JPS6055745B2 - Circulating cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid temperature control system for a cooling device that constantly supplies a stable fluid to a system to be cooled.

2. Description of the Related Art Conventionally, in order to constantly control a system to be cooled to a constant temperature, the temperature of a fluid has been detected and the power supply of a fluid cooling device has been started and stopped.

However, in systems where the cooling system is a closed loop and the fluid capacity in the loop is small, the fluid temperature in the loop rises in a short period of time due to heat load, and conversely, the temperature of the fluid in the loop rises in a short period of time due to the heat load. The frequency of starting and stopping is high.

A compressor for compressing refrigerant is usually used in a cooling device, and the lifespan of the compressor is greatly affected by the interval between startup and shutdown. Generally, this interval is set to 5 minutes or more, and heating the fluid with an electric heater is considered and actually used when the heat load is low, but this method is not recommended due to the risk of electrical leakage, electric shock, or resource saving. So I can't say it's a very good method. Another method is to increase the fluid capacity in the loop, but even in this case, the fluid temperature difference between the inlet and outlet of the heat exchanger is usually 5°C to 10°C for cooling efficiency, and the outlet temperature is still w°C. If the temperature of the fluid supplied to the system to be cooled is about 15 DEG C. and higher than the outlet temperature, the compressor will start and stop frequently unless special fluid control is performed. Figure 1 shows the heat load 1 of the system to be cooled,
A prior art cooling system of a cooling device 2 is shown supplying fluid thereto.

A fluid circulates in a closed loop between the thermal load 1 of the system to be cooled and the cooling device 2. The fluid that has become high temperature due to the heat load 1 returns to the fluid tank 3 and is sent by the fluid delivery device 4 to the heat exchanger 5 in the cooling device. Since the temperature of the fluid cooled by the heat exchanger 5 drops rapidly, only the fluid that leaves the heat exchanger 5 will drop below the control temperature before all the fluids in the loop reach a low temperature. The fluid temperature is detected by a fluid temperature detector 7 provided in front of the heat load 1, and the power to the compressor 6 in the cooling device 2 is stopped.
However, since the fluid in the fluid tank 3 is still at a high temperature, when this high temperature fluid reaches the fluid temperature detector 7, the compressor 6 is activated. In this way, the compressor is frequently started and stopped, and the fluid temperature within the loop fluctuates rapidly, making it impossible to control the fluid temperature within the control temperature range. An object of the present invention is to provide a cooling system that controls starting and stopping of a cooling device when the entire fluid in a closed loop reaches a controlled temperature.

The present invention is characterized in that a cooling device includes a fluid tank for storing fluid returned from a system to be cooled, and a heat exchanger for cooling fluid sent out from the fluid tank. A primary mixing pipe is provided to mix part of the fluid sent out from the heat exchanger and a part of the fluid sent out from the fluid tank, and a second mixing pipe is provided to mix the fluid sent out from the heat exchanger and a part of the fluid in the fluid tank. The next step is to install the mixing piping.

An embodiment of the present invention will be explained in detail with reference to FIG. 2! Ru.

The high temperature fluid returned from the heat load 1 enters the fluid tank 3 and is sent to the heat exchanger 5 by the fluid delivery device 4. A primary mixing pipe 8 is provided as a bypass pipe. In other words, piping is provided to mix the cold fluid coming out of the heat exchanger 5 and the hot return fluid from the heat load 1, and the flow rates of the two fluids are controlled proportionally at the confluence of the two fluids. An automatic valve 9 is provided to detect the fluid temperature with a fluid temperature detector 7 and automatically control the temperature of the fluid sent to the thermal load 1. A secondary mixing pipe 10, which is a bypass pipe, is connected between the fluid outlet side of the heat exchanger 5 and the fluid tank 3.

In other words, a portion of the cooled fluid exiting the heat exchanger 5 and the high temperature fluid from the heat load 1 are mixed within the fluid tank 3. The purpose of this secondary mixing pipe is that when the temperature of the fluid sent to the heat load 1 is decreasing, the amount of high-temperature fluid flowing to the primary mixing pipe 8 gradually increases, so the amount of fluid flowing to the heat exchanger 5 decreases, and the amount of fluid flowing to the compressor 6 decreases. Immediately before the fluid stops flowing, a situation occurs in which no fluid flows at all. This is because a low-temperature refrigerant flows through the heat exchanger 5, and if the flow rate of the fluid that becomes a heat load decreases, the fluid freezes, so it is necessary to keep a constant flow rate flowing. The second purpose of the secondary mixing pipe 10 is to quickly stabilize the fluid temperature in the loop by returning the cooled fluid from the heat exchanger 5 to the fluid tank 3 without passing through the heat load 1. It is meant to be.

In the embodiment shown in Fig. 2, the automatic valve 9 for fluid control is used in the primary mixing pipe 8 section when the heat load 1 is unstable and fluctuates. If it is always safe, the same effect can be obtained by fixing the flow rate through the primary mixing pipe 8 and the flow rate from the heat exchanger 5 using a manual valve so that they flow at a certain constant ratio.

Thus, according to the invention, the temperature of the fluid supplied to the system to be cooled is determined by starting the compressor in the cooling device,
Rapid changes due to stoppage are eliminated, and the fluid temperature in the loop is controlled so that it changes when the entire fluid reaches the control temperature, so the fluid temperature supplied to the cooling system remains stable and the compressor startup and stop times are controlled. This can extend the life of the compressor and improve its reliability as a cooling system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional cooling system, and FIG. 2 is a block diagram of a cooling system showing an embodiment of the present invention. Explanation of symbols, 1...Heat load, 2...Cooling device, 3...Fluid tank, 5...Heat exchanger, 8... ...Primary mixing pipe, 9...Automatic valve, 10...Secondary mixing pipe.

Claims (1)

[Claims] 1 After connecting the system to be cooled and the cooling device with the main piping for fluid circulation, and storing the fluid returned from the system to be cooled in a fluid tank, the fluid sent out from the fluid tank is In a circulating cooling system in which cooling is performed by a heat exchanger installed in the middle of the main piping, and the operation of the heat exchanger is controlled according to the temperature of the cooled fluid, the fluid that has passed through the heat exchanger is In order to mix the fluid sent out from the fluid tank, a primary mixing pipe is provided that branches from the main pipe on the inlet side of the heat exchanger and reaches the main pipe on the outlet side, and a part of the fluid that has passed through the heat exchanger is mixed with the main pipe on the outlet side. A circulating cooling system characterized in that a secondary mixing pipe is provided which branches from the main pipe on the outlet side of the heat exchanger and reaches the fluid tank to mix with the fluid in the fluid tank.