Starch sugar energy-saving evaporation and centralized heating device

Abstract

This invention relates to the fields of light industry, chemical engineering, and biotechnology, specifically to an energy-saving evaporation and centralized heating device for starch sugar. It includes an evaporation section and a heating section. The evaporation section comprises a primary low-pressure evaporator and a secondary low-pressure evaporator, while the heating section includes a water storage tank and a chilled water tank. This energy-saving evaporation and centralized heating device for starch sugar employs low-pressure, high-vacuum evaporation during the evaporation stage, reducing the evaporation temperature and effectively lowering evaporation power and steam consumption. It also avoids the yellowing of the product and burnt taste caused by high-temperature Maillard reactions. Furthermore, the evaporation stage utilizes a zero-water start-up process, effectively shortening start-up time and concentration enhancement time. The invention also utilizes the recovered hot water in a chilled water tank for reuse and storage, which is then used for central air conditioning heating, improving the utilization rate of the chilled water tank. Simultaneously, the low-temperature tap water in the tank is used for heat exchange to cool the product, saving steam consumption.

Description

Technical Field

[0001] This invention relates to the fields of light industry, chemical industry, and biotechnology, and in particular to an energy-saving evaporation and centralized heating device for starch sugar. Background Technology

[0002] In the starch-to-sugar process, the dry solids content of starch after liquefaction, saccharification, and hydrolysis is less than 40%. According to national standards, taking type 55 fructose syrup as an example, the finished product dry solids content needs to be ≥76.5%. This difference in dry solids content necessitates concentration using an evaporator. During the evaporation and concentration of starch sugar using an MVR evaporator, the temperature of the syrup exiting the evaporator is above 85℃. Even after heat exchange at the inlet and outlet, this portion of the syrup still has a temperature above 60℃. At this point, circulating cooling water is needed for cooling. However, since the lowest temperature of the circulating cooling water is only room temperature, it can only lower the syrup temperature to room temperature at most. In summer, especially in cities like Chongqing, where room temperature is usually above 40℃, circulating cooling water can only lower the syrup temperature to around 42℃, which is still too high and easily causes the syrup to discolor and turn yellow. Therefore, chilled water is needed to cool the syrup to below 35℃. This process has several shortcomings: 1. When using MVR for evaporation and concentration, the vacuum level of the evaporator has a significant impact on the power consumption of MVR. Traditional MVR evaporators concentrate at a pressure of 510 mbar, corresponding to an evaporation temperature of over 85°C. This results in a large power consumption for the system and increases the risk of browning, affecting the color of the product.

[0003] 2. During the start-up phase of the MVR evaporator, purified water is required initially. Once the system reaches a stable state, syrup is introduced for concentration, consuming a significant amount of water. Simultaneously, the process of gradually increasing the dry solids content of the evaporator discharge from 0% to 77% consumes substantial amounts of electricity. During shutdown, the 77% concentrated sugar needs to be rinsed with a large amount of water to reduce the concentration to 0%, before resuming water circulation. Shutdown can only proceed after stabilization, requiring additional electricity for equipment cleaning. This waste of electricity and water is essentially unproductive, resulting in energy and material waste and impacting production efficiency.

[0004] 3. The temperature of the syrup discharged from the evaporator is above 85℃. Even after heat exchange during feeding and discharging, this portion of the syrup still has a temperature above 60℃ and requires cooling with circulating cooling water. After the temperature of this circulating cooling water is raised, cooling fans are needed to cool it down, which undoubtedly increases the power consumption of the fans and cooling water pumps, increases the evaporation of cooling water, is not energy-saving, and does not conform to the current environmental protection concept.

[0005] 4. In summer, the discharge temperature cannot be reduced to below 35°C by circulating cooling water alone. It is necessary to use chilled water with a lower temperature for cooling, which requires the corresponding chiller unit, chilled water tank, etc. However, this part of the equipment only operates in summer and cannot be used in winter. The equipment is expensive and has a low utilization rate. Summary of the Invention

[0006] The present invention addresses the problem of overly simplistic solutions in existing technologies by providing a significantly different solution. To overcome the aforementioned deficiencies of existing technologies, the present invention provides an energy-saving evaporation and centralized heating device for starch sugar, aiming to solve the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides an energy-saving evaporation and centralized heating device for starch sugar, comprising: an evaporation section and a heating section. The evaporation section includes a primary low-pressure evaporator and a secondary low-pressure evaporator. A vacuum pump is connected to one side of the primary and secondary low-pressure evaporators via a pipeline, and a steam pipeline is connected to one side of the primary and secondary low-pressure evaporators via a pipeline. The primary low-pressure evaporator is connected to a feed pump, a first circulation pump, a second circulation pump, and a primary discharge pump via a pipeline. The secondary low-pressure evaporator is connected to a third circulation pump, a fourth circulation pump, and a secondary discharge pump via a pipeline, forming a zero-water-use start-up and shutdown function.

[0008] The evaporation stage of the evaporation section employs low-pressure, high-vacuum evaporation to lower the evaporation temperature, effectively reducing evaporation power and steam consumption. It also avoids issues such as yellowing of the product color and a burnt smell caused by high-temperature Maillard reactions. The primary and secondary low-pressure evaporators are evacuated to below 470 mbar using a vacuum pump and then circulated with steam to heat the evaporators to above 82°C. Temperature sensors (not shown in the diagram) are pre-installed on both the primary and secondary low-pressure evaporators.

[0009] Preferably, the start-up steps of the evaporation section are as follows: S1 Vacuuming: Click the sugar inlet start button in the control system to enter the zero-water sugar inlet start-up sequential control state, and start the vacuum pump to pump the first-stage low-pressure evaporator and the second-stage low-pressure evaporator to below 470mbar. S2 Feed: The sugar solution is pumped into the first-stage low-pressure evaporator and the second-stage low-pressure evaporator through a pre-set pipeline; S3 Pump Start-up: Start each circulation pump in sequence to fill the first-stage low-pressure evaporator and the second-stage low-pressure evaporator with sugar solution; S4 heating: High-temperature steam is injected into the shells of the first-stage and second-stage low-pressure evaporators through a pre-set steam pipeline, raising the temperature of the sugar solution in the tubes of the first-stage and second-stage low-pressure evaporators to above 82°C. S5 Start Compressor: After the vacuum and temperature reach the required level, start the compressor connected to the first-stage evaporator and the second-stage evaporator. The evaporator will start to gradually run and evaporate, and the system will enter the dilute sugar circulation state. S6 Concentration: Click the Start Production button in the control system to steadily increase the compressor operating frequency to the required level. As evaporation proceeds, the discharge concentration gradually increases. S7 Discharge: When the evaporator discharge concentration reaches the required level, the syrup is discharged into a storage tank for storage; The shutdown procedure for the evaporator section is as follows: S1 Stop Production: Click the Stop Production button in the control system, and the system will enter the zero-water-use stop production sequential control program; S2: The feed pump continues to run; S3 compressor reduction: The compressor operating frequency gradually decreases; S4 Concentration Reduction: As the compressor frequency gradually decreases, the sugar solution discharge concentration gradually decreases to the same level as the feed concentration; S5 Stop Compressor: The compressor operating frequency continues to gradually decrease until the compressor stops; S6 Pump Stop: Stop the inlet pump and all circulating pumps, and the unit will shut down.

[0010] This design enables the evaporation stage of the evaporation section to operate with zero water usage during start-up and shutdown, demonstrating the environmental friendliness of this device.

[0011] Preferably, the heating unit includes a water storage tank and a chilled water tank, which are arranged in parallel and connected by an overflow pipe.

[0012] Once the water storage tank is full, tap water flows into the chilled water tank through the middle overflow pipe until both tanks are full.

[0013] Preferably, the top of the water storage tank is connected to a tap water pipe, and the tap water pipe is equipped with a tap water inlet valve. The bottom of the water storage tank and the chilled water tank are equipped with outlet pipes. The top of the chilled water tank is equipped with an inlet pipe, and the other end of the inlet pipe is connected to the chiller. The inlet pipe is equipped with a chiller return water valve. Meanwhile, the other end of the chiller is connected to the chiller circulating water pump via a pipe.

[0014] The tap water inlet valve uses an existing structure on the market to control the flow rate of tap water in the tap water pipe, while the outlet pipe is used to drain water from the storage tank and chilled water tank.

[0015] A hot water return valve is pre-installed on the inlet pipe at the top of the chilled water tank, and a pressure gauge is pre-installed on the pipe connecting the chiller circulating water pump and the chiller.

[0016] Preferably, the heating unit further includes a chilled water pump, which is located on one side of the water storage tank. One end of the chilled water pump is connected to a pre-set outlet pipe at the bottom of the chilled water tank via a pipe, and this pipe is also connected to the pre-set outlet pipe at the bottom of the water storage tank and the other end of the chiller circulating water pump.

[0017] The pipe connecting one end of the chilled water pump to the outlet pipe at the bottom of the chilled water tank is equipped with a tap water inlet valve and a chilled water inlet valve.

[0018] Preferably, the heating unit further includes a water pump located on one side of the chilled water tank, with one end of the water pump connected to a pre-installed water outlet pipe at the bottom of the chilled water tank via a pipe, and this pipe is also connected to one end of an air conditioning water pump.

[0019] The other end of the water pump is connected to an external hot water tank via a pipe, and the other end of the air conditioner water pump is connected to an external air conditioner via a pipe, with a pressure gauge pre-installed on the pipe.

[0020] Preferably, the heating unit further includes a primary cooling heat exchanger, a secondary cooling heat exchanger, and a tertiary cooling heat exchanger. The primary, secondary, and tertiary cooling heat exchangers are arranged in parallel from left to right. One end of the primary cooling heat exchanger is connected to the discharge end of the secondary discharge pump via a pipe, and the other end of the primary cooling heat exchanger is connected to the secondary cooling heat exchanger via a pipe. The secondary cooling heat exchanger is connected to the tertiary cooling heat exchanger via a pipe.

[0021] The primary, secondary, and tertiary cooling heat exchangers utilize existing commercially available structures. Users can sequentially set the cooling temperature of the tertiary heat exchanger according to their needs, thereby using tertiary chilled water or circulating cooling water to cool the discharged syrup to 27-35℃ as required. The pipes connecting the primary and secondary cooling heat exchangers are pre-installed with primary cooling water outlet valves, primary chilled water outlet valves, secondary cooling water outlet valves, secondary chilled water outlet valves, and temperature sensors. The pipes connecting the secondary and tertiary cooling heat exchangers are also pre-installed with temperature sensors.

[0022] Preferably, the top of the primary cooling heat exchanger is connected to a circulating cooling water inlet pipe, and the circulating cooling water inlet pipe is connected to the other end of the chilled water pump via a pipe.

[0023] The circulating cooling water inlet pipe is pre-installed with a primary cooling water inlet valve and a primary cooling regulating valve. The circulating cooling water inlet pipe is connected to the secondary cooling heat exchanger and the tertiary cooling heat exchanger via pipelines. The pipelines are also pre-installed with a primary chilled water inlet valve, a secondary cooling water inlet valve, a secondary cooling regulating valve, a tertiary cooling water inlet valve, a tertiary chilled water inlet valve, and a tertiary cooling regulating valve.

[0024] Preferably, a circulating cooling water return pipe is connected to the pipe connecting the primary cooling heat exchanger and the secondary cooling heat exchanger.

[0025] This creates a cooling water recycling function, demonstrating the practicality of this device.

[0026] Preferably, the end of the tertiary cooling heat exchanger furthest from the secondary cooling heat exchanger is connected to a water storage tank via a pipe, and this pipe is connected to the circulating cooling water return pipe, and this pipe is also connected to the pipe between the primary cooling heat exchanger and the secondary cooling heat exchanger.

[0027] This pipeline is pre-installed with a three-stage chilled water outlet valve, a chilled water return main valve, and a three-stage cooling water outlet valve.

[0028] The beneficial effects of this invention are: 1. This invention employs low-pressure, high-vacuum evaporation during the evaporation stage, thereby reducing the evaporation temperature and effectively lowering evaporation power and steam consumption. It also avoids the yellowing of the product color and burnt smell caused by high-temperature Maillard reactions, thus improving product quality.

[0029] 2. This invention develops a zero-water start / stop process and optimizes the start / stop process, effectively shortening the start / stop time and the time for increasing / decreasing concentration, reducing the power consumption and steam consumption during start / stop, reducing the amount of waste generated due to water intake, and improving production efficiency.

[0030] 3. In winter, this invention utilizes unused water tanks to store both cold and hot water. Heat exchange with low-temperature tap water achieves the purpose of cooling the product, thus improving the utilization rate of the water tanks. Using this hot water for heat exchange in production can effectively reduce the amount of steam required. Simultaneously, this hot water can be used for centralized heating in central air conditioning systems, improving the utilization rate of central air conditioning and enhancing office comfort.

[0031] 4. At the same time, by using low-temperature tap water for MVR discharge cooling and heat exchange, the present invention eliminates the need for circulating cooling water in winter, thereby reducing the power consumption of cooling fans and cooling water pumps. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a front view of the overall structure of a specific embodiment of the present invention; Figure 2This is a front view structural diagram of a primary low-pressure evaporator according to a specific embodiment of the present invention; Figure 3 This is a front view schematic diagram of the primary cooling heat exchanger according to a specific embodiment of the present invention; Figure 4 This is a front view structural diagram of the chilled water tank according to a specific embodiment of the present invention.

[0034] Part Name 1. Primary low-pressure evaporator; 2. Secondary low-pressure evaporator; 3. Water storage tank; 4. Chilled water tank; 5. Primary cooling heat exchanger; 6. Secondary cooling heat exchanger; 7. Tertiary cooling heat exchanger. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings. Preferably, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0036] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] Please see Figures 1 to 4This invention provides an energy-saving evaporation and centralized heating device for starch sugar, comprising: an evaporation section and a heating section. The evaporation section includes a primary low-pressure evaporator 1 and a secondary low-pressure evaporator 2. A vacuum pump is connected to one side of each of the primary and secondary low-pressure evaporators 1 and 2 via a pipeline, and a steam pipeline is also connected to one side of each. The primary low-pressure evaporator 1 is connected via a pipeline to a feed pump, a first circulation pump, a second circulation pump, and a primary discharge pump. The secondary low-pressure evaporator 2 is connected via a pipeline to a third circulation pump, a fourth circulation pump, and a second... Preferably, the start-up steps of the evaporation section are as follows: S1 Vacuuming: Click the sugar inlet start-up button in the control system to enter the zero-water sugar inlet start-up sequential control state, and start the vacuum pump to evacuate the first-stage low-pressure evaporator 1 and the second-stage low-pressure evaporator 2 to below 470 mbar; S2 Feeding: Pump the sugar solution into the first-stage low-pressure evaporator 1 and the second-stage low-pressure evaporator 2 through the preset pipeline; S3 Pump Start: Start each circulation pump in sequence to fill the first-stage low-pressure evaporator 1 and the second-stage low-pressure evaporator 2 with sugar solution; S4 Heating: Heate the sugar solution through the preset heating... The steam pipeline injects high-temperature steam into the shell layers of the primary low-pressure evaporator 1 and the secondary low-pressure evaporator 2, raising the temperature of the sugar solution in the tube layers of these evaporators to above 82°C. S5: Compressor Start: Once the required vacuum and temperature are achieved, start the compressor connected to the primary and secondary evaporators. The evaporators begin gradual evaporation, and the system enters a dilute sugar circulation state. S6: Concentration: Click the "Start Production" button in the control system to steadily increase the compressor's operating frequency to the required level. As evaporation progresses, the discharge concentration gradually increases. Increase; S7 Discharge: When the evaporator discharge concentration increases to the required level, the syrup is discharged into the storage tank for preservation; The shutdown procedure for the evaporation section is as follows: S1 Stop Production: Click the stop production button in the control system, and the system enters the zero-water stop production sequential control program; S2: The feed pump continues to run; S3 Reduce Compressor Frequency: The compressor operating frequency gradually decreases; S4 Reduce Concentration: As the compressor frequency gradually decreases, the syrup discharge concentration gradually decreases to the same level as the feed concentration; S5 Stop Compressor: The compressor operating frequency continues to gradually decrease until the compressor stops;S6 Pump Stop: Stops the inlet pump and all circulating pumps, shutting down the unit. The heating section includes a water storage tank 3 and a chilled water tank 4, which are arranged in parallel and connected by an overflow pipe. A water supply pipe is connected to the top of the water storage tank 3, and a water inlet valve is installed on the water supply pipe. Water outlet pipes are installed at the bottom of the water storage tank 3 and the chilled water tank 4, and a water inlet pipe is installed at the top of the chilled water tank 4. The other end of the water inlet pipe is connected to the chiller, and a chiller return valve is installed on the water inlet pipe. The system includes a water valve, and the other end of the chiller is connected to the chiller circulating water pump via a pipe. The heating unit also includes a chilled water pump, located on one side of the storage tank 3. One end of the chilled water pump is connected via a pipe to a pre-installed outlet pipe at the bottom of the chilled water tank 4. This pipe is also connected to both the pre-installed outlet pipe at the bottom of the storage tank 3 and the other end of the chiller circulating water pump. The heating unit also includes a pumping pump, located on one side of the chilled water tank 4. One end of the pumping pump is connected via a pipe to a pre-installed outlet pipe at the bottom of the chilled water tank 4. This pipeline is also connected to one end of the air conditioning water pump. The heating section also includes a primary cooling heat exchanger 5, a secondary cooling heat exchanger 6, and a tertiary cooling heat exchanger 7. The primary cooling heat exchanger 5, the secondary cooling heat exchanger 6, and the tertiary cooling heat exchanger 7 are arranged in parallel from left to right. One end of the primary cooling heat exchanger 5 is connected to the discharge end of the secondary discharge pump via a pipeline, and the other end of the primary cooling heat exchanger 5 is connected to the secondary cooling heat exchanger 6 via a pipeline. The secondary cooling heat exchanger 6 is connected to the tertiary cooling heat exchanger 7 via a pipeline. The primary cooling heat exchanger 5 is connected to a circulating cooling water inlet pipe at its top, which is connected to the other end of a chilled water pump via a pipe. A circulating cooling water return pipe is connected to the pipe connecting the primary cooling heat exchanger 5 and the secondary cooling heat exchanger 6. The end of the tertiary cooling heat exchanger 7 furthest from the secondary cooling heat exchanger 6 is connected to a water storage tank 3 via a pipe, which is also connected to the circulating cooling water return pipe and the pipe between the primary cooling heat exchanger 5 and the secondary cooling heat exchanger 6.

[0038] Specific Implementation Example 1: MVR Energy-Saving Evaporation In this embodiment: ①The internal pressure of the first-stage and second-stage evaporators is reduced to below 470mbar using a vacuum pump.

[0039] ②Start the feed pump to pump the 40% concentration sugar solution into the first-stage low-pressure evaporator.

[0040] ③ Start each circulation pump and discharge pump in sequence. The 40% concentration syrup is filled into the first-stage low-pressure evaporator by the first circulation pump and the second circulation pump, and then filled into the second-stage low-pressure evaporator by the first-stage discharge pump, the third circulation pump and the fourth circulation pump in sequence.

[0041] ④ Introduce steam to heat the two evaporators to above 82°C.

[0042] ⑤ Start the compressor connected to the first-stage and second-stage evaporators and gradually increase the compressor power to gradually increase the concentration of the syrup output.

[0043] ⑥ When the syrup discharge concentration is ≥76.5%, the syrup begins to be discharged, and the MVR enters a stable operating state.

[0044] Specific Implementation Example 2: Heat Recovery and Central Heating System In this embodiment: Summer Mode: ① Open the tap water inlet valve of the water tank, and tap water enters the storage tank. When the storage tank is full, the tap water enters the chilled water tank through the middle overflow pipe and fills both water tanks.

[0045] ② Open the valve before the chiller circulating water pump and the chiller return water valve. Use the chiller to make the water in the storage tank into 5°C chilled water. After the 5°C chilled water is filled, it flows into the 20°C tank through the middle overflow pipe. Repeat this process until both tanks are filled with 5°C chilled water.

[0046] ③ Open the chilled water inlet valve and the chilled water return valve, open the chilled water valve, and pump 5℃ cold water into the discharge cooling heat exchanger to cool the syrup sequentially.

[0047] ④ Set the cooling temperature of the three-stage cooling heat exchanger according to the requirements, and use three-stage chilled water or circulating cooling water to cool the discharged syrup to 27~35℃ according to the actual needs.

[0048] ⑤ Return the chilled water to the storage tank. Once the temperature of both tanks becomes hot, cool the hot water according to step ②.

[0049] ⑥ Open the valve in front of the air conditioning water pump to pump 5℃ cold water into the central air conditioning system of each office, thereby cooling each office and maintaining a comfortable working environment.

[0050] Winter mode: ① Open the tap water inlet valve of the water tank, and tap water enters the storage tank. When the storage tank is full, the tap water enters the chilled water tank through the middle overflow pipe and fills both water tanks.

[0051] ② Open the MVR tap water inlet valve and the MVR hot water return valve, and turn on the MVR chilled water pump to pump tap water into the three-stage cooling heat exchanger.

[0052] ③ Set the cooling temperature of the three-stage cooling heat exchanger according to the requirements, and use three-stage tap water or circulating cooling water to cool the MVR discharge according to the actual needs.

[0053] ④ After heat exchange, the tap water is heated and then enters the chilled water tank. Open the valve before the air conditioning water pump to pump the hot water from the 5°C chilled water tank into the central air conditioning units in each office, thereby heating each office to maintain a comfortable working environment.

[0054] ⑤ The water in the storage tank is continuously used for cooling the MVR discharge through a chilled water pump. The temperature of the hot water in the 5°C cold water tank is continuously raised. When the temperature becomes too high, the hot water is pumped away by a water pump for heat exchange in production, thus realizing the recovery of MVR heat.

[0055] ⑥ After the hot water is removed and the liquid level in the tank becomes too low, water is replenished through step ① to achieve heat recycling.

[0056] Specific Implementation Example 3: MVR Energy-Saving Shutdown In this embodiment: ①After the syrup has evaporated, gradually reduce the compressor speed to 1000 rpm, and the syrup output concentration will gradually decrease.

[0057] ② Keep the feed and circulation pump running, continue to reduce the compressor speed to below 500 rpm, and then stop the compressor.

[0058] ③ After the compressor has completely stopped, stop all pumps.

[0059]

[0060] Table 1 Comparison of Data and Process Flow According to Table 1: 1. The evaporation stage of this invention uses low-pressure evaporation at 470 mbar, with an evaporation temperature below 83°C. Traditional MVR evaporators use pressure evaporation at 510 mbar, with an evaporation temperature above 85°C, or even higher. The lower evaporation pressure and temperature mean less electricity is needed to maintain the high temperature and pressure, resulting in greater energy savings and reducing electricity consumption per ton of sugar by more than 0.5 kWh.

[0061] 2. The evaporation stage of this invention employs a zero-water process for start-up and shutdown. This ensures that the syrup does not undergo a Maillard reaction, and during start-up, the syrup concentration is increased from 41% to 77% instead of from 0%. During shutdown, no water is needed for water transport. Each start-up and shutdown saves over 40 m³ of purified water, reduces low-concentration sweet water production by over 40 m³, reduces external drainage by 2 m³, saves 80 kWh of electricity, saves approximately 400 kg of steam, and saves over 30 minutes of concentration time.

[0062] 3. In winter, this invention uses low-temperature tap water for heat exchange with the MVR-discharged syrup, thus recovering heat. Traditional processes use circulating cooling water for cooling, and once the circulating cooling water temperature rises, a fan is used to cool it down. This heat is not recovered, and it also increases the electricity consumption for circulating cooling water refrigeration. By recovering this heat and using it for production heating and heat exchange, based on an annual production of 200,000 tons of fructose syrup, it can save up to 2,000 tons of steam consumption annually, over 20,000 kWh of electricity used for circulating cooling water pumps and fans, and over 1,000 tons of circulating cooling water evaporation. This invention has a significant energy-saving effect.

[0063] 4. This invention utilizes a chiller water tank to recycle and store the recovered hot water, which is then used for heating in a central air conditioning system. This not only improves the utilization rate of the chiller water tank but also enhances the office environment.

[0064] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A starch sugar energy-saving evaporation and centralized heating device, comprising: The evaporation section and the heating section are characterized in that the evaporation section includes a primary low-pressure evaporator (1) and a secondary low-pressure evaporator (2), a vacuum pump is connected to one side of the primary low-pressure evaporator (1) and the secondary low-pressure evaporator (2) via a pipeline, and a steam pipeline is connected to one side of the primary low-pressure evaporator (1) and the secondary low-pressure evaporator (2), a feed pump, a first circulation pump, a second circulation pump and a primary discharge pump are connected to the primary low-pressure evaporator (1) via a pipeline, and a third circulation pump, a fourth circulation pump and a secondary discharge pump are connected to the secondary low-pressure evaporator (2) via a pipeline.

2. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The start-up procedure for the evaporator section is as follows: S1 Vacuuming: Click the sugar inlet start button in the control system to enter the zero water sugar inlet start-up sequential control state, and start the vacuum pump to evacuate the first-stage low-pressure evaporator (1) and the second-stage low-pressure evaporator (2) to below 470mbar. S2 Feed: The sugar solution is pumped into the first-stage low-pressure evaporator (1) and the second-stage low-pressure evaporator (2) through a pre-set pipeline; S3 Pump Start: Start each circulation pump in sequence to fill the first-stage low-pressure evaporator (1) and the second-stage low-pressure evaporator (2) with sugar solution. S4 Heating: High-temperature steam is injected into the shells of the first-stage low-pressure evaporator (1) and the second-stage low-pressure evaporator (2) through a preset steam pipeline, raising the temperature of the sugar solution in the tubes of the first-stage low-pressure evaporator (1) and the second-stage low-pressure evaporator (2) to above 82°C. S5 Start Compressor: After the vacuum and temperature reach the required level, start the compressor connected to the first-stage evaporator and the second-stage evaporator. The evaporator will start to gradually run and evaporate, and the system will enter the dilute sugar circulation state. S6 Concentration: Click the Start Production button in the control system to steadily increase the compressor operating frequency to the required level. As evaporation proceeds, the discharge concentration gradually increases. S7 Discharge: When the evaporator discharge concentration reaches the required level, the syrup is discharged into a storage tank for storage; The shutdown procedure for the evaporator section is as follows: S1 Stop Production: Click the Stop Production button in the control system, and the system will enter the zero-water-use stop production sequential control program; S2: The feed pump continues to run; S3 compressor reduction: The compressor operating frequency gradually decreases; S4 Concentration Reduction: As the compressor frequency gradually decreases, the concentration of the sugar solution discharged gradually decreases to the same level as the feed concentration; S5 Stop Compressor: The compressor operating frequency continues to gradually decrease until the compressor stops; S6 Pump Stop: Stop the inlet pump and all circulating pumps, and the unit will shut down.

3. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The heating unit includes a water storage tank (3) and a chilled water tank (4), which are arranged in parallel and are connected by an overflow pipe.

4. The starch sugar energy-saving evaporation and centralized heating device as described in claim 3, characterized in that, The top of the water storage tank (3) is connected to a tap water pipe, and a tap water inlet valve is pre-installed on the tap water pipe. The bottom of the water storage tank (3) and the chilled water tank (4) are pre-installed with outlet pipes. The top of the chilled water tank (4) is pre-installed with an inlet pipe, and the other end of the inlet pipe is connected to the chiller. A chiller return water valve is pre-installed on the inlet pipe. At the same time, the other end of the chiller is connected to the chiller circulating water pump through a pipe.

5. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The heating unit also includes a chilled water pump, which is located on one side of the water storage tank (3). One end of the chilled water pump is connected to the water outlet pipe at the bottom of the chilled water tank (4) via a pipe, and this pipe is also connected to the water outlet pipe at the bottom of the water storage tank (3) and the other end of the chiller circulating water pump.

6. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The heating unit also includes a water pump, which is located on one side of the chilled water tank (4). One end of the water pump is connected to the water outlet pipe at the bottom of the chilled water tank (4) via a pipe, and this pipe is also connected to one end of the air conditioning water pump.

7. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The heating unit also includes a primary cooling heat exchanger (5), a secondary cooling heat exchanger (6) and a tertiary cooling heat exchanger (7). The primary cooling heat exchanger (5), the secondary cooling heat exchanger (6) and the tertiary cooling heat exchanger (7) are arranged in parallel from left to right. One end of the primary cooling heat exchanger (5) is connected to the discharge end of the secondary discharge pump via a pipe, and the other end of the primary cooling heat exchanger (5) is connected to the secondary cooling heat exchanger (6) via a pipe. The secondary cooling heat exchanger (6) is connected to the tertiary cooling heat exchanger (7) via a pipe.

8. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The top of the primary cooling heat exchanger (5) is connected to a circulating cooling water inlet pipe, and the circulating cooling water inlet pipe is connected to the other end of the chilled water pump via a pipe.

9. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The pipe connecting the primary cooling heat exchanger (5) and the secondary cooling heat exchanger (6) is connected to a circulating cooling water return pipe.

10. The starch sugar energy-saving evaporation and centralized heating device as described in claim 1, characterized in that, The end of the third-stage cooling heat exchanger (7) away from the second-stage cooling heat exchanger (6) is connected to the water storage tank (3) via a pipe, and this pipe is connected to the circulating cooling water return pipe, and this pipe is connected to the pipe between the first-stage cooling heat exchanger (5) and the second-stage cooling heat exchanger (6).

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