阅读说明：本技术 一种聚酯酯化蒸汽余热综合利用系统 (Polyester esterification steam waste heat comprehensive utilization system ) 是由 李健 梁龙辉 于 2020-06-23 设计创作，主要内容包括：本发明公开了一种聚酯酯化蒸汽余热综合利用系统,包括酯化蒸汽分离塔、冷却回路、有机朗肯循环发电系统以及凝结水处理系统；冷却回路的输入端与有机朗肯循环发电系统的输入端均与酯化蒸汽分离塔的气相出口管道相连；有机朗肯循环发电系统的热源输出口与冷却回路的输出口均与凝结水处理系统的入口管道相连；凝结水处理系统的输出口管道连接至酯化蒸汽分离塔的回流口。本发明的有益效果：能够实现全年运行,提高酯化蒸汽余热的综合利用效率,经济效益高。(The invention discloses a polyester esterification steam waste heat comprehensive utilization system, which comprises an esterification steam separation tower, a cooling loop, an organic Rankine cycle power generation system and a condensed water treatment system, wherein the esterification steam separation tower is connected with the cooling loop; the input end of the cooling loop and the input end of the organic Rankine cycle power generation system are both connected with a gas-phase outlet pipeline of the esterification steam separation tower; the heat source output port of the organic Rankine cycle power generation system and the output port of the cooling loop are both connected with an inlet pipeline of the condensed water treatment system; an output port pipeline of the condensed water treatment system is connected to a reflux port of the esterification steam separation tower. The invention has the beneficial effects that: can realize annual operation, improve the comprehensive utilization efficiency of the residual heat of the esterification steam and have high economic benefit.)

1. The utility model provides a polyester esterification steam waste heat comprehensive utilization system which characterized in that: the system comprises an esterification steam separation tower (1), a cooling loop, an organic Rankine cycle power generation system and a condensed water treatment system; the inlet of the cooling loop and the heat source inlet of the organic Rankine cycle power generation system are both connected with a gas phase outlet pipeline of the esterification steam separation tower (1); the heat source outlet of the organic Rankine cycle power generation system and the outlet of the cooling loop are both connected with an inlet pipeline of the condensed water treatment system; an outlet pipeline of the condensed water treatment system is connected to a reflux port of the esterification steam separation tower (1);

the cooling loop is one or more of an air cooler cooling loop, a lithium bromide refrigerating unit cooling loop and an organic Rankine cycle power generation cooling loop; each cooling loop comprises a steam regulating valve and a cooling device connected with the steam regulating valve through a pipeline;

the organic Rankine cycle power generation system comprises a third steam regulating valve (2-3), an evaporator (3) with a preheating section and an organic Rankine cycle power generation device, wherein the steam valve is connected with a steam inlet pipeline of the evaporator at the preheating section; a working medium inlet and outlet of the preheating section evaporator are connected with an organic Rankine cycle power generation device in parallel;

the condensed water treatment system comprises a condensed water cooler (10), a condensed water storage tank (11) and a reflux pump (12) which are connected in sequence through pipelines.

2. The polyester esterification steam waste heat comprehensive utilization system according to claim 1, characterized in that: the organic Rankine cycle power generation device comprises a turbine power generation connecting loop and a turbine bypass power generation connecting loop; the concrete connection is as follows: a working medium outlet of the preheating section evaporator is sequentially connected with a turbine valve (5), a turbine generator (6), a condenser (7), a working medium pump (8) and a working medium inlet of the evaporator through pipelines; and the two ends of the pipeline where the turbine valve (5) and the turbine generator (6) are positioned are connected with a turbine bypass valve (4) in parallel.

3. The polyester esterification steam waste heat comprehensive utilization system according to claim 1, characterized in that: the air cooler cooling circuit comprises a first steam regulating valve (2-1) and an air cooler (13); the steam at the gas phase outlet of the esterification steam separation tower (1) enters an air cooler (13) through a first steam regulating valve (2-1); the output pipeline of the air cooler (13) is connected with the inlet pipeline of the condensed water treatment system.

4. The polyester esterification steam waste heat comprehensive utilization system according to claim 1, characterized in that: the cooling loop of the lithium bromide refrigerating unit comprises a second steam regulating valve (2-2) and a lithium bromide refrigerating unit (9-1); steam at a gas phase outlet of the esterification steam separation tower (1) enters a lithium bromide refrigerating unit (9-1) through a second steam regulating valve (2-2); the heat source outlet of the lithium bromide refrigerating unit (9-1) is connected with the inlet pipeline of the condensed water treatment system.

5. The polyester esterification steam waste heat comprehensive utilization system according to claim 1, characterized in that: the organic Rankine cycle power generation cooling circuit comprises a fourth steam regulating valve (2-4) and at least one group of organic Rankine cycle power generation devices (9-2); steam at a gas phase outlet of the esterification steam separation tower (1) enters the organic Rankine cycle power generation device through a third steam regulating valve (2-3); and a heat source output pipeline of the organic Rankine cycle power generation device is connected with an inlet pipeline of the condensed water treatment system.

Technical Field

The invention relates to the technical field of polyester esterification steam waste heat utilization, in particular to a polyester esterification steam waste heat comprehensive utilization system.

Background

In the polyester synthesis process, esterification steam at about 103 ℃ is generated in the esterification stage, and a large amount of low-grade heat is carried by the part of the esterification steam. Taking a 600t/d polyester production plant as an example, theoretically, the plant would produce about 220t of steam per day and would release about 5.4 x 108 kJ of latent heat (equivalent to 18.4 t standard coal) during liquefaction. In the traditional process, the esterification steam is generally cooled by an air cooler, and a fan of the air cooler consumes a large amount of electric energy, so that the energy waste is huge. In order to improve the utilization efficiency of the waste heat of the esterification steam, part of polyester production enterprises adopt a lithium bromide refrigerating unit to recycle the waste heat of the esterification steam, but the lithium bromide refrigerating unit is only used in summer, and the esterification steam is still cooled by an air cooler in winter and spring and autumn, so that the comprehensive heat energy utilization efficiency of the lithium bromide refrigerating unit is low.

The organic Rankine cycle power generation device can obtain higher vapor pressure under the low temperature condition (80-300 ℃) by utilizing the low boiling point characteristic of organic working media (such as R134a, R245fa and the like), push an expansion machine to work, and drive a generator to generate power, so that the conversion from low-grade heat energy to high-grade electric energy is realized.

Disclosure of Invention

1. The technical problem to be solved is as follows:

aiming at the technical problems, the invention provides a comprehensive utilization system for the waste heat of polyester esterification steam, the esterification steam from a separation tower can selectively enter an air cooler, a lithium bromide refrigerating unit and an organic Rankine cycle power generation device according to actual conditions, so that not only can the effective recycling of low-grade heat energy be realized, but also the stability of a polyester production line is ensured.

2. The technical scheme is as follows:

the utility model provides a polyester esterification steam waste heat comprehensive utilization system which characterized in that: the system comprises an esterification steam separation tower, a cooling loop, an organic Rankine cycle power generation system and a condensed water treatment system; the inlet of the cooling loop and the heat source inlet of the organic Rankine cycle power generation system are both connected with a gas phase outlet pipeline of the esterification steam separation tower; the heat source outlet of the organic Rankine cycle power generation system and the outlet of the cooling loop are both connected with an inlet pipeline of the condensed water treatment system; and an outlet pipeline of the condensed water treatment system is connected to a reflux port of the esterification steam separation tower.

The cooling loop is one or more of an air cooler cooling loop, a lithium bromide refrigerating unit cooling loop and an organic Rankine cycle power generation cooling loop; each cooling loop comprises a steam regulating valve and a cooling device connected with the steam regulating valve through a pipeline.

The organic Rankine cycle power generation system comprises a steam valve, an evaporator with a preheating section and an organic Rankine cycle power generation device, wherein the steam valve is connected with a steam inlet pipeline of the evaporator with the preheating section; and a working medium inlet and outlet of the preheating section evaporator are connected in parallel with the organic Rankine cycle power generation device.

The condensed water treatment system comprises a condensed water cooler, a condensed water storage tank and a reflux pump which are connected in sequence through pipelines.

Further, the organic Rankine cycle power generation device comprises a turbine power generation connecting loop and a turbine bypass power generation connecting loop; the concrete connection is as follows: a working medium outlet of the preheating section evaporator is sequentially connected with a turbine valve, a turbine generator, a condenser, a working medium pump and a working medium inlet of the evaporator through pipelines; and the two ends of the pipeline where the turbine valve and the turbine generator are positioned are connected with a turbine bypass valve in parallel.

Further, the air cooler cooling circuit includes a first steam regulating valve and an air cooler; steam at a gas phase outlet of the esterification steam separation tower enters an air cooler through a first steam regulating valve; the output pipeline of the air cooler is connected with the inlet pipeline of the condensed water treatment system.

Furthermore, the cooling loop of the lithium bromide refrigerating unit comprises a second steam regulating valve and the lithium bromide refrigerating unit; steam at a gas phase outlet of the esterification steam separation tower enters the lithium bromide refrigerating unit through a second steam regulating valve; and a heat source outlet of the lithium bromide refrigerating unit is connected with an inlet pipeline of the condensed water treatment system.

Further, the organic Rankine cycle power generation cooling circuit comprises a third steam regulating valve and at least one set of organic Rankine cycle power generation devices; steam at a gas phase outlet of the esterification steam separation tower enters the organic Rankine cycle power generation cooling group through a third steam regulating valve; and a heat source output pipeline of the organic Rankine cycle power generation device is connected with an inlet pipeline of the condensed water treatment system.

3. Has the advantages that:

(1) the polyester esterification steam waste heat comprehensive power generation system provided by the invention can realize annual operation, improves the comprehensive utilization efficiency of esterification steam waste heat, and has high economic benefit.

(2) The invention can divide the esterification steam in the separation tower into three paths, and each path can control the steam flow by the steam regulating valve which is dynamically regulated, thereby realizing the stable operation of the polyester production line under the condition of regulating the flow fluctuation.

(3) The preheater in the organic Rankine cycle power generation device can improve the thermoelectric conversion efficiency of the generator set, further reduce the temperature of the condensed water and effectively reduce the heat load of the condensed water cooler.

(4) The turbine bypass mode in the invention ensures that the organic Rankine cycle power generation device can keep the operation of the organic Rankine cycle under the condition of not outputting power, continuously cools the esterification steam, and further ensures the stable operation of the polyester production line.

Drawings

FIG. 1 is a connection diagram of embodiment 1 of the present invention;

FIG. 2 is a connection diagram of embodiment 2 of the present invention;

fig. 3 is a connection diagram of embodiment 3 of the present invention.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

The utility model provides a polyester esterification steam waste heat comprehensive utilization system which characterized in that: the system comprises an esterification steam separation tower 1, a cooling loop, an organic Rankine cycle power generation system and a condensed water treatment system; the inlet of the cooling loop and the heat source inlet of the organic Rankine cycle power generation system are both connected with a gas phase outlet pipeline of the esterification steam separation tower; the heat source outlet of the organic Rankine cycle power generation system and the outlet of the cooling loop are both connected with an inlet pipeline of the condensed water treatment system; and an outlet pipeline of the condensed water treatment system is connected to a reflux port of the esterification steam separation tower.

The cooling loop is one or more of an air cooler cooling loop, a lithium bromide refrigerating unit cooling loop and an organic Rankine cycle power generation cooling loop; each cooling loop comprises a steam regulating valve and a cooling device connected with the steam regulating valve through a pipeline.

The organic Rankine cycle power generation system comprises steam valves 2-4, an evaporator 3 with a preheating section and an organic Rankine cycle power generation device, wherein the steam valves are connected with a steam inlet pipeline of the evaporator of the preheating section; and a working medium inlet and outlet of the preheating section evaporator are connected in parallel with the organic Rankine cycle power generation device.

The condensed water treatment system comprises a condensed water cooler 10, a condensed water storage 11 and a reflux pump 12 which are connected in sequence through pipelines.

Further, the organic Rankine cycle power generation device comprises a turbine power generation connecting loop and a turbine bypass power generation connecting loop; the concrete connection is as follows: a working medium outlet of the preheating section evaporator is sequentially connected with a turbine valve 5, a turbine generator 6, a condenser 7, a working medium pump 8 and a working medium inlet of the evaporator through pipelines; and the turbine bypass valve 4 is connected in parallel at two ends of a pipeline where the turbine valve 5 and the turbine generator 6 are positioned.

Further, the air cooler cooling circuit includes a first steam regulating valve and an air cooler; the steam at the gas phase outlet of the esterification steam separation tower enters an air cooler 13 through a first steam regulating valve 2-1; the output pipeline of the air cooler is connected with the inlet pipeline of the condensed water treatment system.

Further, the cooling loop of the lithium bromide refrigerating unit comprises a second steam regulating valve 2-2 and a lithium bromide refrigerating unit 9-1; steam at a gas phase outlet of the esterification steam separation tower enters the lithium bromide refrigerating unit through a second steam regulating valve; and a heat source outlet of the lithium bromide refrigerating unit is connected with an inlet pipeline of the condensed water treatment system.

Further, the organic Rankine cycle power generation cooling circuit comprises a third steam regulating valve 2-3 and at least one group of organic Rankine cycle power generation devices 9-2; steam at a gas phase outlet of the esterification steam separation tower enters the organic Rankine cycle power generation device through a third steam regulating valve; and a heat source output pipeline of the organic Rankine cycle power generation device is connected with an inlet pipeline of the condensed water treatment system.