CN110617546A

CN110617546A - Air source heat pump electric heat storage system and control method

Info

Publication number: CN110617546A
Application number: CN201810638694.XA
Authority: CN
Inventors: 邬志军
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-06-20
Filing date: 2018-06-20
Publication date: 2019-12-27

Abstract

The invention discloses an air source heat pump electric heat storage system and a control method thereof, the system comprises at least one air source heat pump, at least one integrated electric heat storage device, a plate exchanger, a primary side water pump and a secondary side water pump which are distributed on two sides of the plate exchanger, a circulating pipeline which enables water flow of the equipment to be communicated and supplies heat to the tail end, a cable used for supplying power to each equipment in the system, and a control system which controls the operation flow of the whole system, the integrated electric heat storage device integrates an electric heating device and the heat storage device into an integrated equipment, at least one of the air source heat pumps is a high-temperature air source heat pump, and the control system controls the air source heat pump electric heat storage system to be flexibly switched among various different operation modes. The invention reduces the number of the heat pumps by the integrated electric heat storage device, simplifies the system, reduces the initial investment of equipment, enhances the reliability of the system, reasonably utilizes clean energy, has small occupied area of the system and high system efficiency, can fully utilize off-peak electricity and has low operating cost.

Description

Air source heat pump electric heat storage system and control method

Technical Field

The invention relates to the technical field of heating, in particular to an air source heat pump electric heat storage system and a control method.

Background

Air source heat pump heating and heat storage heating are two electric heating modes which are widely applied at present. The air source heat pump has high manufacturing cost, occupies a large outdoor space, has noise pollution, has low heat efficiency when the ambient temperature is low, or cannot operate due to frosting of an outdoor evaporator, and influences the popularization of the air source heat pump. The electric heat storage heating is not affected by the ambient temperature, but the heat stored during the off-peak electricity period needs to be used all day long, so the electric power load is large, and the off-peak electricity price of each province and city is not cheap enough at present, so the heating cost of the electric heat storage is often higher. Obviously, if the air source heat pump and the electric heat storage are combined together, the air source heat pump and the electric heat storage are a better heating mode, but because the environment temperature is lower and the outlet water temperature is higher, the high compression ratio can cause the burning of a heat pump motor, so the outlet water temperature of the heat pump is generally not more than 55 ℃, so the heat pump heat storage system mentioned in the prior art generally adopts a low-temperature phase change medium, but the price of the phase change medium is high, and the system cost is increased. For example, the invention patent with the Chinese patent number of CN201510727615.9 and the publication number of 2018, 3 and 30 discloses an energy storage type air source heat pump heating system and an operation method thereof, namely, a phase change heat storage device is used for storing heat, and in the patent, the heat storage is realized only by a heat pump, so when the ambient temperature is reduced and the heat supply capacity of the heat pump is insufficient, the heat storage cannot be realized, or a larger heat pump needs to be selected to meet the heat storage requirement, thereby further increasing the initial investment; and only rely on the heat pump heat accumulation, when the heat pump breaks down, heat supply and heat accumulation can both stop, and the reliability of system is not high. The invention patent with Chinese patent number CN200910071271.5 and publication date of 2011, 5, month and 4 discloses a large energy storage type air source heat pump hot water unit, which only considers heat storage of a heat pump and does not adopt electric heat storage, and on the other hand, the system flow of the patent reflects that when heat is supplied, the heat pump is connected with the tail end through plate exchange, so that when the heat pump is required to directly supply heat, the water outlet temperature of the heat pump needs to be increased to offset the heat transfer temperature difference of the plate exchange, and the efficiency of the heat pump is reduced; the invention patent with Chinese patent number CN201710344792.8 and publication number 2017, 5 and 16 discloses a heat accumulating type electric boiler and air source heat pump combined heat supply device and a heat supply method.

It can be seen from the above patent that the existing combination of heat pump and electric heat storage has certain defects, mainly because of the characteristics of air source heat pump compressor and working medium, the temperature of the outlet water of the heat pump is about 50 degrees, and the temperature of the end water supply is 40-50 degrees or even higher, so the volume of the water heat storage is huge, and only phase change heat storage can be adopted. In the existing phase change heat storage, if a heater is directly inserted into a phase change medium for heating, the phase change medium is locally overheated and goes bad, so that an electric boiler is required to be added to heat water and then convey the water to a coil pipe in the phase change medium to realize phase change heat storage, and the system is complex and high in price.

Traditional water heat accumulation device is for preventing electric heater scale deposit and easy access, generally makes electric boiler with electric heater to separately be connected with heat accumulation device, if combine with heat pump system again, can cause the system complicacy, increase the cost, defect such as computer lab area is big hinders the popularization of this technique.

On the other hand, the current project of central electric heating is getting bigger and bigger, the required heat storage device is also big, in order to save the cost, the general heat storage device selects the open system, and separates the heat storage and electric heating device from the end plate. And the higher the outlet water temperature of the air source heat pump is, the lower the heat efficiency is, so if the air source heat pump is connected with the water tank during heat storage, when the tail end is heated, the outlet water temperature of the heat pump is increased to offset the heat exchange temperature difference of the plate exchange, and the tail end heating temperature can be met, thus the heat pump efficiency is reduced.

Disclosure of Invention

The invention aims to provide an air source heat pump electric heat storage system and a control method thereof, solves the problems that the prior air source heat pump and electric heat storage combined system cannot adopt water heat storage due to low outlet water temperature of a heat pump or a heat storage water tank is too large, the heat storage heat pump has low heat supply efficiency, the system is complex after an electric boiler and a heat storage device are separated, the occupied area is large and the like, and provides a control method under the equipment matching principle of the high-temperature air source heat pump heat storage system and the operation principle of ensuring the heat supply quality of a terminal load and the lowest operation cost.

The technical scheme adopted by the invention for solving the technical problems is as follows:

an air source heat pump electric heat storage system comprises at least one air source heat pump, at least one integrated electric heat storage device, a plate exchanger, a primary side water pump and a secondary side water pump which are distributed on two sides of the plate exchanger, a circulating pipeline which enables water flows of the equipment to be communicated and supplies heat to the tail end, cables which are used for supplying power to the equipment in the system, and a control system which controls the operation flow of the whole system, wherein the air source heat pump comprises:

the integrated electric heat storage device integrates the electric heating device and the heat storage device into an integrated device, and comprises a heat storage medium, an electric heating device, an upper water distributor and a lower water distributor; the heat storage medium is water; the integrated electric heat storage device can realize different operation modes of self heat storage of the electric heating device, heat storage of the heat pump, heat storage and heat supply of the integrated electric heat storage device, heat supply of the integrated electric heat storage device and combined heat supply of the integrated electric heat storage device and the heat pump;

at least one of the air source heat pumps is a high-temperature air source heat pump, the outlet water temperature of the high-temperature air source heat pump reaches above 60 ℃, and the high-temperature air source heat pump is connected with the integrated electric heat storage device on the primary side of the plate exchanger during heat storage to heat a heat storage medium to realize heat storage of the heat pump; when the high-temperature air source heat pump supplies heat, the electric valve of the control system is used for switching the connection between the high-temperature air source heat pump and the tail end of the secondary side of the plate exchanger, so that heat supply of the heat pump is realized;

and the control system controls the air source heat pump electric heat storage system to be flexibly switched among various different operation modes according to an operation principle of ensuring the lowest end load heat supply quality and operation cost.

Preferably, the air source heat pump electric heat storage system meets the end heat supply requirement by an air source heat pump and an integrated electric heat storage device together, preferably, the effective heat release amount of the air source heat pump accounts for 20% -80% of the design peak load, and the insufficient part is complemented by the heat release of the integrated electric heat storage device; when the air source heat pump and the integrated electric heat storage device supply heat together and still cannot meet the end requirement, the electric heating device in the integrated electric heat storage device is started to perform emergency heating.

Preferably, the number of the integrated electric energy storage devices is 1 or more; an upper water distributor and a lower water distributor are arranged in the integrated electric heat storage device, 1 to a plurality of groups of flange heaters are arranged between the lower water distributor and the bottom of the integrated electric heat storage device, and the flange heaters are connected and sealed with the outer wall of the integrated electric heat storage device through flanges; the heater is a flange type electric heater formed by fixing a plurality of groups of electric heating tubes on a flange, or the flange type electric heater is inserted into a heat pipe filled with a heat transfer medium to form a heat pipe type electric heater; the heat storage medium of the integrated electric heat storage device is water; when the heat pump is in a heat storage working condition, the high-temperature air source heat pump heats water, wherein the heat storage termination temperature is preferably 70 ℃; when the integrated electric heat storage device is in a self heat storage working condition, the heater heats water, wherein the heat storage termination temperature is preferably 85 ℃; when the integrated electric heat storage device is in a heat supply working condition, the upper water distributor pumps high-temperature water in the integrated electric heat storage device, the high-temperature water is conveyed to the plate through the primary side water pump to exchange heat with the secondary side tail end low-temperature return water to realize heat release and temperature reduction, and the preferable temperature is 45 degrees when the heat release is finished.

Preferably, the control system comprises an electric valve, a sensing element, a frequency converter, a power distribution cabinet and a system control cabinet, the control system automatically acquires control input parameters, external environment temperature and humidity and time-by-time electricity price data of each part of the system, controls the start and stop of equipment according to the change of the data and the operation principle of ensuring the heat supply quality of the tail end load and the lowest operation cost, switches the system flow and realizes various different operation modes.

Preferably, 4 electric valves are arranged at the water inlet and the water outlet of each high-temperature air source heat pump, specifically, an electric valve v1 and a v2 are arranged at the water outlet of each high-temperature air source heat pump, an electric valve v3 and a v4 are arranged at the water inlet of each high-temperature air source heat pump, when the high-temperature air source heat pump is in a heat storage working condition of the heat pump, the high-temperature air source heat pump is switched to a plate exchange primary side to be connected with a heat storage device, the electric valves v1 and v3 are opened, the electric valves v2 and v4 are; when the heat pump is in a heat supply working condition, the high-temperature air source heat pump is switched to the plate exchange secondary side to be connected with the tail end, the electric valves v2 and v4 are opened, the electric valves v1 and v3 are closed, and the heat pump and the integrated electric heat storage device are completely cut off;

because the 4 electric valves are arranged in front of each high-temperature air source heat pump, the operation is flexible, the system requirements can be controlled, 1 to more high-temperature air source heat pumps are selected for heat storage, or 1 to more high-temperature air source heat pumps are selected for heat supply, or part of high-temperature air source heat pumps are selected for heat storage, and part of high-temperature air source heat pumps are selected for heat storage;

when part of heat pumps do not participate in heat storage, an electric valve is respectively arranged at the water inlet and the water outlet of the part of heat pumps, and when the heat pumps run, the electric valves are opened; when the heat pump stops running, the electric valve is closed;

electrically operated valves v7 and v8 are sequentially arranged on a pipeline from a secondary side water outlet to a tail end water inlet of the plate exchanger;

electric valves v5 and v9 are arranged on pipelines from a main water inlet pipe to a tail end water outlet of the air source heat pump;

an electric valve v6 is arranged on a pipeline from the main water inlets of the air source heat pumps to the water inlet of the secondary side of the plate exchanger;

electric valves v10 are arranged on the main water outlet pipes of the air source heat pumps;

electric valves v11, v12 and v14 are arranged on a pipeline from a water outlet at the primary side of the plate exchange to a lower water distributor of the integrated electric heat storage device;

an electric valve v13 is arranged on a pipeline from a water inlet of the secondary side of the plate exchange to a water distributor on the integrated electric heat storage device.

Preferably, the air source heat pump is at least one high-temperature air source heat pump or a plurality of high-temperature air source heat pumps connected in parallel, wherein preferably, the high-temperature air source heat pump is a double-stage screw compression high-temperature air source heat pump, the refrigerant adopts R134a, and the outlet water temperature is 70 ℃; the high-temperature air source heat pump is connected with the plate exchange primary side heat storage device during heat storage and is connected with the tail end of the plate exchange secondary side during heat supply; preferably, the heat pump not involved in heat storage is a cheaper scroll compressor air source heat pump, or a two-stage screw compression high-temperature air source heat pump with a refrigerant of R22 is directly connected with the tail end to supply heat, so as to reduce the operation cost and reduce the manufacturing cost as much as possible.

The invention also provides a control method of the air source heat pump electric heat storage system, and as two different heat supply and heat storage devices of the air source heat pump and the integrated electric heat storage device are adopted, the control system can realize a heat storage mode, a heat supply mode and a heat storage and heat supply mode according to the operation principle of ensuring the lowest end load heat supply quality and operation cost; the heat storage mode comprises the working conditions of heat storage of a heat pump, self heat storage of an integrated electric heat storage device and combined heat storage of the heat pump and the integrated electric heat storage device; the heat supply mode comprises the working conditions of single heat supply of the integrated electric heat storage device, single heat supply of the heat pump and combined heat supply of the heat pump and the integrated electric heat storage device; the side heat storage and side heat supply mode comprises working conditions of self heat storage of the integrated electric heat storage device and heat supply of the heat pump, side heat storage of the integrated electric heat storage device and heat supply of the heat pump, and the user can select one or more working conditions to operate according to actual conditions.

Preferably, the heat storage mode is started when the following conditions are met, and the corresponding control method is as follows:

(1) when the operating cost of heat pump heat storage is low, and partial or all high-temperature air source heat pumps do not need to supply heat during the valley electricity period, a heat pump heat storage mode is adopted, at the moment, the high-temperature air source heat pumps are connected with a plate primary side heat storage medium through an electric valve switching device and are thoroughly separated from a plate secondary side heat exchange pipeline, at the moment, electric heating devices in the integrated electric heat storage devices are not started, low-temperature water in the integrated electric heat storage devices is pumped out from a lower water distributor by the heat storage water pumps and is conveyed to the high-temperature air source heat pumps, the high-temperature air source heat pumps are used for heating the water temperature to 70 ℃, the heated high-temperature water returns to an upper water distributor of the integrated electric heat storage devices, and the high-temperature water is lower than the low-temperature water, so that the high-temperature water can be on the upper portion of the integrated electric heat storage devices under the action of the water distributors, the low-temperature water is continuously The temperature of all the integrated electric heat storage devices reaches the set heat storage temperature, wherein preferably, the heat storage termination temperature is 70 ℃, or the heat storage working condition of the heat pump is finished because the valley power time is finished or the control system sends a stop command;

(2) when the operation cost of the self-heat storage of the integrated electric heat storage device is low, the self-heat storage working condition of the integrated electric heat storage device is adopted, the heat pump does not store heat at the moment, an electric heater in the integrated electric heat storage device is started to heat a heat storage medium, and preferably, the temperature of the heat storage medium is heated to more than 85 ℃ through continuous heating; when the heat storage medium is heated to a set heat storage termination temperature, wherein the heat storage termination temperature is preferably 85 ℃, or the integrated electric heat storage device finishes the self heat storage working condition due to the end of the valley power time or the control system sending a stop command;

(3) because the heat storage temperature of the heat pump is low, the heat storage capacity of the integrated electric heat storage device is small under the heat storage working condition of the heat pump, when the operating cost of the heat pump is low and the heat storage capacity of the heat pump can not meet the heat supply requirement required under the set operating mode on the next day, the heat storage working condition of the heat pump can be preferentially adopted during the valley electricity, when the heat pump heats the low-temperature medium in the integrated electric heat storage device to the set heat storage temperature, preferably, after the temperature of the heat storage medium reaches 70 ℃, the heat pump stops heating the medium in the heat storage device, an electric heater in the integrated electric heat storage device is started to heat the heat storage medium to the set heat storage termination temperature, preferably, the temperature is 85 ℃ so as to increase the heat storage capacity and meet the heat supply requirement on the next day, at the moment, the temperature of all the heat storage devices reaches the set heat storage temperature, preferably, the heat storage termination temperature is 85 degrees, or the heat storage working condition of the heat pump is finished due to the end of the valley power time or the stop command sent by the control system.

Preferably, the heating mode is started when the following conditions are met, and the corresponding control method is as follows:

(1) when the single heat supply operation cost of the integrated electric heat storage device is low and the heat supply requirement of the tail end of the day can be independently met, the single heat supply working condition of the integrated electric heat storage device is adopted, at the moment, the control system stops all heat pumps and the electric heater from operating, the tail end low-temperature backwater is conveyed by the plate heat exchange secondary side water pump to enter the plate for heat exchange and exchanges heat with high-temperature water from the upper water distributor of the integrated electric heat storage device at the plate heat exchange primary side, the outlet water at the plate heat exchange secondary side is heated and then conveyed to the tail end for heat release, the outlet water at the plate heat exchange primary side is cooled and then conveyed to the lower water distributor of the integrated electric heat storage device by the heat release water pump, the low-temperature water is higher than the high-temperature water, so that the low-temperature water is in the lower part of the heat storage device under the action of the water distributor, the high-temperature water in, or the temperature difference of the water inlet and the water outlet of the integrated electric heat storage device is lower than a set value, or the control system sends a stop command, and the single heat supply working condition of the integrated electric heat storage device is finished;

(2) when the heat pump can independently meet the requirement of terminal heat supply, the air source heat pump electric heat storage system can operate the following working conditions under the setting of the control system:

firstly, when the integrated electric heat storage device does not participate in heat supply operation, a heat pump single heat supply working condition is adopted, at the moment, a control system switches part or all of heat pumps to a plate exchange secondary side to supply heat to a tail end, after the temperature of tail end low-temperature return water is raised to a designed heat supply temperature through the heat pumps, the tail end low-temperature return water is conveyed to the tail end through a secondary side heat supply pump to supply heat, and when the control system sends a stop command, the heat pump single heat supply working condition;

when the integrated electric heat storage device participates in heat supply operation, the integrated electric heat storage device can be selected to store heat and execute the single heat supply working condition of the integrated electric heat storage device in the electric power peak period or the period designated by a user, and the single heat supply working condition of the heat pump is switched to after the heat release of the integrated electric heat storage device is finished;

when the integrated electric heat storage device participates in heat supply operation, preferably, in order to reduce the outlet water temperature of the heat pump and improve the efficiency of the heat pump, the heat pump and the integrated electric heat storage device can be used for heating working conditions in a combined mode; at the moment, the control system starts corresponding heat pumps according to self-control setting, the tail-end low-temperature backwater is firstly raised to the set temperature through the heat pumps, the temperature can improve the efficiency of the heat pumps, and the requirement of reaching the tail-end heat supply after reheating through plate exchange can be met. The water heated by the heat pump enters the plate exchange secondary side inlet and exchanges heat with high-temperature water from a water distributor on the integrated electric heat storage device on the plate exchange primary side, the outlet water on the plate exchange secondary side is heated and then conveyed to the tail end to release heat, and the outlet water on the plate exchange primary side is cooled and then conveyed to a lower water distributor of the integrated electric heat storage device by a heat release water pump; when the control system sends a stop command, the heat pump single heat supply working condition is finished;

(3) when the heat pump can not independently meet the requirement of terminal heat supply, the air source heat pump electric heat storage system can operate the following working conditions under the setting of the control system:

firstly, when the heat pump and the integrated electric heat storage device supply heat to the tail end together to meet the requirement of tail end heat supply, the heat pump and the integrated electric heat storage device are adopted to supply heat under the working condition of combination; at the moment, the control system switches all heat pumps to a plate exchange secondary side to be connected with a tail end and starts the heat pumps in full quantity, low-temperature return water at the tail end is heated by the heat pumps firstly, but the low-temperature return water does not have enough heating capacity of the heat pumps and needs to enter an inlet of the plate exchange secondary side again to exchange heat with high-temperature water from a water distributor on the integrated electric heat storage device at the plate exchange primary side, outlet water at the plate exchange secondary side is heated to a set heat supply temperature by the plate exchange and then is conveyed to the tail end to release heat, outlet water at the plate exchange primary side is cooled and then is conveyed to a lower water distributor of the integrated electric heat storage device by a heat release water pump, and;

secondly, when the heat pump and the integrated electric heat storage device supply heat to the tail end together and cannot meet the heat supply requirement of the tail end, the electric heating is adopted to supplement the heat supply working condition; at this moment, the control system starts as described in the first point, and simultaneously, the electric heater in the integrated electric heat storage device is started to heat the heat storage medium, so that the heat supply capacity of the heat storage device is increased, and the tail end heat supply temperature reaches the design requirement.

Preferably, when the heat pump type heat pump system is in the following conditions, the heat storage and heat supply mode is started, wherein the heat storage and heat supply mode comprises the heat pump heat storage and heat supply working conditions, the integrated electric heat storage device self-heat storage + heat pump heat supply, and the integrated electric heat storage device heat storage and heat supply working conditions, and the corresponding control method comprises the following steps:

(1) during off-peak electricity, when the tail end has heat supply requirements, the operating cost of the heat pump is low, and part of high-temperature air source heat pumps do not need heat supply during off-peak electricity, the heat pump is adopted to supply heat while accumulating heat, at the moment, the high-temperature air source heat pump participating in heat accumulation executes the heat accumulation working condition of the heat pump, and the heat pump not participating in heat accumulation executes the single heat supply working condition of the heat pump;

(2) during off-peak electricity, when the tail end has a heat supply requirement, the heat pump directly supplies heat to the tail end because of the need, no abundant heat storage exists, and the tail end heat supply requirement can be met only by heat release of the integrated electric heat storage device in the next day, the integrated electric heat storage device is adopted to carry out the self-heat storage working condition and the heat pump supplies heat, at the moment, the integrated electric heat storage device carries out the self-heat storage working condition, and the heat pump is switched to a plate exchange secondary side to be connected with the tail end to carry out the heat pump;

(3) during off-peak electricity, when the tail end has a heat supply requirement and the heat pump cannot supply heat to the tail end, and the tail end heat supply requirement can be met only by heat release of the integrated electric heat storage device in the next day, an integrated electric heat storage device is adopted while heat storage is carried out, and at the moment, the control system starts the electric heating device in the heat storage device to heat the medium in the heat storage device while executing a single heat supply working condition of the integrated electric heat storage device;

during off-peak electricity, when the tail end has heat supply requirements, such as when a user of a residential project sleeps, the room temperature can be properly reduced, preferably, a heat pump intermittent heat storage method can be adopted, namely, during off-peak electricity, the heat pump is positioned on the plate exchange secondary side for directly supplying heat to the tail end for a period of time, a heat pump single heat supply working condition is executed, and after the tail end return water temperature rises to a design temperature and is stabilized for a period of time, part or all of the high-temperature air source heat pumps are switched to the plate exchange primary side for executing the heat pump heat storage working condition; if the heat accumulation volume of the integrated electric heat accumulation device is not enough during heat pump intermittent heat accumulation, the heat accumulation working condition of the integrated electric heat accumulation device can be executed during off-peak electricity after the heat pump heat accumulation working condition is ended, the heat accumulation temperature is further improved, the heat accumulation volume is increased, and the operation cost is fully reduced and the terminal heat supply requirement is ensured.

The invention has the beneficial effects that:

(1) when the heat supply load demand is maximum, the heat supply through the integrated electric heat storage device reduces the number of the heat pumps, simplifies the system and reduces the initial investment of the system.

(2) The integrated electric heat storage device integrates electric heating, heat storage and heat release, an independent electric boiler and a switching electric valve for heat storage and heat release conversion are eliminated, the system is simplified, the floor area of a heat pump and electric heat storage system is reduced, the manufacturing cost is reduced, and the heat efficiency of the system is improved;

(3) when the heat pump equipment fails or the heat pump efficiency is low or even the heat pump stops working in severe cold areas or the heat pump stops running due to power failure, the system water pump can be started through the diesel generator, the electricity storage equipment and the like, heat supply can still be ensured, the effect of uninterrupted heating in power failure is achieved, the reliability of the system is greatly improved, and the method has very important significance to the popularization of an electric heating system!

(4) The invention adopts at least one high-temperature air source heat pump for heat storage, thereby adopting integrated water heat storage to replace a phase change medium for heat storage, reducing the manufacturing cost of the system and improving the reliability of the system.

(5) The working state of the heat exchange pump is flexibly switched by the control system, and the control system switches the heat pump to the tail end to directly supply heat during heat supply; during heat storage, the control system switches the heat pump to the integrated electric heat storage device side to store heat for the integrated electric heat storage device; the heat pump can store heat and supply heat, and the outlet water temperature of the heat pump can be reduced and then heated by the integrated electric heat storage device during heat supply.

(6) Because the efficiency of the air source heat pump is higher than the system efficiency under partial load when the air source heat pump is fully opened, a control method that each heat pump is fully opened and fully closed can be adopted under the state of heat supply of a plurality of heat pumps, the tail end is preliminarily heated by the heat pump after low-temperature backwater, and then the tail end heat supply temperature is ensured by reheating through a heat storage device.

(7) When a traditional heat pump system defrosts in a severe cold area, the four-way valve turns to absorb heat from a pipeline system, and at the moment, the heat pump supplies cold to the tail end in winter, so that the tail end feels great influence comfortably. When the heat pump defrosting is carried out, the heat pump absorbs heat from the pipeline system to reduce the outlet water temperature of the heat pump, but the heat supply temperature of the tail end system can still be ensured after reheating through the plate exchange of the electric heat storage system, so that the reliability of the system is greatly improved

(8) The traditional heat pump system is low in temperature rise speed and heat supply temperature, and in buildings which supply heat for other than 24 hours such as office buildings, the tail end temperature can rise after the heat pump is started for a long time

(9) According to the specific conditions of the project, the quantity of the heat pumps and the integrated electric heat storage devices can be reasonably configured, the quantity of the heat pumps specifically comprises the quantity of high-temperature water heat pumps and the quantity of low-temperature water heat pumps, the heat pump and the refrigerant type with the highest efficiency can be selected according to the environmental conditions, such as a high-temperature screw air source heat pump, a high-temperature spiral air source heat pump, a normal-temperature heat pump, R134a, R22 and the like, and are reasonably matched and combined, further, the control system realizes several different operation modes of heat pump heat storage, integrated electric heat storage device self heat storage, integrated electric heat storage device single heat supply, heat pump and integrated electric heat storage device combined heat supply, heat pump heat storage and heat supply, integrated electric heat storage device self heat storage and heat supply and the like according to the operation principle that the end load heat supply quality and the, the optimal condition of system operation can be realized to the maximum extent, the operation efficiency of the whole system is improved, and the operation cost and initial investment of the system are reduced.

Drawings

Fig. 1 is a flow chart illustrating the operation of an air-source heat pump electric heat storage system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the control system of the present invention operating in different operating conditions.

Detailed Description

The invention is described in detail below by way of exemplary embodiments. It should be understood, however, that elements, structures and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

As shown in fig. 1, an air-source heat pump electrical heat storage system according to an embodiment of the present invention includes:

eight heat pumps, namely a first heat pump 1, a second heat pump 2, a third heat pump 3, a fourth heat pump 4, a fifth heat pump 5, a 6 th heat pump 6, a 7 th heat pump 7 and an eighth heat pump 8, wherein each heat pump is provided with 4 electric valves, specifically, an electric valve v1 and a v2 are arranged at a water outlet of each heat pump, and an electric valve v3 and a v4 are arranged at a water inlet of each heat pump (in the figure, only the positions of the four electric valves on the first heat pump 1 are marked, and the positions of the electric valves v1, v2, v3 and v4 of the rest heat pumps are the same as the marks, so as to ensure the simplicity of pictures, and no repeated marks are made); in the embodiment, the first heat pump 1, the second heat pump 2 and the third heat pump 3 are heat storage heat pumps, the 3 heat storage heat pumps can produce high-temperature water, the temperature of outlet water can reach 60-110 ℃, the remaining 5 heat pumps are conventional heat pumps, the conventional heat pumps can produce low-temperature water, and the temperature of outlet water is 35-55 ℃; in other embodiments, the air source heat pump and the integrated electric heat storage device can be reasonably matched and combined according to specific conditions of projects, and the reasonable proportion of the high-temperature air source heat pump can be determined;

the integrated electric heat storage device 11, in the embodiment, the heat storage medium of the integrated electric heat storage device 11 is water, and the electric heating and heat storage device are integrated, so that the floor area of the system is saved;

the plate heat exchanger 12, the plate heat exchanger 12 is used for supplying heat at the tail end; the heat release water pump 10 is positioned on a pipeline between the plate heat exchanger 12 and the integrated electric heat storage device 11, high-temperature outlet water of the integrated electric heat storage device 11 enters the plate heat exchanger 12 through the heat release water pump 10 to complete heat exchange, and low-temperature water after heat release flows back to the integrated electric heat storage device 11 through the electric valve v 14;

the heat storage water pump 9 can convey the high-temperature outlet water of the 3 heat storage heat pumps to the integrated electric heat storage device 11, and heat the water in the integrated electric heat storage device 11;

a hot water supply pump 13, wherein the hot water supply pump 13 is arranged on the tail end circulating pipeline;

control system, control system is including setting up a plurality of motorised valves in the circulating line, sensing components and parts, the converter, switch board and system control cabinet, figure 1 shows the specific overall arrangement of a plurality of motorised valves in this embodiment, control system is according to guaranteeing that terminal load heat supply quality and the minimum operation principle of working costs, can realize heat pump heat storage, integrative electric heat storage device self-heat accumulation, heat pump and integrative electric heat storage device joint heat accumulation, integrative electric heat storage device list heat supply, heat pump and integrative electric heat storage device joint heat supply, heat pump limit heat accumulation while heat supply, integrative electric heat storage device limit heat accumulation while heat supply, several kinds of different mode of operation of integration electric heat storage device self-heat accumulation + heat pump heat supply.

Next, the operation conditions of the respective operating conditions will be further described with respect to the present embodiment.

(1) The heat storage working condition of the heat pump is as follows:

when the operating cost of the heat pump is low and part or all of the heat pumps do not need to supply heat during the valley electricity, the heat pump heat storage working condition is adopted.

In this embodiment, the control system controls 3 heat storage heat pumps, namely the first heat pump 1, the second heat pump 2 and the third heat pump 3, to be started, the remaining 5 conventional heat pumps are not started, the electric valves v1, v2, v3 and v4 of each conventional heat pump are all closed, the electric valves v1 and v3 of each heat storage heat pump are opened, v2 and v4 are closed, the electric valves v5, v8, v9 and v10 in a system pipeline are closed, and a tail end heat supply system is isolated; the electric valve v14 arranged at the water inlet on the primary side of the plate heat exchanger 12 is closed, the electric valve v7 arranged at the water outlet on the secondary side of the plate heat exchanger 12 is closed, and the water flow between the primary side and the secondary side of the plate heat exchanger 12 is blocked; the low-temperature water flowing out of the integrated electric heat storage device 11 passes through the electric valves v12 and v11, is conveyed by the heat storage water pump 9 to enter the 3 heat storage heat pumps through the electric valve v3 arranged at the water inlet of the first heat pump 1, the second heat pump 2 and the third heat pump 3 respectively, is heated to the highest water outlet temperature of the heat storage heat pumps (60-110 ℃, when different heat storage heat pumps are adopted, the highest water outlet temperatures are different), then flows out of the electric valves v1 arranged at the water outlet of the first heat pump 1, the second heat pump 2 and the third heat pump 3 respectively, and enters the integrated electric heat storage device 11 through the electric valve v13 to heat the heat storage medium in the integrated electric heat storage heat pumps; this operation is stopped when the temperature in the integrated electrical storage device 11 reaches a first set temperature, which is preferably 70 degrees celsius, or the end of the off-peak power period, at which time the operation of the system is optimal.

(2) The integrated electric heat storage device has the self-heat storage working condition that:

when the operating cost of the integrated electric heat storage device is low, the integrated electric heat storage device is adopted to automatically store heat, the heat pump does not store heat at the moment, and an electric heating element in the integrated electric heat storage device is started to heat a heat storage medium.

In this embodiment, the control system controls eight heat pumps not to be started, and simultaneously closes the electric valves v1, v2, v3 and v4 of the water inlet and outlet of each heat pump, and closes other valves in the pipeline, at this time, the system is started only by the integrated electric heat storage device 11, the heat pumps do not participate in heat storage, the electric heating elements in the integrated electric heat storage device 11 are started to heat the heat storage medium, when the heat storage medium is heated to a second set temperature or the off-peak electricity time period is over, the integrated electric heat storage device is stopped from the heat storage working condition, wherein the second set temperature is preferably 90 degrees centigrade, and at this time, the operation effect of the system is optimal.

(3) The heat pump and the integrated electric heat storage device are combined to store heat:

when the operating cost of the heat pump is low and the heat storage capacity of the heat pump cannot meet the heat supply requirement of the next day, the heat pump and the integrated electric heat storage device are combined to store heat, at the moment, the heat pump heat storage mode is preferentially adopted, and after the heat pump heats the low-temperature medium in the integrated electric heat storage device to the set heat storage temperature, the electric heating element is started, the temperature of the heat storage medium is further increased, and the heat storage capacity is increased.

In this embodiment, the control system controls 3 heat storage heat pumps, namely the first heat pump 1, the second heat pump 2 and the third heat pump 3, to be started, the remaining 5 conventional heat pumps are not started, the electric valves v1, v2, v3 and v4 of each conventional heat pump are all closed, the electric valves v1 and v3 of each heat storage heat pump are opened, v2 and v4 are closed, the electric valves v5, v8, v9 and v10 in a system pipeline are closed, and a tail end heat supply system is isolated; the low-temperature water flowing out of the integrated electric heat storage device 11 passes through the electric valves v12 and v11, is conveyed by the heat storage water pump 9 to enter the 3 heat storage heat pumps through the electric valve v3 arranged at the water inlet of the first heat pump 1, the second heat pump 2 and the third heat pump 3 respectively, is heated to the highest water outlet temperature of the heat storage heat pumps (60-110 ℃, when different heat storage heat pumps are adopted, the highest water outlet temperatures are different), then flows out of the electric valves v1 arranged at the water outlet of the first heat pump 1, the second heat pump 2 and the third heat pump 3 respectively, and enters the integrated electric heat storage device 11 through the electric valve v13 to heat the heat storage medium in the integrated electric heat storage heat pumps; when the system detects that the heat storage medium is heated to a certain temperature by the heat storage heat pump, the electric heating element in the integrated electric heat storage device 11 is started to heat the heat storage medium again, so that the temperature of the heat storage medium is further increased, and the heat storage capacity is increased.

(4) The single heat supply operating mode of integrative electric heat storage device:

when integrative electric heat storage device working cost is lower and can independently satisfy terminal heat supply demand on the same day, adopt integrative electric heat storage device list heat supply operating mode, at this moment, control system is with whole heat pump short circuit, directly by the heat supply of integration electric heat storage device to terminal.

In the embodiment, the control system controls eight heat pumps to be not started, and simultaneously closes electric valves v1, v2, v3 and v4 of water inlets and water outlets of each heat pump, low-temperature return water at the tail end passes through the tail-end water supply pump 13, enters a secondary-side water inlet of the plate heat exchanger 12 through an electric valve v5 and an electric valve v6, is heated by the plate heat exchanger 12, and returns to a tail-end water inlet main pipe through an electric valve v7 and an electric valve v8 to realize heat supply to the tail end; at this time, the low-temperature water at the primary side water outlet of the plate heat exchanger 12 is conveyed to the integrated electric heat storage device 11 through the electric valve v14 to be heated, and the high-temperature water at the water outlet of the integrated electric heat storage device 11 is conveyed to the tail end through the heat release water pump 10 to release heat again.

In the above working conditions, the control system can control the heat release amount of the plate heat exchanger 12 and ensure the end heat supply quality by adjusting the variable frequency flow rate of the heat release water pump 10.

(5) The heat pump single heat supply working condition is as follows:

when the operating cost of the heat pump is low and the heat supply requirement at the tail end of the day can be independently met, the heat pump single heat supply working condition is adopted, at the moment, the control system switches part or all of the heat pumps to directly supply heat to the tail end, if different types of heat pumps exist, the heat pumps with high heat efficiency and low operating cost are switched firstly, and then the heat pumps with low heat exchange efficiency and high operating cost are switched.

In this embodiment, the control system controls the electric valve v1 arranged at the water outlet of each heat pump and the electric valve v3 arranged at the water inlet to be closed, correspondingly, the electric valve v2 arranged at the water outlet of each heat pump and the electric valve v4 arranged at the water inlet to be opened, the low-temperature return water at the tail end passes through the electric valves v9 on the main water inlet pipes of the plurality of heat pumps through the tail end heat supply water pump 13, respectively passes through the electric valves v4 arranged at the water inlet of each heat pump, is heated by the heat pumps, and then is collected to reach the main pipe of the tail end water inlet through the electric valves v10 on the main water outlet pipes of the plurality of heat pumps after being heated by the heat pumps, so as to complete.

In the above working conditions, the electric valves v1, v3, v6, v7 and v11 are closed, so the plate heat exchanger 12 is completely isolated and does not participate in supplying heat to the tail end, and at this time, the control system achieves the effect of ensuring the heat supply quality of the tail end by adjusting the number of heat supply units of the heat pump and the heat supply output.

(6) The heat pump and the integrated electric heat storage device are combined to supply heat:

when the heat accumulation of integrative electric heat storage device and the heat supply of heat pump all can not satisfy the heat supply demand on the same day, adopt heat pump and the joint heat supply operating mode of integration electric heat storage device, at this moment, the heat pump is wide open, and terminal return water is earlier through heat pump promotion temperature, then improves the water supply temperature to the settlement through integrative electric heat storage device with the temperature to terminal heat supply.

In this embodiment, the control system controls all eight heat pumps to be started, an electric valve v1 arranged at a water outlet of each heat pump and an electric valve v3 arranged at a water inlet of each heat pump are opened, correspondingly, an electric valve v2 arranged at a water outlet of each heat pump and an electric valve v4 arranged at a water inlet of each heat pump are closed, low-temperature return water at the tail end passes through the tail end hot water supply pump 13 and passes through electric valves v5 on a plurality of heat pump main water inlet pipes, then passes through electric valves v3 arranged at water inlets of each heat pump respectively, is heated by the heat pumps, passes through electric valves v1 arranged at water outlets of each heat pump, is collected to pass through a plurality of heat pump main water outlet pipes to an inlet of the plate heat exchanger 12, is heated again to a designed heat supply temperature by the plate heat exchanger 12, and then flows through v8 from an outlet of.

At this moment, the system keeps the full load operation of the heat pump by switching on and off the number of heat supply units of the heat pump under the regulation of the control system, reduces the water outlet temperature of the heat pump as far as possible so as to improve the COP of the heat pump, then adjusts the heat release quantity of the integrated electric heat storage device 11 by the heat release water pump 10 of the integrated electric heat storage device 11 in a frequency conversion mode to heat the hot water at the inlet of the plate heat exchanger 12, achieves the heat supply temperature required by the design, and ensures the end heat supply quality by the combined operation of the heat pump and the integrated electric heat storage device.

(7) Heat pump with heat storage and heat supply

When the heat pump is in a low-ebb electricity period, the operation cost of the heat pump is low, part of heat pumps do not need to supply heat to the tail end in the low-ebb electricity period, and the part of heat pumps can produce high-temperature water at 60-110 ℃, the heat pump is adopted to heat and supply heat simultaneously, at the moment, the control system switches the part of heat pumps to directly supply heat to the tail end, at the moment, part of heat pumps continue to operate and meet the requirement of the tail end for supplying heat, electric heating elements in the heat storage device are not started, the heat storage water pump pumps out low-temperature water in the integrated electric heat storage device and conveys the low-temperature water to the other part of heat pumps, the high-temperature water heated to 60-110 ℃ by the heat pumps returns to the integrated electric heat storage device to heat storage media in the integrated electric heat storage device, and when the heat storage media are heated to a; the first set temperature is preferably 70 ℃, and the operation effect of the system is optimal.

In the embodiment, the control system controls all eight heat pumps to be started, the electric valves v1 arranged at the water outlets and v3 arranged at the water inlets of the first heat pump 1, the second heat pump 2 and the third heat pump 3 are opened, correspondingly, the electric valves v2 arranged at the water outlets and the electric valves v4 arranged at the water inlets of the first heat pump 1, the second heat pump 2 and the third heat pump 3 are closed, the low-temperature water flowing out of the integrated electric heat storage device 11 passes through the electric valves v12 and v11, is conveyed by the heat storage water pump 9 to respectively enter the 3 heat storage heat pumps through the electric valves v3 arranged at the water inlets of the first heat pump 1, the second heat pump 2 and the third heat pump 3, is heated to the highest water outlet temperature of the heat storage heat pumps (60-110 degrees, when different heat storage heat pumps are adopted, the highest water outlet temperatures are different), and then respectively flows out of the v1 arranged at the water outlets of the first heat pump 1, the second heat pump 2 and the third heat pump 3, the electric valve v13 is used for entering the integrated electric heat storage device 11 to heat the heat storage medium therein;

the electric valves v1 and v3 arranged at the water outlets of the fourth heat pump 4, the fifth heat pump 5, the sixth heat pump 6, the seventh heat pump 7 and the eighth heat pump 8 are closed, correspondingly, the electric valves v2 and v4 arranged at the water inlets of the heat pumps are opened, the low-temperature return water at the tail end passes through the electric valves v9 on the heat pump main water inlet pipes through the tail end hot water supply pump 13 and then respectively passes through the electric valves v4 arranged at the water inlets of the heat pumps, after the low-temperature return water is heated by the heat pumps, the low-temperature return water at the tail end passes through the electric valves v 38932 on the heat pump main water inlet pipes and then is collected to the tail end water inlet main pipe through the electric valves v10 on the heat pump main water outlet pipes, and the heat supply.

(8) Integrated electric heat storage device capable of simultaneously storing heat and supplying heat

When the operation cost of the integrated electric heat storage device is low during off-peak electricity, the integrated electric heat storage device is used for simultaneously storing heat and supplying heat, the heat pump does not store heat, an electric heating element in the integrated electric heat storage device is started to heat a heat storage medium, the integrated electric heat storage device directly supplies heat to the tail end, and when the heat storage medium is heated to a second set temperature or the off-peak electricity time period is over, the integrated electric heat storage device stops simultaneously storing heat and supplying heat; the second set temperature is preferably 90 degrees centigrade, and at this time, the operation effect of the system is optimal.

In the embodiment, the control system controls eight heat pumps to be not started, meanwhile, electric valves v1, v2, v3 and v4 for closing water inlets and water outlets of each heat pump are opened, electric valves v5, v6, v7, v11 and v14 are opened, the remaining electric valves are closed, low-temperature return water at the tail end passes through the tail end water supply heat pump 13 and enters a secondary side water inlet of the plate heat exchanger 12 through an electric valve v5 and an electric valve v6, and returns to a tail end water inlet main pipe through an electric valve v7 and an electric valve v8 after being heated by the plate heat exchanger 12 to realize heat supply to the tail end; at this time, the low-temperature water at the primary side water outlet of the plate heat exchanger 12 is conveyed to the integrated electric heat storage device 11 through the electric valve v14 to be heated, and the high-temperature water at the water outlet of the integrated electric heat storage device 11 is conveyed to the tail end through the heat release water pump 10 to release heat again.

(9) Integrated working condition of self-heat storage and heat pump heat supply of electric heat storage device

During off-peak electricity, the operating cost of the heat pump is low and can only meet the heat supply requirement of the tail end, the heat supply amount of the heat pump cannot meet the heat supply requirement of the next day, and when heat is required to be stored, an integrated electric heat storage device heat storage and heat pump single heat supply working condition is adopted, at the moment, the control system controls all the heat pumps to directly supply heat to the tail end, an electric heating element in the integrated electric heat storage device is started to heat a heat storage medium, and when the heat storage medium is heated to a second set temperature or the off-peak electricity time period is over, the integrated electric heat storage device heat storage and heat pump single heat supply working condition is stopped; the second set temperature is preferably 90 degrees centigrade, and at this time, the operation effect of the system is optimal.

In this embodiment, the control system controls all eight heat pumps to start, the electric valve v1 arranged at the water outlet of each heat pump and the electric valve v3 arranged at the water inlet of each heat pump are closed, correspondingly, the electric valve v2 arranged at the water outlet of each heat pump and the electric valve v4 arranged at the water inlet of each heat pump are opened, the low-temperature return water at the tail end passes through the electric valves v9 on the main water inlet pipes of the plurality of heat pumps through the tail end water supply heat pump 13, respectively passes through the electric valves v4 arranged at the water inlet of each heat pump, is heated by the heat pumps, and then reaches the main pipe at the tail end water inlet through the electric valves v10 on the main water outlet pipes of the plurality of heat pumps after being heated by the heat pumps, so;

the rest electric valves in the pipeline are all closed, the integrated electric heat storage device 11 only stores heat and does not supply heat, and the electric heating elements in the integrated electric heat storage device 11 are started to heat the heat storage medium in the integrated electric heat storage device.

From the detailed description of the above embodiments, it can be seen that the salient features of the present invention are as follows:

as shown in fig. 2, the control system controls the heat pump to directly supply low-temperature water to the terminal and also to supply high-temperature water to the heat storage device for heat storage, and according to the operation principle that the terminal load heat supply quality and the operation cost are the lowest, different operation modes of heat pump heat storage, self heat storage of the integrated electric heat storage device, combined heat storage of the heat pump and the integrated electric heat storage device, single heat supply of the heat pump, combined heat supply of the heat pump and the integrated electric heat storage device, heat supply while heat storage of the heat pump, self heat storage of the integrated electric heat storage device and heat supply of the heat pump are realized.

It should be noted that, although the invention has been described in terms of the above-mentioned embodiments, there are many other embodiments of the invention. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended that all such changes and modifications be covered by the appended claims and their equivalents.

Claims

1. An air source heat pump electric heat storage system comprises at least one air source heat pump, at least one integrated electric heat storage device, a plate exchanger, a primary side water pump and a secondary side water pump which are distributed on two sides of the plate exchanger, a circulating pipeline which enables water flow of the equipment to be communicated and supplies heat to the tail end, cables which are used for supplying power to the equipment in the system, and a control system which controls the operation flow of the whole system, and is characterized in that:

2. The air-source heat pump electric heat storage system of claim 1, wherein the air-source heat pump electric heat storage system meets the end heat supply requirement by the air-source heat pump and the integrated electric heat storage device, preferably, the effective heat release amount of the air-source heat pump accounts for 20% -80% of the design peak load, and the insufficient amount is complemented by the heat release of the integrated electric heat storage device; when the air source heat pump and the integrated electric heat storage device supply heat together and still cannot meet the end requirement, the electric heating device in the integrated electric heat storage device is started to perform emergency heating.

3. The air-source heat pump electric heat storage system of claim 1, wherein the number of the integrated electric heat storage devices is 1 or more; an upper water distributor and a lower water distributor are arranged in the integrated electric heat storage device, 1 to a plurality of groups of flange heaters are arranged between the lower water distributor and the bottom of the integrated electric heat storage device, and the flange heaters are connected and sealed with the outer wall of the integrated electric heat storage device through flanges; the heater is a flange type electric heater formed by fixing a plurality of groups of electric heating tubes on a flange, or the flange type electric heater is inserted into a heat pipe filled with a heat transfer medium to form a heat pipe type electric heater; the heat storage medium of the integrated electric heat storage device is water; when the heat pump is in a heat storage working condition, the high-temperature air source heat pump heats water, wherein the heat storage termination temperature is preferably 70 ℃; when the integrated electric heat storage device is in a self heat storage working condition, the heater heats water, wherein the heat storage termination temperature is preferably 85 ℃; when the integrated electric heat storage device is in a heat supply working condition, the upper water distributor pumps high-temperature water in the integrated electric heat storage device, the high-temperature water is conveyed to the plate through the primary side water pump to exchange heat with the secondary side tail end low-temperature return water to realize heat release and temperature reduction, and the preferable temperature is 45 degrees when the heat release is finished.

4. The air-source heat pump electric heat storage system of claim 1, wherein the control system comprises an electric valve, a sensing component, a frequency converter, a power distribution cabinet and a system control cabinet, the control system automatically acquires control input parameters, external environment temperature and humidity and time-by-time electricity price data of each part of the system, controls equipment start and stop according to the change of the data and according to an operation principle of ensuring the heat supply quality of a terminal load and the lowest operation cost, switches a system flow and realizes various different operation modes.

5. The air-source heat pump electrical thermal storage system of claim 4, wherein:

the method comprises the following steps that 4 electric valves are arranged at the water inlet and the water outlet of each high-temperature air source heat pump, specifically, an electric valve v1 and a electric valve v2 are arranged at the water outlet of each high-temperature air source heat pump, an electric valve v3 and a electric valve v4 are arranged at the water inlet of each high-temperature air source heat pump, when the high-temperature air source heat pump is in a heat storage working condition of the heat pump, the high-temperature air source heat pump is switched to a plate exchange primary side to be connected with a heat storage device, electric valves v1 and v3 are opened; when the heat pump is in a heat supply working condition, the high-temperature air source heat pump is switched to the plate exchange secondary side to be connected with the tail end, the electric valves v2 and v4 are opened, the electric valves v1 and v3 are closed, and the heat pump and the integrated electric heat storage device are completely cut off;

6. The air-source heat pump electric heat storage system of claim 1, wherein the air-source heat pump is at least one high-temperature air-source heat pump or a plurality of high-temperature air-source heat pumps connected in parallel, wherein preferably, the high-temperature air-source heat pump is a two-stage screw compression high-temperature air-source heat pump, the refrigerant is R134a, and the outlet water temperature is 70 ℃; the high-temperature air source heat pump is connected with the plate exchange primary side heat storage device during heat storage and is connected with the tail end of the plate exchange secondary side during heat supply; preferably, the heat pump not involved in heat storage is a cheaper scroll compressor air source heat pump, or a two-stage screw compression high-temperature air source heat pump with a refrigerant of R22 is directly connected with the tail end to supply heat, so as to reduce the operation cost and reduce the manufacturing cost as much as possible.

7. A control method of an air source heat pump electric heat storage system is characterized in that two different heat supply and heat storage devices, namely an air source heat pump and an integrated electric heat storage device, are adopted, and the control system can realize a heat storage mode, a heat supply mode and a heat storage and heat supply mode according to an operation principle of ensuring the lowest end load heat supply quality and operation cost; the heat storage mode comprises the working conditions of heat storage of a heat pump, self heat storage of an integrated electric heat storage device and combined heat storage of the heat pump and the integrated electric heat storage device; the heat supply mode comprises the working conditions of single heat supply of the integrated electric heat storage device, single heat supply of the heat pump and combined heat supply of the heat pump and the integrated electric heat storage device; the side heat storage and side heat supply mode comprises working conditions of self heat storage of the integrated electric heat storage device and heat supply of the heat pump, side heat storage of the integrated electric heat storage device and heat supply of the heat pump, and the user can select one or more working conditions to operate according to actual conditions.

8. The control method of an air-source heat pump electric thermal storage system according to claim 7, wherein the thermal storage mode is activated when the following conditions prevail, and the respective control methods are as follows:

9. The control method of an air-source heat pump electric heat storage system according to claim 7, wherein the heating mode is activated when the following conditions are met, and the corresponding control method is as follows:

when the integrated electric heat storage device participates in heat supply operation, preferably, in order to reduce the outlet water temperature of the heat pump and improve the efficiency of the heat pump, the heat pump and the integrated electric heat storage device can be used for heating working conditions in a combined mode; at the moment, the control system opens corresponding heat pumps according to self-control setting, the tail end low-temperature backwater is firstly raised to a set temperature through the heat pumps, the temperature can improve the efficiency of the heat pumps and can meet the requirement that the tail end heat supply is achieved after the tail end low-temperature backwater is reheated through plate exchange, the water heated by the heat pumps enters the plate exchange secondary side inlet and exchanges heat with high-temperature water from a water distributor on the integrated electric heat storage device on the plate exchange primary side, the outlet water on the plate exchange secondary side is heated and then conveyed to the tail end for heat release, and the outlet water on the plate exchange primary side is cooled and then conveyed to a lower water distributor of the integrated electric heat storage device through; when the control system sends a stop command, the heat pump single heat supply working condition is finished;

10. The control method of the air-source heat pump electric heat storage system according to claim 7, wherein the heat storage while heat supply mode is started when the following conditions are met, the heat storage while heat supply mode comprises a heat pump heat storage while heat supply condition, an integrated electric heat storage device self-heat storage + heat pump heat supply, and an integrated electric heat storage device heat storage while heat supply condition, and the corresponding control method is as follows:

(4) during off-peak electricity, when the tail end has heat supply requirements, such as when a user of a residential project sleeps, the room temperature can be properly reduced, preferably, a heat pump intermittent heat storage method can be adopted, namely, during off-peak electricity, the heat pump is positioned on the plate exchange secondary side for directly supplying heat to the tail end for a period of time, a heat pump single heat supply working condition is executed, and after the tail end return water temperature rises to a design temperature and is stabilized for a period of time, part or all of the high-temperature air source heat pumps are switched to the plate exchange primary side for executing the heat pump heat storage working condition; if the heat accumulation volume of the integrated electric heat accumulation device is not enough during heat pump intermittent heat accumulation, the heat accumulation working condition of the integrated electric heat accumulation device can be executed during off-peak electricity after the heat pump heat accumulation working condition is ended, the heat accumulation temperature is further improved, the heat accumulation volume is increased, and the operation cost is fully reduced and the terminal heat supply requirement is ensured.