JPH0613945B2 - Expansion valve for refrigeration equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an expansion valve for use in a refrigeration system to control the amount of refrigerant supplied to an evaporator.

(Prior Art) An expansion valve for a refrigeration system, which has a role of adjusting the amount of refrigerant supplied to the evaporator of the refrigeration system in response to changes in heat load, is a temperature-operated type that operates in response to changes in the refrigerant temperature. It is known to operate in response to fluctuations in the refrigerant vapor pressure and keep the vapor pressure inside the evaporator constant, or to use a float type. Among them, the temperature-operated expansion valve is a relatively wide temperature range. Since it works sensitively over the range, it exerts sufficient capacity, especially in the period until the refrigeration system enters a stable operating state. However, because the space to be cooled or the object is lacking in the ability to control the refrigerant supply after it has been cooled to the desired temperature, the refrigerant temperature downstream of the evaporator is too low, and it is necessary to install an evaporation pressure adjustment valve etc. downstream of it. was there. The other constant pressure expansion valve does not have the ability to control the refrigerant supply amount according to the temperature change, but it has the function of keeping the refrigerant vapor pressure in the evaporator constant, so that the temperature-operated expansion valve as described above is used. It was characterized in that it could overcome the drawbacks of.

(Problems to be Solved by the Invention) However, as described in the section of the prior art, an expansion valve having both functions is not known. Therefore, the present invention has advantages of both a temperature-operated expansion valve that performs a satisfactory function during a transitional period such as when the refrigerator is started, and a constant pressure expansion valve that keeps the vapor pressure in the evaporator constant when fluctuations in the refrigeration load are small. It is an object of the present invention to provide an expansion valve for a refrigerating machine having only

(Means for Solving the Problems) Therefore, the present invention relates to a pressure responsive member that is displaced according to the pressure of the gas enclosed in the temperature sensing cylinder that detects the outlet refrigerant temperature of the evaporator of the refrigeration system, and the displacement of the pressure responsive member. An expansion valve for a refrigeration system, which has a spring member biased in a direction opposite to the direction, and is configured to maintain an appropriate valve opening degree according to a force received from the spring member and the pressure responsive member, A gas adsorbent is incorporated in the temperature sensitive cylinder, and the enclosed gas is
A technical means of using an expansion valve for a refrigerating apparatus, which is composed of a mixed gas of two or more kinds having different adsorption rates to the gas adsorbent, is adopted.

(Operation) Explaining the operation by the above technical means, the expansion valve for a refrigerating device of the present invention has a gas adsorbent in the temperature sensing cylinder for detecting the outlet refrigerant temperature of the evaporator, and an adsorption system for the gas adsorbent. By enclosing two or more different mixed gases, the temperature changes greatly while the refrigerant temperature or vapor pressure in the evaporator is high for a while after the refrigerator starts operating, so it is enclosed in the temperature-sensitive cylinder. Among the mixed gas, the partial pressure of the gas that has a high adsorption rate to the gas adsorbent plays the role of a temperature actuated expansion valve because the pressure fluctuation in the temperature sensing cylinder becomes dominant, and is transmitted from the temperature sensing cylinder. Performs a precise valve opening / closing action based on the variation information of the refrigerant temperature at the evaporator outlet.

When the heat load on the evaporator decreases and the refrigerant temperature drops below a certain level, the gas adsorbent's adsorption capacity reaches saturation due to the gas with the highest adsorption rate among the enclosed gases, so the gas pressure in the temperature sensing cylinder is The pressure reduction due to adsorption disappears, and the function as a temperature-operated expansion valve is lost.

However, since the partial pressure of the gas having a slow adsorption rate remaining in the temperature-sensitive cylinder is maintained, the pressure in the temperature-sensitive cylinder becomes constant, and the function as a constant pressure expansion valve occurs.

Therefore, the expansion valve for a refrigerating apparatus of the present invention has an excellent effect that the opening degree of the valve can be always kept in an appropriate state from the transitional period when the fluctuation of the refrigerating load is large to the steady state when the refrigerating load is constant.

(Example) An expansion valve for a refrigerating apparatus of the present invention will be described below based on an example shown in the accompanying drawings.

In FIG. 1 as a side sectional view of the expansion valve of the present invention, 1
Is a vibrating body, 2 is a refrigerant inlet port, 3 is a refrigerant outlet port, 5 is an orifice, 6 is a ball valve, 7 is a valve body, 8 is a pressure spring of a spring member, 9 is a spring retainer, and 10 is an evaporator outlet. A temperature sensitive tube for detecting the temperature of the refrigerant, 11 is a diaphragm, and 12 is activated carbon used as a gas adsorbent and is incorporated in the temperature sensitive tube. Reference numeral 13 is an operating rod for transmitting the movement of the diaphragm 11 to the valve body 7,
Reference numeral 14 is a member for mounting the operating rod 13, 15 and 16 are upper and lower diaphragm chambers, 17 is an upper constituent member of the diaphragm chamber, and 18 is a change in the refrigerant temperature at the outlet of the evaporator as a fluctuation of the gas pressure in the upper diaphragm chamber. A capillary tube serving as a communication passage for the gas sealed in the temperature-sensitive cylinder 10 for transmission to 15, a pipe communicating with the evaporator 19 and a wire net 20 for preventing the activated carbon 12 in the temperature-sensitive cylinder 10 from flowing out.

Further, the upper diaphragm chamber 15 of the expansion valve and the in-cylinder space inside the temperature-sensitive cylinder 10 are communicated with each other through the chaperilar tube 18, and the adsorbing capacity of activated carbon is saturated in these communicating spaces at -13 ° C. As described above, freon gas having a high adsorption rate to activated carbon is adsorbed, and subsequently nitrogen gas having a very low adsorption rate to activated carbon is sealed so as to have a pressure of 1.0 kg / cm ² . If the enclosed gas is a combination of Freon and air, the gas will consist primarily of a mixture of the three. The combination of the mixed gas is not limited to the above-mentioned combination, and a combination having different adsorption rates for the gas adsorbent can be used.

As the gas adsorbent of the present invention, in addition to activated carbon, synthetic zeolite, molecular jive or the like can be used.

Further, in the operation system diagram of the refrigerant device shown in FIG.
30 is a compressor, 31 is a condenser for cooling and liquefying high-temperature and high-pressure refrigerant vapor, 32 is a cooling fan for the condenser 31, 33 is a receiver for liquefied refrigerant, 34 is an expansion valve according to the present invention, 35 is an evaporator for liquefied refrigerant evaporation, Reference numeral 36 is a blower for blowing air as an object to be cooled to the evaporator 35, and reference numeral 10 is a temperature sensitive tube for transmitting a change in the refrigerant temperature at the outlet of the evaporator 35 to the expansion valve 34.

Next, regarding the operation of the expansion valve of the present invention, as a graph showing the relationship between the refrigerant temperature sensed by the temperature sensing cylinder 10 and the pressure exerted on the upper surface of the diaphragm 11 to which the operating rod 13 of the valve body is attached. The following is a description with reference to FIG.
The evaporator 35 is operated for a while after the start of the operation of the refrigeration system.
The heat load exerted on is large and it is necessary to replenish the refrigerant sufficiently. At this time, the temperature of the refrigerant sensed by the temperature sensing cylinder 10 is high, and the gas enclosed in the cylinder is less adsorbed to the activated carbon 12 and is expanded, and the gas pressure is expanded through the capillary tube 18 into the upper diaphragm chamber 15 of the expansion valve 34. This force is transmitted to the diaphragm 11 and pushes down the operating rod 13 attached to this diaphragm, so in the end, a ball valve attached to the tip surface of the operating rod 13 in proportion to the degree of increase of the refrigerant temperature. The gap between the valve 6 and the valve seat widens, and the amount of refrigerant flowing into the evaporator 35 increases.

If the evaporator 35 sufficiently promotes the cooling work and the heat load is reduced by continuing the operation of the refrigerating apparatus, the refrigerant supply will have a margin. Therefore, the temperature sensitive tube 10 senses at the outlet of the evaporator 35. The refrigerant temperature gradually decreases, and the freon gas is adsorbed by the activated carbon. When the expansion valve 34 reaches -13 ° C., the freon gas in the enclosed mixed gas is adsorbed by the activated carbon 12 and the adsorption is saturated, so that the diaphragm is saturated. Only nitrogen gas exerts pressure on 11 and the function as the temperature-operated expansion valve is lost.

Therefore, when the refrigerant temperature is −13 ° C. or lower, the pressure drop due to the adsorption of the enclosed gas is eliminated, and the nitrogen gas keeps the pressure in the upper diaphragm chamber 15 constant, so that the diaphragm 11 is kept stable.
Moves up and down on the basis of fluctuations in the upper and lower gas pressures of the diaphragm, and starts to exert a function as a so-called constant pressure expansion valve that adjusts the gap between the ball valve 6 and the valve seat via the operating rod 13. . In this embodiment, the operating pressure of the pressure spring 8 for closing the valve body is set to 0.5 kg / cm ² , and nitrogen gas is -1 at the upper part of the diaphragm 11.
Since the expansion valve 34 is sealed so as to have a pressure of 1.0 kg / cm ² at 3 ° C., the expansion valve 34 is closed when the gas pressure in the evaporator 35 located downstream of the valve is reduced to 0.5 kg / cm ² or less, that is, When the sum of this gas pressure and the operating pressure of the pressure spring 8 of 0.5 kg / cm ² is less than 1.0 kg / cm ² , that is, when the pressure is less than the point a in FIG. It always plays a role of preventing the refrigerant vapor pressure in the evaporator 35 from dropping to 0.5 kg / cm ² or less. If it exceeds 0.5 kg / cm ² , the valve will be closed again.

(Effects of the Invention) As described above, in the present invention, a gas adsorbent and a mixed gas of two or more kinds having different adsorption rates to the gas adsorbent are provided in the temperature sensing cylinder for detecting the outlet refrigerant temperature of the evaporator. Both of the temperature-operated expansion valve that performs a satisfactory function during the transition period such as the start-up of the refrigerator by enclosing it and the pressure increase valve that keeps the vapor pressure in the evaporator constant when the refrigeration load fluctuation is small It is possible to provide an expansion valve for a refrigeration system having only advantages.

[Brief description of drawings]

1 is a side sectional view of an expansion valve for a refrigerating apparatus according to the present invention, FIG. 2 is a correlation graph between a refrigerant temperature downstream of an evaporator and a gas pressure exerted on an upper surface of a pressure responsive member, and FIG. 3 is a refrigerating apparatus. It is an operation system diagram. In the figure, 1 ... Valve body, 2, 3 ... Refrigerant inlet and outlet ports, 6 ... Ball valve, 7 ... Valve body, 8 ... Pressure spring, 10 ... Temperature sensing tube, 11 ... Diaphragm, 12 ... Activated carbon, 13 ... Actuating rod, 17 ... Upper component of diaphragm chamber, 18 ... Capillary tube, 20 ... Wire mesh, 30 ... Compressor, 34 ... Expansion valve, 35 ... Evaporator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 54-15345 (JP, U) Rikai 59-25149 (JP, U) Japanese Patent Sho 47-10148 (JP, B2) Japanese Public Sho 50- 1104 (JP, B2)

Claims (1)

[Claims] Claim: What is claimed is: 1. A pressure responsive member that is displaced in accordance with a pressure of a gas enclosed in a temperature sensing cylinder that detects a temperature of an outlet refrigerant of an evaporator of a refrigerating device, and is urged in a direction opposite to a displacement direction of the pressure responsive member. An expansion valve for a refrigerating apparatus, which has a spring member and is configured to maintain an appropriate valve opening degree according to a force received from the spring member and the pressure responsive member, wherein a gas adsorbent is incorporated in the temperature sensing cylinder. Then, the enclosed gas is
An expansion valve for a refrigerating apparatus, comprising a mixed gas of two or more kinds having different adsorption rates to the gas adsorbent.