Steam boiler tail gas waste heat water circulation heating system

Abstract

The utility model discloses a steam boiler tail gas waste heat water circulation heating system which comprises a main water tank, a steam boiler, a waste heat heating device and a preheating water tank. The water inlet end of the preheating water tank is connected with the main water tank, the water outlet end of the preheating water tank is connected with the waste heat heating device through the circulating water pump, the waste heat heating device is arranged on the top of the steam boiler, one water outlet end of the waste heat heating device supplies water to the steam boiler, and the other water outlet end of the waste heat heating device is connected with the preheating water tank. The water supply amount of the circulating water pump is larger than that of the waste heat heating device to the steam boiler. The steam boiler flue gas waste heat utilization device can achieve full utilization of steam boiler flue gas waste heat, guarantee the water supply temperature of the steam boiler and save energy.

Description

Technical Field

[0001] The utility model relates to a steam boiler tail gas waste heat water circulation heating system for the field of steam boilers. Background Art

[0002] A steam boiler is a device that converts thermal energy into steam or hot water to provide thermal energy or power. Heating the raw water by a steam boiler usually consumes a large amount of energy.

[0003] During the heating process, the steam boiler will generate flue gas with waste heat. In order to save energy, it is a commonly adopted technical means to set up a waste heat heating device that utilizes the waste heat of the flue gas to preheat the raw water of the steam boiler. The existing waste heat heating devices adopt the form of directly introducing the raw water, which enters the steam boiler body after preheating, and cannot make full use of the waste heat, resulting in waste of the waste heat and poor preheating effect. Content of the Utility Model

[0004] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a steam boiler tail gas waste heat water circulation heating system, which can realize the full utilization of the waste heat of the steam boiler flue gas.

[0005] A technical solution to achieve the above purpose is: a steam boiler tail gas waste heat water circulation heating system, including a main water tank, a steam boiler and a waste heat heating device, and further including a preheating water tank.

[0006] The water inlet end of the preheating water tank is connected to the main water tank, the water outlet end of the preheating water tank is connected to the waste heat heating device through a circulating water pump, the waste heat heating device is arranged on the top of the steam boiler, one of its water outlet ends supplies water to the steam boiler, and its other water outlet end is connected to the preheating water tank. The circulating water pump is signal-connected to the control PLC of the steam boiler, and the water supply volume of the circulating water pump is greater than the water supply volume of the waste heat heating device to the steam boiler.

[0007] Furthermore, a water level monitoring and temperature monitoring device is provided on the preheating water tank.

[0008] Furthermore, a water inlet valve is provided at the water inlet end of the preheating water tank, and the water inlet valve is signal-connected to the water level monitoring and temperature monitoring device.

[0009] Furthermore, the outer side of the preheating water tank is coated with a heat insulation layer.

[0010] Furthermore, a check valve is provided on the water pipe of the waste heat heating device leading to the preheating water tank.

[0011] Furthermore, the preheating water tank is respectively connected to multiple groups of boilers.

[0012] Furthermore, two groups of circulating water pumps, one main and one standby, are respectively provided at the water outlet end of the preheating water tank.

[0013] A waste heat water circulation heating system for the tail gas of a steam boiler of the present utility model establishes a water circulation system between a waste heat heating device and a preheating water tank. The water supply from the preheating water tank to the steam boiler is greater than the water demand of the steam boiler, so that the water in the waste heat heating device can fully absorb heat and make the best use of waste heat as much as possible; the excess water returns to the preheating water tank through the water circulation system, raising the overall temperature of the preheating water tank and ensuring the water temperature of the raw water entering the steam boiler. The circulation water pump is signal-connected to the control PLC of the steam boiler and is turned off within a preset time after the steam boiler is turned off, so that the waste heat of the flue gas discharged subsequently can still be utilized after the steam boiler is turned off. The present utility model can make full use of the waste heat of the steam boiler, increase the temperature of the raw water entering the steam boiler, and save energy. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of a waste heat water circulation heating system for the tail gas of a steam boiler of the present utility model;

[0015] Figure 2 is a schematic structural diagram of a waste heat water circulation heating system for the tail gas of a steam boiler of the present utility model applied to multiple groups of steam boilers. Detailed Embodiment

[0016] In order to better understand the technical solution of the present utility model, the following is a detailed description through specific embodiments:

[0017] Please refer to Figure 1 , an embodiment of a waste heat water circulation heating system for the tail gas of a steam boiler of the present utility model, includes a main water tank 1, a preheating water tank 2, a steam boiler 3, and a waste heat heating device 4.

[0018] The water inlet end of the preheating water tank 2 is connected to the main water tank 1. The water outlet end of the preheating water tank 2 is connected to the waste heat heating device 4 through a circulation water pump 5. The waste heat heating device 4 is arranged on the top of the steam boiler 3 and uses the waste heat of the flue gas of the steam boiler to heat the raw water inside. One of its water outlet ends supplies water to the steam boiler 3, and the other water outlet end is connected to the preheating water tank 2. A check valve 6 is provided at the connection part. The circulation water pump 5 is signal-connected to the control PLC of the steam boiler 3, and the start and stop of the circulation water pump are controlled by the start and stop signals of the steam boiler 3 in a linked manner. The water supply volume of the circulation water pump is greater than the water supply volume of the waste heat heating device to the steam boiler.

[0019] When the steam boiler starts running, the circulating water pump starts synchronously. The softened water in the preheating water tank is supplied to the steam boiler through the waste heat heating device. The waste heat heating device simultaneously establishes a water cycle with the preheating water tank, fully absorbs and utilizes the waste heat of the steam boiler flue gas. The softened water that has been heated but not flowed into the steam boiler will flow back to the preheating water tank, and can raise the temperature of the softened water in the preheating water tank. When the steam boiler stops running, the circulating water pump will stop running 3 minutes after receiving the signal, ensuring that the water cycle between the waste heat heating device and the preheating water tank continues to operate, and making full use of the residual flue gas waste heat that will still be generated after the boiler stops.

[0020] Furthermore, the outer side of the preheating water tank is coated with a heat insulation layer. This heat insulation layer can ensure that the water in the preheating water tank can maintain a certain temperature after being preheated by the waste heat heating device, and will not lose temperature rapidly.

[0021] Furthermore, a water level monitoring and temperature monitoring device 7 is provided on the preheating water tank. An inlet valve 8 is provided at the water inlet end of the preheating water tank, and the inlet valve is signal-connected to the water level monitoring and temperature monitoring device. The main water tank will only replenish water to the preheating water tank after receiving the signals from the water level monitoring and temperature monitoring device, when the water level drops or the temperature is too high, to ensure that the water temperature in the preheating water tank will not be reduced.

[0022] After measurement, for the boiler system after the actual installation of the waste heat water circulation heating system of the steam boiler of the present utility model, the annual average temperature of the softened water of the steam boiler before the transformation was 20°C, and the annual average temperature of the softened water of the boiler after the transformation was 55°C. Through this transformation, a large amount of natural gas used by the steam boiler was saved.

[0023] Please refer to Figure 2 , another embodiment of a waste heat water circulation heating system for the steam boiler tail gas of the present utility model, which is applied to multiple groups of steam boilers. The preheating water tanks are respectively connected to multiple groups of boilers and share a return water pipeline. Two sets of circulating water pumps, one main and one standby, are respectively provided at the water outlet end of the preheating water tank to ensure the reliability of the water supply for each steam boiler.

[0024] Those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present utility model, rather than to limit the present utility model. As long as it is within the scope of the essential spirit of the present utility model, changes and modifications to the above embodiments will fall within the scope of the claims of the present utility model.

Claims

1. A waste heat water circulation heating system for the tail gas of a steam boiler, comprising a main water tank, a steam boiler and a waste heat heating device, characterized in that, It also includes a preheating water tank; The water inlet end of the preheating water tank is connected to the main water tank. The water outlet end of the preheating water tank is connected to the waste heat heating device through a circulating water pump. The waste heat heating device is arranged on the top of the steam boiler. One of its water outlet ends supplies water to the steam boiler, and the other water outlet end is connected to the preheating water tank. The circulating water pump is signal-connected to the control PLC of the steam boiler, and the water supply volume of the circulating water pump is greater than the water supply volume of the waste heat heating device to the steam boiler.

2. The steam boiler tail gas residual heat water circulation heating system according to claim 1, characterized in that, The preheating water tank is provided with a water level monitoring and temperature monitoring device.

3. A waste heat water circulation heating system for steam boiler tail gas according to claim 2, characterized in that, The water inlet end of the preheating water tank is provided with a water inlet valve, and the water inlet valve is signal-connected to the water level monitoring and temperature monitoring device.

4. A steam boiler tail gas waste heat water circulation heating system according to claim 1, characterized in that, The outer side of the preheating water tank is coated with a heat insulation layer.

5. A steam boiler tail gas waste heat water circulation heating system according to claim 1, characterized in that, A check valve is provided on the water pipe of the waste heat heating device leading to the preheating water tank.

6. The steam boiler tail gas residual heat water circulation heating system according to claim 1, characterized in that, The preheating water tank is respectively connected to multiple groups of boilers.

7. A waste heat water circulation heating system for the tail gas of a steam boiler according to claim 6, wherein Two groups of circulating water pumps, one main and one standby, are respectively provided at the water outlet end of the preheating water tank.

Images