Recovering waste heat steam, hot water, and pressure energy
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This post was last edited by Waste Heat and Pressure Power Generation on 2017-3-11 at 20:05. It is observed that in the chemical industry and other industrial production processes, a large amount of steam and condensed hot water is wasted through cooling or air cooling; now there are excellent methods for recovering this waste, which also yield good economic benefits. The principle of low-temperature waste heat power generation is power generation based on temperature differences or pressure differences. Through an ORC organic Rankine cycle system, the temperature difference between the hot and cold sources is converted into a pressure difference in the working fluid, which drives the expansion engine to perform work and thereby generates electricity. The low-pressure liquid organic working fluid is pressurized by a working fluid pump and then enters the evaporator, where it absorbs heat and transforms into high-temperature, high-pressure vapor. This high-temperature, high-pressure organic vapor then drives an expander to perform work, generating energy output. The low-pressure vapor exiting the expander goes into the condenser, releases heat to a low-temperature heat source, and condenses back into a liquid state, thus repeating this cycle continuously. Cogeneration using low-temperature waste heat requires a low temperature of the heat source, generally below 200°C ； Heat sources can take various forms: such as excess hot water from production processes, low-pressure steam, industrial wastewater, chemical products, industrial flue gases, seawater, geothermal energy, solar thermal energy, and so on ； Cold sources typically make use of existing circulating cooling water systems, or readily available low-temperature substances, such as the cold energy released during the gasification of LNG, liquefied natural gas. The principle of pressure-driven power generation is to use the pressure or pressure energy of process gases to directly drive an expander to generate electricity. The process gas can be water vapor at a certain pressure, CNG compressed natural gas, and the pressure energy of natural gas pipelines, among others. Waste heat and pressure power generation primarily makes use of the waste heat and pressure generated during industrial production processes to generate electricity, thereby achieving the goal of energy conservation and emission reduction.
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Thank you, I hope to get some guidance from all of you in the future
Over the past one or two years, we have completed dozens of steam and hot water recovery projects in China, all of which are now operating stably, generating significant power output while also reducing corporate costs considerably.
This post was last edited by Yu Re Yu Ya Fa Dian on 2016-11-27 at 22:01. The user is involved in the petrochemical industry, as well as in operations related to formaldehyde factories, fertilizer plants, melamine factories, natural gas distribution stations, and waste heat boilers
This post was last edited by Waste Heat and Pressure Power Generation on 2017-3-20 09:10. Steam in quantities of over one kilogram can be used to recover pressure energy for power generation
At a certain natural gas gate station, the pressure in the provincial pipeline network ranges from 3 to 6 MPa; this pressure needs to be reduced to 0.35 MPa using throttling valves. To prevent the pipes from freezing, energy is used for heating the pipes through a water bath. Now, after pressure reduction by the gas expansion unit, over 300 kilowatts of electrical power and over 400 kilowatts of cooling energy are generated simultaneously per hour for ice production.
Since the steam required to drive a turbine must be saturated or superheated steam, and steam scaling has a significant impact on the operation of the turbine, the requirements for the turbine’s operation are also very high. Screw expander generator sets are modern types of generators that can be used both domestically and internationally to utilize low-grade energy sources such as superheated steam, saturated steam, two-phase wet steam, hot water and hot fluids, as well as polluted water with high salt content (such as boiler drain water, geothermal water, and slag washing water from steel plants). Steam with a pressure of 0.1 MPa or more (i.e., 1 kilogram), flue gases with a temperature of 150 degrees or higher, and hot water or hydrothermal fluids with a temperature of 75 degrees or higher (including gas-water mixtures) can all be used. It is particularly suitable for industries such as steel and chemical manufacturing, where production loads experience significant fluctuations and various low-quality heat sources are generated during the production process; it fills the technical gap in China regarding the recovery and utilization of low-temperature waste heat and pressure for power generation.