CN203240840U - Energy saving system integrated by conversion section waste heat recovery and rectisol process refrigeration station - Google Patents

Abstract

The utility model relates to an energy saving system integrated by a conversion section waste heat recovery and rectisol process refrigeration station. The energy saving system comprises a first level propylene compressor (C1), a second level propylene compressor (C2), a propylene water cooler (E1), a propylene subcooler (NEW1), a heat exchanger (NEW2) and a separator (S1) which are sequentially connected. The bottom of the separator (S1) is connected with the first level propylene compressor (C1) through an evaporator system (E2), and the top of the separator (S1) is connected with the second level propylene compressor (C2). The propylene subcooler (NEW1) is communicated with a bromine cooling machine system (B1) to achieve heat exchange. A heat source of the bromine cooling machine system is from surplus low-pressure steam in the former working section, namely a conversion section, of a rectisol process. Heat exchange is conducted on the propylene subcooler and the bromine cooling machine system, heat is provided for the bromine cooling machine system, cooling capacity is obtained at the same time, and the refrigerating efficiency of refrigeration circulation is effectively improved.

Description

An energy-saving system integrating waste heat recovery in conversion section and low-temperature methanol washing process refrigeration station

technical field

The utility model relates to the technical field of refrigeration and waste heat utilization, in particular to an energy-saving system integrating waste heat recovery in a transformation section and a low-temperature methanol washing process freezing station.

Background technique

The low-temperature methanol washing process is a gas purification process. This process uses cold methanol as the absorption solvent, and utilizes the excellent characteristics of methanol's great solubility to acid gas at low temperature to remove the acid gas in the raw material gas. Due to the irreversibility of the absorption, desorption and heat transfer process, and the pump will generate a certain temperature rise during the transportation process, the low-temperature methanol washing process requires external cooling capacity.

Fig. 1 is the process flow diagram of existing low-temperature methanol washing. Its technological process is as follows:

The 5.4MPa, 40°C shift gas 1 from the shift merges with the cycle gas 2 sent by the flash gas compressor C3001. In order to prevent the shift gas from freezing below the freezing point, spray 1303kg/h lean methanol liquid 23 , and then exchange heat with purified gas 4, carbon dioxide 5, and tail gas 6 through raw material gas heat exchanger E3001 to cool to -20.15°C, and then separate methanol aqueous solution through water separator V3001, and dry raw gas enters methanol scrubber T3001.

The methanol washing tower T3001 is divided into upper and lower parts, the lower part is mainly used for desulfurization, and the upper part can be divided into three sections: the top section is the fine washing section, which is absorbed by lean methanol stream 24 at -54.99°C and 358906kg/h A small amount of CO ₂ and H ₂ S remaining in the gas, to ensure _that the CO ₂ ≤ 3% and H ₂ S ≤ 0.1ppm in the downstream purified gas 4; E3006 The washing liquid 31 of the fine cleaning section after heat exchange enters the CO ₂ absorption section at -35.75°C to absorb CO ₂ in the gas; the effluent 30 of the CO ₂ absorption section passes through the 3# methanol chiller E3005 and the circulating methanol cooler After E3006 is cooled, return to the CO ₂ absorption section to absorb CO ₂ in the gas; about 52% methanol rich liquid 25 is taken out from the tray at the bottom of the upper tower, and is exchanged with the purified gas 4 in the methanol cooler E3017, and then stimulated by 2# methanol The cooler E3004 cools down to -31.65°C, and enters the 2# circulating gas flash tank V3003 after reducing to 1850kPa, so that most of the H ₂ dissolved in the methanol liquid is evaporated.

When the lower tower is desulfurized, only part of the methanol liquid that has absorbed _CO2 in the upper tower is needed, and its amount is about 48% of the total amount. After being washed by the lower tower, the methanol liquid 26 containing all sulfur flows out from the bottom of the methanol washing tower T3001 tower, respectively After heat exchange and cooling in methanol heat exchanger E3007 and 1# methanol chiller E3003, after decompression to 1850kPa, it enters 1# circulating gas flash tank V3002 to flash most of the _H2 dissolved in methanol liquid. The H ₂ flashed from the 1# circulating gas flash tank V3002 and the 2# circulating gas flash tank V3003 passes through the circulating gas compressor C3001, and the pressure is raised to 5560kPa, cooled to -40°C by the compressor water cooler E3002, and sent back to the inlet The raw material gas pipeline is reused.

The methanol liquid 32 containing CO ₂ and no sulfur drawn from the bottom of the 2# circulating gas flash tank V3003 is throttled and expanded, and the pressure drops to 0.29MPa, and enters the top of the CO ₂ desorption tower T3002 to flash most of the CO ₂ A part of the gas is used as the reflux liquid 37 at the upper part of the CO ₂ desorption tower T3002, and a part is used as the reflux liquid 36 at the upper part of the H ₂ S concentration tower T3003.

The sulfur-containing and _CO2 methanol liquid 33 drawn from the bottom of the 1# circulating gas flash tank V3002, after throttling and expansion, the pressure drops to 0.35MPa, and enters the 8th tray in the middle of the _CO2 analysis tower T3002. Here, part CO ₂ and H ₂ S are decomposed from the methanol solution, and the methanol solution 38 is sent to the H ₂ S concentration tower T3003, part of the CO ₂ and H ₂ S are flashed off, and then the methanol-rich solution 34 is obtained by boosting pressure, which is then passed through 3# lean Methanol cooler E3008 and circulating methanol cooler E3006 enter the methanol flash tank V3007 for separation, the liquid part 35 passes through the pressurized demethanol heat exchanger E3007 for heat exchange, and then the flash vapor 13 and liquid part 35 enter the CO ₂ desorption tower T3002 at the same time Because the temperature of the methanol liquid entering the tower has risen from -63.13°C to -28.88°C, with the increase of temperature, the solubility of CO ₂ in methanol decreases, and a large amount of CO ₂ is desorbed under the CO ₂ desorption tower T3002. After the methanol liquid 39 from the bottom of the CO ₂ analysis tower T3002 enters the middle of the H ₂ S concentration tower T3003, CO ₂ is further extracted by the low-pressure nitrogen 15 gas, and this part of CO ₂ is separated from the top gas of the CO ₂ analysis tower T3002 along with the stripping nitrogen. The carbon dioxide 5 passes through the raw gas heat exchanger E3001 to recover cooling capacity. Claus hydrogenation tail gas 14 enters the bottom of the H ₂ S enrichment tower T3003. The temperature of the methanol liquid 41 at the bottom of the H ₂ S concentration tower T3003 is -43.46°C. After pressurization, it enters the 2# lean methanol cooler E3009 and the 1# lean methanol cooler E3010. The temperature rises to 87.4°C, and then enters the methanol thermal regeneration tower The 26th tray of T3004. All the H ₂ S and CO ₂ dissolved in the methanol liquid are stripped by the methanol steam generated by heating the reboiler E3011 of the regeneration tower, and at the same time stripped by the methanol steam 22 distilled from the top of the methanol water/separation tower T3005. The acid gas/methanol 16, which is part of the methanol vapor entrained by the heated acid gas, is drawn out from the top of the tower. After being cooled by the acid gas water cooler E3012, most of the methanol vapor is condensed, and the methanol condensate 42 is separated through the reflux tank V3006 as the reflux liquid , sent back to the top of the methanol thermal regeneration tower T3004 tower, leaving the sulfur-rich steam 17 at the top of the reflux liquid tank V3006, pre-cooled in the H ₂ S fraction heat exchanger E3014, and then in the acid gas quencher of the methanol thermal regeneration tower Further cooling in E3013. Here, almost all the methanol vapor is condensed and then separated by the acid gas separator V3005, the condensate 40 is sent to the bottom of the H ₂ S concentration tower T3003 for treatment, and part of the acid gas 18 is recycled to the H ₂ S concentration tower T3003 On the 25th tray, part of the cold energy is recovered by the H ₂ S fraction heat exchanger E3014 and then sent to the external sulfur recovery.

The regenerated methanol 43 is taken out from the bottom of the methanol thermal regeneration tower T3004, cooled in the 1# lean methanol cooler E3010, then sent to the methanol collection tank V3004, and then pressurized to 6.5MPa, cooled by the methanol water cooler E3018, and a small amount is removed as a spray Drenched with methanol, the rest is cooled to -54.99°C by 2# lean methanol cooler E3009 and 3# lean methanol cooler E3008, and then sent to the top of methanol washing tower T3001 as the washing liquid in the fine washing section.

Methanol/water 27 from the water separator V3001 exchanges heat with lean methanol 45 cooled from the bottom of the methanol thermal regeneration tower T3004 in the feed heater E3016 of the methanol/water separation tower. The feed separator V3008 of the water separation tower enters the 21st plate of the methanol/water separation tower T3005 tower. On the 13th tray plate of the separation tower T3005 tower, they participate in the distillation together. The steam at the bottom of the tower is generated by heat exchange with the reboiler E3015 of the methanol/water separation tower. After being distilled by 51 trays, the methanol vapor is directly sent to the methanol thermal regeneration tower T3004, and the methanol steam is cooled by the feed heater E3016 of the methanol water/separation tower. Lean methanol 45 is sent to the top of methanol water/separation tower T3005 as reflux. The waste water 49 at the bottom of the tower is discharged to the waste water treatment system after recovering heat in the water heat exchanger E3019, and its discharge rate is 2277kg/h.

At present, the refrigeration methods of the refrigeration station supporting the low-temperature methanol washing process mainly include propylene compression refrigeration, ammonia compression refrigeration, ammonia absorption refrigeration, ammonia compression absorption mixed refrigeration, etc. If it is used to produce synthetic ammonia, it is recommended to use ammonia as the refrigerant, otherwise it is recommended to use propylene as the refrigerant. The refrigeration temperature of propylene can reach -40°C, which cannot be achieved by ammonia under normal pressure. In addition, the inlet of the propylene compressor is positive pressure, and the design of the compressor is also more convenient.

The existing low-temperature methanol washing process is equipped with a high load capacity of the compressor of the propylene refrigeration station, a high load capacity of the propylene water cooler, and a large consumption of propylene.

The conversion section produces a lot of low-pressure steam due to overheating. This part of low-pressure steam can be converted into high-quality steam by adding waste heat boilers. Even so, in the actual factory, the low-pressure steam generated by the conversion section fluctuates greatly with the change of seasons. So it is difficult to utilize this part of the low-quality heat source.

The basic structure of the bromine refrigerator (lithium bromide refrigerator) is shown in Figure 4. The lithium bromide refrigerator uses steam as the heat source, lithium bromide solution as the absorbent, and water as the refrigerant. It has a secondary generation process and a primary absorption process. For its detailed working principle, please refer to "Structure and Principle of Lithium Bromide Absorption Refrigerator" published by Yang Weirong in "Guangdong Chemical Industry", Volume 36, Issue 5, 2009. In engineering, the thermal energy used by bromine chillers is generally low-quality thermal energy such as industrial waste heat, waste heat, and solar energy, and can use various energy forms such as natural gas and coal gas. It is an energy-saving equipment.

Utility model content

The purpose of this utility model is to provide a new energy-saving system integrating waste heat recovery in the conversion section and the freezing station of the low-temperature methanol washing process, that is, the heat absorption effect of propylene liquid gasification is used to realize refrigeration, and sufficient cooling capacity is provided for the low-temperature methanol washing process , At the same time, it can exchange heat with the bromine refrigerator system to provide heat and obtain cooling capacity.

The propylene liquid is vaporized in the evaporator system to provide cold energy. In order to keep the evaporation process going, it is necessary to continuously extract steam from the evaporator system, and then continuously replenish the liquid. To condense steam at room temperature, it is necessary to increase the steam pressure to the saturation pressure at room temperature, which realizes the evaporation of refrigerant at low temperature and low pressure, produces refrigeration effect and condenses at high temperature and high pressure, and releases heat to the outside. Liquid gasification refrigeration consists of four processes: gasification, pressure boost, condensation, and pressure reduction. The propylene compression refrigeration cycle continuously provides cooling capacity to the low-temperature methanol washing process.

For this purpose, the utility model adopts the following technical solutions:

An energy-saving system integrating waste heat recovery in a transformation section and a low-temperature methanol washing process refrigeration station, the system includes a first-stage propylene compressor, a second-stage propylene compressor, a propylene water cooler, a propylene subcooler, a heat exchanger and A separator, the bottom of the separator is connected to a primary propylene compressor through an evaporator system, and the top of the separator is connected to a secondary propylene compressor; the propylene subcooler is connected to a bromine cooler system to realize heat exchange.

The system described in the utility model includes a primary propylene compressor, a secondary propylene compressor, a propylene water cooler, a propylene subcooler, a heat exchanger, a separator, and an evaporator system; the primary propylene compressor is connected to a secondary propylene Compressor, the secondary propylene compressor is connected to the propylene water cooler, the propylene water cooler is connected to the propylene subcooler, the propylene subcooler is connected to the heat exchanger, the heat exchanger is connected to the separator, and the bottom of the separator passes through the evaporator system The first-stage propylene compressor is connected, and the top of the separator is connected to the second-stage propylene compressor; the propylene subcooler is connected with the bromine cooler system to realize heat exchange.

In the utility model, the bottom of the separator is connected to the primary propylene compressor through the evaporator system, and the top of the separator enters the secondary propylene compressor together with the primary propylene compressor.

The propylene vapor from the evaporator system enters the primary propylene compressor for pressurization, and enters the secondary propylene compressor together with the gas phase from the separator for pressurization. After compression, it enters the propylene water cooler, propylene subcooler, and then enters the heat exchanger After reducing the gas phase fraction, it enters the separator, and the separated liquid phase enters the evaporator system for evaporation and gasification. In the above process, the propylene subcooler exchanges heat with the bromine cooler system to provide heat for the bromine cooler system, and the propylene liquid in the propylene subcooler obtains corresponding cooling capacity.

The evaporator system described in the utility model is to provide cooling capacity for the low-temperature methanol washing process, which are: the ammonia cooler at the bottom of the absorption tower, the ammonia cooler in the middle of the absorption tower, the reflux liquid ammonia cooler in the middle of the absorption tower, and the heat regeneration tower Top chiller.

The heat exchanger described in the utility model is a heat exchanger connected in series with the chiller at the top of the thermal regeneration tower. In the original process, the load of the chiller at the top of the thermal regeneration tower is 423KW. It is 177KW, and the remaining 246kW cooling capacity is provided by the heat exchanger. The change of the evaporator system in the utility model is the change of the load of the chiller on the top of the thermal regeneration tower.

Compared with the prior art, the biggest difference of the utility model is that a propylene subcooler and a heat exchanger are added, and the propylene subcooler is connected with the bromine cooler system to realize heat exchange, and the bromine cooler utilizes the waste heat steam of the transformation section. The design of the propylene subcooler and heat exchanger can reduce the load of the propylene compressor and the cooling water of the propylene water cooler, and at the same time reduce the consumption of propylene, and more importantly, reduce the load of the compressor. In addition, the propylene subcooler provides heat for the bromine cooler system through heat exchange with the bromine cooler system, and at the same time obtains cooling capacity, which effectively improves the refrigeration efficiency of the refrigeration cycle. The heat source of the bromine cooler uses the excess low-pressure steam from the transformation section before the low-temperature methanol washing process, which realizes the reuse of low-quality heat sources.

The shell side inlet of the propylene subcooler described in the utility model is connected with the shell side outlet of the propylene water cooler, and the shell side outlet of the propylene subcooler is connected with the shell side inlet of the heat exchanger; The water of the bromine chiller system is passed into the tube side, and the propylene liquid is used in the shell side. The tube-side inlet of the propylene subcooler communicates with the throttle valve of the bromine cooler system, and the outlet communicates with the absorber of the bromine cooler system.

The outlet of the shell side of the heat exchanger in the utility model is connected with the separator; the tube side of the heat exchanger is fed with the sulfur-rich steam separated from the reflux liquid tank in the low-temperature methanol washing process. In the heat exchanger, the propylene liquid exchanges heat with the sulfur-rich vapor separated from the reflux liquid tank at the top of the methanol thermal regeneration tower in the low-temperature methanol washing process.

The shell-side inlet of the evaporator system of the utility model communicates with the bottom of the separator, and the shell-side outlet of the evaporator system communicates with the inlet of the first-stage propylene compressor. The shell side of the evaporator system is fed into the effluent of the _CO2 absorption section of the methanol washing tower in the low-temperature methanol washing process. In the evaporator system, the liquid phase (propylene liquid) from the bottom of the separator exchanges heat with the effluent (methanol solution) of the _CO2 absorption section of the methanol scrubber, during the heat exchange process, the propylene liquid is vaporized, due to the gas The endothermic effect of CO 2 absorption provides cooling capacity for the effluent (methanol solution) of the CO ₂ absorption section to achieve refrigeration.

A first throttling valve is provided between the propylene subcooler and the heat exchanger described in the utility model. A second throttle valve is provided between the bottom of the separator and the evaporator system in the utility model. Both the first throttle valve and the second throttle valve are used to further reduce the pressure of the propylene stream.

The bromine cooler system includes an absorber, an evaporator, a throttle valve, and a condenser connected in sequence, wherein the propylene subcooler is used to replace the evaporator, so that the tubes of the propylene subcooler (NEW1) Process as a part of the bromine chiller system (B1) circulation pipeline.

The tube-side inlet of the propylene subcooler communicates with the throttle valve outlet of the bromine cooler system, and the tube-side outlet of the propylene subcooler communicates with the absorber inlet of the bromine cooler system.

The first-stage propylene compressor and the second-stage propylene compressor described in the utility model use 2.5Mpa (G), 380°C superheated steam to drive the steam turbine.

Compared with the prior art solutions, the utility model has the following beneficial effects:

The utility model utilizes the waste heat steam of the transformation section as the heat source of the bromine refrigerator, provides cooling capacity above zero for the refrigeration device of the low-temperature methanol washing process, and improves the refrigeration efficiency of the refrigeration cycle.

The utility model adds a propylene subcooler and a heat exchanger, and connects the propylene subcooler with a bromine cooler system to realize heat exchange. The design of the propylene subcooler and heat exchanger can reduce the cooling water load of the propylene compressor and the propylene water cooler, and at the same time reduce the consumption of propylene. In addition, the propylene subcooler provides heat for the bromine cooler system through heat exchange with the bromine cooler system, and at the same time obtains cooling capacity, which realizes the full use of heat and the refrigeration of propylene liquid, thus providing enough for the low-temperature methanol washing process Cooling capacity. Heat exchangers are installed to provide different cooling levels, making the refrigeration cycle more energy efficient.

Since the compressor uses superheated steam of 2.5Mpa (G) and 380°C to drive the steam turbine, reducing the load of the compressor can significantly reduce the operating cost of the enterprise.

Relying on the 600,000 tons/year coal gasification to methanol project, there is at least 5t/h, 0.3Mpa(g), and 143°C steam waste in actual plant operation. In the utility model, this part of steam is used as the heat source of the bromine cooler, which reduces waste on the one hand, and on the other hand, the bromine cooler can provide 7°C chilled water for the freezing device. The utility model can reduce the compressor load by 16.96% by adding propylene supercooler, bromine cooler equipment and heat exchanger. The cooling water consumption of the propylene refrigeration compression cycle decreased by 1930KW, but the cooling water consumption of the bromine chiller equipment increased by 983KW, the final cooling water consumption decreased by 947KW, and the propylene consumption decreased by 4.8%.

Description of drawings

Fig. 1 is the process flow diagram of original low-temperature methanol washing;

Fig. 2 is a flow chart of the original propylene compression refrigeration process;

Fig. 3 is a flow chart of the utility model propylene compression refrigeration process;

Fig. 4 is a structural schematic diagram of an existing bromine refrigerator (lithium bromide refrigerator).

In Figure 2-4: C1-one-stage propylene compressor; C2-two-stage propylene compressor; E1-propylene water cooler; E2-evaporator system; NEW1-propylene subcooler; NEW2-heat exchanger; S1-separation V1-first throttle valve; V2-second throttle valve; B1-bromine chiller system; 1-condenser; 2-generator; 3-solution pump; 4-solution throttle valve; 5-absorption device; 6-evaporator; 7-throttle valve.

Below the utility model is described in further detail. But the following examples are only simple examples of the utility model, and do not represent or limit the protection scope of the utility model, and the protection scope of the utility model shall be determined by the claims.

Detailed ways

In order to better illustrate the utility model and facilitate understanding of the technical solution of the utility model, the typical but non-limiting examples of the utility model are as follows:

An energy-saving system integrating waste heat recovery in conversion section and refrigeration station of low-temperature methanol washing process, the system includes sequentially connected primary propylene compressor C1, secondary propylene compressor C2, propylene water cooler E1, propylene subcooler NEW1, Heat exchanger NEW2, separator S1, the bottom of the separator S1 is connected to the primary propylene compressor C1 through the evaporator system E2, and the top of the separator S1 is connected to the secondary propylene compressor C2; the propylene subcooler NEW1 It is connected with bromine refrigerator system B1 to realize heat exchange.

The shell-side inlet of the propylene subcooler NEW1 communicates with the shell-side outlet of the propylene water cooler E1, and the shell-side outlet of the propylene subcooler NEW1 communicates with the shell-side inlet of the heat exchanger NEW2; the propylene subcooler The lithium bromide aqueous solution of the bromine cooler system B1 is passed into the tube side of NEW1.

The shell-side outlet of the heat exchanger NEW2 communicates with the separator S1; the tube side of the heat exchanger NEW2 is fed with the sulfur-rich steam separated from the reflux liquid tank in the low-temperature methanol washing process.

The shell-side inlet of the evaporator system E2 communicates with the bottom of the separator S1, and the shell-side outlet of the evaporator system E2 communicates with the inlet of the primary propylene compressor C1.

A first throttling valve V1 is provided between the propylene subcooler NEW1 and the heat exchanger NEW2. A second throttle valve V2 is provided between the bottom of the separator S1 and the evaporator system E2.

The bromine cooler system B1 includes an absorber, an evaporator, a throttle valve, and a condenser connected in sequence, wherein the propylene subcooler NEW1 is used to replace the evaporator, so that the propylene subcooler (NEW1) The tube side is used as a part of the circulation pipeline of the bromine chiller system (B1).

The tube-side inlet of the propylene subcooler NEW1 communicates with the throttle valve outlet of the bromine cooler system B1, and the tube-side outlet of the propylene subcooler NEW1 communicates with the absorber inlet of the bromine cooler system B1.

The first-stage propylene compressor C1 and the second-stage propylene compressor C2 use superheated steam at 2.5Mpa (G) and 380°C to drive the steam turbine.

As shown in Figure 2, the original propylene compression refrigeration process is as follows:

The gaseous propylene stream (-40°C, 1.41bar, 49850kg/h) from the evaporator system E2 enters the boundary area of the refrigeration station, is pressurized to 4.86bar, 26.55°C by the primary propylene compressor C1, and then gas-phased with the separator S1 (-5.68°C, 4.86bar, 22320kg/h) is mixed and enters the secondary propylene compressor C2, compressed to 16.49bar, 88.02°C, and enters the propylene water cooler E1. The temperature of the stream exiting the propylene water cooler E1 is 40°C, and then enters the first throttling valve V1, and the pressure drops to 4.86 bar. The liquid phase stream from the separator V1, with a temperature of -5.68°C, is sent to the evaporator system E2 for evaporation and gasification after being depressurized by the second throttle valve V2.

As shown in Figure 3, the utility model propylene compression refrigeration process flow is as follows:

The gaseous propylene stream (-40°C, 1.41bar, 47360kg/h) from the evaporator system E2 enters the boundary area of the refrigeration station, is pressurized to 4.86bar, 26.55°C by the primary propylene compressor C1, and then gas-phased with the separator S1 (-5.68°C, 4.86bar, 17000kg/h) is mixed and enters the secondary propylene compressor C2, compressed to 16.49bar, 89.48°C, and enters the propylene water cooler E1. The temperature of the stream exiting the propylene water cooler E1 is 40°C, and then enters the propylene subcooler NEW1.

Propylene subcooler NEW1 is supplied by bromine cooler system B1 to exchange heat with propylene liquid. The temperature of the stream exiting the propylene subcooler NEW1 is 18°C, and then enters the first throttle valve V1, the pressure is reduced to 4.86 bar, and then passes through the heat exchanger NEW2, and the gas fraction of the stream is reduced from 0.1504 to 0.1078. The liquid phase stream from the separator S1, with a temperature of -5.68°C, is sent to the evaporator system E2 for evaporation after being depressurized by the second throttle valve V2.

The original propylene compression refrigeration process of table 1 is compared with the utility model process

Taking the 600,000 tons/year coal gasification to methanol project as an example, through the preferred implementation of the technical solution of the utility model, that is, by adding propylene subcooler and bromine cooler equipment and heat exchangers, the compressor load can be reduced by 16.96% . The cooling water consumption of the propylene refrigeration compression cycle decreased by 1930KW. Although the cooling water consumption of the bromine chiller equipment increased by 983KW, the final cooling water consumption decreased by 947KW, and the propylene consumption decreased by 4.8%.

The applicant declares that the utility model illustrates the detailed connection mode and structural features of the technical equipment of the utility model through the above-mentioned embodiments, but the utility model is not limited to the above-mentioned connection mode and structural features, that is, it does not mean that the utility model must rely on The above-mentioned detailed structural features and process methods can be implemented. Those skilled in the art should understand that any improvement of the utility model, the equivalent replacement of the selected components of the utility model, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the utility model within.

Claims (8)

1. the integrated energy conserving system of a conversion section Waste Heat Recovery and low-temp methanol washing process refrigeration station, it is characterized in that, described system comprises one-level propylene compressor (C1), secondary propylene compressor (C2), propylene water cooler (E1), propylene subcooler (NEW1), heat exchanger (NEW2) and the separator (S1) that connects successively, the bottom of described separator (S1) connects one-level propylene compressor (C1) by evaporator system (E2), and described separator (S1) top connects secondary propylene compressor (C2); Described propylene subcooler (NEW1) is communicated with bromine cooling machine system (B1) realizes heat exchange.

2. the system as claimed in claim 1, it is characterized in that, the shell side entrance of described propylene subcooler (NEW1) is communicated with the shell side outlet of propylene water cooler (E1), and the shell side outlet of described propylene subcooler (NEW1) is communicated with the shell side entrance of heat exchanger (NEW2).

3. system as claimed in claim 1 or 2 is characterized in that, the shell side outlet of described heat exchanger (NEW2) is communicated with separator (S1).

4. system as claimed in claim 1 or 2 is characterized in that, the shell side entrance of described evaporator system (E2) is communicated with the bottom of separator (S1), and the shell side outlet of described evaporator system (E2) is communicated with one-level propylene compressor (C1) entrance.

5. the system as claimed in claim 1 is characterized in that, is provided with first throttle valve (V1) between described propylene subcooler (NEW1) and the heat exchanger (NEW2).

6. the system as claimed in claim 1 is characterized in that, is provided with the second choke valve (V2) between the bottom of described separator (S1) and the evaporator system (E2).

7. the system as claimed in claim 1, it is characterized in that, described bromine cooling machine system (B1) comprises absorber, evaporimeter, choke valve, the condenser that connects successively, wherein, replace described evaporimeter with described propylene subcooler (NEW1), make the tube side of described propylene subcooler (NEW1) as the part in bromine cooling machine system (B1) circulation line.

8. system as claimed in claim 7, it is characterized in that, the tube side entrance of described propylene subcooler (NEW1) is communicated with the choke valve outlet of bromine cooling machine system (B1), and the tube side outlet of described propylene subcooler (NEW1) is communicated with the absorber entrance of bromine cooling machine system (B1).

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