CN212039062U

CN212039062U - Evaporation energy-saving system

Info

Publication number: CN212039062U
Application number: CN202020650999.5U
Authority: CN
Inventors: 曹嵘; 张小磊; 刘绍云
Original assignee: Hunan Xiangheng Salt Chemical Co ltd
Current assignee: Hunan Xiangheng Salt Chemical Co ltd
Priority date: 2020-04-26
Filing date: 2020-04-26
Publication date: 2020-12-01
Anticipated expiration: 2030-04-26

Abstract

An evaporation energy-saving system comprises a steam turbine, an MVR evaporation plant, a preheater and a plate heat exchanger; the MVR evaporation device comprises an MVR compressor and an evaporator; the output end of the steam turbine is connected with the MVR compressor, and the output end of the MVR compressor is connected with the evaporator; a liquid outlet of the plate heat exchanger is sequentially connected with a preheater and an evaporator through pipelines; and the low-pressure steam outlet of the steam turbine is connected with a preheater pipeline. The utility model adopts the steam turbine to replace the motor of the MVR system, which is beneficial to arranging the MVR evaporation equipment in the area with poor electric power; the steam energy conversion type is changed from kinetic energy-electric energy-internal energy into kinetic energy-internal energy, so that the energy utilization rate is improved; and the secondary steam generated by the MVR compressor compression evaporator is driven, and the steam after passing through the steam turbine is used as the raw steam of the MEE evaporation equipment, so that the combined process of simultaneously operating the MVR and MEE systems is realized, and the utilization rate of energy is greatly improved.

Description

Evaporation energy-saving system

Technical Field

The utility model relates to a MVR technical field, especially an evaporation economizer system.

Background

The conventional evaporation energy-saving technology adopts one or more of multi-effect evaporation (MEE), Thermal Vapor Recompression (TVR) and Mechanical Vapor Recompression (MVR). The MVR technology is characterized in that a mechanical compressor is used for compressing secondary steam generated by an evaporation tank, so that the pressure and the temperature of the steam are increased, the enthalpy is increased, the secondary steam is sent to a heating chamber of an evaporator and used as heating steam to generate the steam, the feed liquid is kept in an evaporation state, and the heating steam transfers heat to the material to be condensed into water. Because the compressors in the MVR system are all driven by electric power, namely the compressors are driven by the motor to compress to generate secondary steam, a large amount of electric energy is consumed, the general MVR systems are all arranged in regions with rich electric power resources, but most of domestic regions have power shortage and the steam is cheap, so that the MVR evaporator which consumes the electric power by taking the steam saving as a core is poor in domestic development condition. In addition, when the system is started, enough steam needs to be provided to enable the system to generate secondary steam, and then the compressor of the MVR can be started; the motor of the compressor is generally large, the starting current is high, and the investment cost of power grid transformation is relatively large.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the above-mentioned not enough of prior art and providing an evaporation economizer system that application scope is wide, and energy utilization is rateed highly, and the running cost is low.

The technical scheme of the utility model is that: an evaporation energy-saving system comprises a steam turbine, an MVR evaporation plant, a preheater and a plate heat exchanger; the MVR evaporation device comprises an MVR compressor and an evaporator; the output end of the steam turbine is connected with the MVR compressor, and the output end of the MVR compressor is connected with the evaporator; a liquid outlet of the plate heat exchanger is sequentially connected with a preheater and an evaporator through pipelines; and the low-pressure steam outlet of the steam turbine is connected with a preheater pipeline.

Further, a steam inlet of the steam turbine is connected with an input heat source; the input heat source is also connected with an input end pipeline of the temperature and pressure reducer, the output end of the temperature and pressure reducer is divided into two branches, one branch is connected with the evaporator, and the other branch is connected with the MEE evaporation device and/or the TVR evaporation device.

Furthermore, a steam outlet of the evaporator is connected with the MVR compressor through a steam washing tower.

Furthermore, a low-pressure steam outlet of the steam turbine is divided into two output branches, one branch is connected with the MEE evaporation device and/or the TVR evaporation device through a pipeline, and the other branch is connected with the preheater.

Further, the input heat source is high-pressure steam output by a boiler.

Further, still be equipped with the oxygen-eliminating device between the connecting tube of pre-heater and evaporimeter, plate heat exchanger's liquid outlet pipe connection pre-heater, oxygen-eliminating device and evaporimeter in proper order.

Furthermore, the water outlets of the evaporator and the preheater are both connected with a condensation water bucket, and the water outlet of the condensation water bucket is connected with the plate heat exchanger.

The utility model has the advantages that: the utility model adopts the steam turbine to replace the motor of the MVR system, which is beneficial to arranging the MVR evaporation equipment in the area with poor electric power; the MVR compressor is directly driven to work by the steam turbine, and the steam energy conversion type generated by the boiler is changed from kinetic energy-electric energy-internal energy into kinetic energy-internal energy, so that the energy utilization rate is improved; the MVR compressor is driven to compress to generate secondary steam, the steam after passing through the steam turbine is used as raw steam of the MEE evaporation equipment, the joint process of simultaneously operating the MVR and the MEE system is realized, and the utilization rate of energy is greatly improved. By optimizing the MVR system, the influence of the power grid layout on the MVR system is reduced, and the running cost is reduced. And through setting up steam turbine and pressure reducer that reduces the temperature, start MVR compressor that can be more quick.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Detailed Description

The invention will be described in further detail with reference to the drawings and specific examples.

As shown in fig. 1: an evaporation energy-saving system comprises a steam turbine, an MVR evaporation plant, a temperature and pressure reduction device, a preheater, a plate heat exchanger and an MEE evaporation plant; wherein, MVR evaporation plant includes MVR compressor and evaporimeter.

The steam turbine is a prime mover for directly converting heat energy of steam into rotational mechanical energy, and is mainly used in a thermal power plant to drive a generator to generate electricity. In this embodiment, the steam inlet of steam turbine passes through the pipe connection boiler, and the MVR compressor is connected to the output of steam turbine, and the evaporimeter is connected to the output of MVR compressor. High-pressure steam generated by the boiler is distributed to the steam turbine to drive the MVR compressor to operate to compress secondary steam, and then the MVR evaporator is operated. This embodiment utilizes the direct MVR compressor operation that drives of steam turbine, has following advantage: on one hand, a generator set and a motor are not needed in the middle, the energy form conversion times are less, and the energy loss is less; on the other hand, the steam turbine can adapt to the steam of different pressure grades as the power supply, is favorable to according to the steam price difference of the different grades in location, through optimizing the evaporation intensity of ratio MVR device and MEE device, reduces the running cost.

In this embodiment, the boiler is further connected with an input end pipeline of the temperature and pressure reducer, an output end of the temperature and pressure reducer is divided into two branches, one branch is connected with the MVR evaporator, and the other branch is connected with the MEE evaporator; the steam outlet of the evaporator is connected with the MVR compressor through the steam washing tower. Through setting up the pressure reducer that reduces the temperature parallelly connected with the MVR compressor, can regard as the start-up steam or the supplementary steam of MVR system on the one hand, on the other hand can be used for adjusting MEE evaporation plant's raw steam pressure and temperature, and better control MEE evaporation plant's first effect material temperature is favorable to MVR and MEE's ally oneself with usefulness. The secondary steam that the raw steam that the evaporimeter adopted the MVR compressor compression promptly comes with raw materials liquid heat transfer, can also get into the MVR system as starting steam through the steam of pressure reducer input in the evaporimeter, because need provide sufficient steam when the MVR compressor starts and just can start after letting the system produce secondary steam. And the MEE evaporation device is multi-effect evaporation, and steam output by temperature and pressure reduction can be used for adjusting the pressure and temperature of raw steam in the MEE evaporation device so as to better control the temperature of the first effect material.

In this embodiment, the low-pressure steam after passing through the steam turbine is used for preheating the MEE evaporation plant and the system raw material liquid, that is, the heat sources of the preheater and the MEE evaporation plant are the low-pressure steam after the work of the steam turbine. The method specifically comprises the following steps: the low-pressure steam outlet of the steam turbine is divided into two output branches, one branch is connected with the MEE evaporation plant through a pipeline, and the other branch is connected with the preheater. In this embodiment, it can be said that the raw material liquid is preheated by using the low-pressure steam discharged from the steam turbine as the heat source, and the latent heat of the steam can be more sufficiently utilized.

In this embodiment, before the evaporimeter of raw materials liquid entering MVR device, heat up through plate heat exchanger and pre-heater in proper order, make full use of heat energy. The method specifically comprises the following steps: the liquid outlet of the plate heat exchanger is sequentially connected with the preheater and the evaporator through pipelines. The raw material liquid is heated in the plate heat exchanger for the first time, then enters the preheater for the second time under the action of low-pressure steam output by the steam turbine, and then enters the evaporator, the material liquid is heated by the heating steam in the evaporator, so that the material liquid maintains an evaporation state, and the formed finished material liquid is output. The heating steam in this embodiment is the secondary steam generated by the MVR compressor.

In addition, a deaerator can be added between the connecting pipelines of the preheater and the evaporator, namely, a liquid outlet of the plate type heat exchanger is sequentially connected with the preheater, the deaerator and the evaporator through pipelines. Therefore, the raw material liquid can be removed by the deaerator and then enters the evaporator after being dissolved in the feed liquid.

In this embodiment, the heat sources of the plate heat exchanger are condensed water of the preheater and condensed water generated by the evaporator of the MVR. The method specifically comprises the following steps: the water outlets of the evaporator and the preheater are both connected with a condensation water bucket, and the water outlet of the condensation water bucket is connected with the plate heat exchanger. Heating the feed liquid by the heating steam in the evaporator to maintain the feed liquid in an evaporation state, and condensing the heating steam into water to enter a condensation water barrel; and after the low-pressure steam of the preheater heats the raw material liquid, the low-pressure steam is condensed into water and also enters a condensation water bucket. And the condensed water in the condensed water bucket enters the plate heat exchanger to heat the raw material liquid. And the water outlet of the plate heat exchanger outputs condensed water after heat exchange.

The working principle of the embodiment is as follows: the raw material liquid enters a plate heat exchanger to exchange heat with a heat source in the plate heat exchanger, and the heat source of the plate heat exchanger is condensed water of a preheater and condensed water generated by an MVR evaporator; the heat-exchanged raw material liquid is heated and then enters the preheater to exchange heat with a heat source in the preheater, the heat source in the preheater is low-pressure steam which does work through a steam turbine, and the low-pressure steam is condensed into water to enter a condensation water bucket after releasing heat and is used as the heat source of the plate heat exchanger; the heat-exchanged raw material liquid is heated for the second time and then enters a deaerator to remove part of soluble gas dissolved in the raw material liquid; finally, the steam enters an evaporator and exchanges heat with the heating steam of the evaporator; wherein the heating steam of the evaporator comes from secondary steam compressed by an MVR compressor; heating the raw material liquid by heating steam in the evaporator to maintain the raw material liquid in an evaporation state, and outputting the formed finished material liquid; and the heating steam is condensed into water which enters a condensation water bucket and is used as a heat source of the plate heat exchanger. In addition, the steam turbine converts the high-pressure steam output by the boiler into mechanical energy to replace a motor of the MVR system, drives the MVR compressor to compress secondary steam generated by an MVR evaporator, and the low-pressure steam after the work of the steam turbine is respectively used as heat sources of the preheater and the MEE evaporation device. Meanwhile, high-pressure steam generated by the boiler can be cooled and decompressed through the temperature and pressure reducer, and then part of the output steam enters the MEE evaporation device to adjust the raw steam pressure and temperature of the MEE evaporation device; another portion is fed to the evaporator as make-up steam to provide enough steam to the MVR evaporator to generate secondary steam as quickly as possible. Can say that, parallelly connected through setting up the steam turbine and reducing the temperature and pressure ware, start MVR vaporization system that can be faster.

To sum up, the utility model adopts the steam turbine to replace the motor to drive the compressor to operate, and the key purpose is that most of the enterprises with the evaporation concentration equipment have the boiler or are positioned in the industrial park of central heating, have abundant steam, but are not necessarily in the area with abundant electric power, and the difficulty of MVR system reconstruction on the original system is relatively low; the turbine drives the MVR compressor to directly operate, so that the waste in the energy conversion process is reduced; the temperature and pressure reducing device is connected with the steam turbine in parallel, so that the steam turbine can be used as starting steam or supplementing steam of an MVR system on one hand, and can be used for adjusting the raw steam pressure and temperature of an MEE evaporation device on the other hand, the first effect material temperature of the MEE evaporation device is better controlled, and the MVR and MEE can be favorably used together; the MVR system and the MEE are combined, so that the system can reasonably adjust the running proportion of the system according to the steam selling price, and the optimal economic benefit is achieved.

It will be appreciated that the low pressure steam after work is applied by the turbine may also be used in a dryer, not just in the preheater and MEE evaporator applications. In addition, the MEE evaporation plant may be replaced by a TVR system, i.e., an MVR system is used in conjunction with the TVR system; or the MVR system, the TVR system and the MEE system are jointly used. Moreover, other high-pressure and high-speed fluids (such as compressed air and the like) can be used for driving a steam turbine to independently operate the MVR system.

Claims

1. An evaporation energy-saving system is characterized by comprising a steam turbine, an MVR evaporation plant, a preheater and a plate heat exchanger; the MVR evaporation device comprises an MVR compressor and an evaporator; the output end of the steam turbine is connected with the MVR compressor, and the output end of the MVR compressor is connected with the evaporator; a liquid outlet of the plate heat exchanger is sequentially connected with a preheater and an evaporator through pipelines; and the low-pressure steam outlet of the steam turbine is connected with a preheater pipeline.

2. The evaporative energy saving system according to claim 1, wherein the steam inlet of the steam turbine is connected to an input heat source; the input heat source is also connected with an input end pipeline of the temperature and pressure reducer, the output end of the temperature and pressure reducer is divided into two branches, one branch is connected with the evaporator, and the other branch is connected with the MEE evaporation device and/or the TVR evaporation device.

3. The evaporation energy-saving system according to claim 1 or 2, wherein the steam outlet of the evaporator is connected with the MVR compressor through a steam washing tower.

4. The evaporative energy saving system according to claim 1 or 2, wherein the low-pressure steam outlet of the steam turbine is divided into two output branches, one branch is connected with the MEE evaporation device and/or the TVR evaporation device through a pipeline, and the other branch is connected with the preheater.

5. The evaporative economizer system of claim 2 wherein the input heat source is high pressure steam from a boiler.

6. The evaporation energy-saving system according to claim 1 or 2, wherein a deaerator is further arranged between the connection pipeline of the preheater and the evaporator, and a liquid outlet of the plate heat exchanger is sequentially connected with the preheater, the deaerator and the evaporator through pipelines.

7. The evaporation energy-saving system according to claim 1 or 2, wherein the water outlets of the evaporator and the preheater are both connected with a condensation water bucket, and the water outlet of the condensation water bucket is connected with the plate heat exchanger.