Waste heat recycling system

Abstract

The utility model relates to a waste heat recycling system which comprises a butylene device, a heat pump unit, a cooling tower and a petroleum refining device, the butylene device is connected with the heat pump unit through a first connecting pipeline, the heat pump unit is connected with the petroleum refining device through a second connecting pipeline and a third connecting pipeline, and the cooling tower is connected with the petroleum refining device through a second connecting pipeline. The heat pump unit is connected with the cooling tower through a second connecting pipeline and a fourth connecting pipeline, the petroleum refining device is used for catalytic cracking and / or continuous reforming, and circulating water pumps are arranged on the first connecting pipeline and the second connecting pipeline. On one hand, the temperature of the cooling water is reduced, the cooling water flows to catalytic cracking and / or continuous reforming through a pipeline, on the other hand, the heat pump unit generates high-temperature hot water, the high-temperature hot water flows to the butene device through a pipeline, hot water needed by the butene device for generating butene is met, cyclic utilization of the low-temperature cooling water is achieved, energy needed for heating the hot water is reduced, and energy consumption is reduced. The heating cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of catalytic cracking of wood, and in particular to a waste heat recovery and utilization system. Background Art

[0002] During the petroleum refining process, units like diesel cracking and continuous reforming currently rely on direct cooling with circulating water. Because this cooling water requires high-quality water, most currently use closed cooling towers for direct cooling. The material cooling process in these units consumes a lot of energy. When the cooling water temperature in these units exceeds 35°C, the cooling effect is poor, production capacity is reduced, and the waste heat from the cooling water is low, currently being directly discharged and not effectively recovered. Butene units require large quantities of hot water at temperatures between 75°C and 95°C during production. Currently, most use direct steam heating to provide this hot water, which results in high heating costs. Utility Model Content

[0003] The utility model aims at solving the existing technical problems and provides a waste heat recovery and utilization system.

[0004] The technical solution of the utility model for solving the above-mentioned technical problems is as follows: a waste heat recovery and utilization system, comprising a butene device, a heat pump unit, a cooling tower and an oil refining device, the butene device is connected to the heat pump unit through a first connecting pipe, the heat pump unit is connected to the oil refining device through a second connecting pipe and a third connecting pipe, the heat pump unit is connected to the cooling tower through a second connecting pipe and a fourth connecting pipe, the oil refining device is catalyzed diesel cracking and / or continuous reforming, and the first connecting pipe and the second connecting pipe are both provided with a circulating water pump.

[0005] On the basis of the above technical solution, the present invention can also be improved as follows:

[0006] Preferably, the heat pump units are provided in plurality, and the plurality of heat pump units are connected in parallel.

[0007] Preferably, the heat pump units are provided in plurality, the plurality of heat pump units are connected in series, and a circulating water pump is provided on the pipeline between adjacent heat pump units.

[0008] Preferably, the heat pump unit includes an absorption heat pump, an electrically driven heat pump unit or a water vapor compressor.

[0009] Preferably, the absorption heat pump includes a first type absorption heat pump, which uses a high temperature heat source as a driving heat source.

[0010] Preferably, the electrically driven heat pump unit includes a centrifugal heat pump unit, a screw heat pump unit or a scroll heat pump unit.

[0011] Preferably, the circulating medium in the first connecting pipe, the second connecting pipe, the third connecting pipe and the fourth connecting pipe is water, thermal oil, exhaust steam or steam.

[0012] The beneficial effects of the present invention are as follows: cooling water flows through the pipeline into the diesel cracking and / or continuous reforming device to cool it down, the cooling water is heated to a certain temperature, and returns to the heat pump unit through the pipeline, and the heated cooling water exchanges heat with the working medium in the heat pump unit. On the one hand, the cooling water temperature is reduced and flows again to the diesel cracking and / or continuous reforming through the pipeline; on the other hand, the heat pump unit generates high-temperature hot water, and the high-temperature hot water flows through the pipeline to the butene device to meet the hot water required by the butene device to produce butene, thereby realizing the recycling of low-temperature cooling water, reducing the energy required for heating hot water, and reducing heating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of Example 1 of the present utility model;

[0014] Figure 2 This is a schematic diagram of Example 2 of the present utility model.

[0015] The reference numerals are recorded as follows: 1. Butene unit; 2. Heat pump unit; 3. First connecting pipeline; 4. Cooling tower; 5. Second connecting pipeline; 6. Oil refining unit; 7. Third connecting pipeline; 8. Fourth connecting pipeline. DETAILED DESCRIPTION

[0016] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0017] Example 1

[0018] like Figure 1As shown, the utility model discloses a waste heat recovery and utilization system, including a butene device 1, a heat pump unit 2, a cooling tower 4, and an oil refining device 6. The butene device 1 is connected to the heat pump unit 2 via a first connecting pipe 3, and the heat pump unit 2 is connected to the oil refining device 6 via a second connecting pipe 5 and a third connecting pipe 7. The heat pump unit 2 is connected to the cooling tower 4 via a second connecting pipe 5 and a fourth connecting pipe 8. The oil refining device 6 is a diesel cracking and / or continuous reforming device. The first connecting pipe 3 and the second connecting pipe 5 are each equipped with a circulating water pump. The medium in the first connecting pipe 3, the second connecting pipe 5, the third connecting pipe 7, and the fourth connecting pipe 8 is water, thermal oil, exhaust steam, or steam. Because the temperature difference between the waste heat of the cooling water generated by the diesel cracking and / or continuous reforming and the stable heating required by the butene device 1 is large, the heat pump unit 2 is used for heat exchange and temperature increase. When the heat pump unit 2 is unable to recover all the waste heat of the cooling water, part of the cooling water enters the cooling tower 4 through the fourth connecting pipe 8 for cooling to meet the cooling water demand of diesel cracking and / or continuous reforming.

[0019] Specifically, the heat pump unit 2 includes an absorption heat pump, an electrically driven heat pump unit, or a water vapor compressor. The absorption heat pump includes a first-class absorption heat pump, which uses a small amount of high-temperature heat source, such as steam, high-temperature hot water, or combustible gas combustion heat, as a driving heat source. It uses a lithium bromide aqueous solution as a working fluid, with water as a refrigerant and lithium bromide as an absorbent, to generate a large amount of useful medium-temperature heat energy. In this embodiment, the ratio of the high-temperature heat source to the low-temperature heat source to the useful medium-temperature heat pump is approximately 1:0.6-1.3:1.6-2.3.

[0020] The electric-driven heat pump unit includes a centrifugal heat pump unit, a screw heat pump unit or a scroll heat pump unit, which uses electricity as a driving source and uses R134a, 245fa, etc. as a working fluid to absorb and compress the low-temperature and low-pressure working fluid into a high-temperature and high-pressure gas, and releases heat to the heat source, thereby achieving heating.

[0021] In this embodiment, when the waste heat recovery system is working, 30°C cooling water flows into the diesel cracking and / or continuous reforming device through the second connecting pipe 5 and the third connecting pipe 7 to cool it down, and the cooling water is heated to a certain temperature. In this embodiment, the cooling water is heated to 34°C, and the heated cooling water returns to the heat pump unit 2 through the pipe. The heated cooling water exchanges heat with the working medium in the heat pump unit 2. On the one hand, the cooling water temperature is reduced to 30°C and flows to the diesel cracking and / or continuous reforming device again through the pipe. On the other hand, the heat pump unit 2 generates high-temperature hot water of 95°C, which flows to the butene device 1 through the first connecting pipe 3 to meet the hot water required for the butene device 1 to produce butene. After heat exchange in the butene device 1, the hot water forms 75°C hot water and returns to the heat pump unit 2 through the first connecting pipe 3 for heat exchange again. The waste heat recovery system realizes the recycling of low-temperature cooling water, reduces the energy required for heating hot water, and reduces heating costs.

[0022] Example 2

[0023] like Figure 2 As shown, in this embodiment, two heat pump units 2 are provided, and the two heat pump units 2 are connected in series. A circulating water pump is provided on the pipeline between the two heat pump units 2. When a single heat pump unit 2 cannot raise the temperature to the required temperature in a single operation, a two-stage or multi-stage series connection is required. That is, one of the heat pump units 2 raises the temperature to an intermediate circulation temperature, such as 40°C-45°C, 50°C-60°C, or 60°C-65°C, by exchanging heat with the cooling water. After the two heat pump units 2 have exchanged heat, the other heat pump unit 2 raises the temperature to above 95°C, thereby meeting the heat requirements of the butene unit 1.

[0024] Optionally, when the temperature of the cooling water is below 20°C and the hot water temperature required by the butene device 1 reaches above 100°C, multiple heat pump units 2 can be connected in series to meet usage requirements under different conditions.

[0025] Optionally, when the heat exchange capacity of a single heat pump unit 2 cannot reach the required heat exchange capacity, two or more heat pump units 2 are connected in parallel to improve the overall heat exchange capacity of the heat pump unit 2.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A waste heat recovery system, characterized in that: The invention comprises a butene device (1), a heat pump unit (2), a cooling tower (4) and an oil refining device (6), wherein the butene device (1) is connected to the heat pump unit (2) via a first connecting pipe (3), the heat pump unit (2) is connected to the oil refining device (6) via a second connecting pipe (5) and a third connecting pipe (7), the heat pump unit (2) is connected to the cooling tower (4) via a second connecting pipe (5) and a fourth connecting pipe (8), the oil refining device (6) is a diesel cracking and / or continuous reforming device, and the first connecting pipe (3) and the second connecting pipe (5) are both provided with a circulating water pump.

2. The waste heat recovery system according to claim 1, characterized in that: The heat pump units (2) are provided with two or more, and the two or more heat pump units (2) are connected in parallel.

3. The waste heat recovery system according to claim 1, characterized in that: The heat pump units (2) are provided with two or more, and the two or more heat pump units (2) are connected in series, and a circulating water pump is provided on the pipeline between adjacent heat pump units (2).

4. The waste heat recovery system according to claim 1, 2 or 3, characterized in that: The heat pump unit (2) comprises an absorption heat pump, an electrically driven heat pump unit or a water vapor compressor.

5. The waste heat recovery system according to claim 4, characterized in that: The absorption heat pump includes a first type of absorption heat pump, which uses a high-temperature heat source as a driving heat source.

6. The waste heat recovery system according to claim 4, characterized in that: The electrically driven heat pump unit includes a centrifugal heat pump unit, a screw heat pump unit or a scroll heat pump unit.

7. The waste heat recovery system according to claim 1, characterized in that: The circulating medium in the first connecting pipe (3), the second connecting pipe (5), the third connecting pipe (7) and the fourth connecting pipe (8) is water, thermal oil, exhaust steam or steam.

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