Intermittent MVR (mechanical vapor recompression) system and method for boiling beer

Abstract

The invention discloses an intermittent MVR (mechanical vapor recompression) system and method for beer boiling, relates to the technical field of beer brewing, and aims to solve the problems of matching contradiction between an MVR process and beer production and risks of product safety and equipment reliability. A water outlet of the hot water storage tank is communicated with a flash circulating pump, an output end of the flash circulating pump is communicated with a flash tank, an output end of the flash tank is communicated with a compressor, an output end of the compressor is communicated with a heating jacket of a boiling pot, and a water outlet of the heating jacket is communicated with a water return port of the hot water storage tank; the hot water storage tank is further communicated with an exhaust heat exchanger, and an exhaust port of the boiling pot is communicated with the exhaust heat exchanger.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of beer brewing, in particular to an intermittent MVR system and method for beer boiling. BACKGROUND

[0002] In beer production, wort boiling is a key process that determines the flavor and stability of beer, and is also the process with the highest energy consumption, accounting for about 40-50% of the entire brewing process. The traditional process relies on gas, biomass or electric boilers to generate steam, which is indirectly heated through the jacket of the boiling kettle, resulting in low energy utilization efficiency and high carbon emissions.

[0003] Mechanical vapor recompression (MVR) technology is a highly efficient evaporation technology that uses a compressor to work on the secondary steam to increase its enthalpy as a heat source for reuse, theoretically greatly reducing the energy consumption of the evaporation process. However, directly applying traditional MVR to the beer boiling process faces two inherent problems:

[0004] 1. Process compatibility contradiction. Beer brewing is a strictly batch and intermittent production process, with a boiling cycle of about 1-2 hours for each boiling kettle and a batch interval of several hours to several days. To achieve optimal energy efficiency and stable operation, traditional MVR systems are usually designed for continuous operation mode, making it difficult to adapt to the frequent start-stop and severe load fluctuations of intermittent operation.

[0005] 2. Product safety and equipment reliability risks. The secondary steam generated by the boiling kettle contains a large amount of volatile substances such as dimethyl sulfide (DMS), hop volatiles and other flavor substances. If this secondary steam is directly compressed and reused for heating, these substances will continuously circulate and accumulate in the system, and penetrate or entrain through the heating wall, seriously contaminating the wort of subsequent batches and damaging product quality. At the same time, the wet steam containing organic matter is also prone to fouling and corrosion of the steam compressor, causing equipment failure.

[0006] Although there are cases of MVR used for evaporation and concentration in food, chemical and other industries in the prior art, the core contradictions of adapting to batch brewing process and absolutely ensuring product flavor cross-contamination risk have not been solved from the system principle. Therefore, the industry urgently needs a high-efficiency steam supply solution specially designed for beer boiling process, which can perfectly match batch production and be absolutely safe. SUMMARY

[0007] This invention aims to resolve the contradiction between MVR (Multi-Volume Recycling) technology and beer production, as well as the risks to product safety and equipment reliability. It proposes an intermittent MVR system for beer boiling, comprising a high-temperature hot water storage tank. The outlet of the hot water storage tank is connected to a flash circulation pump, the output of which is connected to a flash tank. The output of the flash tank is connected to a compressor, the output of which is connected to the heating jacket of a boiling kettle. The outlet of the heating jacket is connected to the return outlet of the hot water storage tank. An exhaust heat exchanger is also connected to the hot water storage tank, and the exhaust port of the boiling kettle is connected to the exhaust heat exchanger.

[0008] A further provision of the present invention is that the outlet of the flash tank is connected to the hot water storage tank.

[0009] A further provision of the present invention is that a vapor-liquid separator is provided between the flash tank and the compressor.

[0010] A further provision of the present invention is that the output end of the compressor is connected to a steam distribution unit, the steam distribution unit includes a plurality of output ports, and each of the output ports is connected to a heating jacket.

[0011] A further provision of the present invention includes: a circulating pump is installed in the pipeline between the heating storage tank and the exhaust heat exchanger; a temperature sensor and a liquid level sensor are installed on the hot water storage tank; a pressure sensor and a steam flow meter are installed downstream of the compressor; and a control module is also included, wherein the circulating pump, the temperature sensor, the liquid level sensor, the flash circulating pump, the drive motor of the compressor, the pressure sensor, the steam flow meter, and the control system of the boiling pot are all electrically connected to the control module to receive the parameters detected by it and to output control signals to it.

[0012] A further feature of the present invention is that an auxiliary heat pump is connected to the hot water storage tank, and a second circulation pump is installed between the hot water storage tank and the auxiliary heat pump, and the second circulation pump is also electrically connected to the control module.

[0013] This invention also proposes an intermittent MVR method for beer boiling, employing the system described in any one of claims 1-6, characterized by comprising the following steps: S1: Heat source storage and system standby. Before the start of the brewing production cycle, the clean water in the hot water storage tank is heated and maintained at a target temperature of 75-95°C by the auxiliary heat pump and / or the waste heat recovery of the boiling pot exhaust, so as to accumulate sufficient heat. S2: Batch start response. When the system issues a batch production start command for a certain boiling pot, the batch control module receives the signal and activates the steam supply line corresponding to the boiling pot. S3: Indirect steam production; S4: Steam pressurization and supply; S5: System standby. When the boiling process of this batch is completed, after the control module receives the end signal, it controls the steam distribution unit to cut off the steam supply to the boiling pot, and then stops the compressor and the flash circulation pump in sequence. The supply line stops running, the system stops, and enters a low-energy standby state. S6: Multi-batch scheduling and load adjustment. When the production batches of multiple boiling pots are staggered or overlapped in time, the control module dynamically adjusts the operating frequency of the compressor and the liquid inlet of the flash tank according to the start-up and shutdown sequence of each boiling pot and the actual steam demand, so as to achieve flexible scheduling and load matching of multiple steam supplies.

[0014] A further configuration of the present invention is that step S3 specifically includes the following steps: S3-1: The hot water in the hot water storage tank, driven by the second circulation pump, can circulate between the heating heat pump and the hot water storage tank, and thus be continuously heated to compensate for the heat loss in the hot water storage tank; at the same time, driven by the first circulation pump, the hot water can also circulate between the exhaust heat exchanger and the hot water storage tank, and thus the hot air discharged from the boiling pot can also heat it. S3-2: The hot water in the hot water storage tank is quantitatively transported to the flash tank through the flash circulation pump, and the hot water undergoes flash evaporation in the flash tank to generate low-pressure clean steam.

[0015] A further configuration of the present invention is that step S4 specifically includes the following steps: S4-1: The low-pressure steam in the flash tank is separated by the vapor-liquid separator and then drawn into the compressor for compression to compress the steam to 0.4MPa (G) 152℃; S4-2: The compressed high-temperature and high-pressure clean steam is sent into the steam distribution unit, which then delivers it to the heating jacket of the designated boiling pot.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. This invention utilizes a flash evaporation and compression process to completely isolate the produced steam from the contamination of secondary cooking. Heat transfer is achieved solely through an exhaust heat exchanger and a heating heat pump, avoiding direct contact between the material and the steam. This fundamentally eliminates the risk of cross-contamination. The compressor always processes clean steam, ensuring reliable operation and greatly extending the system's service life.

[0018] 2. Through batch response control of the control module, the system no longer operates continuously, but can start and stop in accordance with the start and stop of batch production, accurately responding to the independent needs of each boiling pot and achieving seamless cycle adaptation. Attached Figure Description

[0019] Figure 1 A schematic diagram of the structure of the present invention is shown.

[0020] Figure 2 A schematic diagram of the structure of the present invention after connecting the control module is shown.

[0021] Figure 3 A flowchart of the present invention is shown.

[0022] Reference numerals in the attached diagram: 1. Hot water storage tank; 11. Exhaust heat exchanger; 111. Circulation pump one; 12. Auxiliary heat pump; 121. Circulation pump two; 13. Temperature sensor; 14. Liquid level sensor; 2. Flash circulation pump; 3. Flash tank; 4. Compressor; 41. Pressure sensor; 42. Steam flow meter; 5. Boiling pot; 51. Heating jacket; 6. Vapor-liquid separator; 7. Steam distribution unit; 8. Control module. Detailed Implementation

[0023] Those skilled in the art can refer to the content of this document and appropriately improve the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention.

[0024] Example 1

[0025] This invention proposes an intermittent MVP system for beer boiling, comprising a high-temperature hot water storage tank 1, wherein the water in the hot water storage tank 1 is selected as deionized softened water or purified water. The hot water storage tank 1 is provided with a replenishment port for replenishing water, and a power control valve is installed on the replenishment port; that is, the power control valve can be any one of a pneumatic valve, an electric valve, or a solenoid valve capable of automated control.

[0026] The outlet of the hot water storage tank 1 is connected to the flash circulation pump 2, and the output port of the flash circulation pump 2 is connected to the flash tank 3, so as to pump the water in the hot water storage tank 1 into the flash tank 3.

[0027] The output end of the flash tank 3 is connected to the compressor 4. The compressor 4 is a variable frequency screw type or centrifugal type, and its speed is adjustable. The output end of the compressor 4 is connected to the heating jacket 51 of the boiling pot 5. That is, the hot water entering the flash tank 3 will be flashed into low-pressure saturated steam under low pressure in the flash tank 3. The low-pressure saturated steam is then compressed by the compressor 4 into high-pressure and high-temperature steam, i.e., 0.3-0.6MPa (G), and then introduced into the heating jacket 51. The high-temperature and high-pressure steam is used to heat and boil the boiling pot 5.

[0028] The outlet of the heating jacket 51 is connected to the return outlet of the hot water storage tank 1. A steam trap is installed at the outlet of the heating jacket 51 to return the condensate from the steam to the hot water storage tank 1 for continued use, thus forming a water circulation system. The hot water storage tank 1 is also connected to an exhaust heat exchanger 11. One branch of the exhaust heat exchanger 11 is connected to the hot water storage tank 1, and a circulation pump 111 is installed on this branch to circulate the water in the hot water storage tank 1 between the exhaust heat exchanger 11 and the hot water storage tank 1. The other branch of the exhaust heat exchanger 11 is connected to the exhaust port of the boiling pot 5, allowing the hot air discharged from the boiling pot 5 to enter the heat exchanger and heat the water in the hot water storage tank 1.

[0029] The outlet of the flash tank 3 is also connected to the hot water storage tank 1, meaning that the liquid water separated in the flash tank 3 will be recycled back into the hot water storage tank 1 for heating and reuse.

[0030] A vapor-liquid separator 6 is also installed between the flash tank 3 and the compressor 4 to remove any entrained droplets and prevent them from entering the compressor 4. This ensures that the vapor entering the compressor 4 is saturated steam with high dryness, thereby protecting the service life of the compressor 4.

[0031] The output end of the compressor 4 is also connected to a steam distribution unit 7. The steam distribution unit 7 includes a gas supply port. The steam distribution unit 7 uses a multi-way valve group. Each output port of the valve group is also equipped with a power control valve. Each branch is connected to a heating jacket 51. That is, each heating jacket 51 corresponds to a boiling pot 5. Several boiling pots 5 are set in parallel, and the exhaust ports of several boiling pots 5 are all connected to the exhaust heat exchanger 11, so that the water outlets of several heating jackets 51 are also connected to the hot water storage tank 1.

[0032] An auxiliary heat pump 12 is also connected to the hot water storage tank 1. The condenser of the auxiliary heat pump 12 is also a heat exchanger. One of its pipes is connected to the hot water storage tank 1, and a circulation pump 2 121 is also installed on its pipes to circulate the clean water in the hot water storage tank 1 between the auxiliary heat pump 12 and the hot water storage tank 1. The other evaporator pipe of the auxiliary heat pump 12 is used to connect to the condensation heat recovery of the brewery refrigeration system or the waste heat recovery heat sink in other production processes to provide auxiliary heating for the clean water in the hot water storage tank 1.

[0033] The hot water storage tank 1 is also equipped with a temperature sensor 13 and a liquid level sensor 14. The temperature sensor 13 is used to detect the temperature of the clean water in the hot water storage tank 1 to ensure that the clean water in the hot water storage tank 1 is maintained at 85°C, while the liquid level sensor 14 can be used to detect the height of the clean water level in the hot water storage tank 1, so that water can be replenished in time when there is a shortage.

[0034] A steam flow meter 42 and a pressure sensor 41 are also installed on the downstream pipeline of compressor 4 to detect the pressure and flow rate of the steam output by compressor 4.

[0035] It should be noted that a control module 8 is also included. The control module 8 is a PLC programmable controller. The drive motors of the first circulating pump 111, the second circulating pump 121, the temperature sensor 13, the liquid level sensor 14, the flash circulating pump 2, the compressor 4, the pressure sensor 41, the steam flow meter 42, the control system of the boiling pot 5, and each power control valve are all electrically connected to the control module 8 to output corresponding signals to the control module 8, and to receive control signals from the control module 8 based on the corresponding signals and make relevant responses.

[0036] Control logic sequence:

[0037] 1. Heat source preparation stage: Control module 8 detects the water temperature and liquid level in hot water storage tank 1, and sets the water temperature to 85℃ as the standard state. When the water temperature is lower than 85℃, control module 8 controls circulation pump 2 121 to start, and auxiliary heat pump 12 starts to heat the clean water in hot water storage tank 1. When the liquid level is lower than the set height, control module 8 controls the power control valve of the liquid replenishment port to open, and automatically replenishes water to hot water storage tank 1.

[0038] 2. Batch Start-up Phase: After the wort is fed into the boiling pot 5 and the heating process is about to begin, the production control system sends a start signal to the control module 8. The control module 8 then starts the flash circulation pump 2 of the corresponding flash tank 3 to the preset frequency. After a delay of several seconds to confirm that the pressure of the flash tank 3 has stabilized at the set low pressure of 0.06 MPa abs, the compressor 4 is started to the preset frequency. The entire start-up process is completed within 30-60 seconds.

[0039] 3. During the boiling process, the control module 8 dynamically adjusts the operating frequency of the compressor 4 and the operating frequency of the flash circulation pump 2 based on the real-time temperature or steam demand feedback of the boiling pot 5 (i.e., the steam pressure of the heating jacket 51 or the valve opening). This achieves stepless adjustment of steam output and meets the different needs of high load during the heating period and low load during the boiling and heat preservation period.

[0040] 4. Batch End Stage: After boiling is completed, the control system of the boiling pot 5 sends an end signal to the control module 8. The control module 8 executes the signal and immediately cuts off the continued supply of steam to the heating jacket 51 through the power control valve on the steam distribution unit 7. Then, the compressor 4 and the flash circulation pump 2 are stopped in sequence, the supply line stops running, the system shuts down, and enters a low-energy standby state.

[0041] 5. Condensate recovery: The high-temperature condensate (usually >95℃) discharged from each boiling pot 5 is recovered into the paper hot water storage tank 1 by gravity or by a recovery pump.

[0042] Example 2

[0043] An intermittent MVR method for beer boiling, employing the system disclosed in Example 1, includes the following steps:

[0044] S1: Heat source storage and system standby. Before the start of the brewing production cycle, the clean water in the hot water storage tank 1 is heated and maintained at a target temperature of 85°C by the auxiliary heat pump 12 and / or the waste heat recovery from the exhaust of the boiling pot 5, so as to accumulate sufficient heat.

[0045] S2: Batch start response. When the system issues a batch production start command for a certain boiling pot 5, the batch control module 8 receives the signal and activates the steam supply line corresponding to the boiling pot 5.

[0046] S3: Indirect steam production.

[0047] S4: Steam pressurization and supply.

[0048] S5: System standby. When the boiling process of this batch is completed, after the control module 8 receives the end signal, it controls the steam distribution unit 7 to cut off the steam supply to the boiling pot 5, and then stops the compressor 4 and the flash circulation pump 2 in sequence. The supply line stops running, the system stops, and enters a low-energy standby state.

[0049] S6: Multi-batch scheduling and load adjustment. When the production batches of multiple boiling pots 5 are staggered or overlapped in time, the control module 8 dynamically adjusts the operating frequency of the compressor 4 and the liquid inlet of the flash tank 3 according to the start-up and shutdown sequence of each boiling pot 5 and the actual steam demand, so as to achieve flexible scheduling and load matching of multiple steam supplies.

[0050] Step S3 specifically includes the following steps:

[0051] S3-1: The hot water in the hot water storage tank 1, driven by the second circulation pump 121, can circulate within the heating heat pump and the hot water storage tank 1, thereby being continuously heated to compensate for the heat loss in the hot water storage tank 1; at the same time, driven by the first circulation pump 111, the hot water can also circulate within the exhaust heat exchanger 11 and the hot water storage tank 1, thereby heating the hot air discharged from the boiling pot 5.

[0052] S3-2: The hot water in the hot water storage tank 1 is quantitatively transported to the flash tank 3 through the flash circulation pump 2. The hot water undergoes flash evaporation in the flash tank 3, thereby generating low-pressure clean steam.

[0053] Step S4 specifically includes the following steps:

[0054] S4-1: The low-pressure steam in the flash tank 3 is separated by the vapor-liquid separator 6 and then drawn into the compressor 4 for compression to compress the steam to 0.4MPa (G) 152℃.

[0055] S4-2: The compressed high-temperature and high-pressure clean steam is sent into the steam distribution unit 7, and the steam distribution unit 7 delivers it to the heating jacket 51 of the designated boiling pot 5.

[0056] In summary, this invention utilizes a flash evaporation and compression path to completely isolate the produced steam from contaminants from secondary cooking. Heat transfer is achieved solely through the exhaust heat exchanger 11 and the heating heat pump, avoiding direct contact between the material and the steam. This fundamentally eliminates the risk of cross-contamination. The compressor 4 consistently processes clean steam, ensuring reliable operation and significantly extending the system's lifespan. Through batch-response control by the control module 8, the system no longer operates continuously but can start and stop in sync with the start and stop of batch production, precisely responding to the independent needs of each boiling pot 5 and achieving seamless cycle adaptation.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be within the scope of protection of the present invention.

Claims

1. An intermittent MVR system for beer boiling, characterized in that, The system includes a high-temperature hot water storage tank (1), the outlet of which is connected to a flash circulation pump (2), the output end of which is connected to a flash tank (3), the output end of which is connected to a compressor (4), the output end of which is connected to a heating jacket (51) of a boiling pot (5), the outlet of which is connected to the return outlet of the hot water storage tank (1); the hot water storage tank (1) is also connected to an exhaust heat exchanger (11), and the exhaust port of the boiling pot (5) is connected to the exhaust heat exchanger (11).

2. The intermittent MVR system for beer boiling according to claim 1, characterized in that, The outlet of the flash tank (3) is connected to the hot water storage tank (1).

3. The intermittent MVR system for beer boiling according to claim 1, characterized in that, A vapor-liquid separator (6) is also provided between the flash tank (3) and the compressor (4).

4. The intermittent MVR system for beer boiling according to claim 1, characterized in that, The output end of the compressor (4) is connected to a steam distribution unit (7), which includes several output ports, and each output port is connected to a heating jacket (51).

5. The intermittent MVR system for beer boiling according to claim 1, characterized in that, A circulation pump (111) is installed on the pipeline between the heating tank and the exhaust heat exchanger (11). A temperature sensor (13) and a liquid level sensor (14) are installed on the hot water tank (1). A pressure sensor (41) and a steam flow meter (42) are installed downstream of the compressor (4). A control module (8) is also included. The circulation pump (111), the temperature sensor (13), the liquid level sensor (14), the flash circulation pump (2), the drive motor of the compressor (4), the pressure sensor (41), the steam flow meter (42), and the control system of the boiling pot (5) are all electrically connected to the control module (8) to receive the parameters detected by it and output control signals to it.

6. The intermittent MVR system for beer boiling according to claim 5, characterized in that, An auxiliary heat pump (12) is also connected to the hot water storage tank (1). A second circulation pump (121) is also installed between the hot water storage tank (1) and the auxiliary heat pump (12). The second circulation pump (121) is also electrically connected to the control module (8).

7. An intermittent MVR method for beer boiling, employing the system as described in any one of claims 1-6, characterized in that, Specifically, the following steps are included: S1: Heat source reserve and system standby. Before the start of the brewing production cycle, the clean water in the hot water storage tank (1) is heated and maintained at a target temperature of 75-95°C by the waste heat recovery of the exhaust gas from the auxiliary heat pump (12) and / or the boiling pot (5) to accumulate sufficient heat. S2: Batch start response. When the system issues a batch production start command for a certain boiling pot (5), the batch control module (8) receives the signal and activates the steam supply line corresponding to the boiling pot (5). S3: Indirect steam production; S4: Steam pressurization and supply; S5: System standby. When the boiling process of this batch is completed, the control module (8) receives the end signal and controls the steam distribution unit (7) to cut off the steam supply to the boiling pot (5). Then, the compressor (4) and the flash circulation pump (2) are stopped in sequence. The supply line stops running, the system stops, and enters a low-energy standby state. S6: Multi-batch scheduling and load adjustment. When the production batches of multiple boiling pots (5) are staggered or overlapped in time, the control module (8) dynamically adjusts the operating frequency of the compressor (4) and the liquid inlet of the flash tank (3) according to the start-up and shutdown sequence of each boiling pot (5) and the real-time steam demand, so as to realize flexible scheduling and load matching of multiple steam supplies.

8. The intermittent MVR method for beer boiling according to claim 7, characterized in that, Step S3 specifically includes the following steps: S3-1: The hot water in the hot water storage tank (1) can circulate between the heating heat pump and the hot water storage tank (1) under the drive of the second circulation pump (121), and thus be continuously heated to compensate for the heat loss in the hot water storage tank (1); at the same time, under the drive of the first circulation pump (111), the hot water can also circulate between the exhaust heat exchanger (11) and the hot water storage tank (1), and thus the hot air discharged from the boiling pot (5) can also heat it; S3-2: The hot water in the hot water storage tank (1) is quantitatively transported to the flash tank (3) through the flash circulation pump (2), and the hot water undergoes flash evaporation in the flash tank (3) to generate low-pressure clean steam.

9. The intermittent MVR method for beer boiling according to claim 7, characterized in that, Step S4 specifically includes the following steps: S4-1: The low-pressure steam in the flash tank (3) is separated by the vapor-liquid separator (6) and then drawn into the compressor (4) for compression to compress the steam to 0.4MPa (G) 152℃; S4-2: The compressed high-temperature and high-pressure clean steam is sent into the steam distribution unit (7), and the steam distribution unit (7) delivers it to the heating jacket (51) of the designated boiling pot (5).

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