JPH0794958B2 - Temperature control device for heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to transfer of heat energy of a primary fluid such as a heat medium or a refrigerant to a secondary fluid by heat exchange through a heat exchanger. The present invention relates to a temperature adjusting device for a heat exchanger, which controls the flow rate of the primary fluid of the heat exchanger in relation to the flow rate of the secondary fluid in order to maintain the temperature of the secondary fluid within a desired range.

[Conventional technology]

In a district heating system or the like, there is a means for heating the secondary side fluid to be heated by the heat medium on the heating side, that is, the primary side fluid through the heat exchanger to raise the temperature of the secondary side fluid to a predetermined temperature. Has been adopted. In this case, there is a problem that the temperature of the secondary fluid decreases as the flow rate of the secondary fluid increases. To prevent this temperature decrease, the flow rate of the primary fluid on the heating side is increased, that is, the heat exchanger. It is necessary to increase the heat energy supplied to. Therefore, a temperature adjusting device for a heat exchanger is used.

The conventional temperature adjusting device for a heat exchanger is provided with a temperature adjusting valve in the primary side flow path on the heating side, and this temperature adjusting valve detects the temperature of the secondary side fluid and changes the primary temperature according to this temperature change. It is configured to control the flow rate of the side fluid. However, the temperature detecting means generally has a large follow-up delay with respect to the temperature change,
Especially, when the flow rate of the secondary fluid fluctuates greatly, there is a problem that the deviation from the set temperature becomes too large.

In addition, it has the characteristic that it operates so as to open the temperature control valve when the detected temperature is low. Therefore, when not in use, the temperature of the fluid in the detection part is low, so the temperature control valve is opened and the primary side fluid flows. Will continue. For this reason,
There is a problem that unnecessary heat consumption occurs, and a separate on-off valve must be installed to avoid this.

Conventionally, there is also a pressure reducing control valve that controls the flow rate of the primary side fluid in relation to the pressure of the secondary side fluid. However, such a pressure reducing control valve changes temperature with pressure fluctuation. Is too large, the stability of temperature control is impaired.

In order to solve the above-mentioned problems, there is a proposal (JP-A-52-112152) in which the primary side fluid flow rate is automatically controlled in relation to the secondary side fluid flow rate.

This proposal, as shown in FIGS. 4 and 5,
Flow rate adjusting means b provided in the primary side flow path of the heat exchanger a
And the flow rate sensing means c provided in the secondary side flow path are mechanically directly connected to each other. Then, when the flow rate of the secondary side fluid increases, the pressure of the pressure chamber h communicating with the downstream end portion of the faucet or the like via the passage g decreases, and the diaphragm i rises, so that the movement of the diaphragm i causes the upper piston d and the rod to move. It is transmitted to the lower piston f via e. Therefore, the upper piston d and the lower piston f act in the direction of increasing the flow rate by increasing the opening degree of the secondary flow passage and the primary flow passage, respectively.

[Problems to be Solved by the Invention]

However, in the above-mentioned proposal, the flow rate sensing means c provided in the secondary side flow path moves the pistons d and f by the pressure acting on the diaphragm i, and the responsiveness due to pressure fluctuation is good, but the secondary side There is a problem that even if the flow rate changes, the pressure difference for moving the pistons d and f cannot be easily obtained due to this change amount.

Further, as described above, since the flow rate sensing means c provided in the secondary side flow path and the flow rate adjusting means b provided in the primary side flow path are directly connected to each other, the flow rate fluctuation rate of the secondary side fluid is It is directly reflected in the flow rate fluctuation of the primary side fluid. Therefore, when the flow rate fluctuation rate of the secondary side fluid is large, the temperature fluctuation range may become larger than necessary.

Furthermore, since it is difficult to individually set the characteristics of both means b and c according to the conditions, when the conditions relating to the pressure or temperature of each fluid flowing into the primary side and the secondary side change. However, it is not possible to reset the optimum state corresponding to that, and in any case, it is difficult to achieve the intended purpose of always maintaining the secondary side fluid temperature within the desired range.

The present invention has been made to solve the above problems, and the opening degree of the primary side flow path and the opening degree of the secondary side flow path can be controlled separately, and the flow rate of the secondary side fluid can be controlled. It has excellent follow-up characteristics and stability to changes, and it is easy to variably set control characteristics corresponding to changes in conditions such as pressure and temperature, and always maintains the secondary side fluid temperature within the desired range regardless of fluctuations in its flow rate. The present invention is intended to provide a temperature adjusting device for a heat exchanger that can be used.

[Means for Solving the Problems]

According to the present invention, a flow rate adjusting valve 4 is provided in the primary side flow path 2 through which the primary side fluid flows, and the secondary side fluid that exchanges heat with the primary side fluid flows through the heat exchanger 1. A differential pressure adjusting valve 5 is provided in the secondary side flow path 3 located downstream of the heat exchanger, and the flow rate adjusting valve 4 of the primary side flow path 2 is a high pressure divided by a diaphragm 34. With the chamber 35 and the low pressure chamber 36,
A valve body 28 that opens and closes a valve hole 25 formed between the inflow passage 23 and the outflow passage 24 in conjunction with the diaphragm 34 is provided, and the pressure on the upstream side of the heat exchanger in the secondary flow passage and A pressure on the downstream side of the differential pressure adjusting valve 5 is introduced into the high pressure chamber 35 and the low pressure chamber 36, the diaphragm 34 is moved according to the pressure difference between the high pressure chamber and the low pressure chamber, and the valve body 28 causes a valve hole. twenty five
The differential pressure regulating valve 5 of the secondary side flow path 3 includes a high pressure chamber 61 and a low pressure chamber 62 partitioned by a diaphragm 60, and
A valve body 58 that opens and closes a valve hole 55 formed between the inflow passage 53 and the outflow passage 54 in conjunction with the diaphragm 60 is provided.
The pressure on the upstream side of the heat exchanger in the secondary flow path and the pressure on the downstream side of the differential pressure adjusting valve 5 are set to the high pressure chamber 61 and the low pressure chamber 62.
And the diaphragm 60 is moved according to the pressure difference between the high pressure chamber 61 and the low pressure chamber 62, and the opening area of the valve hole 55 is controlled by the valve body 58.

[Operation] Since the present invention is configured as described above, when the flow rate of the secondary flow path changes, the pressure on the upstream side of the heat exchanger 1 in the secondary flow path 3 and the differential pressure regulating valve. A pressure difference is generated between the pressure on the downstream side and the pressure on the downstream side, and the flow rate adjustment valve 4 and the pressure difference adjustment valve 5 can be independently operated by this pressure difference.

In this case, the differential pressure adjusting valve 5 provided in the secondary side flow path 3 is
The pressure on the upstream side of the heat exchanger in the secondary flow path and the pressure on the downstream side of the differential pressure adjusting valve 5 are introduced into the high pressure chamber 61 and the low pressure chamber 62, and the pressure difference between these high pressure chamber 61 and the low pressure chamber 62. Accordingly, the diaphragm 60 is moved to actuate the valve element 58, thereby controlling the opening area of the valve hole 55. Therefore, the secondary side fluid flows through the valve hole 55 of the differential pressure regulating valve 5. At this time,
A pressure loss occurs in the heat exchanger 1 according to the feed water flow rate, and the high pressure chamber 61 and the low pressure chamber 62 of the differential pressure regulating valve 5 have a pressure on the upstream side of the heat exchanger and a downstream side of the differential pressure regulating valve 5. Since the pressure on the side acts, the valve opening corresponding to this pressure difference is maintained. Therefore, the differential pressure adjusting valve 5 acts as a variable orifice, controls the flow rate of the secondary side fluid so as to correspond to the usage amount at the end, and, compared with the case where a fixed orifice is provided, the flow rate for conversion of the pressure difference. Can be expanded, and the pressure detector functions as a pressure detector that transmits this pressure difference to the flow rate adjusting valve 4 of the primary side flow path 2.

As a result, the flow rate adjusting valve 4 installed in the primary side flow path 2 is
The pressure on the upstream side of the heat exchanger in the secondary flow path and the pressure on the downstream side of the differential pressure adjusting valve 5 are introduced into the high pressure chamber 35 and the low pressure chamber 36, and the pressure difference between these high pressure chamber and low pressure chamber The diaphragm 34 is moved to actuate the valve element 28, thereby controlling the opening area of the valve hole 25. Therefore, the flow rate of the primary fluid is controlled.

As a result, the opening degree of the flow rate adjusting valve provided in the primary side flow path can be controlled in relation to the pressure drop in the secondary side flow path. Moreover, since the flow rate control valve of the primary side flow path operates according to the change in the flow rate of the secondary side fluid, that is, the pressure difference, it has excellent responsiveness and good followability without delay in detection. Obtainable.

Further, the flow rate adjusting valve provided in the primary side flow passage operates so as to close the primary side flow passage when there is no pressure difference on the secondary side,
It is possible to prevent leakage when not in use.

Further, each of the flow rate adjusting valve and the differential pressure adjusting valve can be provided with an individual adjusting means, so that when the temperature and pressure load of each of the primary side and the secondary side flowing into the heat exchanger changes. , It is easy to select and adjust each control characteristic individually to the optimum state, and it is possible to extend the adaptive range to the change in conditions.

〔Example〕

The present invention will be described below with reference to an embodiment shown in FIGS. 1 to 3.

In FIG. 1, a heat exchanger 1 includes a primary flow path 2 in which a primary fluid such as a high-temperature heat medium flows and a secondary fluid such as water in which heat is exchanged between the heat medium. The secondary side flow path 3 is provided. A flow rate adjusting valve 4 and a differential pressure adjusting valve 5 configured as described later are connected in series to the primary side flow path 2 and the secondary side flow path 3, respectively.

The secondary flow path 3 is provided with a control flow path 6 including a part of the secondary flow path 3 of the heat exchanger 1 and a differential pressure adjusting valve 5, and a high pressure side end thereof. 7 and the low-pressure side end 8 are connected to the control unit high-pressure chamber connection ends 9 and 10 and the low-pressure chamber connection ends 11 and 12 of the flow rate adjustment valve 4 and the differential pressure adjustment valve 5, respectively. Further, the low-pressure side end portion 8 is connected to an end device 14 such as a faucet through an appropriate pipe 13.

As shown in FIG. 2, the flow rate adjusting valve 4 includes a valve box 20. The valve box 20 is composed of a main body 21 and a lid 22. An inflow passage 23 and an outflow passage 24 for the primary side fluid are formed in the main body 21, and these both flow passages 23 and 24 are connected to a valve hole 25.
Is communicated by. At the periphery of the valve hole 25, the first valve seat 26
Is provided. A first valve body 28, one end of which is opposed to the first valve seat 26 so as to come in contact with and away from the first valve seat 26, is slidably fitted in the tubular portion 27 of the main body 21 in the axial direction. Disc 28
A back pressure chamber 29 is formed on the other end side of the. The first valve body
A through hole 30 is formed in the shaft 28 along the axial direction, and a second valve seat 31 is provided at the peripheral edge of the through hole 30.
A second valve body 32 is opposed to the second valve seat 31 so that the second valve body 32 can come into contact with and separate from the second valve seat 31. When the second valve seat 31 is open, the back pressure chamber 29 passes through the through hole 30 and the outflow passage.
It is designed to communicate with 24.

The control unit 33 is provided with a main diaphragm 34 whose peripheral portion is fluid-tightly sandwiched between the main body 21 and the lid 22, and by the main diaphragm 34, the main diaphragm 34 is provided on the main body 21 side and the lid 22 side. High pressure chamber 35 and low pressure chamber divided respectively
36 are equipped.

The high-pressure chamber 35 is connected via the high-pressure chamber connecting end 9 to the high-pressure side end 7 set in the secondary flow path 3 in FIG. 1, and the low-pressure chamber 36 is connected via the low-pressure chamber connecting end 11. Is connected to the low-pressure side end portion 8 of the secondary side flow path 3.

The main diaphragm 34 is connected to the valve shaft 38 via a pair of support plates 37, 37 that sandwich the main diaphragm 34 from both sides in the thickness direction. The valve shaft 38 is provided integrally with the second valve body 32. ing. Further, a spring member 39 capable of urging the second valve body 32 in the closing direction is provided between the main diaphragm 34 and the lid body 22, and the lid body 22 receives the urging force of the spring member 39. Adjustable means that can be variably set, such as adjusting screw 40, is provided.

The main body 21 is formed with a small chamber 42 partitioned from the high pressure chamber 35 by a cap diaphragm 41, and the small chamber 42 is communicated with the outside through a small hole 43. Further, the valve box 20 is provided with a communication hole 44 that connects the high pressure chamber 35 and the low pressure chamber 36 of the control unit 33. The communication hole 44, in the illustrated example, the main diaphragm 34 and the support plate 37,
It is formed to penetrate 37.

On the other hand, the differential pressure regulating valve 5 is, as shown in FIG.
The valve box 50 has a main body 51 and a lid 52. The main body 51 has a secondary fluid inflow passage 53 and an outflow passage 54.
Are formed, and the inflow passage 53 and the outflow passage 54 are provided with a valve hole 55.
Is communicated by. A valve seat 56 is provided on the peripheral portion of the valve hole 55. Further, a valve body 58, one end of which is opposed to the valve seat 56 so as to come in contact with and away from the valve seat 56, is fitted to the tubular portion 57 of the main body 51 so as to be slidable in the axial direction. The control unit 59 for controlling the opening and closing of the valve body 58 is provided with a diaphragm 60 whose peripheral portion is fluid-tightly sandwiched between the main body 51 and the lid body 52. A high pressure chamber 61 and a low pressure chamber 62, which are partitioned on the lid 52 side, are provided.

The high-pressure chamber 61 is connected via the high-pressure chamber connecting end 10 to the high-pressure side end 7 set in the secondary side flow path 3 of FIG. 1, and the low-pressure chamber 62 is connected to the low-pressure chamber connecting end 12. It is connected to the low-pressure side end portion 8 of the secondary side flow path 3 via.

The diaphragm 60 is connected to a valve shaft 64 via a pair of support plates 63, 63 that sandwich the diaphragm 60 from both sides in the thickness direction, and the valve body 58 is integrally provided on the valve shaft 64. . In addition, the above-mentioned valve body is provided between the diaphragm 60 and the lid 52.
A spring member 65 capable of biasing 58 in the closing direction is provided,
The lid 52 is provided with an adjusting means capable of variably setting the biasing force of the spring member 65, for example, an adjusting screw 66.

The valve box 50 is provided with a communication hole 67 that connects the high pressure chamber 61 and the low pressure chamber 62 of the control unit 59. In the illustrated example, the communication hole 67 is formed by the diaphragm 60 and the support plates 63, 63.
Is formed so as to pass through.

Next, the operation of the device configured as described above will be described.

Since the secondary side fluid does not flow while the end device 14 such as a faucet is closed, the pressure loss in the control flow path 6 is zero, and the fluid pressures at the high and low end portions 7 and 8 are equal. The control pressure difference is zero.

Therefore, in the differential pressure regulating valve 5, the internal pressures of the high-pressure chamber 61 and the low-pressure chamber 62 are equal to each other, so that the valve element 58 has the spring member 65.
Is pressed against the valve seat 56 by the urging force of the valve hole 55, and the valve hole 55 is in the closed state. Similarly, also in the flow rate adjusting valve 4, since the internal pressures of the high pressure chamber 35 and the low pressure chamber 36 are equal to each other, the first valve body 28 and the second valve body 32 cause the first valve seat 26 to move by the urging force of the spring member 39.
Further, the valve hole 25 is closed by being pressed against the second valve seat 31.

The spring members 39 and 65 of the flow rate adjusting valve 4 and the differential pressure adjusting valve 5 are adjusted so that the control pressure and the respective flow rates have a desired relationship by adjusting the adjusting screws 40 and 66, respectively. Optimal states are set corresponding to the temperature and pressure of each fluid on the inflow side of the secondary side flow passage 2 and the secondary side flow passage 3.

When the terminal device 14 such as a faucet is opened, the differential pressure adjustment valve 5
Since the fluid pressure in the control unit low pressure chamber 62 decreases, the diaphragm 60 is displaced toward the low pressure chamber 62 side against the spring member 65, and the valve element 58 is moved in the opening direction via the valve shaft 64. The valve hole 55 is opened from the secondary side fluid, and the secondary side fluid flows through the secondary side flow path 3 of the heat exchanger 1 and the differential pressure regulating valve 5 to the terminal device 14. Then, in a state in which the secondary side fluid flow rate is stable, the differential pressure adjusting valve 5 maintains the pressure loss in the control flow path 6, that is, the opening degree corresponding to the control pressure.

In this case, the differential pressure regulating valve 5 acts as a variable orifice. That is, if the fixed orifice is provided here, the flow rate is proportional to the square of the differential pressure, and therefore the rate of change of the flow rate becomes smaller than the rate of change of the differential pressure, and the control range of the flow rate is restricted. On the other hand, when the variable orifice structure is used, the variation range of the flow rate can be amplified with respect to the variation rate of the differential pressure, and highly accurate control becomes possible.

In this state, the control pressure expanded to the same degree as in the differential pressure adjusting valve 5 also acts between the control unit high pressure chamber 35 and the low pressure chamber 36 of the flow rate adjusting valve 4, so that the main diaphragm 34 moves the spring member 39. The second valve body 32 is moved in the opening direction via the valve shaft 38 by being displaced to the side of the low pressure chamber 36 against. This opens the through hole 30, and the back pressure chamber 29 is opened through this through hole 30.
Is communicated with the outflow passage 24. Therefore, the urging force in the closing direction due to the back pressure is removed from the first valve body 28, and the first valve body 28 is displaced in the opening direction by the primary side fluid pressure on the inflow passage 23 side. Therefore, the valve hole 25 is opened and the flow rate adjusting valve 4 maintains the opening corresponding to the control pressure.

Therefore, the primary fluid flows through the primary passage 2 and the flow rate adjusting valve 4 of the heat exchanger 1.

When the flow rate of the secondary side fluid changes in accordance with the demand amount such as the opening of the faucet changes, the control pressure also changes accordingly. Therefore, each opening of the differential pressure adjusting valve 5 and the flow rate adjusting valve 4 is changed. Also fluctuates according to the control pressure.

Therefore, in this embodiment, the openings of the flow rate adjusting valve 4 and the differential pressure adjusting valve 5 can be automatically controlled by the control pressure corresponding to the pressure loss in the control flow path 6, and in this case, the flow rate is adjusted by the pressure difference. Since the valve 4 and the differential pressure adjusting valve 5 operate, there is no substantial delay in response, and the primary side fluid flow rate is quickly adjusted in response to fluctuations in the secondary side fluid flow rate.
Therefore, the temperature of the secondary fluid can be controlled.

Further, since the flow rate adjusting valve 4 and the differential pressure adjusting valve 5 are provided with the spring members 39 and 65, the adjusting means 40 and 66, etc., not only the setting corresponding to the initial condition can be easily performed as described above. When the temperature, pressure load, etc. of each fluid flowing into the primary-side flow passage and the secondary-side flow passage change, the settings can be individually made to correspond to each.

Further, in the flow rate adjusting valve 4, 1 for the first valve body 28
Since the closed-side flow structure is such that the secondary-side fluid pressure and the secondary-side fluid pressure in the differential pressure regulating valve 5 act on the valve element 58 in the closing direction respectively, it is effective to prevent leakage when not in use. Can be prevented.

Further, in the flow rate adjusting valve 4, two sets of valve bodies 28 and 32 are provided.
Even if such a closed flow structure is provided, it is possible not only to restrain the first valve body 28 in the oil lock state by utilizing the back pressure, but also in the case of a low opening with a small pressure difference. However, since the back pressure is released and the first valve body 28 is operated, reliable control is possible.

Moreover, since the cap diaphragm 41 is provided so as to cause a difference in the effective area on which the control pressure acts, even if the flow of the secondary fluid is stopped and the control pressure becomes zero, the first valve body 28 and the first valve body 28 A pressing force in the closing direction acts on the two-valve element 32, and leakage can be reliably prevented when not in use.

Further, since the flow control valve 4 is provided with the small chamber 42 and the small hole 43, even if the cap diaphragm 41 is damaged due to fatigue or the like, the primary side fluid enters the secondary side flow path. Therefore, it is possible to prevent the secondary side fluid from being contaminated.

Further, since the flow rate adjusting valve 4 and the differential pressure adjusting valve 5 are provided with the communicating holes 44 and 67, respectively, during use, the high pressure chambers 35 and 61 to the low pressure chamber 3 are passed through these communicating holes 44 and 67.
The primary side fluid and the secondary side fluid respectively flow to 6 and 62, and it is possible to prevent the occurrence of decay or the like due to the fluid staying in the control units 33 and 59 for a long time.

The present invention is not limited to the above-described embodiments, but various modifications and applications are possible within the scope of the gist of the invention.

〔The invention's effect〕

As described above, according to the present invention, the flow rate adjusting valve is provided in the primary side flow passage and the differential pressure adjusting valve is provided in the secondary side flow passage,
Since the flow rate control valve and the differential pressure control valve are controlled to open and close in relation to the pressure drop in the secondary fluid, 2
The differential pressure regulating valve in the secondary passage functions as a variable orifice and can be used as a pressure detector of the flow regulating valve in the primary passage. Therefore, the opening degree of the flow rate adjusting valve provided in the primary side flow path can be controlled in relation to the pressure drop in the secondary side flow path. As a result, the change in the flow rate on the secondary side can be immediately responded to the operation of the flow rate adjusting valve of the primary side flow path, and the temperature control due to the change in the flow rate can be favorably followed without a detection delay. .

Further, the flow rate adjusting valve provided in the primary side flow passage operates so as to close the primary side flow passage when there is no pressure difference on the secondary side, and it is possible to prevent the occurrence of leakage when not in use. .

Further, each of the flow rate adjusting valve and the differential pressure adjusting valve can be provided with an individual adjusting means, so that when the temperature and pressure load of each of the primary side and the secondary side flowing into the heat exchanger changes. , It is easy to select and adjust each control characteristic individually to the optimum state, and it is possible to extend the adaptive range to the change in conditions.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, FIG. 2 is a cross-sectional view of a flow rate control valve installed in a primary flow passage, and FIG. 3 is a differential pressure installed in a secondary flow passage. FIG. 4 is a systematic diagram showing a conventional example, and FIG. 5 is a sectional view showing a main part of the conventional example. 1 ... Heat exchanger, 2 ... Primary side flow path, 3 ... Secondary side flow path, 4 ... Flow rate adjusting valve, 5 ... Differential pressure adjusting valve, 6 ... Control flow path, 7 ... … High pressure side end, 8 …… Low pressure side end, 9,10…
… High pressure chamber connection end, 11,12 …… Low pressure chamber connection end, 23 …… Inflow passage, 24 …… Outflow passage, 25 …… Valve hole, 26 …… Valve seat, 28 …… Valve element, 34 …… Diaphragm , 35 …… High pressure chamber,
36 …… Low pressure chamber, 53 …… Inflow passage, 54 …… Outflow passage, 55 …… Valve hole, 56 …… Valve seat, 58 …… Valve body, 60 …… Diaphragm, 61 …… High pressure chamber,
62 …… Low pressure chamber.

Claims (1)

[Claims] 1. A flow rate adjusting valve is provided in a primary side flow path through which a primary side fluid flows, and a secondary side fluid that exchanges heat with the primary side fluid flows through a heat exchanger 2 A differential pressure adjusting valve is provided in the downstream side flow path downstream of the heat exchanger, and the flow rate adjusting valve of the primary side flow path includes a high pressure chamber and a low pressure chamber partitioned by a diaphragm. A valve body that opens and closes a valve hole formed between an inflow path and an outflow path in conjunction with the diaphragm, and has a pressure on the upstream side of the heat exchanger in the secondary flow path and the differential pressure. The pressure on the downstream side of the regulating valve is introduced into the high pressure chamber and the low pressure chamber, and the diaphragm is moved according to the pressure difference between the high pressure chamber and the low pressure chamber to control the opening area of the valve hole by the valve body. The differential pressure regulating valve of the secondary flow path is partitioned by a diaphragm. A high pressure chamber and a low pressure chamber, and a valve body that opens and closes a valve hole formed between the inflow passage and the outflow passage in association with the diaphragm, and the heat exchanger in the secondary flow passage. The pressure on the upstream side and the pressure on the downstream side of the differential pressure regulating valve are introduced into the high pressure chamber and the low pressure chamber, and the diaphragm is moved according to the pressure difference between the high pressure chamber and the low pressure chamber to move the valve element. The temperature adjusting device for a heat exchanger is characterized in that the opening area of the valve hole is controlled by.