CN116642277B - Energy storage defrosting device for heat recovery of gas boiler - Google Patents

Abstract

The invention provides an energy storage defrosting device for heat recovery of a gas boiler, which comprises the gas boiler, a two-stage energy storage device, an outdoor defrosting coil pipe, an electric control valve, an antifreezing water pump, an antifreezing water pipe, a reverse circulation defrosting pipe, a heat user, an indoor heat exchanger, a compressor, a gas-liquid separator, an outdoor heat exchanger, an M1 electric three-way valve and an M2 electric three-way valve; in the defrosting process, the energy storage defrosting device does not need the air source heat pump unit to defrost by reversely absorbing the heat in the room of the heat user, but defrost by the heat source of the two-stage energy storage device, so that the indoor temperature is ensured not to fluctuate, the loss of a valve can be reduced, and the service life of the compressor is prolonged.

Description

Energy storage defrost device for gas boiler heat recovery

Technical field

The present invention relates to the field of heating technology, and in particular to an energy storage defrosting device for heat recovery of gas boilers.

Background technique

The air source heat pump is an energy-saving device that uses high-level energy to flow heat from a low-level heat source to a high-level heat source. However, the air source heat pump is easily affected by temperature and humidity. In a low-temperature environment, the heat production of the air source heat pump unit decreases and cannot meet the indoor load demand. Therefore, in order to ensure the stability of heating supply and the energy saving of the heat pump system, it needs to be coupled with a gas boiler to share the indoor load.

The flue gas produced by the combustion of gas boilers is directly discharged into the atmosphere after treatment, which will cause some heat loss. If working in a low temperature and high humidity environment, frost will appear on the surface of the outdoor evaporator in the air source heat pump unit. At this time, the air source heat pump needs to perform reverse cycle defrosting. This method will not only consume indoor heat, but also cause the indoor temperature to drop. Larger fluctuations affect user comfort; and frequent changes in valve direction will also affect the life of the heat pump system.

Therefore, it is necessary to make full use of the exhaust gas heat of the gas boiler to defrost the air source heat pump to improve energy utilization while ensuring the thermal comfort of users.

Contents of the invention

The purpose of the invention is to collect the waste gas heat discharged from the combustion of the gas boiler, and at the same time use the waste gas heat to defrost the air source heat pump to ensure the efficient operation of the air source heat pump in a low temperature environment and save operating costs.

In order to achieve the above technical objectives, the present invention adopts the following technical solutions: an energy storage defrosting device for gas boiler heat recovery, including a gas boiler, a two-stage energy storage device, an outdoor defrost coil, an electric control valve, and an antifreeze water pump. , antifreeze water pipe, reverse cycle defrost pipe, heat user, indoor heat exchanger, compressor, gas-liquid separator, outdoor heat exchanger, M1 electric three-way valve, M2 electric three-way valve;

In the heat storage stage, the gas boiler is connected to the two-stage energy storage device through the boiler exhaust pipe. A flue gas exhaust port is provided at the left end of the boiler exhaust pipe. The flue gas generated by the combustion of the gas boiler passes through the boiler exhaust pipe and is discharged from the two-stage energy storage device. The flue gas inlet of the device enters the dual-stage energy storage device, and then is discharged through the flue gas outlet of the dual-stage energy storage device. A partition is provided in the dual-stage energy storage device to separate the interior of the dual-stage energy storage device into a left energy storage chamber. chamber and the right energy storage chamber. The left energy storage chamber is equipped with a secondary phase change energy storage material, and the right energy storage chamber is equipped with a primary phase change energy storage material. Among them, the primary phase change energy storage material is made by adding trihydroxy Pentaerythritol of methylpropane. The phase change temperature of pentaerythritol is 115-125°C. It is used to absorb sensible heat in the flue gas discharged from gas boilers. The secondary phase change energy storage material uses 2,2-dimethylol-propanol. The phase change temperature of 2,2-dimethylol-propanol is 95-105°C, which is used to absorb the latent heat of vaporization in the flue gas discharged from gas boilers;

In the external defrost cycle, the antifreeze water pipe is connected to the outdoor defrost coil. The antifreeze water pipe enters from the antifreeze water inlet set at the bottom of the left energy storage chamber. It first passes through the secondary phase change energy storage material, and then passes through the primary phase change energy storage material. , coming out from the antifreeze water outlet set at the bottom of the right energy storage chamber, the antifreeze water pipe is equipped with an electric control valve, an antifreeze water pump, and an antifreeze water channel valve in sequence;

For reverse cycle defrosting, the compressor is connected to the four-way reversing valve. The four-way reversing valve is divided into two circuits: one is the compressor, gas-liquid separator, four-way reversing valve, outdoor heat exchanger, expansion valve and M2 electric The three-way valve is connected in sequence, and the other route compressor, four-way reversing valve and M1 electric three-way valve are connected in sequence. One end of the reverse cycle defrost pipe is set at the refrigerant inlet at the top of the right energy storage chamber, and the other end is set at The refrigerant outlet at the top of the left storage chamber, one end of the reverse cycle defrost pipe is connected to port a of the M2 electric three-way valve through the manual valve, and the other end is connected to port a of the M1 electric three-way valve to form a circulation loop, M1 Port b of the electric three-way valve is connected to port b of the M2 electric three-way valve through the indoor heat exchanger. Port c of the M2 electric three-way valve passes through the expansion valve, outdoor heat exchanger, four-way reversing valve, and gas-liquid separation in sequence. The device, compressor and port c of the M1 electric three-way valve are connected to form a circulation loop;

One end of the indoor heat exchanger is connected to the heat user through a hot water exchange pump, and the other end is connected to the heat user through a pipeline check valve.

Further, electric heating devices are respectively installed at the bottoms of the left energy storage chamber and the right energy storage chamber.

Further, temperature sensors are installed on the tops of both the energy storage chamber and the right energy storage chamber.

Further, the exterior of the two-stage energy storage device is provided with a thermal insulation outer casing.

Further, antifreeze liquid is stored in the antifreeze water pipe.

Further, an anti-corrosion insulation layer is provided on the outside of the anti-freeze water pipe.

Further, a frost detector is installed on the outdoor heat exchanger.

Further, the antifreeze water pipe and the reverse cycle defrost pipe are arranged side by side in a spiral shape in the two-stage energy storage device.

Compared with the existing technology, the present invention has the following beneficial effects:

1. The energy storage defrost device of the present invention can make full use of the waste gas after combustion of the gas boiler and store the heat through the two-stage energy storage device to make full use of the heat; while also meeting the environmental and economical requirements.

2. During the defrosting process of the energy storage defrosting device of the present invention, there is no need for the air source heat pump unit to absorb the heat in the user's room through reversal to defrost, but to defrost through the heat source of the dual-stage energy storage device to ensure The indoor temperature will not fluctuate, while the loss of the valve can be reduced and the service life of the compressor can be extended.

Description of the drawings

Figure 1 is a schematic structural diagram of the energy storage defrosting device of the present invention;

Figure 2 is a schematic structural diagram of the antifreeze water pipe and reverse cycle defrost pipe of the present invention;

Figure 3 is a schematic structural diagram of a temperature detection sensor and a connector connected to the temperature sensor according to the present invention.

Among them, 1-gas boiler; 2-boiler exhaust pipe; 3-double-stage energy storage device; 301-flue gas inlet; 302-flue gas outlet; 303-partition; 304-left energy storage chamber; 305-right Energy storage chamber; 306-antifreeze water inlet; 307-antifreeze water outlet; 308-refrigerant inlet; 309-refrigerant outlet; 310-boiler exhaust pipe; 311-temperature sensor; 312-electric heating device; 313-two Level phase change energy storage material; 314-First level phase change energy storage material; 4-smoke exhaust port; 5-antifreeze water pipe; 6-outdoor defrost coil; 7-electric control valve; 8-antifreeze water pump; 9-Antifreeze water waterway valve; 10-Outdoor heat exchanger; 11-Frost layer detector; 12-Four-way reversing valve; 13-Compressor; 14-Gas-liquid separator; 15-Expansion valve; 16-M1 electric Three-way valve; 17- M2 electric three-way valve; 18- manual valve; 19- reverse cycle defrost pipe; 20- indoor heat exchanger; 21- pipeline check valve; 22- hot water exchange pump; 23- heat user .

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings to make the purpose, advantages and technical solutions of the present invention clearer.

It should be noted that this drawing is only used as a technical illustration to facilitate the description of the present invention and simplify the description. It does not specifically indicate the installation position of the system or that the indicating device and original components must have a specific orientation, as well as a specific orientation construction and operation and therefore should not be construed as limitations of the invention.

Referring to Figure 1, the present invention provides an energy storage defrosting device for gas boiler heat recovery, including a gas boiler 1, a two-stage energy storage device 3, an outdoor defrost coil 6, an electric control valve 7, an antifreeze water pump 8, and an antifreeze water pump. Water pipe 5, reverse cycle defrost pipe 19, heat user 23, indoor heat exchanger 20, compressor 13, gas-liquid separator 14, outdoor heat exchanger 10, M1 electric three-way valve 16, M2 electric three-way valve 17;

In the heat storage stage, the gas boiler 1 is connected to the double-stage energy storage device 3 through the boiler exhaust pipe 2. The left end of the boiler exhaust pipe 2 is provided with a flue gas exhaust port 4. The flue gas generated by the combustion of the gas boiler 1 is exhausted through the boiler. The pipeline 2 enters the dual-stage energy storage device 3 from the flue gas inlet 301 of the dual-stage energy storage device 3, and then is discharged through the flue gas outlet 302 of the dual-stage energy storage device 3. The dual-stage energy storage device 3 is provided with a partition 303 , the dual-stage energy storage device 3 is internally separated into a left energy storage chamber 304 and a right energy storage chamber 305. The left energy storage chamber 304 is provided with a secondary phase change energy storage material 313, and the right energy storage chamber 305 is provided with a secondary phase change energy storage material 313. A first-level phase change energy storage material 314 is provided, wherein the first-level phase change energy storage material 314 uses pentaerythritol added with trimethylolpropane. The phase change temperature of pentaerythritol is 115-125°C and is used to absorb the flue gas discharged from the gas boiler 1. The sensible heat in the secondary phase change energy storage material 313 uses 2,2-dimethylol-propanol. The phase change temperature of 2,2-dimethylol-propanol is 95-105°C for absorption. The gas boiler 1 discharges the latent heat of vaporization in the flue gas.

The exterior of the two-stage energy storage device 3 is provided with a thermal insulation outer casing.

Referring to Figures 1 and 2, in the external defrost cycle, the antifreeze water pipe 5 is connected to the outdoor defrost coil 6. The antifreeze water pipe 5 enters from the antifreeze water inlet 306 provided at the bottom of the left energy storage chamber 304, and first passes through the secondary phase change storage Energy material 313, and then through the first-level phase change energy storage material 314, comes out from the antifreeze water outlet 307 provided at the bottom of the right energy storage chamber 305. The antifreeze water pipe 5 is provided with an electric control valve 7, an antifreeze water pump 8, and antifreeze water in sequence. Waterway valve 9.

For reverse cycle defrosting, the compressor 13 is connected to the four-way reversing valve 12. The four-way reversing valve 12 is divided into two routes: one route is the compressor 13, the gas-liquid separator 14, the four-way reversing valve 12, and the outdoor heat exchanger. 10. The expansion valve 15 is connected to the M2 electric three-way valve 17 in sequence, and the other route compressor 13, the four-way reversing valve 12 and the M1 electric three-way valve 16 are connected in sequence. One end of the reverse cycle defrost pipe 19 is set on the right accumulator. The refrigerant inlet 308 at the top of the energy chamber 305, the other end is provided at the refrigerant outlet 309 at the top of the left energy storage chamber 304, one end of the reverse cycle defrost pipe 19 passes through the manual valve 18 and the a port of the M2 electric three-way valve 17 The other end is connected to port a of M1 electric three-way valve 16 to form a circulation loop. Port b of M1 electric three-way valve 16 is connected to port b of M2 electric three-way valve 17 through indoor heat exchanger 20. M2 electric three-way valve 17 Port c of the valve 17 is connected to port c of the M1 electric three-way valve 16 through the expansion valve 15, outdoor heat exchanger 10, four-way reversing valve 12, gas-liquid separator 14, compressor 13 and M1 electric three-way valve 16 in sequence, forming a circulation loop.

Antifreeze liquid is stored in the antifreeze water pipe 5 .

The exterior of the antifreeze water pipe 5 is provided with an anticorrosive insulation layer.

A frost layer detector 11 is installed on the outdoor heat exchanger 10 .

Referring to Figure 2, the antifreeze water pipe 5 and the reverse cycle defrost pipe 19 are spirally arranged side by side in the two-stage energy storage device 3.

The defrost mode is divided into two situations: the surface of the outdoor heat exchanger 10 is monitored through the frost layer detector 11 installed on the outdoor heat exchanger 10. When the frost layer thickness on the surface reaches the first limit value, the electric control valve 7 is turned on, the antifreeze water pump 8 is started, and the antifreeze in the antifreeze water pipe 5 is driven by the antifreeze water pump 8 and enters the double-stage energy storage device 3 for heat exchange. After the temperature rises to 55°C~60°C, it enters the outdoor defrost tray. In the pipe 6, the surface of the outdoor heat exchanger 10 is heated and defrosted under the action of convection heat transfer. At this time, port a of the M1 electric three-way valve 16 is closed and port b and port c are opened, and the M2 electric three-way valve 17 is opened. Port a closes port b and port c opens, and the system works normally; when the frost layer thickness on the surface reaches the second limit value, the antifreeze water pump 8 stops, the pipe valve of the antifreeze water pipe 5 closes, and the outdoor defrost device stops working, M1 Port b of the electric three-way valve 16 closes port a and opens port c. Port b of the M2 electric three-way valve 17 closes port a and opens port c. The four-way reversing valve 12 reverses direction. At this time, the air source heat pump reverses the direction. Cycle defrost; the refrigerant in the heat pump enters the double-stage energy storage device 3 through the M2 electric three-way valve 17 to heat up, and then enters the outdoor heat exchanger 10 to condense and release heat, defrosting the surface. After the defrost is completed, the M1 electric Port a of the three-way valve 16 and the M2 electric three-way valve 17 closes port b and opens port c, and the four-way reversing valve 12 switches to the air source heat pump to start normal heating work.

Continuing to refer to FIG. 1 , one end of the indoor heat exchanger 20 is connected to the heat user 23 through the hot water exchange pump 22 , and the other end is connected to the heat user 23 through the pipeline check valve 21 .

Referring to Figure 3, a temperature sensor 311 is installed on the top of the left energy storage chamber 304 and the right energy storage chamber 305, and an electric heating device 312 is installed on the bottom.

The heat storage process of the double-stage energy storage device 3 can be divided into two situations: the flue gas generated by the combustion of the gas boiler 1 is discharged from the boiler exhaust pipe 2, and the 150°C high-temperature flue gas passes through the double-stage energy storage device 3 for heat exchange and transfers the heat Storage, taking full advantage of the relatively low price of off-peak electricity at night, the electric heating device 312 installed in the dual-stage energy storage device 3 pre-storages the dual-stage energy storage device 3 through the left energy storage chamber. 304 and the temperature sensor 311 on the top of the right energy storage chamber 305 monitors the heat storage when the heat storage reaches 60% of the maximum heat storage; during the defrosting process, if the heat storage of the double-stage energy storage device 3 is less than 20% , the electric heating device 312 is turned on to perform heating and defrosting.

The limited temperatures mentioned above depend on the temperature and humidity of the local environment. At the same time, due to different electricity and natural gas costs in different places, the critical temperature is also different. Through the numerical feedback of outdoor temperature and humidity, the local critical temperature can be pre-calculated and the defrosting efficiency can be improved by selecting a reasonable limit temperature.

The opening and closing of all the above valves and water pumps are controlled by an automated control system based on PLC programming. Through the monitoring of frost layer detectors, the most appropriate start and stop times are selected to reduce the frequency and duration of defrost.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, but not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention. The scope shall be covered by the scope of the claims and description.

The above embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above-mentioned embodiment, and many modifications are possible. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention belong to the protection scope of the present invention.

Claims (8)

1. The energy storage defrosting device for heat recovery of the gas boiler is characterized by comprising the gas boiler, a two-stage energy storage device, an outdoor defrosting coil pipe, an electric control valve, an antifreezing water pump, an antifreezing water pipe, a reverse circulation defrosting pipe, a heat user, an indoor heat exchanger, a compressor, a gas-liquid separator, an outdoor heat exchanger, an M1 electric three-way valve and an M2 electric three-way valve;

in the heat storage stage, a gas boiler is connected with a two-stage energy storage device through a boiler exhaust pipeline, a smoke exhaust port is arranged at the left end of the boiler exhaust pipeline, smoke generated by combustion of the gas boiler enters the two-stage energy storage device from a smoke inlet of the two-stage energy storage device through the boiler exhaust pipeline and is discharged through a smoke outlet of the two-stage energy storage device, a partition plate is arranged in the two-stage energy storage device to separate the interior of the two-stage energy storage device into a left energy storage cavity and a right energy storage cavity, a second-stage phase change energy storage material is arranged in the left energy storage cavity, and a first-stage phase change energy storage material is arranged in the right energy storage cavity, wherein the first-stage phase change energy storage material adopts pentaerythritol added with trimethylolpropane, the phase change temperature of pentaerythritol is 115-125 ℃ and is used for absorbing sensible heat in smoke discharged by the gas boiler, the second-stage phase change energy storage material adopts 2, 2-dimethylol-propanol, and the phase change temperature of 2, 2-dimethylol-propanol is 95-105 ℃ and is used for absorbing gasification latent heat in the smoke discharged by the gas boiler;

the external defrosting cycle is that an anti-freezing water pipe is connected with an outdoor defrosting coil pipe, the anti-freezing water pipe enters from an anti-freezing water inlet arranged at the bottom of a left energy storage cavity, passes through a second-level phase change energy storage material and then passes through a first-level phase change energy storage material, and exits from an anti-freezing water outlet arranged at the bottom of a right energy storage cavity, and an electric control valve, an anti-freezing water pump and an anti-freezing water waterway valve are sequentially arranged on the anti-freezing water pipe;

reverse circulation defrosting, the compressor is connected with a four-way reversing valve, and the four-way reversing valve is divided into two paths: one route is connected with an M2 electric three-way valve in sequence by a compressor, a gas-liquid separator, a four-way reversing valve, an outdoor heat exchanger and an expansion valve, the other route is connected with an M1 electric three-way valve in sequence by a compressor, the four-way reversing valve and the reverse circulation defrosting pipe, one end of the reverse circulation defrosting pipe is arranged at a refrigerant inlet at the top of a right energy storage cavity, the other end of the reverse circulation defrosting pipe is arranged at a refrigerant outlet at the top of a left energy storage cavity, one end of the reverse circulation defrosting pipe is connected with an a port of the M2 electric three-way valve through a manual valve, the other end of the reverse circulation defrosting pipe is connected with an a port of the M1 electric three-way valve to form a circulation loop, a port b of the M1 electric three-way valve is connected with a port b of the M2 electric three-way valve through an indoor heat exchanger, and a port c of the M2 electric three-way valve is connected with a port c of the expansion valve, the outdoor heat exchanger, the four-way reversing valve, the gas-liquid separator and the compressor are connected with a port c of the M1 electric three-way valve in sequence to form a circulation loop;

one end of the indoor heat exchanger is connected with the heat user through a heat exchange water pump, and the other end of the indoor heat exchanger is connected with the heat user through a pipeline check valve.

2. The energy storage defrosting device for heat recovery of a gas boiler according to claim 1, wherein the bottoms of the left energy storage chamber and the right energy storage chamber are respectively provided with an electric heating device.

3. The energy storage defrosting device for heat recovery of a gas boiler according to claim 1, wherein the top of each of the energy storage chamber and the right energy storage chamber is provided with a temperature sensor.

4. The energy storage and defrosting device for heat recovery of a gas boiler according to claim 1, wherein a heat preservation outer shell is arranged outside the two-stage energy storage device.

5. The energy storage defroster of heat recovery of a gas boiler according to claim 1, wherein an antifreeze solution is stored in the antifreeze water pipe.

6. The energy storage defrosting device for heat recovery of a gas boiler according to claim 1, wherein an anti-corrosion heat preservation layer is arranged outside the anti-freezing water pipe.

7. The energy storage defroster of heat recovery of a gas boiler according to claim 1, wherein a frost layer detector is installed on the outdoor heat exchanger.

8. The energy storage defrosting device for heat recovery of a gas boiler according to claim 1, wherein the antifreeze water pipe and the reverse circulation defrosting pipe are spirally arranged side by side in the two-stage energy storage device.