Solar heating device
Technical Field
The invention belongs to the field of solar heat supply, and particularly relates to a solar heat supply device.
Background
In recent years, as people have more and more demands for heating of domestic hot water, heating and the like, solar energy is widely applied to various heat supply demands as a clean renewable energy source. The solar heating device is used for converting solar energy into heat energy, so that the part of the heat energy can be applied to required occasions.
At present, the existing solar heating device (as shown in fig. 10) mainly includes a heat collector 30, a water storage tank 40, an auxiliary heat source 50, a water pump, a control device, and the like. The working principle is as follows: the water pump enables water to circulate between the heat collector 30 and the water storage tank 40, and when the water temperature at the top end of the heat collector 30 is a plurality of degrees higher than the water temperature at the bottom of the water storage tank 40, the control device starts the water pump to enable water to circularly flow between the heat collector 30 and the water storage tank 40; when the water temperature at the top end of the heat collector 30 is lower than the water temperature at the bottom of the water storage tank 40, the control device starts the auxiliary heat source 50 to heat the water in the water storage tank 40, and the heated water is pressurized by the water pump from the water storage tank 40 and is sent to a user for heating and then returns to the water storage tank 40.
However, although the existing solar heating device can meet the heating requirement to a certain extent, it still has more defects. For example, in the conventional solar heating apparatus, the circulating medium between the heat collector 30 and the water storage tank 40 generally uses water as a heat transfer medium, the working temperature range is narrow, and a corresponding water treatment system and equipment are required, so that the cost is high and the thermal efficiency is low; in addition, the auxiliary heat source 50 in the existing solar heating device directly heats the water in the water storage tank 40, so that the electric energy is wasted; in addition, the existing solar heating device cannot adjust heat supply, so that the existing solar heating device cannot meet normal heat supply requirements in real time under the conditions of insufficient illumination intensity and the like.
In view of the shortcomings of the prior art, those skilled in the art would like to find a solar heating device that can meet the heating requirement in real time, so that the solar heating device can meet the supply of the required heat energy under any weather conditions.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide a solar heating device which can meet the heating requirement in real time, so that the solar heating device can meet the supply of required heat energy under any weather condition.
In view of this, the present invention provides a solar heating apparatus, comprising: the solar collector who connects gradually, first heat exchanger, heat storage water tank and concurrent heating device to and the entry linkage is between first heat exchanger and heat storage water tank, the exit linkage is at the pipeline between heat storage water tank and concurrent heating device, wherein, first heat exchanger and concurrent heating device correspond the entry of connecting the outer net and the export of outer net respectively, thereby make solar heating device be formed with the open loop mode of operation at least in order to the outer net heat supply, the open loop mode of operation includes:
open loop mode one: when the solar heat collector is in a heat absorption state and the collected heat is larger than the heat required by the outer net, the outer net backwater firstly enters the first heat exchanger, exchanges heat with a heat-conducting medium in the solar heat collector and then supplies heat to the outer net through the heat storage water tank and the pipeline, and when the temperature value in the heat storage water tank reaches the upper limit, the outer net backwater supplies heat to the outer net through the first heat exchanger and the pipeline;
and (2) open loop mode two: when the solar heat collector is in a heat absorption state and the collected heat is less than the heat required by the outer net, the backwater of the outer net sequentially passes through the first heat exchanger and the heat storage water tank to supply heat to the outer net;
and (3) an open loop mode III: when the solar heat collector is in a non-heat absorption state and the temperature of the heat storage water tank is higher than the temperature required by the external grid, the external grid backwater directly supplies heat to the external grid through the heat storage water tank;
and (4) an open loop mode IV: when the solar heat collector is in a non-heat absorption state and the temperature of the heat storage water tank is lower than the temperature required by the external grid, the external grid backwater supplies heat to the external grid after passing through the heat storage water tank and the heat supplementing device.
Further, solar heating device still includes the second heat exchanger of parallelly connected on connecting the pipeline between heat storage water tank and the concurrent heating device, and the second heat exchanger links to each other with first heat exchanger and concurrent heating device to make solar heating device still be formed with closed loop operation mode, closed loop operation mode includes:
in the closed-loop mode one: when the solar heat collector is in a heat absorption state and the collected heat is larger than the heat required by the outer net, the primary side backwater of the second heat exchanger firstly enters the first heat exchanger, exchanges heat with the solar heat collector, then sequentially flows through the heat storage water tank and the pipeline and then flows back to the primary side of the second heat exchanger, and when the temperature value in the heat storage water tank reaches an upper limit, the primary side backwater of the second heat exchanger flows back to the primary side of the second heat exchanger through the first heat exchanger and the pipeline; the secondary side return water of the second heat exchanger directly supplies heat to an external network after passing through the secondary side of the second heat exchanger;
and a second closed-loop mode: when the solar heat collector is in a heat absorption state and the collected heat is less than the heat required by the outer net, the return water at the primary side of the second heat exchanger flows back to the primary side of the second heat exchanger through the first heat exchanger and the heat storage water tank in sequence; the secondary side return water of the second heat exchanger directly supplies heat to an external network after passing through the secondary side of the second heat exchanger;
and a closed-loop mode III: when the solar heat collector is in a non-heat absorption state and the temperature of the heat storage water tank is higher than the temperature required by the external power grid, the return water at the primary side of the second heat exchanger directly flows through the heat storage water tank and then flows back to the primary side of the second heat exchanger; the secondary side return water of the second heat exchanger directly supplies heat to an external network after passing through the secondary side of the second heat exchanger;
and a closed-loop mode four: when the solar heat collector is in a non-heat absorption state and the temperature of the heat storage water tank is lower than the temperature required by the outer net, the water of the outer net is returned or supplemented to directly supply heat to the outer net after passing through the heat supplementing device.
Furthermore, an outlet of the solar heat collector is connected with a primary side inlet of the first heat exchanger, a primary side outlet of the first heat exchanger is connected with an inlet of the solar heat collector, a secondary side outlet of the first heat exchanger is simultaneously connected with an inlet of the heat storage water tank and an inlet of the pipeline, an outlet of the water storage tank is simultaneously connected with an outlet of the pipeline, a primary side inlet of the second heat exchanger, a secondary side inlet of the second heat exchanger and an inlet of the heat supplementing device, a primary side outlet of the second heat exchanger is simultaneously connected with a secondary side inlet of the first heat exchanger and an inlet of the outer net, a secondary side outlet of the second heat exchanger is connected with an inlet of the heat supplementing device, and an outlet of the heat supplementing device is connected with an outlet of the outer.
Further, the solar heating apparatus further includes a switching valve assembly including first and second switching valves disposed at secondary side outlets and secondary side inlets of the first heat exchanger, third and fourth switching valves disposed at inlets and outlets of the heat storage water tank, fifth and sixth switching valves disposed at inlets and outlets of the heat supplement apparatus, a seventh switching valve disposed on the pipe, an eighth switching valve disposed between the first and second switching valves and selectively connected to the first heat exchanger, a ninth switching valve disposed between the fifth and sixth switching valves and selectively connected to the heat supplement apparatus, and a nineteenth switching valve disposed between an outlet and an inlet of the external grid, wherein,
in the open-loop mode, the fifth switch valve, the sixth switch valve, the eighth switch valve and the nineteenth switch valve are closed, and the other switch valves are opened; when the temperature value in the heat storage water tank reaches the upper limit, the third switch valve, the fourth switch valve, the fifth switch valve, the sixth switch valve, the eighth switch valve and the nineteenth switch valve are closed, and the other switch valves are opened;
in the open-loop mode two, the fifth switch valve, the sixth switch valve, the seventh switch valve, the eighth switch valve and the nineteenth switch valve are closed, and the other switch valves are opened;
in the open-loop mode III, the first switch valve, the second switch valve, the fifth switch valve, the sixth switch valve, the seventh switch valve and the nineteenth switch valve are closed, and the other switch valves are opened;
in the open-loop mode four, the first switching valve, the second switching valve, the seventh switching valve, the ninth switching valve, and the nineteenth switching valve are closed, and the remaining switching valves are opened.
Further, the switch valve component also comprises a tenth switch valve and an eleventh switch valve which are arranged at the primary side inlet and the primary side outlet of the second heat exchanger, and are arranged at the secondary side inlet of the second heat exchanger, a twelfth switching valve and a thirteenth switching valve at secondary side outlets, a fourteenth switching valve disposed between the second switching valve and the eleventh switching valve, a fifteenth switching valve disposed between the eleventh switching valve and the nineteenth switching valve, a sixteenth switching valve disposed between the twelfth switching valve and the thirteenth switching valve and adapted to turn on the secondary side of the second heat exchanger, a seventeenth switching valve disposed between the tenth switching valve and the twelfth switching valve and adapted to form mutually independent return paths for the primary side and the secondary side of the second heat exchanger, and an eighteenth switching valve adapted to communicate the external water replenishing apparatus and the heat replenishing apparatus, wherein,
in closed loop mode: the fifth switch valve, the sixth switch valve, the eighth switch valve, the fifteenth switch valve, the sixteenth switch valve and the seventeenth switch valve are closed, and the other valves are opened; when the temperature value in the heat storage water tank reaches the upper limit, the third switch valve, the fourth switch valve, the fifth switch valve, the sixth switch valve, the eighth switch valve, the fifteenth switch valve, the sixteenth switch valve and the seventeenth switch valve are closed, and the other switch valves are opened;
in the closed-loop mode two: the fifth switch valve, the sixth switch valve, the seventh switch valve, the eighth switch valve, the fifteenth switch valve, the sixteenth switch valve and the seventeenth switch valve are closed, and the rest valves are opened;
in the closed-loop mode three: the first switch valve, the second switch valve, the fifth switch valve, the sixth switch valve, the seventh switch valve, the fifteenth switch valve, the sixteenth switch valve and the seventeenth switch valve are closed, and the other valves are opened;
in the closed-loop mode four: and the fifth switch valve, the sixth switch valve, the sixteenth switch valve and the eighteenth switch valve are opened, and the rest switch valves are closed.
Further, the first heat exchanger is an oil-water plate type heat exchanger, and the heat conducting medium in the solar heat collector is heat conducting oil.
Further, the heat supplementing device is connected to the pipeline close to the outlet of the outer net.
Further, the solar heating device also comprises a first sensor for detecting the water temperature in the first heat exchanger, a second sensor for detecting the water temperature in the hot water storage tank, and a controller which is simultaneously connected with the first sensor, the second sensor and the control valve component.
Further, the solar heat collector is provided in plurality in parallel with the first heat exchanger.
Further, the solar heat collector is a flat-plate solar heat collector and/or a trough type solar heat collector and/or a vacuum tube solar heat collector.
When the solar heat supply device is used, the angle of the solar heat collector can be automatically adjusted and the self circulation heat supply mode can be switched according to the conditions of the solar altitude angle, the intensity of illumination intensity, the cloudy and sunny weather and the like, so that the solar heat supply device can effectively meet the heat supply requirement in real time without being limited by the external environmental influence. Compared with the prior art, the solar heating device mainly has the following advantages:
1) the solar heating device has multiple operation modes, including an open-loop operation mode and a closed-loop operation mode, different operation modes can be flexibly switched to adapt to different external environments according to requirements, and the closed-loop mode is favorable for balancing water circulation in the solar heating device and regulating heat supply;
2) according to the solar heat supply device, the first heat exchanger adopts the oil-water plate type heat exchanger, and the solar heat collector adopts heat conducting oil as a heat carrier, so that more heat collected by the solar heat collector can be transferred to the first heat exchanger more quickly, and the conversion and transfer efficiency of heat energy is greatly improved;
3) according to the solar heating device, the heat supplementing device is connected to the pipeline close to the outer net, so that the heat quantity required by the outer net and the heat quantity generated by the heat supplementing device are realized, and the phenomenon of energy waste is avoided;
4) the solar heat collector in the solar heat supply device can be arranged in parallel with the first heat exchanger, so that the device can be applied to the requirement of large-area centralized heat supply.
Drawings
In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.
Fig. 1 shows a schematic construction of a solar heating apparatus according to the present invention;
fig. 2 is an operational diagram of a solar heating apparatus according to the present invention operating in an open loop mode;
FIG. 3 is a schematic diagram of the operation of the solar heating apparatus according to the present invention in the open loop mode two;
fig. 4 is an operation principle diagram of the solar heating apparatus according to the present invention operating in the open loop mode three;
fig. 5 is an operational principle diagram of the solar heating apparatus according to the present invention operating in the open loop mode four;
figure 6 is an operational principle diagram of the solar heating apparatus according to the present invention operating in a closed-loop mode;
FIG. 7 is an operational schematic diagram of the solar heating apparatus according to the present invention operating in a closed loop mode two;
fig. 8 is an operational schematic diagram of a solar heating apparatus according to the present invention operating in a closed-loop mode three;
fig. 9 is an operational schematic diagram of a solar heating apparatus according to the present invention operating in a closed-loop mode four;
fig. 10 is a schematic structural view of a solar heating apparatus in the prior art.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.
Fig. 1 shows a schematic structural view of a solar heating apparatus provided according to the present invention. As shown in fig. 1, the apparatus includes: the solar energy heat collector 100, the first heat exchanger 200, the heat storage water tank 300, the heat supplementing device 400 and the pipeline 600 with an inlet connected between the first heat exchanger 200 and the heat storage water tank 300 and an outlet connected between the heat storage water tank 300 and the heat supplementing device 400 are connected in sequence. Wherein, the first heat exchanger 200 and the heat compensating device 400 are respectively and correspondingly connected with an inlet of an external network and an outlet of the external network, so that the solar heating device is at least formed with an open-loop operation mode to supply heat to the external network, and the open-loop operation mode comprises:
open loop mode one: when the solar heat collector is in a heat absorption state and the collected heat is greater than the heat required by the outer net, the outer net backwater firstly enters the first heat exchanger 200, exchanges heat with the heat-conducting medium in the solar heat collector 100 and then supplies heat to the outer net through the heat storage water tank 300 and the pipeline 600, and when the temperature value in the heat storage water tank 300 reaches the upper limit, the outer net backwater supplies heat to the outer net through the first heat exchanger 200 and the pipeline 600;
and (2) open loop mode two: when the solar heat collector is in a heat absorption state and the collected heat is less than the heat required by the outer net, the outer net backwater sequentially passes through the first heat exchanger 200 and the heat storage water tank 300 to supply heat to the outer net;
and (3) an open loop mode III: when the solar heat collector is in a non-heat absorption state and the temperature of the heat storage water tank is higher than the temperature required by the external grid, the external grid backwater directly supplies heat to the external grid through the heat storage water tank 300;
and (4) an open loop mode IV: when the solar thermal collector is in a non-heat absorption state and the temperature of the heat storage water tank 300 is lower than the temperature required by the external grid, the external grid backwater supplies heat to the external grid after passing through the heat storage water tank 300 and the heat supplementing device 400.
When the solar heat supply device is used, the self circulation heat supply mode can be automatically switched according to the conditions of the intensity of external illumination, the cloudy and sunny weather and the like, so that the solar heat supply device can effectively meet the heat supply requirement in real time without being limited by the influence of the external environment.
In a preferred embodiment, the solar heating apparatus further includes a second heat exchanger 500 connected in parallel to a pipe connecting the hot water storage tank 300 and the supplementary heating apparatus 400, and the second heat exchanger 500 is connected to both the first heat exchanger 200 and the supplementary heating apparatus 400, so that the solar heating apparatus is further formed with a closed-loop operation mode including:
in the closed-loop mode one: when the solar thermal collector is in a heat absorption state and the collected heat is larger than the heat required by the outer net, the primary side backwater of the second heat exchanger 500 firstly enters the first heat exchanger 200, exchanges heat with the solar thermal collector 100, then sequentially passes through the heat storage water tank 300 and the pipeline 600 and then flows back to the primary side of the second heat exchanger 500, and when the temperature value in the heat storage water tank 300 reaches the upper limit, the primary side backwater of the second heat exchanger 500 flows back to the primary side of the second heat exchanger 500 through the first heat exchanger 200 and the pipeline 600; secondary side return water of the second heat exchanger 500 directly supplies heat to an external network after passing through the secondary side of the second heat exchanger 500;
and a second closed-loop mode: when the solar heat collector is in a heat absorption state and the collected heat is less than the heat required by the outer net, the primary side return water of the second heat exchanger 500 sequentially flows back to the primary side of the second heat exchanger 500 through the first heat exchanger 200 and the heat storage water tank 300; secondary side return water of the second heat exchanger 500 directly supplies heat to an external network after passing through the secondary side of the second heat exchanger 500;
and a closed-loop mode III: when the solar thermal collector 100 is in a non-heat absorption state and the temperature of the heat storage water tank 300 is higher than the temperature required by the external grid, the primary side return water of the second heat exchanger 500 directly flows through the heat storage water tank 300 and then flows back to the primary side of the second heat exchanger 500; secondary side return water of the second heat exchanger 500 directly supplies heat to an external network after passing through the secondary side of the second heat exchanger 500;
and a closed-loop mode four: when the solar thermal collector is in a non-heat absorption state and the temperature of the heat storage water tank 300 is lower than the temperature required by the external grid, the external grid returns water or supplies water to the external grid directly after passing through the heat supplementing device 400.
The closed loop mode of the invention is beneficial to the balance of water circulation in the solar heating device and the adjustment of heating.
The concrete connection structure, the working principle and the function of the solar heating apparatus according to the present invention in different operation modes will be described in detail below.
One, connection structure
According to the present invention, as shown in fig. 1, an outlet of a solar heat collector is connected to a primary side inlet of a first heat exchanger 200, a primary side outlet of the first heat exchanger 200 is connected to an inlet of a solar heat collector 100, a secondary side outlet of the first heat exchanger 200 is connected to an inlet of a heat storage water tank 300 and an inlet of a pipeline 600, an outlet of the heat storage water tank 300 is connected to an outlet of the pipeline 600, a primary side inlet of a second heat exchanger 500, a secondary side inlet of the second heat exchanger 500 and an inlet of an external network, a primary side outlet of the second heat exchanger 500 is connected to a secondary side inlet of the first heat exchanger 200 and an inlet of the external network, a secondary side outlet of the second heat exchanger 500 is connected to an inlet of the external network, and an outlet of the external network 400 is connected to an outlet of the external network.
Accordingly, as shown in fig. 1, the solar heating apparatus further includes a switching valve assembly including first and second switching valves 1 and 2 disposed at secondary side outlets, secondary side inlets of the first heat exchanger 200, third and fourth switching valves 3 and 4 disposed at inlets and outlets of the hot-water storage tank 300, fifth and sixth switching valves 5 and 6 disposed at inlets and outlets of the supplementary heating apparatus 400, a seventh switching valve 7 disposed on the pipe 600, an eighth switching valve 8 disposed between the first and second switching valves 1 and 2 and selectively accessing the first heat exchanger 200, a ninth switching valve 9 disposed between the fifth and sixth switching valves 5 and 6 and selectively accessing the supplementary heating apparatus, and a nineteenth switching valve 19 disposed between an outlet and an inlet of the outer net.
Further, as shown in fig. 1, the switching valve assembly further includes a tenth switching valve 10 and an eleventh switching valve 11 provided at the primary side inlet and the primary side outlet of the second heat exchanger 500, a twelfth switching valve 12 and a thirteenth switching valve 13 provided at the secondary side inlet and the secondary side outlet of the second heat exchanger 500, a fourteenth switching valve 14 provided between the second switching valve 2 and the eleventh switching valve 11, a fifteenth switching valve 15 provided between the eleventh switching valve 11 and the nineteenth switching valve 19, a sixteenth switching valve 16 provided between the twelfth switching valve 12 and the thirteenth switching valve 13 for turning on the secondary side of the second heat exchanger 500, a seventeenth switching valve 17 provided between the tenth switching valve 10 and the twelfth switching valve 12 for forming the primary side and the secondary side of the second heat exchanger 500 into mutually independent return paths, and an eighteenth switching valve 18 for communicating the external water replenishing means 700 with the heat replenishing means 400.
Second, the working principle and action
Referring to fig. 1 and 2, in the open-loop mode, the solar collector 100 is in a heat absorption state and the collected heat is greater than the heat required by the external grid, that is, the illumination is sufficient, the fifth switch valve 5, the sixth switch valve 6, the eighth switch valve 8 and the nineteenth switch valve 19 are closed, and the rest of the switch valves are opened. At this time, the solar collector 100 collects more heat energy, and this mode enables the return water of the external grid to supply heat to the external grid through the heat storage water tank 300 and the pipeline 600 after passing through the first heat exchanger 200, so that the heat energy can be supplied to the external grid more quickly and sufficiently, which greatly improves the heat supply efficiency.
When the temperature value in the hot water storage tank 300 reaches the upper limit, the third switch valve 3, the fourth switch valve 4, the fifth switch valve 5, the sixth switch valve 6, the eighth switch valve 8, and the nineteenth switch valve 19 are closed, and the remaining switch valves are opened. At this time, since the temperature in the heat storage water tank 300 reaches the upper limit value, in order to protect the safe use of the heat storage water tank 300, the external grid backwater is controlled to directly supply heat to the external grid through the pipeline 600 after the heat exchange is performed by the first heat exchanger 200.
Referring to fig. 1 and 3, in the second open-loop mode, when the solar collector 100 is in a heat absorption state and the collected heat is less than the heat required by the external grid, that is, the light intensity is weaker than that in the first open-loop mode, the fifth switching valve 5, the sixth switching valve 6, the seventh switching valve 7, the eighth switching valve 8 and the nineteenth switching valve 19 are closed, and the remaining switching valves are opened. At this time, since the temperature of the external grid return water continuously passing through the pipeline 600 after heat exchange by the first heat exchanger 200 does not meet the required temperature of the external grid, the pipeline 600 is disconnected, so that the external grid return water directly supplies heat to the external grid through the heat storage water tank 300 after heat exchange by the first heat exchanger 200.
Referring to fig. 1 and 4, in the open-loop mode three, the solar thermal collector is in a non-heat-absorbing state, the temperature of the hot water storage tank is higher than the temperature required by the external grid, the first switch valve 1, the second switch valve 2, the fifth switch valve 5, the sixth switch valve 6, the seventh switch valve 7 and the nineteenth switch valve 19 are closed, and the remaining switch valves are opened. At this time, since the solar heat collector 100 has no heat absorption, so that it cannot exchange heat with the first heat exchanger 200, in this mode, the external grid backwater supplies heat to the external grid only through the hot water storage tank 300.
Referring to fig. 1 and 5, in the open-loop mode four, the solar thermal collector is in a non-heat absorption state and the temperature of the hot water storage tank 300 is lower than the temperature required by the external grid, the first switch valve 1, the second switch valve 2, the seventh switch valve 7, the ninth switch valve 9 and the nineteenth switch valve 19 are closed, and the remaining switch valves are opened. At this time, since the temperature of the return water of the external grid passing through the heat storage water tank 300 cannot meet the required temperature of the external grid, the heat supplementing device 400 needs to be connected to heat the return water of the external grid.
In the closed-loop mode, as shown in fig. 1 and 6, as follows: when the solar heat collector 100 is in a heat absorption state and the collected heat is greater than the heat required by the external grid, that is, the illumination is sufficient, the fifth switch valve 5, the sixth switch valve 6, the eighth switch valve 8, the fifteenth switch valve 15, the sixteenth switch valve 16 and the seventeenth switch valve 17 are closed, and the rest valves are opened. At this time, the solar heat collector 100 collects more heat energy, and in this mode, the primary-side return water of the second heat exchanger 500 flows back to the primary side of the second heat exchanger 500 through the heat storage water tank 300 and the pipeline 600 after passing through the first heat exchanger 200, so that the heat energy can be supplied to the secondary grid more quickly and sufficiently, and the heat supply efficiency is greatly improved. And the secondary side return water of the second heat exchanger 500 can directly supply heat to the external network after passing through the secondary side of the second heat exchanger 500.
When the temperature value in the hot water storage tank 300 reaches the upper limit, the third switch valve 3, the fourth switch valve 4, the fifth switch valve 5, the sixth switch valve 6, the eighth switch valve 8, the fifteenth switch valve 15, the sixteenth switch valve 16, and the seventeenth switch valve 17 are closed, and the remaining switch valves are opened. At this time, since the temperature in the hot water storage tank 300 reaches the upper limit value, in order to protect the safe use of the hot water storage tank 300, the primary side return water of the second heat exchanger 200 is controlled to directly flow back to the primary side of the second heat exchanger 200 through the pipeline 600 after being subjected to heat exchange by the first heat exchanger 200, so as to heat the secondary network; and the secondary side return water of the second heat exchanger 500 can directly supply heat to the external network after passing through the secondary side of the second heat exchanger 500.
Referring to fig. 1 and 7, in the second closed-loop mode, the solar collector 100 is in a heat absorption state and the collected heat is less than the heat required by the external grid, that is, the light intensity is weaker than that in the first closed-loop mode, the fifth switch valve 5, the sixth switch valve 6, the seventh switch valve 7, the eighth switch valve 8, the fifteenth switch valve 15, the sixteenth switch valve 16 and the seventeenth switch valve 17 are closed, and the rest valves are opened. At this time, since the temperature of the primary-side return water of the second heat exchanger 500, which is continuously passed through the pipeline 600 after heat exchange by the first heat exchanger 200, does not meet the required temperature of the secondary grid, the pipeline 600 is disconnected, so that the primary-side return water of the second heat exchanger 500 is directly supplied with heat to the secondary grid through the heat storage water tank 300 after heat exchange by the first heat exchanger 200, and the secondary-side return water of the second heat exchanger 500 is directly supplied with heat to the external grid after passing through the secondary side of the second heat exchanger 500.
Referring to fig. 1 and 8, in the third closed-loop mode, the solar thermal collector is in a non-heat absorption state and the temperature of the hot water storage tank is higher than the temperature required by the external grid, the first switch valve 1, the second switch valve 2, the fifth switch valve 5, the sixth switch valve 6, the seventh switch valve 7, the fifteenth switch valve 15, the sixteenth switch valve 16 and the seventeenth switch valve 17 are closed, and the rest valves are opened. At this time, since the solar thermal collector 100 has no heat absorption, it cannot exchange heat with the first heat exchanger 200, and therefore, in this mode, the primary-side return water of the second heat exchanger 500 supplies heat to the secondary grid only through the heat storage water tank 300; and the secondary side return water of the second heat exchanger 500 directly supplies heat to the external network after passing through the secondary side of the second heat exchanger 500.
Referring to fig. 1 and 9, in the fourth closed-loop mode, the solar thermal collector is in a non-heat absorption state and the temperature of the hot water storage tank 300 is lower than the temperature required by the external grid, the fifth switch valve 5, the sixth switch valve 6, the sixteenth switch valve 16 and the eighteenth switch valve 18 are opened, and the rest of the switch valves are closed. At this time, since the temperature of the primary-side return water passing through the second heat exchanger 500 of the heat storage water tank 300 cannot meet the required temperature for the secondary grid and the external grid, the second heat exchanger 500 and the heat storage water tank 300 are disconnected to allow the external grid return water or the supplemented water to directly pass through the heat supplementing device 400 and then supply heat to the external grid.
In a preferred embodiment, the first heat exchanger 200 is an oil-water plate heat exchanger, and the solar collector 100 uses heat conducting oil as a heat carrier, so that the heat collected by the solar collector can be more and faster transferred to the first heat exchanger, thereby greatly improving the conversion and transmission efficiency of the heat energy. Also preferably, the second heat exchanger 500 is a water-water plate heat exchanger.
Preferably, the solar heat collector 100 may be provided in plurality in parallel with the first heat exchanger 200, that is, a plurality of solar heat collectors 100 are connected in parallel with the first heat exchanger 200, so that the solar heat supply apparatus of the present invention can be applied to the requirement of large-area central heat supply.
Further preferably, the solar thermal collector 100 may be a flat-plate solar thermal collector, a trough-type solar thermal collector, or a vacuum tube solar thermal collector, or may be a hybrid solar thermal collector according to specific needs.
In another preferred embodiment, the heat compensating device 400 is connected to a pipeline close to the outlet of the outer net, so as to realize how much heat is needed by the outer net and how much heat is generated by the heat compensating device 400, thereby avoiding the phenomenon of energy waste;
according to the present invention, the solar heating apparatus further includes a first sensor for sensing the temperature of water in the first heat exchanger 200 and a second sensor for sensing the temperature of water in the hot-water storage tank, and a controller simultaneously connected to the first sensor, the second sensor and the control valve assembly. Preferably, the first sensor and the second sensor transmit corresponding temperature signals to the controller, and the controller determines the operation mode of the solar heating device according to the difference value of the temperature signals so as to further control the opening and closing of the switch valve assembly, thereby realizing the automatic heating of the solar heating device.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.