Bathing wastewater purification and heat exchange balance recycling method and system

Abstract

This invention discloses a method and system for purifying and recycling bath wastewater. The method includes: collecting bath wastewater and filtering it with solid waste to obtain filtered wastewater; subjecting the filtered wastewater to sterilization, grease decomposition, and pH adjustment to obtain purified wastewater; filtering the purified wastewater through a microfiltration unit and a reverse osmosis unit to obtain purified water and concentrated water; sending the purified water to a bath heating device and the concentrated water to a filtered wastewater purification unit for further purification and filtration; establishing a bath heat exchange cycle optimization model based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water; and adjusting the hot water temperature in the heating tank of the bath heating device in real time according to the model to maintain the bath water temperature within a set range during the bathing time and number of bathers. This invention achieves integrated purification and heat exchange recycling of bath wastewater.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, and more specifically, relates to a method and system for purifying and recycling bath wastewater in a balanced heat exchange manner. Background Technology

[0002] Bathing wastewater is a type of relatively lightly polluted domestic wastewater, characterized by its large volume (approximately 30% in residential areas and 70% in hotels and restaurants), ease of separation, and convenient collection. The pollutants in bathing wastewater originate from two sources: firstly, secretions from the skin, primarily including substances such as potassium, sodium, chloride, urea, uric acid, creatinine, and lactic acid in sweat, and fatty acids, cholesterol, protein exudate, and sebaceous gland cell debris in sebum; secondly, detergents used during bathing. Currently, most bathing water is directly discharged after single use, which not only increases the burden on urban drainage and water treatment systems but also wastes precious water resources. If it could be collected, treated, and reused comprehensively, it would not only provide a large amount of raw water but also reduce the difficulty and cost of treatment, creating significant economic, environmental, and social benefits.

[0003] The process and related equipment are simple and easy to operate and manage, making it very suitable for the reuse of wastewater in hotels. However, this process filters and separates bathing wastewater, with a portion reused for hotel toilet flushing and landscaping, while the remaining ultrafiltration effluent is further treated by nanofiltration membrane devices and disinfection before being reused for hotel laundry and bathing. On the one hand, this method fails to fully utilize the waste heat exchange of bathing wastewater to quickly heat the water for bathing, resulting in problems such as time-consuming and energy-intensive heating. On the other hand, this method does not consider the problem of uneven water temperature when multiple people are bathing at the same time. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a method and system for controlling the purification and recycling of bathing wastewater. An optimization model for heat exchange circulation in bathing is established based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water. This model is used to adjust the temperature of the hot water in the inner tank of the bathing heating equipment in real time, ensuring that the temperature of the bathing water used by the number of bathers during the bathing time remains within a set range, thus achieving the integration of bathing wastewater purification and heat exchange recycling.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a method for purifying and recycling bath wastewater in a balanced heat exchange manner is provided, comprising the following steps:

[0006] S100: After the bathing wastewater is collected, the wastewater and solid waste are filtered to obtain filtered wastewater. The filtered wastewater is then subjected to sterilization, grease decomposition and pH adjustment to obtain purified wastewater.

[0007] S200: After the purified wastewater is filtered by the microfiltration and reverse osmosis components, it becomes purified water and concentrated water. The purified water is sent to the bath heating equipment, and the concentrated water is sent to the wastewater purification unit for further purification and filtration.

[0008] S300: Establish a bathing heat exchange circulation optimization model based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water. Adjust the temperature of the hot water in the heating tank of the bathing heating equipment in real time according to the model so that the temperature of the bathing water used by the number of bathers during the bathing time is kept within the bathing set range.

[0009] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0010] S301: Based on the actual conditions of the bathing scenario, dynamically predict the total heat demand of multiple people bathing simultaneously. for:

[0011]

[0012] in: Water flow rate Let t represent the number of people showering at time t, and let represent the water load. This represents the average shower time per person. It is the specific heat capacity of water. These are the target outlet water temperature and the cold water inlet temperature, respectively, representing the temperature of the unheated cold water before it enters the heating system or heat exchanger. This indicates the amount of heat used by a single person.

[0013] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0014] S302: During the wastewater purification process, solid impurities and chemical pollutants are separated through sedimentation, filtration, and sterilization, and the heat from the wastewater is recovered in real time. for:

[0015]

[0016] in: This indicates the quality of wastewater. The density of water, The wastewater temperature is indicated by the temperature of the user's discharge. Indicates ambient temperature.

[0017] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0018] S303: The latent heat and sensible heat of the steam generated during bathing are recovered through a condensation device, which are respectively:

[0019] in: To recover heat from steam, To recover heat from the sensible heat of condensate, L represents the mass of steam, and L represents the latent heat of vaporization of steam. This represents the temperature of the condensate.

[0020] Thus, the total waste heat recovery amount is:

[0021] .

[0022] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0023] S304: Based on the total heat demand of multiple people showering simultaneously and the total waste heat recovery, a dynamic optimization model for the heat exchanger is established as follows:

[0024]

[0025] in: To be allocated to the i The input heat of a heat exchanger; To be allocated to the i The heat of wastewater from the heat exchanger To be allocated to the i The steam heat of the heat exchanger To be allocated to the i The sensible heat capacity of each heat exchanger, and the output heat capacity are: , For heat exchanger efficiency, the heat exchanger load balancing is as follows:

[0026]

[0027] in: The threshold for limiting the fluctuation of heat output from the heat exchanger.

[0028] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0029] S305: Total supplemental calories are: Based on replenishing calories The heat allocated to each heat exchanger is as follows: The predicted outlet water temperature after heating is: Therefore, the error between the actual water temperature and the target temperature is: .

[0030] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0031] The output power of the bath heating equipment is obtained by implementing PID control to achieve heat exchange balance circulation of bath wastewater. for:

[0032]

[0033] in: This represents the proportional gain coefficient of the PID controller. This represents the integral gain coefficient of the PID controller. This represents the differential gain coefficient of the PID controller.

[0034] According to a second aspect of the present invention, a bathing wastewater purification and heat exchange balance recycling system is provided, for implementing the aforementioned bathing wastewater purification and heat exchange balance recycling method, comprising:

[0035] The primary purification module for bath wastewater is used to collect bath wastewater and filter it with solid waste to obtain filtered wastewater. After sterilization, grease decomposition and pH adjustment of the filtered wastewater, purified wastewater is obtained.

[0036] The deep purification module for bath wastewater is used to filter purified wastewater through microfiltration and reverse osmosis components to obtain purified water and concentrated water. The purified water is sent to the bath heating equipment, and the concentrated water is sent to the wastewater purification unit for further purification and filtration.

[0037] The heat exchange balance recycling module is used to establish a heat exchange cycle optimization model for bathing based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water. Based on this model, the hot water temperature in the inner tank of the bathing heating equipment is adjusted in real time so that the temperature of the bathing water used by the number of bathers during the bathing time is kept within the set bathing range.

[0038] Furthermore, the bathing heating equipment includes: a constant temperature water tank, an inner heat exchange tube, an outer heat exchange tube, and a heating element; wherein,

[0039] The constant temperature water tank is equipped with a heating inner tank, and a heating element for heating the purified water is installed in the heating inner tank.

[0040] The constant temperature water tank is equipped with an inner heat exchange tube. The inlet of the inner heat exchange tube is connected to a water purification pump. The water purification pump is used to send purified water, which is produced by re-filtration of purified wastewater, into the inner heat exchange tube. The outlet of the inner heat exchange tube is connected to the inlet of the heat exchange outer tube.

[0041] The inlet of the heating inner tank of the constant temperature water tank is connected to the inlet pipe, and the outlet of the heating inner tank is connected to the drain pipe; the constant temperature water tank is equipped with multiple temperature sensors for detecting temperature, and is also equipped with a pressure relief valve for adjusting the pressure of the heating inner tank and a level gauge for measuring the liquid level in the heating inner tank.

[0042] Furthermore, the heat exchange outer tube is wound around the periphery of the constant temperature water tank, and the outlet of the heat exchange outer tube is used to output bathing water.

[0043] The outer layer of cold water in the heat exchange outer tube absorbs heat from the inner layer of water, thus raising the temperature of the cold water. The initial temperature of the cold water is increased before it flows into the constant temperature water tank to heat the inner liner.

[0044] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0045] 1. The method of the present invention establishes a bathing heat exchange circulation optimization model based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water. Based on the model, the temperature of the hot water in the heating tank of the bathing heating equipment is adjusted in real time, so that the temperature of the bathing water used by the number of bathers during the bathing time is kept within the bathing set range, thereby realizing the integration of bathing wastewater purification and heat exchange circulation.

[0046] 2. The method of the present invention involves collecting bath wastewater, filtering the wastewater and solid waste to obtain filtered wastewater, subjecting the filtered wastewater to sterilization, grease decomposition, and pH adjustment to obtain purified wastewater, and then filtering the purified wastewater through a microfiltration unit and a reverse osmosis unit to obtain clean water and concentrated water. The clean water is sent to the bath heating equipment, and the concentrated water is sent to the filtered wastewater purification unit for further purification and filtration, thus achieving multi-stage purification treatment of bath wastewater.

[0047] 3. In the wastewater purification process of the present invention, after separating solid impurities and chemical pollutants through sedimentation, filtration and sterilization, the heat of the wastewater is recovered in real time. The heat exchange balance circulation control of the bath wastewater is realized through PID, the output power of the bath heating equipment is obtained, and the temperature of the hot water in the heating tank of the bath heating equipment is adjusted in real time. Attached Figure Description

[0048] Figure 1 This is a flowchart illustrating the bathing process of the bathing wastewater purification and recycling method according to an embodiment of the present invention.

[0049] Figure 2 This is a schematic diagram of the system composition of the bathing wastewater purification and recycling method according to an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the structure of the bathing heating equipment in the bathing wastewater purification and recycling method of this invention.

[0051] Figure 4 This is a graph showing the relationship between the temperature of the heated inner tank center and time, according to an embodiment of the present invention.

[0052] Figure 5 This is a graph showing the relationship between the water temperature at the start of a single-person bath and the number of bathers in an embodiment of the present invention.

[0053] Figure 6 This is a graph showing the relationship between the water temperature at the end of a single person's bath and the number of people bathing, according to an embodiment of the present invention.

[0054] Figure 7 This is a graph showing the relationship between the water temperature difference and the number of bathers during a single-person bathing process according to an embodiment of the present invention.

[0055] Figure 8 This is a graph showing the relationship between the water temperature at the start of a multi-person bathing session and the number of bathers, according to an embodiment of the present invention.

[0056] Figure 9 This is a graph showing the relationship between the water temperature at the end of a multi-person bathing session and the number of bathers, according to an embodiment of the present invention.

[0057] Figure 10 This is a graph showing the relationship between the water temperature difference and the number of bathers during a multi-person bathing process according to an embodiment of the present invention.

[0058] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. constant temperature water tank; 2. internal heat exchange tube; 3. 003; 4. level gauge; 5. pressure relief valve; 8. temperature sensor; 9. heating element; 10. water inlet pipe; 11. drain pipe; 12. heat exchange outer pipe. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0060] Example 1

[0061] Reference Figure 1 This invention provides a method for controlling the purification and recycling of bathing wastewater, comprising the following steps:

[0062] S100: After the bathing wastewater is collected, the wastewater and solid waste are filtered to obtain filtered wastewater. The filtered wastewater is then subjected to sterilization, grease decomposition and pH adjustment to obtain purified wastewater.

[0063] S200: After the purified wastewater is filtered by the microfiltration and reverse osmosis components, it becomes purified water and concentrated water. The purified water is sent to the bath heating equipment, and the concentrated water is sent to the wastewater purification unit for further purification and filtration.

[0064] In this embodiment, the wastewater collection method further includes the following steps: filtering wastewater and solid waste through a hair filter, and filtering wastewater and grease and large particulate impurities through a carbon fiber filter to obtain filtered wastewater, and sending the filtered wastewater to a wastewater collection tank.

[0065] In this embodiment, the method for purifying filtered wastewater further includes the following steps: sterilizing the filtered wastewater in the wastewater collection tank using an ozone generator and decomposing residual grease; and sending pH adjusting agent from the dosing tank to the wastewater collection tank using a dosing pump to adjust the pH value of the filtered wastewater in the wastewater collection tank to the set pH value.

[0066] In this embodiment, the pH adjusting agent is oxalic acid, citric acid, or dilute hydrochloric acid with a pH value of 1.

[0067] In this embodiment, the wastewater purification and refiltration method further includes the following steps: when the water level in the wastewater collection tank reaches the high level of the wastewater collection tank, and the water level in the clean water tank is lower than the high level of the clean water tank, the wastewater treatment pump sends the filtered wastewater in the wastewater collection tank to the microfiltration component and the reverse osmosis component for filtration treatment in sequence. The clean water discharged from the reverse osmosis component is sent to the clean water tank, which supplies water to the bathing heating equipment. The concentrated water discharged from the reverse osmosis component is sent to the wastewater collection tank.

[0068] It is necessary to clarify that the microfiltration component is a microfiltration processor, and the reverse osmosis component is a reverse osmosis processor.

[0069] In this embodiment, the wastewater purification re-filtration method further includes the following steps: when the amount of filtered wastewater in the wastewater collection tank reaches the low water level of the wastewater collection tank, and the water level in the clean water tank reaches the high liquid level of the clean water tank, the wastewater treatment pump stops working, completing a single wastewater purification re-filtration step.

[0070] Preferably, in this embodiment, before the wastewater treatment pump sequentially sends the filtered wastewater from the wastewater collection tank to the microfiltration module and the reverse osmosis module for filtration, the backwashing solenoid valve is opened first, so that the filtered wastewater first passes through the microfiltration module and the reverse osmosis module to perform backwashing. The flushing water generated during the backwashing is sent to the sewage drain pipe; until the backwashing time reaches the backwashing duration.

[0071] In this embodiment, the method for planning the heating of bath water further includes the following steps: setting low, medium and high liquid levels in the purified water tank; when the water level in the purified water tank is lower than the low liquid level, the water replenishment solenoid valve is opened, and sanitary water is replenished into the purified water tank until the water level in the purified water tank reaches the medium liquid level, after which water replenishment is stopped; after water replenishment is completed, the temperature of the hot water in the inner tank of the bath heating equipment is determined; and the water in the purified water tank is sterilized by ultraviolet sterilization lamp.

[0072] This invention also provides a control method for the purification and recycling of bathing wastewater, applied to the method of purifying and recycling bathing wastewater, the method comprising the following steps:

[0073] When the pH meter detects that the pH value of the filtered wastewater is >9, the pH dosing pump is started so that the pH adjusting agent adjusts the pH value of the filtered wastewater to ≤8.

[0074] Wastewater collection: After collecting the bathing wastewater, filter the wastewater and solid waste to obtain filtered wastewater;

[0075] Wastewater purification: After sterilization, grease decomposition and pH adjustment of the filtered wastewater, purified wastewater is obtained.

[0076] After the purified wastewater is filtered through the microfiltration and reverse osmosis components, the filtered water is obtained. When the turbidity of the filtered water is ≤1 NTU, the filtered water is determined to be clean water and is sent to the bathing and heating equipment. When the turbidity of the filtered water is >1 NTU, the filtered water is determined to be concentrated water and is sent to the wastewater purification step for further purification and filtration.

[0077] S300: Establish a bathing heat exchange circulation optimization model based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water. Adjust the temperature of the hot water in the heating tank of the bathing heating equipment in real time according to the model so that the temperature of the bathing water used by the number of bathers during the bathing time is kept within the bathing set range.

[0078] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0079] S301: Based on the actual conditions of the bathing scenario, dynamically predict the total heat demand of multiple people bathing simultaneously. for:

[0080]

[0081] in: Water flow rate Let t represent the number of people showering at time t, and let represent the water load. This represents the average shower time per person. It is the specific heat capacity of water. These are the target outlet water temperature and the cold water inlet temperature, respectively, representing the temperature of the unheated cold water before it enters the heating system or heat exchanger. This indicates the amount of heat used by a single person.

[0082] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0083] S302: During the wastewater purification process, solid impurities and chemical pollutants are separated through sedimentation, filtration, and sterilization, and the heat from the wastewater is recovered in real time. for:

[0084]

[0085] in: This indicates the quality of wastewater. The wastewater temperature is indicated by the temperature of the user's discharge. Indicates ambient temperature.

[0086] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0087] S303: The latent heat and sensible heat of the steam generated during bathing are recovered through a condensation device, which are respectively:

[0088] in: To recover heat from steam, To recover heat from the sensible heat of condensate, L represents the mass of steam, and L represents the latent heat of vaporization of steam. This represents the temperature of the condensate.

[0089] Thus, the total waste heat recovery amount is: .

[0090] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0091] S304: Based on the total heat demand of multiple people showering simultaneously and the total waste heat recovery, a dynamic optimization model for the heat exchanger is established as follows:

[0092]

[0093] in: To be allocated to the i The input heat of a heat exchanger; To be allocated to the i The heat of wastewater from the heat exchanger To be allocated to the i The steam heat of the heat exchanger To be allocated to the i The sensible heat capacity of each heat exchanger, and the output heat capacity are: , For heat exchanger efficiency, the heat exchanger load balancing is as follows:

[0094]

[0095] in: The threshold for limiting the fluctuation of heat output from the heat exchanger.

[0096] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0097] S305: Total supplemental calories are: Based on replenishing calories The heat allocated to each heat exchanger is as follows: The predicted outlet water temperature after heating is: Therefore, the error between the actual water temperature and the target temperature is: .

[0098] Furthermore, the step S300 of establishing the bath heat exchange cycle optimization model includes:

[0099] The output power of the bath heating equipment is obtained by implementing PID control to achieve heat exchange balance circulation of bath wastewater. for:

[0100]

[0101] in: This represents the proportional gain coefficient of the PID controller. This represents the integral gain coefficient of the PID controller. This represents the differential gain coefficient of the PID controller.

[0102] Example 2

[0103] Such as 2 and Figure 3 As shown, in this embodiment, a bathing wastewater purification and heat exchange balance recycling system is provided to implement the aforementioned bathing wastewater purification and heat exchange balance recycling method, comprising:

[0104] The primary purification module for bath wastewater is used to collect bath wastewater and filter it with solid waste to obtain filtered wastewater. After sterilization, grease decomposition and pH adjustment of the filtered wastewater, purified wastewater is obtained.

[0105] The deep purification module for bath wastewater is used to filter purified wastewater through microfiltration and reverse osmosis components to obtain purified water and concentrated water. The purified water is sent to the bath heating equipment, and the concentrated water is sent to the wastewater purification unit for further purification and filtration.

[0106] The heat exchange balance recycling module is used to establish a heat exchange cycle optimization model for bathing based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water. Based on this model, the hot water temperature in the inner tank of the bathing heating equipment is adjusted in real time so that the temperature of the bathing water used by the number of bathers during the bathing time is kept within the set bathing range.

[0107] The bathing heating equipment includes a constant temperature water tank 1, an inner heat exchange tube 2, a heat exchange outer tube 12, and a heating tube 9. The heating inner tank of the constant temperature water tank 1 is equipped with a heating tube 9 for heating the purified water in the inner tank. The constant temperature water tank 1 is also equipped with an inner heat exchange tube 2. The inlet of the inner heat exchange tube 2 is connected to a water purification pump. The water purification pump is used to send the purified water produced by the re-filtration of purified wastewater to the inner heat exchange tube 2. The outlet of the inner heat exchange tube 2 is connected to the inlet of the heat exchange outer tube 12. The heat exchange outer tube 12 is arranged around the periphery of the constant temperature water tank 1, and the outlet of the heat exchange outer tube 12 delivers bathing water.

[0108] The inlet of the heating inner tank of the constant temperature water tank 1 is connected to the inlet pipe 10, and the outlet of the heating inner tank is connected to the drain pipe 11. Multiple temperature sensors 8 are also installed in the heating inner tank for temperature detection. The constant temperature water tank 1 is equipped with a pressure relief valve 5 for regulating the pressure of the heating inner tank, and a level gauge 4 for measuring the liquid level in the heating inner tank. The inner and outer layers of water in the outer pipe are connected in one path within the inner tank. The temperature absorbed by the cold water in the outer pipe increases the initial temperature heated by the inner tank; simultaneously, the heat absorbed by the outer water from the inner water also prevents the shower water temperature from becoming too hot, maintaining it at around 40 degrees Celsius, thus preventing scalding.

[0109] Example 3

[0110] like Figure 8-10 As shown, in this embodiment, a bathing heat exchange cycle optimization model was used to simulate the bathing process of 20 people, setting the bathing time for each person to be 10 minutes and the interval between two people to be 5 minutes. During the bathing process, the heat exchange cycle is optimized by... Figure 4 As can be seen, after cold water enters the heat exchange outer tube 12, it absorbs the heat from the counter-flowing hot water in the inner layer, gradually raising its temperature to 46°C before entering the inner heat exchange tube 2 in the constant temperature water tank 1. The coils flowing down the inner heat exchange tube 2 absorb heat from the water in the constant temperature water tank 1, raising its temperature to approximately 73°C. The coils then flow up the inner heat exchange tube 2, maintaining the temperature at 73°C, to the inner layer of the heat exchange outer tube 12. During the counter-flow of hot water in the inner layer of the heat exchange outer tube 12 and cold water in the outer layer, the hot water gradually transfers its temperature to the cold water in the outer layer, raising its temperature to 42°C. This ensures that the bathing water is at approximately 42°C. This is achieved through the counter-flow heat exchange of the sleeve and the heat exchange structure of the inner tank.

[0111] Depend on Figure 4As can be seen, the water temperature at the center of the tank rapidly dropped from 85℃ to 71℃ within t=0~3min. This is related to the initial simulation conditions. The calculation was set so that at t=0min, the water temperature in the pipes was 20℃ and the water temperature in the tank was 85℃, resulting in a large heat flow and thus a sudden temperature drop. From t=3min onwards, the temperature at the center of the tank exhibited a 15-minute cycle. Corresponding to the water flow switch status in the pipes, during a single person's shower, the temperature inside the tank gradually decreased when the water in the pipes was flowing, with an average decrease of approximately 2.32℃. During the interval after the shower ended, when the water in the pipes was not flowing, the temperature inside the tank gradually rose again, with an average increase of approximately 2.26℃. The water temperature inside the tank was 69.84℃ after the 20th person finished showering.

[0112] Depend on Figure 5 The data shows that the water temperature at the start of the bath for the first person was 43.28℃, for the 20th person it was 42.47℃, and the average starting water temperature for all 20 people was 42.65℃. The starting water temperature gradually decreased as more people bathed, with the rate of decrease decreasing, the maximum decrease being 0.38℃ and the minimum being 0℃.

[0113] Depend on Figure 6 The data shows that the water temperature at the end of the bath for the first person was 41.82℃, and for the 20th person it was 41.31℃. The average starting temperature for all 20 people was 41.48℃. The water temperature at the end of the bath gradually decreased with the number of people bathing, with a maximum drop of 0.08℃ and a minimum drop of 0℃. Figure 8 This indicates the change in water temperature as the number of people showering during a single shower. Figure 8 It can be seen that, except for the first person whose water temperature difference was 1.46℃ during the 10-minute shower, the average water temperature difference for the remaining 19 people was 1.15℃, indicating that the water temperature was relatively stable during the shower.

[0114] After entering from the outer layer of the external heat exchange sleeve, the cold water absorbs the heat from the counter-flowing hot water in the inner layer and gradually rises to 46°C before entering the inner heat exchange coil in the inner tank. The downward-flowing coil absorbs heat from the water in the inner tank to about 73°C, and then flows along the upward-flowing coil at 73°C to the inner layer of the external heat exchange sleeve. During the counter-flow with the cold water in the outer layer, the cold water gradually transfers its temperature to the cold water, and finally reaches the outlet at a temperature of about 42°C.

[0115] In summary, when the heating element 9 heats and stabilizes the water temperature in the constant temperature water tank 1 at 69.8℃~73.3℃, ​​the water temperature exiting the pipes can remain stable at 41.3℃~43.4℃ throughout the entire showering process for 20 people. The water temperature is comfortable, eliminating the need to adjust the mixing valve and avoiding scalding caused by improper mixing. Furthermore, the temperature fluctuation for a single person is minimal, approximately 1.15℃, thus providing a better showering experience.

[0116] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bathing wastewater purification and heat exchange balance recycling system, characterized in that, include: The primary purification module for bath wastewater is used to collect bath wastewater and filter it with solid waste to obtain filtered wastewater. After sterilization, grease decomposition and pH adjustment of the filtered wastewater, purified wastewater is obtained. The deep purification module for bath wastewater is used to filter purified wastewater through microfiltration and reverse osmosis components to obtain purified water and concentrated water. The purified water is sent to the bath heating equipment, and the concentrated water is sent to the wastewater purification unit for further purification and filtration. The heat exchange balance recycling module is used to establish a heat exchange cycle optimization model for bathing based on the number of bathers, bathing time, bathing flow rate and the real-time temperature of the purified water. Based on the model, the hot water temperature in the heating tank of the bathing heating equipment is adjusted in real time so that the bathing water temperature used by the number of bathers during the bathing time is kept within the bathing set range. The bathing heating equipment includes: a constant temperature water tank (1), an inner heat exchange tube (2), an outer heat exchange tube (12), and a heating element (9); wherein, The constant temperature water tank (1) is equipped with a heating inner tank, and a heating tube (9) for heating the purified water is installed in the heating inner tank. The constant temperature water tank (1) is equipped with an inner heat exchange tube (2). The inlet of the inner heat exchange tube (2) is connected to a water purification pump. The water purification pump is used to send the purified wastewater, which is then filtered again, into the inner heat exchange tube (2). The outlet of the inner heat exchange tube (2) is connected to the inlet of the heat exchange outer tube (12). The inlet of the heating inner tank of the constant temperature water tank (1) is connected to the inlet pipe (10), and the outlet of the heating inner tank is connected to the drain pipe (11). The constant temperature water tank (1) is equipped with multiple temperature sensors (8) for detecting temperature, and is provided with a pressure relief valve (5) for adjusting the pressure of the heating inner tank and a level gauge (4) for measuring the liquid level in the heating inner tank. The heat exchange outer pipe (12) is wrapped around the periphery of the constant temperature water tank (1), and the outlet of the heat exchange outer pipe (12) is used to output bath water; The outer layer of cold water in the heat exchange outer tube (12) increases its temperature by absorbing heat from the inner layer of water, thus raising the initial temperature of the cold water before it flows into the constant temperature water tank (1) to heat the inner liner.

2. A method for purifying and recycling bath wastewater through heat exchange equilibrium, characterized in that, The system for purifying and recycling bath wastewater as described in claim 1 includes the following steps: S100: After the bathing wastewater is collected, the wastewater and solid waste are filtered to obtain filtered wastewater. The filtered wastewater is then subjected to sterilization, grease decomposition and pH adjustment to obtain purified wastewater. S200: After the purified wastewater is filtered by the microfiltration and reverse osmosis components, it becomes purified water and concentrated water. The purified water is sent to the bath heating equipment, and the concentrated water is sent to the wastewater purification unit for further purification and filtration. S300: Establish a bathing heat exchange cycle optimization model based on the number of bathers, bathing time, bathing flow rate, and the real-time temperature of the purified water. Adjust the temperature of the hot water in the inner tank of the bathing heating equipment in real time according to the model so that the temperature of the bathing water used by the number of bathers during the bathing time is kept within the set bathing range.

3. The method for purifying and recycling bath wastewater according to claim 2, characterized in that, Step S300, which establishes the optimization model for the bathing heat exchange cycle, includes: S301: Based on the actual situation of the bathing scenario, the total heat demand for multiple people bathing simultaneously is dynamically predicted as follows: ， in: Water flow rate The number of people showering at any given time indicates the water load. This represents the average shower time per person. It is the specific heat capacity of water. These are the target outlet water temperature and the cold water inlet temperature, respectively, representing the temperature of the unheated cold water before it enters the heating system or heat exchanger. This indicates the amount of heat used by a single person.

4. The method for purifying and recycling bath wastewater according to claim 3, characterized in that, Step S300, which establishes the optimization model for the bathing heat exchange cycle, includes: S302: During the wastewater purification process, solid impurities and chemical pollutants are separated through sedimentation, filtration, and sterilization, and the heat from the wastewater is recovered in real time. for: ， in: This indicates the quality of the wastewater. The wastewater temperature is indicated by the temperature of the user's discharge. Indicates ambient temperature. It is the specific heat capacity of water. This is the density of water.

5. The method for purifying and recycling bath wastewater according to claim 4, characterized in that, Step S300, which establishes the optimization model for the bathing heat exchange cycle, includes: S303: The latent heat and sensible heat of the steam generated during bathing are recovered through a condensation device, which are respectively: ， ， in: To recover heat from steam, To recover heat from the sensible heat of condensate, Represents the quality of steam. The latent heat of vaporization of steam This refers to the inlet temperature of the cold water. Indicates ambient temperature. It is the specific heat capacity of water; Thus, the total waste heat recovery amount is: .

6. The method for purifying and recycling bath wastewater according to claim 5, characterized in that, Step S300, which establishes the optimization model for the bathing heat exchange cycle, includes: S304: Based on the total heat demand of multiple people showering simultaneously and the total waste heat recovery, a dynamic optimization model for the heat exchanger is established as follows: ， in: Q represents the input heat allocated to the i-th heat exchanger. i,out The output heat of the i-th heat exchanger; To allocate the wastewater heat to the i-th heat exchanger, To allocate steam heat to the i-th heat exchanger, The sensible heat allocated to the i-th heat exchanger is: , For heat exchanger efficiency, the heat exchanger load balancing is as follows: ， in: To limit the threshold for fluctuations in the output heat of the heat exchanger, Q j,out Let be the output heat of the j-th heat exchanger.

7. The method for purifying and recycling bath wastewater according to claim 6, characterized in that, Step S300, which establishes the optimization model for the bathing heat exchange cycle, includes: S305: Total supplemental calories are: Based on replenishing calories The heat allocated to each heat exchanger is as follows: The predicted outlet water temperature after heating is: , To predict the outlet water temperature after heating, This refers to the inlet temperature of the cold water. This represents the mass flow rate of the heated cold water, thus the error between the actual water temperature and the target temperature is: , The target outlet water temperature.

8. The method for purifying and recycling bath wastewater according to claim 7, characterized in that, Step S300, which establishes the optimization model for the bathing heat exchange cycle, includes: The output power of the bath heating equipment is obtained by implementing PID control to achieve heat exchange balance circulation of bath wastewater. for: ， in: This represents the proportional gain coefficient of the PID controller. This represents the integral gain coefficient of the PID controller. This represents the derivative gain coefficient of the PID controller.

Images