Liquid air production device

Abstract

The utility model relates to a liquid air production device which comprises a raw material air compression system, an air cooling and drying system, a circulating pressurization system, an expansion refrigeration system, a heat exchange cold box and a liquid air storage tank. The raw material air compression system comprises a gas feeding air compressor and an air cooler; the air cooling and drying system comprises a freezing dryer and an adsorption dryer; and the circulating supercharging system comprises a circulating supercharger and a supercharging cooler. According to the production method, efficient production of liquid air is achieved through the steps of multi-stage compression, cooling, drying, pressurization, expansion refrigeration and the like. By optimizing energy utilization, low-temperature air cooling capacity is recycled, compression work and power consumption are saved, and the production cost is remarkably reduced. The device is suitable for the fields of energy storage, metal smelting, precision manufacturing and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of air liquefaction and relates to a production device for liquid air. Background Art

[0002] Liquid air is the liquid form of air, referred to as liquid air. Because it is a multi-component mixture, it has different boiling points and unstable purity. In the field of air separation, it only exists as an intermediate product in the process and has not been widely used. With the rapid development of new quality productivity in my country, in-depth research and exploration of liquid air energy storage and compressed air energy storage, liquid air has become an ideal carrier for energy storage due to its low temperature and huge vaporization expansion coefficient, and the maturity of transportation and storage technology.

[0003] The inherent oxygen content of liquid air also has application scenarios for improving the efficiency of metal smelting and oxygen-enriched combustion. Its inherent dryness and cleanness have led to an increase in its application scenarios in precision manufacturing and dust-free workshops. The heat absorption potential of liquid air vaporization and the mechanical work generated by expansion contain energy. Coupling the use of liquid air with the air separation unit, on the one hand, recovers the coldness of the liquid air to replace expansion refrigeration, saving the compression work of part of the expanded air used for refrigeration but not involved in distillation; on the other hand, the entry of liquid air also increases the raw air required for separation, saving some of the electricity used for raw air compression. Therefore, with the increase in the application scenarios of liquid air, low-cost liquid air manufacturing has become increasingly important. Utility Model Content

[0004] In view of this, the purpose of the present invention is to solve the above problems and provide a liquid air production device.

[0005] In order to achieve the above object, the utility model provides the following technical solutions:

[0006] A liquid air production device, comprising a raw air compression system, an air cooling and drying system, a circulating pressurization system, an expansion refrigeration system, a heat exchange cold box, and a liquid air storage tank;

[0007] The raw air compression system includes a feed air compressor and an air cooler; the air cooling and drying system includes a cold dryer and an adsorption dryer; the circulating boosting system includes a circulating booster and a boosting cooler;

[0008] The expansion refrigeration system comprises a hot-end booster turbine expander, a hot-end booster cooler, a cold-end booster turbine expander, and a cold-end booster cooler; the cold-end booster turbine expander is provided with two groups of inlets and outlets, namely, a cold-end booster air inlet and a cold-end booster air outlet, and a cold-end expansion air inlet and a cold-end expansion air outlet; the hot-end booster turbine expander is provided with two groups of inlets and outlets, namely, a hot-end booster air inlet and a hot-end booster air outlet, and a hot-end expansion air inlet and a hot-end expansion air outlet;

[0009] The heat exchange cold box includes a hot-end heat exchanger, a cold-end heat exchanger, and a subcooler; the hot-end heat exchanger is provided with four groups of inlets and outlets, namely, a first inlet and a first outlet of the hot-end heat exchange, a second inlet and a second outlet of the hot-end heat exchange, a third inlet and a third outlet of the hot-end heat exchange, and a fourth inlet and a fourth outlet of the hot-end heat exchange; the cold-end heat exchanger is provided with three groups of inlets and outlets, namely, a first inlet and a first outlet of the cold-end heat exchange, a second inlet and a second outlet of the cold-end heat exchange, and a third inlet and a third outlet of the cold-end heat exchange; a side outlet is also led out from the middle position of the first inlet and the first outlet of the cold-end heat exchange; the subcooler is provided with two groups of inlets and outlets, namely, a first subcooling inlet and a first subcooling outlet, and a second subcooling inlet and a second subcooling outlet;

[0010] The air-feeding air compressor, air cooler, cold dryer, adsorption dryer, circulating supercharger, and supercharge cooler are connected in series in sequence, and the outlet of the supercharge cooler is divided into two routes:

[0011] One path is connected to the cold end boost air inlet, the cold end boost air outlet is connected to the hot end boost air inlet after passing through the cold end boost cooler, the hot end boost air outlet is connected to the hot end heat exchange first inlet after passing through the hot end boost cooler, the hot end heat exchange first outlet is connected to the hot end expansion air inlet, the hot end expansion air outlet is connected to the hot end heat exchange third inlet, and the hot end heat exchange third outlet is connected to the inlet of the circulating booster;

[0012] The other path is connected to the second inlet of the hot end heat exchange, the second outlet of the hot end heat exchange is connected to the first inlet of the cold end heat exchange, the first outlet of the cold end heat exchange is connected to the first inlet of the supercooling, the first outlet of the supercooling is divided into two paths, one path is connected to the liquid air storage tank, and the other path is connected to the second inlet of the supercooling, the second outlet of the supercooling is connected to the third inlet of the cold end heat exchange; the third outlet of the cold end heat exchange is connected to the fourth inlet of the hot end heat exchange; the fourth outlet of the hot end heat exchange is connected to the adsorption dryer to provide analytical gas to the adsorption dryer;

[0013] The side end outlet is communicated with the cold end expansion air inlet, the cold end expansion air outlet is communicated with the cold end heat exchange second inlet, and the cold end heat exchange second outlet is communicated with the hot end heat exchange third inlet.

[0014] Furthermore, throttle valves are provided between the first outlet of the cold end heat exchange and the first inlet of the supercooling, between the first outlet of the supercooling and the liquid-air storage tank, and between the first outlet of the supercooling and the second inlet of the supercooling.

[0015] Furthermore, the liquid-air storage tank is provided with a storage tank steam outlet, and the storage tank steam outlet is connected to the third inlet of the cold end heat exchange.

[0016] Furthermore, the circulating supercharger is a piston supercharger.

[0017] Furthermore, the hot end heat exchanger, the cold end heat exchanger and the subcooler are all aluminum alloy plate-fin heat exchangers, and are arranged in three stages in series in the heat exchange cold box.

[0018] The beneficial effects of the utility model are:

[0019] 1. The utility model adopts a combination of multi-stage compression, expansion refrigeration and high-efficiency heat exchangers, uses a booster turbine expansion mechanism to extract cooling capacity, effectively matches the boost volume with the expansion volume, and improves the expansion refrigeration efficiency. The heat exchange part is divided into three sections, including a hot end heat exchanger, a cold end heat exchanger and a subcooler, and optimizes and adjusts the temperature before and after the expander. The energy utilization efficiency in the air liquefaction process is optimized, the production efficiency of liquid air is significantly improved, and the production cost of liquid air is reduced.

[0020] 2. The utility model utilizes the period of low electricity price to produce liquid air, which has the function of regulating the power grid.

[0021] 3. The utility model utilizes supercooled gas and natural evaporated gas as analytical gas for the adsorption dryer, thereby saving the compression cost of the raw gas.

[0022] 4. After the air is liquefied by the cold end heat exchanger, the utility model does not set a flash evaporator for gas-liquid separation to maintain the stability of the liquid-air components.

[0023] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and will be apparent to those skilled in the art based on the following examination and research, or can be taught from the practice of the present invention to some extent. The objectives and other advantages of the present invention can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be described in detail below in conjunction with the accompanying drawings, in which:

[0025] Figure 1 This is a schematic diagram of the production device of liquid air in the utility model.

[0026] Figure numerals: 1-feed air compressor; 2-air cooler; 3-cold dryer; 4-adsorption dryer; 5-circulation booster; 6-boost cooler; 7-cold end booster turbine expander; 8-cold end booster cooler; 9-hot end booster turbine expander; 10-hot end booster cooler; 11-hot end heat exchanger; 12-cold end heat exchanger; 13-subcooler; 14-liquid air storage tank; 21-air inlet; 22-air outlet; 23-cooling water inlet; 24-cooling water outlet; 41-adsorption dryer air inlet ;42-dryer air outlet;43-dryer analytical air inlet;44-dryer analytical air outlet;61-circulating pressurized air inlet;62-circulating pressurized air outlet;63-cooling water inlet;64-cooling water outlet;71-cold end pressurized air inlet;72-cold end pressurized air outlet;73-cold end expansion air inlet;74-cold end expansion air outlet;81-cold end cooling air inlet;82-cold end cooling air outlet;83-cooling water inlet;84-cooling water outlet;91-hot end pressurized air Air inlet; 92-hot end boost air outlet; 93-hot end expansion air inlet; 94-hot end expansion air outlet; 101-hot end cooling air inlet; 102-hot end cooling air outlet; 103-cooling water inlet; 104-cooling water outlet; 111-hot end heat exchange first inlet; 112-hot end heat exchange first outlet; 113-hot end heat exchange second inlet; 114-hot end heat exchange second outlet; 115-hot end heat exchange third outlet; 116-hot end heat exchange third inlet; 117-hot end heat exchange fourth outlet 118-hot end heat exchange fourth inlet; 120-cold end heat exchange first outlet; 121-cold end heat exchange first inlet; 122-side end outlet; 123-cold end heat exchange second outlet; 124-cold end heat exchange second inlet; 125-cold end heat exchange third outlet; 126-cold end heat exchange third inlet; 131-subcooling first inlet; 132-subcooling first outlet; 133-subcooling second outlet; 134-subcooling second inlet; 141-storage tank inlet; 142-storage tank vapor outlet; 53-storage tank liquid air outlet. DETAILED DESCRIPTION

[0027] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. The following embodiments and the features in the embodiments can be combined with each other without conflict.

[0028] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present utility model. In order to better illustrate the embodiments of the present utility model, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back" and the like indicate directions or positional relationships, they are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] See also Figure 1 , which is a liquid air production device, including a raw air compression system, an air cooling and drying system, a circulating pressurization system, an expansion refrigeration system, a heat exchange cold box, and a liquid air storage tank 14;

[0031] The raw air compression system includes a feed air compressor 1 and an air cooler 2; the air cooling and drying system includes a cold dryer 3 and an adsorption dryer 4; the circulating pressurization system includes a circulating supercharger 5 and a supercharged cooler 6; the air cooler 2 is provided with two groups of inlets and outlets, namely, an air inlet 21 and an air outlet 22, a cooling water inlet 23 and a cooling water outlet 24; the adsorption dryer 4 is provided with two groups of inlets and outlets, namely, an adsorption dryer air inlet 41 and an adsorption dryer air outlet 42, an adsorption dryer analytical gas inlet 43 and an adsorption dryer analytical gas outlet 44. The supercharged cooler 6 is provided with a circulating supercharged air inlet 61, a circulating supercharged air outlet 62, a cooling water inlet 63 and a cooling water outlet 64.

[0032] The expansion refrigeration system includes a hot-end booster turbine expander 9, a hot-end booster cooler 10, a cold-end booster turbine expander 7, and a cold-end booster cooler 8; the cold-end booster turbine expander 7 is provided with two groups of inlets and outlets, namely, a cold-end booster air inlet 71 and a cold-end booster air outlet 72, and a cold-end expansion air inlet 73 and a cold-end expansion air outlet 74; the hot-end booster turbine expander 9 is provided with two groups of inlets and outlets, namely, a hot-end booster air inlet 91 and a hot-end booster air outlet 92, and a hot-end expansion air inlet 93 and a hot-end expansion air outlet 94; the hot-end booster cooler 10 is provided with two groups of inlets and outlets, namely, a hot-end cooling air inlet 101 and a hot-end cooling air outlet 102, a cooling water inlet 103 and a cooling water outlet 104; the cold-end booster cooler 8 is provided with two groups of inlets and outlets, namely, a cold-end cooling air inlet 81 and a cold-end cooling air outlet 82, a cooling water inlet 83 and a cooling water outlet 84;

[0033] The heat exchange cold box includes a hot end heat exchanger 11, a cold end heat exchanger 12, and a subcooler 13; the hot end heat exchanger 11 is provided with four groups of inlets and outlets, namely, a hot end heat exchange first inlet 111 and a hot end heat exchange first outlet 112, a hot end heat exchange second inlet 113 and a hot end heat exchange second outlet 114, a hot end heat exchange third inlet 116 and a hot end heat exchange third outlet 115, a hot end heat exchange fourth inlet 118 and a hot end heat exchange fourth outlet 117; the cold end heat exchanger 12 is provided with three groups of inlets and outlets, namely, a cold end heat exchange first inlet 121 and a cold end heat exchange first outlet 11 20, a second cold-end heat exchange inlet 124 and a second cold-end heat exchange outlet 123, a third cold-end heat exchange inlet 126 and a third cold-end heat exchange outlet 125; a side outlet 122 is also led out from the middle position between the first cold-end heat exchange inlet 121 and the first cold-end heat exchange outlet 120; two groups of inlets and outlets are arranged on the subcooler 13, namely, a first subcooling inlet 131 and a first subcooling outlet 132, a second subcooling inlet 134 and a second subcooling outlet 133; a storage tank inlet 141, a storage tank vapor outlet 142, and a storage tank liquid-air outlet 53 are arranged on the liquid-air storage tank 14.

[0034] The air-feeding air compressor 1, air cooler 2, cold dryer 3, adsorption dryer 4, circulating booster 5, boost cooler 6 are connected in series in sequence, and the outlet of boost cooler 6 is divided into two routes:

[0035] One path is connected to the cold end boost air inlet, the cold end boost air outlet 72 is connected to the hot end boost air inlet 91 after passing through the cold end boost cooler 8, the hot end boost air outlet 92 is connected to the hot end heat exchange first inlet 111 after passing through the hot end boost cooler 10, the hot end heat exchange first outlet 112 is connected to the hot end expansion air inlet 93, the hot end expansion air outlet 94 is connected to the hot end heat exchange third inlet 116, and the hot end heat exchange third outlet 115 is connected to the inlet of the circulating supercharger 5;

[0036] The other path is connected to the hot end heat exchange second inlet 113, the hot end heat exchange second outlet 114 is connected to the cold end heat exchange first inlet 121, the cold end heat exchange first outlet 120 is connected to the supercooling first inlet 131, the supercooling first outlet 132 is divided into two paths, one path is connected to the storage tank inlet, and the other path is connected to the supercooling second inlet 134, the supercooling second outlet 133 is connected to the cold end heat exchange third inlet 126; the cold end heat exchange third outlet 125 is connected to the hot end heat exchange fourth inlet 118; the hot end heat exchange fourth outlet 117 is connected to the adsorption dryer 4 to provide the adsorption dryer 4 with analytical gas;

[0037] The side end outlet 122 is communicated with the cold end expansion air inlet 73 , the cold end expansion air outlet 74 is communicated with the cold end heat exchange second inlet 124 , and the cold end heat exchange second outlet 123 is communicated with the hot end heat exchange third inlet 116 .

[0038] A throttle valve V1 is provided between the first supercooling outlet 132 and the second supercooling inlet 134 , a throttle valve V2 is provided between the first supercooling outlet 132 and the liquid-air storage tank, and a throttle valve V3 is provided between the cold-end heat exchange first outlet 120 and the first supercooling inlet 131 .

[0039] The liquid-air storage tank 14 is provided with a storage tank steam outlet 142 , which is communicated with the cold end heat exchange third inlet 126 .

[0040] The air supply air compressor 1 is a screw compressor, and the circulating supercharger 5 is a piston supercharger to adapt to frequent starts and stops.

[0041] The hot end heat exchanger 11, the cold end heat exchanger 12 and the subcooler 13 are all aluminum alloy plate-fin heat exchangers, and are arranged in three stages in series in the heat exchange cold box.

[0042] The liquid air production device in this embodiment is used to produce liquid air, and the production process is as follows:

[0043] The air is pressurized to 0.5MPa by the air compressor 1 to obtain medium-pressure air, which enters the air cooler 2; the cooled medium-pressure air is further cooled to 10°C by the cold dryer 3, and then the moisture and carbon dioxide are removed by the adsorption dryer 4; the dry and clean medium-pressure air enters the circulating booster 5 for further pressurization to obtain 2.9MPa high-pressure air, and then is divided into two routes:

[0044] All the way, it enters the cold end boost air inlet 71, after being boosted, it is cooled by the cold end boost air cooler 8 and then enters the hot end boost air inlet 91, after being boosted to 4.6MPa again, it is led out from the hot end boost air outlet 92, after being cooled by the hot end boost air cooler 10, it enters the hot end heat exchange first inlet 111 again, after being cooled, it is led out from the hot end heat exchange first outlet 112, and then enters the hot end expansion air inlet 93, after expansion and refrigeration, it is led out from the hot end expansion air outlet 94, and the expanded medium-pressure air returns to the hot end heat exchange third inlet 116;

[0045] The other path directly enters the hot end heat exchange second inlet 113, is led out from the hot end heat exchange second outlet 114 after cooling, and then enters the cold end heat exchange first inlet 121. After cooling, it is divided into two paths in the middle of the cold end heat exchanger 12:

[0046] One path is led out from the side end outlet 122 to connect to the cold end expansion air inlet 73, and the medium-pressure air obtained after expansion and refrigeration is led out from the cold end expansion air outlet 74, enters the cold end heat exchange second inlet 124, and is led out from the cold end heat exchange second outlet 123 after being reheated by the cold end heat exchanger 12, and after merging with the medium-pressure air led out from the hot end expansion air outlet 94, they are reheated to room temperature by the hot end heat exchanger 11 and then return to the inlet of the circulating booster 5;

[0047] The other high-pressure liquid air after being cooled and liquefied is led out from the first outlet 120 of the cold end heat exchange, throttled to 0.55MPa by the throttle valve V3, and then enters the first subcooling inlet 131, and is led out from the first subcooling outlet 132 after subcooling. The subcooled liquid air is divided into two parts. One part is throttled to 0.03MPa by the throttle valve V1 and then returns to the second subcooling inlet 134, and is led out from the second subcooling outlet 133 after vaporization and reheating, and then enters the third inlet 126 of the cold end heat exchange, and is led out from the third outlet 125 of the cold end heat exchange after reheating, and then enters the fourth inlet 118 of the hot end heat exchange, and continues to be reheated to room temperature, and is led out from the fourth outlet 117 of the hot end heat exchange to the adsorption dryer 4, and is discharged into the atmosphere after analysis; the other part is sent to the liquid air storage tank as a liquid air product.

[0048] In this embodiment, the circulating booster 5 adopts variable step start to reduce the impact of start-up on the power grid. The liquid air production device operates during the period of low electricity price and stops during the period of high electricity price.

[0049] The raw air used in this embodiment is 7500Nm 3 / h, 0.098MPa. The obtained product liquid air: 5000Nm 3 / h (converted to gas state).

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the utility model.

Claims

1. A liquid air production device, characterized in that: Including raw air compression system, air cooling and drying system, circulating pressurization system, expansion refrigeration system, heat exchange cold box, liquid air storage tank; The raw air compression system includes a feed air compressor and an air cooler; the air cooling and drying system includes a cold dryer and an adsorption dryer; the circulating boosting system includes a circulating booster and a boosting cooler; The expansion refrigeration system comprises a hot-end booster turbine expander, a hot-end booster cooler, a cold-end booster turbine expander, and a cold-end booster cooler; the cold-end booster turbine expander is provided with two groups of inlets and outlets, namely, a cold-end booster air inlet and a cold-end booster air outlet, and a cold-end expansion air inlet and a cold-end expansion air outlet; the hot-end booster turbine expander is provided with two groups of inlets and outlets, namely, a hot-end booster air inlet and a hot-end booster air outlet, and a hot-end expansion air inlet and a hot-end expansion air outlet; The heat exchange cold box includes a hot-end heat exchanger, a cold-end heat exchanger, and a subcooler; the hot-end heat exchanger is provided with four groups of inlets and outlets, namely, a first inlet and a first outlet of the hot-end heat exchange, a second inlet and a second outlet of the hot-end heat exchange, a third inlet and a third outlet of the hot-end heat exchange, and a fourth inlet and a fourth outlet of the hot-end heat exchange; the cold-end heat exchanger is provided with three groups of inlets and outlets, namely, a first inlet and a first outlet of the cold-end heat exchange, a second inlet and a second outlet of the cold-end heat exchange, and a third inlet and a third outlet of the cold-end heat exchange; a side outlet is also led out from the middle position of the first inlet and the first outlet of the cold-end heat exchange; the subcooler is provided with two groups of inlets and outlets, namely, a first subcooling inlet and a first subcooling outlet, and a second subcooling inlet and a second subcooling outlet; The air-feeding air compressor, air cooler, cold dryer, adsorption dryer, circulating supercharger, and supercharge cooler are connected in series in sequence, and the outlet of the supercharge cooler is divided into two routes: One path is connected to the cold end boost air inlet, the cold end boost air outlet is connected to the hot end boost air inlet after passing through the cold end boost cooler, the hot end boost air outlet is connected to the hot end heat exchange first inlet after passing through the hot end boost cooler, the hot end heat exchange first outlet is connected to the hot end expansion air inlet, the hot end expansion air outlet is connected to the hot end heat exchange third inlet, and the hot end heat exchange third outlet is connected to the inlet of the circulating booster; The other path is connected to the second inlet of the hot end heat exchange, the second outlet of the hot end heat exchange is connected to the first inlet of the cold end heat exchange, the first outlet of the cold end heat exchange is connected to the first inlet of the supercooling, the first outlet of the supercooling is divided into two paths, one path is connected to the liquid air storage tank, and the other path is connected to the second inlet of the supercooling, the second outlet of the supercooling is connected to the third inlet of the cold end heat exchange; the third outlet of the cold end heat exchange is connected to the fourth inlet of the hot end heat exchange; the fourth outlet of the hot end heat exchange is connected to the adsorption dryer to provide analytical gas to the adsorption dryer; The side end outlet is communicated with the cold end expansion air inlet, the cold end expansion air outlet is communicated with the cold end heat exchange second inlet, and the cold end heat exchange second outlet is communicated with the hot end heat exchange third inlet.

2. The liquid air production device according to claim 1, characterized in that: Throttle valves are arranged between the first outlet of the cold end heat exchange and the first inlet of the subcooling, between the first outlet of the subcooling and the liquid air storage tank, and between the first outlet of the subcooling and the second inlet of the subcooling.

3. The liquid air production device according to claim 1, characterized in that: The liquid-air storage tank is provided with a storage tank steam outlet, and the storage tank steam outlet is communicated with the third inlet of the cold end heat exchange.

4. The liquid air production device according to claim 1, characterized in that: The circulating booster is a piston booster.

5. The liquid air production device according to claim 1, characterized in that: The hot end heat exchanger, the cold end heat exchanger and the subcooler are all aluminum alloy plate-fin heat exchangers, and are arranged in three sections in series in the heat exchange cold box.

Images