Ice making and storing integrated device and method based on LNG cold energy gradient utilization

Abstract

The invention discloses an ice making and storing integrated device and method based on LNG cold energy gradient utilization. The device comprises an LNG gasification system, a cold energy recovery system, a slice ice-block ice collaborative ice making system and an ice storage integrated system. According to the LNG gasification system, LNG exchanges heat with a multi-stage refrigerant, so that the cold energy utilization efficiency is improved; according to the cold energy recovery system, LNG cold energy is used for ice making and waste cold recovery in a grading mode through a secondary refrigerant, and the cold energy utilization efficiency is improved by using low-temperature water as a raw material; according to the slice ice-block ice collaborative ice-making system, a two-stage heat exchange mode of firstly making slice ice and then making block ice is adopted, so that the ice-making period is shortened; according to the ice storage integrated system, the ice mold in the novel ice making pool has the ice making function and the ice storage function, and the occupied area is saved. The system has the advantages of high automation degree, small occupied area, low ice storage cost, high cold energy utilization rate, high ice making efficiency and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquefied natural gas (LNG) cold energy recovery, and in particular relates to an integrated ice making and ice storage device and method based on the cascade utilization of LNG cold energy. Background Art

[0002] In recent years, the efficient recovery and utilization of liquefied natural gas (LNG) cold energy has become an important research direction in the energy field. At present, most LNG cold energy utilization technologies only focus on the design and optimization of the process, and do not take into account the problem that the LNG ice-making site occupies too large an area and the ice-making time is long, and there is a problem of poor adaptability to changes in working conditions; secondly, traditional LNG cold energy ice-making processes mostly use electric compression refrigeration or direct cooling ice-making technology, which has problems such as low cold energy utilization, insufficient ice-making efficiency, and sensitivity to fluctuations in LNG vaporization parameters. For example, the direct cooling ice-making process is easily affected by fluctuations in LNG vaporization pressure and temperature, resulting in decreased ice-making stability; and although traditional calcium chloride solution pool ice-making can alleviate fluctuations, it has defects such as long ice-making cycle and low cold energy transfer efficiency. In addition, a single refrigerant system is difficult to adapt to the needs of cold energy cascade utilization in a wide temperature range, resulting in cold energy. The loss rate is higher.

[0003] Among the existing ice-making schemes, such as "an LNG cold energy recovery ice-making system (CN 211120163 U)", it does not involve the actual ice-making process and has low adaptability to complex working conditions. "A high-coupling LNG cold energy ice-making process and device (CN114322384A)" creatively integrates LNG vaporization cold energy, calcium chloride solution ice-making and cold storage pre-cooling system, realizing three-level utilization of cold energy, but does not solve the problem of long ice-making cycle, and the number of valves used in the process is large, and there is no corresponding valve control system. Although the ice-making scheme disclosed in CN119573301A can make ice from brine through LNG cold energy, it has the problems of long ice-making time, slow heat transfer speed, and no corresponding solution to the fluctuation of LNG vaporization amount. Summary of the Invention

[0004] To address at least one of the problems with the existing technology, the present invention provides an integrated ice-making and ice-storage device and method based on the cascaded utilization of LNG cold energy. These devices feature a small footprint, short ice-making times, and long-term operation. They also boast a high degree of automation and considerable economic benefits, making ice slurry from a flake ice machine and a novel ice-making tank in series. This system utilizes a flake ice machine and a novel ice-making tank to mix flake ice with low-temperature water, resulting in ice slurry. This system offers advantages such as a small footprint, low ice storage costs, high cold energy utilization, and high ice-making efficiency.

[0005] In order to achieve the purpose of the present invention, the present invention provides an integrated ice making and ice storage device based on the cascade utilization of LNG cold energy, comprising:

[0006] An LNG gasification system, which is used to gasify LNG and release the cold energy contained in LNG, includes an LNG storage tank, a first heat exchanger, and an air-temperature vaporizer; the input ends of the first heat exchanger and the air-temperature vaporizer are both connected to the output end of the LNG storage tank, and the first heat exchanger and the air-temperature vaporizer are connected;

[0007] A cold energy recovery system, which is used to recover cold energy generated by LNG vaporization and supply cooling to the flake ice-block ice system. The cold energy recovery system includes a refrigerant tank and a second heat exchanger. The input end of the refrigerant tank is connected to the output end of the integrated ice making and storage system. The output end of the refrigerant tank is connected to the tube-side input end of the second heat exchanger. The shell-side input end of the second heat exchanger is connected to the shell-side output end of the first heat exchanger.

[0008] A flake ice-block ice collaborative ice-making system is used to accelerate ice production and regulate LNG gas volume fluctuations. The flake ice-block ice collaborative ice-making system includes a flake ice machine, the input end of which is connected to the output end of the second heat exchanger tube to supply cooling to the flake ice machine, and the flake ice machine is used to produce flake ice.

[0009] An integrated ice-making and ice-storage system is provided, which is used to produce ice blocks and simultaneously store ice. The integrated ice-making and ice-storage system includes a new ice-making pool, an ice mold, a block quality detector, and an ultrasonic transmitter. The ice mold is arranged inside the new ice-making pool, and low-temperature water can flow into the ice mold. The input end of the new ice-making pool is connected to the output end of the flake ice machine so that the flake ice produced by the flake ice machine can combine with the low-temperature water in the ice mold to accelerate ice formation. The ice quality detector is used to detect ice blocks in the ice mold. The ice quality detector is connected to the ultrasonic transmitter, and the ultrasonic transmitter is used to separate the ice blocks from the ice mold.

[0010] Furthermore, the cold energy recovery system also includes a third heat exchanger and a fourth heat exchanger; the tube side input end of the third heat exchanger is connected to the tube side output end of the first heat exchanger; the tube side input end of the fourth heat exchanger is connected to the shell side output end of the third heat exchanger.

[0011] Furthermore, it also includes a pressure regulator and a meter; the pressure regulator is connected to the third heat exchanger and the meter.

[0012] Furthermore, a first regulating valve is installed between the LNG storage tank and the first heat exchanger to regulate the LNG flow rate; a pressure regulating valve is installed between the third heat exchanger and the pressure regulator to regulate the natural gas flow rate. The third heat exchanger is used to reheat the NG gas after heat exchange to above 0°C, facilitating its subsequent input into the user pipeline network.

[0013] Furthermore, the first heat exchanger exchanges heat between LNG and the primary refrigerant. After the primary refrigerant cools down, it enters the second heat exchanger for heat exchange. The second heat exchanger exchanges heat between the primary refrigerant and the secondary refrigerant. After the secondary refrigerant cools down, it enters the integrated ice flake and block ice system to supply cold energy.

[0014] Furthermore, the heat exchange medium of the first heat exchanger is R507 refrigerant, and heat is exchanged between LNG and R507 refrigerant. After the temperature of the R507 refrigerant is reduced, it enters the second heat exchanger for heat exchange.

[0015] Furthermore, the heat exchange medium of the second heat exchanger is a salt solution, preferably a calcium chloride solution, and heat is exchanged between R507 and the calcium chloride solution. After the temperature of the calcium chloride solution is reduced, it enters the ice making and storage system to supply cold energy.

[0016] The calcium chloride solution buffer tank is used to stabilize the calcium chloride solution level of the novel ice making pool.

[0017] Furthermore, the flake ice machine is used in series with the new ice making pool. After the flake ice is produced, it can directly enter the new ice making pool and mix with supercooled water to accelerate the ice making process.

[0018] Furthermore, the flake ice machine can output part of the flake ice for sale when the LNG flow rate is large, thereby ensuring stable and continuous ice making in the new ice making pool.

[0019] The cold energy recovery system further includes a compressor, the input of which is connected to the output of the second heat exchanger's tube side, and the output of which is connected to the new ice-making pool. When the LNG flow rate is low, the compressor can use electricity to supplement the cooling capacity of the new ice-making pool, ensuring stable and continuous ice production.

[0020] Furthermore, the flake ice-block ice collaborative ice making system also includes a water separator, the input end of the water separator is connected to the output end of the novel ice making pool, and the output end of the water separator is connected to the output end of the refrigerant storage tank.

[0021] Furthermore, low-temperature water is introduced into the ice mold through a water adder, and the input end of the water adder is connected to the output end of the shell side of the fourth heat exchanger.

[0022] The water feeder is used to supply low-temperature water to the new ice-making pool, ensuring that the low-temperature water enters the pool at a consistent temperature. This ensures that ice cubes in the same row of ice molds are produced at the same time, achieving continuous batch ice production. The new ice-making pool is used for both ice production and storage, achieving integrated ice production and storage, reducing floor space by 50% compared to traditional ice-making pools.

[0023] Furthermore, the new ice-making pool structure is lined with high-density polyethylene and supported by 316L stainless steel, forming a stable structure. It also achieves thermal insulation to reduce cold energy loss while reducing corrosion from calcium chloride solution and extending service life.

[0024] Furthermore, the integrated ice making and ice storage system further comprises a water collector, the input end of the water collector is communicated with the output end of the flake ice machine, and the output end of the water collector is communicated with the input end of the novel ice making pool.

[0025] Furthermore, the integrated ice-making and ice-storage system also includes a conveyor for moving the ice molds in the new ice-making tank. The conveyor transfers the finished ice molds to the low-temperature end for countercurrent heat exchange with the refrigerant, improving heat exchange efficiency and shortening ice-making time. This effectively addresses operational issues such as low automation, short service life, long ice-making times, low heat exchange efficiency, large floor space requirements, and high ice storage costs.

[0026] Preferably, the conveyor is a plastic chain conveyor.

[0027] Furthermore, a stirrer is provided in the refrigerant storage tank, and a stirring motor is connected to the stirrer.

[0028] Furthermore, the ice quality detectors are located on both sides of the novel ice-making pool, and the ultrasonic transmitters are located on both sides of the ice mold outlet of the novel ice-making pool.

[0029] The present invention provides an integrated ice making and ice storage method based on the cascade utilization of LNG cold energy, comprising the following steps:

[0030] LNG from the LNG storage tank enters the first heat exchanger to exchange heat with the refrigerant. After vaporization and temperature increase, it is further heated by the third heat exchanger. The pressure is then regulated by the pressure regulating valve and then enters the meter for regulation before entering the natural gas pipeline network. The first regulating valve installed between the LNG storage tank and the first heat exchanger regulates the flow of the inflowing LNG and can be used for emergency shutoff.

[0031] The low-temperature primary refrigerant coming out of the shell side of the first heat exchanger enters the second heat exchanger to exchange heat with the secondary refrigerant. The temperature of the low-temperature primary refrigerant increases and circulates into the shell side of the first heat exchanger. The secondary refrigerant cools down and enters the flake ice machine. The low-temperature water coming out of the water adder enters the empty ice mold. The low-temperature secondary refrigerant enters the new ice-making pool through the water collector to cool the low-temperature water in the ice mold. The low-temperature water temperature decreases to form ice cubes. The temperature of the low-temperature secondary refrigerant increases and enters the refrigerant storage tank through the water distributor. The calcium chloride solution is stirred by the stirrer in the refrigerant storage tank until the concentration of the calcium chloride solution is uniform. Then it enters the second heat exchanger tube side to exchange heat with the primary refrigerant, and the cycle is repeated.

[0032] Add low-temperature water to the empty ice mold, and the low-temperature secondary refrigerant enters the new ice-making pool to cool the low-temperature water in the ice mold. The low-temperature water temperature drops to form ice cubes. The low-temperature secondary refrigerant temperature rises and enters the refrigerant storage tank. The salt solution is stirred in the refrigerant storage tank until the concentration of the salt solution is uniform. Then it enters the second heat exchanger tube to exchange heat with the primary refrigerant, and the cycle is repeated.

[0033] The flake ice produced by the flake ice machine directly enters the ice mold of the new ice making pool and mixes with low-temperature water. The flake ice mixes with the low-temperature water in the ice mold as ice crystals, accelerating the formation of ice cubes.

[0034] When the ice cubes in the ice mold are made and the finished ice cubes need to be shipped, the data signal output by the ice cube quality detector is converted into an electrical signal and transmitted to the ultrasonic transmitter. The ultrasonic transmitter excites surface elastic waves with a frequency range of 20-40kHz and a power of 500W, and applies continuous vibration to make the ice mold containing ice cubes de-ice in the new ice-making pool. At the same time, the temperature detector located in the new ice-making pool implements synchronous detection. When the temperature gradient inside the new ice-making pool reaches a stable state, continuous ice making and de-ice begins. The ice cubes and the ice mold are separated by the action of the ultrasonic transmitter, and the separated ice cubes are transported out. At the same time, the demolded ice mold enters a new round of ice-making process.

[0035] Furthermore, the cold energy recovery system also includes a third heat exchanger and a fourth heat exchanger. After the LNG exchanges heat with the first-level refrigerant, it enters the third heat exchanger for reheating. The shell side of the third heat exchanger and the tube side of the fourth heat exchanger both use the third-level refrigerant. The cold water in the shell side of the fourth heat exchanger exchanges heat with the third-level refrigerant in the tube side. The low-temperature water after heat exchange enters the ice mold of the new ice-making pool through the water adder to produce ice blocks.

[0036] Furthermore, the mold lining is made of high-density polyethylene (elastic modulus ≥ 1GPa) to avoid micro-cracks on the surface of the ice cubes.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention uses a flake ice machine and a new ice-making pool in series. After the flake ice is produced, it can directly enter the new ice-making pool and mix with supercooled water to accelerate the ice-making process. During the ice-making process, the flake ice acts as ice crystals to reduce the ice-making time and shorten the ice-making cycle.

[0039] 2. The present invention adopts a flake ice machine in series with a new type of ice-making pool. Within the fluctuation range of LNG flow, the stable output of the flake ice machine can be controlled. When it exceeds the normal range, part of the flake ice can be directly removed, such as sold. (When the LNG vaporization amount exceeds the normal range, based on the fast ice-making characteristics of the flake ice machine, the ice-making process will not be affected by the fluctuation of the LNG vaporization amount. Therefore, the LNG exceeding the normal range can be consumed by making flake ice. At this time, the part of the flake ice exceeding the normal range can be directly sold) to ensure the input of the ice-making pool; when it is lower than the normal range, the electric compression method can be used for supplementary cooling to increase the output of the flake ice machine, thereby ensuring the stable input of the ice-making pool and realizing continuous production.

[0040] 3. The present invention can store finished ice in the new ice-making pool during non-shipping periods, achieving the effect of "one pool for two purposes", realizing the ice-making and ice-storage functions of the new ice-making pool, reducing the area occupied by the ice-making pool and reducing costs.

[0041] 4. This invention incorporates an ice quality detector within the ice mold to monitor ice production at all times. This detector, coupled with an ultrasonic transmitter, provides integrated control. When ice production is complete and ready for shipment, a conveyor transfers the finished ice mold to the new ice-making pool for a new round of ice-making, enabling continuous production. The combined control of the ice quality detector and ultrasonic transmitter simplifies ice transfer and de-icing operations, improves the device's automation, and reduces labor consumption.

[0042] 5. When recovering LNG cold energy, the present invention adopts a cascade cold energy utilization method and uses three-stage refrigerant for heat exchange, thereby realizing multi-temperature cold energy utilization and improving cold energy utilization efficiency.

[0043] 6. The present invention can be provided with a refrigerant storage tank with an agitator when recovering cold energy. The agitator can be used to timely and effectively control the concentration of the salt solution to be uniform and stable, thereby avoiding the generation of solid precipitation and ensuring the cooling performance of the salt solution.

[0044] 7. The novel ice making pool structure of the present invention can be lined with high-density polyethylene and supported by 316L stainless steel to form a stable structure, achieve heat insulation and reduce cold energy loss while reducing corrosion from calcium chloride solution and extending service life.

[0045] 8. The present invention sets a conveyor at the bottom of the ice mold. When the ice making is completed and needs to be shipped, the conveyor starts to move the unfinished ice mold from the high-temperature end to the low-temperature end of the new ice-making pool, so that the ice mold and the salt solution form a countercurrent heat exchange, which improves the heat exchange efficiency and shortens the ice making time.

[0046] 9. The devices used in the present invention are all basic facilities produced on the market, which are cheap, simple to produce and process, and easy to maintain and replace. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of a process flow of an integrated ice making and ice storage device and method based on cascaded utilization of LNG cold energy provided by an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of a novel ice making pool and ice making and storage system implemented in the present invention;

[0049] Figure 3 This is a schematic diagram of a flake ice machine according to an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of a parallel ultrasonic transmitter for ice quality detection according to an embodiment of the present invention;

[0051] In the figure: 1-LNG storage tank, 2-LNG pump, 3-first regulating valve, 4-second regulating valve, 5-air-temperature vaporizer, 6-first heat exchanger, 7-third heat exchanger, 8-pressure regulating valve, 9-second heat exchanger, 10-third regulating valve, 11-fourth regulating valve, 12-compressor, 13-fifth regulating valve, 14-flake ice machine, 15-sixth regulating valve, 16-water collector, 17-new ice making pool, 18-water distributor, 19-refrigerant storage tank, 20-seventh regulating valve, 21-eighth regulating valve, 22-fourth heat exchanger, 23-ninth regulating valve, 24-ice mold, 25-conveyor, 26 ice quality detector, 27 ultrasonic transmitter. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention 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 only used to explain the present invention and are not intended to limit the present invention.

[0053] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, upper end, lower end, top, bottom...) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0054] In the present invention, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, "connection" can mean fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two elements, or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0055] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one such feature. Furthermore, the technical solutions of various embodiments may be combined with each other, but only on the basis that they can be implemented by a person of ordinary skill in the art. If the combination of technical solutions contradicts or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this disclosure.

[0056] Example 1

[0057] Taking the daily output of 1,000 tons of ice as an example, each ice block weighs 75 kg, the average size of industrial ice blocks is 90 mm × 40 mm × 20 mm, the ice mold size is 2,000 mm × 1,500 mm × 1,200 mm, and a daily output of 1,000 tons requires 308 ice molds, saving 72,000 kWh of electricity per day, 21.75 tons of standard coal per day, and 56.5 tons of carbon dioxide emissions per day. The overall volume of the device is 22,500 mm × 24,000 mm × 2,000 mm. Compared with traditional ice making, the floor space and equipment costs are saved by 50% and 38% respectively.

[0058] like Figures 1 to 4 As shown, an embodiment of the present invention provides an integrated ice making and ice storage device based on cascade utilization of LNG cold energy, comprising:

[0059] The LNG vaporization system is used to vaporize LNG, releasing the substantial cold energy contained in the LNG. The system includes an LNG storage tank 1, an LNG pump 2, a first regulating valve 3, a second regulating valve 4, an air-temperature vaporizer 5, and a first heat exchanger 6. The input of the first heat exchanger 6 is connected to the output of the LNG storage tank 1. The input of the air-temperature vaporizer 5 is also connected to the output of the LNG storage tank 1, and the air-temperature vaporizer 5 is connected to the first heat exchanger 6. The air-temperature vaporizer 5 assists in vaporization. The LNG pump 2 is located at the output of the LNG storage tank 1. A second regulating valve 4 is located between the first heat exchanger 6 and the LNG storage tank 1, allowing the amount of LNG vaporized from the station to be appropriately adjusted based on the natural gas usage of downstream users. The first regulating valve 3 is located between the LNG storage tank 1 and the air-temperature vaporizer 5. When downstream gas consumption is high and exceeds the cold energy operating load, the first regulating valve 3 is opened, allowing auxiliary vaporization and secondary refrigerant heat exchange vaporization to proceed simultaneously, ensuring an adequate supply of LNG.

[0060] A cold energy recovery system is used to recover the cold energy generated by LNG gasification and supply cold energy to the flake ice-block ice system; the cold energy recovery system includes a second heat exchanger 9, a third heat exchanger 7, a fourth heat exchanger 22, a compressor 12 and a refrigerant storage tank 19; the input end of the refrigerant storage tank 19 is connected to the output end of the water separator 18 of the flake ice-block ice collaborative ice making system, the output end of the refrigerant storage tank 19 is connected to the pipe side input end of the second heat exchanger 9, and a seventh regulating valve 20 is provided between the refrigerant storage tank 19 and the pipe side input end of the second heat exchanger 9; the shell side input end of the second heat exchanger 9 is connected to the shell side input end of the first heat exchanger 6 The shell-side output end is connected; the tube-side input end of the third heat exchanger 7 and the tube-side output end of the first heat exchanger 6 are both connected to the output end of the air-temperature vaporizer 5; the tube-side input end of the fourth heat exchanger 22 is connected to the shell-side output end of the third heat exchanger 7, and an eighth regulating valve 21 is provided between the fourth heat exchanger 22 and the third heat exchanger 7, and a ninth regulating valve 23 is provided at the shell-side input end of the fourth heat exchanger 22; a third regulating valve 10 is provided on the pipeline between the second heat exchanger 9 and the compressor 12. When the LNG gasification amount is small, the compressor 12 is started for supplementary cooling, and the cooling capacity is preferentially provided to the new ice-making pool to ensure the continuity of ice making.

[0061] An integrated ice-making and ice-storage system, which is used to complete the production of block ice and perform the ice storage function at the same time; the integrated ice-making and ice-storage system includes a water collector 16, a new ice-making pool 17, an ice mold 24, and a conveyor 25; the input end of the water collector 16 is connected to the output end of the shell side of the second heat exchanger 9 (the secondary refrigerant coming out of the shell side of the second heat exchanger 9 is not directly mixed with the water in the water collector 16, but enters the new ice-making pool 17 to exchange heat with the ice mold 24, and has no contact with the water in the water collector 16, and the two do not use the same pipe); the input end of the new ice-making pool 17 is connected to the output end of the water collector 16; the ice mold 24 is used to be arranged inside the new ice-making pool 17; the conveyor 25 is located in the new ice-making pool 17 and below the ice mold 24.

[0062] The flake ice-block ice collaborative ice-making system is used to speed up the production of ice cubes and at the same time regulate the fluctuation of LNG gas volume; the flake ice-block ice collaborative ice-making system includes a flake ice machine 14 and a water separator 18; the input end of the flake ice machine 14 is connected to the pipe-side output end of the second heat exchanger 9, and a fourth regulating valve 11 is provided between the flake ice machine 14 and the second heat exchanger 9, the compressor 12 is arranged in parallel with the flake ice machine 14, and the output end of the compressor 12 can be communicated with the new ice-making pool 17; the input end of the water collector 16 is connected to the output end of the flake ice machine 14; the input end of the water separator 18 is connected to the output end of the new ice-making pool 17, and the output end of the water separator 18 is connected to the output end of the refrigerant storage tank 19.

[0063] Conveyor 25 adopts plastic chain conveyor.

[0064] The integrated ice making and ice storage method based on the cascaded utilization of LNG cold energy in this embodiment specifically includes the following steps:

[0065] LNG from LNG storage tank 1 passes through LNG pump 2 and second regulating valve 4 into first heat exchanger 6 for heat exchange with refrigerant. After being vaporized and heated in air-temperature vaporizer 5, it is further heated by third heat exchanger 7. Pressure is then regulated by pressure regulating valve 8 and regulated by a meter before entering the natural gas pipeline network. Second regulating valve 4, located between LNG storage tank 1 and first heat exchanger 6, regulates the flow of incoming LNG and performs emergency shutoff. The metering system and ball-issuing system are used to set up the flow process of NG gas entering the downstream user pipeline network. The metering system's primary function is to achieve flow settlement between suppliers and demanders, followed by real-time detection of flow fluctuations and composition changes in the pipeline fluid. The ball-issuing system's primary function is to remove scale deposits in the pipeline, reduce transportation resistance, and intelligently detect and identify pipeline corrosion defects and geometric deformations. Secondly, it isolates the media by isolating different oil products by emitting isolation balls to prevent oil mixing.

[0066] The low-temperature primary refrigerant coming out of the shell side of the first heat exchanger 6 enters the second heat exchanger 9 to exchange heat with the secondary refrigerant. The temperature of the low-temperature primary refrigerant increases and circulates into the shell side of the first heat exchanger 6. The secondary refrigerant cools down and passes through the fourth regulating valve 11 to enter the flake ice machine 14 to produce flake ice. Low-temperature water is added to the empty ice mold 24, for example, by a water adder (the shell side output end of the fourth heat exchanger 22 is connected to the water adder). The low-temperature secondary refrigerant flows out of the flake ice machine 14 and enters the new ice-making pool 17 through the water collector 16 to cool the low-temperature water in the ice mold 24. The temperature of the low-temperature water decreases to form ice cubes. The temperature of the low-temperature secondary refrigerant increases and passes through the water separator 18 to enter the refrigerant storage tank 19. The calcium chloride solution (other salt solutions can also be used) is stirred by the stirrer in the refrigerant storage tank 19 until the concentration of the calcium chloride solution is uniform. Then it enters the pipe side of the second heat exchanger 9 to exchange heat with the primary refrigerant, and the cycle is repeated.

[0067] The flake ice produced by the flake ice machine 14 enters the ice mold 24 of the new ice-making pool 17, where it mixes with the low-temperature water from the water feeder. The LNG exchanges heat with the primary refrigerant before entering the third heat exchanger 7 for reheating. Both the shell side of the third heat exchanger 7 and the tube side of the fourth heat exchanger 22 use tertiary refrigerant. The cold water in the shell side of the fourth heat exchanger 22 exchanges heat with the tertiary refrigerant in the tube side. The low-temperature water after heat exchange enters the ice mold 24 of the new ice-making pool 17 through the water feeder to produce nugget ice. This simultaneously produces and stores ice. That is, finished ice is stored in the new ice-making pool during non-shipping periods, achieving a dual purpose. This allows the new ice-making pool to fulfill its ice-making and storage functions, reducing floor space and effectively responding to fluctuating ice production demands.

[0068] Example 2

[0069] This embodiment provides an integrated ice-making and ice-storage device based on the cascaded utilization of LNG cold energy. The device comprises four systems: an LNG vaporization system, a cold energy recovery system, a flake ice and block ice collaborative ice-making system, and an integrated ice-making and ice-storage system. The LNG vaporization system comprises an LNG storage tank 1, an LNG pump 2, a first regulating valve 3, a second regulating valve 4, an air-temperature vaporizer 5, and a first heat exchanger 6. The cold energy recovery system comprises a second heat exchanger 9, a third heat exchanger 7, a fourth heat exchanger 22, a compressor 12, and a refrigerant storage tank 19. The flake ice and block ice collaborative ice-making system comprises a flake ice machine 14 and a water distributor 18. The integrated ice-making and ice-storage system comprises a water collector 16, a new ice-making pool 17, an ice mold 24, a conveyor 25, an ice quality detector 26, and an ultrasonic transmitter 27.

[0070] This example provides an integrated ice-making and ice-storage device based on the cascaded utilization of LNG cold energy. The focus is on the specific implementation of a flake ice and novel ice-making tank tandem ice-making system. This system directly supplies cooling to the flake ice machine 14 via a secondary refrigerant, achieving efficient flake ice production. It also works in conjunction with the novel ice-making tank to ensure stable operation under varying LNG flow conditions.

[0071] The flake ice machine 14 receives the low-temperature secondary refrigerant (calcium chloride solution) from the second heat exchanger 9 via the fourth regulating valve 11, using the cold energy to rapidly produce flake ice. The flake ice produced by the flake ice machine 14 is transported through the water collector 16 to the ice mold 24 of the new ice-making pool 17, where it is mixed with supercooled water as ice crystals, accelerating the formation of block ice. The new ice-making pool 17 is equipped with an ice mold 24, and a conveyor 25 is installed at the bottom of the ice mold to move the ice mold 24 and conduct countercurrent heat exchange. Low-temperature water from the fourth heat exchanger 22 is supplied via a water feeder. After mixing with the flake ice, the flake ice is used as ice crystals for the ice blocks in the ice mold 24 to produce block ice. This has the advantages of accelerating heat transfer and shortening the ice-making cycle, reducing a 12-hour ice-making cycle to 6-8 hours. The resulting block ice is of higher quality, saving cooling loss and improving system efficiency. The flake ice used as ice crystals improves the quality of the resulting block ice, and after mixing, the ice-making time is accelerated, improving system efficiency.

[0072] When the LNG flow rate is low, compressor 12 starts to replenish cold energy to the new ice-making pool 17. The second heat exchanger 9 maintains the cold energy supply to the flake ice machine 14 and the new ice-making pool 17, ensuring continuous ice making. When the LNG flow rate is high, some flake ice is directly sold through the bypass, and the remaining flake ice enters the ice mold 24, ensuring a stable load on the ice-making pool.

[0073] The ice quality detector 26 is used to detect the ice in the ice mold 24. The ice quality detector 26 is connected to the ultrasonic transmitter 27. The ice quality detector 26 is located on both sides of the novel ice making pool 17, and the ultrasonic transmitter 27 is located on both sides of the ice mold outlet in the novel ice making pool 17.

[0074] When the ice cubes in the ice mold 24 are made and the finished ice cubes need to be shipped, the ice cube quality detector 26 outputs a data signal that is converted into an electrical signal and transmitted to the ultrasonic transmitter 27. The ultrasonic transmitter 27 excites surface elastic waves with a frequency range of 20-40kHz and applies continuous vibration to cause the ice mold 24 containing ice cubes to be de-iced in the new ice-making pool 17. At the same time, the temperature detector located in the new ice-making pool 17 implements synchronous temperature detection. When the temperature gradient inside the new ice-making pool 17 reaches a stable state, continuous ice making and de-icing begins. The ice cubes and the ice mold 24 are separated by the ultrasonic transmitter 27. The separated ice cubes are transported to the cold chain transport vehicle by the conveyor 25 located at the bottom of the new ice-making pool 17. At the same time, the ice mold 24 is transported to the new ice-making pool 17 by the ice mold lifter arranged above the new ice-making pool 17 through a pulley for a new round of ice making.

[0075] Example 3

[0076] This embodiment provides an integrated ice-making and ice-storage device based on the cascaded utilization of LNG cold energy, comprising four systems: an LNG vaporization system, a cold energy recovery system, a flake ice and block ice collaborative ice-making system, and an integrated ice-making and ice-storage system. The LNG vaporization system comprises an LNG storage tank 1, an LNG pump 2, a first regulating valve 3, a second regulating valve 4, an air-temperature vaporizer 5, and a first heat exchanger 6; the cold energy recovery system comprises a second heat exchanger 9, a third heat exchanger 7, a fourth heat exchanger 22, a compressor 12, and a refrigerant storage tank 19; the flake ice and block ice collaborative ice-making system comprises a flake ice machine 14 and a water distributor 18; and the integrated ice-making and ice-storage system comprises a water collector 16, a new ice-making pool 17, an ice mold 24, a conveyor 25, an ice quality detector 26, and an ultrasonic transmitter 27.

[0077] The ice quality detector 26 uses multimodal sensing fusion technology, which contains an ultrasonic pulse reflection sensor, an infrared thermal imaging array and a conductivity sensor to determine the production status of ice cubes in the ice mold 24; the ultrasonic pulse reflection sensor is used to confirm whether the ultrasonic generator 27 is working properly, and the infrared thermal imaging array is used to detect the temperature gradient and density of the ice mold 24. The infrared thermal imaging array covers the surface of the ice mold, monitors the temperature field distribution of the ice cubes in real time, and determines the uniformity of the freezing of the ice cubes. When the temperature difference of the detection temperature of the infrared thermal imaging array is less than the preset value, such as ≤0.5℃, it can be said that the ice cubes in the ice mold 24 have been made. When the customer needs ice cubes, the sensors are extracted through a pre-set program. The key parameters of the ice cube (such as temperature gradient, density, conductivity, etc.) are used to construct the ice quality feature vector, and the ice grade is comprehensively determined by the machine learning model (the technology of determining the ice grade based on the ice quality feature vector and the machine learning model can be realized through existing technology. The key parameters are collected by infrared thermal imaging array sensors and conductivity sensors, and then the accuracy and learning of image recognition of the AI ​​large model are used to accurately judge the quality of the ice. For example, the bubble distribution characteristics of the ice cubes in the image can be identified by AI, and the ice cubes can be divided into different grades. The constructed ice feature vector can be understood as a mathematical analysis of the ice parameters in the ice making pool, and the ice quality is evaluated from different dimensions. The temperature mentioned above , density, conductivity and bubble distribution characteristics can all be used to evaluate the quality of ice. The collection of all these evaluation criteria is called the ice quality feature vector. The bubble distribution characteristics of ice are a subset of the ice quality feature vector. The bubble distribution characteristics of ice are the distribution of cavities contained in the ice after it is formed. Data can be collected through an infrared thermal imaging array to form a temperature gradient image on a computer. The temperature gradient image can reflect the cavity distribution of the ice. The AI ​​large model can be used to quickly learn a large number of such temperature gradient images to achieve the purpose of using a machine to determine the quality of ice. The results are transmitted to the central control center through electrical signals, and then a signal is sent to the ultrasonic wave. Generator 27, an ultrasonic generator, excites surface elastic waves with a frequency range of 20-40kHz and a power of 500W. Ice mold 24 is lined with high-density polyethylene (elastic modulus ≥ 1GPa) to prevent microcracks on the ice surface. Continuous vibration is applied to separate the ice in the new ice-making pool 17 from the ice mold 24. After separation, a conveyor 25 at the bottom of the new ice-making pool 17 transports the ice to the ice-discharging station. When there is no shipment demand, finished ice can be stored in the new ice-making pool 17 during non-shipping hours, achieving a "one pool, two uses" effect. This realizes the ice-making and ice-storage functions of the new ice-making pool, reduces the pool's footprint by 50%, and significantly reduces costs.

[0078] In the embodiment of the present invention, an ice quality detector 26 is provided in the ice mold 24, which can monitor the ice making status at any time and can be connected to an ice mold lifter (the ice mold lifter is an existing device, such as the ice mold lifter disclosed in CN119573301A) for joint control. When ice making is completed, the ice mold lifter transfers the completed ice mold, and then another ice mold lifter transfers the empty ice mold to the new ice making pool 17 for adding water to make ice. In this way, the degree of automation of the device is improved, manpower consumption is reduced, and continuous production is achieved.

[0079] The embodiment of the present invention provides an integrated ice making and ice storage device and method based on the cascade utilization of LNG cold energy. When recovering LNG cold energy, a cascade utilization method of cold energy is adopted, and a three-stage refrigerant is used for heat exchange, so as to realize multi-temperature cold energy utilization and improve the cold energy utilization efficiency. The calcium chloride solution buffer tank (refrigerant storage tank) with an agitator can timely and effectively control the concentration of the calcium chloride solution to be uniform and stable, maintain the concentration of the calcium chloride solution to ensure the cooling performance of the calcium chloride solution. The ice making process adopts a flake ice machine connected in series with a new ice making pool. Within the fluctuation range of LNG flow, the stable output of the flake ice machine can be controlled. When it exceeds the normal range, part of the flake ice can be directly sold to ensure the input of the ice making pool. When it is lower than the normal range, an electric compression method can be used for supplementary cooling to increase the output of the flake ice machine. The new ice making pool structure can be made by High-density polyethylene lining and 316L stainless steel support form a stable structure, and achieve heat insulation to reduce cold energy loss while reducing corrosion from calcium chloride solution and extending service life. At the same time, by storing the finished ice in the new ice-making pool during the non-shipping period, it plays a "one pool, two uses" effect, realizing the ice making and ice storage functions of the new ice-making pool, which can reduce the ice pool footprint and reduce costs; the ice quality detector and ultrasonic transmitter are jointly controlled to reduce the difficulty of ice transfer and ice removal operations, improve the degree of automation of the device, and reduce manpower consumption; the conveyor transfers the finished ice mold to the low-temperature end for countercurrent heat exchange with the refrigerant, which improves heat exchange efficiency and shortens ice-making time, effectively solving problems such as low degree of automation, short service life, long ice-making time, low heat exchange efficiency, large footprint, and high ice storage cost during operation.

[0080] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. The contents of this specification should not be understood as limiting the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. An integrated ice making and ice storage device based on cascade utilization of LNG cold energy, characterized in that: include: An LNG gasification system, which is used to gasify LNG and release the cold energy contained in LNG, includes an LNG storage tank, a first heat exchanger, and an air-temperature vaporizer; the input ends of the first heat exchanger and the air-temperature vaporizer are both connected to the output end of the LNG storage tank, and the first heat exchanger and the air-temperature vaporizer are connected; A cold energy recovery system, which is used to recover cold energy generated by LNG vaporization and supply cooling to the flake ice-block ice system. The cold energy recovery system includes a refrigerant tank and a second heat exchanger. The input end of the refrigerant tank is connected to the output end of the integrated ice making and storage system. The output end of the refrigerant tank is connected to the tube-side input end of the second heat exchanger. The shell-side input end of the second heat exchanger is connected to the shell-side output end of the first heat exchanger. A flake ice-block ice collaborative ice-making system is used to accelerate ice production and regulate LNG gas volume fluctuations. The flake ice-block ice collaborative ice-making system includes a flake ice machine, the input end of which is connected to the output end of the second heat exchanger tube to supply cooling to the flake ice machine, and the flake ice machine is used to produce flake ice. An integrated ice-making and ice-storage system is provided, which is used to produce ice blocks and simultaneously store ice. The integrated ice-making and ice-storage system includes a new ice-making pool, an ice mold, a block quality detector, and an ultrasonic transmitter. The ice mold is arranged inside the new ice-making pool, and low-temperature water can flow into the ice mold. The input end of the new ice-making pool is connected to the output end of the flake ice machine so that the flake ice produced by the flake ice machine can combine with the low-temperature water in the ice mold to accelerate ice formation. The ice quality detector is used to detect ice blocks in the ice mold. The ice quality detector is connected to the ultrasonic transmitter, and the ultrasonic transmitter is used to separate the ice blocks from the ice mold.

2. The integrated ice making and ice storage device based on cascade utilization of LNG cold energy according to claim 1 is characterized in that: The cold energy recovery system also includes a third heat exchanger and a fourth heat exchanger; the tube side input end of the third heat exchanger is connected to the tube side output end of the first heat exchanger; the tube side input end of the fourth heat exchanger is connected to the shell side output end of the third heat exchanger.

3. The integrated ice making and ice storage device based on cascade utilization of LNG cold energy according to claim 2 is characterized in that: The cold energy recovery system further comprises a compressor, the input end of the compressor is connected to the pipe side output end of the second heat exchanger, and the output end of the compressor is communicated with the novel ice making pool.

4. The integrated ice making and ice storage device based on cascade utilization of LNG cold energy according to claim 2 is characterized in that: The flake ice and block ice collaborative ice making system further comprises a water separator, the input end of the water separator is communicated with the output end of the novel ice making pool, and the output end of the water separator is connected to the output end of the refrigerant storage tank.

5. The integrated ice making and ice storage device based on cascade utilization of LNG cold energy according to claim 2 is characterized in that: Low-temperature water is introduced into the ice mold through a water adder, and the input end of the water adder is communicated with the output end of the shell side of the fourth heat exchanger.

6. The integrated ice making and ice storage device based on cascade utilization of LNG cold energy according to claim 2 is characterized in that: The integrated ice making and ice storage system further comprises a water collector, the input end of the water collector is communicated with the output end of the flake ice machine, and the output end of the water collector is communicated with the input end of the novel ice making pool.

7. The integrated ice making and ice storage device based on cascade utilization of LNG cold energy according to claim 1 is characterized in that: The integrated ice making and ice storage system further includes a conveyor, which is used to move the ice molds.

8. The integrated ice making and ice storage device based on cascade utilization of LNG cold energy according to claims 1-7 is characterized in that: A stirrer is provided in the refrigerant storage tank.

9. An integrated ice making and ice storage method based on cascade utilization of LNG cold energy, characterized in that: Using the device according to any one of claims 1 to 9, the method comprises the following steps: LNG from the LNG storage tank enters the first heat exchanger to exchange heat with the refrigerant; The low-temperature primary refrigerant coming out of the shell side of the first heat exchanger enters the second heat exchanger to exchange heat with the secondary refrigerant. The low-temperature primary refrigerant is heated up and circulates into the shell side of the first heat exchanger. The secondary refrigerant is cooled down and enters the flake ice machine. Add low-temperature water to the empty ice mold, and the low-temperature secondary refrigerant enters the new ice-making pool to cool the low-temperature water in the ice mold. The low-temperature water temperature drops to form ice cubes. The low-temperature secondary refrigerant temperature rises and enters the refrigerant storage tank. The salt solution is stirred in the refrigerant storage tank until the concentration of the salt solution is uniform. Then it enters the second heat exchanger tube to exchange heat with the primary refrigerant, and the cycle is repeated. The flake ice produced by the flake ice machine directly enters the ice mold of the new ice making pool and mixes with low-temperature water. The flake ice mixes with the low-temperature water in the ice mold as ice crystals, accelerating the formation of ice cubes. When the ice cubes in the ice mold are made and the finished ice cubes need to be shipped, the data signal output by the ice cube quality detector is converted into an electrical signal and transmitted to the ultrasonic transmitter. The ultrasonic transmitter excites surface elastic waves and applies continuous vibration to make the ice mold containing ice cubes de-ice in the new ice-making pool. At the same time, the temperature detector located in the new ice-making pool implements synchronous detection. When the temperature gradient inside the new ice-making pool reaches a stable state, continuous ice making and de-ice begins. The ice cubes and the ice mold are separated by the action of the ultrasonic transmitter, and the separated ice cubes are transported out. At the same time, the demolded ice mold enters a new round of ice-making process.

10. The integrated ice making and ice storage method based on cascaded utilization of LNG cold energy according to claim 9, characterized in that: The cold energy recovery system also includes a third heat exchanger and a fourth heat exchanger. After the LNG exchanges heat with the first-level refrigerant, it enters the third heat exchanger for reheating. The shell side of the third heat exchanger and the tube side of the fourth heat exchanger both use the third-level refrigerant. The cold water in the shell side of the fourth heat exchanger exchanges heat with the third-level refrigerant in the tube side. The low-temperature water after heat exchange enters the ice mold of the new ice-making pool through the water adder to produce ice blocks.

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