CN203336126U - Heat tracing and washing system of urea solution conveying pipeline - Google Patents

Abstract

The utility model provides a heat tracing and washing system of a urea solution conveying pipeline. The heat tracing and washing system of the urea solution conveying pipeline comprises a water supplying system, a heat tracing water cylinder, a heat tracing pipeline and a washing water pipe, wherein the water supplying system conveys warm water at proper temperature to the heat tracing water cylinder; an output port of the hot tracing water cylinder is connected with an input port of itself through the heat tracing pipeline, a heat tracing water pump and a valve to form a circulating loop, a branch stretched out of the heat tracing pipeline in a urea metering control module area serves as the washing water pipe, the washing water pipe is connected with an input port of a metering control module of the urea solution conveying pipeline, and a water draining pipe is connected with a sewage draining port of the metering control module to drain sewage out. The heat tracing and washing system of the urea solution conveying pipeline has the advantages that a heat tracing source of the urea solution long-distance conveying pipeline is stable and reliable, meanwhile, a washing system of the urea metering control module is simplified, and a reliable guarantee is provided for stable operation of a boiler flue gas denitration system.

Description

Heat tracing and flushing system for urea solution delivery pipeline

technical field

The utility model relates to a pipeline heat tracing technology, in particular to a heat tracing and flushing pipeline of a urea solution delivery pipeline.

Background technique

When the flue gas denitrification system uses urea as the reducing agent, the concentration of the urea solution is usually 50-60%, and the crystallization temperature of the 50% urea solution is 16.7°C, and when the temperature of the urea solution exceeds 60°C, hydrolysis begins to occur and NH ₃ is formed and CO ₂ , affecting system safety. Therefore, it is necessary to configure a stable and sufficient heat source during the transportation of urea solution to keep the temperature of urea solution between 30-40°C. The heating system of the urea solution delivery pipeline needs to ensure a stable temperature of the urea solution to avoid crystallization or overheating of the urea solution. When the urea solution delivery pipeline is traced by the steam pipeline system, the following problems mainly exist: 1. When using the usual single steam source for heat tracing, in order to ensure the heat tracing effect at the end of the system, steam with higher parameters must be used, and too high High temperature steam will cause hydrolysis of the urea solution in the pipeline. 2. The use of multi-point air source heat tracing will result in many steam supply points in the system. The steam heat tracing needs to be equipped with a separate drainage recovery system, and the entire steam heat tracing system has complicated pipelines. The metering control module of the urea pyrolysis system of each unit is equipped with a separate set of flushing water system, which will also result in a large investment in equipment and a complex system. In addition, the urea solution metering control module is the core equipment of the urea pyrolysis system. When the pyrolysis system fails or shuts down, the interior of the control module needs to be fully cleaned, so flushing water pipes need to be installed and the metering control module introduced.

According to the usual design, the urea solution pipeline is laid in parallel with steam pipelines as heat tracing, and the metering control module is separately equipped with flushing water pipelines. Douhe Power Plant has six units. If flushing water pipelines are installed separately, the piping system of the entire denitrification system will be complicated, and the pipeline laying distance will be long, and the resource consumption will be large, which does not meet the energy-saving requirements.

Contents of the invention

In order to solve the deficiencies in the prior art, the utility model provides a new heat tracing and flushing system for urea solution delivery pipelines, which is a pipeline system that can provide stable heat tracing temperature and also has a flushing function.

The utility model is accomplished by adopting the following technical solutions:

A heating and flushing system for a urea solution delivery pipeline, including a water supply system, a heating water tank, a heating pipeline and a flushing water pipe, the water supply system delivers moderately warm water to the heating water tank; the output port of the heating heating tank passes through The heating pipe is connected with its own input port through the heating water pump and valve to form a circulation loop. In the area of the urea metering control module, a branch is drawn from the heating pipe as a flushing water pipe. The flushing water pipe is connected to the input port of the metering control module of the urea solution delivery pipeline, and the drain pipe is connected to the sewage outlet of the metering control module to discharge the waste water.

Urea solution hot water heating system has the following advantages:

1. The heating temperature is stable and easy to adjust.

2. With hot water recycling, the urea solution preparation tank and storage tank heater are collected to drain water and save water.

3. The lead-out branch of the hot water is used as the flushing water of the metering control module, which simplifies the system, saves investment, and facilitates maintenance.

Description of drawings

Fig. 1 is a schematic diagram of the delivery state of urea solution;

Figure 2 is a schematic diagram of the flushing state;

Figure 3 is a multi-target heat tracing flushing pipeline diagram;

In the figure: water supply system 1, heating water tank 2, heating water pump 3, heating pipe 4, urea solution delivery pipe 5, flushing water pipe 6, metering control module 7, valve 8.

Detailed ways

The utility model is described in detail below in conjunction with the accompanying drawings: a heat tracing and flushing system of a urea solution delivery pipeline, including a water supply system 1, a heat tracing water tank 2, a heat tracing pipeline 4 and a flushing water pipe 6. The hot water tank 2 transports cold water; the cold water is heated in the heating water tank 2; the output port of the heating water tank 2 is connected to its own input port through the heating pipe 4, the heating water pump 3 and the valve 8 to form a circulation loop. In the area of the urea pipeline metering control module, a branch is drawn from the heating pipe 4 as the flushing water pipe 6. The flushing water pipe 6 is connected to the input port of the metering control module 7, and the drain pipe is connected to the sewage outlet of the metering control module 7 to discharge waste water.

The heat tracing pipeline 4 is laid in parallel with the urea solution delivery pipeline 5, and the outside is covered with thermal insulation and aluminum skin. The heating pipeline 4 and the urea solution delivery pipeline 5 lead out from the urea solution preparation area, enter the vicinity of the boilers of each unit along the pipe support, and then return to the urea solution preparation area along the pipe support, and the hot water and urea solution enter the heating water tank and urea solution respectively. Solution storage tank. form a closed circulatory system. The circulation system is equipped with interfaces in the boiler area, and the hot water and urea solution pipelines of each boiler are arranged in parallel.

The heating pipe leads a branch in the area of the metering control module to connect to the metering control module. When the metering control module needs to be flushed, the valve is opened and the flushing water pipe is connected for flushing for 300 seconds, and the valve is closed.

Due to the circulating use of hot water, if there is no leakage in the system, there is almost no consumption. The metering control module will only flush when the equipment fails or the system is shut down, so the actual water consumption of the system is very small. In addition, considering that there is long-term hot water in the pipeline, In order to avoid scaling of pipes, the heating water can be designed to use deionized water.

The water supply system adopts water adding pipes and steam pipes, and a temperature measuring device is installed on the heating water tank, and the temperature of the hot water in the tank is controlled by adjusting the valve through the steam pipe.

As shown in Figure 3, the utility model can work on multiple heat tracing and flushing units at the same time, save resources to the greatest extent, and have good use effect.

This design solves the problem of stable and reliable heating source for long-distance transportation of urea solution, simplifies the flushing system of urea metering control module, and provides guarantee for the stable operation of boiler flue gas denitrification system.

Claims (1)

1. A heat tracing and flushing system of a urea solution delivery pipeline is characterized in that: it includes a water supply system, a heat tracing tank, a heat tracing pipeline and a flushing water pipe, and the water supply system delivers moderately warm water to the heat tracing tank; The output port of the hot water tank is connected to its own input port through the heat tracing pipe through the heat tracing pump and valve to form a circulation loop; a branch is drawn from the heat tracing pipe in the area of the urea metering control module as a flushing water pipe, and the flushing water pipe is connected with the urea solution The input port of the metering control module of the delivery pipeline is connected, and the drain pipe is connected with the sewage outlet of the metering control module to discharge the waste water.

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