JPS61252493A - Control unit of separate type heat pipe - Google Patents

Abstract

PURPOSE:To minutely adjust a heat-exchange mediums of respective units to respective reference flow quantities by calculating the optimal distribution quantity of the heat exchange quantity with respect to a unit from the external condition and maintenance of a high controllability. CONSTITUTION:The requested heat exchange quantity is calculated from signals from a B gas transmitter 9, a B gas flow quantity transmitter 10, an exhaust gas temperature transmitter 11, and an exhaust gas flow quantity transmitter 12 by use of a function 13. By use of a signal from the function 13 the reference flow quantities with respect to respective units are set by functions 14A and 14B. The flow quantities are determined so that respective units are prevented from utilized in a region where the controllability is poor and the negative pressure operation is not carried out. The reference flow quantities are added to signals from water level deviation adjusting meters 7A and 7B of an evaporator. The opening degrees of circulating water control valves 4A and 4B are controlled by the adding signals.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a control device that optimally distributes the heat exchange amount of a separate heat pipe, and is applicable to a field where heat exchange of exhaust gas is performed using a plurality of heat exchange means. can be used.

Background Art Separate heat pipes are a type of heat exchanger, and are characterized in that an evaporator and a condenser for water, which is a heat exchange medium, are provided separately. A heat pipe system consists of several sets of closed cycle units, each consisting of a separate evaporator and condenser and a circulating water pump connecting them.

Controlling the heat exchange amount of conventional separate heat pipes is
It controls the heating side gas temperature and the water level in the evaporator, and uses the circulating water flow rate control valve as the operating end.

Problems to be Solved by the Invention However, in a system consisting of multiple units, even if the external conditions (temperature and flow rate at the inlet of the heating side gas and heated side gas) are constant, there are multiple balance points. do. For example, if the total amount of heat exchanged in a system consisting of three units is set to "6", the amount of heat exchanged in each unit may be distributed as "3:2:IJ" or "2:
The distribution may be 2:2. Therefore, the conventional system in which each unit independently operates to achieve a control objective has the following drawbacks.

(1) Some units are operated in areas with poor control performance, where the amount of heat exchange is too large or too small.

(2) The heating side gas temperature may be cooled too much in the upstream unit and the downstream unit may become under negative pressure.

In this case, air leakage occurs, resulting in poor heat exchange efficiency and shortened life due to oxidation within the system.

The present invention has been made in view of the above circumstances, and an object of the present invention is to optimally allocate the amount of heat exchanged in a separate heat pipe consisting of a plurality of units.

Means for Solving the Problems According to the present invention, in a separate heat pipe system including a plurality of heat exchange units, in consideration of system external conditions, prevention of negative pressure operation, and maintenance of high controllability,
The optimum distribution amount of the heat exchange amount to each unit is calculated, and the heat exchange medium of each unit is finely adjusted to the respective reference flow rate.

Embodiment The drawings show a control system of a control device according to the present invention together with the configuration of a separate heat pipe.

The separate type heat pipe has evaporators IA and IB, two condensers, and 2B, respectively, and a circulating water pump 3A and a circulating water control valve 4A are provided between the evaporators IA and the two condensers, and A circulating water pump 3B and a circulating water control valve 4B are provided between the evaporator IB and the condenser 2B. In the illustrated example, the B gas is heated by the exhaust gas for convenience, but the gas is heated on the heating side,
On both sides to be heated, any gas may be used. Also, the closed cycle showed 2 units, but 3 units.
It may be more than one unit.

Evaporators IA and IB are provided with evaporator water level transmitters 5A and 5B, the outputs of which are connected to evaporator water level deviation controllers 7A and 7B together with the outputs of evaporator water level setters 6A and 6B, These outputs are sent to adder 8A,
8B respectively.

A B gas temperature transmitter 9 and a B gas flow rate oscillator 10 are provided upstream of the heated side heat pipe, and an exhaust gas temperature transmitter 11 and an exhaust gas flow rate transmitter 12 are also provided upstream of the heating side heat pipe. .

The output of each of these transmitters is connected to a function 13 that calculates the amount of heat exchange required of the heat pipe system. In the illustrated example, four output signals from the transmitters 9.1o and 11.12 are used, but the present invention is not limited to this as long as the signals can calculate the amount of heat exchange. For example, when applied to a boiler plant, the heat exchange amount can be calculated from the boiler load and exhaust gas temperature. Function 13
The output of is the function 1 that calculates the reference flow rate for each unit.
4A and 14B, these outputs are connected to adder 8A
.

8B respectively.

The amount of heat exchange required for the working system depends on the external conditions of the system,
That is, the B gas temperature transmitter 9, the B gas flow rate transmitter 10,
It is calculated using the signals of the exhaust gas temperature transmitter 11 and the exhaust gas flow rate transmitter 12 and the function 13. Using the signal from the function 13, the reference flow rate for each unit is set by functions 14A and 14B. This reference flow rate is determined to prevent each unit from operating in a region with poor controllability or from operating under negative pressure. The optimal reference flow rates for each unit are added by adders 8A and 8B to signals from the evaporator water level deviation controllers 7A and 7B, which are feedback signals for fine adjustment. Circulating water control valve 4 according to the addition signal
The opening degrees of A and 4B are operated.

In this example, an example of constant level control is given, but the same applies to outlet exhaust gas temperature control.

Effects of the Invention In a separate heat pipe system including multiple heat exchange units, there are multiple balance points, so in a conventional system where each unit operates individually,
Some units had poor controllability or were operated under negative pressure, but according to the present invention, the balance point of each unit can be limited to a convenient point for operation, so the above drawbacks can be overcome. It can be resolved.

Furthermore, since the required heat exchange amount is calculated based on the system external conditions, there is no need to change operating conditions in advance, and control coordination is significantly improved.

[Brief explanation of the drawing]

The drawing is a diagram showing a system of a control device according to the present invention together with a configuration of a separate heat pipe. IA, IB・Evaporator, 2A, 2Bφ・Condenser, 3A,
3Bφ・Circulating water pump, 4A, 4B・・Circulating water control pump, 5A, 5B-Evaporator water level transmitter, 6A, 6
B...Evaporator water level setting device, 7A. 7B...Evaporator water level deviation controller, 8A, 8B...
Adder, 9...B gas temperature transmitter, IO...B gas flow rate transmitter, 11...Exhaust gas temperature transmitter, 12...Exhaust gas flow rate transmitter, 13, 14A, 14B -- (1 other person)

Claims (1)

[Claims] A plurality of heat exchange units are installed between the separated heat pipes, and each unit is composed of an evaporator, a condenser, a circulating water pump, and a circulating water flow rate control valve. In the control device that performs the A separate type heat pipe control device comprising means for adjusting the control system of each circulating water flow rate control valve.