A heat accumulating steam and hot water cogeneration waste heat boiler system

Abstract

The application discloses a heat-accumulating type steam and hot water cogeneration waste heat boiler system, which comprises a waste heat boiler body, a heat-accumulating type heat medium water system and related control valves. The waste heat boiler can absorb waste heat of flue gas to obtain hot water with different temperatures. Steam generated by vaporization and separation of superheated water in a steam drum can enter a steam pipe network after being heated by a heater to supply high-temperature users. Water with low enthalpy can be output by the heat-accumulating type heat medium water system to supply production and living hot water required by low-temperature users. The hot water is pumped back to the waste heat boiler body by a hot water circulating pump / booster after being cooled, and is heated by low-temperature flue gas, so that the exhaust gas temperature of the waste heat flue gas is further reduced, and the utilization efficiency of the waste heat is improved. The application realizes steam and hot water cogeneration functions of the waste heat boiler, outputs high-quality steam, and outputs high-temperature hot water with required temperature and pressure of users, and has simple control, high stability and high precision, and meets the requirements of fine production and life.

Description

Technical Field

[0001] This invention belongs to the field of industrial waste heat recovery and utilization, and particularly relates to a thermal storage steam-hot water cogeneration waste heat boiler system. Background Technology

[0002] In steel production processes, various furnaces and kilns generate flue gas at different temperatures after burning fuels such as coal gas or natural gas. This flue gas carries a large amount of waste heat. Recovering and utilizing all of this waste heat not only generates significant economic value but also reduces energy waste, aligning with the national requirements for "energy conservation, carbon reduction, and green development" for enterprises. Currently, common methods for recovering this waste heat include reusing waste heat air or coal gas in the original production process, or adding waste heat boilers to generate steam. This steam is typically sent to a steam pipeline network for use in other processes or for power generation with turbines. However, the pressure and temperature losses of this steam sent to the pipeline network increase significantly with the distance it is transported. Generally, the pressure drop in a steam pipeline network is 0.1–0.15 MPa / km, and the temperature drop is about 10℃ / km, with additional condensate loss. The economical heating radius of a steam pipeline network is approximately 2–7 km. In contrast, hot water pipeline networks have a temperature drop of only 1℃ / km compared to steam pipeline networks, offer greater heat storage capacity, gentler temperature changes, no steam-water impact, no condensate loss, and superior heating quality. In recent years, countries around the world have developed high-temperature hot water heating. Because it uses a single heat medium, and a high-temperature heat medium, it can simultaneously meet the heating requirements of production processes and domestic use. my country is also developing a high-temperature hot water heating system with a hot water temperature of 190℃. High-temperature hot water pipe networks not only greatly simplify the pipe network, but also expand the heating range and improve waste heat utilization and economic benefits due to their low temperature loss.

[0003] A waste heat boiler is a general-purpose waste heat recovery device that generates steam at different temperatures and pressures depending on the available waste heat resources, while simultaneously reducing the flue gas temperature to a safe level before discharge. Existing general-purpose waste heat boilers recover waste heat from flue gas to generate steam, but are subject to steam quality requirements, resulting in relatively high exhaust gas temperatures, which are insufficient to meet the demands of today's sophisticated production and daily life. Summary of the Invention

[0004] The technical objective of this invention is to provide a regenerative steam-hot water cogeneration waste heat boiler system to solve the problem of low precision.

[0005] To solve the above problems, the technical solution of the present invention is as follows:

[0006] A regenerative steam-hot water cogeneration waste heat boiler system includes:

[0007] The waste heat boiler body includes a superheater, evaporator, economizer, feedwater preheater, heat medium water heat exchanger, and steam drum.

[0008] One end of the feedwater preheater is connected to the deaerator pipeline to preheat the boiler feedwater entering the deaerator, thereby reducing the steam consumption of the deaerator.

[0009] The economizer is connected to the steam drum and the deaerator at both ends, respectively, and is used to heat the boiler feedwater from the deaerator to a sub-enthalpy state to obtain sub-enthalpy water, which is then fed into the steam drum.

[0010] Both ends of the evaporator are connected to the steam drum pipeline to receive under-enthalpy water, heat it to a superheated state, and vaporize it;

[0011] Steam drums are used to evaporate superheated hot water and separate steam and water to produce saturated steam.

[0012] The superheater is connected to the outlet pipeline of the steam drum and is used to receive saturated steam and further heat it to a superheated state before outputting it to external steam users.

[0013] More preferably, a boiler makeup water / feed water subsystem is also provided, which includes a deaerator, a makeup water pump, a feed water pump, and a desuperheating and pressure reducing valve, used to provide pressure and water source for the boiler to generate qualified steam;

[0014] The deaerator is used to receive saturated steam from the steam drum and to deaerate the boiler feedwater entering the deaerator.

[0015] The makeup water pump is located on the pipeline connecting the external boiler and the feedwater preheater, and is used to pressurize the boiler and send makeup water to the feedwater preheater.

[0016] The feedwater pump is located on the pipeline connecting the deaerator and the economizer, and is used to pressurize the boiler feedwater and send it to the economizer.

[0017] The desuperheating and pressure reducing valve is installed on the pipeline between the deaerator and the steam drum. It is used to desuperheat and reduce the pressure of the received saturated steam before sending it into the deaerator.

[0018] More preferably, a thermal storage heat transfer water subsystem is also provided, including a thermal storage hot water boiler drum, a pressure regulating valve, a temperature regulating valve, and a hot water circulation pump or a hot water booster pump;

[0019] The inlet of the regenerative hot water boiler drum is connected to the heat medium water heat exchanger, and the outlet is connected to the hot water user. It is used to store, regulate, and output the hot water required for production / domestic use. Its operating pressure is lower than that of the steam drum and higher than that of the deaerator.

[0020] The temperature regulating valve is connected to the steam drum at the inlet and to the thermal storage hot water boiler drum at the outlet, and is used to regulate the temperature of the hot water inside the thermal storage hot water boiler drum.

[0021] The pressure regulating valve is connected to the thermal storage hot water boiler drum at the inlet and to the deaerator at the outlet. It is used to release the pressure of hot water that has expanded due to heating and to maintain the pressure stability of the thermal storage heat medium water subsystem.

[0022] Hot water circulation pumps or hot water booster pumps enhance the circulation power of heat medium water in thermal storage heat medium water subsystems.

[0023] Hot water users include ORC generator sets, lithium bromide chiller units, low-temperature multi-effect seawater desalination equipment, and heating and heat exchange systems.

[0024] Specifically, the heat exchanger is used to heat the hot water in the heat storage heat exchanger subsystem, reduce the exhaust temperature of the waste heat flue gas, and improve the utilization efficiency of waste heat.

[0025] This invention adds a regenerative hot water boiler drum, a heat transfer medium water heat exchanger, a pressure regulating valve, and related piping systems to a general waste heat boiler system. The heat transfer medium water heat exchanger can be arranged at any temperature range within the boiler to exchange heat with the flue gas according to the temperature of the waste heat flue gas and the temperature requirements of the hot water users. The regenerative hot water boiler drum is connected to the steam drum and deaerator. The hot water temperature and pressure are stabilized through regulating valves, outputting hot water at the temperature and pressure required by the users. The control is simple, stable, and highly accurate, meeting the needs of today's refined production and living environments. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention.

[0027] Figure 1 This is an embodiment of the thermal storage steam-hot water cogeneration waste heat boiler system of the present invention.

[0028] Explanation of reference numerals in the attached figures

[0029] 101: Waste heat boiler body; 102: Feedwater preheater; 103: Economizer; 104: Evaporator; 105: Superheater; 106: Steam drum; 107: Desuperheating and pressure reducing valve; 108: Deaerator; 201: Heat medium water heat exchanger; 202: Regenerative hot water boiler drum; 203: Temperature regulating valve; 204: Pressure regulating valve; 205: Hot water circulation pump; 206: Closed-loop hot water subsystem. Detailed Implementation

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0031] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0032] The regenerative steam-hot water cogeneration waste heat boiler system proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description and claims.

[0033] Example

[0034] See Figure 1 This embodiment provides a regenerative steam-hot water cogeneration waste heat boiler system. Specifically, the waste heat boiler body 101 includes: a heat medium water heat exchanger 201, a feedwater preheater 102, an economizer 103, a steam drum 106, an evaporator 104, and a superheater 105. The heat medium water heat exchanger 201 is used for heating hot water in the regenerative heat medium water subsystem. The feedwater preheater 102 is used for the waste heat of the boiler's makeup water / feed water subsystem. The two ends of the economizer 103 are connected to the feedwater end of the steam drum 106 and the feedwater subsystem pipeline, respectively, to heat the feedwater to a sub-enthalpy state, and then input the sub-enthalpy water into the steam drum 106. Both ends of the evaporator 104 are connected to the pipeline of the steam drum 106 to receive the sub-enthalpy water and heat it to a superheated state, so that the superheated water evaporates in the steam drum 106 and achieves steam-water separation. The superheater 105 is connected to the outlet pipe of the steam drum 106. The saturated steam is further heated to a superheated state in the superheater 105 and then discharged to the outside.

[0035] The boiler's makeup water / feedwater subsystem is connected to the waste heat boiler body piping and is used to supply water to the waste heat boiler body. Specifically, the makeup water / feedwater subsystem includes a makeup water pump, a deaerator 108, and a desuperheating and pressure reducing valve 107 for the feedwater pump and deaerator. The inlet of the makeup water pump is connected to the external boiler piping, and its outlet is connected to one end of the feedwater preheater 102, pressurizing the external makeup water and outputting it to the feedwater preheater 102. The feedwater preheater 102 heats the pressurized makeup water and outputs it to the inlet of the deaerator 108, where deoxygenation is achieved. The steam used for deoxygenation is introduced into the deaerator from the steam pipe at the outlet of the steam drum 106 via the desuperheating and pressure reducing valve 107. The deaerator 108 then outputs the deoxygenated makeup water from its outlet, which is pressurized by the feedwater pump and output to the economizer 103.

[0036] The thermal storage hot water subsystem can be divided into a hot water circulation pump, a thermal storage hot water boiler drum 202, a temperature regulating valve 203, a pressure regulating valve 204 (pressure relief), a hot water circulation pump 205, and a closed-loop hot water subsystem 206. In the closed-loop hot water subsystem 206, the hot water is heated by the hot water heat exchanger 201 and then enters the thermal storage hot water boiler drum. The thermal storage hot water boiler drum 202 is connected to the temperature regulating valve 203, the pressure regulating valve 204 (pressure relief), the hot water circulation pump 205, and the heat users.

[0037] Preferably, in this embodiment, the operating pressure of the closed-loop hot water subsystem 206 is lower than that of the steam drum 106 and higher than that of the deaerator 108. The volume expansion of the closed-loop hot water subsystem 206 due to heating can discharge the hot water in the thermal storage hot water boiler drum 202 into the deaerator 108 through the pressure relief valve 204. The hot water temperature of the closed-loop hot water subsystem 206 can be adjusted by introducing hot water from the steam drum 108 through the temperature regulating valve 203 to regulate the hot water temperature in the thermal storage hot water boiler drum 202.

[0038] The system in this embodiment is particularly suitable for the recovery of waste heat from industrial furnace flue gas with exhaust gas temperature below 300°C. By applying this subsystem, some high-grade steam can be obtained while the exhaust gas temperature of industrial furnaces can be reduced to an even lower level, thus realizing the cascade utilization of low-temperature waste heat.

[0039] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A regenerative steam-hot water cogeneration waste heat boiler system, characterized in that, include: The waste heat boiler body includes a superheater, an evaporator, an economizer, a feedwater preheater, a heat transfer medium water heat exchanger, and a steam drum. One end of the feedwater preheater is connected to the deaerator pipeline and is used to preheat the boiler feedwater entering the deaerator, thereby reducing the steam consumption of the deaerator. The economizer is connected to the steam drum and the deaerator at both ends, respectively, and is used to heat the boiler feedwater from the deaerator to a sub-enthalpy state to obtain sub-enthalpy water and input it into the steam drum. Both ends of the evaporator are connected to the steam drum pipeline, which is used to receive under-enthalpy water, heat it to a superheated state, and vaporize it. The steam drum is used to evaporate superheated hot water and achieve steam-water separation to generate saturated steam; The superheater is connected to the outlet pipe of the steam drum and is used to receive saturated steam and further heat it to a superheated state before outputting it to external steam users. The heat exchanger is connected to the regenerative heat water subsystem, which is also connected to the deaerator and the steam drum pipeline. The heat exchanger is used to heat the hot water in the regenerative heat water subsystem, thereby reducing the exhaust temperature of the waste heat flue gas and improving the utilization efficiency of waste heat. The thermal storage heat transfer water subsystem includes a thermal storage hot water boiler drum, a pressure regulating valve, a temperature regulating valve, and a hot water circulation pump or a hot water booster pump. The inlet of the thermal storage hot water boiler drum is connected to the heat transfer water heat exchanger, and the outlet is connected to the hot water user. The inlet of the temperature regulating valve is connected to the steam drum, and the outlet is connected to the thermal storage hot water boiler drum. The inlet of the pressure regulating valve is connected to the thermal storage hot water boiler drum, and the outlet is connected to the deaerator. The hot water circulation pump or the hot water booster pump increases the circulation power of the heat transfer water in the thermal storage heat transfer water subsystem.

2. The regenerative steam-hot water cogeneration waste heat boiler system according to claim 1, characterized in that, It also includes a boiler makeup water / feed water subsystem, which includes the deaerator, makeup water pump, feed water pump and desuperheating and pressure reducing valve, used to provide pressure and water source for the boiler to generate qualified steam; The deaerator is used to receive saturated steam from the steam drum and to deaerate the boiler feedwater entering the deaerator. The water supply pump is installed on the pipeline connecting the external boiler and the feedwater preheater, and is used to pressurize the boiler and supply water to the feedwater preheater. The feedwater pump is located on the pipeline connecting the deaerator and the economizer, and is used to pressurize the boiler feedwater and send it to the economizer. The desuperheating and pressure reducing valve is installed on the pipeline between the deaerator and the steam drum, and is used to desuperheat and reduce the pressure of the received saturated steam before sending it into the deaerator.

3. The regenerative steam-hot water cogeneration waste heat boiler system according to claim 1, characterized in that, The regenerative hot water boiler drum is used to store, regulate, and output hot water required for production / domestic use. Its operating pressure is lower than that of the steam drum but higher than that of the deaerator. The temperature regulating valve is used to regulate the temperature of the hot water inside the thermal storage hot water boiler drum. The pressure regulating valve is used to release the pressure of hot water that has expanded due to heating, thereby maintaining the pressure stability of the thermal storage heat medium water subsystem. The hot water circulation pump or the hot water booster pump improves the circulation power of the thermal medium water circulation in the thermal storage thermal medium water subsystem. The hot water users include ORC generator sets, lithium bromide refrigeration units, low-temperature multi-effect seawater desalination equipment, and heating and heat exchange systems.

Images