JPH0442620Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a temperature control valve used for temperature control of hot water tanks, heat exchangers, etc.

(Prior art) For example, when steam or hot water is sent to a heat exchanger to make hot water from cold water, the supply of steam or hot water is restricted or stopped when the temperature is above a predetermined temperature in order to keep the hot water at a nearly constant temperature. When the temperature is below a predetermined temperature, it is necessary to start or increase the supply of steam or hot water. For this purpose, a temperature regulating valve that automatically operates depending on the hot water temperature is installed in the pipeline that sends steam or hot water to the heat exchanger. Classified into direct-acting single-seat structures with a single main valve body, direct-acting double-seat structures with two main valve bodies, and pilot-type valves with pilot valve bodies. be done.

6, 7, and 8 are cross-sectional views schematically showing conventional temperature regulating valves, in which a heat-sensitive tube 51 containing a chemical solution for steam generation and a driving member 52 generally made of a bellows are shown. communicate with each other through a lead pipe 53,
The proximal end of a valve rod 54 is fixed to the distal end surface of the drive member 52, and a return spring 55 acts.
Then, when the target fluid such as hot water is heated to around a predetermined temperature and the chemical liquid generates steam, the drive member 52 moves the valve stem 54 downward in the drawing due to the pressure, and when the chemical liquid condenses, the valve stem is returned by the action of the spring 55. 54 is moved upward, and this movement controls the flow rate of control fluid such as steam or hot water.

(Problem to be solved by the invention) The direct acting single-seat structure and double-seat structure shown in FIGS. 6 and 7 have a single main valve body 56 or two main valves with different effective areas on the valve stem 54. Since the drive member 52 and the main valve bodies 56, 57, 58 are directly connected to each other, control from a minute flow rate to a maximum flow rate is possible. However, with single-seat structures, the maximum flow rate is generally 0.01 to 0.05% due to leakage from around the main valve body 56 when the valve is closed.
Although it is extremely small and allows precise control of the flow rate, it requires a driving force proportional to the effective area of the main valve body 56, so it sacrifices the maximum flow rate to reduce the effective area and operates with a small driving force. There is a problem in that either the driving member 52 must be made larger or the drive member 52 must be made larger. In addition, since the two-seat structure can operate with a driving force proportional to the difference in effective area between the two main valve bodies 57 and 58, it has the advantage that it can operate even if the driving member 52 is made smaller, and the maximum flow rate can be increased. However, when the valve is closed, leakage from around the main valve bodies 57, 58 is unavoidable, and the flow rate is generally about 0.5 to 1% of the maximum flow rate.

The pilot type shown in FIG. 8 has a valve stem 54.
The pilot valve body 59 opens and closes following the movement of the piston, thereby controlling the primary side fluid pressure acting on the back chamber 61 of the piston 60 and opening and closing the main valve body 62. 59, the main valve body 62 is operated only by the differential pressure between the primary side fluid pressure and the piston back pressure. Therefore, it is impossible to make the pilot valve respond quickly to sudden changes in differential pressure that act around the time the valve starts opening, and an unstable region of operation is unavoidable. Not only is it impossible to precisely control the flow rate as it is necessary to regulate the flow rate to about 10%, but also because the pilot valve and the main valve are separated, an accident may occur in which the main valve body 62 opens due to leakage from the pilot valve.

Therefore, in view of these problems, the present invention was devised for the purpose of providing a temperature regulating valve that has less leakage from the main valve body, can increase the maximum flow rate, and can be opened and closed with a small driving force. It is something.

(Means for Solving the Problems) According to the present invention, the heat-sensitive tube in which a chemical solution for steam generation is sealed and the drive member communicate with each other, and a return spring that resists steam pressure is attached to the drive member. In a temperature regulating valve which is functioning and has a single main valve element which cooperates with a single main valve seat to open and close the flow path of the control fluid; A sub-valve including a valve chamber and a sub-valve seat that opens the sub-valve chamber to the secondary side of the flow path is provided in the main valve body; the sub-valve chamber is provided in the main valve body. The first passage hole and the second passage hole communicate with the primary side of the flow path and the back chamber of the main valve body, respectively; the driving member and the sub-valve body are connected by a valve rod to open the valve. When the valve is closed, the auxiliary valve is opened first and then the main valve is opened, and when the valve is closed, the main valve is closed first and then the auxiliary valve is closed.

(Function) When the temperature of the target fluid is considerably lower than the set temperature, the main valve and sub-valve are fully open due to the action of the return spring.
The control fluid flows through the flow path at the maximum flow rate, and the pressure in the back chamber of the main valve body is approximately the same as that on the secondary side of the flow path.

When the temperature of the target fluid approaches the set temperature and the vapor pressure of the chemical liquid increases, the driving member overcomes the spring force of the returning spring and moves the sub-valve body and the main valve body together in the valve-closing direction. When the main valve element approaches full closure, the pressure on the secondary side decreases, and the main valve element moves ahead of the auxiliary valve element due to the pressure in the back chamber, seats on the main valve seat, and closes the valve. Thereafter, the sub-valve element is seated on the sub-valve seat and the valve is closed.

When the temperature of the target fluid becomes lower than the set temperature, the auxiliary valve is moved by the spring force of the return spring to open the auxiliary valve, and it is introduced into the back chamber through the primary and secondary holes when the valve is closed. The primary fluid is discharged to the secondary side.
Further, when the sub-valve body moves, the main valve body is moved together with the main valve body in the valve-opening direction, thereby opening the main valve.

(Embodiment) An embodiment of the present invention will be described based on the drawings.The temperature regulating valve of the present invention is constructed by a heat-sensitive cylinder 1 and a lead pipe 2, which are filled with a chemical solution that evaporates or condenses depending on the temperature of the target fluid. A driving part 5 is provided with a driving member 3 made of a bellows and a return spring 4, which are connected to each other by a bellows, and is opened and closed by the force of this driving part 5 and the differential pressure of the control fluid to control the flow rate of the control fluid. It is composed of a main valve 6 and a sub-valve 7 which is opened and closed by the drive section 5 to adjust the pressure of the main valve operation and control the flow rate at minute flow rates.

The control fluid flow path 9 formed inside the main valve body 8 of the main valve 6 has an upwardly facing seat portion 10a in the middle, and the control fluid is supplied from the upstream primary passage _9A to the downstream secondary passage _9B . A main valve seat 10 is provided which has a main valve seat opening 10b through which the main valve seat 10b passes, and a main valve body 11 that seats on the seat portion 10a or is spaced apart from this and closes or opens the main valve seat opening 10b is provided. It is installed on the Aisle _9A side. The main valve body 11 consists of a main body 11a and a lid body 11b, which have a part that seats on the seat part 10a and a part that is fitted into the cylindrical guide part 12 formed in the main valve main body 8,
It is equipped with a sub-valve 7.

The sub-valve 7 has a sub-valve chamber 14 formed between the main body 11a and the lid 11b, and a sub-valve seat 15 having a sub-valve seat opening 15b that opens the sub-valve chamber 14 toward the main valve seat opening 10b. and a sub-valve body 16 built into the sub-valve chamber 14 and in contact with or separated from the seat portion 15a of the sub-valve seat 15. The primary passage 9 _A and the back chamber 19 formed on the opposite side of the main valve seat 10 of the main valve body 11 communicate through the first passage hole 17 and the second passage hole 18 having a larger diameter. .

An upper body 20 is stacked on top of the main valve body 8, and the base of the drive member 3 is fixed to the lower surface of the top wall of the cover body 21 stacked on top of the upper body 20. The body 16 is fixed to both ends of a valve stem 22 that extends in the rigid direction, so that the valve stem 22 and the body 16 operate together. The valve stem 22 penetrates the top of the main valve body 8 in a liquid-tight or air-tight manner by means of a sealing material 23 and also passes through a guide tube 24 provided on the upper body 20. A coiled return spring 4 is inserted between the drive member 3 and a spring receiver 26 superimposed on a nut 25 screwed into the screw, and its initial load can be adjusted by the nut 25.

Next, the operation of this embodiment according to the above configuration will be explained.

When the temperature of the target fluid is considerably lower than the set temperature, such as at the start of operation, the heat-sensitive tube 1 in contact with the target fluid
The chemical liquid is condensed and the pressure inside the drive member 3 is low, and the spring force of the return spring 4 pulls up the sub-valve body 16, fully opening the sub-valve seat opening 15b, and causing a sub-valve on the bottom surface of the lid body 11b. By pulling up the main valve body 11 together with the valve body 16, the main valve seat opening 10
b is fully open (see Figure 2). Therefore, the maximum flow rate of control fluid flows from the primary passage _9A to the secondary passage _9B . In addition, the back chamber 19 is connected to the main valve seat opening 10b by the sub-valve seat opening 15b, the sub-valve chamber 14, and the second through hole 18.
Since the first through hole 17 has a small diameter, the pressure is approximately the same as the pressure on the secondary side of the flow path 9.

When the temperature of the target fluid rises and approaches the set temperature, a part of the chemical liquid in the thermosensitive tube 1 evaporates, gradually increasing the evaporation pressure, which is introduced into the drive member 3 through the lead pipe 2 and is applied by the spring force of the return spring 4. Uchikante Benbo 22
will move downward. Therefore, the sub-valve body 16 is pushed down, but the secondary side of the flow path 9 and the back chamber 1
9 have almost the same pressure, so by designing the main valve body 11 so that the downward force due to these pressures is slightly larger than the upward force, the main valve body 11 mainly uses its own weight. As a result, the sub-valve element 16 and the main valve element 11 move almost integrally in the closing direction of the main valve 6 (see FIG. 3). When the temperature of the target fluid further rises to the set temperature and the main valve body 11 approaches fully closed, the pressure on the secondary side of the flow path 9 decreases, the differential pressure with the back chamber 19 increases, and the main valve body 11 closes completely. It descends in advance of the sub-valve element 16 by a distance behind the valve element 16 and is seated on the seat portion 10a of the main valve seat 10. As a result, the primary passage 9 _A and the secondary passage 9 _B of the flow path 9 are substantially blocked, and then the sub-valve body 16 is seated on the seat portion 15 a of the sub-valve seat 15 and the valve is completely closed. Yes (see Figure 4).

In the valve closed state, primary side pressure is introduced into the back chamber 19 through the first passage hole 17, the sub-valve chamber 14, and the second passage hole 18, and applies a valve-closing force to the main valve body 11.

When the temperature of the target fluid becomes lower than the set temperature due to restriction or stoppage of the control fluid supply,
The chemical vapor begins to condense, reducing the vapor pressure, and when the downward force of the driving member 3 is overcome by the spring force of the spring 4, the valve stem 22 is moved upward. For this reason, the sub-valve body 16 is pulled up and the sub-valve seat opening 15b is opened, and the primary side pressure introduced into the back chamber 19 is transferred to the second passage hole 18, the sub-valve chamber 14, and the sub-valve seat opening 1.
5b to the secondary side of the flow path 9, but the main valve body 1
Since the pressure acting on the main valve body 11 is designed so that the downward force is larger as described above, the main valve body 11 remains seated on the seat portion 10a. When the vapor pressure of the chemical liquid further decreases, the sub-valve body 16 closes to the lid body 1.
1b, that is, the top surface of the auxiliary valve chamber 14, pulls up the main valve body 11 together, opens the main valve seat 10b, and starts supplying control fluid (see Fig. 5) (Effect of the invention) According to this invention, since the sub-valve is built into the main valve body of the main valve with a single-seat structure, there is extremely little leakage when the valve is closed compared to the two-seat structure or pilot type, and the flow rate can be controlled precisely. Control is possible.
In addition, the main valve operation can be controlled by operating the sub-valve using the vapor pressure of the chemical solution and the force of the return spring, and by setting the fluid pressure in the back chamber of the main valve body to either the primary pressure or the secondary pressure. The pressure is adjusted, and the main valve body is closed by the differential pressure between the top and bottom of the main valve body and its own weight, and the valve is opened by the spring force of the return spring, so it can be operated with extremely small driving force. The members can be made smaller, and the effective area of the main valve body can be increased to increase the maximum flow rate. Furthermore, even if the sub-valve opens when the main valve opens, it does not open immediately, but starts opening depending on the balance between the pressure difference between the upper and lower parts of the main valve body and the pulling force of the sub-valve body. Precise flow rate control is achieved by stable operation without creating an unstable region in the flow rate range.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention;
Figures 3, 4, and 5 are enlarged vertical cross-sectional partial views for explaining the operation, and Figures 6, 7, and 8 are schematic cross-sectional views of conventional products. DESCRIPTION OF SYMBOLS 1...Thermosensitive tube, 3...Driving member, 4...Return spring, 5...Driving section, 6...Main valve, 7...Sub-valve, 9
...Flow path, 10...Main valve seat, 11...Main valve body, 1
4...Sub-valve chamber, 15...Sub-valve seat, 16...Sub-valve body, 17...First passage hole, 18...Second passage hole, 19
...Back chamber, 22...Valve stem.

Claims (1)

[Claims for Utility Model Registration] A heat-sensitive cylinder 1 in which a chemical solution for steam generation is sealed and a driving member 3 are in communication with each other, and a return spring 4 that opposes steam pressure acts on the driving member 3. In a temperature regulating valve in which the main valve 6 includes a single main valve element 11 that cooperates with a single main valve seat 10 to open and close the control fluid flow path 9; A built-in sub-valve chamber 14 and a sub-valve seat 15 that opens the sub-valve chamber 14 to the secondary side of the flow path 9
A sub-valve 7 is provided in the main valve body 11; 9
The driving member 3 and the auxiliary valve body 16 communicate with the primary side of the main valve body 11 and the back chamber 19 of the main valve body 11;
When the valve is opened, the auxiliary valve 7 is opened, and then the main valve 6 is opened; when the valve is closed, the main valve 6 is closed first, and then the auxiliary valve 7 is closed; Temperature regulating valve that is configured.