality. Simulation results demonstrate that the proposed CPB-CHPD model has much better synergic benefits than the model considering only PDTP or BTI on wind power integration and total operation cost savings.

Highlights

The installed capacity of wind turbines has been increasing recently in China [1], involving much uncertainty for the electric power system (EPS), which puts forward higher requirements for the system operational flexibility
This paper proposes a combined heat and power dispatch model considering both pipelines’ dynamic thermal performance (PDTP) and buildings’ thermal inertia (BTI) simultaneously (CPB-CHPD model) to reduce wind power curtailment and total operation cost, which meets the electric load and heat load demands, as well as satisfies the EPS and district heating system (DHS) constraints
A simulation for the combined heat and power system shown in Figure 4 is carried out to demonstrate the effect of the proposed model, where the EPS consists of two CHP units, two condensing power (CON)

Summary

Introduction

The installed capacity of wind turbines has been increasing recently in China [1], involving much uncertainty for the electric power system (EPS), which puts forward higher requirements for the system operational flexibility. They did not consider the coordinating effect of both PDTP and BTI in the optimal operation of EPS and DHS for wind power integration To bridge these gaps, this paper proposes a combined heat and power dispatch model considering both PDTP and BTI simultaneously (CPB-CHPD model) to reduce wind power curtailment and total operation cost, which meets the electric load and heat load demands, as well as satisfies the EPS and DHS constraints. This paper proposes a combined heat and power dispatch model considering both PDTP and BTI simultaneously (CPB-CHPD model) to reduce wind power curtailment and total operation cost, which meets the electric load and heat load demands, as well as satisfies the EPS and DHS constraints This approach exploits the coordinating effect of both PDTP and BTI to break the strong linkage of power and heat supply of CHP units more effectively.

System Model of the DHS

Electric and Heat Power Characteristics

Operation Cost

District Heating Pipelines Network

Single Pipeline Level

Pipeline Network Level

Buildings

Relationship between Indoor Temperatures and Heat Power Supplied

Indoor Temperatures Limits

Between Heat Sources and Pipelines Network

Between Pipeline Network and Heat Loads

Optimization Model of the CPB-CHPD