Steam condensate waste heat recycling system for heat transfer oil heat exchange station

Abstract

The utility model discloses a steam condensate waste heat recycling system of a conduction oil heat exchange station, which is characterized in that an outlet of a low-temperature conduction oil return pipe is respectively connected with a tube pass inlet of each heating medium heat exchanger, and a tube pass outlet of each heating medium heat exchanger is respectively connected with an inlet of a high-temperature conduction oil heat supply pipe; a shell pass top inlet of each heating medium heat exchanger is connected with an inlet of the high-temperature and high-pressure steam pipe, and a shell pass bottom outlet of each heating medium heat exchanger is connected with an inlet of the flash tank. A top outlet of the flash tank is connected with a flash steam output pipe I and a flash steam output pipe II, and a bottom outlet of the flash tank is connected with a flash tank condensate pipe; an outlet of the flash steam output pipe I is connected with a waste heat steam using unit; the second flash steam output pipe and an outlet of the low-temperature condensate pipe are both connected with a heating medium inlet of the low-temperature waste heat generator set, and a condensate water outlet of the low-temperature waste heat generator set is connected with the low-temperature condensate pipe. The system makes full use of the heat value of condensate water and is matched with low-cost materials, the device cost is reduced, and the requirements of other steam using units of the device are met.

Description

Technical Field

[0001] The utility model relates to a heat transfer oil heat exchange station, in particular to a steam condensate waste heat recycling system of the heat transfer oil heat exchange station, belonging to the technical field of waste heat utilization devices. Background Art

[0002] Polybutylene terephthalate adipate (PBAT) is a biodegradable material. Its waste products can be quickly degraded in soil or water. The degradation products are non-toxic and widely used. It can be used to make disposable shopping bags, agricultural films, biomedical polymer materials, packaging bottles, etc. It can effectively solve white pollution and is increasingly used.

[0003] PBAT production requires a lot of heat, which is generally provided by heat transfer oil as a medium. The heat of the heat transfer oil comes from natural gas combustion or steam heat exchange. The high-pressure steam in thermal power plants is more likely to use steam heat exchange heat transfer oil because of its low price, low one-time investment, high production capacity or multiple production lines.

[0004] The Chinese utility model patent with the announcement number CN 221237991U discloses a device for heating heat transfer oil by steam, including a heat transfer oil system, wherein the first outlet of the heat transfer oil system is connected to the inlet of the circulating pump of the oil unloading tank of the heat exchange station, the outlet of the circulating pump of the oil unloading tank of the heat exchange station is connected to the inlet of the oil unloading tank of the heat exchange station, the second outlet of the heat transfer oil system is connected to the inlet of the oil unloading tank of the heat exchange station, the outlet of the oil unloading tank of the heat exchange station is connected to the inlet of the circulating pump of the heat transfer oil steam heater, the outlet of the circulating pump of the heat transfer oil steam heater is connected to the inlet of the heat transfer oil steam heater, the outlet of the heat transfer oil steam heater is connected to the inlet of the heat use device, and the outlet of the heat use device is connected to the inlet of the circulating pump of the heat transfer oil steam heater. This technical solution uses steam to heat the heat transfer oil for the process system of polystyrene production, eliminates the use of natural gas heating furnace, and achieves the purpose of reducing heating costs; however, there are still the following shortcomings:

[0005] 1. The calorific value of high-pressure steam is not effectively utilized after heat exchange;

[0006] 2. The transportation of high-temperature and high-pressure condensate exceeds the use range of 20 carbon steel in GB / T8163, and alloy steel must be used, which increases the cost of pipelines and fittings;

[0007] 3. Other steam-using units in PBAT production also require municipal steam supply. Utility Model Content

[0008] The purpose of the utility model is to overcome the problems existing in the prior art and provide a waste heat recycling system for steam condensate in a heat transfer oil heat exchange station, which makes full use of the calorific value of the condensate after the heat transfer oil is exchanged, adapts to low-cost materials, reduces the cost of the device, and meets the needs of other steam-consuming units of the device without the need to purchase additional steam.

[0009] In order to solve the above technical problems, the utility model discloses a heat transfer oil heat exchange station steam condensate waste heat recycling system, comprising a high-temperature heat transfer oil heat supply pipe and a low-temperature heat transfer oil return pipe, wherein the outlet of the low-temperature heat transfer oil return pipe is respectively connected to the pipe side inlet of each heat medium heat exchanger, and the pipe side outlet of each heat medium heat exchanger is respectively connected to the inlet of the high-temperature heat transfer oil heat supply pipe; the shell side top inlet of each heat medium heat exchanger is respectively connected to the inlet of the high-temperature and high-pressure steam pipe, and the shell side bottom outlet of each heat medium heat exchanger is respectively connected to the inlet of the flash tank through a condensate regulating valve and a high-temperature condensate pipe;

[0010] The top outlet of the flash tank is connected to flash steam output pipe 1 and flash steam output pipe 2, and the bottom outlet of the flash tank is connected to a flash tank condensate pipe; the outlet of the flash steam output pipe 1 is connected to a waste heat steam unit; the inlet of the flash steam output pipe 2 is equipped with a flash steam regulating valve, the outlets of the flash steam output pipe 2 and the low-temperature condensate pipe are both connected to the heat medium inlet of a low-temperature waste heat generator set, and the condensate outlet of the low-temperature waste heat generator set is connected to the low-temperature condensate pipe.

[0011] Furthermore, the waste heat steam utilization unit includes a tetrahydrofuran recovery distillation tower, a stripping tower, a filter element cleaning system, a catalyst configuration system, a BDO storage tank or a heating pipeline.

[0012] Furthermore, in the low-temperature waste heat power generation unit, the outlet of the flash steam output pipe 2 is connected to the tube side inlet of the evaporator, the tube side outlet of the evaporator is connected to the tube side inlet of the preheater, the tube side outlet of the preheater is connected to the hot side inlet of the aftercooler, and the hot side outlet of the aftercooler is connected to the low-temperature condensed water pipe;

[0013] The shell side outlet of the condenser is connected to the inlet of the working fluid pump, the outlet of the working fluid pump is connected to the shell side inlet of the preheater, the shell side outlet of the preheater is connected to the shell side inlet of the evaporator, the shell side outlet of the evaporator is connected to the medium inlet of the turbine generator, and the medium outlet of the turbine generator is connected to the shell side inlet of the condenser.

[0014] Furthermore, the opening of the condensate regulating valve is controlled by the liquid level of the corresponding heat medium exchanger.

[0015] Furthermore, the opening of the flash steam regulating valve on the flash steam output pipe 2 is controlled by the pressure of the flash steam output pipe 1.

[0016] Compared with the prior art, the utility model has achieved the following beneficial effects: 1. The steam is sent to the flash tank for flash evaporation to obtain 1.0MPa saturated steam, a part of which is supplied to other steam-using units of the device, such as tetrahydrofuran recovery distillation tower, stripping tower, filter element cleaning system, catalyst configuration system, BDO storage tank, and heating pipeline, and the excess part is used for ORC power generation and for use in this device;

[0017] 2. The condensed water at the bottom of the flash tank is sent to ORC to generate electricity for use in this device;

[0018] 3. After power generation and voltage reduction, the condensed water temperature drops to about 60°C and is then sent to the living area for showering, cooking, etc.;

[0019] 4. The commissioning of this system will realize the full utilization of the calorific value of the PBAT full-continuous production heat transfer oil heat exchange station, reduce production costs, reduce resource waste, and promote the development of environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. The accompanying drawings are only provided for reference and explanation and are not intended to limit the present invention.

[0021] Figure 1 This is a flow chart of the steam condensate waste heat recycling system of the thermal oil heat exchange station of the utility model;

[0022] In the figure: 1. Heat medium heat exchanger; 2. Flash tank; 3. Waste heat steam unit; 4. Low temperature waste heat generator set: 4a. Evaporator; 4b. Turbine generator; 4c. Condenser; 4d. Working fluid pump; 4e. Preheater; 4f. Aftercooler;

[0023] G1. High-temperature heat transfer oil supply pipe; G2. Low-temperature heat transfer oil return pipe; G3. High-temperature and high-pressure steam pipe; G4. High-temperature condensate water pipe; G5. Flash steam output pipe 1; G6. Flash steam output pipe 2; G7. Flash tank condensate water pipe; G8. Low-temperature condensate water pipe; V1. Condensate water regulating valve; V2. Flash steam regulating valve. DETAILED DESCRIPTION

[0024] In the following description of the utility model, the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not mean that the device must have a specific direction.

[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below with reference to specific illustrations.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0027] like Figure 1 As shown, the steam condensate waste heat recycling system of the heat transfer oil heat exchange station of the utility model comprises a heat medium heat exchanger 1, a flash tank 2, a waste heat steam unit 3 and a low-temperature waste heat power generation unit 4, the outlet of the low-temperature heat transfer oil return pipe G2 is respectively connected to the tube side inlet of each heat medium heat exchanger 1, and a plurality of heat medium heat exchangers 1 are usually arranged in parallel; the tube side outlet of each heat medium heat exchanger 1 is respectively connected to the inlet of the high-temperature heat transfer oil heat supply pipe G1; the shell side top inlet of each heat medium heat exchanger 1 is respectively connected to the inlet of the high-temperature and high-pressure steam pipe G3, and the shell side bottom outlet of each heat medium heat exchanger 1 is respectively connected to the inlet of the flash tank 2 through the condensate regulating valve V1 and the high-temperature condensate pipe G4, and the opening of each condensate regulating valve V1 is controlled by the liquid level of the corresponding heat medium heat exchanger 1.

[0028] The top outlet of the flash tank 2 is connected to the flash steam output pipe 1 G5 and the flash steam output pipe 2 G6, and the bottom outlet of the flash tank 2 is connected to the flash tank condensate pipe G7. The outlet of the flash steam output pipe 1 G5 is connected to the waste heat steam unit 3; the waste heat steam unit 3 includes a tetrahydrofuran recovery distillation tower, a stripping tower, a filter element cleaning system, a catalyst configuration system, a BDO storage tank or a heating pipeline.

[0029] A flash steam regulating valve V2 is installed at the inlet of the flash steam output pipe G6, and the opening of the flash steam regulating valve V2 is controlled by the pressure of the flash steam output pipe G5; the outlets of the flash steam output pipe G6 and the low-temperature condensate water pipe G8 are both connected to the heat medium inlet of the low-temperature waste heat generator set 4, and the condensate water outlet of the low-temperature waste heat generator set 4 is connected to the low-temperature condensate water pipe G8.

[0030] In the low-temperature waste heat generator set 4, the outlet of the flash steam output pipe G6 is connected to the tube side inlet of the evaporator, the tube side outlet of the evaporator is connected to the tube side inlet of the preheater, the tube side outlet of the preheater is connected to the hot side inlet of the aftercooler, and the hot side outlet of the aftercooler is connected to the low-temperature condensed water pipe G8;

[0031] The shell side outlet of the condenser is connected to the inlet of the working fluid pump, the outlet of the working fluid pump is connected to the shell side inlet of the preheater, the shell side outlet of the preheater is connected to the shell side inlet of the evaporator, the shell side outlet of the evaporator is connected to the medium inlet of the turbine generator, and the medium outlet of the turbine generator is connected to the shell side inlet of the condenser.

[0032] Thermal oil is often used as a heat carrier for high-temperature heating because of its high temperature resistance, stable quality, no deterioration, and no phase change. Traditional PBAT production equipment uses a natural gas thermal oil furnace. The natural gas burns to heat the thermal oil, and then the thermal oil heats the material for reaction. The high cost of natural gas leads to a high cost per ton of product. The actual required heat carrier temperature is lower than 320°C. The use of high-pressure superheated steam produced as a by-product of thermal power plants can significantly reduce production costs.

[0033] 13MPa, 375℃ high-pressure superheated steam is sent to the boundary area, and heats the heat transfer oil through each heat medium heat exchanger 1, heating the heat transfer oil from 270℃ to 295~300℃. The steam after heat exchange is condensed, and the pressure becomes 12.9MPa, and the temperature becomes 280℃ condensed water and enters the flash tank 2. The heat exchanger liquid level cascade controls the condensed water volume, thereby controlling the steam consumption and the heat transfer oil temperature.

[0034] The condensed water is flashed in the flash tank 2 to obtain saturated steam at 1 MPa and 184°C. A part of the saturated steam is supplied to the waste heat steam unit 3 of the PBAT production device, including a tetrahydrofuran recovery distillation tower, a stripping tower, a catalyst configuration system, a filter element cleaning system, etc.; the excess saturated steam is sent to the low-temperature waste heat generator set 4 for power generation.

[0035] The low-temperature condensed water in the flash tank 2 still has considerable calorific value and is also sent to generate electricity. The steam and condensed water enter the hot side of the evaporator 4a to heat the liquid circulating medium, generate high-temperature and high-pressure circulating medium steam, drive the turbine of the turbine generator 4b to work, generate electrical energy output, and the high-temperature and high-pressure steam is simultaneously reduced in pressure to become low-pressure steam and enter the hot side of the condenser 4c, release heat to the low-temperature heat source and condense into liquid, and then is pressurized by the medium pump 4d and sent to the preheater 4e to exchange heat with the incoming high-temperature steam and condensed water to become steam, completing a cycle.

[0036] The electricity generated by the low-temperature waste heat generator set 4 is sent to the grid for use by the PBAT production device, thereby saving electricity costs. The steam and condensed water after generating electricity are uniformly cooled by the aftercooler 4f to become 60°C condensed water, which is sent to the living area for waste heat utilization, such as bathing, etc.

[0037] The above description is only the preferred feasible embodiment of the utility model, which shows and describes the basic principle, main features and advantages of the utility model, but does not limit the scope of patent protection of the utility model. The technicians in this industry should understand that the utility model is not limited by the above embodiments. In addition to the above embodiments, the utility model can also have other implementation modes without departing from the spirit and scope of the utility model. The utility model will also have various changes and improvements. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the utility model. The scope of protection required by the utility model is defined by the attached claims and their equivalents. The technical features not described in the utility model can be achieved by or using existing technologies, which will not be repeated here.

Claims

1. A system for recycling waste heat of steam condensed water in a thermal oil heat exchange station, comprising a high-temperature thermal oil supply pipe and a low-temperature thermal oil return pipe, characterized in that: The outlet of the low-temperature heat transfer oil return pipe is respectively connected to the tube side inlet of each heat medium heat exchanger, and the tube side outlet of each heat medium heat exchanger is respectively connected to the inlet of the high-temperature heat transfer oil heat supply pipe; the shell side top inlet of each heat medium heat exchanger is respectively connected to the inlet of the high-temperature and high-pressure steam pipe, and the shell side bottom outlet of each heat medium heat exchanger is respectively connected to the inlet of the flash tank through the condensate regulating valve and the high-temperature condensate pipe; The top outlet of the flash tank is connected to flash steam output pipe 1 and flash steam output pipe 2, and the bottom outlet of the flash tank is connected to a flash tank condensate pipe; the outlet of the flash steam output pipe 1 is connected to a waste heat steam unit; the inlet of the flash steam output pipe 2 is equipped with a flash steam regulating valve, the outlets of the flash steam output pipe 2 and the low-temperature condensate pipe are both connected to the heat medium inlet of a low-temperature waste heat generator set, and the condensate outlet of the low-temperature waste heat generator set is connected to the low-temperature condensate pipe.

2. The system for recycling waste heat of steam condensed water from a thermal oil heat exchange station according to claim 1 is characterized in that: The waste heat steam utilization unit includes a tetrahydrofuran recovery distillation tower, a stripping tower, a filter element cleaning system, a catalyst configuration system, a BDO storage tank or a heating pipeline.

3. The system for recycling waste heat of steam condensed water from a thermal oil heat exchange station according to claim 1 is characterized in that: In the low-temperature waste heat power generation unit, the outlet of the flash steam output pipe 2 is connected to the tube side inlet of the evaporator, the tube side outlet of the evaporator is connected to the tube side inlet of the preheater, the tube side outlet of the preheater is connected to the hot side inlet of the aftercooler, and the hot side outlet of the aftercooler is connected to the low-temperature condensed water pipe; The shell side outlet of the condenser is connected to the inlet of the working fluid pump, the outlet of the working fluid pump is connected to the shell side inlet of the preheater, the shell side outlet of the preheater is connected to the shell side inlet of the evaporator, the shell side outlet of the evaporator is connected to the medium inlet of the turbine generator, and the medium outlet of the turbine generator is connected to the shell side inlet of the condenser.

4. The system for recycling waste heat of steam condensed water from a thermal oil heat exchange station according to claim 1, characterized in that: The opening degree of the condensate regulating valve is controlled by the liquid level of the corresponding heat medium heat exchanger.

5. The system for recycling waste heat of steam condensate from a thermal oil heat exchange station according to any one of claims 1 to 4, characterized in that: The opening degree of the flash steam regulating valve on the flash steam output pipe 2 is controlled by the pressure of the flash steam output pipe 1.

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