Evaporation system combined with waste heat recycling technology

Abstract

The utility model provides an evaporation system combined with a waste heat recycling technology, and relates to the technical field of evaporation and waste heat recycling. Comprising a multi-stage heater, an evaporation chamber and an absorption heat pump which are sequentially connected, live steam is introduced into a first-effect heater to serve as an evaporation heat source, a to-be-treated material is subjected to secondary preheating through a last-effect condensate water preheater and a live steam condensate water preheater and is introduced into a first-effect evaporation chamber to be evaporated and concentrated, the first-effect evaporation chamber is communicated with a second-effect heater, and the second-effect heater is communicated with an absorption heat pump. Secondary steam enters the second-effect heater to serve as a heat source, the second-effect evaporation chamber is communicated with the next-stage heater, and the like, the absorption type heat pump is communicated with the last-effect evaporation chamber, and the secondary steam in the last-effect evaporation chamber can be introduced into the absorption type heat pump to serve as a waste heat source to be absorbed and utilized; the heated circulating fluid in the heat pump is used for other technological processes or meets the heat using requirement. According to the system, evaporation and heat pump technologies are combined, final-stage steam heat in the evaporation process is recycled and used as a waste heat source to be recycled, and energy conservation and emission reduction are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to evaporation, waste heat recycling technical field especially is related to a kind of evaporation system in combination with waste heat recycling technology. BACKGROUND

[0002] Evaporation is a link of process flow, and a large amount of energy needs to be consumed. It plays a very important role in the processes of wastewater treatment, material concentration, waste solvent recovery treatment, etc. in petroleum, chemical industry and other industries.

[0003] At present, evaporation, concentration and crystallization processes in the fields of environmental protection, chemical industry, pharmaceutical industry, food industry and biological engineering widely use multi-effect evaporation technology. It utilizes the lower pressure of the next effect than the previous effect, so that the temperature of the next effect is lower than that of the previous effect. The exhaust steam discharged from the previous effect can be used to heat the next effect. Compared with single-effect evaporation, multi-effect evaporation can achieve higher thermal efficiency, realize cascade utilization of heat source, improve heat energy utilization rate, thereby saving energy cost; multi-effect evaporation technology can realize efficient removal of water in solution, thereby saving raw materials and reducing waste production. Under the same operating conditions, it can realize higher concentration multiple, thereby improving production efficiency and capacity.

[0004] Multi-effect evaporation is a system composed of single-effect evaporation. The secondary steam generated in the previous evaporation chamber is introduced into the next evaporation chamber as heating steam. Therefore, only the boiler steam is introduced into the first effect, and the secondary steam generated in the previous evaporation chamber is used in the subsequent evaporation, thereby realizing the reuse of energy. Each use is called an effect. The effect using boiler steam is generally called the first evaporation chamber, and the subsequent effects are called the second effect, the third effect, etc. Finally, when the secondary steam temperature and pressure of the last effect are too low to be used in the evaporation chamber, it enters the condenser to be converted into condensed water. This part of the process causes energy waste. Multi-effect evaporation can reach up to seven or even eight effects. In theory, the more the number of multi-effect evaporation effects, the more the saved live steam. However, with the increase of the number of evaporation chamber effects, the equipment investment and construction cost also increase accordingly.

[0005] In this process flow, the front end of the flow is a heating process, and the end of the flow is a cooling process. The condenser at the end is used to cool the last-effect steam. The circulating water in the condenser carries this part of heat to the cooling tower, which is not fully utilized, resulting in energy waste.

[0006] In view of the above reasons, the utility model provides an evaporation system combined with waste heat recycling technology, which can solve the above technical problems and realize energy saving and emission reduction. CONTENT OF THE UTILITY MODEL

[0007] The utility model discloses a kind of evaporation systems combined with waste heat recovery technology, which combines evaporation technology with heat pump technology, recovers the heat of last-stage steam in evaporation process, uses it as waste heat source, converts and reuses waste heat, realizes energy saving and emission reduction.

[0008] The utility model provides a kind of evaporation systems combined with waste heat recovery technology, comprising: multistage heater connected in turn, multistage evaporation chamber and absorption heat pump, wherein, after secondary preheating of the material to be treated is carried out in last-effect condensate preheater and live steam condensate preheater in turn, it is evaporated in the first effect evaporation chamber, live steam is input into the first effect heater as evaporation heat source to heat the first effect evaporation chamber, the material to be treated is continuously evaporated and concentrated in the first effect evaporation chamber, the first effect evaporation chamber is communicated with the second effect heater of next stage, the secondary steam generated is input into the second effect heater as heating heat source to heat the second effect evaporation chamber, the second effect evaporation chamber is communicated with the heater of next stage, the first effect evaporation chamber, the second effect evaporation chamber and next stage evaporation chamber are communicated in turn, and so on, the absorption heat pump is communicated with the last-effect evaporation chamber.

[0009] Preferably, the first effect heater is communicated with the live steam condensate preheater.

[0010] Preferably, the second effect heater, the heater located in the next stage thereof and the last-effect heater are all communicated with the last-effect condensate preheater.

[0011] Preferably, a part of live steam is extracted and input into the absorption heat pump as main heat source.

[0012] Preferably, the condensate outlets of the last-effect condensate preheater and the live steam condensate preheater are communicated with the absorption heat pump, and the condensate is input into the absorption heat pump.

[0013] Preferably, the inlet of the absorption heat pump is communicated with each evaporation chamber, so that secondary steam can be extracted and input into the absorption heat pump as auxiliary heat source, and the waste heat water outlet of the absorption heat pump is connected with each heater.

[0014] Preferably, a secondary steam condenser is further connected between the last-effect evaporation chamber and the absorption heat pump, and the condensate flowing out of the secondary steam condenser is input into the absorption heat pump.

[0015] Preferably, a heat-using end is further included, and the heat-using end is communicated with the hot water outlet of the absorption heat pump.

[0016] Preferably, an external input heat source is further included, and the external input heat source is communicated with the absorption heat pump, and the absorption heat pump is connected with each heater through a steam pipeline.

[0017] Preferably, the waste heat of the absorption heat pump is connected to the next process or discharged.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] 1. Combined with heat pump technology, the cooling and heating processes are combined together, the last effect steam is used as the waste heat source of the heat pump, the waste heat is recycled to heat the materials of the first effect or the second effect process, the waste heat is upgraded in grade, the scale of energy utilization is expanded, the consumption of the last effect steam to the circulating cooling water is reduced, and the energy saving potential is huge.

[0020] 2. By combining the absorption heat pump technology, the waste heat is converted and reused, which can be used for the heating process of the self-evaporation system, and can also be used to meet the heat demand of the external system. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme in the specific embodiment or prior art of the utility model, the drawings needed to be used in the specific embodiment or prior art description will be briefly introduced below, and obviously, the drawings in the following description are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating labor.

[0022] Figure 1 It is the system connection principle diagram of the utility model embodiment 1;

[0023] Figure 2 It is the system connection principle diagram of the utility model embodiment 2;

[0024] Figure 3 It is the system connection principle diagram of the utility model embodiment 3;

[0025] Figure 4 It is the system connection principle diagram of the utility model embodiment 4;

[0026] Figure 5 It is the system connection principle diagram of the utility model embodiment 5;

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 101: first effect heater;102: second effect heater;103: last effect heater;201: first effect evaporation chamber;202: second effect evaporation chamber;203: last effect evaporation chamber;3: live steam condensate preheater;4: last effect condensate preheater;5: absorption heat pump;6: heat using end;7: secondary steam condenser. DETAILED DESCRIPTION

[0029] The technical solutions of the utility model will be described clearly and completely in combination with the embodiments, obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative labor belong to the protection scope of the utility model.

[0030] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like are the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0031] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise explicitly and specifically limited. In addition, the terms "mounting", "connection", "connection" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For the ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0032] The following will be introduced as a typical process of three-effect evaporation process for high-salt wastewater treatment.

[0033] Evaporation method is used for evaporation desalination treatment of high-salt wastewater and high-salt wastewater, and three-effect evaporation desalination method is a kind of way currently used in evaporation industry. Multi-effect evaporation is a multi-stage series concentration process, and the operation parameters of each effect are the same as those of single-effect evaporation, but the process parameters of each effect are mutually restricted. The three-effect evaporation chamber evaporation system adopts continuous feeding and continuous discharging production mode.

[0034] Example 1

[0035] As Figure 1As shown, this embodiment provides an evaporation system combined with waste heat recovery technology, including: multi-stage heaters connected in sequence, multi-stage evaporation chambers and absorption heat pumps. In this embodiment, the heaters are the first-effect heater 101, the second-effect heater 102 and the last-effect heater 103 in sequence, and the evaporation chambers are the first-effect evaporation chamber 201, the second-effect evaporation chamber 202 and the last-effect evaporation chamber 203 in sequence. Raw steam is introduced into the first-effect heater 101 as an evaporation heat source for heating the first-effect evaporation chamber 201. In this embodiment, the material to be processed is high-salt wastewater. After the high-salt wastewater is preheated twice through the last-effect condensate preheater 4 and the raw steam condensate preheater 3 in sequence, it is introduced into the pipe side of the first-effect evaporation chamber 201 under the action of a circulating pump, and heat is exchanged with the raw steam to heat the high-salt wastewater in the pipe side. The heater 101 is connected to the raw steam condensate preheater 3. After the raw steam condenses into water, it serves as the heat source of the first-effect condensate preheater 3 to preheat the high-salt wastewater, thereby fully utilizing the latent heat of the raw steam. After the secondary preheating, the material to be treated is first continuously evaporated and concentrated in the first-effect evaporation chamber 201. The first-effect evaporation chamber 201 is connected to the second-effect heater 102 of the next stage. The secondary steam generated in the first-effect evaporation chamber 201 enters the second-effect heater 102 as motive steam to heat the second-effect evaporation chamber 202, causing the material to further evaporate therein. The second-effect evaporation chamber 202 is connected to the last-effect heater 103 of the next stage. The arrangement is similar. The first-effect evaporation chamber 201, the second-effect evaporation chamber 202, and the third-effect evaporation chamber 203 are sequentially connected through a balancing pipe, and the absorption heat pump 5 is connected to the last-effect evaporation chamber 203.

[0036] The material processing process within the evaporation system is as follows: High-salt wastewater first enters the first-effect evaporation chamber 201, where it continuously evaporates, maintaining a substantially constant material concentration. Under negative pressure, the material in the first-effect evaporation chamber 201 is transferred, controlled by an automatic valve, to the second-effect evaporation chamber 202. After further evaporation in the second-effect evaporation chamber 202, it is also transferred to the final-effect evaporation chamber 203. The absorption heat pump 5 is connected to the final-effect evaporation chamber 203. The secondary steam in the final-effect evaporation chamber 203 can be passed into the absorption heat pump 5 as a waste heat source, where it is absorbed and utilized. The heated circulating fluid in the absorption heat pump 5 is then used to heat other process steps or to meet domestic heating needs.

[0037] The working process of live steam is as follows: the live steam is reduced in pressure by a first heater 101, enters the shell side of a first evaporation chamber 201, and is heated for evaporation; the secondary steam generated by the first evaporation chamber 201 enters the shell side of a second evaporation chamber 202, and is heated for the second evaporation; in this way, the secondary steam generated by the second evaporation chamber 202 enters the shell side of a last evaporation chamber 203, and is heated for the last evaporation; the secondary steam generated by the last evaporation is partly used for preheating the feed, and most of it enters an absorption heat pump 5 as a waste heat source and is absorbed and utilized. In this process, the live steam condensate of the first evaporation enters the shell side of the second evaporation chamber 202 through a pipeline, the secondary steam condensate of the second evaporation enters the shell side of the last evaporation chamber 203 through a pipeline, and the condensate of the last evaporation chamber 203 enters a condensate tank and is then pumped out of the system by a condensate pump.

[0038] The absorption heat pump 5 is widely used in the field of waste heat recovery. It uses a small amount of high-temperature heat source as a driving heat source to generate a large amount of medium-temperature useful heat, i.e. it uses high-temperature heat to drive the heat energy of a low-temperature heat source to be increased to a medium temperature, thereby improving the utilization efficiency of heat energy, and its performance coefficient is greater than 1, being 1.5-2.5.

[0039] In this embodiment, the second heater 102 and the last heater 103 located at the lower level thereof are in communication with the last condensate preheater 4, and a small part of the secondary steam used for heating is condensed and introduced into the last condensate preheater 4 to preliminarily preheat the material, thereby fully utilizing the latent heat of the secondary steam.

[0040] In this embodiment, a part of the live steam is extracted and connected to the absorption heat pump 5 as a main heat source. The condensate outlets of the last condensate preheater 4 and the live steam condensate preheater 3 are in communication with the absorption heat pump 5, and the condensate is introduced into the absorption heat pump 5, so that the latent heat of the condensate can be further recovered and utilized.

[0041] In this embodiment, the system further comprises a heat utilization end 6, which is in communication with the hot water outlet of the absorption heat pump 5. The waste heat of the evaporation system absorbed by the absorption heat pump 5 can be used for heating or domestic hot water demand of the heat utilization end 6, and the waste heat generated by the absorption heat pump 5 is connected to the next process or discharged.

[0042] In this embodiment, the absorption heat pump 5 is introduced, which indirectly reduces the use of live steam. From the perspective of energy balance, the heat loss in the multi-effect evaporation process is not much, except for the heat loss of the container surface and the heating of the material. Due to the heat increasing function of the heat pump system, 1.5-2.5 parts of heat can be generated under the premise of consuming one part of steam. Therefore, compared with the system before the transformation, the new system increases 0.5-1.5 parts of heat. In the case of using the heat externally, the same volume of live steam can not only meet the process operation of the system, but also output heat to the external system, achieving the effect of waste heat recovery and reuse.

[0043] Embodiment 2

[0044] As Figure 2 shown, the embodiment provides a kind of evaporation system combined with waste heat recycling technology, including: multistage sequentially connected heater, multistage evaporation chamber and absorption heat pump, in the embodiment, heater is one-effect heater 101, two-effect heater 102 and last-effect heater 103 in turn, evaporation chamber is one-effect evaporation chamber 201, two-effect evaporation chamber 202 and last-effect evaporation chamber 203 in turn, wherein, live steam is imported into one-effect heater 101 as evaporation heat source, in the embodiment, the material to be treated is high-salt wastewater, high-salt wastewater is sequentially preheated in last-effect condensate preheater 4 and live steam condensate preheater 3, under the action of circulating pump, live steam is decompressed and heated to high-salt wastewater in the tube side of one-effect evaporation chamber 201, one-effect heater 101 is communicated with live steam condensate preheater 3, and live steam is condensed into water and used as the heat source of one-effect condensate preheater 3 to preheat high-salt wastewater, so that the latent heat of live steam is fully utilized;One-effect evaporation chamber 201 is communicated with two-effect heater 102 of next stage, and two-effect heater 102 is communicated with last-effect heater 103 of next stage, and so on, one-effect evaporation chamber 201, two-effect evaporation chamber 202 and three-effect evaporation chamber 203 are communicated through balance pipe, and last-effect evaporation chamber 203 is communicated with absorption heat pump 5 through secondary steam condenser 7.

[0045] The processing flow of material in evaporation system is as follows: high-salt wastewater material first enters one-effect evaporation chamber 201, and continuously evaporates in one-effect evaporation chamber 201, and the concentration of material remains basically unchanged;The material in one-effect evaporation chamber 201 is transferred into two-effect evaporation chamber 202 under the action of negative pressure controlled by automatic valve, and further evaporates in two-effect evaporation chamber 202, and is also transferred into last-effect evaporation chamber 203. Last-effect evaporation chamber 203 is communicated with absorption heat pump 5 through secondary steam condenser 7, and secondary steam in last-effect evaporation chamber 203 is condensed in secondary steam condenser 7 first, and the condensed water flows into absorption heat pump 5 as waste heat source of absorption heat pump 5, and is absorbed and utilized, and the heated circulating fluid in absorption heat pump 5 is used for heating section of other process flow, or is used to meet the demand of domestic heat.

[0046] The working process of live steam is as follows: the live steam is reduced in pressure by a primary heater 101, and then enters the shell side of a primary evaporation chamber 201 to be heated for evaporation; the secondary steam generated by the primary evaporation chamber 201 enters the shell side of a secondary evaporation chamber 202 to be heated for secondary evaporation; in this way, the secondary steam generated by the secondary evaporation chamber 202 enters the shell side of a final evaporation chamber 203 to be heated for final evaporation; the secondary steam generated by the final evaporation chamber is partly used for preheating the feed, and is mostly condensed in a secondary steam condenser 7, and the condensed water enters an absorption heat pump 5 as a waste heat source to be absorbed and utilized. In this process, the primary live steam condensate water enters the shell side of the secondary evaporation chamber 202 through a pipeline, the secondary steam condensate water enters the shell side of the final evaporation chamber 203 through a pipeline, and the final evaporation chamber 203 condensate water enters a condensate water tank, and is then pumped out of the system by a condensate water pump.

[0047] In this embodiment, the secondary steam condenser 7 is connected with a vacuum system, which extracts the uncondensed gas generated in the evaporation system, so that the secondary steam condenser 7 and the evaporation chambers are kept in a negative pressure state, and the evaporation efficiency of the evaporation system is improved. Under the action of negative pressure, the secondary steam generated by the waste water in the third evaporation chamber 203 automatically enters the secondary steam condenser 7, and under the cooling of the circulating cooling water, the secondary steam is quickly converted into condensate water and enters the condensate water tank, and then is led to the absorption heat pump 5.

[0048] In this embodiment, the secondary heater 102 and the final heater 103 located below it are connected with the final condensate water preheater 4, and the secondary steam condensed in the secondary heater 102 and the final heater 103 is led into the final condensate water preheater 4 to be used for preheating the material, so that the latent heat of the secondary steam is fully utilized.

[0049] In this embodiment, a part of the live steam is extracted and connected to the absorption heat pump 5 as a main heat source. The condensate water outlets of the final condensate water preheater 4 and the live steam condensate water preheater 3 are connected with the absorption heat pump 5, and the condensate water is led into the absorption heat pump 5, so that the latent heat of the condensate water can be further recovered and utilized.

[0050] In this embodiment, the system further comprises a heat utilization end 6, which is connected with the hot water outlet of the absorption heat pump 5. The waste heat of the evaporation system absorbed by the absorption heat pump 5 can be used for heating or domestic hot water demand of the heat utilization end 6, and the waste heat generated by the absorption heat pump 5 is connected to the next process or discharged.

[0051] From the perspective of energy balance, the heat loss in the multi-effect evaporation process is not much, in addition to the container surface heat dissipation and material heating, there is basically no other heat loss. Due to the heat pump system's heat function, under the premise of consuming a steam, it can generate 1.5-2.5 parts of heat, so compared with the system before the transformation, the new system increases 0.5-1.5 parts of heat, in the case of heat use outside, using the same volume of live steam, it can not only meet the process operation of the system, but also output heat to the external system, achieving the effect of waste heat recovery and reuse.

[0052] Example 3

[0053] As Figure 3 shown, the present embodiment provides an evaporation system combined with waste heat recovery and utilization technology, comprising: a plurality of heating devices connected in sequence, a plurality of evaporation chambers and an absorption heat pump 5, in the present embodiment, the heating devices are a first-effect heater 101, a second-effect heater 102 and a last-effect heater 103 in sequence, and the evaporation chambers are a first-effect evaporation chamber 201, a second-effect evaporation chamber 202 and a last-effect evaporation chamber 203 in sequence, wherein live steam is introduced into the first-effect heater 101 as an evaporation heat source, and in the present embodiment, the material to be treated is high-salt wastewater, which is preheated twice in the last-effect condensate preheater 4 and the live steam condensate preheater 3, and then introduced into the tube side of the first-effect evaporation chamber 201 under the action of a circulating pump, and the live steam is reduced in pressure to heat the high-salt wastewater in the tube side, the first-effect heater 101 is connected with the live steam condensate preheater 3, and the live steam is condensed into water to serve as a heat source for the first-effect condensate preheater 3 to preheat the high-salt wastewater, thereby fully utilizing the latent heat of the live steam; the first-effect evaporation chamber 201 is connected with the second-effect heater 102 of the next stage, the secondary steam generated in the first-effect evaporation chamber 201 enters the second-effect heater 102 to serve as a heat source for heating the second-effect evaporation chamber 202, the second-effect evaporation chamber 202 is connected with the last-effect heater 103 of the next stage, and so on, and the first-effect evaporation chamber 201, the second-effect evaporation chamber 202 and the third-effect evaporation chamber 203 are connected through balance pipes, and the last-effect evaporation chamber 203 is connected with the absorption heat pump 5.

[0054] The treatment process of the material in the evaporation system is as follows: the high-salt wastewater material first enters the first-effect evaporation chamber 201, continuously evaporates in the first-effect evaporation chamber 201, and the concentration of the material remains basically unchanged; the material in the first-effect evaporation chamber 201 is transferred into the second-effect evaporation chamber 202 under the action of a negative pressure controlled by an automatic valve, and further evaporates in the second-effect evaporation chamber 202 before being transferred into the last-effect evaporation chamber 203. The absorption heat pump 5 is connected with the last-effect evaporation chamber 203, and the secondary steam in the last-effect evaporation chamber 203 can be introduced into the absorption heat pump 5 as a waste heat source to be absorbed and utilized, and the heated circulating fluid of the absorption heat pump 5 is used for heating sections of other process flows or for meeting the demand for domestic heat.

[0055] The working process of live steam is as follows: the live steam is depressurized by the first-effect heater 101 and enters the shell side of the first-effect evaporation chamber 201 to be heated for evaporation; the secondary steam generated by the first-effect evaporation chamber 201 enters the shell side of the second-effect evaporation chamber 202 to be heated for the second-effect evaporation; in this way, the secondary steam generated by the second-effect evaporation chamber 202 enters the shell side of the last-effect evaporation chamber 203 to be heated for the last-effect evaporation; the secondary steam generated by the last-effect is partly used for preheating the feed and is mostly used as a waste heat source in the absorption heat pump 5. In this process, the live steam condensate is connected by pipelines to enter the shell side of the second-effect evaporation chamber 202, the secondary steam condensate is connected by pipelines to enter the shell side of the last-effect evaporation chamber 203, and the last-effect evaporation chamber 203 condensate enters the condensate tank and is then pumped out of the system.

[0056] In this embodiment, the second-effect heater 102 and the last-effect heater 103 connected to the last-effect condensate preheater 4 are used to heat the secondary steam condensate and preheat the material, so that the latent heat of the secondary steam is fully utilized.

[0057] In this embodiment, a part of the live steam is extracted and used as a main heat source in the absorption heat pump 5. The condensate outlets of the last-effect condensate preheater 4 and the live steam condensate preheater 3 are connected to the absorption heat pump 5, the first-effect evaporation chamber 201 and the second-effect evaporation chamber 202 are connected to the absorption heat pump 5, and the condensate in the last-effect condensate preheater 4 and the live steam condensate preheater 3 can be connected to the absorption heat pump 5, so that the latent heat of the condensate can be further recovered and utilized, and when needed, the secondary steam in the first-effect evaporation chamber 201 and the second-effect evaporation chamber 202 can be directly extracted and supplied to the absorption heat pump 5 for use.

[0058] In this embodiment, the system is also configured with an external heat source input, and the external heat source is hot water. The absorption heat pump 5 is connected to the second-effect heater 102 and the last-effect heater 103 by pipelines, and hot water can be supplied to the evaporation system through the pipelines as a part of the heating heat source. The hot water in the absorption heat pump 5 can be supplied to the live steam, so that the extraction of the live steam is reduced, and the waste heat generated by the absorption heat pump 5 can be used in the next process or discharged.

[0059] The embodiment recovers the waste heat of the secondary steam and condensate water by introducing the absorption heat pump 5, indirectly reduces the use of live steam, and directly reduces the extraction of live steam by supplementing external hot water. From the perspective of energy balance, the heat loss in the multi-effect evaporation process is not much, and there is basically no other heat loss except the heat loss of the container surface and the heating of the material. Due to the heating function of the heat pump system, 1.5-2.5 parts of heat can be generated under the premise of consuming one part of steam, so compared with the system before the transformation, the new system increases 0.5-1.5 parts of heat. In the case of using heat externally, the same volume of live steam can be used to meet the process operation of the system, output heat to the external system, or introduce external heat source to supplement the system, achieving the effect of waste heat recovery and reuse, and making the system have input and output functions.

[0060] Embodiment 4

[0061] As shown in Figure 4 , the embodiment provides an evaporation system combined with waste heat recovery and utilization technology, comprising: a plurality of heaters connected in sequence, a plurality of evaporation chambers, and an absorption heat pump. In the embodiment, the heaters are a one-effect heater 101, a two-effect heater 102, and a final-effect heater 103 in sequence, and the evaporation chambers are a one-effect evaporation chamber 201, a two-effect evaporation chamber 202, and a final-effect evaporation chamber 203 in sequence. The one-effect heater 101 is connected to the live steam condensate preheater 3, and the live steam condensate preheater 3 is connected to the one-effect heater 101. The high-salt wastewater is preheated in the final-effect condensate preheater 4 and the live steam condensate preheater 3 in sequence, and then enters the tube side of the one-effect evaporation chamber 201 under the action of the circulating pump. The live steam is condensed into water after being heated in the one-effect heater 101, and the water is used as a heat source for the one-effect condensate preheater 3 to preheat the high-salt wastewater, thereby fully utilizing the latent heat of the live steam. The one-effect evaporation chamber 201 is connected to the two-effect heater 102 of the next stage, and the secondary steam generated in the one-effect evaporation chamber 201 enters the two-effect heater 102 as a heat source to heat the two-effect evaporation chamber 202. The two-effect evaporation chamber 202 is connected to the final-effect heater 103 of the next stage, and so on. The one-effect evaporation chamber 201, the two-effect evaporation chamber 202, and the three-effect evaporation chamber 203 are connected by balance pipes, and the final-effect evaporation chamber 203 is connected to the absorption heat pump 5 through the secondary steam condenser 7.

[0062] The processing flow of the material in the evaporation system is as follows: the high-salinity wastewater material first enters the first-effect evaporation chamber 201, continuously evaporates in the first-effect evaporation chamber 201, and the concentration of the material remains basically unchanged; the material in the first-effect evaporation chamber 201 is transferred into the second-effect evaporation chamber 202 under the action of negative pressure and controlled by an automatic valve, and is further evaporated in the second-effect evaporation chamber 202 and then transferred into the last-effect evaporation chamber 203. The last-effect evaporation chamber 203 is connected with the absorption heat pump 5 through the secondary steam condenser 7, and the secondary steam in the last-effect evaporation chamber 203 is first condensed in the secondary steam condenser 7, and the steam condensate water flows into the absorption heat pump 5 to be used as a waste heat source of the absorption heat pump 5, is absorbed and utilized, and the circulating fluid heated in the absorption heat pump 5 is used for heating sections of other process flows or is used to meet the demand for domestic heat.

[0063] The working flow of the live steam is as follows: the live steam enters the shell side of the first-effect evaporation chamber 201 for the evaporation process after being reduced in pressure by the first-effect heater 101; the secondary steam generated by the first-effect evaporation chamber 201 enters the shell side of the second-effect evaporation chamber 202 for the second-effect evaporation process; in this way, the secondary steam generated by the second-effect evaporation chamber 202 enters the shell side of the last-effect evaporation chamber 203 for the last-effect evaporation process; a small part of the secondary steam generated by the last-effect evaporation chamber is used for preheating of the feed, and most of the secondary steam is first condensed in the secondary steam condenser 7, and the condensate water enters the absorption heat pump 5 to be used as a waste heat source, is absorbed and utilized. In this process, the first-effect live steam condensate water enters the shell side of the second-effect evaporation chamber 202 through a pipeline, the second-effect steam condensate water enters the shell side of the last-effect evaporation chamber 203 through a pipeline, and the last-effect evaporation chamber 203 condensate water enters a condensate water tank and is then pumped out of the system by a condensate water pump.

[0064] In this embodiment, the secondary steam condenser 7 is connected with a vacuum system, the vacuum system draws off the uncondensed gas generated in the evaporation system, and the secondary steam condenser 7 and each evaporation chamber are kept in a negative pressure state, thereby improving the evaporation efficiency of the evaporation system. Under the action of negative pressure, the secondary steam generated by the wastewater in the third-effect evaporation chamber 203 automatically enters the secondary steam condenser 7, is rapidly converted into condensate water under the cooling of circulating cooling water, enters a condensate water tank, and then flows to the absorption heat pump 5.

[0065] In this embodiment, the second-effect heater 102 and the last-effect heater 103 located at the lower level thereof are connected with the last-effect condensate water preheater 4, and the secondary steam condensed therein enters the last-effect condensate water preheater 4 to be used for preliminary preheating of the material, thereby fully utilizing the latent heat of the secondary steam.

[0066] In this embodiment, a part of the live steam is extracted and connected to the absorption heat pump 5 as a main heat source. The condensate water outlets of the last-effect condensate water preheater 4 and the live steam condensate water preheater 3 are connected with the absorption heat pump 5, and the condensate water enters the absorption heat pump 5, so that the latent heat of the condensate water can be further recovered and utilized.

[0067] In this embodiment, the condensate in the last-effect condensate preheater 4 and the live steam condensate preheater 3 can be introduced into the absorption heat pump 5, and the latent heat of the condensate can be further recovered. The double-effect evaporation chamber 202 and the last-effect evaporation chamber 203 are in bidirectional communication with the absorption heat pump 5. When necessary, the secondary steam in the double-effect evaporation chamber 202 and the last-effect evaporation chamber 203 can be directly extracted and supplied to the absorption heat pump 5 for use. The hot water produced by the absorption heat pump 5 after absorbing the system waste heat can also be directly supplemented into the double-effect evaporation chamber 202 and the last-effect evaporation chamber 203 as an evaporation heat source. The waste heat of the absorption heat pump 5 is connected to the next process or discharged externally.

[0068] From the perspective of energy balance, the heat loss in the multi-effect evaporation process is not much. In addition to the heat loss of the container surface and the heating of the material, there is basically no other heat loss. Due to the heating function of the heat pump system, 1.5-2.5 portions of heat can be generated under the premise of consuming one portion of steam. Therefore, compared with the system before the transformation, the new system increases 0.5-1.5 portions of heat. In the case of using heat externally, the same volume of live steam can be used to meet the process operation of the system and output heat to the external system, achieving the effect of waste heat recovery and reuse.

[0069] Embodiment 5

[0070] As shown in Figure 5 The embodiment provides an evaporation system combined with waste heat recovery and utilization technology, which comprises a plurality of heaters connected in sequence, a plurality of evaporation chambers, and an absorption heat pump 5. In this embodiment, the heaters are a first-effect heater 101, a double-effect heater 102, and a last-effect heater 103 in sequence, and the evaporation chambers are a first-effect evaporation chamber 201, a double-effect evaporation chamber 202, and a last-effect evaporation chamber 203 in sequence. The first-effect heater 101 is connected to the live steam as an evaporation heat source. In this embodiment, the material to be treated is high-salt wastewater. The high-salt wastewater is preheated in the last-effect condensate preheater 4 and the live steam condensate preheater 3 in sequence, and then introduced into the tube side of the first-effect evaporation chamber 201 under the action of a circulating pump. The live steam is reduced in pressure and heats the high-salt wastewater in the tube side. The first-effect heater 101 is connected to the live steam condensate preheater 3. The live steam condenses into water and serves as a heat source for the first-effect condensate preheater 3 to preheat the high-salt wastewater, thereby fully utilizing the latent heat of the live steam. The first-effect evaporation chamber 201 is connected to the double-effect heater 102 of the next stage. The secondary steam generated in the first-effect evaporation chamber 201 enters the double-effect heater 102 as a heat source to heat the double-effect evaporation chamber 202. The double-effect evaporation chamber 202 is connected to the last-effect heater 103 of the next stage. The arrangement is repeated in this way. The first-effect evaporation chamber 201, the double-effect evaporation chamber 202, and the last-effect evaporation chamber 203 are connected through balance pipes. The last-effect evaporation chamber 203 is connected to the absorption heat pump 5.

[0071] The treatment process of the material in the evaporation system is as follows: the high-salinity wastewater material first enters the first-effect evaporation chamber 201, continuously evaporates in the first-effect evaporation chamber 201, and the concentration of the material remains basically unchanged; the material in the first-effect evaporation chamber 201 is transferred into the second-effect evaporation chamber 202 under the action of negative pressure and controlled by an automatic valve, and after further evaporation in the second-effect evaporation chamber 202, is also transferred into the last-effect evaporation chamber 203. The absorption heat pump 5 is connected with the last-effect evaporation chamber 203, and the secondary steam in the last-effect evaporation chamber 203 can enter the absorption heat pump 5 as a waste heat source and be absorbed and utilized, and the circulating fluid heated by the absorption heat pump 5 is used for heating sections of other process flows or used to meet the demand for domestic heat.

[0072] The working process of the live steam is as follows: the live steam enters the shell side of the first-effect evaporation chamber 201 after being reduced in pressure by the first-effect heater 101 to heat the evaporation process; the secondary steam generated by the first-effect evaporation chamber 201 enters the shell side of the second-effect evaporation chamber 202 to heat the second-effect evaporation process; in this way, the secondary steam generated by the second-effect evaporation chamber 202 enters the shell side of the last-effect evaporation chamber 203 to heat the last-effect evaporation process; and the secondary steam generated by the last effect is partly used for preheating the feed and is mostly used as a waste heat source in the absorption heat pump 5 and is absorbed and utilized. In this process, the first-effect live steam condensate water enters the shell side of the second-effect evaporation chamber 202 through a pipeline, the second-effect steam condensate water enters the shell side of the last-effect evaporation chamber 203 through a pipeline, and the last-effect evaporation chamber 203 condensate water enters a condensate water tank and is then pumped out of the system by a condensate water pump.

[0073] In this embodiment, the second-effect heater 102 and the last-effect heater 103 located at the lower level thereof are connected with the last-effect condensate water preheater 4, and the secondary steam used for heating in the last-effect condensate water preheater 4 is condensed and enters the last-effect condensate water preheater 4 to preliminarily preheat the material, so as to fully utilize the latent heat of the secondary steam.

[0074] In this embodiment, a part of the live steam is extracted and connected to the absorption heat pump 5 as a main heat source. The condensate water outlets of the last-effect condensate water preheater 4 and the live steam condensate water preheater 3 are connected with the absorption heat pump 5, and the latent heat of the condensate water can be further recovered and utilized.

[0075] In this embodiment, the system is also provided with an external heat source input, and the external heat source adopts hot water. The absorption heat pump 5 is connected with the steam pipelines between the first-effect evaporation chamber 201 and the second-effect heater 102, the steam pipeline between the second-effect evaporation chamber 202 and the last-effect heater 103, and the steam pipelines between the first-effect evaporation chamber 201 and the second-effect heater 102 and between the second-effect evaporation chamber 202 and the last-effect heater 103 through pipelines, can supplement steam into the second-effect heater 102 and the last-effect heater 103, can supplement additional steam into the system when the heat of the secondary steam is insufficient, so as to ensure the normal operation of the evaporation system, and the waste heat generated by the absorption heat pump 5 is connected to the next process or discharged.

[0076] The embodiment indirectly reduces the use of live steam by introducing the absorption heat pump 5 to recover the waste heat of the secondary steam and condensate water, and directly reduces the extraction of live steam by supplementing external hot water. From the perspective of energy balance, the heat loss in the multi-effect evaporation process is not much, and there is basically no other heat loss except the heat loss of the container surface and the material temperature rise. Due to the heat increasing function of the heat pump system, 1.5-2.5 portions of heat can be generated under the premise of consuming one portion of steam, so compared with the system before the modification, the new system increases 0.5-1.5 portions of heat. In the case of using heat externally, the same volume of live steam can be used to meet the process operation of the system and output heat to the external system. In addition, the introduction of the external heat source supplements the system to avoid the lack of secondary steam heat, achieves the effect of waste heat recovery and reuse, and enables the system to have input and output.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An evaporation system incorporating waste heat recovery technology, characterized by, The application relates to a multi-stage absorption heat pump, which comprises a plurality of heating devices connected in sequence, a plurality of evaporation chambers and an absorption heat pump. The first-stage heating device is connected with the fresh steam condensate preheater.

2. The evaporation system combined with the waste heat recovery and utilization technology according to claim 1, characterized in that, The second-stage heating device, the heating device at the next stage and the last-stage heating device are all connected with the last-stage condensate preheater.

3. The evaporation system combined with the waste heat recovery and utilization technology according to claim 1, characterized in that, A part of the fresh steam is extracted and introduced into the absorption heat pump as a main heat source.

4. The evaporation system combined with the waste heat recovery and utilization technology according to claim 1, characterized in that, The condensate outlets of the last-stage condensate preheater and the fresh steam condensate preheater are connected with the absorption heat pump, and the condensate is introduced into the absorption heat pump.

5. The evaporation system combined with the waste heat recovery and utilization technology according to claim 1, characterized in that, The inlet of the absorption heat pump is connected with the evaporation chambers, so that the secondary steam can be extracted and introduced into the absorption heat pump as an auxiliary heat source.

6. The evaporation system in combination with waste heat recovery technology according to claim 4, characterized in that, The waste heat outlet of the absorption heat pump is connected with the heating devices.

7. The evaporation system in combination with waste heat recovery technology according to claim 1, characterized by, The last-stage evaporation chamber is also connected with the absorption heat pump and a secondary steam condenser.

8. The evaporation system in combination with a waste heat recovery technology according to claim 1 or 7, characterized in that, The absorption heat pump is connected with a heat utilization end.

9. The evaporation system in combination with waste heat recovery technology according to claim 1, characterized by, The absorption heat pump is connected with an external input heat source.

10. The evaporation system in combination with waste heat recovery technology according to claim 1, characterized in that, The waste heat of the absorption heat pump is introduced into the next process or discharged.

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