A control method of a multi-energy cooperative heating system

Abstract

The application discloses a kind of control methods of multi-energy collaborative heating system, it is related to heat exchange heating field.Therein, multi-energy collaborative heating system includes: water tank, its one side is equipped with water tank heat exchange loop;Biomass boiler, its one side is equipped with biomass boiler heat exchange loop;Heat exchanger is equipped between the water tank heat exchange loop and the biomass boiler heat exchange loop;Soil source heat pump and air source heat pump are connected with the water tank and form loop;The control method of multi-energy collaborative heating system is to preferentially use soil source heat pump, secondly, according to the priority order of outdoor environment temperature to determine the use of biomass boiler and air source heat pump.Compared with prior art, the beneficial effects of the present application are: combining production operation cost and the dynamic change of heat load, and setting the corresponding system dynamic control mode based on the characteristics of each device, thereby greatly solving the shortcomings of slow system feedback, low temperature control precision and large temperature fluctuation in traditional control method, and truly realizing the efficient compatibility of supply-demand matching and energy saving.

Description

Technical Field

[0001] This invention belongs to the field of heating, and specifically relates to a control method for a multi-energy coordinated heating system. Background Technology

[0002] In recent years, the use of renewable energy to replace conventional energy for clean heating has received increasing attention. In the promotion and application of clean heating projects, the use of air-source heat pumps and ground-source heat pumps is key to accelerating the "coal-to-electricity" project in northern my country. However, air-source heat pump heating is greatly affected by ambient temperature; its heating capacity and energy efficiency ratio decrease significantly as the temperature drops. Furthermore, it is affected by factors such as frost, making it impossible to guarantee heating effectiveness when relying solely on air-source heat pumps during periods of severe weather. While ground-source heat pumps offer more stable heating characteristics, the cost of buried pipes is high, and there is also the problem of soil temperature gradually decreasing due to the imbalance between heat intake and exhaust. In addition, biomass, as a relatively clean fuel, is playing an increasingly important role in the promotion of clean heating, especially in rural areas of northern China. However, the uneven distribution of biomass resources across regions means that relying solely on biomass energy for heating can lead to problems such as insufficient fuel supply, excessively large supply radius, and excessively high costs. In practical heating projects, for users with large heat load demands, constructing a multi-energy coordinated heating system that couples biomass boilers, ground source heat pumps, and air source heat pumps can solve the problem that a single type of renewable energy cannot meet the large-scale heating demand. For multi-energy coordinated heating systems, the control method plays a crucial role in energy savings. Currently, the control systems for multi-energy coordinated heating are simple to set up, often resulting in system lag, process mismatch, and other problems, leading to large temperature fluctuations, poor heating effects, and energy waste.

[0003] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0004] Details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects and advantages of the present application more readily apparent.

[0005] This invention provides a control method for a multi-energy coordinated heating system. It combines the dynamic changes in production and operation costs and heat load, and sets corresponding dynamic control modes for the system based on the characteristics of each device. This greatly solves the shortcomings of traditional control methods, such as slow system feedback, low temperature control accuracy, and large temperature fluctuations, and truly achieves efficient compatibility between supply and demand matching and energy saving.

[0006] This invention discloses a control method for a multi-energy coordinated heating system, the multi-energy coordinated heating system comprising:

[0007] A water tank, on one side of which there is a heat exchange circuit of the water tank;

[0008] A biomass boiler, on one side of which there is a heat exchange circuit of the biomass boiler;

[0009] A heat exchanger, arranged between the heat exchange circuit of the water tank and the heat exchange circuit of the biomass boiler;

[0010] A ground source heat pump and an air source heat pump, both of which are connected to the water tank and form a circuit;

[0011] The control method of the multi - energy collaborative heating system is: the ground source heat pump is the main heating heat source, and the biomass boiler and the air source heat pump are auxiliary heating heat sources;

[0012] Wherein, the current heating temperature is T; the target heating temperature is Tg; the critical temperature of the air source heat pump is Tc; the current outdoor temperature is Ta; there are set heating - up comparison parameters a and b (a < b), with the unit of degree Celsius per minute; there is set a monitoring time interval

[0016] , t, with the unit of minute;

[0013] The control method of the ground source heat pump is: when T < Tg, adjust the ground source heat pump to the maximum load, and calculate the heating - up rate △ ΔT within the time interval △ t;

[0014] The control methods of the biomass boiler and the air source heat pump are: when T < Tg, and after adjusting the ground source heat pump to the maximum load, if a < ΔT < b, and Ta < Tc, then adjust the biomass boiler to the maximum load; if a < ΔT < b, and Ta > Tc, then adjust the air source heat pump to the maximum load; if △ ΔT < a, then adjust both the biomass boiler and the air source heat pump to the maximum load.

[0015] In some embodiments, a is 0.15 °C / 15 minutes and b is 0.25 °C / 15 minutes. For residential heating, when the heating load increases, it should be required that the temperature rise reaches more than 1 degree Celsius within one hour, otherwise it will affect the comfort of the living environment; at the same time, if the heating - up rate is too slow, then when the heat load fluctuates greatly, there will be a situation of too long delay and adjustment oscillation, so the heating - up rate cannot be too low. Therefore, when the heating temperature is insufficient, adjust the load of the ground source heat pump, with 15 minutes as the temperature - measuring interval. If the temperature rise exceeds 0.25 °C, it means that adjusting the equipment load can meet the requirement of the heating - up rate. If not, it means that a new heat source needs to be started. If the heating - up rate within one hour is less than 0.6 degree Celsius, it means that the heat gap is large and two heat sources need to supply heat simultaneously.

[0016] In some embodiments, the control method of the multi-energy coordinated heating system is further provided with a temperature control accuracy δT;

[0017] The control method of the soil source heat pump further includes: if the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, dynamically adjust and reduce the load of the soil source heat pump.

[0018] The control method for the biomass boiler and the air source heat pump further includes: if the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, dynamically adjust and reduce the load of the biomass boiler and / or the air source heat pump.

[0019] In some implementations, the value of δT is in the range of 3-5℃.

[0020] In some embodiments, the multi-energy coordinated heating system further includes:

[0021] The heating pipeline is located at the top of the water tank;

[0022] The heat recovery pipeline is located at the bottom of the water tank;

[0023] The heating end of the soil source heat pump and the heating end of the air source heat pump are connected in parallel to the heating pipeline; the heat recovery ends of the soil source heat pump and the air source heat pump are connected in parallel to the heat recovery pipeline.

[0024] A temperature sensor is located below the heating pipe inside the water tank;

[0025] The buried pipe is connected to the evaporator of the soil source heat pump to form a circuit.

[0026] In some embodiments, the method for determining the critical temperature Tc of the air source heat pump is as follows:

[0027] The critical performance coefficient (COPc) of an air source heat pump is calculated using the following formula;

[0028]

[0029] Where Q is the required heating power, KW; COPc is the critical performance coefficient of the air source heat pump at the critical temperature; Ce is the electricity price, yuan / kWh; Cb is the unit price of biomass briquettes, yuan / kg; ηb is the heating efficiency of the biomass boiler; Hb is the calorific value of biomass briquettes, taken as 16720KJ / kg.

[0030] The significance of this formula is that when the critical performance coefficient of the air source heat pump is a certain value, at the current prices of biomass briquette fuel and electricity, the operating costs of the air source heat pump and the biomass boiler are equal when they generate the same amount of heat; according to the relationship between the performance coefficient of the air source heat pump and the outdoor ambient temperature, the critical temperature Tc corresponding to the critical performance coefficient COPc can be obtained.

[0031] In some embodiments, the following steps are included:

[0032] Step S1: Start the control system and set the target heating temperature Tg, temperature control accuracy δT, the critical temperature of the air source heat pump as Tc, heating-up comparison parameters a and b, and monitoring time interval △ t;

[0033] Step S2: Measure the current heating temperature T, compare it with Tg. If T > Tg, then execute Step S4; if T < Tg, then increase the load of the ground source heat pump and record the heating-up rate △ T, compare its relationship with the heating-up comparison parameters a and b; if △ T > b, then execute Step S3; if a < ΔT < b, execute Step S6; if ΔT < a, execute Step S13;

[0034] Step S3: Adjust the ground source heat pump to the maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute Step S4;

[0035] Step S4: Continuously monitor the heating temperature, record the temperature change every △ t △ T. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the ground source heat pump, record the heating temperature each time and execute Step S5 once;

[0036] Step S5: Based on the dynamic change of the heating temperature recorded in Step S4, judge the relationship between the current heating temperature T and the target heating temperature Tg; if T > Tg, then execute Step S4; if T < Tg, judge the state of the ground source heat pump. If it has not been adjusted to the maximum load, then execute Step S4; if the ground source heat pump has reached the maximum heating load, then execute S6;

[0037] Step S6: Judge the relationship between the current outdoor temperature Ta and the critical temperature Tc of the air source heat pump. If Ta < Tc, execute Step S7; if Ta > Tc, execute Step S10;

[0038] Step S7: Start the biomass boiler to the maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute Step S8;

[0039] Step S8: Continuously monitor the heating temperature. When the heating temperature exceeds the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the biomass boiler and record the current heating temperature T. Execute Step S9 every time the heating temperature is recorded;

[0040] Step S9: Based on the dynamic change of the heating temperature recorded in Step S8, judge the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T>Tg+δT, judge the working state of the biomass boiler. If the biomass boiler has been less than the minimum allowable load, turn off the biomass boiler and execute Step S4; if the biomass boiler has not been reduced to the minimum load, then execute Step S8; if Tg<T<Tg+δT, then execute Step S8; if T<Tg, judge the working state of the biomass boiler. If it has not been adjusted to the maximum load, then execute Step S8; if it has reached the maximum heating load, then execute S13;

[0041] Step S10: Turn on the air source heat pump to the maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute Step S11;

[0042] Step S11: Continuously monitor the heating temperature. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the air source heat pump. Record the heating temperature and execute Step S12 every time;

[0043] Step S12: Based on the dynamic change of the heating temperature recorded in Step S11, judge the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T>Tg+δT, judge the working state of the air source heat pump. If the air source heat pump has been less than the minimum allowable load, turn off the air source heat pump and execute Step S4; if the air source heat pump has not been reduced to the minimum load, then execute Step S11; if Tg<T<Tg+δT, then execute Step S11; if T<Tg, judge the working state of the air source heat pump. If it has not been adjusted to the maximum load, then execute Step S11; if it has reached the maximum heating load, then execute S13;

[0044] Step S13: Turn on the biomass boiler and the air source heat pump to the maximum load to raise the current heating temperature to the target heating temperature Tg, and then execute Step S14;

[0045] Step S14: Continuously monitor the heating temperature. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the equipment load. Under the condition of Ta>Tc, give priority to adjusting the load of the biomass boiler, otherwise give priority to adjusting the load of the air source heat pump. Record the heating temperature and execute Step S15 every time;

[0046] Step S15: Based on the dynamic change of the heating temperature recorded in step S14, determine the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T > Tg + δT, determine the working state of the biomass boiler. If the biomass boiler has been shut down while the air source heat pump has not been shut down, execute step S11; if the air source heat pump has been shut down while the biomass boiler has not been shut down, execute step S8; if both devices have been shut down, execute step S4; if neither of them has been shut down, then execute step S14; if Tg < T < Tg + δT, then execute step S14.

[0047] Based on the characteristics of the biomass boiler, air source heat pump and ground source heat pump, this method proposes a control method for a collaborative heating system. By combining parameters such as heating temperature, heating rate, and outdoor temperature, the operation scheduling of each heating device is determined. Compared with the traditional control method for a multi-energy collaborative heating system, this method has the following advantages:

[0048] 1. It can perform dynamic control based on the real-time changes of outdoor temperature and heating load, so as to maintain the matching of heat supply and demand as much as possible at all times, avoid the problems of insufficient heating and heat waste, and achieve significant energy conservation.

[0049] 2. The switching of the air source heat pump and the biomass boiler is based on the critical use temperature of the air source heat pump, and the system operation mode is reasonable.

[0050] 3. The concept of heating rate is proposed. By evaluating the magnitude of the heating rate, it is possible to quickly determine which devices need to be turned on under the current required heat load condition, so as to achieve a rapid response to the change of heat load.

[0051] 4. When a new device needs to be turned on, first turn the device to the maximum load to quickly reach the required heating temperature, and then perform dynamic regulation according to the actual heating temperature, thus avoiding the problem of slow heating speed. Brief Description of the Drawings

[0052] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0053] Figure 1 It is a schematic structural diagram of the system of the present invention.

[0054] Figure 2 It is a schematic logical diagram of the present invention.

[0055] Brief Description of the Drawings: Biomass boiler 1, heat exchanger 2, water tank 3, temperature sensor 4, ground source heat pump 5, air source heat pump 6, buried pipe 7. Detailed Embodiments

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described and illustrated 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. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0057] Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0058] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention may be combined with other embodiments without conflict.

[0059] Reference Figure 1 As shown, a control method for a multi-energy coordinated heating system is provided. The multi-energy coordinated heating system includes: a biomass boiler 1, a heat exchanger 2, a water tank 3, a temperature sensor 4, a soil source heat pump 5, an air source heat pump 6, and a buried pipe 7.

[0060] A biomass boiler 1 has a biomass boiler heat exchange circuit on one side; a water tank 3 has a water tank heat exchange circuit on one side; a heat exchanger 2 is connected between the water tank heat exchange circuit and the biomass boiler heat exchange circuit; a soil source heat pump 5 and an air source heat pump 6 are both connected to the water tank 3 and form a circuit; this control system combines the biomass boiler 1, the soil source heat pump 5, and the air source heat pump 6 to form a multi-source coordinated heating system.

[0061] The biomass boiler 1 is a biomass boiler, and the heat exchanger 2 is a plate heat exchanger; the water tank 3 adopts a box structure with good heat storage performance; the water outlet and inlet of the biomass boiler form a loop with the plate heat exchanger, and gate valves V1, V2 and V3 are arranged on the loop, and a circulating pump P1 is arranged on the branch of the water outlet; gate valves V4 and a circulating pump P2 are arranged on the loop formed by the plate heat exchanger and the water tank 3; a heat supply pipeline and a heat regeneration pipeline are respectively arranged at the upper and lower parts of the water tank 3; the heat supply ends of the ground source heat pump 5 and the air source heat pump 6 are connected in parallel to the heat supply pipeline; the heat regeneration ends of the ground source heat pump 5 and the air source heat pump 6 are connected in parallel to the heat regeneration pipeline; a temperature sensor is arranged below the heat supply pipeline in the water tank 3; the buried pipe 7 is connected to the evaporator of the ground source heat pump 5 and forms a loop.

[0062] Among them, the control method of the multi-energy collaborative heating system is: the ground source heat pump 5 is the main heating heat source, and the biomass boiler 1 and the air source heat pump 6 are auxiliary heating heat sources; the current heating temperature is T; the target heating temperature is Tg; the critical temperature of the air source heat pump is Tc; the current outdoor temperature is Ta; the heating comparison parameters a and b (a < b) are set, and the unit is degrees Celsius per minute; the monitoring time interval △ t is set, and the unit is minutes.

[0063] The control method of the ground source heat pump 5 is: when T < Tg, the ground source heat pump 5 is adjusted to the maximum load, and the interval time △ is calculated, and the heating rate △ ΔT within t.

[0064] The control methods of the biomass boiler 1 and the air source heat pump 6 are: when T < Tg, and after the ground source heat pump 5 is adjusted to the maximum load, if a < ΔT < b and Ta < Tc, the biomass boiler 1 is adjusted to the maximum load; if a < ΔT Tc, the air source heat pump 6 is adjusted to the maximum load; if ΔT < a, both the biomass boiler 1 and the air source heat pump 6 are adjusted to the maximum load.

[0065] The control method of the electric heater is: when the ground source heat pump 5, the biomass boiler 1 and the air source heat pump 6 are all working at the maximum load, and the current heating temperature T still fails to reach the target heating temperature Tg, the electric heater is turned on for auxiliary heating.

[0066] In some embodiments, a is 0.15 °C / 15 minutes and b is 0.25 °C / 15 minutes. A temperature control accuracy δT is also set in the control method of the multi-energy collaborative heating system.

[0067] For systems using biomass boilers, ground source heat pumps, and air source heat pumps, the heat load on heating users is typically large due to the use of three different heating devices, and the area served by these users is also relatively large, such as a residential building of about 10,000 square meters. For these types of heating users, a heating rate of about 1°C per hour is usually required.

[0068] To ensure timely system adjustments and avoid lag, the interval for temperature monitoring is set... △ t is set to 15 minutes. When the system adjusts the ground source heat pump to the maximum load, if the system heating rate is greater than 0.25℃ / 15 minutes, it means that the ground source heat pump alone can quickly heat up to the target heating temperature. Therefore, b is set to 0.25℃ / 15 minutes; correspondingly, a is set to 0.15℃ / 15 minutes.

[0069] In addition, setting the temperature control accuracy δT is to avoid shutting down the equipment directly after reaching the target heating temperature. Frequent start-ups and shutdowns are not only not conducive to energy saving, but will also affect the service life of the equipment. The temperature control accuracy δT can usually be set to about 3-5℃.

[0070] Furthermore, the control method for the soil source heat pump 5 further includes: if the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, dynamically adjusting and reducing the load of the soil source heat pump 5; the control method for the biomass boiler 1 and the air source heat pump 6 further includes: if the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, dynamically adjusting and reducing the load of the biomass boiler 1 and / or the air source heat pump 6; the control method for the electric heater further includes: if the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, dynamically adjusting and reducing the load of the electric heater.

[0071] The system also incorporates auxiliary heating with electric heating wires. When designing the system's equipment scale, the five coldest days were ignored, and the heating load at the sixth lowest daily temperature was used as the maximum load design. In actual operation, the electric heating wires are activated for auxiliary heating during the five coldest days. Although operating costs are relatively high during this period, the system's equipment size can be reduced, thus saving initial investment and making it more economical overall. When all three heating devices are operating at maximum load and still cannot meet the heating demand, the electric heating wires are activated for auxiliary heating. When the heating temperature T exceeds the sum of the target heating temperature Tg and the temperature control accuracy δT, the electric heating wires are deactivated, and dynamic monitoring is implemented.

[0072] Since air source heat pumps and biomass boilers have similar operating costs, both are used as auxiliary heat sources. However, it is still necessary to determine their priority relationship and start-up stage. The method for determining the critical temperature Tc of the air source heat pump is as follows:

[0073] Calculate the critical coefficient of performance COPc of the air source heat pump by the following formula;

[0074]

[0075] Q is the required heating power, in KW; COPc is the critical coefficient of performance of the air source heat pump at the critical temperature; Ce is the electricity price, in yuan / KWh; Cb is the unit price of the biomass briquette fuel, in yuan / Kg; ηb is the heating efficiency of the biomass boiler; Hb is the calorific value of the biomass briquette fuel, taking 16720 Kj / Kg;

[0076] The significance of this formula is that when the critical coefficient of performance of the air source heat pump is a certain value, at the current biomass briquette fuel price and electricity price, the operating costs of the air source heat pump and the biomass boiler are equal when generating the same amount of heat; according to the relationship between the coefficient of performance of the air source heat pump and the outdoor ambient temperature, the critical temperature Tc corresponding to this critical coefficient of performance COPc can be obtained. When the outdoor temperature Ta is lower than Tc, the operating cost required for the air source heat pump to generate the same amount of heat is higher than that of the biomass boiler. At this time, the biomass boiler is started for auxiliary heating, and vice versa, the air source heat pump is started for heating.

[0077] Refer to Figure 2 As shown, the complete entire control method specifically includes the following steps:

[0078] Step S1: Start the control system and set the target heating temperature Tg, the temperature control accuracy δT, the critical temperature of the air source heat pump as Tc, the heating-up comparison parameters a and b, and the monitoring time interval △ t;

[0079] Step S2: Measure the current heating temperature T, compare the relationship with Tg. If T>Tg, then execute Step S4; if T<Tg, then increase the load of the ground source heat pump and record the heating-up rate[[ID= / / ]] △ T, compare its relationship with the heating-up comparison parameters a and b; if △ T>b, then execute Step S3; if a<ΔT<b, execute Step S6; if ΔT<a, execute Step S13;

[0080] Step S3: Adjust the ground source heat pump to the maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute Step S4;

[0081] Step S4: Continuously monitor the heating temperature, record the temperature change △ T every time interval △ t. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the ground source heat pump, record the heating temperature each time and execute Step S5 once;

[0082] Step S5: Determine the relationship between the current heating temperature T and the target heating temperature Tg based on the dynamic change of the heating temperature recorded in Step S4; if T > Tg, execute Step S4; if T < Tg, determine the status of the ground-source heat pump. If it has not been adjusted to the maximum load, execute Step S4; if the ground-source heat pump has reached the maximum heating load, execute S6;

[0083] Step S6: Determine the relationship between the current outdoor temperature Ta and the critical temperature Tc of the air-source heat pump. If Ta < Tc, execute Step S7; if Ta > Tc, execute Step S10;

[0084] Step S7: Start the biomass boiler at maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute Step S8;

[0085] Step S8: Continuously monitor the heating temperature. When the heating temperature exceeds the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the biomass boiler and record the current heating temperature T. Execute Step S9 each time the heating temperature is recorded;

[0086] Step S9: Determine the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT based on the dynamic change of the heating temperature recorded in Step S8; if T > Tg + δT, determine the working status of the biomass boiler. If the biomass boiler has a load less than the minimum allowable load, turn off the biomass boiler and execute Step S4; if the biomass boiler has not been reduced to the minimum load, execute Step S8; if Tg < T < Tg + δT, execute Step S8; if T < Tg, determine the working status of the biomass boiler. If it has not been adjusted to the maximum load, execute Step S8; if it has reached the maximum heating load, execute S13;

[0087] Step S10: Start the air-source heat pump at maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute Step S11;

[0088] Step S11: Continuously monitor the heating temperature. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the air-source heat pump. Execute Step S12 each time the heating temperature is recorded;

[0089] Step S12: According to the dynamic change of the heating temperature recorded in step S11, determine the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T>Tg + δT, determine the working state of the air source heat pump. If the air source heat pump has been less than the minimum allowable load, turn off the air source heat pump and execute step S4; if the air source heat pump has not been reduced to the minimum load, then execute step S11; if Tg<T<Tg + δT, then execute step S11; if T<Tg, determine the working state of the air source heat pump. If it has not been adjusted to the maximum load, then execute step S11; if it is already at the maximum heating load, then execute S13;

[0090] Step S13: Start the biomass boiler and the air source heat pump to the maximum load to raise the current heating temperature to the target heating temperature Tg, and then execute step S14;

[0091] Step S14: Continuously monitor the heating temperature. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the equipment load. Under the condition of Ta>Tc, give priority to adjusting the load of the biomass boiler, otherwise give priority to adjusting the load of the air source heat pump. Record the heating temperature once and execute step S15 once;

[0092] Step S15: According to the dynamic change of the heating temperature recorded in step S14, determine the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T>Tg + δT, determine the working state of the biomass boiler. If the biomass boiler has been turned off and the air source heat pump has not been turned off, execute step S11; if the air source heat pump has been turned off and the biomass boiler has not been turned off, execute step S8; if both devices have been turned off, execute step S4; if neither of them has been turned off, then execute step S14; if Tg<T<Tg + δT, then execute step S14.

[0093] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a multi-energy coordinated heating system, characterized in that, The multi-energy collaborative heating system includes: A water tank, on one side of which there is a water tank heat exchange circuit; A biomass boiler, on one side of which there is a biomass boiler heat exchange circuit; A heat exchanger, provided between the water tank heat exchange circuit and the biomass boiler heat exchange circuit; A ground source heat pump and an air source heat pump, both of which are connected to the water tank and form a circuit; A heating pipeline, provided at the upper part of the water tank; A heat recovery pipeline, provided at the lower part of the water tank; The heating ends of the ground source heat pump and the air source heat pump are connected in parallel to the heating pipeline; the heat recovery ends of the ground source heat pump and the air source heat pump are connected in parallel to the heat recovery pipeline; A temperature sensor, provided below the heating pipeline in the water tank; A buried pipe, connected to the evaporator of the ground source heat pump and forming a circuit; The control method of the multi-energy collaborative heating system is as follows: Step S1: Start the control system and set the target heating temperature Tg, the temperature control accuracy δT, the critical temperature of the air source heat pump as Tc, the heating comparison parameters a and b, and the monitoring time interval Δt; Step S2: Measure the current heating temperature T, compare it with Tg. If T>Tg, execute step S4; if T<Tg, increase the load of the ground source heat pump, and record the heating rate ΔT, compare its relationship with the heating comparison parameters a and b; if ΔT>b, execute step S3; if a<ΔT<b, execute step S6; if ΔT<a, execute step S13; Step S3: Adjust the ground source heat pump to the maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute step S4; Step S4: Continuously monitor the heating temperature, record the temperature change ΔT every time interval Δt. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the ground source heat pump, record the heating temperature each time and execute step S5 once; Step S5: According to the dynamic change of the heating temperature recorded in step S4, judge the relationship between the current heating temperature T and the target heating temperature Tg; if T>Tg, execute step S4; if T<Tg, judge the state of the ground source heat pump. If it has not been adjusted to the maximum load, execute step S4; if the ground source heat pump has reached the maximum heating load, execute S6; Step S6: Judge the relationship between the current outdoor temperature Ta and the critical temperature Tc of the air source heat pump. If Ta<Tc, execute step S7; if Ta>Tc, execute step S10; Step S7: Start the biomass boiler to the maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute step S8; Step S8: Continuously monitor the heating temperature, adjust the load of the biomass boiler according to the real-time change of the current heating temperature T. When the heating temperature exceeds the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the biomass boiler and record the current heating temperature T, record the heating temperature each time and execute step S9 once; Step S9: Based on the dynamic change of the heating temperature recorded in Step S8, determine the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T > Tg + δT, determine the working state of the biomass boiler. If the biomass boiler has reached less than the minimum allowable load, shut down the biomass boiler and execute Step S4; if the biomass boiler has not been reduced to the minimum load, then execute Step S8; if Tg < T < Tg + δT, then execute Step S8; if T < Tg, determine the working state of the biomass boiler. If it has not been adjusted to the maximum load, then execute Step S8; if it has reached the maximum heating load, then execute S13; Step S10: Start the air source heat pump to the maximum load to raise the current heating temperature T to the target heating temperature Tg, and then execute Step S11; Step S11: Continuously monitor the heating temperature. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the load of the air source heat pump, and execute Step S12 every time the heating temperature is recorded once; Step S12: Based on the dynamic change of the heating temperature recorded in Step S11, determine the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T > Tg + δT, determine the working state of the air source heat pump. If the air source heat pump has reached less than the minimum allowable load, shut down the air source heat pump and execute Step S4; if the air source heat pump has not been reduced to the minimum load, then execute Step S11; if Tg < T < Tg + δT, then execute Step S11; if T < Tg, determine the working state of the air source heat pump. If it has not been adjusted to the maximum load, then execute Step S11; if it has reached the maximum heating load, then execute S13; Step S13: Start the biomass boiler and the air source heat pump to the maximum load to raise the current heating temperature to the target heating temperature Tg, and then execute Step S14; Step S14: Continuously monitor the heating temperature. If the current heating temperature T is greater than the sum of the target heating temperature Tg and the temperature control accuracy δT, adjust the equipment load. Under the condition of Ta > Tc, preferentially adjust the load of the biomass boiler, otherwise preferentially adjust the load of the air source heat pump, and execute Step S15 every time the heating temperature is recorded once; Step S15: Based on the dynamic change of the heating temperature recorded in Step S14, determine the relationship between the current heating temperature T and the sum of the target heating temperature Tg and the temperature control accuracy δT; if T > Tg + δT, determine the working state of the biomass boiler. If the biomass boiler has been shut down while the air source heat pump has not been shut down, execute Step S11; if the air source heat pump has been shut down while the biomass boiler has not been shut down, execute Step S8; if both devices have been shut down, execute Step S4; if neither of them has been shut down, then execute Step S14; if Tg < T < Tg + δT, then execute Step S14.

2. The control method for the multi-energy coordinated heating system according to claim 1, characterized in that, a is 0.15 °C / 15 minutes, and b is 0.25 °C / 15 minutes.

3. The control method for the multi-energy coordinated heating system according to claim 1, characterized in that, The value range of δT is 3 - 5 °C.

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