Control method and device for sustainable renewable energy heat supply system

Abstract

The invention relates to the technical field of heat supply systems, in particular to a control method and device for a sustainable renewable energy source heat supply system. The control method is executed by a PLC and comprises a heat charging control process and a heat releasing control process, and the heat charging control process comprises the steps that the total return water temperature T is obtained in real time, when T is larger than T0, a heat charging mode is activated, a heat charging valve is opened, a heat releasing valve is closed, the opening K1 of an adjusting valve is dynamically adjusted, a water body flows along a heat charging path, and the two-way heat charging and releasing module stores heat; according to the heat release control process, the real-time direct heat supply efficiency eta is achieved, when eta is smaller than eta 0, the heat release activation mode is executed, the heat release valve is opened, the heat charging valve is closed, the opening K2 of the adjusting valve is dynamically adjusted, and the stored heat is released by the two-way heat charging and discharging module. The invention further discloses a control device for implementing the control method. On the basis of real-time T and eta dynamic closed-loop control, heat storage and release actions of the heat supply system are synchronized with user demand changes, and the problem that supply-demand balance of the heat supply system is broken due to delay is fundamentally solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat supply systems, in particular to a control method and device for a sustainable renewable energy heat supply system. BACKGROUND

[0002] The trend of replacing traditional energy with renewable energy is gradually emerging. Renewable energy refers to energy that is continuously replenished and regenerated through natural processes within a short period of time, including water energy, wind energy, solar energy, biomass energy, geothermal energy, and ocean energy.

[0003] However, the above-mentioned renewable energy inevitably has the defect of being unsustainable, resulting in low utilization rate and a large amount of energy waste.

[0004] At the same time, such renewable energy and its heat supply technology generally have inherent intermittency and volatility defects, mainly manifested as "day / night and seasonal supply and demand imbalance". For example, air energy: the ambient air temperature fluctuates greatly with day and night and seasons, directly affecting the efficiency of air source heat pumps; solar energy: directly dependent on light intensity and duration, with day and night alternation, sunny and cloudy changes, and seasonal differences; wind energy / water energy: although not the main force for direct heating, if used to drive heat pumps or heating, its output is also limited by natural conditions.

[0005] Therefore, the instability of renewable energy leads to a mismatch between energy supply and heat load demand in time; in order to overcome this core challenge, not only is it necessary to release the converted and stored energy according to the demand in different time periods or continuously, but also it is necessary to have a high-efficiency, large-capacity heat storage type heat supply system.

[0006] Subsequently, various technical solutions for energy storage have emerged, but these existing technical solutions all have the following defects:

[0007] 1. Energy storage is not timely;

[0008] 2. Energy loss is large during energy storage;

[0009] 3. The stored energy cannot be provided to the next stage in time or continuously;

[0010] For example, in the patent technical solutions with publication numbers CN108917229A, CN114593477A, CN117273329A, etc., attention is paid to controlling the heat storage and release of the heat supply system using electricity prices, water level thresholds, environmental temperatures, or predicted weather changes. There is always a "time difference" between the heat storage and release action and the change in user demand, and the defect of continuous energy release has not been solved.

[0011] The patent technical solution with the publication number CN109084359A focuses on using solar heat or using solar heat combined with conventional energy to supply heat, which maximizes the use of solar energy, but still cannot solve the problem of spatial separation between solar heat supply and user demand changes, and still has the above defects.

[0012] The core contradiction of the heat supply system as a high-inertia thermodynamic system is that the user demand change rate (minute level) >> system heat storage and release response rate (30 minute level); and the existing control method lacks real-time dynamic closed-loop feedback, and is always "chasing demand", which leads to user immediate heat shortage due to heat storage of the heat supply system invading direct heat supply, and continuous user heat shortage due to demand peak after heat release of the heat supply system. SUMMARY

[0013] The application provides a sustainable renewable energy heat supply system control method and device, which synchronizes the heat storage and release action of the heat supply system with the user demand change based on real-time T and η, and fundamentally solves the problem of breaking the heat supply-demand balance due to time delay.

[0014] An object of the application is to provide a sustainable renewable energy heat supply system control method applied to a sustainable heat supply system comprising a direct heat supply circulating main loop and a bidirectional heat charging and releasing module.

[0015] The direct heat supply circulating main loop is formed by sequentially unidirectionally connecting a heater, a heat supply pipe network, a return water pipe network, and a heat pump to form a closed loop.

[0016] The bidirectional heat charging and releasing module is connected to the direct heat supply circulating main loop through a heat charging path and a heat releasing path, wherein the heat charging path is connected to the suction end of the heat pump through the heat supply pipe network, a heat charging valve, the bidirectional heat charging and releasing module, and a regulating valve, the heat releasing path is connected to the heat supply pipe network through the discharge end of the heat pump, a heat releasing valve, the bidirectional heat charging and releasing module, and the regulating valve, and satisfies:

[0017] a. The heat charging path and the heat releasing path share the same bidirectional heat charging and releasing module and the same regulating valve;

[0018] b. The water flow direction of the heat charging path is opposite to that of the heat releasing path;

[0019] c. The heat charging valve and the heat releasing valve are independently arranged in different pipelines.

[0020] The control method is executed by a PLC and includes the following steps:

[0021] 1) Heat charging control process:

[0022] A total return water temperature threshold T0 is preset.

[0023] Real-time acquisition of total return water temperature T of direct supply heat cycle main loop and current power period state;

[0024] When the heater is in non-power peak period and the total return water temperature T is greater than the preset threshold T0, execute:

[0025] 1.1, activate the bidirectional heat charging and discharging module to the heat charging mode;

[0026] 1.2, open the heat charging valve and close the heat discharging valve;

[0027] 1.3, dynamically adjust the opening degree K1 of the regulating valve, so that the water flows along the heat charging path and the bidirectional heat charging and discharging module stores heat;

[0028] 1.4, continuously monitor the heat charging end condition, and execute when any of the following 1.4.1-1.4.3 conditions is met:

[0029] 1.4.1, when the heat charging amount of the bidirectional heat charging and discharging module reaches 100%, close the heat charging valve and the regulating valve, and keep the bidirectional heat charging and discharging module standby;

[0030] 1.4.2, when the heater enters the power peak period, close the heat charging valve, adjust the regulating valve to a safe opening degree, and make the bidirectional heat charging and discharging module enter the heat discharging control process in step 2) and standby for heat discharging;

[0031] 1.4.3, when T≤T0, the bidirectional heat charging and discharging module enters the heat charging mode standby state;

[0032] 2) Heat discharging control process:

[0033] Preset direct supply heat efficiency threshold η0 of direct supply heat cycle main loop;

[0034] Real-time calculation of direct supply heat efficiency η of direct supply heat cycle main loop, and acquisition of current power period state;

[0035] When the heater is in power peak period and the direct supply heat efficiency η is less than the direct supply heat efficiency threshold η0, execute:

[0036] 2.1, activate the bidirectional heat charging and discharging module to the heat discharging mode;

[0037] 2.2, open the heat discharging valve and close the heat charging valve, so that the water flows along the heat discharging path;

[0038] 2.3, dynamically adjust the opening degree K2 of the regulating valve, so that the bidirectional heat charging and discharging module releases the stored heat;

[0039] 2.4, continuously monitor the heat discharging end condition, and execute when any of the following 2.4.1-2.4.3 conditions is met:

[0040] 2.4.1, when the heat charging amount of the bidirectional heat charging and discharging module is reduced to 0%, the heat discharging valve and the adjusting valve are closed, and the bidirectional heat charging and discharging module is kept standby;

[0041] 2.4.2, when the heater enters a non-power peak period, the heat discharging valve is closed, the adjusting valve is adjusted to a safe opening degree, the bidirectional heat charging and discharging module is switched to step 1) heat discharging control process and heat charging standby;

[0042] 2.4.3, when η≥η0, the bidirectional heat charging and discharging module is in standby state in heat discharging mode.

[0043] In one specific embodiment of the present application, the total return water temperature threshold T0 is in the range of 41-45℃.

[0044] In one specific embodiment of the present application, the direct heating efficiency threshold η0 is the direct heating efficiency value determined according to the performance coefficient COP and the comprehensive part load performance coefficient IPLV specified in GB 19577-2024 “Energy Efficiency Limiting Value and Energy Efficiency Grade of Heat Pump and Water Chiller”.

[0045] In one specific embodiment of the present application, the bidirectional heat charging and discharging module is composed of a heat storage tank, a heat exchanger, a heat storage pump, valves V1, V2, V3, V4, V5 and V5; wherein the high-temperature fluid port of the heat storage tank is in fluid communication with the high-temperature port of the secondary side of the heat exchanger through valve V5, the low-temperature port of the secondary side of the heat exchanger is in fluid communication with the low-temperature fluid port of the heat storage tank through valve V6, the suction end of the heat storage pump is in fluid communication with the high-temperature fluid port through valve V1, the suction end of the heat storage pump is also in fluid communication with the low-temperature fluid port through valve V2, the discharge end of the heat storage pump is in fluid communication with the high-temperature port of the secondary side through valve V3, and the discharge end of the heat storage pump is in fluid communication with the low-temperature port of the secondary side through valve V4; when the heat storage pump is running, valves V1, V3 and V6 are opened, and valves V2, V4 and V5 are closed, the heat discharging mode of the bidirectional heat charging and discharging module is activated; when the heat storage pump is running, valves V1, V3 and V6 are closed, and valves V2, V4 and V5 are opened, the heat charging mode of the bidirectional heat charging and discharging module is activated.

[0046] In one specific embodiment of the present application, the heat exchanger comprises at least one plate heat exchanger.

[0047] In one specific embodiment of the present application, the heat discharging valve and the heat charging valve are interlocked by PLC.

[0048] In one specific embodiment of the present application, the adjustment of opening degree K1 and opening degree K2 both adopts PID control algorithm.

[0049] In one specific embodiment of the present application, the adjusting valve is any one of electric adjusting valve, pneumatic adjusting valve and hydraulic adjusting valve.

[0050] The second object of the present application is to provide a control device for a sustainable renewable energy heating system, comprising:

[0051] A direct heating cycle main loop formed by a closed loop of a heater, a heating pipe network, a return pipe network and a heating pump connected in sequence in one direction;

[0052] A bidirectional heat charging and discharging module connected to the direct heating cycle main loop through a heat charging path and a heat discharging path; wherein the heat charging path is connected from the heating pipe network to the suction end of the heating pump through a heat charging valve, the bidirectional heat charging and discharging module and a regulating valve, and the heat discharging path is connected from the discharge end of the heating pump to the heating pipe network through a heat discharging valve, the bidirectional heat charging and discharging module and the regulating valve;

[0053] A total return water temperature sensor for real-time collection of the total return water temperature T of the direct heating cycle main loop;

[0054] A heating efficiency calculator for real-time calculation of the direct heating efficiency η of the direct heating cycle main loop;

[0055] A power period identification module for obtaining the peak and valley state of the power grid;

[0056] A PLC connected to the total return water temperature sensor, the heating efficiency calculator and the power period identification module;

[0057] The PLC is programmed to perform the above-mentioned control method.

[0058] The beneficial effects of the present application are:

[0059] 1. The present application sets a total return water temperature threshold and monitors the return water temperature in real time, and the system activates the heat charging mode of the bidirectional heat charging and discharging module according to the monitoring sample value, determines whether to open or close the regulating valve 3 and the heat charging valve 4, thereby solving the defect of untimely energy storage in the prior art;

[0060] 2. The present application optimizes the bidirectional heat charging and discharging module of the heating system and combines the heat charging path into a single pump delivery, and through valve switching, the heat charging and discharging process of reverse convection heat exchange is constructed by using the heat exchanger, thereby solving the technical defect of excessive energy loss during energy storage in the prior art;

[0061] 3. The present application sets a direct heating efficiency and calculates the real-time direct heating efficiency of the main loop, activates the heat discharging mode of the bidirectional heat charging and discharging module according to the calculation result value, determines whether to open or close the regulating valve 3 and the heat discharging valve, and heats the low-temperature return water to high-temperature water for heating, thereby solving the defect that the stored energy cannot be timely or continuously provided to the next stage;

[0062] 4、The application synchronizes the heat storage and release action of the heating system with the change of user demand for the first time through dynamic closed-loop control based on total return water temperature, fundamentally solving the problem of supply-demand balance breaking due to time delay in the heating system;

[0063] 5、The control method of the application can eliminate the energy supply invasion of the sustainable heating system during the heat charging phase, and strictly limit the heat charging action to the "user demand valley period";

[0064] 6、The η is an early signal of network performance degradation, which can respond and perform heat release action ≥15min in advance, so that the heat charging in the bidirectional heat charging and releasing module can be fully used for heating energy efficiency degradation compensation, and the heat charging heat energy utilization efficiency is improved;

[0065] 7、The control method of the application can overcome the influence of unstable renewable energy on heating in the renewable energy heating system, and improve the efficiency of the heating system. BRIEF DESCRIPTION OF DRAWINGS

[0066] Figure 1 The logical block diagram of the control method of the sustainable heating system of the application;

[0067] Figure 2 The structural schematic diagram of the control device of the sustainable heating system of the application;

[0068] Figure 3 The structural schematic diagram of the sustainable heating system of the application;

[0069] Figure 4 The structural schematic diagram of the heat exchanger of the application.

[0070] In the drawings, the components represented by each reference numeral are listed as follows:

[0071] 1, direct heating circulation main loop; 11, heater; 12, heating pipe network; 13, return water pipe network; 14, heating pump; 2, bidirectional heat charging and releasing module; 21, heat storage tank; 22, heat exchanger; 221, primary side high temperature port; 222, primary side low temperature port; 223, secondary side high temperature port; 224, secondary side low temperature port; 23, heat storage pump; 3, regulating valve; 4, heat charging valve; 5, heat releasing valve; 6, PLC; 7, total return water temperature sensor; 8, heating efficiency calculator; 9, power period identification module. DETAILED DESCRIPTION

[0072] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0073] Embodiments

[0074] Based on the Figures 1-4 The present embodiment provides a control method of a sustainable renewable energy heating system, applied to a sustainable heating system comprising a direct heating circulation main loop 1 and a bidirectional heat charging and discharging module 2;

[0075] The direct heating circulation main loop 1 is formed into a closed loop by a heater 11, a heating pipe network 12, a return water pipe network 13 and a heat pump 14 in sequence in one-way communication;

[0076] The bidirectional heat charging and discharging module 2 connects the main loop through a heat charging path and a heat discharging path; wherein the heat charging path is connected to the suction end of the heat pump 14 through the heating pipe network 12, a heat charging valve 4, the bidirectional heat charging and discharging module 2 and a regulating valve 3, and the heat discharging path is connected to the heating pipe network 12 through the discharge end of the heat pump 14, a heat discharging valve 5, the bidirectional heat charging and discharging module 2 and the regulating valve 3, and satisfies:

[0077] a. The heat charging path and the heat discharging path share the same bidirectional heat charging and discharging module 2 and the same regulating valve 3;

[0078] b. The water flow direction of the heat charging path is opposite to that of the heat discharging path;

[0079] c. The heat charging valve 4 and the heat discharging valve 5 are independently arranged in different pipelines;

[0080] The control method is executed by a PLC 6, comprising the following steps:

[0081] 1) Heat charging control process:

[0082] A total return water temperature threshold T0 is preset;

[0083] The total return water temperature T of the direct heating circulation main loop 1 and the current power period state are obtained in real time;

[0084] When the heater 11 is in a non-peak power period and the total return water temperature T is greater than the preset threshold T0, the following is executed:

[0085] 1.1, activate the bidirectional heat charging and discharging module 2 to the heat charging mode;

[0086] 1.2, open the heat charging valve 4 and close the heat discharging valve 5, so that the water flows along the heat charging path;

[0087] 1.3, dynamically adjust the opening degree K1 of the regulating valve 3 to make the bidirectional charging and discharging heat module 2 store heat;

[0088] 1.4, continuously monitor the charging end condition, and execute when any of the following conditions 1.4.1-1.4.3 is met:

[0089] 1.4.1, when the charging amount of the bidirectional charging and discharging heat module 2 reaches 100%, close the charging valve 4 and the regulating valve 3, and keep the bidirectional charging and discharging heat module 2 standby;

[0090] 1.4.2, when the heater 11 enters the power peak period, close the charging valve 4, adjust the regulating valve 3 to a safe opening degree, and make the bidirectional charging and discharging heat module 2 enter the step 2) discharging control process and standby in discharging mode;

[0091] 1.4.3, when T≤T0, the bidirectional charging and discharging heat module 2 is in standby state in charging mode;

[0092] 2) Discharging control process:

[0093] preset a direct heating cycle main loop 1 direct heating efficiency threshold η0;

[0094] calculate the direct heating efficiency η of the direct heating cycle main loop 1 in real time, and obtain the current power period state;

[0095] when the heater 11 is in the power peak period and the direct heating efficiency η is less than the direct heating efficiency threshold η0, execute:

[0096] 2.1, activate the bidirectional charging and discharging heat module 2 to discharging mode;

[0097] 2.2, open the discharging valve 5 and close the charging valve 4 to make the water flow along the discharging path;

[0098] 2.3, dynamically adjust the opening degree K2 of the regulating valve 3 to make the bidirectional charging and discharging heat module 2 release the stored heat;

[0099] 2.4, continuously monitor the discharging end condition, and execute when any of the following conditions 2.4.1-2.4.3 is met:

[0100] 2.4.1, when the charging amount of the bidirectional charging and discharging heat module 2 decreases to 0%, close the discharging valve 5 and the regulating valve 3, and keep the bidirectional charging and discharging heat module standby;

[0101] 2.4.2, when the heater 11 enters the non-power peak period, close the discharging valve 5, adjust the regulating valve 3 to a safe opening degree, and make the bidirectional charging and discharging heat module 2 enter the step 1) discharging control process and standby in charging mode;

[0102] 2.4.3, when η≥η0, the bidirectional charging and discharging heat module 2 is in standby state in discharging mode.

[0103] In some examples, the total return water temperature threshold T0 is in the range of 41-45℃.

[0104] In some examples, the direct heating efficiency threshold η0 is a direct heating efficiency value determined according to the coefficient of performance COP and the integrated part load performance coefficient IPLV specified in GB 19577-2024 “Energy Efficiency Limits and Energy Efficiency Grades for Heat Pumps and Water Chillers”.

[0105] In some examples, the bidirectional heat charging and discharging module 2 is composed of a heat storage tank 21, a heat exchanger 22, a heat storage pump 23, a valve V1, a valve V2, a valve V3, a valve V4, a valve V5, and a valve V5; wherein the high-temperature fluid port of the heat storage tank 21 is in fluid communication with the secondary side high-temperature port 223 of the heat exchanger 22 through the valve V5, the low-temperature fluid port of the heat storage tank 21 is in fluid communication with the secondary side low-temperature port 224 of the heat exchanger 22 through the valve V6, the suction end of the heat storage pump 23 is in fluid communication with the high-temperature fluid port through the valve V1, the suction end of the heat storage pump 23 is also in fluid communication with the low-temperature fluid port through the valve V2, the discharge end of the heat storage pump 23 is in fluid communication with the secondary side high-temperature port 223 through the valve V3, and the discharge end of the heat storage pump 23 is in fluid communication with the secondary side low-temperature port 224 through the valve V4; when the heat storage pump 23 is running, the valves V1, V3, and V6 are open, and the valves V2, V4, and V5 are closed, the heat discharging mode of the bidirectional heat charging and discharging module 2 is activated; when the heat storage pump 23 is running, the valves V1, V3, and V6 are closed, and the valves V2, V4, and V5 are open, the heat charging mode of the bidirectional heat charging and discharging module 2 is activated.

[0106] In some examples, the heat exchanger 22 includes at least one plate heat exchanger; when there are multiple plate heat exchangers, each plate heat exchanger is provided with a primary side high-temperature port 221, a primary side low-temperature port 222, a secondary side high-temperature port 223, and a secondary side low-temperature port 224; wherein in the heat charging mode, the high-temperature water flowing into the primary side high-temperature port 221 is heat transferred to the secondary side and heats the low-temperature heat storage fluid flowing into the secondary side low-temperature port 224, which is discharged from the secondary side high-temperature port 223, and the low-temperature water after heat transfer is discharged from the primary side low-temperature port 222; in the heat discharging mode, the secondary side high-temperature port 223 delivers high-temperature heat storage fluid into the heat exchanger 22, which is heat transferred to the primary side and heats the low-temperature water flowing into the primary side low-temperature port 222, which is discharged from the primary side high-temperature port 221 into the heating pipe network 12, and the low-temperature heat storage fluid after heat exchange is discharged from the secondary side low-temperature port 224.

[0107] It should be noted that the naming of the four ports of the heat exchanger 22 is based on its fixed structural position in the heat exchanger 22, regardless of the direction of fluid flow; in the charging or discharging mode, the same port can be dynamically used as an inlet or outlet, without the need to redefine the name, and only needs to connect the corresponding high / low temperature fluid pipeline according to the current working condition.

[0108] It should also be noted that the charging or discharging mode is in the opposite direction of the water and the heat storage fluid in the plate heat exchanger 22 to ensure the heat exchange quality.

[0109] In some examples, the once side low temperature port 222 is connected with a three-way, which combines the charging path and the discharging path, the first end of the three-way is connected with the once side low temperature port 222, the second end is connected with the charging valve 4, and the third end is connected with the discharging valve 5.

[0110] In some examples, the discharging valve 5 and the charging valve 4 are interlocked by the PLC 6.

[0111] In some examples, the adjustment of the opening K1 and the opening K2 both adopts a PID control algorithm.

[0112] In some examples, in order to facilitate the adjustment of the fluid flow in the charging path and the discharging path, the regulating valve 3 is any one of an electric regulating valve 3, a pneumatic regulating valve 3 and a hydraulic regulating valve 3.

[0113] In some examples, in order to coordinate the low temperature water quantity in the return water pipe network 13 is always less than the high temperature water quantity of the heating pipe network 12, the sustainable renewable energy heating system further comprises a water supplement device; the water supplement device is composed of a heating water supplement pipe, a pressure tank, a constant pressure water supplement pump, a soft water tank and a full-automatic soft water tank, the pressure tank and the constant pressure water supplement pump are arranged on the heating water supplement pipe, one end of the heating water supplement pipe is connected with the suction end of the heating pump 14, the other end is connected with the outlet of the soft water tank, the outlet of the full-automatic soft water tank is connected with the inlet of the soft water tank, and the inlet of the soft water tank is provided with a float ball water supplement valve.

[0114] In some examples, when the heat storage fluid in the bidirectional charging and discharging module 2 is soft water, the outlet of the soft water tank is further connected with the heat storage tank 21 through a heat storage water supplement pipe, and a heat storage water supplement pump is arranged on the heat storage water supplement pipe.

[0115] In some examples, the suction end of the heating pump 14 is further provided with an electronic descaler to avoid the entry of hard water into the return water pipe and scaling under the action of heat.

[0116] In some examples, in order to more accurately collect the heating heat energy, i.e. the flow of the heating pipe network 12, a remote heat meter and a flow meter are arranged on the heating pipe network 12.

[0117] The embodiment also provides a control device of the sustainable renewable energy heating system, which comprises:

[0118] The direct heating cycle main loop 1 is formed by the heating device 11, the heating pipe network 12, the return water pipe network 13 and the heating pump 14 in sequence and unidirectionally connected to form a closed loop.

[0119] The bidirectional heat charging and discharging module 2 is connected to the direct heating cycle main loop 1 through a heat charging path and a heat discharging path; wherein the heat charging path is connected to the suction end of the heating pump 14 through the heating pipe network 12, the heat charging valve 4, the bidirectional heat charging and discharging module 2 and the regulating valve 3; the heat discharging path is connected to the heating pipe network 12 through the discharge end of the heating pump 14, the heat discharging valve 5, the bidirectional heat charging and discharging module 2 and the regulating valve 3.

[0120] The total return water temperature sensor 7 collects the total return water temperature T of the direct heating cycle main loop 1 in real time.

[0121] The heating efficiency calculator 8 calculates the direct heating efficiency η of the direct heating cycle main loop 1 in real time.

[0122] The power period identification module 9 obtains the peak and valley state of the power grid.

[0123] The PLC 6 is connected to the total return water temperature sensor 7, the heating efficiency calculator 8 and the power period identification module 9.

[0124] The PLC 6 is programmed to perform the above-mentioned control method.

[0125] It should be noted that in order to ensure that hot water and heat storage fluid can be normally transported and work, the heating pump and the heat storage pump are used alternately.

[0126] The air source heat pump direct heating process is as follows:

[0127] Air source heat pump direct heating: the air source heat pump prepares 55℃ hot water, which is transported to the user end through the heating pipe network 12 for use, and 45℃ cold water is recovered through the return water pipe network 13 and recycled to the heating device for reheating; the heating process uses the heat pump to provide transportation power.

[0128] Air source heat pump heat charging: the regulating valve 3 of the heat charging path has an opening degree K1, a part of 55℃ hot water in the heating main pipe enters the heat exchanger 22 from the primary high temperature port for heat charging, and 45℃ cold water is obtained after heat charging and transported to the air source heat pump by the heating pump 14 for reheating; the pump valve of the bidirectional heat charging and discharging module 2 is switched to the heat charging mode, 43℃ cold water in the bottom low temperature area of the heat storage tank 21 is input into the heat exchanger 22 from the heat storage pump 23 and the secondary cold water port for heat charging, 53℃ hot water is obtained from the secondary high temperature port 223 and stored in the top high temperature area of the heat storage tank 21; at this time, in the heat exchanger, 43℃ cold water enters the heat exchanger from the secondary cold water port and reversely flows and exchanges heat with 55℃ hot water entering the heat exchanger from the primary high temperature port, so as to realize heat charging.

[0129] Air source heat pump heat release: the opening degree K2 of the regulating valve 3 of the heat release path, the 41℃ cold water of the water pipe network 13 is transported by the heat release valve 5 and the primary side low temperature port 222 into the heat exchanger 22 to receive heat release, and 51℃ hot water is obtained, and the primary side high temperature port 221 and the regulating valve 3 enter the heat supply pipe network 12 to supply heat; the pump valve of the bidirectional heat charging and releasing module 2 is switched to the heat release mode, the 53℃ hot water in the top high temperature area of the heat storage tank 21 is input into the heat exchanger 22 by the heat storage pump 23 and the secondary side high temperature port 223 to exchange heat and release heat, and 43℃ cold water is discharged from the secondary side low temperature port 224 and stored in the bottom low temperature area of the heat storage tank 21; at this time, the 53℃ hot water enters the heat exchanger from the secondary side high temperature port, and the 41℃ cold water entering the heat exchanger from the primary side low temperature port is countercurrently exchanged, so that heat release is realized.

[0130] Through the above air source heat pump charging and releasing processes, the heat charging and releasing processes of countercurrent heat exchange are respectively constructed by using the heat exchanger, compared with the same direction heat exchange mode, the situation that energy cannot be exchanged in time, therefore, the countercurrent heat exchange mode adopted by the present application solves the technical defects that energy is excessively consumed during energy storage in the prior art.

[0131] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A control method for a sustainable renewable energy heating system, applied to a sustainable heating system comprising a direct heat supply cycle main loop (1) and a bidirectional heat charging and discharging module (2); characterized in that: The direct heat supply circulation main loop (1) is composed of a heater (11), a heat supply pipe network (12), a return pipe network (13) and a heat supply pump (14), which are connected in one direction in sequence to form a closed loop; The bidirectional heat charging and discharging module (2) is connected to the direct heat supply cycle main loop (1) via a heat charging path and a heat discharging path, wherein the heat charging path is connected from the heat supply pipe network (12) via the heat charging valve (4), the bidirectional heat charging and discharging module (2), and the regulating valve (3) to the suction end of the heat supply pump (14), and the heat discharging path is connected from the discharge end of the heat supply pump (14) via the heat discharging valve (5), the bidirectional heat charging and discharging module (2), and the regulating valve (3) to the heat supply pipe network (12), and the following conditions are satisfied: a. The heat charging path and the heat releasing path share the same bidirectional heat charging and releasing module (2) and the same regulating valve (3); b. The flow direction of water in the heat charging path is opposite to that of water in the heat releasing path; c. The heat charging valve (4) and the heat releasing valve (5) are independently arranged in different pipelines; The control method is executed by a PLC and includes the following steps: 1) Hot charging control process: Preset total return water temperature threshold T0; Obtain the total return water temperature T of the main circuit of the direct heat supply cycle (1) and the current power period status in real time; When the heater is in the off-peak period and the total return water temperature T> the preset threshold T0, execute: 1.

1. Activate the bidirectional charging and discharging module (2) to the charging mode; 1.

2. Open the heat charging valve (4) and close the heat releasing valve (5); 1.

3. Dynamically adjust the opening K1 of the regulating valve (3) to allow the water to flow along the heat charging path and allow the bidirectional heat charging and discharging module (2) to store heat; 1.

4. Continuously monitor the end conditions of hot charging and execute when any of the following conditions 1.4.1-1.4.3 are met: 1.4.

1. When the heating capacity of the bidirectional heat-charging and heat-discharging module (2) reaches 100%, close the heat-charging valve (4) and the regulating valve (3) to keep the bidirectional heat-charging and heat-discharging module (2) in standby mode; 1.4.

2. When the heater (11) enters the peak power period, close the heat charging valve (4), adjust the regulating valve (3) to a safe opening, and make the bidirectional heat charging and discharging module (2) enter the heat discharging control process in step 2) and enter the heat discharging standby state; 1.4.3, when T≤T0, the bidirectional charging and discharging heat module (2) is in the charging mode standby state; 2) Heat release control process: Preset the direct heat supply efficiency threshold η0 of the direct heat supply cycle main loop (1); Calculate the direct heat efficiency η of the main circuit of the direct heat cycle (1) in real time and obtain the current power period status; When the heater (11) is in the peak power period and the direct heat efficiency η is less than the direct heat efficiency threshold η0, the following is executed: 2.

1. Activate the bidirectional charging and discharging module (2) to the heat discharging mode; 2.

2. Open the heat release valve (5) and close the heat charging valve (4) to allow the water to flow along the heat release path; 2.

3. Dynamically adjust the opening K2 of the regulating valve (3) to enable the bidirectional heat charging and discharging module (2) to release the stored heat; 2.

4. Continuously monitor the end conditions of heat release and execute when any of the following conditions 2.4.1-2.4.3 are met: 2.4.

1. When the heat capacity of the bidirectional heat-charging and heat-discharging module (2) is reduced to 0%, the heat-discharging valve (5) and the regulating valve (3) are closed, and the bidirectional heat-charging and heat-discharging module (2) is kept in standby mode; 2.4.

2. When the heater (11) enters the off-peak period, the heat release valve (5) is closed and the regulating valve (3) is adjusted to a safe opening, so that the bidirectional heat charging and discharging module (2) enters the heat release control process of step 1) and heats up and waits; 2.4.

3. When η≥η0, the bidirectional charging and discharging heat module is in the heat discharging mode standby state.

2. The control method of the sustainable renewable energy heating system according to claim 1, characterized in that: The total return water temperature threshold T0 ranges from 41°C to 45°C.

3. The control method of the sustainable renewable energy heating system according to claim 1, characterized in that: The direct heat efficiency threshold η0 is the direct heat efficiency value determined based on the coefficient of performance COP and the integrated part-load performance coefficient IPLV specified in GB 19577-2024 "Energy Efficiency Limit Values ​​and Energy Efficiency Grades for Heat Pumps and Chillers".

4. The control method of the sustainable renewable energy heating system according to claim 1, characterized in that: The bidirectional heat charging and discharging module (2) is composed of a heat storage tank (21), a heat exchanger (22), a heat storage pump (23), a valve V1, a valve V2, a valve V3, a valve V4, a valve V5 and a valve V6; wherein, the high-temperature fluid port of the heat storage tank (21) is fluidically connected to the high-temperature port of the secondary side of the heat exchanger (22) through the valve V5, the low-temperature port of the secondary side of the heat exchanger (22) is fluidically connected to the low-temperature fluid port of the heat storage tank (21) through the valve V6, the suction end of the heat storage pump (23) is fluidically connected to the high-temperature fluid port through the valve V1, and the suction end of the heat storage pump (23) is also fluidically connected to the high-temperature fluid port through the valve V2. The heat storage pump (23) is connected to the low-temperature fluid port, the discharge end of the heat storage pump (23) is connected to the secondary-side high-temperature port through the valve V3 fluid, and the discharge end of the heat storage pump (23) is connected to the secondary-side low-temperature port through the valve V4 fluid; when the heat storage pump (23) is running, the valves V1, V3 and V6 are opened, and the valves V2, V4 and V5 are closed, the heat release mode of the two-way heat charging and discharging module (2) is activated; when the heat storage pump (23) is running, the valves V1, V3 and V6 are closed, and the valves V2, V4 and V5 are opened, the heat charging mode of the two-way heat charging and discharging module (2) is activated.

5. The control method of the sustainable renewable energy heating system according to claim 1, characterized in that: The heat exchanger (22) comprises at least one plate heat exchanger.

6. The control method of the sustainable renewable energy heating system according to claim 1, characterized in that: The heat release valve (5) and the heat charging valve (4) are interlocked through PLC.

7. The control method of the sustainable renewable energy heating system according to claim 1, characterized in that: The adjustment of opening K1 and opening K2 both adopts PID control algorithm.

8. The control method of the sustainable renewable energy heating system according to claim 1, characterized in that: The regulating valve (3) is any one of an electric regulating valve, a pneumatic regulating valve and a hydraulic regulating valve.

9. A control device for a sustainable renewable energy heating system, characterized in that: include: The direct heat supply circulation main loop (1) is a closed loop formed by sequentially one-way connection of a heater (11), a heat supply pipe network (12), a return water pipe network (13) and a heat supply pump (14); The bidirectional heat charging and discharging module (2) is connected to the direct heat supply cycle main loop (1) via a heat charging path and a heat discharging path; wherein the heat charging path is connected from the heat supply pipe network via a heat charging valve (4), the bidirectional heat charging and discharging module (2), and a regulating valve (3) to the suction end of the heat supply pump (14); and the heat discharging path is connected from the discharge end of the heat supply pump (14) via a heat discharging valve (5), the bidirectional heat charging and discharging module (2), and a regulating valve (3) to the heat supply pipe network (12): A total return water temperature sensor (7) collects the total return water temperature T of the direct heat supply cycle main circuit (1) in real time; A heating efficiency calculator (8) for calculating the direct heating efficiency η of the direct heating cycle main loop (1) in real time; A power period identification module (9) for obtaining the peak and valley status of the power grid; A PLC (6) is connected to the total return water temperature sensor (7), the heating efficiency calculator (8) and the power period identification module (9); The PLC (6) is programmed to execute the control method according to claim 1.

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