Heat pump system for supplying heat and cold for rectification

Abstract

The utility model discloses a heat pump system for supplying heat and cold for rectification, which comprises a cold supply pipeline connected with the top of a rectifying tower, the cold supply pipeline is connected with a circulating pump, the circulating pump is connected with a refrigerant storage tank, the top of the rectifying tower is provided with a return pipeline, and the return pipeline is sequentially connected with a secondary heat exchanger, a primary heat exchanger and a refrigerant buffer tank. The refrigerant buffer tank is connected with an ammonia ice machine, the ammonia ice machine is sequentially connected with a cooler, a primary heat exchanger and a tower kettle of a rectifying tower through a heat supply pipeline, the tower kettle of the rectifying tower is connected to a secondary heat exchanger, and the secondary heat exchanger is connected to the refrigerant storage tank. According to the heat pump system disclosed by the utility model, circulating heat exchange between the tower kettle and the tower top is realized, the rectification working condition is kept stable by utilizing self-control flow regulation and ice maker energy consumption regulation, the original refrigerating unit and hot water tank are replaced, the electric energy consumption is greatly reduced, and the consumption of water resources and steam resources is reduced.

Description

Technical Field

[0001] This utility model relates to the field of heat pump system technology, and in particular to a heat pump system for heating and cooling distillation. Background Technology

[0002] The purification of high-purity ammonia utilizes a distillation column for separation. Distillation is a production process that separates heavy and light components based on their different boiling points. A distillation column mainly consists of three parts: a bottom reboiler, trays, and a top cooler. During distillation, the ammonia-containing feedstock is heated in the reboiler to form a gas, which is then condensed. Ammonia water enters from the top of the distillation column and exchanges heat with the rising steam from the reboiler. Because ammonia and water have different boiling points, the ammonia gas evaporates first. The high-concentration ammonia water vapor is condensed into high-concentration ammonia water in the top condenser and then discharged, yielding high-purity ammonia. The distillation process requires continuous vaporization and liquefaction. Circulating hot water is used to provide heat to the column bottom, while a refrigeration unit provides cooling water to the top of the column. Stable operation of the distillation process is ensured by regulating the temperature and flow rate of the hot and cold water.

[0003] However, the distillation process consumes a lot of energy. This is because the heat source for the distillation column bottom comes from the hot water in the hot water tank, which is mainly heated by steam. The cold water at the top of the column comes from the refrigeration unit, which cools the room temperature water. Therefore, during the distillation of high-purity ammonia, the equipment is constantly releasing heat on one side and constantly heating on the other. This results in a large amount of steam and electricity consumption during the distillation process, leading to high energy consumption of the overall distillation process, which is not conducive to cost reduction and efficiency improvement for enterprises. Utility Model Content

[0004] To address the technical problem in existing distillation processes where one side of the equipment continuously releases heat while the other side continuously heats, resulting in significant steam and electricity consumption and high overall energy consumption, which hinders cost reduction and efficiency improvement for enterprises, this utility model provides the following technical solution.

[0005] This utility model discloses a heat pump system for heating and cooling distillation, including a cooling pipeline connected to the top of a distillation column, a circulating pump connected to the circulating pump connected to a refrigerant storage tank, a reflux pipeline at the top of the distillation column, a secondary heat exchanger, a primary heat exchanger, and a refrigerant buffer tank connected in sequence to the reflux pipeline, an ammonia reflux machine connected to the refrigerant buffer tank, a cooler, a primary heat exchanger, and the bottom of the distillation column connected in sequence to the heating pipeline, the bottom of the distillation column connected to the secondary heat exchanger, and the secondary heat exchanger connected to the refrigerant storage tank.

[0006] As a further technical solution, an ammonia replenishment pipeline is also included, which is connected to the refrigerant storage tank.

[0007] As a further technical solution, the ammonia replenishment pipeline is connected to a vaporizer, and the vaporizer is connected to the refrigerant storage tank via a cooling auxiliary pipeline.

[0008] As a further technical solution, the vaporizer is connected in sequence to the first-stage heat exchanger and the bottom of the distillation column via a heating auxiliary medium pipeline.

[0009] As a further technical solution, the ammonia replenishment pipeline is connected to ammonia raw materials.

[0010] As a further technical solution, both the cooling pipeline and the heating pipeline are equipped with throttling valves.

[0011] The beneficial effects of this invention are as follows: The heat pump system of this invention utilizes ammonia, the raw material used in high-purity ammonia plants, as the medium. After compression by an ammonia refrigeration unit, the high-temperature gaseous ammonia is cooled by a cooler and then enters the distillation column reboiler for heat exchange after primary heat exchange, providing heat to the reboiler. The cooled liquid ammonia then returns to the refrigerant storage tank after secondary heat exchange. The liquid ammonia in the refrigerant storage tank is pumped to the top of the distillation column by a circulating pump, providing a cold source for the top of the distillation column through throttling vaporization heat absorption. The vaporized gaseous ammonia then passes through the primary and secondary heat exchangers and re-enters the ammonia refrigeration unit for compression via a refrigerant buffer tank, achieving circulating heat exchange between the column reboiler and the top. Stable distillation conditions are maintained through automatic flow control and refrigeration unit energy consumption regulation. This system replaces the original refrigeration unit and hot water tank, significantly reducing electricity consumption and minimizing the consumption of water and steam resources. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of a heat pump system for distillation cooling and heating according to this utility model;

[0013] In the diagram: 1-Distillation column; 2-Refrigerant storage tank; 3-Circulating pump; 4-Refrigerant buffer tank; 5-Ammonia ice machine; 6-Cooler; 7-First-stage heat exchanger; 8-Second-stage heat exchanger; 9-Vaporizer; a-Ammonia replenishment pipeline; b-Cooling pipeline; c-Return pipeline; d-Heating pipeline; e-Cooling auxiliary refrigerant pipeline; f-Heating auxiliary refrigerant pipeline. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0015] In the description of this utility model, it should be understood that the terms "upper" and "lower" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0016] like Figure 1 As shown, this utility model discloses a heat pump system for heating and cooling distillation, including a cooling pipeline b connected to the top of a distillation column 1. The cooling pipeline b is connected to a circulation pump 3, and the circulation pump 3 is connected to a refrigerant storage tank 2. The refrigerant in the refrigerant storage tank 2 is raw material liquid ammonia. The circulation pump 3 pumps the liquid ammonia in the refrigerant storage tank 2 through the cooling pipeline b to the top of the distillation column 1. By using a throttling vaporization heat absorption method, a cold source is provided to the top of the distillation column 1, eliminating the need for chilled water as the refrigerant and reducing water consumption.

[0017] In a preferred embodiment, the distillation column 1 is provided with a reflux line c at the top. The reflux line c is sequentially connected to a secondary heat exchanger 8, a primary heat exchanger 7, and a refrigerant buffer tank 4. The reflux line c starts at the top of the column, passes through the secondary heat exchanger 8 and the primary heat exchanger 7, and ends at the refrigerant buffer tank 4. The refrigerant buffer tank 4 is used to buffer liquid ammonia and is connected to an ammonia refrigeration unit 5. After the liquid ammonia provides a cooling source for the top of the distillation column 1 by throttling vaporization and heat absorption at the top of the column, the vaporized ammonia gas passes through the secondary heat exchanger 8 and the primary heat exchanger 7, enters the ammonia refrigeration unit 5 through the refrigerant buffer tank 4 for compression, and then flows to the bottom of the distillation column 1 through the heating line d, realizing the circulating heat exchange between the bottom and the top of the distillation column 1.

[0018] Specifically, the ammonia refrigeration unit 5 is connected in sequence to the cooler 6, the first-stage heat exchanger 7, and the bottom of the distillation column 1 via the heating pipeline d. The heating pipeline d starts at the ammonia refrigeration unit 5, passes through the cooler 6 and the first-stage heat exchanger 7, and ends at the bottom of the distillation column 1 to supply heat to the bottom of the column.

[0019] In a preferred embodiment, the reboiler of the distillation column 1 is connected to a secondary heat exchanger 8, which is connected to a refrigerant storage tank 2. The liquid ammonia, after being heated and cooled by the reboiler, is then cooled again by the secondary heat exchanger 8 and sent to the refrigerant storage tank 2. The liquid ammonia in the refrigerant storage tank 2 is then pumped to the top of the distillation column 1 through the cooling pipeline b by the circulating pump 3, thereby providing a cold source for the top of the distillation column 1 by means of throttling vaporization heat absorption.

[0020] In a preferred embodiment, the heat pump system of this invention further includes an ammonia replenishment line a, which is used to replenish raw material ammonia. The ammonia replenishment line a is connected to the refrigerant storage tank 2 and can directly replenish liquid ammonia to the refrigerant storage tank 2. Simultaneously, the ammonia replenishment line a is also connected to a vaporizer 9, which is connected to the refrigerant storage tank 2 via a cooling auxiliary refrigerant line e. The vaporized ammonia, at a suitable temperature, can be supplied to the refrigerant storage tank 2 again.

[0021] In a preferred embodiment, the vaporizer 9 is connected in sequence to the first-stage heat exchanger 7 and the bottom of the distillation column 1 via the auxiliary heating medium pipeline f. At this time, the highly vaporized high-temperature ammonia gas can be directly heat-exchanged by the first-stage heat exchanger 7 and then enter the bottom of the distillation column 1 to provide heat to the bottom of the column.

[0022] All the aforementioned pipelines are equipped with throttling valves for precise flow regulation and energy consumption control of the ammonia refrigeration unit 5, maintaining stable distillation operation. This system replaces the original refrigeration unit and hot water tank, significantly reducing electricity consumption and minimizing water and steam resource consumption.

[0023] The preferred embodiments and examples of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes or equivalent substitutions can be made without departing from the concept of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A heat pump system for heating and cooling distillation, characterized in that: The distillation column (1) includes a cooling pipeline (b) connected to the top of the column, a circulating pump (3) connected to the circulating pump (3) connected to a refrigerant storage tank (2), a reflux pipeline (c) provided at the top of the column, a secondary heat exchanger (8), a primary heat exchanger (7) and a refrigerant buffer tank (4) connected in sequence to the reflux pipeline (c), an ammonia reflux machine (5) connected to the refrigerant buffer tank (4), a cooler (6), a primary heat exchanger (7) and the bottom of the distillation column (1) connected in sequence to the heating pipeline (d), the bottom of the distillation column (1) connected to the secondary heat exchanger (8), and the secondary heat exchanger (8) connected to the refrigerant storage tank (2).

2. The heat pump system for heating and cooling distillation according to claim 1, characterized in that: It also includes an ammonia replenishment line (a) which is connected to the refrigerant storage tank (2).

3. The heat pump system for heating and cooling distillation according to claim 2, characterized in that: The ammonia replenishment line (a) is connected to a vaporizer (9), and the vaporizer (9) is connected to the refrigerant storage tank (2) via a cooling auxiliary media line (e).

4. The heat pump system for heating and cooling distillation according to claim 3, characterized in that: The vaporizer (9) is connected in sequence to the first-stage heat exchanger (7) and the bottom of the distillation column (1) via a heating auxiliary medium pipeline (f).

5. The heat pump system for heating and cooling distillation according to claim 2, characterized in that: The ammonia replenishment pipeline (a) is connected to ammonia feedstock.

6. The heat pump system for heating and cooling distillation according to claim 1, characterized in that: Both the cooling pipeline (b) and the heating pipeline (d) are equipped with throttling valves.

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