JPH0435680B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention particularly relates to a control device for a separate heat pipe that prevents the internal pressure from becoming a negative pressure.

Background Art Separate heat pipes are a type of heat exchanger, and are characterized by having separate evaporators and condensers for water, which is the heat exchange medium. Some systems consist of several sets of closed cycle units, each consisting of a separate evaporator, a condenser, and a circulating water pump that connects the two. Conventional control of such separate type heat pipes controls the gas temperature on the heating side and also controls the water level in the evaporator, and for this purpose, the circulating water flow rate control valve is used as the operating end. . However, when the gas temperature on the heating side decreases or the amount of heat exchange increases,
The internal pressure becomes negative, and as a result, air leaks in from outside the system, deteriorating heat exchange efficiency, and oxidation occurs within the system, causing deterioration.

As a countermeasure, it is possible to exhaust the air by using a vacuum pump or by drawing it into a negative pressure line, but this does not solve the problem since the air still leaks.

Problems to be Solved by the Invention This invention controls the internal pressure of a separate heat pipe to prevent it from becoming a negative pressure, thereby preventing deterioration of heat exchange efficiency and shortening of life due to oxidation within the system. The goal is to

Means for Solving the Problems The present invention provides a heat exchanger using a plurality of separate heat pipe units, in which a transmitter for detecting pressure is attached to the unit on the side where the internal pressure can become negative pressure. A control device that prevents the internal pressure from becoming negative pressure by increasing or decreasing the amount of circulating water in a heat pipe unit disposed upstream of the heat pipe unit in the gas flow on the heating side according to the output. be.

Effects According to this invention, when it is detected and transmitted that the internal pressure of the unit on the side where the pressure becomes negative has become negative pressure, the circulating water of the upstream unit is controlled and its heat exchange amount is reduced. The gas inlet temperature of the negative pressure side unit rises and returns to positive pressure.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. In the illustrated embodiment, the two-unit closed cycle includes an upstream evaporator 1A that absorbs heat on the upstream side of the exhaust gas 12, an upstream condenser 2A that radiates heat to the B gas 13, and an upstream circulating water control that connects the two. an exhaust gas upstream unit 14A comprising an upstream circulating water pump 3A equipped with a valve 4A;
and a downstream circulating water pump comprising a downstream evaporator 1B that absorbs heat on the downstream side of the exhaust gas, a downstream condenser 2B that radiates heat to the B gas, and a downstream circulating water control valve 4B that connects the two. It is composed of an exhaust gas downstream unit 14B consisting of 3B. 1A of both the upper and downstream evaporators,
1B is equipped with an upstream evaporator water level transmitter 5A and a downstream evaporator water level transmitter 5B, respectively. An upstream evaporator water level deviation controller 7A equipped with an upstream evaporator water level setting device 6A is connected to the upstream water level transmitter, and the deviation controller is connected to the upstream circulating water control valve. It is connected to the low selector 11 to be controlled. A downstream evaporator water level deviation controller 7B equipped with a downstream evaporator water level setting device 6B is connected to the downstream water level transmitter, and the deviation controller is connected to the downstream circulating water control valve. It's connected. Further, a downstream unit internal pressure transmitter 8 is installed in the downstream condenser, and the unit internal pressure transmitter 8 is connected to the low selector 11.
The internal pressure setting device 9 is connected to the pressure deviation controller 10 via a pressure deviation controller 10 attached thereto.

Therefore, normally, if the water level setter for both evaporators is set to a value that allows for the most efficient heat exchange, the upper and downstream evaporator water level deviation controllers will adjust the water level for both evaporators. The water level of the vessel will be controlled to the set value. That is, the signal from the downstream unit internal pressure transmitter 8 exceeds the signal from the internal pressure setting device 9 (usually set to atmospheric pressure), and the upper and downstream evaporator water level deviation adjustment types 7
A and 7B are saturated, so the low selector selects the signal from the upstream water surface level deviation controller, and the upstream unit 14A also performs level constant control.

However, when the temperature of the exhaust gas decreases, the temperature of the exhaust gas at the inlet of the downstream unit 14B naturally decreases, and the temperature of the circulating water also decreases, so that the output of the downstream chamber internal pressure transmitter 8 changes to the internal pressure setting device 9. As a result, the output of the pressure deviation controller 10 becomes lower than the output of the upstream evaporator water level deviation controller 7A, so the low selector 11 switches to pressure control and the downstream unit is prevented from becoming a negative pressure.

Note that even if the heat exchange in the upstream unit 14A is brought to zero, if the pressure in the downstream unit 14B still becomes negative, the downstream unit may be configured in the same manner as the upstream unit.

Furthermore, in the above explanation, the B gas 13 is heated by the exhaust gas 12, but the gas is on the heating side,
There is no problem as long as both sides to be heated are gas, and although the number of units has been described as two, it is needless to say in detail that the same effect can be obtained even if the number of units is three or more.

Effects of the Invention As described above, the present invention allows operation of a separate heat pipe without the internal pressure becoming negative pressure, and therefore reduces heat exchange efficiency due to air leakage caused by negative pressure. It is possible to avoid deterioration or shortening of life caused by in-system oxidation, and its industrial value is extremely high.

[Brief explanation of drawings]

The drawing is a system diagram showing an embodiment of the present invention. 1A...Upstream evaporator, 1B...Downstream evaporator, 2A...Upstream condenser, 2B...Downstream condenser, 3A...Upstream circulating water pump, 3B...Downstream circulating water pump, 4A...Upstream circulating water control valve, 4
B...Downstream circulating water control valve, 5A...Upstream evaporator water level transmitter, 5B...Downstream evaporator water level transmitter, 6A...Upstream evaporator water level setting device, 6B...Downstream Side evaporator water level setting device, 7A... Upstream evaporator water level deviation controller, 7B... Downstream evaporator water level deviation controller, 8... Downstream unit internal pressure transmitter, 9...
Internal pressure setting device, 10...Pressure deviation controller, 11...
...Low selector, 12...Exhaust gas, 13...B gas, 14A...Upstream unit, 14B...Downstream unit.

Claims (1)

[Claims] 1 In a heat exchange device that uses multiple separate heat pipe units, a transmitter that detects pressure is attached to the unit on the side where the internal pressure can become negative pressure, and depending on the output of this transmitter, the unit on the heating side is A control device that prevents the internal pressure from becoming a negative pressure by increasing or decreasing the amount of circulating water in a heat pipe unit disposed upstream in the gas flow.