CN204922936U - Low pressure economizer connected system - Google Patents

Abstract

The utility model discloses a low-pressure economizer connection system, which comprises: a first-stage low-pressure heater, a second-stage low-pressure heater, and a third-stage low-pressure heater connected in series, a booster pump and a low-pressure economizer; The water inlet of the first-stage low-pressure heater is connected to the water inlet of the booster water pump through a first valve, and the water outlet of the first-stage low-pressure heater is connected to the water inlet of the booster water pump through a second valve, The water outlet of the booster water pump is connected to the water inlet of the low-pressure economizer, the water outlet of the low-pressure economizer is connected to the water inlet of the third-stage low-pressure heater through the third valve, and the water outlet of the low-pressure economizer is connected to the water inlet of the third-stage low-pressure heater through the fourth valve. Water outlet connection for third stage low pressure heater. The utility model has beneficial effects: it can ensure the maximum energy-saving effect brought by the low-pressure economizer to the unit.

Description

Low Pressure Economizer Connection System

technical field

The utility model relates to the technical field of a low-pressure economizer of a steam turbine generator set, in particular to a connection system of a low-pressure economizer applied to a steam turbine generator set.

technical background

The low-pressure economizer is a device installed at the tail of the boiler to realize energy saving by recovering waste heat, and its connection system is an integral part of the thermal system of the steam turbine. At present, for the low-pressure economizer connection system with only three-stage low-pressure heaters, the condensed water is drawn from the inlet and outlet of the first-stage low-pressure heater respectively, and enters the low-pressure economizer after mixing, and the condensed water enters the low-pressure economizer. After absorbing heat, it is connected to the outlet of the last low-pressure heater.

The above-mentioned low-pressure economizer connection system can save energy most effectively only when the outlet water temperature of the low-pressure economizer is higher than the outlet water temperature of the last-stage low-pressure heater. If the boiler combustion changes or the heat exchanger of the low-pressure economizer accumulates dust, It may cause the outlet water temperature of the low-pressure economizer to decrease. Although the outlet water temperature of the low-pressure economizer can be increased by reducing the inlet water flow of the low-pressure economizer, it also increases the exhaust gas temperature of the boiler and reduces the heat absorption of the waste heat at the tail of the boiler. amount, thereby reducing the overall energy-saving effect of the low-pressure economizer on the unit.

Utility model content

The purpose of this utility model is to solve the above problems and provide a low-pressure economizer connection system. Energy savings are most effective at lower temperatures.

In order to achieve the above object, the utility model adopts the following technical solutions:

A low-pressure economizer connection system, comprising: several stages of low-pressure heaters, booster water pumps and low-pressure economizers connected in series; the water inlet of the first-stage low-pressure heater connects with the boost The water inlet of the water pump is connected, the water outlet of the first-stage low-pressure heater is connected with the water inlet of the booster water pump through the second valve, and the water outlet of the booster water pump is connected with the water inlet of the low-pressure economizer. The water outlet of the economizer is connected to the water inlet of the final low-pressure heater through the third valve, and the water outlet of the low-pressure economizer is connected to the water outlet of the last low-pressure heater through the fourth valve.

At least three stages of low pressure heaters are sequentially connected in series.

The last-stage low-temperature heater is connected with the deaerator.

The beneficial effects of the utility model are:

When the boiler combustion meets the design parameters of the low-pressure economizer and the heat exchange surface of the low-pressure economizer is kept clean, the outlet water temperature of the low-pressure economizer is slightly higher than the outlet water temperature of the last-stage low-pressure heater, and the outlet water of the low-pressure economizer is led to The water outlet of the last low-pressure heater;

When the combustion of the boiler changes or the heat exchange area of the low-pressure economizer is dusty, causing the outlet water temperature of the low-pressure economizer to be lower than the outlet water temperature of the last-stage low-pressure heater, the outlet water of the low-pressure economizer is led to the final stage. The water inlet of the last low-pressure heater.

The above two operating conditions can avoid the reduction of the heat absorption of the waste heat at the tail of the boiler, and ensure the maximum energy saving effect brought by the low pressure economizer to the unit.

Description of drawings

Fig. 1 is the structural representation of the utility model low pressure economizer connection system;

Among them, 1. #1 low-pressure heater; 2. #2 low-pressure heater; 3. #3 low-pressure heater; 4. Deaerator; 5. Low-pressure economizer; 6. Booster pump; 7. The first valve , 8. The second valve, 9. The fourth valve, 10. The third valve.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

It should be understood that the purpose of this utility model is to improve the structure of the low-pressure economizer connection system. Under the premise of ensuring the normal operation of the system, those skilled in the art can choose suitable low-pressure heaters, low-pressure economizers, Type of booster water pump and valves and connect them correctly.

The structure and method described in the utility model are suitable for low-pressure heaters with more than three stages connected in series, and those skilled in the art can reasonably select the stages of low-pressure heaters according to the actual situation. In this embodiment, taking 3 stages of low-pressure heaters connected in series as an example, the specific structure and working method of the present utility model are described in detail. Know.

As shown in Figure 1, a low-pressure economizer connection system applied to a turbogenerator set includes: #1 low-pressure heater 1, #2 low-pressure heater 2, #3 low-pressure heater 3, oxygen removal 4, the inlet and outlet of the #1 low-pressure heater are respectively connected to the inlet of the booster water pump 6 through the first valve 7 and the second valve 8, and the outlet of the booster water pump 6 is connected to the inlet of the low-pressure economizer 5, and the low-pressure economizer The outlet of the coal burner is connected with the outlet and the inlet of #3 low-pressure heater 3 through the fourth valve 9 and the third valve 10 respectively. #3 low pressure heater 3 is connected with deaerator.

The working mode of the low-pressure economizer connection system of the utility model is as follows:

The water temperature and flow rate entering the low-pressure economizer 5 are adjusted through the first valve 7 and the second valve 8 to ensure that the temperature of the inlet pipe wall of the low-pressure economizer 5 is higher than the minimum temperature designed by the manufacturer, such as 70°C (higher than this temperature ensures that the pipe wall No low-temperature corrosion), to ensure that the flue gas temperature at the outlet of the low-pressure economizer 5 is higher than the acid dew point temperature of the flue gas, such as 100°C. After the above adjustments, the heat absorption of the low-pressure economizer system in the flue at the tail of the boiler reaches the maximum value.

If the outlet water temperature of low-pressure economizer 5 is higher than the outlet water temperature of #3 low-pressure heater 3, close the third valve 10, open the fourth valve 9, and all the outlet water of low-pressure economizer 5 is led to the outlet of #3 low-pressure heater 3, At this time, the low-pressure economizer system can bring the greatest energy saving to the unit.

If the outlet water temperature of the low-pressure economizer 5 is lower than the outlet water temperature of the #3 low-pressure heater 3, close the fourth valve 9 and open the third valve 10, and all the outlet water of the low-pressure economizer 5 is led to the inlet of the #3 low-pressure heater 3, At this time, the low-pressure economizer system can bring the greatest energy saving to the unit.

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (3)

1. a low-pressure coal saver connected system, is characterized in that, comprising: the some grades of low-pressure heaters be sequentially connected in series, booster water pump and low-pressure coal saver; The water inlet of described first order low-pressure heater is connected with the water inlet of described booster water pump by the first valve, the delivery port of first order low-pressure heater is connected with the water inlet of described booster water pump by the second valve, the delivery port of described booster water pump is connected with low-pressure coal saver water inlet, low-pressure coal saver delivery port is connected by the water inlet of the 3rd valve with most final stage low-pressure heater, and low-pressure coal saver delivery port passes through the 4th valve and is connected with the delivery port of most final stage low-pressure heater.

2. a kind of low-pressure coal saver connected system as claimed in claim 1, it is characterized in that, at least three grades of low-pressure heaters are sequentially connected in series.

3. a kind of low-pressure coal saver connected system as claimed in claim 1, is characterized in that, described most end grade low-temp heater is connected with oxygen-eliminating device.