Aniline-thermal power combined energy-saving system and method

Abstract

The present application provides aniline-thermal power combined energy-saving system and energy-saving method. The energy-saving system comprises an aniline unit and a thermal power unit; the aniline unit comprises a fluidized bed reactor, a first steam boiler, a second steam boiler, a hot water heat exchanger, a water cooler, a gas-liquid separation tank, a hot water tank and a first deaerator connected in sequence; the hot water heat exchanger is used for heating water from the hot water tank by using the waste heat in the aniline from the second steam boiler to supply the thermal power unit as a heat medium; the water inlet of the hot water tank is connected to a water outlet pipeline of the thermal power unit for receiving water from the thermal power unit; the thermal power unit comprises a desalted water heat exchanger, a desalted water tank and a second deaerator connected in sequence; the desalted water heat exchanger is used for heating desalted water from the desalted water tank by using the water from the hot water heat exchanger. The energy-saving system and energy-saving method improve the heat utilization rate of the aniline device by combining the aniline device with the thermal power device, thereby achieving energy saving.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical energy saving, and particularly relates to an aniline-thermal power combined energy saving system and method. BACKGROUND

[0002] Aniline is an important organic chemical raw material and an important intermediate in the synthesis of rubber, organic pigments, coatings, dyes and pesticide industries. Due to the wide application of aniline, the market has great potential. At present, the process routes for aniline production mainly include iron powder reduction of nitrobenzene, phenol ammoniation and catalytic hydrogenation of nitrobenzene, which respectively account for 5%, 10% and 85% of the total aniline production capacity. Most companies use the catalytic hydrogenation of nitrobenzene to produce aniline. Three processes, namely fixed bed catalytic hydrogenation, fluidized bed catalytic hydrogenation and nitrobenzene liquid phase hydrogenation, are used in industry, and the catalysts used are copper-based, nickel-based and noble metal palladium, and the catalyst carriers are silica gel, zeolite, activated alumina and diatomite. At present, the production of aniline in China mostly adopts the fluidized bed catalytic hydrogenation process of nitrobenzene, which is a mature technology with obvious technical advantages.

[0003] The catalytic hydrogenation of nitrobenzene is an exothermic reaction, and the reaction formula is as follows:

[0004] C6H5NO2+3H2→C6H5NH2+2H2O+544kJ / mol

[0005] Since the hydrogenation of nitrobenzene is a strong exothermic reaction, the azeotrope of aniline and water overflowing from the top of the reactor is generally at a temperature of about 200-230℃. The traditional process generally needs to use four-stage condensation to cool the high-temperature azeotrope to 40℃. In the four-stage condensation, most of the reaction heat is recovered through a medium-pressure steam generator and a low-pressure steam generator, but the remaining heat is further cooled through an air cooler and a water cooler, resulting in a large amount of heat waste and consumption of a large amount of water cooling circulating water, causing energy waste.

[0006] CN 105418437 A discloses an energy saving method for an aniline device, in which part of the fluidized bed outlet gas phase material of the existing gas phase fluidized bed process aniline device is exchanged through a raw hydrogen gas heat exchanger, condensed through a condenser, and then subjected to gas-liquid separation, hydrogen is separated and reused, and the separated liquid phase material aniline and water are cooled through a cooler and then subjected to aniline and water separation; the other part of the fluidized bed outlet material directly enters a tower type direct heat exchanger and exchanges heat with aniline in the heat exchanger. Although this process achieves energy saving to some extent, the heat utilization rate is still not high, and the equipment requirements are high and the transformation is large.

[0007] The thermoelectric device comprises an ultra-high pressure circulating fluidized bed boiler, a steam turbine and a chemical water system, wherein the steam water system is heated by desalted water provided by the chemical water through a low pressure heater, an oxygen remover and a high pressure heater, steam is generally used to heat the desalted water to a qualified temperature, and then the desalted water enters a coal economizer, a steam drum and a superheater to generate qualified ultra-high pressure steam, and the overall energy level utilization space is large.

[0008] The conventional method of aniline device cannot efficiently utilize the heat carried by the crude aniline at the top of the three-phase fluidized bed reactor, and the aniline device and the thermoelectric device belong to different fields, and there is no report on the combination of aniline and thermoelectricity to realize energy saving. SUMMARY

[0009] The first object of the present application is to provide an aniline-thermoelectric combined energy saving system, which combines the aniline device with the thermoelectric device to improve the heat utilization rate of the aniline device and realize energy saving.

[0010] The second object of the present application is to provide an aniline-thermoelectric combined method using the aforementioned energy saving system, which can combine the aniline device with the thermoelectric device to improve the heat utilization rate of the aniline device and realize energy saving.

[0011] In order to achieve the first object of the present application, the following technical solutions are adopted:

[0012] An aniline-thermoelectric combined energy saving system, comprising an aniline unit and a thermoelectric unit;

[0013] The aniline unit comprises a fluidized bed reactor, a first steam boiler, a second steam boiler, a hot water heat exchanger, a water cooler, a gas-liquid separation tank, a hot water tank and a first oxygen remover connected by material pipelines; wherein,

[0014] The fluidized bed reactor is used for catalytic hydrogenation reaction of nitrobenzene, and aniline is output from the top gas phase outlet;

[0015] The first steam boiler is connected to the top gas phase outlet of the fluidized bed reactor, and is used for generating S10 steam by utilizing the heat in the aniline from the fluidized bed reactor;

[0016] The second steam boiler is connected to the aniline outlet of the first steam boiler, and is used for generating S4 steam by utilizing the residual heat in the aniline from the first steam boiler;

[0017] The aniline inlet of the hot water heat exchanger is connected to the aniline outlet of the second steam boiler, and the water inlet of the hot water heat exchanger is connected to the water outlet of the hot water tank, which is used for heating the water from the hot water tank by utilizing the residual heat in the aniline from the second steam boiler to supply the thermoelectric unit as a heat medium;

[0018] The first deaerator is connected to the water inlets of the first steam boiler and the second steam boiler respectively, for deaerating the input desalinated water and then delivering the deaerated water into the first steam boiler and the second steam boiler respectively as the water input;

[0019] One end of the water cooler is connected to the aniline outlet of the hot water heat exchanger, and the other end is connected to the gas-liquid separation tank, for further cooling the aniline from the hot water heat exchanger and then sending it to the gas-liquid separation tank through an aniline outlet pipeline for gas-liquid separation;

[0020] The water inlet of the hot water tank is connected to the water outlet pipeline of the thermoelectric unit, for receiving water from the thermoelectric unit;

[0021] The thermoelectric unit comprises a desalinated water heat exchanger, a desalinated water tank and a second deaerator connected through pipelines, wherein,

[0022] The water outlet of the desalinated water tank is connected to the desalinated water passage inlet of the desalinated water heat exchanger, for storing desalinated water to supply the desalinated water heat exchanger;

[0023] The desalinated water passage inlet of the desalinated water heat exchanger is connected to the desalinated water tank, and the hot medium passage inlet of the desalinated water heat exchanger is connected to the water outlet of the hot water heat exchanger, for heating the desalinated water from the desalinated water tank with the water from the hot water heat exchanger;

[0024] The second deaerator is provided with a steam inlet and a desalinated water inlet, and the steam inlet is connected to a steam feeding pipeline, and the desalinated water inlet is connected to the desalinated water passage outlet of the desalinated water heat exchanger, for inputting S10 steam and desalinated water from the desalinated water heat exchanger respectively, deaerating the input desalinated water, and then outputting the deaerated water through a second deaerator water outlet pipeline;

[0025] The second deaerator is provided with a desalinated water inlet and a steam inlet; the desalinated water inlet is connected to the desalinated water passage outlet of the desalinated water heat exchanger, for inputting desalinated water from the desalinated water heat exchanger; and the steam inlet is connected to a steam feeding pipeline, for inputting S10 steam to deaerate the input desalinated water.

[0026] Preferably, the aniline unit further comprises a preheater, which is arranged on the material pipeline from the second steam boiler to the hot water heat exchanger, and the water inlet end of the preheater is connected to the first deaerator, and the water outlet end is connected to the water inlets of the first steam boiler and the second steam boiler respectively, for preheating the water from the first deaerator with the residual heat in the aniline from the second steam boiler to supply the first steam boiler and the second steam boiler.

[0027] Preferably, the thermoelectric unit further comprises a user, a water inlet of the user being connected to an outlet of the hot medium channel of the desalted water heat exchanger for outputting water from the desalted water heat exchanger as a hot medium and heat therein.

[0028] Preferably, the thermoelectric unit further comprises a seawater cooler, a water inlet of the seawater cooler being connected to a water outlet of the user for further cooling water from the user with seawater as a cold medium and outputting the water through an outlet pipeline;

[0029] Preferably, a first valve is arranged on a seawater inlet pipeline of the seawater cooler; the thermoelectric unit further comprises a first temperature indicating control device, one end of which is connected to the outlet pipeline and the other end of which is connected to the first valve, for indicating the temperature of the material in the outlet pipeline and controlling the opening of the first valve according to the temperature indication; and / or

[0030] A first temperature indicating device is arranged on a second pipeline from the desalted water heat exchanger to the second deaerator, for indicating the temperature of the material in the second pipeline; and / or

[0031] A second valve is arranged on the steam inlet pipeline; the thermoelectric unit further comprises a second temperature indicating control device, one end of which is connected to the outlet pipeline of the second deaerator and the other end of which is connected to the second valve, for indicating the temperature of the material in the outlet pipeline of the second deaerator and controlling the opening of the second valve according to the temperature indication.

[0032] Preferably, the aniline unit further comprises an air cooler, a water inlet end of the air cooler being connected to the outlet pipeline of the thermoelectric unit and a water outlet end of the air cooler being connected to the water inlet of the hot water tank, for further cooling the outlet water from the thermoelectric unit and outputting the water to the hot water tank;

[0033] Preferably, a third valve is arranged on a third pipeline from the air cooler to the hot water tank, and a first pressure indicating control device is arranged in parallel from the third valve to the water inlet end of the third valve, for indicating the pressure of the material in the third pipeline and controlling the opening of the third valve according to the pressure indication; and / or

[0034] A fourth valve is arranged on the water inlet pipeline of the air cooler; the aniline unit further comprises a third temperature indicating control device, one end of which is connected to the third pipeline and the other end of which is connected to the fourth valve, for indicating the temperature of the material in the third pipeline and controlling the opening of the fourth valve according to the temperature indication; and / or

[0035] The water inlet pipe of the hot water heat exchanger is provided with a fifth valve, and a first flow indicating control device is connected in parallel from the fifth valve to the water outlet end of the fifth valve, for indicating the flow of material in the water inlet pipe and controlling the opening of the fifth valve according to the flow indication.

[0036] The cold medium feed pipe of the water cooler is provided with a sixth valve, and the aniline unit further comprises a fourth temperature indicating control device, one end of which is connected to the aniline outlet pipe and the other end is connected to the sixth valve, for indicating the temperature of material in the aniline outlet pipe and controlling the opening of the sixth valve according to the temperature indication.

[0037] To achieve the second object of the present application, an aniline-thermal power combined energy saving method using the above-mentioned energy saving system is provided, comprising:

[0038] The aniline output from the fluidized bed reactor in the aniline unit is sequentially subjected to energy utilization by the first steam boiler, the second steam boiler and the hot water heat exchanger, thereby sequentially generating S10 steam, S4 steam and hot water for the post-cooling of the thermal power unit;

[0039] The hot water from the hot water heat exchanger in the aniline unit is input into the thermal power unit, and is used as a heat medium of the desalted water heat exchanger to preheat the desalted water from the desalted water tank, the preheated desalted water is sent to the second deaerator for deaeration, and the hot water from the aniline unit is output to the hot water tank in the aniline unit for circulation after heat exchange and cooling.

[0040] Preferably, the aniline unit further comprises a preheater, which is arranged on the material pipeline from the second steam boiler to the hot water heat exchanger, and the water inlet end of the preheater is connected to the first deaerator, and the water outlet end of the preheater is respectively connected to the water inlets of the first steam boiler and the second steam boiler;

[0041] The energy saving method further comprises:

[0042] The aniline from the second steam boiler is first subjected to energy utilization by the preheater to preheat the water from the first deaerator, and then is supplied to the first steam boiler and the second steam boiler, and the aniline after heat exchange and cooling is used as a heat medium of the hot water heat exchanger for energy utilization.

[0043] Preferably, the thermal power unit further comprises a user, and the water inlet of the user is connected to the heat medium passage outlet of the desalted water heat exchanger;

[0044] The energy saving method further comprises:

[0045] The water from the desalted water heat exchanger as a heat medium is delivered to the user for use.

[0046] Preferably, the thermoelectric unit further comprises a seawater cooler, and a water inlet of the seawater cooler is connected to a water outlet of the user;

[0047] The energy-saving method further comprises:

[0048] The water outlet of the user is sent to the seawater cooler for further cooling and then output to the hot water tank in the aniline unit for circulation.

[0049] Preferably, a first valve is arranged on a seawater inlet pipeline of the seawater cooler; the thermoelectric unit further comprises a first temperature indication control device, one end of which is connected to the water outlet pipeline and the other end of which is connected to the first valve;

[0050] The energy-saving method further comprises:

[0051] The first temperature indication control device is used to indicate the temperature of the material in the water outlet pipeline, and the opening degree of the first valve is controlled according to the temperature indication.

[0052] Preferably, a first temperature indication device is arranged on a second pipeline from the desalted water heat exchanger to the second deaerator;

[0053] The energy-saving method further comprises:

[0054] The first temperature indication device is used to indicate the temperature of the material in the second pipeline.

[0055] Preferably, a second valve is arranged on the steam feeding pipeline; the thermoelectric unit further comprises a second temperature indication control device, one end of which is connected to the water outlet pipeline of the second deaerator and the other end of which is connected to the second valve;

[0056] The energy-saving method further comprises:

[0057] The second temperature indication control device is used to indicate the temperature of the material in the water outlet pipeline of the second deaerator, and the opening degree of the second valve is controlled according to the temperature indication.

[0058] Preferably, the aniline unit further comprises an air cooler, a water inlet end of which is connected to the water outlet pipeline of the thermoelectric unit and a water outlet end of which is connected to the water inlet of the hot water tank, for further cooling the water outlet from the thermoelectric unit and then outputting the water to the hot water tank;

[0059] The energy-saving method further comprises:

[0060] The water outlet from the thermoelectric unit is sent to the air cooler for further cooling and then output to the hot water tank for circulation;

[0061] Preferably, a third valve is arranged on the third pipeline from the air cooler to the hot water tank, and a first pressure indicating control device is arranged in parallel from the third valve to the water inlet end of the third valve;

[0062] The energy saving method further comprises:

[0063] The first pressure indicating control device is used to indicate the pressure of the material in the third pipeline and control the opening of the third valve according to the pressure indication;

[0064] Preferably, a fourth valve is arranged on the water inlet pipeline of the air cooler; the aniline unit further comprises a third temperature indicating control device, one end of which is connected to the third pipeline and the other end of which is connected to the fourth valve;

[0065] The energy saving method further comprises:

[0066] The third temperature indicating control device is used to indicate the temperature of the material in the third pipeline and control the opening of the fourth valve according to the temperature indication;

[0067] Preferably, a fifth valve is arranged on the water inlet pipeline of the hot water heat exchanger, and a first flow indicating control device is arranged in parallel from the fifth valve to the water outlet end of the fifth valve;

[0068] The energy saving method further comprises:

[0069] The first flow indicating control device is used to indicate the flow of the material in the water inlet pipeline and control the opening of the fifth valve according to the flow indication;

[0070] Preferably, a sixth valve is arranged on the cold medium feed pipeline of the water cooler; the aniline unit further comprises a fourth temperature indicating control device, one end of which is connected to the aniline outlet pipeline and the other end of which is connected to the sixth valve;

[0071] The energy saving method further comprises:

[0072] The fourth temperature indicating control device is used to indicate the temperature of the material in the aniline outlet pipeline and control the opening of the sixth valve according to the temperature indication.

[0073] The beneficial effects of the present application are:

[0074] (1)the conventional method is difficult to efficiently utilize the energy of the aniline material at the top of the fluidized bed reactor in the aniline device, the present application increases a large amount of steam by utilizing the method for generating steam for the first steam boiler and the second steam boiler and preheating the water inlet of the first steam boiler and the second steam boiler, and the heat utilization rate of the aniline unit is improved to the highest degree by utilizing the remaining heat to produce high-temperature hot water for the heat and power unit, thereby saving the circulating water consumption of the aniline unit and the steam consumption of the heat and power unit, and the devices of the two units achieve a win-win effect; by using the energy-saving system and the energy-saving method of the present application, 20 million tons / year of aniline device can recover heat of 13.8-18 MW, at least 0.16 tons of steam / ton of aniline (aniline output is 4 tons / hour) is increased, the heat and power unit can save S10 steam 15.5-20.2 tons / hour, and the heat utilization rate of the aniline unit is as high as 90% or more, while the circulating water consumption of the aniline unit is also saved;

[0075] (2)the aniline energy utilization rate in the present application is high, and through linkage with heat for the heat and power, the energy consumption of the two devices can be reduced, and the aniline energy utilization rate is at an advanced level in the industry;

[0076] (3)the present application converts low-quality heat into high-quality steam by preheating the water inlet of the steam boiler, thereby significantly improving the steam output of the aniline unit;

[0077] (4)the present application guarantees stable operation of the energy-saving system through buffering and adjustment of the seawater plate exchanger in the hot water tank, the air cooler and the seawater cooler, and does not have a negative impact on the normal operation of the two-unit device;

[0078] (5)the present application can maximize the recovery and utilization of heat through multi-stage heat extraction at the heat extraction end and multi-stage heat utilization at the heat utilization end, and realizes the matching of heat production and utilization levels;

[0079] (6)the present application fully utilizes the latent heat and sensible heat of crude aniline, uses desalted water and hot water as media, improves the steam output of the aniline unit, reduces the steam consumption of the heat and power unit, guarantees the stability of the energy-saving system through equipment buffering and adjustment, realizes the purpose of heat recovery and energy consumption reduction, and has good economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0080] Figure 1 is a structural schematic diagram of the aniline-heat and power combined energy-saving system of the present application in an embodiment;

[0081] Figure 2 is a partial detail view of Figure 1 ;

[0082] Figure 3 is a process flow diagram of comparative example 1;

[0083] Wherein, the PW water is desalinated water, the BFW water is boiler water, S4 is S4 steam, S4C is S4 steam condensate, and S10 is S10 steam. DETAILED DESCRIPTION

[0084] The technical solutions of the present application and their effects are further described below in combination with specific embodiments / examples. The following embodiments / examples are only used to illustrate the content of the present application, and the present application is not limited to the following embodiments / examples. Simple changes made to the present application using the concept of the present application are within the scope of the present application.

[0085] As shown in Figure 1 , an aniline-thermal power combined energy-saving system includes an aniline unit 1 and a thermal power unit 2;

[0086] The aniline unit 1 includes a fluidized bed reactor 101, a first steam boiler 102, a second steam boiler 103, a hot water heat exchanger 104, a water cooler 105, a gas-liquid separation tank 106, a hot water tank 107, and a first deaerator 108 connected by material pipelines; wherein,

[0087] The fluidized bed reactor 101 is used for catalytic hydrogenation reaction of nitrobenzene to generate aniline from the top gas phase outlet;

[0088] The first steam boiler 102 is connected to the top gas phase outlet of the fluidized bed reactor 101, and is used for generating S10 steam by using the heat in the aniline from the fluidized bed reactor 101;

[0089] The second steam boiler 103 is connected to the aniline outlet of the first steam boiler 102, and is used for generating S4 steam by using the waste heat in the aniline from the first steam boiler 102;

[0090] The aniline inlet of the hot water heat exchanger 104 is connected to the aniline outlet of the second steam boiler 103, and the water inlet of the hot water heat exchanger 104 is connected to the water outlet of the hot water tank 107, and is used for heating the water from the hot water tank 107 by using the waste heat in the aniline from the second steam boiler 103 to supply the thermal power unit 2 as a heat medium;

[0091] The first deaerator 108 is connected to the water inlets of the first steam boiler 102 and the second steam boiler 103, respectively, and is used for deaerating the input desalinated water and then delivering the deaerated desalinated water to the first steam boiler 102 and the second steam boiler 103 as water;

[0092] One end of the water cooler 105 is connected to the aniline outlet of the hot water heat exchanger 104, and the other end is connected to the gas-liquid separation tank 106, for further cooling of the aniline from the hot water heat exchanger 104, and then sending to the gas-liquid separation tank 106 through the aniline outlet pipeline 111 for gas-liquid separation;

[0093] The water inlet of the hot water tank 107 is connected to the water outlet pipeline of the thermoelectric unit 2, for receiving water from the thermoelectric unit 2;

[0094] The thermoelectric unit 2 comprises a desalted water heat exchanger 201, a desalted water tank 202 and a second deaerator 203 connected by a material pipeline; wherein,

[0095] The water outlet of the desalted water tank 202 is connected to the desalted water passage inlet of the desalted water heat exchanger 201, for storing desalted water for the desalted water heat exchanger 201;

[0096] The desalted water passage inlet of the desalted water heat exchanger 201 is connected to the desalted water tank 202, and the heat medium passage inlet of the desalted water heat exchanger 201 is connected to the water outlet of the hot water heat exchanger 104, for heating the desalted water from the desalted water tank 202 by using water from the hot water heat exchanger 104;

[0097] The second deaerator 203 is provided with a steam inlet and a desalted water inlet, and the steam inlet is connected to the steam feeding pipeline 206, and the desalted water inlet is connected to the desalted water passage outlet of the desalted water heat exchanger 201, for respectively introducing S10 steam and desalted water from the desalted water heat exchanger 201, and then outputting the desalted water after deaeration through the second deaerator water outlet pipeline 214;

[0098] The second deaerator 203 is provided with a desalted water inlet and a steam inlet; and the desalted water inlet is connected to the desalted water passage outlet of the desalted water heat exchanger 201, for introducing desalted water from the desalted water heat exchanger 201; and the steam inlet is connected to the steam feeding pipeline 206, for introducing S10 steam to deaerate the introduced desalted water.

[0099] The energy-saving system of the present application solves the problem of efficient utilization of the energy in the aniline material at the top of the fluidized bed reactor in the aniline unit by combining the aniline unit and the thermoelectric unit, and by adding the hot water heat exchanger 104 and the hot water tank 107 in the aniline unit, the heat in the aniline at the top of the fluidized bed reactor of the aniline unit is used to generate steam for the first steam boiler and the second steam boiler and to preheat the water into the first steam boiler and the second steam boiler, a large amount of steam is generated, and the remaining heat is used to generate high-temperature hot water through the hot water heat exchanger for the thermoelectric unit, the steam input amount of the second deaerator 203 is reduced, energy is saved, and the heat utilization rate of the aniline unit is maximized; and the water from the thermoelectric unit is sent into the hot water tank 107 of the aniline unit for buffering and then into the hot water heat exchanger 104 for heating, forming a hot water circulation, and reducing the water consumption of the thermoelectric unit.

[0100] The first steam boiler 102 and the second steam boiler 103 are boilers commonly used in the art, as understood by a person skilled in the art.

[0101] In an embodiment, the outlet water temperature of the hot water heat exchanger 104 is 110-120℃, such as 111℃, 112℃, 113℃, 114℃, 115℃, 116℃, 117℃, 118℃ and 119℃.

[0102] In an embodiment, the inlet water temperature of the hot water heat exchanger 104 is 60-70℃, such as 61℃, 62℃, 63℃, 64℃, 65℃, 66℃, 67℃, 68℃ and 69℃.

[0103] In an embodiment, the outlet water temperature of the hot water tank 107 is 60-70℃, such as 61℃, 62℃, 63℃, 64℃, 65℃, 66℃, 67℃, 68℃ and 69℃.

[0104] In an embodiment, the buffering time of the hot water tank 107 for the inlet water is 0.5-2h, such as 1h and 1.5h.

[0105] In an embodiment, the desalinated water temperature from the desalinated water tank 202 in the desalinated water heat exchanger 201 is 40-50℃, such as 41℃, 42℃, 43℃, 44℃, 45℃, 46℃, 47℃, 48℃ and 49℃.

[0106] In an embodiment, the temperature of the desalted water from the desalted water tank 202 after heat exchange by the desalted water heat exchanger 201 is 80-100°C, such as 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C and 99°C.

[0107] In an embodiment, the aniline unit 1 further comprises a preheater 109, which is arranged on the material pipeline from the second steam boiler 103 to the hot water heat exchanger 104, and the water inlet end of which is connected to the first deaerator 108, and the water outlet end of which is connected to the water inlets of the first steam boiler 102 and the second steam boiler 103 respectively, for preheating the water from the first deaerator 108 by using the residual heat in the aniline from the second steam boiler 103 to supply the first steam boiler 102 and the second steam boiler 103, so as to increase the water inlet temperature of the first steam boiler 102 and the second steam boiler 103, facilitate to increase the steam production, increase the steam production, and improve the heat utilization rate of the aniline unit.

[0108] Those skilled in the art understand that the hot water heat exchanger 104 is used to preheat the water from the first deaerator 108 by using the aniline from the second steam boiler 103 as the heat medium.

[0109] In an embodiment, the heat and power unit 2 further comprises a user 204, and the water inlet of the user 204 is connected to the outlet of the heat medium channel of the desalted water heat exchanger 201, for further utilizing the water and the heat therein from the desalted water heat exchanger 201 as the heat medium after output, so as to further utilize the water and the heat therein from the desalted water heat exchanger 201 as the heat medium after heat exchange and temperature reduction, and improve the heat utilization rate.

[0110] In an embodiment, the heat and power unit 2 further comprises a seawater cooler 205, and the water inlet of the seawater cooler 205 is connected to the water outlet of the user 204, for further cooling the water from the user 204 by using seawater as the cold medium and then outputting the water through the water outlet pipeline 208, so as to cool the water outlet of the heat and power unit 2 to a specified temperature, so that when the water in the hot water tank 107 is introduced into the hot water heat exchanger 104 to continue heating by using aniline as the heat medium, the influence of the fluctuation of the hot water flow on the energy-saving system can be reduced, and the water in the hot water tank 107 is introduced into the hot water heat exchanger 104 to continue heating by using aniline as the heat medium, thereby forming a closed hot water circulation.

[0111] In one embodiment, a first valve 207 is arranged on the seawater inlet pipeline of the seawater cooler 205; the thermoelectric unit 2 further comprises a first temperature indicating control device 209, one end of which is connected to the outlet pipeline 208 and the other end of which is connected to the first valve 207, for indicating the temperature of the material in the outlet pipeline 208 and controlling the opening of the first valve 207 according to the temperature indication, so as to adjust and control the temperature of the material in the outlet pipeline 208.

[0112] In one embodiment, a first temperature indicating device 212 is arranged on the second pipeline 211 from the desalted water heat exchanger 201 to the second deaerator 203, for indicating the temperature of the material in the second pipeline 211.

[0113] In one embodiment, a second valve 213 is arranged on the steam inlet pipeline 206; the thermoelectric unit 2 further comprises a second temperature indicating control device 216, one end of which is connected to the second deaerator outlet pipeline 214 and the other end of which is connected to the second valve 213, for indicating the temperature of the material in the second deaerator outlet pipeline 214 and controlling the opening of the second valve 213 according to the temperature indication, so as to adjust and control the temperature of the material in the second deaerator outlet pipeline 214.

[0114] In one embodiment, the aniline unit 1 further comprises an air cooler 110, the inlet end of which is connected to the outlet pipeline of the thermoelectric unit 2 and the outlet end of which is connected to the inlet of the hot water tank 107, for further cooling the outlet water from the thermoelectric unit 2 and outputting the water to the hot water tank 107, so as to further cool the inlet water of the hot water tank 107 to avoid the influence of temperature fluctuation on the energy-saving system.

[0115] In one embodiment, a third valve 114 is arranged on the third pipeline 113 from the air cooler 110 to the hot water tank 107, and a first pressure indicating control device 115 is arranged in parallel from the third valve 114 to the inlet end of the third valve 114, for indicating the pressure of the material in the third pipeline 113 and controlling the opening of the third valve 114 according to the pressure indication, so as to adjust and control the pressure of the material in the third pipeline 113.

[0116] In one embodiment, a fourth valve 112 is arranged on the inlet pipeline of the air cooler 110; the aniline unit 1 further comprises a third temperature indicating control device 116, one end of which is connected to the third pipeline 113 and the other end of which is connected to the fourth valve 112, for indicating the temperature of the material in the third pipeline 113 and controlling the opening of the fourth valve 112 according to the temperature indication, so as to adjust and control the temperature of the material in the third pipeline 113.

[0117] In an embodiment, the water inlet pipe 117 of the hot water heat exchanger 104 is provided with a fifth valve 118, and a first flow indicating control device 119 is connected in parallel between the fifth valve 118 and the water outlet end of the fifth valve 118, for indicating the flow of the material in the water inlet pipe 117 and controlling the opening of the fifth valve 118 according to the flow indication, so as to adjust and control the flow of the material in the water inlet pipe 117.

[0118] In an embodiment, the cold medium inlet pipe of the water cooler 105 is provided with a sixth valve 120; the aniline unit 1 further comprises a fourth temperature indicating control device 121, one end of which is connected to the aniline outlet pipe 111, and the other end is connected to the sixth valve 120, for indicating the temperature of the material in the aniline outlet pipe 111 and controlling the opening of the sixth valve 120 according to the temperature indication, so as to adjust and control the temperature of the material in the aniline outlet pipe 111.

[0119] The aniline-thermal power combined energy-saving system of the present application can still provide 2h of water supply for the energy-saving system when the heat dissipation devices such as the seawater cooler 205 and the air cooler 110 are all disabled, and provides 2h of reaction time for manual intervention. Through a series of safeguard measures, the aniline-thermal power combined energy-saving can be safely realized, and the operation cost of the two devices can be effectively reduced.

[0120] The present application also provides an aniline-thermal power combined energy-saving method using the above-mentioned energy-saving system, comprising:

[0121] The aniline output from the fluidized bed reactor 101 in the aniline unit 1 is sequentially subjected to energy utilization in the first steam boiler 102, the second steam boiler 103 and the hot water heat exchanger 104, and sequentially generates S10 steam, S4 steam and hot water for post-cooling of the thermal power unit 2;

[0122] The hot water from the hot water heat exchanger 104 in the aniline unit 1 is input into the thermal power unit 2, and is used as a heat medium of the desalted water heat exchanger 201 to preheat the desalted water from the desalted water tank 202, the preheated desalted water is sent to the second deaerator 203 for deaeration, and the hot water from the aniline unit 1 is output to the hot water tank 107 in the aniline unit 1 after heat exchange and cooling for circulation.

[0123] In one embodiment, the aniline unit 1 further comprises a preheater 109, which is arranged in the material pipeline from the second steam boiler 103 to the hot water heat exchanger 104, and the water inlet end of which is connected to the first deaerator 108, and the water outlet end of which is connected to the water inlets of the first steam boiler 102 and the second steam boiler 103 respectively;

[0124] The energy-saving method further comprises:

[0125] The aniline from the second steam boiler 103 is first subjected to energy utilization by the preheater 109 to preheat the water from the first deaerator 108, and then supplied to the first steam boiler 102 and the second steam boiler 103, so as to increase the water inlet temperature of the first steam boiler 102 and the second steam boiler 103, and increase the steam production; meanwhile, the aniline after heat exchange and temperature reduction is used as the heat medium of the hot water heat exchanger 104 to produce high-temperature hot water for the heat and power unit, so as to improve the energy utilization rate.

[0126] In one embodiment, the heat and power unit 2 further comprises a user 204, and the water inlet of the user 204 is connected to the heat medium channel outlet of the desalted water heat exchanger 201;

[0127] The energy-saving method further comprises:

[0128] The water from the desalted water heat exchanger 201 as the heat medium is delivered to the user 204 for use, so as to improve the energy utilization rate, and at the same time, reduce the water outlet temperature of the heat and power unit 2, so that when the water is delivered to the hot water tank 107, the influence of the hot water flow fluctuation on the energy-saving system can be reduced.

[0129] In one embodiment, the heat and power unit 2 further comprises a seawater cooler 205, and the water inlet of the seawater cooler 205 is connected to the water outlet of the user 204;

[0130] The energy-saving method further comprises:

[0131] The water outlet of the user 204 is delivered to the seawater cooler 205 for further temperature reduction, and then output to the hot water tank 107 in the aniline unit 1 for circulation.

[0132] In one embodiment, the seawater inlet pipeline of the seawater cooler 205 is provided with a first valve 207; the heat and power unit 2 further comprises a first temperature indication control device 209, one end of which is connected to the water outlet pipeline 208, and the other end of which is connected to the first valve 207;

[0133] The energy-saving method further comprises:

[0134] The first temperature indicating control device 209 is used to indicate the temperature of the material in the outlet pipeline 208, and the opening of the first valve 207 is controlled according to the temperature indication, so that when the heat removal capacity of the hot end is insufficient, i.e. the temperature of the material in the outlet pipeline 208 is high, the opening of the first valve 207 is increased to increase the seawater plate heat exchange and improve the heat removal capacity.

[0135] In an embodiment, a first temperature indicating device 212 is arranged on the second pipeline 211 from the desalted water heat exchanger 201 to the second deaerator 203.

[0136] The energy saving method further comprises:

[0137] The first temperature indicating device 212 is used to indicate the temperature of the material in the second pipeline 211.

[0138] In an embodiment, a second valve 213 is arranged on the steam feeding pipeline 206; the thermoelectric unit 2 further comprises a second temperature indicating control device 216, one end of which is connected to the second deaerator outlet pipeline 214 and the other end of which is connected to the second valve 213.

[0139] The energy saving method further comprises:

[0140] The second temperature indicating control device 216 is used to indicate the temperature of the material in the second deaerator outlet pipeline 214, and the opening of the second valve 213 is controlled according to the temperature indication, so that when the heat supply of the hot end is insufficient, the S10 steam supplement of the second deaerator 203 can be adjusted by controlling the opening of the second valve 213 to ensure the heat demand.

[0141] In the present application, the hot water heat exchanger 104 and the device and route for removing heat from the aniline material at the front end of the hot water heat exchanger 104 are the hot end, which comprises the hot water heat exchanger 104, the preheater 109, the first steam boiler 102, the second steam boiler 103 and the corresponding aniline material pipeline; the desalted water heat exchanger 201 and the device and route for utilizing the heat in the outlet water of the hot water heat exchanger 104 as a heat medium at the rear end of the desalted water heat exchanger 201 are the heat end, which comprises the desalted water heat exchanger 201, the second deaerator 203, the user 204 and the seawater cooler 205 and the corresponding water flow pipeline.

[0142] In an embodiment, the aniline unit 1 further comprises an air cooler 110, the inlet end of which is connected to the outlet pipeline of the thermoelectric unit 2, and the outlet end of which is connected to the water inlet of the hot water tank 107, which is used to further cool the outlet water from the thermoelectric unit 2 and output to the hot water tank 107.

[0143] The energy saving method further comprises:

[0144] The water from the thermoelectric unit 2 is sent to the air cooler 110 for further cooling and then output to the hot water tank 107 for circulation, ensuring stable operation of the energy-saving system.

[0145] In one embodiment, a third valve 114 is provided on the third pipeline 113 from the air cooler 110 to the hot water tank 107, and a first pressure indicating control device 115 is provided in parallel from the third valve 114 to the water inlet end of the third valve 114;

[0146] The energy-saving method further comprises:

[0147] The first pressure indicating control device 115 is used to indicate the material pressure in the third pipeline 113 and control the opening degree of the third valve 114 according to the aforementioned pressure indication.

[0148] In one embodiment, a fourth valve 112 is provided on the water inlet pipeline of the air cooler 110; the aniline unit 1 further comprises a third temperature indicating control device 116, one end of which is connected to the third pipeline 113 and the other end is connected to the fourth valve 112;

[0149] The energy-saving method further comprises:

[0150] The third temperature indicating control device 116 is used to indicate the material temperature in the third pipeline 113 and control the opening degree of the fourth valve 112 according to the aforementioned temperature indication.

[0151] In one embodiment, a fifth valve 118 is provided on the water inlet pipe 117 of the hot water heat exchanger 104, and a first flow indicating control device 119 is provided in parallel from the fifth valve 118 to the water outlet end of the fifth valve 118;

[0152] The energy-saving method further comprises:

[0153] The first flow indicating control device 119 is used to indicate the material flow in the water inlet pipe 117 and control the opening degree of the fifth valve 118 according to the aforementioned flow indication.

[0154] In one embodiment, a sixth valve 120 is provided on the cold medium feed pipeline of the water cooler 105; the aniline unit 1 further comprises a fourth temperature indicating control device 121, one end of which is connected to the aniline outlet pipeline 111 and the other end is connected to the sixth valve 120;

[0155] The energy-saving method further comprises:

[0156] The fourth temperature indicating control device 121 is used to indicate the temperature of the material in the aniline outlet pipeline 111, and the opening of the sixth valve 120 is controlled according to the temperature indication.

[0157] The aniline-thermal power combined energy-saving device and energy-saving method of the present application greatly improve the energy utilization rate of the aniline unit by preheating the water inlet of the steam boiler and producing high-temperature hot water. Specifically, by preheating the water inlet of the steam boiler, the temperature of the water inlet of the steam boiler can be increased, thereby greatly increasing the steam production; by using the residual heat of the crude aniline to produce high-temperature hot water for the thermal power unit, the amount of circulating water used by the aniline unit and the amount of steam used by the thermal power unit are saved, and the devices of the two units achieve a win-win effect.

[0158] The measurement / calculating method of the relevant parameters in the following examples and comparative examples of the present application is as follows:

[0159] Aniline heat utilization rate: (total heat of aniline at the top of the tower - heat removed by water cooling - heat removed by air cooling) / total heat of aniline at the top of the tower * 100%;

[0160] Profit: (S10 steam production * S10 steam unit price + S4 steam production * S4 steam unit price - air cooling fan power * electricity price + thermal power saved steam * steam unit price) * annual operating time, yuan. (wherein S10 steam unit price is calculated according to 210 yuan / t, S4 steam unit price is calculated according to 145 yuan / t, electricity price is calculated according to 0.65 yuan / kWh, thermal power steam unit price is calculated according to 210 yuan / t, and annual operating time is calculated according to 8000h).

[0161] Example 1 (S1)

[0162] The energy-saving system as shown in Figure 1 and 2 The energy-saving method of the aniline-thermal power combination; wherein the aniline unit is a 200,000 tons / year aniline device;

[0163] The energy-saving method comprises:

[0164] The top aniline (220℃) of the fluidized bed reactor 101 in the aniline unit 1 is sequentially input into the first steam boiler 102 and the second steam boiler 103 for energy utilization to produce S10 steam and S4 steam, and the water from the first deaerator 108 is preheated by the heat recovery of the preheater 109 and then supplied to the first steam boiler 102 and the second steam boiler 103 for use, thereby increasing the production of S10 steam and S4 steam;

[0165] The aniline (132℃) from the second steam boiler 103 is input into the hot water heat exchanger 104 to produce 120℃ hot water for the thermal power unit 2 by using the residual heat;

[0166] The hot water from the hot water heat exchanger 104 is input into the desalted water heat exchanger 201 as a heat medium to preheat the desalted water from the desalted water tank 202, thereby saving the S10 steam used by the second deaerator 203, the hot water after heat exchange and cooling in the desalted water heat exchanger 201 is supplied to the user 204 to utilize the heat therein, then is input into the seawater cooler 205 to be further cooled to 60℃, and is output to the hot water tank 107 in the aniline unit 1 to reduce the influence of hot water flow fluctuation on the system, and then is sent into the hot water heat exchanger 104 to be heated by recycling aniline waste heat to form a hot water circulation.

[0167] The aniline (70℃) after heat exchange and cooling in the hot water heat exchanger 104 is input into the water cooler 105 to be cooled to below 40℃, and then is sent into the gas-liquid separation tank 106 to be gas-liquid separated to recycle hydrogen.

[0168] Comparative Example 1 (D1)

[0169] The energy saving is carried out by using the system as shown in Figure 3 The system is a 200,000 tons / year aniline device.

[0170] The energy saving method comprises the following steps.

[0171] The aniline (214℃) at the top of the fluidized bed reactor 101' is sequentially input into the first steam boiler (102') and the second steam boiler (103') to utilize energy to generate S10 steam and S4 steam.

[0172] The aniline (159℃) from the second steam boiler (103') is input into the air cooler 110' to be cooled.

[0173] The aniline (60℃) from the air cooler 110' is input into the water cooler 105' to be cooled to 40℃, and then is sent into the gas-liquid separation tank 106' to be gas-liquid separated to recycle hydrogen.

[0174] The related parameters of Example 1 and Comparative Example 1 are measured, and the measurement results are shown in Table 1.

[0175] Table 1 Measurement results of Example 1 and Comparative Example 1

[0176] Parameters Example 1 Comparative Example 1 Aniline heat utilization rate (%) 92 76 S10 steam production (t / h) 32 28 S4 steam production (t / h) 17 17 Hot water production (t / h) 100 0 Air cooling fan power (kW) 0 176 Thermal power saving steam (t / h) 15.5 0 Profit (ten thousand yuan / year) 9952 6584

[0177] According to Example 1 and Comparative Example 1 and Table 1, it can be known that:

[0178] The heat utilization rate of aniline in Example 1 of the present application is as high as 92%, and the heat utilization rate of aniline in Comparative Example 1 is only 76%;

[0179] The steam amount of by-product S10 of the embodiment 1 of the present application is 4t / h more than that of the comparative example 1.

[0180] Compared with the comparative example 1, the embodiment 1 of the present application reduces the air cooling power consumption by 176kW, and the steam saving of the thermal power unit is 15.5t / h;

[0181] The benefit of the embodiment 1 of the present application is 99,520,000 yuan per year, which is 3,368,000 yuan per year higher than that of the comparative example 1, and the energy saving effect and economic benefit are obvious.

Claims

1. A combined aniline-thermal power energy saving system, characterized in that, The energy-saving system comprises an aniline unit (1) and a thermoelectric unit (2); The aniline unit (1) comprises a fluidized bed reactor (101), a first steam boiler (102), a second steam boiler (103), a hot water heat exchanger (104), a water cooler (105), a gas-liquid separation tank (106), a hot water tank (107) and a first deaerator (108) connected by material pipelines; wherein, The fluidized bed reactor (101) is used for catalytic hydrogenation reaction of nitrobenzene, and aniline is output from the top gas phase outlet; The first steam boiler (102) is connected to the top gas phase outlet of the fluidized bed reactor (101), and is used for generating S10 steam by using the heat in the aniline from the fluidized bed reactor (101); The second steam boiler (103) is connected to the aniline outlet of the first steam boiler (102), and is used for generating S4 steam by using the waste heat in the aniline from the first steam boiler (102); The aniline inlet of the hot water heat exchanger (104) is connected to the aniline outlet of the second steam boiler (103), and the water inlet of the hot water heat exchanger (104) is connected to the water outlet of the hot water tank (107), which is used for heating the water in the hot water tank (107) by using the waste heat in the aniline from the second steam boiler (103) to supply the thermoelectric unit (2) as a heat medium; The first deaerator (108) is connected to the water inlets of the first steam boiler (102) and the second steam boiler (103) respectively, and is used for deaerating the input desalted water and then conveying the desalted water into the first steam boiler (102) and the second steam boiler (103) respectively as the water; One end of the water cooler (105) is connected to the aniline outlet of the hot water heat exchanger (104), and the other end is connected to the gas-liquid separation tank (106), which is used for further cooling the aniline from the hot water heat exchanger (104) and then sending the aniline to the gas-liquid separation tank (106) through the aniline outlet pipeline (111) for gas-liquid separation; The water inlet of the hot water tank (107) is connected to the water outlet pipeline of the thermoelectric unit (2), which is used for receiving the water from the thermoelectric unit (2); The thermoelectric unit (2) comprises a desalted water heat exchanger (201), a desalted water tank (202) and a second deaerator (203) connected by material pipelines; wherein, The water outlet of the desalted water tank (202) is connected to the desalted water channel inlet of the desalted water heat exchanger (201), which is used for storing desalted water to supply the desalted water heat exchanger (201); The desalted water channel inlet of the desalted water heat exchanger (201) is connected to the desalted water tank (202), and the heat medium channel inlet of the desalted water heat exchanger (201) is connected to the water outlet of the hot water heat exchanger (104), which is used for heating the desalted water from the desalted water tank (202) by using the water from the hot water heat exchanger (104); The second deaerator (203) is provided with a steam inlet and a desalted water inlet, and the steam inlet is connected to the steam feeding pipeline (206), and the desalted water inlet is connected to the desalted water passage outlet of the desalted water heat exchanger (201) for respectively feeding S10 steam and desalted water from the desalted water heat exchanger (201) and outputting the desalted water after deaeration through the second deaerator water outlet pipeline (214); The second deaerator (203) is provided with a desalted water inlet and a steam inlet; the desalted water inlet is connected to the desalted water passage outlet of the desalted water heat exchanger (201) for feeding desalted water from the desalted water heat exchanger (201); and the steam inlet is connected to the steam feeding pipeline (206) for feeding S10 steam to deaerate the desalted water.

2. The energy saving system of claim 1, wherein, The aniline unit (1) further comprises a preheater (109) arranged on the material pipeline from the second steam boiler (103) to the hot water heat exchanger (104), and the water inlet end of the preheater (109) is connected to the first deaerator (108), and the water outlet end is respectively connected to the water inlets of the first steam boiler (102) and the second steam boiler (103) for preheating the water from the first deaerator (108) by using the waste heat in the aniline from the second steam boiler (103) to supply the first steam boiler (102) and the second steam boiler (103).

3. The energy saving system according to claim 1 or 2, characterized in that, The heat and power unit (2) further comprises a user (204), and the water inlet of the user (204) is connected to the hot medium passage outlet of the desalted water heat exchanger (201) for outputting the water from the desalted water heat exchanger (201) as a hot medium and the heat therein.

4. The energy saving system of claim 3, wherein, The heat and power unit (2) further comprises a seawater cooler (205), and the water inlet of the seawater cooler (205) is connected to the water outlet of the user (204) for further cooling the water from the user (204) by using seawater as a cold medium and outputting the water through the water outlet pipeline (208).

5. The energy saving system of claim 4, wherein, The seawater inlet pipeline of the seawater cooler (205) is provided with a first valve (207); the heat and power unit (2) further comprises a first temperature indicating control device (209), and one end of the first temperature indicating control device (209) is connected to the water outlet pipeline (208) and the other end is connected to the first valve (207) for indicating the temperature of the material in the water outlet pipeline (208) and controlling the opening of the first valve (207) according to the temperature indication; and / or The steam feeding pipeline (206) is provided with a second valve (213); the heat and power unit (2) further comprises a second temperature indicating control device (216), and one end of the second temperature indicating control device (216) is connected to the second deaerator water outlet pipeline (214) and the other end is connected to the second valve (213) for indicating the temperature of the material in the second deaerator water outlet pipeline (214) and controlling the opening of the second valve (213) according to the temperature indication.

6. The energy saving system according to any one of claims 1, 2, 4 and 5, characterized in that, The aniline unit (1) further comprises an air cooler (110) having an inlet connected to the outlet pipeline of the thermoelectric unit (2) and an outlet connected to the water inlet of the hot water tank (107) for further cooling the water from the thermoelectric unit (2) and outputting to the hot water tank (107).

7. The energy saving system of claim 6, wherein, The air cooler (110) is provided with a fourth valve (112) on the inlet pipeline; the aniline unit (1) further comprises a third temperature indicating control device (116) having one end connected to the third pipeline (113) from the air cooler (110) to the hot water tank (107) and the other end connected to the fourth valve (112) for indicating the temperature of the material in the third pipeline (113) and controlling the opening of the fourth valve (112) according to the temperature indication; and / or The hot water heat exchanger (104) is provided with a fifth valve (118) on the water inlet pipeline (117), and a first flow indicating control device (119) is connected in parallel from the fifth valve (118) to the outlet of the fifth valve (118) for indicating the flow of the material in the water inlet pipeline (117) and controlling the opening of the fifth valve (118) according to the flow indication; and / or The water cooler (105) is provided with a sixth valve (120) on the cold medium feeding pipeline; the aniline unit (1) further comprises a fourth temperature indicating control device (121) having one end connected to the aniline outlet pipeline (111) and the other end connected to the sixth valve (120) for indicating the temperature of the material in the aniline outlet pipeline (111) and controlling the opening of the sixth valve (120) according to the temperature indication.

8. A method for energy saving by using the energy saving system according to any one of claims 1 to 7, characterized by, The energy-saving method comprises: The aniline output from the fluidized bed reactor (101) in the aniline unit (1) is sequentially subjected to energy utilization in the first steam boiler (102), the second steam boiler (103) and the hot water heat exchanger (104) to generate S10 steam, S4 steam and hot water for the thermoelectric unit (2) in sequence for further cooling and outputting; The hot water from the hot water heat exchanger (104) in the aniline unit (1) is input into the thermoelectric unit (2) to be used as a heat medium for the desalted water heat exchanger (201) to preheat the desalted water from the desalted water tank (202), the preheated desalted water is sent to the second deaerator (203) for deaeration, and the hot water from the aniline unit (1) is cooled by heat exchange and then output to the hot water tank (107) in the aniline unit (1) for circulation.

9. The energy-saving method according to claim 8, wherein The aniline unit (1) further comprises a preheater (109) provided on the material pipeline from the second steam boiler (103) to the hot water heat exchanger (104) and having an inlet connected to the first deaerator (108) and an outlet connected to the water inlets of the first steam boiler (102) and the second steam boiler (103); The energy-saving method further comprises: The aniline from the second steam boiler (103) is first used for energy by the preheater (109) to preheat the water from the first deaerator (108) and then supplied to the first steam boiler (102) and the second steam boiler (103), and the aniline cooled by heat exchange is used as the heat medium of the hot water heat exchanger (104) for energy.

10. The energy saving method according to claim 8 or 9, wherein, The thermoelectric unit (2) further comprises a user (204), and a water inlet of the user (204) is connected to an outlet of the heat medium channel of the desalted water heat exchanger (201); The energy saving method further comprises: water from the desalted water heat exchanger (201) as the heat medium is supplied to the user (204) for use.

11. The energy saving method according to claim 10, wherein, The thermoelectric unit (2) further comprises a seawater cooler (205), and a water inlet of the seawater cooler (205) is connected to a water outlet of the user (204); The energy saving method further comprises: water from the user (204) is sent to the seawater cooler (205) for further cooling and then output to the hot water tank (107) in the aniline unit (1) for circulation.

12. The energy saving method of claim 11, wherein, A first valve (207) is arranged on a seawater inlet pipeline of the seawater cooler (205), and the thermoelectric unit (2) further comprises a first temperature indicating control device (209), one end of which is connected to the water outlet pipeline (208) and the other end of which is connected to the first valve (207); The energy saving method further comprises: the temperature of the material in the water outlet pipeline (208) is indicated by the first temperature indicating control device (209), and the opening of the first valve (207) is controlled according to the temperature indication.

13. The energy saving method of claim 11, wherein, A second valve (213) is arranged on the steam feeding pipeline (206), and the thermoelectric unit (2) further comprises a second temperature indicating control device (216), one end of which is connected to the second deaerator water outlet pipeline (214) and the other end of which is connected to the second valve (213); The energy saving method further comprises: the temperature of the material in the second deaerator water outlet pipeline (214) is indicated by the second temperature indicating control device (216), and the opening of the second valve (213) is controlled according to the temperature indication.

14. The energy saving method according to any one of claims 8, 9 and 11-13, wherein, The aniline unit (1) further comprises an air cooler (110), a water inlet end of which is connected to a water outlet pipeline of the thermoelectric unit (2) and a water outlet end of which is connected to a water inlet of the hot water tank (107), for further cooling of the water outlet from the thermoelectric unit (2) and then output to the hot water tank (107); The energy saving method further comprises: water from the thermoelectric unit (2) is sent to the air cooler (110) for further cooling and then output to the hot water tank (107) for circulation.

15. The energy saving method of claim 14, wherein, The water inlet pipeline of the air cooler (110) is provided with a fourth valve (112); the aniline unit (1) further comprises a third temperature indication control device (116), one end of which is connected to a third pipeline (113) from the air cooler (110) to the hot water tank (107), and the other end is connected to the fourth valve (112); The energy-saving method further comprises: The third temperature indication control device (116) is used to indicate the material temperature in the third pipeline (113), and the opening of the fourth valve (112) is controlled according to the temperature indication.

16. The energy saving method of claim 15, wherein, The water inlet pipeline of the hot water heat exchanger (104) is provided with a fifth valve (118), and a first flow indication control device (119) is connected in parallel from the fifth valve (118) to the water outlet end of the fifth valve (118); The energy-saving method further comprises: The first flow indication control device (119) is used to indicate the material flow in the water inlet pipeline (117), and the opening of the fifth valve (118) is controlled according to the flow indication.

17. The energy saving method of claim 14, wherein, The cold medium inlet pipeline of the water cooler (105) is provided with a sixth valve (120); the aniline unit (1) further comprises a fourth temperature indication control device (121), one end of which is connected to the aniline outlet pipeline (111), and the other end is connected to the sixth valve (120); The energy-saving method further comprises: The fourth temperature indication control device (121) is used to indicate the material temperature in the aniline outlet pipeline (111), and the opening of the sixth valve (120) is controlled according to the temperature indication.

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