A domestic wastewater recycling system capable of recovering heat energy

Abstract

The present invention relates to the field of wastewater heat recovery technology, and in particular to a domestic wastewater recycling system capable of heat recovery, comprising a PVT module, a main heat storage tank, a secondary heat storage tank, an indoor heating module, a power distribution module and a heat recovery control module, wherein the PVT module delivers hot water and electric energy to the main heat storage tank and the secondary heat storage tank, the indoor heating module is used to absorb the heat of hot water and convert it into air heat, the heat recovery control module is used to perform heat exchange between domestic hot wastewater discharged by users and tap water, and the power distribution module is used to distribute electric energy to each user according to the user's daily power demand and the electric energy produced by the PVT module, so as to minimize the total city electricity consumption. The present invention optimizes the distribution method of the hot wastewater recovery cycle by predicting the user's daily hot water consumption and the electric energy and hot water produced by the PVT module daily, and reasonably distributes hot water and electric energy to users, thereby effectively improving the utilization rate of the PVT module and reducing the overall hot water use cost.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater heat energy recovery, and in particular to a domestic wastewater recycling system capable of recovering heat energy. Background Art

[0002] The domestic wastewater recycling system based on heat recovery is a system that recovers heat energy from domestic wastewater and utilizes it. This system usually includes wastewater utilization devices, water storage tanks, pumping stations and other equipment, and is suitable for domestic wastewater reuse in residential areas and hotels. The domestic wastewater recycling system can not only effectively utilize resources, reduce energy consumption and environmental pollution, but also bring significant economic benefits.

[0003] However, the existing domestic wastewater recycling system also has some defects: lack of real-time and effective monitoring and control strategies. Most of the existing domestic wastewater recycling systems directly exchange the hot wastewater generated in life. This method has high practical value in an independent water circulation system, but there is a waste of heat energy in the PVT module water circulation system composed of multiple users. In addition to the reasonable allocation among multiple users, the existing domestic wastewater recycling system also lacks analysis of users' water use habits and prediction of water consumption. Therefore, in the actual hot water distribution and heat recovery distribution, it is difficult to achieve higher utilization efficiency, which increases the overall cost of hot water use.

[0004] In general, the existing domestic wastewater recycling system has significant advantages in terms of individual energy conservation, emission reduction and environmental protection, but its application in the implementation of collective water recycling still needs to overcome technical and economic challenges. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a domestic wastewater recycling system capable of recovering heat energy.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: a domestic wastewater recycling system capable of recovering heat energy, comprising: a PVT module, a primary heat storage tank, a secondary heat storage tank, an indoor heating module, a hot water circulation module, a power distribution module and a heat recovery control module.

[0007] The PVT module is used to absorb solar energy and convert it into electrical energy and thermal energy. The main heat storage tank is connected to the PVT module. The secondary heat storage tank is connected to the main heat storage tank and the PVT module respectively. The indoor heating module includes an electric boiler and a radiator. The electric boiler is installed in the user's room and is connected to the main heat storage tank and the secondary heat storage tank respectively. The radiator is installed in the user's room to absorb the heat of the hot water in the electric boiler and convert it into air heat. The heat recovery control module is used to exchange the domestic hot waste water discharged by the user with tap water. The hot water circulation module is used to control the water transportation status and transportation direction between modules. The power distribution module is used to distribute electricity to each user according to the user's daily electricity demand and the electricity produced by the PVT module, so as to minimize the total city electricity consumption.

[0008] As a preferred technical solution of the present invention, the PVT module includes a solar photovoltaic unit and a photothermal unit, wherein the photovoltaic unit is used to convert solar energy into electrical energy, and the photothermal unit is used to heat tap water.

[0009] As a preferred technical solution of the present invention, heating wires are installed in both the primary heat storage tank and the secondary heat storage tank, and the heating wires are electrically connected to the photovoltaic unit.

[0010] As a preferred technical solution of the present invention, the hot water circulation module includes multiple pipes, solenoid valves, filters and pressure switches. The multiple pipes are used to connect the PVT module, the main heat storage tank, the secondary heat storage tank, the indoor heating module, the user's domestic water module and the tap water system, and form a circulation connection between the modules. The solenoid valves are respectively installed on the pipes to control the connection state of the pipes. The filter is installed on the pipe to filter impurities in the pipe water. The pressure switch is installed on the pipe to control the water flow rate in the pipe.

[0011] As a preferred technical solution of the present invention, the heat recovery control module includes a hot wastewater monitoring unit, a hot wastewater prediction unit and a heat exchange distribution unit. The hot wastewater monitoring unit is used to monitor the temperature and flow of hot wastewater discharged by users in real time, and separate the hot wastewater discharged by users from cold wastewater. The hot wastewater prediction unit is used to predict the discharge volume and average temperature of hot wastewater in the next period of time according to the hot water status used by users and the current hot water temperature. The heat exchange distribution unit is used to calculate the heat exchange amount required by each user according to the amount of hot water required by each user, the current amount of hot water and the comprehensive amount of hot wastewater, and then distribute the hot wastewater discharged by each user in proportion to minimize the comprehensive hot water demand.

[0012] As a preferred technical solution of the present invention, the method for predicting the discharge volume and average temperature of the hot wastewater from bathing by the hot wastewater monitoring unit is as follows:

[0013] Get the number of people bathing in each user's household on that day.

[0014] Analyze each person's bathing time, water consumption, and bathing temperature based on the bathing water history records of each user's family: Establish a bathing prediction model based on machine learning, extract user characteristics, environmental characteristics, and date characteristics from the bathing water history data, and use these characteristics as input, and use bathing time, water consumption, and bathing temperature as output to train the bathing prediction model and retain the model parameters that meet the test accuracy. Extract the corresponding current user characteristics, current environmental characteristics, and current date characteristics based on the current user data, environmental data, and date data, and input them into the trained bathing prediction model to obtain the corresponding predicted bathing time t b , predicted water consumption V b , predict bath temperature T b .

[0015] Query the heat loss rate η according to the ambient temperature b and hot water evaporation rate η e , and then combined with the predicted bathing time, water consumption and bathing temperature, the total daily discharge volume and average temperature of bathing hot wastewater are calculated.

[0016] The total amount of hot wastewater discharged from bathing every day is V hp Expressed as:

[0017] V hp =V b (1-η e )

[0018] Where V b To predict water consumption, η e is the hot water evaporation rate.

[0019] Average temperature of hot wastewater T hp Expressed as:

[0020] T hp =T b -η b (t b -1) / 2

[0021] Where, T b To predict the bath temperature, t b To predict the bathing time, η b is the heat loss rate.

[0022] As a preferred technical solution of the present invention, the power distribution module includes a user hot water demand prediction unit, a PVT output prediction unit, a power distribution unit and a power real-time correction unit. The user hot water demand prediction unit is used to calculate the user's hot water demand based on the user's current hot water inventory and the predicted amount of hot water required by the user. The PVT output prediction unit is used to predict the amount of electricity and hot water produced by the PVT module on the day based on environmental parameters. The power distribution unit is used to distribute the electricity produced by the PVT module to the main heat storage tank and each secondary heat storage tank based on the predicted PVT module output electricity, output hot water and user hot water demand, and calculate the additional electricity required by each user. The power real-time correction unit is used to make real-time corrections to the power distribution module based on the actual amount of hot water used by the user.

[0023] As a preferred technical solution of the present invention, in the user hot water demand prediction unit, the user hot water demand V L Expressed as:

[0024] V L =V n -V si -V hc

[0025] Where V n is the amount of hot water required by the user, V si is the current water storage capacity, V hc The equivalent amount of hot water for heat exchange is expressed as:

[0026] V hc =η c V hp (T hp -T5) / T i

[0027] Where η c is the heat exchange efficiency, V hp is the total daily discharge of hot wastewater from bathing, T hp is the average temperature of hot wastewater, T5 is the cold water temperature, T i The temperature of hot water for heating.

[0028] As a preferred technical solution of the present invention, the specific prediction steps of the PVT output prediction unit are as follows:

[0029] Build a deep learning-based lighting prediction model.

[0030] Collect historical environmental data and perform preprocessing.

[0031] The preprocessed historical environmental data is subjected to feature extraction to obtain basic meteorological features and date features.

[0032] The historical environmental data are divided into a training set and a test set according to a preset ratio. The training set is used to train the lighting prediction model, and the test set is used to verify it until the test accuracy meets the preset accuracy and the corresponding model parameters are retained.

[0033] Input recent environmental data into the lighting prediction model to obtain predicted lighting data.

[0034] The predicted output power W is calculated based on the light data and the conversion efficiency of the PVT module. p And hot water volume Q p .

[0035] As a preferred technical solution of the present invention, the distribution strategy of the power distribution unit is:

[0036] a. If W p +W pc ≥W n , then the electricity produced by PVT is distributed in proportion to each user’s hot water demand. p To predict the power generated by PVT, W pc The electrical energy converted from the hot water produced by the PVT module, W n Electric energy converted to meet users' hot water demand.

[0037] b. If W p +W pc <W n , that is, when the electricity and hot water produced by PVT cannot meet the needs of all users, the power distribution strategy is as follows:

[0038] Each secondary heat storage tank supplies hot water to downstream users first.

[0039] When there is insufficient hot water in the secondary thermal storage tank, the PVT generates electricity and the hot water in the primary thermal storage tank is distributed according to the user's general water usage ratio, outputs hot water to the secondary thermal storage tank, and combines it with cold water for electrical heating.

[0040] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0041] 1. The present invention converts solar energy into electrical energy and thermal energy by setting up a PVT module, and then delivers hot water to the main thermal storage tank and the secondary thermal storage tank respectively, to provide users with hot water for daily use. By delivering hot water to the electric boiler to heat the radiator, the user's indoor temperature is kept within a preset temperature range, thereby improving the user's water convenience and indoor comfort.

[0042] 2. The present invention recycles the hot wastewater generated in the user's life by setting up a heat recovery control module, preheats the cold water by heat exchange, and then reduces the electric energy consumed by water heating, so that domestic water mainly depends on the PVT module, reduces water energy consumption, and further reduces the cost of domestic water. In the recovery of hot wastewater, by analyzing the user's domestic water use habits and combining the user's residence record, the user's daily hot water consumption is predicted, and then the hot wastewater generated by the user every day is predicted in combination with the environmental conditions, thereby optimizing the distribution method of the hot wastewater recovery cycle and further reducing the overall user's hot water consumption.

[0043] 3. The present invention reasonably distributes hot water and electricity to users based on the daily electricity and hot water output of the PVT module, more accurately evaluates the user's additional power consumption, and through comprehensive electricity distribution to all users, while protecting the interests of each user, achieves an electricity distribution method with the lowest energy consumption, effectively improves the utilization rate of the PVT module, and reduces the overall hot water use cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A framework diagram of a domestic wastewater recycling system capable of recovering heat energy according to the present invention;

[0045] Figure 2 For the present invention Figure 1 Framework diagram of the heat recovery control module;

[0046] Figure 3 For the present invention Figure 1 The framework diagram of the power distribution module;

[0047] Figure 4 It is a schematic diagram of the structure of the PVT heat storage heating and domestic hot water circulation system after the application of the present invention. DETAILED DESCRIPTION

[0048] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work all belong to the protection scope of the present invention. The experimental methods in the following embodiments, unless otherwise specified, are conventional methods, and the materials, reagents, etc. used in the following embodiments, unless otherwise specified, can all be obtained from commercial channels.

[0049] Example: Figure 1-Figure 4As shown, a domestic wastewater recycling system capable of recovering heat energy includes a PVT module, a primary heat storage tank, a secondary heat storage tank, an indoor heating module, a hot water circulation module, an electric power distribution module and a heat recovery control module.

[0050] The PVT module is used to absorb solar energy and convert it into electrical energy and thermal energy, wherein the electrical energy is used to power various electrical components in the domestic wastewater recycling system, and the thermal energy is used to heat tap water. In this embodiment, the PVT module, as the main source of domestic water for users, includes a solar photovoltaic unit and a photothermal unit, wherein the photovoltaic unit can convert solar energy into electrical energy, and then power household appliances. The photothermal unit can heat domestic water and work with the tap water system to meet the user's water needs.

[0051] The main thermal storage tank is connected to the PVT module. When the hot water in the PVT module reaches the preset temperature, it is transported to the main thermal storage tank. In addition, a heating wire is installed in the main thermal storage tank, which can be powered by the PVT module or the mains to heat the water in the main thermal storage tank. Generally speaking, when the water temperature inside the main thermal storage tank is lower than the preset minimum temperature, the internal water is heated to the preset maximum temperature through the heating wire. The hot water stored in the main thermal storage tank can be transported to the secondary thermal storage tank and the user's domestic water module.

[0052] The secondary thermal storage tank is connected to the main thermal storage tank. When the amount of hot water in the secondary thermal storage tank is lower than the user's demand, the hot water in the main thermal storage tank reaches the preset maximum temperature and is then transported to the secondary thermal storage tank. A heating wire is also installed in the secondary thermal storage tank to heat the water in the secondary thermal storage tank. If the amount of hot water or the temperature of the hot water in the main thermal storage tank is insufficient, the electric energy produced by the PVT module will be used to heat the water in the secondary thermal storage tank first.

[0053] In this embodiment, the capacity of the main heat storage tank is set to 1T, that is, 1m 3 The capacity of the secondary heat storage tank is set to 0.2T. The heating wires installed inside the primary and secondary heat storage tanks are both 2kw DC heating rods. The heating wires can be powered directly by the power output of the PVT module or by the mains. The preset maximum temperature of the primary heat storage tank is set to 80℃, and the preset minimum temperature is 30℃.

[0054] The indoor heating module includes an electric boiler and a radiator. The electric boiler is installed in the user's room and is connected to the primary heat storage tank and the secondary heat storage tank respectively. The water in the electric boiler is mainly used to heat the radiator to keep the indoor temperature within a preset temperature range. In this embodiment, the working voltage of the electric boiler is 220V, the power is 5W, and the capacity is 15L. The preset temperature range is set to 18~22℃.

[0055] The hot water circulation module includes multiple pipes, solenoid valves, filters, pressure switches, etc. Among them, the pipes are used to connect the PVT module, the main heat storage tank, the secondary heat storage tank, the indoor heating module, the user's domestic water module and the tap water system, and to form a circulation connection between the modules. The solenoid valves are installed on the pipes respectively to control the connection status of each pipe. Filters are installed between the main heat storage tank, the secondary heat storage tank and the indoor heating module to filter impurities in the domestic water. The pressure switch is installed on the pipe to control the water flow rate in the pipe. Specifically, in this embodiment, cold water is first transported to the PVT module through the tap water system. When the cold water in the PVT module is heated to a preset temperature, the water in the PVT module is transported to the main heat storage tank.

[0056] The heat recovery control module is used to perform heat exchange between the domestic hot wastewater discharged by the user and tap water. The domestic hot wastewater of the user generally includes the wastewater generated by the user's bathing, the wastewater discharged from the kitchen, etc. Generally speaking, the temperature of the wastewater generated after the user takes a bath is generally still above 35°C, and even in summer, the outdoor water temperature generally does not exceed 23°C, and the outdoor water temperature in winter is generally below 8°C. Therefore, heat exchange of tap water with domestic hot wastewater can effectively improve the utilization rate of wastewater and reduce the energy consumption in life. After the wastewater after heat exchange is further filtered, it can also be used for watering flowers, flushing toilets, etc. In this embodiment, the heat exchange process is realized by a heat exchanger.

[0057] The heat recovery control module includes a hot wastewater monitoring unit, a hot wastewater prediction unit and a heat exchange distribution unit. The hot wastewater monitoring unit is used to monitor the temperature and flow of the hot wastewater discharged by the user in real time, and separate the hot wastewater discharged by the user from the cold wastewater. In this embodiment, the minimum hot wastewater temperature is set according to the outdoor temperature. If the temperature of the domestic wastewater is higher than the minimum hot wastewater temperature, it is regarded as hot wastewater and heat exchanged with tap water. Otherwise, it is regarded as cold wastewater and directly discharged outdoors or used for other purposes, such as watering, flushing toilets, etc.

[0058] The hot wastewater prediction unit is used to predict the hot wastewater discharge and average temperature in the next period of time according to the hot water status used by the user and the current hot water temperature. Specifically, the hot wastewater discharged by the user is divided into bathing hot wastewater and kitchen waste hot wastewater. Among them, kitchen waste hot wastewater can be directly obtained through short-term measurement, and bathing hot wastewater is predicted based on user habits, outdoor temperature and the number of users in the family. Since kitchen waste hot wastewater is generally quickly introduced into the pool, there is no need for long-term monitoring, and the temperature of kitchen waste hot wastewater is difficult to predict, so real-time measurement is also required.

[0059] The method for predicting the discharge volume and average temperature of hot bathing wastewater is as follows:

[0060] First, the number of people bathing in each user's family on that day is obtained based on big data or travel records. Specifically, the number of people in each user's family is obtained through check-in registration, and the number of people at home on that day is obtained based on each person's travel record as the number of people bathing on that day.

[0061] Secondly, the bathing duration, water consumption, and bathing temperature of each person are analyzed based on the bathing water use history records of each user's family. The analysis process is as follows:

[0062] A bathing prediction model based on machine learning is established. User characteristics, environmental characteristics, and date characteristics are extracted from the historical data of bathing water use. These characteristics are used as input, and bathing duration, water consumption, and bathing temperature are used as output. The bathing prediction model is trained and the model parameters that meet the test accuracy are retained. Subsequently, the corresponding current user characteristics, current environmental characteristics, and current date characteristics are extracted based on the current user data, environmental data, and date data, and these characteristics are input into the trained bathing prediction model to obtain the corresponding predicted bathing duration t b , predicted water consumption V b , predict bath temperature T b .

[0063] Again, the heat loss rate η is measured according to the ambient temperature b and hot water evaporation rate η e , and then combined with the predicted bathing time, water consumption and bathing temperature, the total daily discharge volume and average temperature of bathing hot wastewater are calculated.

[0064] The total amount of hot wastewater discharged from bathing every day is V hp Expressed as:

[0065] V hp =V b (1-η e ).

[0066] Average temperature of hot wastewater T hp Expressed as:

[0067] T hp =T b -η b (t b -1) / 2.

[0068] The heat exchange distribution unit is used to calculate the heat exchange amount required for each user based on the hot water amount required by each user, the current hot water amount and the comprehensive hot wastewater amount, and then distribute it proportionally according to the hot wastewater discharged by each user to minimize the comprehensive hot water demand.

[0069] In this embodiment, considering that the hot water required by the user includes bathing hot water and room heating hot water, the amount of hot water required by the user V nIt can be expressed as:

[0070] V n =V b +V c

[0071] Where V c The demand for hot water for room heating is expressed as:

[0072] V c =v n t n

[0073] v n =K(T3-T4) / (T i -T0)

[0074] In the formula, v n Hot water demand rate for room heating, t n is the daily heating duration, K is the heat transfer coefficient, T0 is the current room temperature, T i is the heating hot water temperature, T3 is the room heating target temperature, and T4 is the outdoor temperature.

[0075] Proportional distribution at the nearest location means that the hot wastewater discharged by each user is first heat exchanged with the cold water used by itself. If the amount of stored hot water meets the water demand or there is still surplus hot wastewater for heat exchange, the remaining hot wastewater of all users will be counted and distributed to other users in proportion, and the hot wastewater of each user will be provided to other users at the nearest location. For example, when the secondary heat storage tank corresponding to each user needs to add hot water, and the amount of hot water in the main heat storage tank is insufficient or the hot water temperature is lower than the preset temperature, the corresponding secondary heat storage tank needs to add cold water and perform electric heating. At this time, this part of cold water can be heat exchanged with hot wastewater to reduce power consumption. If the amount of hot water in the secondary heat storage tank corresponding to the user is sufficient, the hot wastewater discharged will be counted and distributed in proportion according to the amount of hot water lacking by other users. In actual distribution, in order to reduce the heat loss of hot wastewater, hot wastewater will be provided to other users at the nearest location.

[0076] The power distribution module is used to distribute power to each user according to the daily power demand and the power produced by the PVT module, so as to minimize the total city power consumption. Specifically, the power distribution module includes a user hot water demand prediction unit, a PVT output prediction unit, a power distribution unit and a power real-time correction unit.

[0077] The user hot water demand prediction unit is used to calculate the user's hot water demand according to the user's current hot water inventory and the predicted user's required hot water quantity.

[0078] The current hot water storage includes the water storage volume V1 and temperature T1 of the main heat storage tank, the water storage volume V2 and temperature T2 of the secondary heat storage tank, and the hot water storage volume Veb , Temperature T eb The current hot water storage V s and average temperature T s They are:

[0079] V s =V1+V2+V eb

[0080] T s =(V1T1+V2T2+V eb T eb ) / (V1+V2+V eb )

[0081] In this embodiment, the number of primary heat storage tanks is 1, the number of secondary heat storage tanks is m, that is, the number of users is m, and the number of electric boilers is n. For each user, the current water storage capacity is:

[0082] V si =V ebi + (V1 + V2) / m

[0083] The corresponding average temperature is:

[0084] T si =(V1T1+V2T2+mV eb T eb ) / (V1+V2+mV eb ).

[0085] When the average water supply temperature is T i When the user's hot water demand V L Expressed as:

[0086] V L =V n -V si -V hc

[0087] Where V hc The equivalent amount of hot water for heat exchange is expressed as:

[0088] V hc =η c V hp (T hp -T5) / T i

[0089] Where η c is the heat exchange efficiency, and T5 is the cold water temperature.

[0090] The PVT output prediction unit is used to predict the amount of electricity and hot water produced by the PVT module on the day based on environmental parameters. Assuming that the efficiency of the PVT module in converting solar energy remains unchanged, the amount of electricity and hot water produced by the PVT module can be predicted by environmental changes. The specific steps are as follows:

[0091] First, a light prediction model based on deep learning is constructed, and the light prediction model is trained according to historical environmental data, and the model parameters that meet the test accuracy are retained. Specifically, the collected historical environmental data are preprocessed, including data cleaning, format conversion, etc., and the historical environmental data are normalized. Feature extraction is performed on the preprocessed historical environmental data to obtain basic meteorological features and date features. The historical environmental data is divided into a training set and a test set according to a preset ratio. The light prediction model is trained with the training set and verified with the test set until the test accuracy meets the preset accuracy, and the corresponding model parameters are retained. Subsequently, the recent environmental data is input into the light prediction model to obtain the predicted light data. The predicted output electrical energy W is calculated based on the light data and the conversion efficiency of the PVT module. p And hot water volume Q p .

[0092] The power distribution unit is used to distribute the power produced by the PVT module to the main heat storage tank and each secondary heat storage tank according to the predicted power output of the PVT module, the amount of hot water produced and the user's hot water demand, and calculate the additional power required by each user.

[0093] First, the hot water produced by the PVT module is converted into electrical energy as follows:

[0094] W pc =Q p W0 / V0

[0095] In the formula, W0 is the volume of cold water with a temperature of T4 heated to T i The electrical energy required.

[0096] The user's hot water demand is converted into electrical energy as:

[0097] W n =V n W0 / V0

[0098] Where V n The amount of hot water required by all users.

[0099] Then the allocation strategy of the power distribution unit is:

[0100] a. If W p +W pc ≥W n , the electricity produced by PVT is distributed in proportion to each user's hot water demand.

[0101] When there is sufficient sunlight, the electricity and hot water produced by the PVT module are sufficient to support the hot water demand of all users. At this time, the power distribution unit can distribute it in proportion to the demand of each user. For example, when there is sufficient sunlight, the PVT module fills the main heat storage tank, the secondary heat storage tank and the electric boiler with hot water, and stores the produced electricity. Since the amount of hot water used by users at night is generally higher than that used during the day, most of the electricity produced by the PVT module is distributed at night.

[0102] b. If W p +W pc <W n , that is, when the electricity and hot water produced by PVT cannot meet the needs of all users, the power distribution strategy is as follows:

[0103] Each secondary heat storage tank gives priority to supplying hot water to downstream users;

[0104] When there is insufficient hot water in the secondary thermal storage tank, the PVT generates electricity and the hot water in the primary thermal storage tank is distributed according to the user's general water usage ratio, outputs hot water to the secondary thermal storage tank, and combines it with cold water for electrical heating.

[0105] The additional power required by the user is W nei Expressed as:

[0106] W nei =W ni -W pi -W pci -W hci

[0107] Where W ni is the equivalent electricity of the current user’s hot water demand, W pi PVT power allocated to the current user, W pci PVT hot water equivalent electric energy allocated to current users, W hci It is the heat exchange equivalent electric energy of the current user.

[0108] The real-time power correction unit is used to make real-time corrections to the power distribution module according to the actual amount of hot water used by the user. There will be a deviation between the hot water used by each user in actual life and the predicted amount, and the hot wastewater generated by the user's life will be heat exchanged with the cold water used by itself first. If the user's actual water consumption is much higher than the predicted amount, all the hot wastewater generated by it will be heat exchanged with the cold water used by itself. If the user's actual water consumption is much lower than the predicted amount, the hot wastewater generated by it can be heat exchanged with other users with higher water consumption to reduce overall energy consumption. Among them, the equivalent electric energy of the excess hot wastewater discharged by the user's life can be counted in the PVT output electric energy for overall distribution.

[0109] The domestic wastewater recycling system of this embodiment converts solar energy into electrical energy and thermal energy by setting up a PVT module, and then delivers hot water to the main heat storage tank and the secondary heat storage tank respectively, to provide users with domestic hot water. By delivering hot water to the electric boiler and then heating the radiator, the user's indoor temperature is kept within a preset temperature range, thereby improving the user's water convenience and indoor comfort. In addition, this embodiment recycles the hot wastewater generated in the user's life by setting up a heat recovery control module, preheats the cold water by heat exchange, and then reduces the electric energy consumed by water heating, so that domestic water mainly depends on the PVT module, reduces water consumption, and further reduces the cost of domestic water. In the recovery of hot wastewater, by analyzing the user's domestic water use habits and combining the user's residence record, the user's daily hot water consumption is predicted, and then the user's daily hot wastewater generated by the environmental conditions is predicted, thereby optimizing the distribution method of the hot wastewater recovery cycle and further reducing the overall user's hot water consumption. Therefore, based on the daily electricity and hot water output of the PVT module, hot water and electricity can be reasonably allocated to users, and the user's additional electricity consumption can be more accurately evaluated. Through comprehensive electricity distribution to all users, while protecting the interests of each user, the electricity distribution method with the lowest energy consumption is achieved, which effectively improves the utilization rate of the PVT module and reduces the overall hot water usage cost.

[0110] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto, and various changes can be made within the knowledge scope of technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A domestic wastewater recycling system capable of recovering heat energy, characterized in that: include: PVT module, used to absorb solar energy and convert it into electrical energy and thermal energy; A main heat storage tank, connected to the PVT module; A secondary heat storage tank, connected to the primary heat storage tank and the PVT module respectively; The indoor heating module comprises an electric boiler and a radiator. The electric boiler is installed in the user's room and is connected to the main heat storage tank and the secondary heat storage tank respectively. The radiator is installed in the user's room and is used to absorb the heat of the hot water in the electric boiler and convert it into air heat. Heat recovery control module, used to exchange heat between domestic hot wastewater discharged by users and tap water; Hot water circulation module, used to control the water delivery status and delivery direction between modules; A power distribution module, used to distribute power to each user according to the user's daily power demand and the power produced by the PVT module, so as to minimize the total city power consumption; The power distribution module includes a user hot water demand prediction unit, a PVT output prediction unit, a power distribution unit and a power real-time correction unit; the user hot water demand prediction unit is used to calculate the user's hot water demand according to the user's current hot water inventory and the predicted user's required hot water; the PVT output prediction unit is used to predict the electric energy and hot water output of the PVT module on the day according to environmental parameters; the power distribution unit is used to distribute the electric energy produced by the PVT module to the main heat storage tank and each secondary heat storage tank according to the predicted PVT module output electric energy, output hot water and user hot water demand, and calculate the additional electric energy required for each user; The power real-time correction unit is used to correct the power distribution module in real time according to the amount of hot water actually used by the user; In the user hot water demand prediction unit, the user hot water demand V L Expressed as: V L =V n -V si -V hc Where V n is the amount of hot water required by the user, V si is the current water storage capacity, V hc The equivalent amount of hot water for heat exchange is expressed as: V hc =η c V hp (T hp -T5) / T i Where η c is the heat exchange efficiency, V hp is the total daily discharge of hot wastewater from bathing, T hp is the average temperature of hot wastewater, T5 is the cold water temperature, T i The temperature of hot water for heating.

2. A domestic wastewater recycling system capable of recovering heat energy according to claim 1, characterized in that: The PVT module includes a solar photovoltaic unit and a photothermal unit. The photovoltaic unit is used to convert solar energy into electrical energy; the photothermal unit is used to heat tap water.

3. A domestic wastewater recycling system capable of recovering heat energy according to claim 2, characterized in that: Heating wires are installed in both the main heat storage tank and the secondary heat storage tank; the heating wires are electrically connected to the photovoltaic unit.

4. A domestic wastewater recycling system capable of recovering heat energy according to claim 1, characterized in that: The hot water circulation module includes multiple pipes, solenoid valves, filters and pressure switches; the multiple pipes are used to connect the PVT module, the main heat storage tank, the secondary heat storage tank, the indoor heating module, the user's domestic water module and the tap water system, and form a circulation connection between the modules; the solenoid valves are respectively installed on the pipes to control the connection state of the pipes; the filters are installed on the pipes to filter impurities in the pipe water; the pressure switches are installed on the pipes to control the water flow rate in the pipe.

5. The domestic wastewater recycling system capable of recovering heat energy according to claim 1, characterized in that: The heat energy recovery control module includes a hot wastewater monitoring unit, a hot wastewater prediction unit and a heat exchange distribution unit; the hot wastewater monitoring unit is used to monitor the temperature and flow of hot wastewater discharged by users in real time, and separate the hot wastewater discharged by users from cold wastewater; the hot wastewater prediction unit is used to predict the hot wastewater discharge volume and average temperature of the next period of time according to the hot water status used by users and the current hot water temperature; the heat exchange distribution unit is used to calculate the heat exchange amount required by each user according to the hot water amount required by each user, the current hot water amount and the comprehensive waste water amount, and then distribute it in proportion to the hot wastewater discharged by each user to minimize the comprehensive hot water demand.

6. A domestic wastewater recycling system capable of recovering heat energy according to claim 5, characterized in that: The method for predicting the discharge volume and average temperature of the hot wastewater from bathing by the hot wastewater monitoring unit is as follows: Get the number of people bathing in each user's family on that day; According to the bathing water history records of each user's family, each person's bathing time, water consumption, and bathing temperature are analyzed: a bathing prediction model based on machine learning is established, user characteristics, environmental characteristics, and date characteristics are extracted from the bathing water history data, and these characteristics are used as input, and bathing time, water consumption, and bathing temperature are used as output. The bathing prediction model is trained and the model parameters that meet the test accuracy are retained; according to the current user data, environmental data, and date data, the corresponding current user characteristics, current environmental characteristics, and current date characteristics are extracted, and input into the trained bathing prediction model to obtain the corresponding predicted bathing time t b , predicted water consumption V b , predict bath temperature T b ; Query the heat loss rate η according to the ambient temperature b and hot water evaporation rate η e , and then the total discharge volume and average temperature of daily hot bathing wastewater are calculated based on the predicted bathing time, water consumption and bathing temperature; The total amount of hot wastewater discharged from bathing every day is V hp Expressed as: V hp =V b (1-η e ) Where V b To predict water consumption, η e is the hot water evaporation rate; Average temperature of hot wastewater T hp Expressed as: T hp =T b -η b (t b -1) / 2 Where, T b To predict the bath temperature, t b To predict the bathing time, η b is the heat loss rate.

7. A domestic wastewater recycling system capable of recovering heat energy according to claim 1, characterized in that: The specific prediction steps of the PVT output prediction unit are as follows: Build a lighting prediction model based on deep learning; Collect historical environmental data and pre-process them; Extract features from the preprocessed historical environmental data to obtain basic meteorological features and date features; Divide the historical environmental data into a training set and a test set according to a preset ratio, use the training set to train the illumination prediction model, and use the test set to verify it until the test accuracy meets the preset accuracy, and retain the corresponding model parameters; Input recent environmental data into the light prediction model to obtain predicted light data; The predicted output power W is calculated based on the light data and the conversion efficiency of the PVT module. p And hot water volume Q p .

8. The domestic wastewater recycling system capable of recovering heat energy according to claim 1, characterized in that: The distribution strategy of the power distribution unit is: a. If W p +W pc ≥W n , then the electricity produced by PVT is distributed in proportion to the hot water demand of each user; where W p is the predicted output power, W pc The equivalent electrical energy converted from the hot water produced by the PVT module, W n Equivalent electrical energy converted to the user's hot water demand; b. If W p +W pc <W n , that is, when the electricity and hot water produced by PVT cannot meet the needs of all users, the power distribution strategy is as follows: Each secondary heat storage tank gives priority to supplying hot water to downstream users; When the hot water in the secondary thermal storage tank is insufficient, the PVT generates electric energy and the hot water in the primary thermal storage tank is distributed according to the user's general water usage ratio, outputs hot water to the secondary thermal storage tank, and combines it with cold water for electrical heating.

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