A method for drying sludge using waste heat from carbon dioxide

Abstract

This invention provides a method for drying sludge using waste heat from carbon dioxide. A heat exchange device discharges high-temperature carbon dioxide gas as high-temperature water, reducing the temperature at which the carbon dioxide enters the liquefaction system, lowering refrigeration energy consumption, and ensuring equipment safety. Simultaneously, the high-temperature water is fed into a warm water pipe for sludge drying, improving drying efficiency and further reducing the moisture content of the discharged sludge. A pre-set sludge drying model is selected based on the sludge drying requirements, determining sludge laying parameters and warm water pipe usage parameters. This provides the most effective sludge drying measures for the initial sludge parameters, meeting the corresponding drying needs. The method boasts high drying efficiency and minimal intervention. Furthermore, the pre-set sludge drying model is corrected based on real-time detected sludge and warm water pipe parameters, further improving its accuracy and stability.

Description

Technical Field

[0001] This invention relates to the technical field of sludge drying, and specifically to a method for drying sludge using waste heat from carbon dioxide. Background Technology

[0002] Existing methods for co-treating food waste and sludge can not only stably treat organic waste, rendering it harmless and reducing its volume, but also produce usable biogas and garden biocarbon soil, effectively achieving recycling and utilization.

[0003] In existing biogas purification processes for natural gas production, desulfurization and impurity removal are typically performed, followed by temperature-controlled removal of carbon dioxide from the biogas to produce natural gas with methane purity exceeding 95%. During this process, approximately one-third of the carbon dioxide gas in the original biogas is directly released into the atmosphere, resulting in energy waste and carbon emissions. Furthermore, capturing this high-temperature carbon dioxide gas to prepare liquid carbon dioxide requires ambient temperatures reaching 80-90°C. Such high temperatures can adversely affect the equipment used in liquid carbon dioxide production, shortening the lifespan of the gas chambers and increasing the energy consumption of the downstream refrigeration unit.

[0004] Existing solar-powered drying processes involve conveying dehydrated biogas residue into a drying greenhouse via a conveyor, where a spreading machine evenly distributes it onto the drying bed. A turning machine and a ventilator continuously mix, crush, and ventilate the residue to achieve drying. In summer, with ample sunlight, the greenhouse temperature can reach over 50°C, and the moisture content of the biogas residue sludge can be reduced to 30%, demonstrating a significant drying effect. However, in winter, due to shorter daylight hours and lower temperatures, the moisture content of the biogas residue sludge can only be maintained at around 55%. To address this issue, it is necessary to add equipment such as air conditioners and heat pumps to increase the air temperature inside the drying greenhouse. While this improves the drying effect, it also consumes too much electricity.

[0005] Therefore, there is an urgent need to provide a method for drying sludge using waste heat from carbon dioxide to address the defects and shortcomings of the existing technologies. Summary of the Invention

[0006] To address the deficiencies and shortcomings of the existing technology, this invention provides a method for drying sludge using waste heat from carbon dioxide.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for drying sludge using waste heat from carbon dioxide, characterized by comprising the following steps:

[0009] 1) After anaerobic digestion, methane and carbon dioxide are separated from the biogas using a temperature-switching method;

[0010] 2) The high-temperature carbon dioxide gas obtained in step 1) is passed into a heat exchanger, and the heat exchanger discharges the heat after heat exchange through high-temperature water.

[0011] 3) Pass the high-temperature water discharged in step 2) into a temporary storage tank for temporary storage;

[0012] 4) Select the sludge drying preset model in the control platform, input the initial sludge parameters into the sludge drying preset model, and determine the sludge laying parameters and the heating water pipe usage parameters;

[0013] 5) The high-temperature water in the temporary storage tank in step 3) is pumped into the underground heating pipe in the sludge drying area;

[0014] 6) The biogas residue sludge is evenly distributed on the top of the heated drying bed through the bedding layer. The biogas residue sludge is heated and dried by high temperature water in the underground hot water pipe at the bottom. At the same time, the corresponding parameters are collected and sent to the preset model of the control platform.

[0015] 7) Determine whether the real-time temperature difference between the inlet and outlet of each heating water pipe meets the preset conditions for the inlet and outlet of the heating water pipe. Proceed to the next step only if it is determined to meet the conditions.

[0016] 8) Determine whether the real-time temperature difference between the inlet and outlet of the adjacent heating water pipe meets the preset conditions for adjacent heating water pipes. Proceed to the next step only if it is determined to meet the conditions.

[0017] 9) Sample the biogas residue sludge at the top of the heated drying bed at regular intervals. When the moisture content of the sampled sludge meets the preset threshold range, proceed to the next step. When the moisture content of the sampled sludge exceeds the preset threshold range, the control platform performs corresponding sludge drying control on the sludge drying zone.

[0018] 10) The control platform uses a detection device to monitor sludge parameters and heating water pipe parameters during the sludge drying process in real time and sends them to the control platform.

[0019] 11) The control platform corrects the preset sludge drying model based on the sludge parameters and heating water pipe parameters detected in real time during the sludge drying process.

[0020] As a further preferred embodiment of the present invention, the water tank in step 3) is equipped with a water tank temperature detection device and a water tank level detection device, and a connection switch is provided between the water tank and the water pump.

[0021] When the high-temperature water inside the water tank is higher than the preset liquid level and within the preset temperature range, the switch between the water tank and the water pump is opened to connect them.

[0022] When the high-temperature water inside the tank is lower than the preset liquid level, the switch between the water tank and the water pump will be turned off; when the high-temperature water inside the tank exceeds the preset temperature range, the switch between the water tank and the water pump will be turned off, and the water tank temperature control device will be turned on to maintain the temperature inside the water tank within a suitable temperature range.

[0023] As a further preferred embodiment of the present invention, in step 4),

[0024] Select a preset sludge drying model in the control platform according to the sludge drying requirements;

[0025] The initial parameters of the sludge include at least the type of sludge, the initial moisture content of the sludge, and the sludge mass.

[0026] The sludge laying parameters include at least the sludge laying location and the footprint.

[0027] The parameters for using the heating water pipes include at least the number of heating water pipes used, the number of water pumps used, and the initial output power.

[0028] As a further preferred embodiment of the present invention, in step 6), the floor space of the bedding layer is larger than the floor space of the biogas residue sludge laid on top.

[0029] As a further preferred embodiment of the present invention, in step 7), the real-time temperature of the inlet and outlet of each heating water pipe is detected and recorded respectively.

[0030] The system is considered to meet the preset inlet and outlet conditions of the heating water pipes only when the real-time temperature difference between the inlet and outlet of each heating water pipe is within the first preset threshold range; otherwise,

[0031] If the real-time temperature difference between the inlet and outlet of at least one hot water pipe exceeds the first preset threshold range, it is determined that the preset conditions for the inlet and outlet of the hot water pipe are not met.

[0032] In a further preferred embodiment of the present invention, in step 8), the real-time temperatures of the inlet and outlet of adjacent warm water pipes are detected and recorded respectively.

[0033] The adjacent heating pipes are considered to meet the preset conditions only if the real-time temperature difference between the inlet and outlet of both adjacent heating pipes is within the second preset threshold range; otherwise,

[0034] If the real-time temperature difference between the inlet or outlet of at least one adjacent heating water pipe exceeds the second preset threshold range, it is determined that the preset conditions for adjacent heating water pipes are not met.

[0035] As a further preferred embodiment of the present invention, in step 9),

[0036] When the sludge moisture content is higher than the preset threshold range, the control platform will implement corresponding sludge drying control in the sludge drying zone, including at least the following control methods:

[0037] Control method A1: Increase the flow rate at the inlet and outlet of the heating water pipe;

[0038] Control method A2: Increase the inlet temperature of the heating water pipe;

[0039] Control method A3: Increase the sludge laying area; and

[0040] Control method A4: Shorten the sludge renewal cycle;

[0041] When the sludge moisture content is lower than the preset threshold range, the control platform performs corresponding sludge drying control in the sludge drying zone, including at least the following control methods:

[0042] Control method B1: Reduce the flow rate at the inlet and outlet of the heating water pipe;

[0043] Control method B2: Reduce the inlet temperature of the heating water pipe;

[0044] Control method B3: Reduce the sludge laying area; and

[0045] Control method B4: Extend the sludge renewal cycle.

[0046] As a further preferred embodiment of the present invention, when the sludge moisture content is higher than the preset threshold range, the priority of the control mode satisfies control mode A2 > control mode A1 > control mode A4 > control mode A3.

[0047] As a further preferred embodiment of the present invention, when the sludge moisture content is lower than the preset threshold range, the priority of the control mode satisfies control mode B1 > control mode B4 > control mode B3 > control mode B2.

[0048] As a further preferred embodiment of the present invention, in step 9), when sampling and testing the biogas residue sludge at the top of the heated drying bed at each cycle time, it is necessary to simultaneously take several samples of the biogas residue sludge at both the outer edge and the inner edge of the bed, and the moisture content of the sampled sludge is the average value of the multiple sampling test results.

[0049] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0050] 1) This invention provides a method for drying sludge using waste heat from carbon dioxide. The high-temperature carbon dioxide gas is discharged as high-temperature water through a heat exchange device, which reduces the temperature at which carbon dioxide enters the liquefaction system, reduces the energy consumption of the refrigeration unit, and ensures equipment safety. At the same time, the high-temperature water is sent into the warm water pipe for sludge drying, which improves the sludge drying efficiency and further reduces the output moisture content of the biogas residue sludge.

[0051] 2) This invention provides a method for drying sludge using waste heat from carbon dioxide. A pre-set sludge drying model is selected based on the sludge drying requirements, and initial sludge parameters are input into the model to determine sludge laying parameters and heating water pipe usage parameters. This provides the most effective sludge drying measures for the initial sludge parameters, thus meeting the corresponding sludge drying requirements. The method boasts high drying efficiency and requires minimal intervention. Furthermore, the pre-set sludge drying model is corrected based on real-time detected sludge and heating water pipe parameters during the drying process, further improving its accuracy and stability.

[0052] 3) This invention provides a method for drying sludge using waste heat from carbon dioxide, which includes determining whether the real-time temperature difference between the inlet and outlet of each warm water pipe meets the preset conditions for the inlet and outlet of the warm water pipe, and determining whether the real-time temperature difference between the inlet and outlet of adjacent warm water pipes meets the preset conditions for adjacent pipes. Therefore, it can ensure that the temperature change between the inlet and outlet of the warm water pipe can guarantee the sludge drying efficiency while ensuring the overall drying efficiency and drying stability of the sludge laying area.

[0053] 4) This invention provides a method for drying sludge using waste heat from carbon dioxide. When the moisture content of the sampled sludge exceeds the preset threshold range, the control platform performs corresponding sludge drying control on the sludge drying zone, thereby intervening in the drying process in a timely manner. This achieves the best drying effect for sludge at different time periods while saving energy and improving drying efficiency. Attached Figure Description

[0054] Figure 1 This is a logical structure diagram of the present invention.

[0055] Figure 2 This is a flowchart of the steps of the present invention. Detailed Implementation

[0056] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] like Figure 1-2 The following is a method for drying sludge using waste heat from carbon dioxide, as provided in this embodiment, comprising the following steps:

[0059] 1) After anaerobic digestion, methane and carbon dioxide are separated from biogas by a temperature-switching method. At this time, the carbon dioxide gas is in a high-temperature gaseous state.

[0060] 2) The high-temperature carbon dioxide gas obtained in step 1) is passed into a heat exchange device, and the heat exchange device discharges the heat after heat exchange through high-temperature water; the heat exchange device can be a cooling device for carbon dioxide liquefaction pretreatment disclosed in CN217383529U, which replaces the cooling medium from gas to liquid, thereby realizing the discharge of high-temperature water.

[0061] 3) Pass the high-temperature water discharged in step 2) into a temporary storage tank for temporary storage; the tank is equipped with a water tank temperature detection device and a water tank level detection device, and a connection switch is installed between the tank and the water pump.

[0062] When the high-temperature water inside the tank is higher than the preset liquid level and within the preset temperature range, the switch between the tank and the pump is opened to connect them; at this time, the tank contains sufficient high-temperature water and the temperature is suitable for drying sludge.

[0063] When the high-temperature water inside the tank is lower than the preset level, the switch between the tank and the pump will be turned off. At this time, the amount of high-temperature water in the tank is insufficient and not suitable for drying sludge, so the supply of water to the warm water pipe will be stopped.

[0064] When the high-temperature water inside the tank exceeds the preset temperature range, turn off the switch between the water tank and the water pump, and turn on the water tank temperature control device to maintain the temperature inside the tank within a suitable range. At this time, the high-temperature water temperature may be too high or too low, making it unsuitable for drying sludge and requiring the use of the water tank temperature control device to maintain the temperature within a suitable range. Therefore, it is necessary to first turn off the switch between the water tank and the water pump to stop supplying water to the warm water pipe, and then turn on the water tank temperature control device to maintain the temperature inside the tank within a suitable range.

[0065] 4) In the control platform, select a sludge drying preset model according to the sludge drying requirements. The sludge drying requirements include at least the moisture content of the dried sludge and the sludge drying time. Input the initial sludge parameters into the sludge drying preset model to determine the sludge laying parameters and the heating water pipe usage parameters. In this embodiment, the initial sludge parameters include at least the sludge type, the initial moisture content of the sludge, and the sludge mass. The sludge laying parameters include at least the sludge laying location and the footprint. The heating water pipe usage parameters include at least the number of heating water pipes, the number of water pumps, and the initial output power. Preferably, in this embodiment, one water pump can be used to drive the flow of high-temperature water in a single heating water pipe. Alternatively, one pump can be used to drive the flow of high-temperature water in multiple warm water pipes. This method can save energy while achieving sludge drying. The decision can be based on a comprehensive consideration of the sludge drying requirements, the number of pumps used, and their initial output power. For example, when the sludge drying requirement is short, a higher initial output power of the pump is needed. In this case, one pump can be used to drive the flow of high-temperature water in a single warm water pipe to meet the drying requirement. Conversely, when the sludge drying requirement does not specify a drying time or the number of pumps used, and the pump output power is sufficient for the operation of multiple warm water pipes, one pump can be used to drive the flow of high-temperature water in multiple warm water pipes to further save energy.

[0066] 5) The high-temperature water in the temporary storage tank in step 3) is pumped into the underground heating pipe in the sludge drying area;

[0067] 6) The biogas residue sludge is evenly distributed on the top of the heated drying bed through a bedding layer. The size of the bedding layer is set to be larger than the size of the biogas residue sludge laid on top. This avoids the sludge from directly contacting the drying bed and may cause pollution, and also facilitates the collection of sludge after drying. The biogas residue sludge is heated and dried by high-temperature water in the underground heating pipe at the bottom. At the same time, the corresponding parameters are collected and sent to the preset model of the control platform.

[0068] 7) Determine whether the real-time temperature difference between the inlet and outlet of each heating water pipe meets the preset conditions for the inlet and outlet of the heating water pipe. Proceed to the next step only if it is determined to meet the conditions. The specific determination process is as follows: detect and record the real-time temperature of the inlet and outlet of each heating water pipe.

[0069] The system is considered to meet the preset inlet and outlet conditions of the heating water pipes only when the real-time temperature difference between the inlet and outlet of each heating water pipe is within the first preset threshold range; otherwise,

[0070] If the real-time temperature difference between the inlet and outlet of at least one hot water pipe exceeds the first preset threshold range, it is determined that the preset conditions for the inlet and outlet of the hot water pipe are not met.

[0071] The first preset threshold range is the temperature range pre-input into the control platform. By comparing the real-time temperature difference between the inlet and outlet of each warm water pipe with the first preset threshold range, the stability of the sludge drying process throughout the entire process can be guaranteed, reducing the adverse effects on the drying effect that may be caused by insufficient preheating of the warm water pipe.

[0072] 8) Determine whether the real-time temperature difference between the inlet and outlet of adjacent heating water pipes meets the preset conditions for adjacent heating water pipes. Proceed to the next step only if the condition is met. The specific determination process is as follows: detect and record the real-time temperature of the inlet and outlet of adjacent heating water pipes respectively.

[0073] The adjacent heating pipes are considered to meet the preset conditions only if the real-time temperature difference between the inlet and outlet of both adjacent heating pipes is within the second preset threshold range; otherwise,

[0074] If the real-time temperature difference between the inlet or outlet of at least one adjacent heating water pipe exceeds the second preset threshold range, it is determined that the preset conditions for adjacent heating water pipes are not met.

[0075] The second preset threshold range is the temperature range pre-input into the control platform. By comparing the real-time temperature difference between the inlet and outlet of adjacent warm water pipes with the second preset threshold range, the stability of the entire area during the sludge drying process can be ensured, reducing the adverse effects on the drying effect that may be caused by some warm water pipes being broken or leaking.

[0076] 9) Sample the biogas residue sludge at the top of the heated drying bed at regular intervals. When the moisture content of the sampled sludge meets the preset threshold range, proceed to the next step. When the moisture content of the sampled sludge exceeds the preset threshold range, the control platform performs corresponding sludge drying control on the sludge drying zone.

[0077] When sampling and testing the biogas residue sludge at the top of the heated drying bed at regular intervals, it is necessary to take several samples from both the outer edge and the inner part of the bed. The moisture content of the sludge in the sampled test is the average of the results of multiple sampling tests, so as to ensure the accuracy of the sampling test results.

[0078] The specific operating steps are as follows:

[0079] When the sludge moisture content is higher than the preset threshold range, the control platform will implement corresponding sludge drying control in the sludge drying zone, including at least the following control methods:

[0080] Control method A1: Increase the flow rate at the inlet and outlet of the warm water pipe by adjusting the corresponding water pump; thereby increasing the drying speed by adjusting the flow rate.

[0081] Control method A2: Increase the temperature of the inlet water of the heating pipe; thereby increasing the drying speed through temperature regulation.

[0082] Control method A3: Increase the sludge spreading area; thereby increasing the drying speed by adjusting the contact surface.

[0083] Control method A4: Shorten the sludge renewal cycle; thereby increasing the drying speed by adjusting the contact surface and contact time;

[0084] Furthermore, the priority of the control methods is as follows: control method A2 > control method A1 > control method A4 > control method A3. Among the control methods for reducing sludge moisture content, flow regulation and temperature regulation are the most effective. However, flow regulation requires changing the output power of the water pump, which has a greater impact on the system environment. The temperature regulation method has a smaller impact on the system environment. Therefore, the temperature regulation method is preferred. The method of adjusting the contact surface has the least impact on the sludge drying efficiency. Therefore, its priority is set to the lowest.

[0085] When the sludge moisture content is lower than the preset threshold range, the control platform performs corresponding sludge drying control in the sludge drying zone, including at least the following control methods:

[0086] Control method B1: Reduce the flow rate at the inlet and outlet of the warm water pipe by adjusting the corresponding water pump; thereby reducing the drying speed by adjusting the flow rate.

[0087] Control method B2: Reduce the inlet temperature of the hot water pipe; thereby reducing the drying rate by adjusting the temperature.

[0088] Control method B3: Reduce the sludge spreading area; thereby reducing the drying rate by adjusting the contact surface.

[0089] Control method B4: Extend the sludge renewal cycle; thereby reducing the drying rate by adjusting the contact surface and contact time;

[0090] Furthermore, the priority of the control methods is as follows: Control Method B1 > Control Method B4 > Control Method B3 > Control Method B2. Flow regulation requires reducing the output power of the water pump to effectively achieve energy saving while ensuring the drying effect, so it has the highest priority. Extending the sludge turnover cycle can reduce the energy consumption of manual labor or the power consumption of the sludge turning machine, so it has the second highest priority. Temperature regulation has a slower feedback speed on the sludge drying effect, so it has the lowest priority.

[0091] 10) The control platform uses a detection device to monitor sludge parameters and heating water pipe parameters during the sludge drying process in real time and sends them to the control platform.

[0092] 11) The control platform corrects the sludge drying preset model based on the sludge parameters and heating water pipe parameters detected in real time during the sludge drying process, so as to further improve the accuracy and stability of the sludge drying preset model.

[0093] 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 technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for drying sludge using waste heat from carbon dioxide, comprising the following steps: 1) After anaerobic digestion, methane and carbon dioxide are separated from the biogas using a temperature-switching method; 2) The high-temperature carbon dioxide gas obtained in step 1) is passed into a heat exchanger, and the heat exchanger discharges the heat after heat exchange through high-temperature water. 3) Pass the high-temperature water discharged in step 2) into a temporary storage tank for temporary storage; 4) Select the sludge drying preset model in the control platform, input the initial sludge parameters into the sludge drying preset model, and determine the sludge laying parameters and the heating water pipe usage parameters; 5) The high-temperature water in the temporary storage tank in step 3) is pumped into the underground heating pipe in the sludge drying area; 6) The biogas residue sludge is evenly distributed on the top of the heated drying bed through the bedding layer. The biogas residue sludge is heated and dried by high temperature water in the underground hot water pipe at the bottom. At the same time, the corresponding parameters are collected and sent to the preset model of the control platform. 7) Determine whether the real-time temperature difference between the inlet and outlet of each heating water pipe meets the preset conditions for the inlet and outlet of the heating water pipe. Proceed to the next step only if it is determined to meet the conditions. 8) Determine whether the real-time temperature difference between the inlet and outlet of the adjacent heating water pipe meets the preset conditions for adjacent heating water pipes. Proceed to the next step only if it is determined to meet the conditions. 9) Sample the biogas residue sludge at the top of the heated drying bed at regular intervals. When the moisture content of the sampled sludge meets the preset threshold range, proceed to the next step. When the moisture content of the sampled sludge exceeds the preset threshold range, the control platform performs corresponding sludge drying control on the sludge drying zone. 10) The control platform uses a detection device to monitor sludge parameters and heating water pipe parameters during the sludge drying process in real time and sends them to the control platform. 11) The control platform corrects the preset sludge drying model based on the sludge parameters and heating water pipe parameters detected in real time during the sludge drying process. Its features are: In step 7), the real-time temperature of the inlet and outlet of each heating water pipe is detected and recorded. The system is considered to meet the preset inlet and outlet conditions of the heating water pipes only when the real-time temperature difference between the inlet and outlet of each heating water pipe is within the first preset threshold range; otherwise, If the real-time temperature difference between the inlet and outlet of at least one hot water pipe exceeds the first preset threshold range, it is determined that the preset conditions for the inlet and outlet of the hot water pipe are not met. In step 8), the real-time temperatures of the inlet and outlet of adjacent warm water pipes are detected and recorded respectively. The adjacent heating pipes are considered to meet the preset conditions only if the real-time temperature difference between the inlet and outlet of both adjacent heating pipes is within the second preset threshold range; otherwise, If the real-time temperature difference between the inlet or outlet of at least one adjacent heating water pipe exceeds the second preset threshold range, it is determined that the preset conditions for adjacent heating water pipes are not met. In step 9), When the sludge moisture content is higher than the preset threshold range, the control platform will implement corresponding sludge drying control in the sludge drying zone, including at least the following control methods: Control method A1: Increase the flow rate at the inlet and outlet of the heating water pipe; Control method A2: Increase the inlet temperature of the heating water pipe; Control method A3: Increase the sludge laying area; and Control method A4: Shorten the sludge renewal cycle; When the sludge moisture content is lower than the preset threshold range, the control platform performs corresponding sludge drying control in the sludge drying zone, including at least the following control methods: Control method B1: Reduce the flow rate at the inlet and outlet of the heating water pipe; Control method B2: Reduce the inlet temperature of the heating water pipe; Control method B3: Reduce the sludge laying area; and Control method B4: Extend the sludge renewal cycle; When the sludge moisture content is higher than the preset threshold range, the priority of the control methods is: control method A2 > control method A1 > control method A4 > control method A3. When the sludge moisture content is lower than the preset threshold range, the priority of the control mode is control mode B1 > control mode B4 > control mode B3 > control mode B2. The water tank in step 3) is equipped with a water tank temperature detection device and a water tank liquid level detection device, and a connection switch is provided between the water tank and the water pump. When the high-temperature water inside the water tank is higher than the preset liquid level and within the preset temperature range, the switch between the water tank and the water pump is opened to connect them. When the high-temperature water inside the tank is lower than the preset liquid level, the switch between the water tank and the water pump will be turned off; when the high-temperature water inside the tank exceeds the preset temperature range, the switch between the water tank and the water pump will be turned off, and the water tank temperature control device will be turned on to maintain the temperature inside the water tank within a suitable temperature range. In step 4), Select a preset sludge drying model in the control platform according to the sludge drying requirements; The initial parameters of the sludge include at least the type of sludge, the initial moisture content of the sludge, and the mass of the sludge. The sludge laying parameters include at least the sludge laying location and the footprint. The parameters for using the heating water pipes include at least the number of heating water pipes used, the number of water pumps used, and the initial output power.

2. The method for drying sludge using waste heat from carbon dioxide according to claim 1, characterized in that: In step 6), the floor space of the bedding layer is larger than the floor space of the top layer of biogas residue and sludge.

3. The method for drying sludge using waste heat from carbon dioxide according to claim 1, characterized in that: In step 9), when sampling and testing the biogas residue sludge at the top of the heated drying bed at each cycle time, it is necessary to simultaneously take several samples of the biogas residue sludge at both the outer edge and the inner edge of the bed, and the moisture content of the sampled sludge is the average value of the multiple sampling test results.

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