JPH0434695B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) A method and apparatus for measuring the heat radiation amount of a heat exchanger according to the present invention is applicable to a heat exchanger used as a radiator or a heater core for cooling water heat radiation of a water-cooled engine. It can be used to measure the amount of heat dissipation.

(Background of the Invention) A heat exchanger having a structure as shown in FIG. 1 is widely used, for example, as a radiator for dissipating heat from cooling water in a water-cooled engine. This heat exchanger has seat plates 4 and
Tanks 5a and 5b are provided via 4. When dissipating heat from cooling water, the cooling water is sent through the inlet pipe 6 provided in the upper tank 5a,
If the cooling water is sent out from the outlet pipe 7 provided in the lower tank 5b, the core part 3 will flow down from the upper tank 5a to the lower tank 5b through the liquid passage pipes 1, 1. Heat is exchanged with the air flowing in the front and back directions, and the heat is radiated and the temperature decreases.

Incidentally, in order to know the performance of a heat exchanger configured and operated in this manner, or to determine the amount of water flow and air blown for the most efficient use, the amount of heat released from the heat exchanger may be measured. To perform such heat radiation measurement, a wind tunnel 8 is used as shown in Figure 2.
The core part 3 of the heat exchanger is
Hot water is flowed into the heat exchanger while blowing air to the core, and the amount of heat released is determined from the amount of hot water and the amount of hot water before and after passing through the core. If the amount of hot water is G (Kg/hr), the temperature of the hot water before passing through the core is T ₁ (℃), and the temperature of the hot water after passing through the core is T ₂ (℃), then the amount of heat dissipation Q (K
cal/hr) is calculated using the following formula. However, in the following formula, C (K cal/Kg·℃) is the specific heat of water.

Q=C・G(T ₁ −T ₂ ) By the way, when measuring the amount of heat released from a heat exchanger as described above, conventionally it is accurate to use a thermometer for detecting water temperature to show an accurate measurement value. This was an absolute condition for making accurate measurements. However, the precision of thermometers used to measure heat radiation is not usually that high, and an error of about 0.1°C is inevitable. On the other hand, the difference between the hot water T ₁ and T ₂ before and after passing through the core section is not so large, and when the amount of water passing through is large, the temperature is often only about 1 to 2 degrees Celsius. If the difference between hot water before and after passing becomes small, even if the reading on the thermometer deviates by just 0.1°C from the true hot water, the error in the measured value of heat radiation will be about 5 to 10%, and accurate radiation will not be possible. The amount of heat is no longer required.

(Object of the invention) In order to solve the above-mentioned disadvantages, the present invention
A method for measuring the amount of heat released from a heat exchanger that allows accurate measurement of the amount of heat released without the error of the thermometer directly affecting the measured value of the amount of heat released, and equipment directly used to implement the method. The purpose is to provide the following.

(Structure of the Invention) The method of measuring the amount of heat released from the heat exchanger of the present invention is to first send hot water from one tank, discharge it from the other tank, radiate heat from this hot water, and then install the heat exchanger on the side of the one tank. The difference between the temperature of the hot water before heat radiation detected by the first thermometer and the temperature of the hot water after heat radiation detected by the second thermometer installed on the other tank side,
and the first measured value Q ₁ is determined from the amount of hot water sent in. Next, hot water of the same temperature and volume is sent from the other tank that was previously on the discharge side, and is discharged from one tank that was previously on the feed side,
The second measured value is determined from the difference between the temperature of the hot water before heat radiation detected by the second thermometer and the temperature of the hot water after heat radiation detected by the first thermometer, and the amount of hot water sent in.
Find Q ₂ .

If there is no error in the first and second thermometers, the first and second measured values Q ₁ and Q ₂ will both match the true amount of heat dissipation Q (Q ₁ = Q ₂ = Q), but Even if there is an error in either thermometer, each measured value Q ₁ ,
Q ₂ differs from the true amount of heat dissipation Q (Q ₁ ≠ Q ₂
≠Q).

Therefore, in the case of the method of the present invention, the first,
By adding the second measured values Q ₁ and Q ₂ , the error of each thermometer is canceled out, and the sum of the above heat radiation amounts (Q ₁ + Q ₂ )
Find the true amount of heat dissipation Q by halving.

That is, the temperature of hot water on the high temperature side before heat radiation is T ₁ and the temperature of hot water on the low temperature side after heat radiation is T ₂ . If there are errors (positive or negative), the first and second measured values Q ₁ and Q ₂ are calculated using the following equations.

Q ₁ = C・G {(T ₁ + α) − (T ₂ + β)} Q ₂ = C・G {(T ₁ + β) − (T ₂ + α)} Adding these two measured values Q ₁ and Q ₂ , Q ₁ + Q ₂ = C・G (2T ₁ − 2T ₂ ) = 2Q Therefore, by adding these first and second measured values Q ₁ and Q ₂ and halving them, the error of either thermometer can be The true amount of heat dissipation Q can be determined without being affected by the

Next, the measuring device for carrying out the above-described method is constructed as shown in the embodiments shown in FIGS. 3 and 4, and FIG. The figures each show a state in which the second amount of heat radiation is measured. An end of a hot water pipe 10 for feeding hot water at a constant temperature is connected via a first three-way valve 11 to a first hose 12 whose one end is connected to the inlet pipe 6 of the upper tank 5a. Further, one end of the hot water discharge pipe 13 for discharging the hot water whose temperature has been lowered by the heat radiated by the heat exchanger is connected to the outlet pipe 7 of the lower tank 5b via the second three-way valve 14. It leads to the second hose 15. A first bypass pipe 16 connected at one end to the first three-way valve 11
The other end is connected to the discharge pipe 13 between the second three-way valve 14 and the outlet pipe 7, and the second three-way valve 14
The other end of the second bypass pipe 17 is connected to the water supply pipe 10 between the first three-way valve 11 and the inlet pipe 6 .

When measuring the amount of heat released from the heat exchanger using the measuring device configured as described above, first, the two three-way valves 11 and 14 are switched to the state shown in FIG. 3, and the first measured value Q ₁ is obtained. Next, both three-way valves 11 and 14 are switched to the state shown in FIG. 4, and a second measured value _Q2 is obtained. Three-way valve 1 to determine the first measured value Q ₁
1 and 14 to the state shown in FIG. 3, hot water sent from the hot water pipe 10 is transferred to the first hose 12
The hot water is fed into the upper tank 5a through the inlet pipe 6, and the hot water at the temperature _T1 in the tank 5a further decreases in temperature to T2 while passing through the core part ₃ , and enters the lower tank 5b. The hot water sent into the lower tank 5b further passes through the outlet pipe 7 and the hose 15, and is discharged from the discharge pipe 13. The temperature T ₁ of the hot water before heat radiation is measured by a first thermometer (not shown; it has an error α) inserted into the part through which the hot water passes before passing through the core, such as the inlet pipe 6. The temperature T ₂ is measured by a second thermometer (not shown, has an error β) inserted into the outlet pipe 7, etc., where the hot water passes after passing through the core, and the measured value T ₁ + α is calculated. , T ₂ +β is obtained. As described above, the first measured value Q ₁ is calculated from the measured values T ₁ +α, T ₂ +β and the hot water flow rate G.

Next, the first to find the second measured value Q ₂ ,
When the second three-way valves 11 and 14 are switched to the state shown in FIG. and enters the lower tank 5b. Temperature T ₁ inside this lower tank 5b
While passing through the core section 3, the temperature of the hot water drops to _T2 , enters the upper tank 5a, and is further discharged from the discharge pipe 13 through the inlet pipe 6, hose 12, and second bypass pipe 17. At this time, the temperature T ₁ of the hot water before heat radiation is measured by the second thermometer inserted into the outlet pipe 7, contrary to the case of obtaining the first measured value Q ₁ shown in FIG. T ₁ +β is obtained,
The temperature T ₂ after heat dissipation is measured by a first thermometer inserted into the inlet pipe 6 to obtain a measured value T ₂ +α. Calculate the second measured value Q ₂ from the measured values T ₁ + β and T ₂ + α, and further calculate half of the sum Q ₁ + Q ₂ with the first measured value Q ₁ as the true amount of heat dissipation Q. is as described above.

(Effects of the Invention) As described above, the method and device for measuring the amount of heat released from a heat exchanger according to the present invention can accurately measure the amount of heat released with simple work without using particularly expensive measuring equipment. .

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of a heat exchanger whose heat radiation amount is measured by the method and apparatus of the present invention, FIG. Figures 3 and 4 are approximately vertical sectional side views each showing a state in which the amount of heat radiation is measured by the measuring device of the present invention. 1: Liquid pipe, 2: Fin, 3: Core part, 4: Seat plate, 5a, 5b: Tank, 6: Inlet pipe, 7: Outlet pipe, 8: Wind tunnel, 9: Fan, 10: Hot water pipe, 1
1, 14: Three-way valve, 12, 15: Hose, 13:
Discharge pipe, 16, 17: Bypass pipe.

Claims (1)

[Scope of Claims] 1. A method for measuring the amount of heat released from a heat exchanger comprising tanks provided at both ends of a core portion consisting of a large number of liquid flow pipes and fins, wherein The temperature T ₁ of the hot water is measured by a first thermometer, and the temperature T ₂ of the hot water after heat radiation that has passed through the core and sent into the other tank is measured by a second thermometer. The first measurement value Q ₁ of the amount of heat dissipation is determined from the temperature of the hot water and the flow rate of the hot water, and then the temperature T ₁ of the hot water before heat dissipation sent into the other tank is measured with a second thermometer, and the core part is measured. Temperature of hot water after heat dissipation passed through and sent into one tank T ₂
is measured by the first thermometer, and the second measured value of the amount of heat radiation is determined by the temperature of the hot water before and after the heat radiation and the flow rate of the hot water.
A method of measuring the amount of heat released from a heat exchanger by determining Q ₂ and determining half of the sum of the first and second measured values Q ₁ and Q ₂ as the amount of heat released. 2. Both ends of the core section consisting of a large number of liquid passage pipes and fins are connected to an inlet side tank 5a and an outlet side tank 5b.
This is a device for measuring the amount of heat released from a heat exchanger connected to
A first thermometer is connected to the outlet pipe 7 of the outlet tank, and a second thermometer is provided to measure the temperature inside the outlet tank. A first three-way valve 11 is provided in the hot water pipe 10, a second three-way valve 14 is provided in the discharge pipe 13, and the first three-way valve 11 is connected to the hot water pipe 10 by switching these. A first bypass pipe 16 that communicates with the discharge pipe 13 is connected between the second three-way valve 14 and the outlet pipe 7, and the second three-way valve 14 is connected to the discharge pipe 13 by switching this. This device measures the amount of heat released from a heat exchanger in which a second bypass pipe 17 connected to a hot water pipe 10 is connected between a three-way valve 11 and an inlet pipe 6.