Table vinegar double-fermentation waste heat gradient utilization system

Abstract

The invention discloses a vinegar double-fermentation waste heat gradient utilization system which comprises two tank bodies, namely an alcohol fermentation tank and an acetic acid fermentation tank, and further comprises a heat pump circulation module, a heat storage unit, a heat release module and a control module which are arranged between the alcohol fermentation tank and the acetic acid fermentation tank, waste heat recovery is performed on the alcohol fermentation tank through the heat pump circulation module, the heat pump improves low-grade heat and then conveys the heat to the heat storage unit, and the heat storage unit releases the heat into the acetic acid fermentation tank according to needs. According to the vinegar double-fermentation waste heat gradient utilization system, low-grade waste heat (35-40 DEG C) generated by alcohol fermentation is increased to medium-high grade (50-60 DEG C) through the heat pump circulation module, heat transfer efficiency limitation caused by small temperature difference in a traditional process is broken through, and waste heat utilization potential is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of vinegar production, in particular to a cascade utilization system for waste heat from double fermentation of vinegar. Background Art

[0002] Vinegar is an aqueous solution containing 4%-8% acetic acid, supplemented by other organic acids, esters, amino acids and trace sugars, which give it a unique flavor. Among them, acetic acid is produced by the oxidation of ethanol. The fermentation process relies on the action of microorganisms. During the production and processing of vinegar, it will undergo alcohol fermentation: yeast converts the sugar in the raw materials into ethanol, and acetic acid fermentation: acetic acid bacteria oxidize ethanol into acetic acid under aerobic conditions.

[0003] During vinegar production, alcohol fermentation and acetic acid fermentation require separate heating and temperature control. Traditionally, these two processes operate independently, leading to significant energy waste. Specifically, waste heat from alcohol fermentation is not effectively recovered and is instead released to the environment, resulting in wasted thermal energy. Alternatively, attempts to transfer waste heat from alcohol fermentation to the acetic acid fermentation tank via a heat exchanger are underutilized due to the similar temperatures required for both processes.

[0004] In addition, existing technologies lack an efficient heat storage mechanism and cannot achieve the cascade utilization and on-demand supply of waste heat, resulting in acetic acid fermentation still relying on additional energy for supplementary heating, further increasing energy consumption costs.

[0005] Therefore, there is an urgent need for a system that can efficiently recover, store and use the waste heat of alcohol fermentation to solve the technical bottleneck of high energy consumption and low waste heat utilization caused by independent heating of two links in the traditional process. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a vinegar double fermentation waste heat cascade utilization system, the purpose of which is to solve the above problems.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A vinegar dual fermentation waste heat cascade utilization system includes two tanks, one for alcohol fermentation and the other for acetic acid fermentation, and further includes:

[0009] A heat pump circulation module, a heat storage unit, a heat release module and a control module are provided between the alcohol fermentation tank and the acetic acid fermentation tank. The heat pump circulation module is used to recover waste heat from the alcohol fermentation tank. The heat pump elevates low-grade heat and transmits it to the heat storage unit. The heat storage unit releases heat into the acetic acid fermentation tank as needed.

[0010] Preferably, the alcohol fermentation tank and the acetic acid fermentation tank have the same structure, and a jacket is provided inside the tank wall of the alcohol fermentation tank and the acetic acid fermentation tank. Both the alcohol fermentation tank and the acetic acid fermentation tank are externally provided with a liquid pipe connected to the jacket. A circulating fluid flows in the jacket of the alcohol fermentation tank and the corresponding liquid pipe. The circulating fluid is a 30% ethylene glycol aqueous solution. The circulating fluid absorbs excess heat in the alcohol fermentation tank and performs heat recovery.

[0011] Preferably, the heat pump circulation module also includes a circulation pump and a heat pump. The heat pump is connected to the inlet and outlet liquid pipes on one side of the primary circulation pump through the water interface of its evaporator, and the inlet and outlet liquid ends of the other end of the primary circulation pump are connected to the liquid pipe of the alcohol fermentation tank. The primary circulation pump can drive the circulating fluid to circulate between the jacket of the alcohol fermentation tank and the evaporator of the heat pump to absorb the waste heat of alcohol fermentation.

[0012] Preferably, the heat storage unit further comprises an insulation box with a vacuum insulation layer provided in the box wall and a secondary circulation pump, the vacuum insulation layer reduces the heat loss in the insulation box, a phase change material is stored in the insulation box, a stainless steel spiral tube is embedded in the phase change material, an inlet and outlet at one end of the stainless steel spiral tube is connected to an inlet and outlet pipe at one end of the secondary circulation pump, and the inlet and outlet at the other end of the secondary circulation pump is connected to an evaporator pipe of the heat pump, a secondary circulation medium flows in the stainless steel spiral tube, and the secondary circulation pump can drive the heat transfer oil to circulate and transfer heat between the condenser of the heat pump and the heat storage unit;

[0013] The secondary circulation medium is heat transfer oil.

[0014] Preferably, the phase change material is a paraffin / expanded graphite composite material, the composite ratio of paraffin to expanded graphite is 9:1, the phase change temperature is 45-50°, and the phase change material will undergo solid-liquid phase change at 45-50°C to absorb latent heat.

[0015] Preferably, the heat release module further includes a plate heat exchanger and a preheating circulation pump, the hot side inlet and outlet of the plate heat exchanger are connected to the inlet and outlet liquid pipes at the other end of the stainless steel spiral tube, the cold side inlet and outlet of the plate heat exchanger are connected to the inlet and outlet liquid pipes at one end of the preheating circulation pump, the inlet and outlet liquid ends of the other end of the preheating circulation pump are connected to the liquid pipe of the acetic acid fermentation tank, water flows in the pipe between the preheating circulation pump and the acetic acid fermentation tank, and the secondary circulation medium and water can enter the interior of the plate heat exchanger for heat exchange.

[0016] Preferably, the control module is electrically connected to the heat pump, the primary circulation pump, the secondary circulation pump and the preheating circulation pump, and can adjust the switches and operating states of the components.

[0017] Preferably, temperature sensors are installed in the jackets of the two tanks, at the inlet and outlet of the evaporator and condenser of the heat pump, and inside the insulation box corresponding to the heat storage unit. Each temperature sensor is connected to the control module signal, and the temperature of the corresponding components is monitored in real time through each temperature sensor.

[0018] Preferably, sealing structures are provided at the connections between the inlet and outlet at both ends of the stainless steel spiral tube and the insulation box.

[0019] Preferably, a heater is installed in the acetic acid fermentation tank, and the heater is electrically connected to the control module, so that the acetic acid fermentation tank is temporarily supplemented with heat by the heater.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides a cascaded utilization system for waste heat from dual fermentation of vinegar. This system uses a heat pump circulation module to raise the low-grade waste heat (35-40°C) generated by alcohol fermentation to a medium-to-high-grade heat (50-60°C). This overcomes the heat transfer efficiency limitations caused by the small temperature difference in traditional processes and significantly enhances the potential for waste heat utilization.

[0022] The system uses phase change heat storage technology to achieve efficient and stable heat storage, with high heat storage density and low heat loss. Compared with traditional single heat storage methods, the efficiency is increased by more than 40%. It can accurately release preheated heat (30-35°C) to the acetic acid fermentation tank on demand, reducing additional energy consumption.

[0023] The system significantly reduces external energy consumption through waste heat recovery and cascade utilization, thereby reducing carbon emissions and further reducing corporate production costs, which is in line with the development trend of green manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the system flow of the present invention;

[0025] Figure 2 This is a schematic diagram of the overall structure of the tank body of the present invention;

[0026] Figure 3 It is a schematic diagram of the cross-sectional structure of the tank body of the present invention.

[0027] In the figure: 10, tank body; 11, jacket; 20, liquid pipe. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] See also Figure 1 and 2 The embodiment proposed in this application is: a vinegar dual fermentation waste heat cascade utilization system, including two tanks 10, one for alcohol fermentation and the other for acetic acid fermentation, both of which are made of stainless steel. A heat pump circulation module, a heat storage unit, a heat release module and a control module are arranged between the alcohol fermentation tank and the acetic acid fermentation tank. The control module adopts an existing PLC control system, communicates with sensors and actuators through the Modbus protocol, runs a control algorithm (such as PID, fuzzy logic), and recovers waste heat through the heat pump circulation module. The heat generated by alcohol fermentation is transported to the heat pump circulation module. After heat promotion, the heat pump circulation module raises the low-grade waste heat to a temperature suitable for storage and then transports it to the heat storage unit. The heat storage unit stores the high-temperature heat. When the acetic fermentation tank needs to be preheated, the heat stored in the heat storage unit is released to the acetic fermentation tank as needed through heat release to complete the preheating.

[0030] The alcohol fermentation tank has the same structure as the acetic acid fermentation tank. A jacket 11 is provided in the tank wall of the alcohol fermentation tank and the acetic acid fermentation tank, and a liquid pipe 20 connected to the jacket 11 is provided on the outside of the alcohol fermentation tank and the acetic acid fermentation tank. Circulating fluid flows in the jacket 11 of the alcohol fermentation tank and the corresponding liquid pipe 20. The circulating fluid adopts 30% ethylene glycol aqueous solution. The heat pump circulation module includes a primary circulation pump and a heat pump. The heat pump can adopt existing equipment, which includes a corresponding compressor, evaporator and condenser. The heat pump is connected to the inlet and outlet pipes at one end of the primary circulation pump through the water interface of its evaporator. The inlet and outlet of the other end of the primary circulation pump is connected to the liquid pipe 20 of the alcohol fermentation tank, and then connected to the jacket 11 of the alcohol fermentation tank. After the primary circulation pump is started, the ethylene glycol solution is driven to circulate between the jacket 11 of the alcohol fermentation tank and the evaporator of the heat pump to heat the alcohol fermentation process. The waste heat generated in the process is recovered. In this process, alcohol fermentation is carried out in the alcohol fermentation tank, and yeast converts sugar into ethanol and carbon dioxide, releasing heat in the process. The heat released is about 35-40°C. The circulating fluid flowing in the jacket 11 on the outer wall of the alcohol fermentation tank absorbs the heat in the tank and then heats up to 38-40°C. Since the temperature generated by alcohol fermentation (35-40°C) is close to the temperature required for preheating of acetic acid fermentation (30-35°C), the temperature difference is too small during direct heat exchange and the heat transfer efficiency is low. Therefore, a heat pump is required to increase the heat. The heated fluid is transported to the evaporator of the heat pump through a primary circulation pump. In this process, the circulating fluid continuously transports heat to the heat pump, and the evaporator of the heat pump absorbs the heat of the circulating fluid transported by the primary circulation pump. The refrigerant in the heat pump evaporates and absorbs heat. The compressor of the heat pump improves the heat quality by compressing the refrigerant gas.

[0031] Specifically, the circulating fluid releases heat in the evaporator of the heat pump, and the circulating fluid is cooled (for example, from 38°C to 25°C). The refrigerant in the heat pump absorbs heat and evaporates into gas. The low-temperature gaseous refrigerant is compressed by the compressor, and the temperature rises to 80-90°C. At this time, the gaseous refrigerant becomes a high-temperature and high-pressure gas. The high-temperature gaseous refrigerant condenses into liquid in the condenser of the heat pump, releasing heat (the temperature drops to 50-60°C). The heat pump upgrades the low-grade waste heat (35-40°C) to high-grade thermal energy (50-60°C) by consuming a small amount of electrical energy (COP=3-4), and raises the low-temperature heat to a relatively high temperature through the heat pump for subsequent storage.

[0032] The heat storage unit includes an insulation box and a secondary circulation pump. A vacuum insulation layer is provided inside the wall of the insulation box to reduce heat loss in the insulation box. A phase change material is stored in the insulation box. The phase change material is a paraffin / expanded graphite composite material. The composite ratio of paraffin and expanded graphite is 9:1, and the phase change temperature is 45-50°. The material has a large latent heat storage capacity of ≥200kJ / kg. The use of the composite material can improve the thermal conductivity (≥5W / m·K) and prevent phase change leakage. Compared with a single phase change material, the heat storage efficiency is increased by 40%. The specific capacity of the phase change material in the insulation box is designed to be 1.2 times the daily waste heat produced by the alcohol fermentation tank to ensure that it can be fully absorbed. To collect waste heat from alcohol fermentation, a stainless steel spiral tube is embedded in the phase change material. The inlet and outlet of one end of the stainless steel spiral tube is connected to the inlet and outlet pipes of one end of the secondary circulation pump, and the inlet and outlet of the other end of the secondary circulation pump is connected to the evaporator pipe of the heat pump. The inlet and outlet at both ends of the stainless steel spiral tube and the connection between the insulation box are provided with a sealing structure, which can be directly fixed or provided with a leak-proof sealing ring to prevent leakage of the phase change material in the insulation box. Secondary circulation medium circulates in the stainless steel spiral tube, and the secondary circulation medium is heat transfer oil, which serves as the core heat transfer medium connecting the heat pump condenser and the phase change heat storage unit. After the secondary circulation pump is started, the heat transfer oil is driven to circulate between the condenser of the heat pump and the heat storage unit, and heat is transferred through the heat transfer oil.

[0033] If low-grade waste heat is stored directly, the heat is more likely to be lost quickly and it is difficult to supply it stably to subsequent processes. Therefore, phase change materials are used to store heat. When storing heat, high-temperature heat is transferred from the condenser of the heat pump to the heat storage unit through the secondary circulation medium. The heat transfer oil flows through the stainless steel spiral tube in the heat storage unit and exchanges heat with the phase change material in the insulation box. The phase change material will undergo a solid-liquid phase change at 45-50°C, absorbing a large amount of latent heat (about 200kJ / kg). The temperature is maintained constant until it is completely melted. The heat is stored through the box change material so that it can be released when needed later.

[0034] The heat release module includes a plate heat exchanger and a preheating circulation pump. The hot side inlet and outlet of the plate heat exchanger are connected to the inlet and outlet pipes of the other end of the stainless steel spiral tube, the cold side inlet and outlet of the plate heat exchanger are connected to the inlet and outlet pipes of one end of the preheating circulation pump, and the inlet and outlet of the other end of the preheating circulation pump are connected to the liquid pipe 20 of the acetic acid fermentation tank. Water (H2O) flows in the pipe between the preheating circulation pump and the acetic acid fermentation tank and can be passed into the jacket 11 of the acetic acid fermentation tank. When heat needs to be released, the secondary circulation pump is started to extract the heat transfer oil stored in the heat storage unit and discharge it into the interior of the plate heat exchanger from the hot side inlet and outlet of the plate heat exchanger. At this time, the preheating circulation pump is started to extract water and discharge it into the interior of the plate heat exchanger from the cold side inlet and outlet of the plate heat exchanger. The heat transfer oil and water perform heat exchange inside the plate heat exchanger through adjacent flow channels. After the heat exchange is completed, the heated water is transported to the jacket 11 of the acetic acid fermentation tank through the preheating circulation pump;

[0035] When the acetic acid fermentation tank needs to be heated (preheated), the heat storage unit releases heat, and the thermal oil absorbs heat from the heat storage unit. During this process, the phase change material gradually solidifies and releases latent heat. The thermal oil transfers heat to the water in the acetic acid fermentation tank jacket 11 through the plate heat exchanger, heating the acetic acid in the acetic acid fermentation tank. During this process, the temperature of the phase change material drops from about 50°C to about 35°C. The preheated water (35°C) enters the acetic acid fermentation tank jacket 11 to maintain the required temperature (30-35°C) for acetic acid fermentation.

[0036] The control module is electrically connected to the heat pump, the primary circulation pump, the secondary circulation pump and the preheating circulation pump, and controls the switching state and operation state of the heat pump, the primary circulation pump, the secondary circulation pump and the preheating circulation pump through the control module.

[0037] Furthermore, temperature sensors are installed inside the jackets 11 of the two tank bodies 10, at the inlet and outlet of the evaporator and condenser of the heat pump, and inside the insulation box corresponding to the heat storage unit. Each temperature sensor is connected to the control module signal. The temperature of the corresponding components is monitored by each temperature sensor, and the temperature data is transmitted to the control module in real time, so that the control module can control the operation of the heat pump, the primary circulation pump, the secondary circulation pump and the preheating cycle, and store or release heat in time as needed.

[0038] Furthermore, a heater is installed in the acetic acid fermentation tank, which is electrically connected to the control module. The heater adopts an existing electric heating device, such as an immersion heater with an electric heating rod. When the heat storage unit is insufficient in heat, the control module can temporarily start the heater to supplement the heat of the acetic acid in the acetic acid fermentation tank.

[0039] The pipes involved in the above content all adopt existing pipe structures. The specific methods of pipe connection include but are not limited to flange connection, which can maintain sealing and prevent liquid leakage. The pipe structure is a pipe with a vacuum layer to achieve thermal insulation effect and reduce heat loss.

[0040] The primary circulation pump involved in the above content is a variable frequency centrifugal pump, and the secondary circulation pump and preheating circulation pump are high temperature resistant magnetic pumps.

[0041] Each pipeline involved in the above content is equipped with a solenoid valve electrically connected to the control module. The solenoid valve is electrically connected to the control module, and the opening and closing of the solenoid valve are controlled by the control module. When there is no need to transport or discharge liquid, the control module controls the solenoid valve to remain closed. On the contrary, if liquid needs to be transported or discharged, the solenoid valve is controlled to open to facilitate the transportation and discharge of the liquid.

[0042] The present invention improves the utilization effect of waste heat generated during the alcohol fermentation process through step-by-step waste heat utilization, and provides energy utilization efficiency as shown below:

[0043] The waste heat generated by alcohol fermentation obtains low-grade heat → medium- and high-grade heat after temperature increase by the heat pump → medium- and high-grade heat after heat storage stabilization → heat released by cooling on demand → preheating of acetic acid fermentation.

[0044] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0045] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A vinegar dual fermentation waste heat cascade utilization system, comprising two tanks (10), one for alcohol fermentation and the other for acetic acid fermentation, characterized in that: Also includes: A heat pump circulation module, a heat storage unit, a heat release module and a control module are provided between the alcohol fermentation tank and the acetic acid fermentation tank. The heat pump circulation module is used to recover waste heat from the alcohol fermentation tank. The heat pump elevates low-grade heat and transmits it to the heat storage unit. The heat storage unit releases heat into the acetic acid fermentation tank as needed.

2. A vinegar double fermentation waste heat cascade utilization system according to claim 1, characterized in that: The alcohol fermentation tank and the acetic acid fermentation tank have the same structure. A jacket (11) is provided in the tank wall of the alcohol fermentation tank and the acetic acid fermentation tank. A liquid pipe (20) connected to the jacket (11) is externally provided in the alcohol fermentation tank and the acetic acid fermentation tank. A circulating fluid flows in the jacket (11) of the alcohol fermentation tank and in the corresponding liquid pipe (20). The circulating fluid is a 30% ethylene glycol aqueous solution. The circulating fluid absorbs excess heat in the alcohol fermentation tank and performs heat recovery.

3. A vinegar double fermentation waste heat cascade utilization system according to claim 2, characterized in that: The heat pump circulation module also includes a circulation pump and a heat pump. The heat pump is connected to the inlet and outlet liquid pipes on one side of the primary circulation pump through the water channel interface of its evaporator. The inlet and outlet liquid ends of the other end of the primary circulation pump are connected to the liquid pipe (20) of the alcohol fermentation tank. The primary circulation pump can drive the circulating fluid to circulate between the jacket (11) of the alcohol fermentation tank and the evaporator of the heat pump to absorb the waste heat of the alcohol fermentation.

4. A vinegar double fermentation waste heat cascade utilization system according to claim 1, characterized in that: The heat storage unit also includes an insulation box with a vacuum insulation layer in the box wall and a secondary circulation pump. The vacuum insulation layer reduces heat loss in the insulation box. The insulation box contains a phase change material, and the phase change material is embedded with a stainless steel spiral tube. The inlet and outlet of one end of the stainless steel spiral tube are connected to the inlet and outlet pipes of one end of the secondary circulation pump. The inlet and outlet of the other end of the secondary circulation pump are connected to the evaporator pipe of the heat pump. A secondary circulation medium flows in the stainless steel spiral tube. The secondary circulation pump can drive the heat transfer oil to circulate and transfer heat between the condenser of the heat pump and the heat storage unit. The secondary circulation medium is heat transfer oil.

5. A vinegar double fermentation waste heat cascade utilization system according to claim 4, characterized in that: The phase change material is a paraffin wax / expanded graphite composite material, the composite ratio of paraffin wax to expanded graphite is 9:1, the phase change temperature is 45-50°C, and the phase change material will undergo a solid-liquid phase change at 45-50°C to absorb latent heat.

6. A vinegar double fermentation waste heat cascade utilization system according to claim 4, characterized in that: The heat release module also includes a plate heat exchanger and a preheating circulation pump. The hot side inlet and outlet of the plate heat exchanger are connected to the inlet and outlet liquid pipes at the other end of the stainless steel spiral tube. The cold side inlet and outlet of the plate heat exchanger are connected to the inlet and outlet liquid pipes at one end of the preheating circulation pump. The inlet and outlet liquid ends at the other end of the preheating circulation pump are connected to the liquid pipe (20) of the acetic acid fermentation tank. Water flows in the pipe between the preheating circulation pump and the acetic acid fermentation tank. The secondary circulation medium and water can enter the interior of the plate heat exchanger for heat exchange.

7. The vinegar dual fermentation waste heat cascade utilization system according to claim 1, characterized in that: The control module is electrically connected to the heat pump, the primary circulation pump, the secondary circulation pump and the preheating circulation pump, and can adjust the switches and operating states of the components.

8. The vinegar dual fermentation waste heat cascade utilization system according to claim 1, characterized in that: Temperature sensors are installed in the jackets (11) of the two tank bodies (10), at the inlet and outlet of the evaporator and condenser of the heat pump, and inside the insulation box corresponding to the heat storage unit. Each temperature sensor is connected to the control module signal, and the temperature of the corresponding component is monitored in real time through each temperature sensor.

9. The vinegar dual fermentation waste heat cascade utilization system according to claim 1, characterized in that: Sealing structures are provided at the connections between the inlet and outlet at both ends of the stainless steel spiral tube and the insulation box.

10. The vinegar dual fermentation waste heat cascade utilization system according to claim 1, characterized in that: A heater is installed in the acetic acid fermentation tank, and the heater is electrically connected to the control module. The heater is used to temporarily supplement the heat of the acetic acid fermentation tank.

Images