Current situation and future trend of geothermal energy development and utilization in China

Bathing and travel vacation. The use of geothermal water for bathing, almost throughout the provinces (districts, cities). According to incomplete statistics, more than 200 hot spring geothermal water sanatoriums have been built across the country, and 430 hot spring baths have been highlighted for medical use. Many hot springs in China are both health resorts and tourism areas. Some hot springs and boiling springs in South Tibet, west Yunnan, west Sichuan and Taiwan not only have high energy geothermal resources, but also have colorful geothermal landscapes, which attract the attention of the world. For example, Tengchong in Yunnan Province is the only well-preserved volcanic hot spring area in China, with rare volcanic and geothermal landscape and precious medical mineral water value; The Datun Volcanic hot spring area in Taiwan Province is also a hot spring spa and tourist attraction.

Farm. Beijing, Tianjin, Fujian, Guangdong and other places started earlier, and now there are 47 geothermal fields in more than 20 provinces (autonomous regions and municipalities). The main breeding tilapia, eel, turtle, green shrimp, bullfrog, ornamental fish, and fish fry winter. Due to the rapid development of hot spring aquaculture, fresh fish sell well at home and abroad, and achieve remarkable economic benefits. In addition, there are geothermal incubation birds, geothermal drying vegetables, geothermal hot water heating biogas digester and livestock bathing pool, etc., also achieved good results.

Agricultural greenhouse planting and irrigation. Geothermal energy is a compound resource, which is very suitable for off-season and off-site breeding and planting of organisms. Geothermal energy can be used to heat greenhouses, geothermal water can be used for temperate aquatic organisms, and the minerals in geothermal water can also provide nutrients for organisms. In the north of China, geothermal is mainly used for planting high-grade melons and fruits, vegetables, edible fungi, flowers, etc., in the south, mainly used for seedling cultivation.

Industrial production. At present, it is mainly used for textile printing and dyeing, washing, tanning, paper making, wood and grain drying, etc., among which the underground hot water in the hot spring area has obtained better utilization and benefits in the textile industry and chemical industry. At the same time, some geothermal water can also extract industrial raw materials, such as the Tengchong Rehai sulfur pond by panning method to obtain sulfur, Eryuan County Jiutai hot spring area to dig salt salt and natural sulfur, Taiwan since the Ming and Qing Dynasties have been in the Datun volcanic hot spring area of natural sulfur mining.

High temperature geothermal power generation. In terms of geothermal power generation, in the early 1970s, China developed medium-low temperature geothermal energy in Jiangxi, Guangdong and other places, and built a number of geothermal demonstration power stations. In 1977, China began to develop medium-high temperature geothermal energy, and the first medium-high temperature geothermal power generation demonstration station was built in Yangbajing, Xizang Province. Since then, the Yangbajing geothermal Power Station has built seven 3MW units and one 3.18 imported unit in 14 years, which will continue to operate until 2020. In September 2018, the 16MW dual-medium geothermal power generation unit of Yangyidi Thermal Power Station was connected to the grid for the first time, and it was normally operated in 2019, becoming the largest single power geothermal power unit in China so far.

Although the scale of high-temperature geothermal power generation in China lags behind the world, the ground equipment technology of high-temperature geothermal power generation has always followed, mainly because some steel mills, chemical plants and other high-temperature waste heat resources need to be utilized, so it has been developing from the perspective of waste heat power generation.

According to the different principles of ground power generation equipment, high-temperature geothermal power generation is generally divided into several categories: single-pole flash geothermal power generation technology, bipolar flash geothermal power generation technology, dual-medium power generation technology, full-flow power generation technology (that is, screw expansion engine technology), and dual-medium power generation technology is the most widely used. Among the high temperature geothermal power generation technology, the surface power generation equipment technology has a variety of solutions, and the technology is relatively mature. The most difficult technology is the exploration technology of high temperature geothermal resources. How to explore high temperature geothermal resources and how to bring underground high temperature geothermal resources to the surface is a difficult technology. High-temperature geothermal power generation is relatively easy to achieve if high-temperature geothermal fluids can be extracted from the ground.

"Geothermal energy +" multi-energy complementary. The "geothermal +" green storm characterized by "multi-energy complementarities and intelligent coupling" is quietly forming everywhere. "Geothermal energy +" a variety of clean energy complementary heating technology, innovative design of geothermal cascade utilization process, geothermal high temperature part for power generation, low temperature part for heating, improve geothermal utilization. Demonstration bases for the development and utilization of second-level geothermal energy cascades for power generation and heating have been initially established in the Beijing-Tianjin-Hebei region and southeast coastal areas.