CN219083146U

CN219083146U - System for producing hot water by utilizing solar energy and boiler flue gas waste heat in combined operation

Info

Publication number: CN219083146U
Application number: CN202222295190.7U
Authority: CN
Inventors: 赵化涛; 石灿; 李建; 薛垚
Original assignee: Beijing Changfeng Xinlian Engineering Management Co ltd
Current assignee: Beijing Changfeng Xinlian Engineering Management Co ltd
Priority date: 2022-08-30
Filing date: 2022-08-30
Publication date: 2023-05-26
Anticipated expiration: 2032-08-30

Abstract

A system for producing hot water by utilizing solar energy and boiler flue gas waste heat in a combined operation mode relates to the technical field of heat supply. Comprises a boiler, a first-stage condenser, a second-stage condenser, a solar heat collector, a water tank, a water pump, an air preheater and a control device. The first-stage condenser and the second-stage condenser are sequentially arranged on a boiler chimney in series, the water outlet pipe of the second-stage condenser is divided into two paths, one path of the water enters the solar heat collector through the electric valve I and then is communicated with the water tank inlet, and the other path of the water enters the water tank inlet through the electric valve II. The solar water heater can fully recycle the waste heat of the flue gas to heat the heat medium water, and simultaneously, the solar water heater supplements and heats the heat water produced by the combined operation of the solar water heater and the waste heat of the flue gas to the water tank. The heat medium water has two uses, on the one hand for preheating the air entering the boiler burner and on the other hand for domestic water. The waste heat and solar energy discharged by the boiler are fully utilized as heat sources, so that the energy is saved, the cost is reduced, and the environmental pollution is also reduced.

Description

System for producing hot water by utilizing solar energy and boiler flue gas waste heat in combined operation

Technical Field

The utility model relates to the technical field of heat supply, in particular to a system for producing hot water by utilizing deep recovery of waste heat of boiler flue gas and solar energy combined operation.

Background

The gas boiler is used as main heating equipment, and the flue gas generated by combustion contains a large amount of waste heat and is directly discharged into the atmosphere, so that energy waste is caused. Although the existing boilers are provided with flue gas waste heat recovery condensers, the heat exchange is carried out on the boiler backwater and the flue gas, the temperature of the backwater is limited, the temperature of the backwater can only be reduced to about 60 ℃, the waste heat cannot be effectively recovered, and a heat source cannot be provided for users in non-heating seasons. Meanwhile, solar energy is inexhaustible, clean and pollution-free renewable energy, and cannot provide continuous and stable energy supply for a system under the influence of factors such as day and night, climate, seasons and the like, but is widely applied due to great development potential. Therefore, the deep recycling technology of the flue gas waste heat is further explored, and the flue gas waste heat and the solar technology are combined, so that the waste heat can be further recycled deeply, two low-grade energy sources of industrial waste heat and solar energy can be fully utilized, the requirements of users are better met, and the deep recycling technology of the flue gas waste heat is an important energy-saving and emission-reducing technology and has a wide application prospect.

Disclosure of Invention

In order to solve the problems in the background art, the utility model aims to design a system for producing hot water by utilizing solar energy and a boiler flue gas waste heat recovery technology in a combined operation mode, and the system fully utilizes low-grade energy sources for preparing domestic hot water and heating air, improves energy utilization efficiency and promotes economic operation of a boiler.

In order to achieve the above purpose, the present utility model provides the following technical solutions: the system for producing hot water by utilizing the combined operation of solar energy and the waste heat of boiler flue gas is characterized by mainly comprising a boiler (1), a primary condenser (2), a secondary condenser (3), a solar heat collector (4), a water tank (5), a circulating water pump (6), an air preheater (7), an electric water heater (8) and a control device (9); the smoke outlet (10) of the boiler is provided with an upward chimney (11) for exhausting smoke generated by combustion of the boiler to the outdoor atmosphere, the outer side of the lower part of the chimney (11) is provided with a first-stage condenser (2), the outer side of the upper part of the chimney is provided with a second-stage condenser (3), namely, the first-stage condenser is arranged at one end of the chimney, which is close to the smoke outlet of the boiler, and the second-stage condenser is arranged at one end of the chimney, which is higher than a roof; the first-stage condenser water inlet pipe (12) and the first-stage condenser water outlet pipe (14) are connected with a boiler water return pipe (13), and an access point of the first-stage condenser water outlet pipe (14) and the boiler water return pipe (13) on the boiler water return pipe (13) is positioned at the downstream of an access point of the first-stage condenser water inlet pipe (12) and the boiler water return pipe; the water outlet pipe (15) of the secondary condenser is divided into two paths, wherein one path is connected with the water inlet of the solar heat collector (4) arranged on the roof through an electric valve I (16), the water outlet pipe of the solar heat collector (4) is communicated with the water inlet pipe (17) of the water tank, and the other path is directly communicated with the water outlet pipe (19) of the solar heat collector through an electric valve II (18); the water tank water outlet pipe (20) is communicated with the water inlet of the circulating water pump (6), the outlet of the circulating water pump is divided into two paths, one path is communicated with the water inlet pipe (22) of the air preheater through the gate valve I (21), the water outlet pipe of the air preheater (7) is connected with the water inlet of the secondary condenser through the secondary condenser water return pipe (23), and the other path is directly communicated with the water inlet pipe of the solar heat collector (4) through the gate valve II (24).

Further, the water tank (5) is a heat storage water device, which stores the heat of hot water produced by the solar heat collector and the flue gas waste heat recovery, and directly transmits the heat to a user under the condition of meeting the required temperature.

Further, a heat exchange tube (25) is coiled in the water tank (5), a water inlet and a water outlet of the heat exchange tube (25) are positioned at the outer side of the water tank (5), the water inlet of the heat exchange tube (25) is communicated with a tap water pipe, and the water outlet of the heat exchange tube (25) is connected with a domestic hot water pipe through an electric water heater (8); the heat exchange tube (25) is internally provided with domestic circulating water which exchanges heat with hot water in the water tank and is heated to be supplied to a user. The heat exchange tubes (25) positioned in the water tank are arranged in a plurality of rows, so that the efficiency of heating water is higher, and the recycling of heat energy is realized.

Further, the air preheater (7) is installed on a top window of an outer wall of the boiler to preheat cold air entering outdoors. And the air inlet of the air preheater (7) is directly communicated with the atmosphere, the outlet is arranged in a boiler room, cold air enters the burner of the boiler after being preheated by the air preheater (7), and the air is preheated in advance before being combusted, so that the aim of saving energy is fulfilled.

Further, a temperature sensor (26) is arranged on the water outlet pipe of the secondary condenser, and the circulating water pump (6), the electric valve I (16), the electric valve II (18) and the temperature sensor (26) are electrically connected with the control device (9). The temperature sensor (26) is used for monitoring the temperature of the outlet water of the secondary condenser and transmitting the temperature data to the control device (9) so as to control the opening and closing of the valve, namely the opening and closing of the corresponding electric valve.

The utility model has the following beneficial effects:

the system for producing hot water and preheating air by utilizing the deep recovery of the waste heat of the boiler flue gas and the combined operation of solar energy fully utilizes the waste heat and the solar energy discharged by the boiler combustion as heat sources, thereby greatly saving energy, reducing production cost and simultaneously reducing environmental pollution.

(1) The utility model combines the boiler waste heat and the solar energy technology, can fully utilize the low-temperature waste heat and the solar energy, supplements each other, saves energy, improves the energy utilization rate of the system, reduces the emission of pollutants such as carbon dioxide and the like because the energy is derived from the waste heat and the solar energy, relieves the energy pressure, and has good social benefit and economic benefit.

(2) The utility model can effectively recover the waste heat of the boiler flue gas, the flue gas firstly exchanges heat in the primary condenser to cool, heats the return water of the boiler, then enters the secondary condenser to serve as a low-level heat source to further exchange heat to cool, heats the coolant water, fully recovers the waste heat in the flue gas, and embodies the heat cascade utilization of waste heat media. The flue gas is discharged to the atmosphere after being utilized by the first-stage condenser and the second-stage condenser, so that the utilization rate of energy sources can be improved, and the production cost is reduced. And a part of the recovered heat is used for domestic hot water, and the other part of the recovered heat heats the backwater of the boiler and preheats the air to return to the boiler for on-site utilization, so that the fuel can be further saved, the primary energy consumption is reduced, and the heat supply efficiency of the boiler is effectively improved.

Drawings

FIG. 1 is a schematic diagram of the present utility model.

In the figure: 1. a boiler; 2. a first-stage condenser; 3. a second-stage condenser; 4. a solar collector; 5. a water tank; 6. a circulating water pump; 7. an air preheater; 8. electric water heater; 9. a control device; 10. a smoke outlet; 11. a chimney; 12. a primary condenser inlet pipe; 13. a boiler return pipe; 14. a condenser outlet pipe; 15. a second-stage condenser outlet pipe; 16. an electric valve I;17. a water tank inlet pipe; 18. an electric valve II;19. a water outlet pipe of the solar heat collector; 20. a water outlet pipe of the water tank; 21. a gate valve I;22. an air preheater inlet pipe; 23. a secondary condenser return pipe; 24. a gate valve II;25. a heat exchange tube; 26. a temperature sensor.

Detailed Description

The present utility model will be described in detail with reference to the drawings and the detailed description, but the present application is not limited to the following examples.

Example 1

As shown in fig. 1, a system for producing hot water by utilizing solar energy and boiler flue gas waste heat in a combined operation mode mainly comprises a boiler (1), a primary condenser (2), a secondary condenser (3), a solar heat collector (4), a water tank (5), a circulating water pump (6), an air preheater (7), an electric water heater (8) and a control device (9). The flue gas outlet (10) of the boiler is communicated with a chimney (11) for exhausting flue gas generated by combustion of the boiler to outdoor atmosphere, the primary condenser (2) and the secondary condenser (3) are sequentially arranged on the chimney (11) in series, the primary condenser is at one end of the chimney close to the flue gas outlet of the boiler, and the secondary condenser is at one end of the chimney higher than a roof. The primary condenser water inlet pipe (12) is connected with the boiler water return pipe (13), and the primary condenser water outlet pipe (14) and the boiler water return pipe are connected in parallel and then enter the boiler. The water outlet pipe (15) of the secondary condenser is divided into two paths, one path enters the solar heat collector arranged on the roof through the electric valve I (16) and is communicated with the water inlet pipe (17) of the water tank, and the other path is directly communicated with the water outlet pipe (19) of the solar heat collector through the electric valve II (18) and is communicated with the water inlet pipe (17) of the water tank after being connected with the water inlet pipe (19) of the solar heat collector through a pipeline. The outlet pipe (20) of the water tank is communicated with the circulating water pump (6), the outlet of the circulating water pump is divided into two paths, one path is communicated with the air preheater water inlet pipe (22) through the gate valve I (21), then the water returns to the secondary condenser through the secondary condenser water return pipe (23), and the second path is directly communicated with the solar heat collector water inlet pipe behind the electric valve I (16) through the gate valve II (24) in such a circulating way.

Further, the water tank is a heat storage device, which stores the heat of hot water produced by the solar heat collector and the flue gas waste heat recovery, and directly transmits the heat to a user under the condition of meeting the required temperature.

Further, a heat exchange tube (25) is arranged in the water tank, the heat exchange tube (25) penetrates through and extends to the outer side of the water tank, one water inlet of one end of the heat exchange tube (25) positioned at the outer side of the water tank is communicated with tap water, and the water outlet of the other end of the heat exchange tube is communicated with a tap. The heat exchange tube (25) internally flows with domestic circulating water, and the domestic circulating water exchanges heat with water in the water tank and is supplied to a user after being heated. The heat exchange tubes (25) positioned in the water tank are arranged in a plurality of rows, so that the efficiency of heating water is higher, and the recycling of heat energy is realized.

Further, a temperature sensor (26) is also respectively installed on the water outlet pipe of the secondary condenser, and the circulating water pump, the electric valve I (16), the electric valve II (18) and the temperature sensor (26) are all connected to the control device. The temperature sensor (26) is used for monitoring the temperature of the outlet water of the condenser and transmitting the temperature data to a control device for controlling the opening and closing of the valve so as to control the opening and closing of the corresponding electric valve.

A system for producing hot water by utilizing deep recovery of waste heat of boiler flue gas and solar energy combined operation comprises two operation modes: the independent operation and the double heat source combined operation can be realized, and the utilization of the heat source can be adjusted by switching the opening and closing combination of the valve. The utility model can adjust whether to utilize the waste heat of the flue gas by switching the opening and closing combination of the gate valve I and the gate valve II. When the heating season boiler operates, the exhaust gas temperature of the boiler is higher, the exhaust gas waste heat of the flue gas can be utilized, the gate valve I is opened, the gate valve II is closed, at the moment, high-temperature flue gas exhausted by the boiler exchanges heat with boiler backwater in the primary condenser, the boiler backwater exchanges heat with the high-temperature flue gas in a convection mode, the exhaust gas waste heat is absorbed, the temperature is increased, the backwater is preheated in advance, the output of the boiler can be reduced under the condition of constant rated water supply temperature, and the fuel gas consumption is reduced; and (3) allowing low-temperature flue gas after heat exchange between the primary condenser and boiler backwater to enter the secondary condenser for secondary heat exchange with circulating water, and performing deep waste heat recovery to prepare condenser effluent with higher temperature. Whether the condenser water outlet needs further supplementary heating of the solar heat collector can be adjusted whether to utilize the solar heat collector by switching the opening and closing combination of the electric valve I and the electric valve II. The control device controls the opening and closing of the electric valve I and the electric valve II according to the outlet water temperature of the condenser measured by the temperature sensor. When the sensor monitors that the outlet water temperature of the condenser is higher than a certain set value, the requirements of users are met, solar energy is not needed to be supplemented, only the waste heat of the boiler flue gas is recovered deeply and only the boiler flue gas is required to operate independently, the electric valve I is closed, the solar heat collector is closed, the electric valve II of the bypass pipeline of the solar heat collector is opened, and the heat medium water directly enters the water tank after flowing out of the condenser and does not need to pass through the solar heat collector. When the temperature is lower than a certain set value, the solar heat collector is required to be used for supplementing heating, the double heat sources are operated in a combined mode, the electric valve I is opened, the electric valve II is closed, at the moment, the secondary condenser and the solar heat collector are in a series connection mode, and condenser effluent enters the solar heat collector through the electric valve I and then enters the water tank after being heated again. The heat medium water prepared by the flue gas waste heat recovery of the secondary condenser and the solar energy has two purposes. On the one hand, the air preheating device is used for preheating air entering the boiler burner, and air required by boiler combustion is heated by convection heat exchange of the air preheater and hot water and then is sent into the boiler for combustion, so that the fuel consumption of the system can be reduced. On the other hand, the tap water flowing in the heat exchange tube is used for domestic water to exchange heat with the hot water in the water tank by convection, and the tap water absorbs heat and is supplied to users. In addition, when the outdoor temperature is higher and the solar radiation amount is stronger, the water consumption requirement can be met by singly using solar energy; when the outdoor air temperature is extremely low and the solar radiation is insufficient, the domestic water supply pipe of the system is also provided with an electric water heater, solar energy and smoke waste heat can not provide required heat for users in summer when the boiler does not operate and under the condition of no solar radiation, and domestic hot water is directly prepared for the users by using the water heater.

When the non-heating season boiler is not in operation, the waste heat of the flue gas cannot be utilized, the air entering the boiler burner is not required to be preheated, only the domestic water is required to be prepared, and the solar energy is independently operated. At the moment, the gate valve II is opened, the gate valve I is closed, the solar heat collector is started, the refrigerant water does not need to flow through the secondary condenser for heating, directly enters the solar heat collector for heating, then enters the water tank, and then returns to the solar heat collector for circulation after being pressurized by the water pump.

Claims

1. The system for producing hot water by utilizing the combined operation of solar energy and the waste heat of boiler flue gas is characterized by mainly comprising a boiler (1), a primary condenser (2), a secondary condenser (3), a solar heat collector (4), a water tank (5), a circulating water pump (6), an air preheater (7), an electric water heater (8) and a control device (9); the smoke outlet (10) of the boiler is provided with an upward chimney (11) for exhausting smoke generated by combustion of the boiler to the outdoor atmosphere, the outer side of the lower part of the chimney (11) is provided with a first-stage condenser (2), the outer side of the upper part of the chimney is provided with a second-stage condenser (3), namely, the first-stage condenser is arranged at one end of the chimney, which is close to the smoke outlet of the boiler, and the second-stage condenser is arranged at one end of the chimney, which is higher than a roof; the first-stage condenser water inlet pipe (12) and the first-stage condenser water outlet pipe (14) are connected with a boiler water return pipe (13), and an access point of the first-stage condenser water outlet pipe (14) and the boiler water return pipe (13) on the boiler water return pipe (13) is positioned at the downstream of an access point of the first-stage condenser water inlet pipe (12) and the boiler water return pipe; the water outlet pipe (15) of the secondary condenser is divided into two paths, wherein one path is connected with the water inlet of the solar heat collector (4) arranged on the roof through an electric valve I (16), the water outlet pipe of the solar heat collector (4) is communicated with the water inlet pipe (17) of the water tank, and the other path is directly communicated with the water outlet pipe (19) of the solar heat collector through an electric valve II (18); the water outlet pipe (20) of the water tank is communicated with the water inlet of the circulating water pump (6), the outlet of the circulating water pump is divided into two paths, one path is communicated with the water inlet pipe (22) of the air preheater through the gate valve I (21), the water outlet pipe of the air preheater (7) is connected with the water inlet of the secondary condenser through the water return pipe (23) of the secondary condenser, and the other path is directly communicated with the water inlet pipe of the solar heat collector (4) through the gate valve II (24);

the water tank (5) is internally provided with a heat exchange tube (25), a water inlet and a water outlet of the heat exchange tube (25) are positioned at the outer side of the water tank (5), the water inlet of the heat exchange tube (25) is communicated with a tap water pipe, and the water outlet of the heat exchange tube (25) is connected with a domestic hot water pipe through an electric water heater (8);

the water outlet pipe of the secondary condenser is provided with a temperature sensor (26), and the circulating water pump (6), the electric valve I (16), the electric valve II (18) and the temperature sensor (26) are electrically connected with the control device (9).

2. A system for producing hot water by combined operation of solar energy and waste heat of boiler flue gas according to claim 1, wherein the heat exchange tubes (25) located inside the water tank are arranged in a plurality of rows.

3. A system for producing hot water by utilizing solar energy and waste heat of boiler flue gas in combination operation according to claim 1, wherein the air preheater (7) is arranged on a top window of an outer wall of the boiler; and the air inlet of the air preheater (7) is directly communicated with the atmosphere, the outlet is arranged in a boiler room, and cold air enters the burner of the boiler after being preheated by the air preheater (7).

4. A system for producing hot water by combined operation of solar energy and waste heat of boiler flue gas according to claim 1, wherein the temperature sensor (26) is used for monitoring the temperature of the outlet water of the secondary condenser and transmitting the temperature data to the control device (9) to control the opening and closing of the valve, namely, the opening and closing of the corresponding electric valve.