Natural gas vehicle filling device

According to the characteristics of the regional energy system, the demand forecast of air conditioning cooling and heating load and domestic hot water load in Beijing Lize Financial Business District was carried out, and the multi-energy complementary energy utilization technology was proposed. The construction ideas of the energy system of the project were introduced, which provided preliminary exploration for further deepening of regional energy planning in the future.

Energy is the material basis for economic and social development and the basic guarantee for the normal operation of urban regional functions. Building a safe, efficient and flexible energy supply system will coordinate the construction and development of energy with the goals of regional economic and social development, providing a solid energy foundation for the rapid development of the region.

Taking the multi-energy complementary energy system project of Beijing Lize Financial Business District as an example, starting from energy demand forecasting, renewable energy utilization, regional cooling and heating, etc., this paper specifically introduces the construction ideas of the project's energy system, and conducts preliminary exploration for further deepening of regional energy planning in the future.

Project Overview

Beijing Lize Financial Business District (hereinafter referred to as the "Business District") is an emerging financial functional area that Beijing and Fengtai District have focused on developing. It has a relatively superior geographical location, convenient transportation conditions and concentrated land resources that can be developed and utilized, providing a new carrying space for the sustainable development of the capital's financial industry. The planning scope of the Business District is based on Lize Road, starting from Caihuying Bridge in the east, west of Lize Bridge in the west, Fengcaohe North Road in the south, and Honglian South Road in the north, with a total planned land area of about 8.09 square kilometers. Among them, the business core area starts from the edge of the construction land in the central area in the west, the Beijing-Kowloon Railway in the east, the planned Nanma Lian Road in the north, and the planned Jinzhongdu North Road in the south, with a total land area of about 2.81 square kilometers. Figure 1 is the overall planning map of the Lize Business District.

Energy Demand Forecasting

1) Current load

At present, most of the existing buildings in the business district are heated by natural gas boiler rooms. The existing building area is 225,300 square meters, of which the existing residential building area is 155,300 square meters and the educational and scientific research building area is 70,000 square meters. The total heat load is estimated by the heat load index method to be 9712kW. Since the existing buildings are heated by clean energy, the energy demand forecast range focuses on the newly planned buildings. 

2) Air conditioning cooling and heating load 

The estimation of air conditioning cooling and heating load needs to be determined based on multiple factors such as building function, personnel density, work and rest time, lighting equipment, etc. Therefore, the index method is used to estimate the air conditioning cooling and heating load of buildings in the area. The planned business district is a financial business district integrating commerce, catering, schools, hospitals, star-rated hotels, and offices. Among them, there are banks, data centers, 24h computer rooms and other users who use cold water all year round. At the same time, hotels and high-end apartments have a demand for domestic hot water supply. The selection of heating indicators for this project is based on CJJ34-2010 "Urban Heating Pipeline Network Design Code" and DB11/687-2015 "Beijing Public Building Energy Saving Design Standard", and refers to the business district control planning indicators, low-carbon ecological construction indicators, and load estimation indicators, as shown in Table 1.

For the simultaneous use coefficient, public buildings are considered to be equipped with centralized air conditioning systems, and the simultaneous use coefficient is 0.5~0.8 according to different building types. According to the recommended heating index in Table 1, the newly planned total heating area within the research scope of this project is 5.3642 million square meters, and the newly planned total heating load is about 418MW; the newly planned total cooling area is 4.8544 million square meters, and the newly planned total cooling load is about 377MW. 

3) Domestic hot water load 

Domestic hot water index is based on the requirements of GB 50015-2015 "Design Code for Building Water Supply and Drainage". By using the index method to estimate, the domestic hot water heating load in summer is 23.3MW. The domestic hot water supply and return water temperature in summer is 120/60 degrees:. The domestic hot water supply in summer relies on the driving heat source of the lithium bromide absorption refrigeration unit of the energy station, and the water supply temperature is 120 degrees. The estimated value of the domestic hot water index is shown in Table 2.

Energy Utilization Technology

In order to realize the green and low-carbon nature of the entire business district, an innovative smart clean energy system is adopted in energy management. By adopting the "1+4+N"+X construction model, the smart clean energy system achieves a "one-stop" service of unified planning, unified construction and unified management of "sources", "networks" and "stations". The energy system planned according to this plan will merge the cooling pipelines and heating pipelines, realize the same network and the same ditch for the cold and hot pipelines, use the hot and cold switching technology, rely on the intelligent management and control platform, and realize the "road surface" in the setting of inspection wells and maintenance channels. The construction goals are “no manhole covers, no road damage for maintenance, and no road occupation for maintenance”. The scale of the pipe network is considered as a whole based on the different cooling and heating loads in winter and summer, which saves underground municipal resources, improves the security of energy supply, and meets the individual needs of users.

The centralized cooling system mainly uses the summer waste heat refrigeration of Caoqiao Thermal Power Plant of Southwest Thermal Power Center, combined with electric refrigeration and ice-cooling to build a composite regional centralized cooling system. The project will build 4 new energy stations and install 10 8MW bromide absorption units. Type hot and cold water units, 4 7MW centrifugal chillers, 22 9.5MW dual-mode main engines and ice storage equipment and other supporting facilities. Two thermal heat exchange stations are set up in the north and south areas of the heating pipe network project, with approximately 7921m of pipelines laid. At the same time, supplementary energy includes multiple distributed energy stations, including trigeneration energy stations, ground source heat pump stations, rooftop photovoltaic power stations, green electricity thermal storage stations, sewage source heat pump stations, etc. This centralized cooling and heating system combines a variety of complementary energy forms to achieve peak shaving and valley filling, which not only improves energy utilization levels and improves the quality of the atmospheric environment, but also achieves 100% clean energy function for the entire Lize Park. Target.

1) The gas-fired cooling, heating and power trigeneration system uses the principle of cooling to determine the installed capacity. The annual stable cooling load of the C-06 plot and the C-07 plot is used as the basic cooling load. Conventional Electric refrigeration performs peak shaving of cooling loads. The cooling loads during the non-heating season and non-peak power periods were sorted out. The maximum design cooling load is 7642kW, the minimum design cooling load is 3908kW, and the total operating time is 3904h. Three 2MW gas-fired internal combustion generator sets and three flue gas and hot water type bromide units are arranged in a one-to-one arrangement. Taking into account the characteristics of the phased implementation of data center cabinets, consider installing them in phases. 

2) Shallow ground source heat pump The shallow ground source heat pump system uses the same hot and cold network planned in the area for supplementation and peak shaving. The ground source heat pump pilot is carried out in the D-07 plot and D-08 plot area to provide services for these two areas. Each plot provides basic cooling and heating loads. Through estimation, the total design cooling load of plots D-07 and D-08 is 10 240kW, the total design heating load is 12 800kW, and the daily hot water load is 382.9kW. According to the principle of ground source heat pump with base load, the base load rate is 51%. Therefore, the designed heating load of the ground source heat pump is 6500kW. The underground double U pipe is Φ32mm and the hole is Φ120mm. The underground pipe hole required for this project If the number is 1,000 and the hole spacing is 5m, the required green space area is 25,000 square meters. The total cooling capacity of the ground source heat pump system is 5184kW. 

3) Sewage source heat pump The sewage source heat pump system uses the same hot and cold network planned in the area to supplement and peak load. The industrial land F10, F11, F12 and F13 in the park are heated by sewage source heat pump. The total designed heating load is 9996.0kW. Three water source heat pump units are selected. The heating capacity of a single unit is 3 400kW, and the designed required sewage volume is 1 228m³/h.

4) Solar Photovoltaic Beijing belongs to the second category of solar energy resources. In this project, the development of photovoltaic power generation projects should mainly consider the construction method of combining distributed photovoltaic power stations and decentralized photovoltaics, that is, using building roofs, exterior walls and other conditions to carry out photovoltaic building integration. Combined with the geographical location and climatic conditions, taking into account the safety and rationality of electricity use, photovoltaic power generation is appropriately adopted. A total of 1 centralized photovoltaic system is set up, and the available roof area is considered to be 90%. 5) Solar Thermal The domestic hot water demand for offices, hotels and apartments in the project area is all solved by solar energy. The auxiliary heating method can be different according to different seasons. In winter, municipal thermal auxiliary heating is used, and in summer, electric auxiliary heating is used. The solar thermal collection system adopts a decentralized type and is installed on the roof of each user. In summary, the technical solutions determined are as follows: 

(1) The solar water heating system adopts a flat-plate solar collector centralized engineering solar water heating system, and the operation mode is a direct current constant temperature water production type. The ground source heat pump is selected as the auxiliary energy of the system; 

(2) The system water supply is a water pump forced circulation method, and an intelligent water control system is set at the end of the water use;

(3) Solar collector panels are installed on available building roofs.

Energy Consumption and Energy Saving Benefits

The business district adopts a multi-energy complementary energy system, realizes the use of a variety of renewable energy and energy-saving technologies, and brings good social benefits.

The distributed energy system is used in the business district to achieve heating in winter and cooling in summer, which improves the efficiency of energy utilization and achieves the green park energy conservation and emission reduction goal of 100% clean energy utilization in the entire business district. Through shallow ground source heat pumps, sewage source heat pumps, solar photovoltaic, solar thermal and other technologies, the utilization of local renewable energy in the business district is realized, and the utilization ratio of renewable energy in the region is increased.

Evaluate

The multi-energy complementary energy system of Beijing Lize Financial Business District organically combines traditional centralized heating with new economical and energy-saving centralized cooling, applies a number of energy-saving technologies, and coordinates the planning, construction, and centralized management of "source, network, and station". This energy supply model is safer, more reliable, greener, and more low-carbon, more economical and energy-saving than traditional energy supply. It complies with the country's energy industry policies and building energy conservation requirements, and will become the country's first green, low-carbon, and smart energy system demonstration project with multi-energy integration, safe and efficient transportation, and intelligent management.