Chemical solution injection system and chemical solution injection method

Patent metadata

Field	Value
Publication number	US-2016372219-A1
Application number	US-201414587223-A
Country	US
Kind code	A1
Filing date	Dec 31, 2014
Priority date	Jan 21, 2014
Publication date	Dec 22, 2016
Grant date	—

Abstract

A chemical solution injection system 30 of an embodiment includes: a chemical solution reservoir 31 that stores a chemical solution containing a depositing substance to deposit to a member in contact with cooling water for absorbing heat in a plant; a pipe 32 through which the chemical solution passes; a first heat exchanger and a second heat exchanger that exchange heat between the cooling water and the chemical solution; a cooling water pipe 49 which connects the heat exchangers in series and in which the cooling water passes; and a pump 34 that conveys the chemical solution. The temperature of the chemical solution in the chemical solution reservoir 31 is lower than that of the cooling water. The pipe 32 sequentially connects the chemical solution reservoir 31, the first heat exchanger, the second heat exchanger and the plant. The cooling water guided from the inside of the plant passes through the second heat exchanger and subsequently passes through the first heat exchanger. The chemical solution passes through the first heat exchanger and subsequently passes through the second heat exchanger.

First claim

What is claimed is:

1 . A chemical solution injection system, comprising:
a chemical solution reservoir which stores a chemical solution containing a depositing substance to deposit to a member in contact with cooling water circulating in a plant and having a lower temperature than the cooling water has; a pipe through which the chemical solution supplied from the chemical solution reservoir passes; a plurality of heat exchangers which exchange heat between the cooling water and the chemical solution passing through the pipe; a cooling water pipe which connects the heat exchangers in series and through which the cooling water guided from an inside of the plant flows; and a pump which conveys the chemical solution through the pipe, wherein the chemical solution flows in an order of the chemical solution reservoir, the heat exchanger on an upstream side, the heat exchanger on a downstream side, and the plant, and the cooling water passes through in an order of the heat exchanger on the downstream side and the heat exchanger on the upstream side while heating the chemical solution to reduce a difference in temperature between the chemical solution and the cooling water.

2 . The chemical solution injection system according to claim 1 , wherein both ends of each of the plurality of heat exchangers into and from which the chemical solution flows are provided with valves subjected to open and close control, and the chemical solution passes through the plurality of heat exchangers in series or in parallel according to setting of the valves.

3 . The chemical solution injection system according to claim 2 , further comprising a bypass pipe which bypasses both the ends so as to prevent the chemical solution from passing through the plurality of heat exchangers.

4 . The chemical solution injection system according to claim 2 , further comprising:
a first confluence section which causes the chemical solution to join from the heat exchanger on the downstream side among the plurality of heat exchangers into a high temperature region of the plant; and a second confluence section which causes the chemical solution to join from a heat exchanger different from the heat exchanger on the downstream side among the plurality of heat exchangers into the high temperature region of the plant.

5 . The chemical solution injection system according to claim 1 ,
wherein the pipe is provided with a chemical solution injection control valve which controls an inflow of the chemical solution into the cooling water in the plant, a thermometer which measures a temperature of the chemical solution flowing through the pipe, and a chemical solution injection controller which controls opening and closing of the chemical solution injection control valve, based on measurement by the thermometer.

6 . The chemical solution injection system according to claim 5 ,
wherein the chemical solution is a colloidal solution of titanium oxide, and when a difference in temperature between the chemical solution and the cooling water is 50□ C or less, the chemical solution injection controller opens the chemical solution injection control valve.

7 . The chemical solution injection system according to claim 5 ,
wherein the chemical solution is a colloidal solution of titanium oxide, and when the temperature of the chemical solution reaches a temperature allowing a temperature change of the chemical solution injected into the cooling water to be within 10□ C/s, the chemical solution injection controller opens the chemical solution injection control valve.

8 . The chemical solution injection system according to claim 1 , further comprising:
a concentration measurement unit which measures a concentration of the chemical solution in the cooling water in the plant; and a controller for an amount of chemical solution supply which controls the amount of chemical solution supply from the chemical solution reservoir to the pipe based on measurement by the concentration measurement unit.

9 . A chemical solution injection method, comprising:
a step of storing a chemical solution containing a depositing substance to deposit to a member in contact with cooling water circulating in a plant and having a lower temperature than the cooling water has; a step of causing the chemical solution to flow in an order of a chemical solution reservoir, a pipe communicating with the chemical solution reservoir, a heat exchanger on an upstream side and a heat exchanger on a downstream side among a plurality of heat exchangers connected to each other in series, and the plant; a step of causing the cooling water to pass through in an order of the heat exchanger on the downstream side and the heat exchanger on the upstream side while heating the chemical solution to reduce a difference in temperature between the chemical solution and the cooling water; and a step of injecting the heated chemical solution into the cooling water in the plant.

Assignees

• Toshiba Kk

Inventors

• Okamura Masato
• Oosato Tetsuo
• Yamamoto Seiji
• Arai Hiroyuki
• Shibasaki Osamu
• Negishi Koji
• Koga Hiromichi

Classifications

• C23F11/187

  Mixtures of inorganic inhibitors · CPC title

• F22B37/025

  Devices and methods for diminishing corrosion, e.g. by preventing cooling beneath the dew point · CPC title

• C23F11/00

  Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent (adding inhibitors to mineral oil, fuels, or lubricants C10; adding inhibitors to pickling solutions C23G) · CPC title

• F22B37/04

  and characterised by material, e.g. use of special steel alloy · CPC title

• G21C19/28

  Arrangements for introducing fluent material into the reactor core; Arrangements for removing fluent material from the reactor core (pumping coolant G21D) · CPC title