JP-7856224-B1 - Ejector-type cooling system

Abstract

The ejector-type cooling system 10A comprises a condenser 18, a refrigerant pump 12, a steam generator 14, an evaporator 20, an ejector 16, and an intermediate heat exchanger 24. The system includes a drive pressure sensor 41 for detecting the drive pressure of the drive flow, a drive temperature sensor 42 for detecting the drive temperature of the drive flow, and a control unit 50A that calculates the drive saturation temperature based on the drive pressure and performs feedback control to reduce or stop the rotation speed of the refrigerant pump 12 when the drive superheat, which is the difference between the drive temperature and the drive saturation temperature, falls below a preset reference value.

Inventors

• 松原 健
• 安嶋 賢哲
• 森 泰二

Assignees

• 富士電機株式会社

Dates

Publication Date

20260511

Application Date

20250321

Claims (2)

1. A condenser that condenses a gaseous refrigerant by exchanging heat with a heat-dissipating water, A refrigerant pump that pressurizes and circulates the refrigerant condensed in the condenser, A steam generator to which the refrigerant discharged from the aforementioned refrigerant pump is supplied and which exchanges heat with hot water to evaporate it, Hot water is connected to the steam generator so as to flow in series downstream, and a refrigerant is supplied from a branch between the condenser and the refrigerant pump via an expansion valve to evaporate the hot water through heat exchange. An ejector is connected such that the refrigerant evaporated in the steam generator is supplied as a driving flow to the driving flow port, thereby drawing in the refrigerant supplied from the evaporator as a suction flow from the suction port, and supplying these refrigerants to the condenser from the discharge port, An ejector-type cooling system comprising an intermediate heat exchanger that cools hot water by exchanging heat with the heat-dissipating water between the steam generator and the evaporator, which are connected in series, A drive pressure sensor for detecting the drive pressure of the drive flow, A drive temperature sensor for detecting the drive temperature of the drive flow, A control unit calculates the drive saturation temperature based on the drive pressure, and performs feedback control to reduce or stop the rotation speed of the refrigerant pump when the drive superheating degree, which is the difference between the drive temperature and the drive saturation temperature, falls below a preset reference value . A hot water input temperature sensor for detecting the hot water input temperature of the hot water supplied to the steam generator, Equipped with, The ejector-type cooling system is characterized in that the control unit calculates an estimated hot water input temperature based on the time change of the hot water input temperature detected by the hot water input temperature sensor, and if the subtracted value obtained by subtracting the drive saturation temperature from the estimated hot water input temperature is less than a preset value, it reduces or stops the rotation speed of the refrigerant pump, while if the subtracted value is equal to or greater than the preset value, it performs feedforward control to maintain the rotation speed of the refrigerant pump .
2. A condenser that condenses a gaseous refrigerant by exchanging heat with a heat-dissipating water, A refrigerant pump that pressurizes and circulates the refrigerant condensed in the condenser, A steam generator to which the refrigerant discharged from the aforementioned refrigerant pump is supplied and which exchanges heat with hot water to evaporate it, Hot water is connected to the steam generator so as to flow in series downstream, and a refrigerant is supplied from a branch between the condenser and the refrigerant pump via an expansion valve to evaporate the hot water through heat exchange. An ejector is connected such that the refrigerant evaporated in the steam generator is supplied as a driving flow to the driving flow port, thereby drawing in the refrigerant supplied from the evaporator as a suction flow from the suction port, and supplying these refrigerants to the condenser from the discharge port, An ejector-type cooling system comprising an intermediate heat exchanger that cools hot water by exchanging heat with the heat-dissipating water between the steam generator and the evaporator, which are connected in series, A drive pressure sensor for detecting the drive pressure of the drive flow, A drive temperature sensor for detecting the drive temperature of the drive flow, A control unit calculates the drive saturation temperature based on the drive pressure, and performs feedback control to reduce or stop the rotation speed of the refrigerant pump when the drive superheating degree, which is the difference between the drive temperature and the drive saturation temperature, falls below a preset reference value . A flow control valve is provided on the heat dissipation water inlet side of the intermediate heat exchanger and adjusts the flow rate of the heat dissipation water, A hot water outlet temperature sensor is provided on the hot water outlet side of the evaporator and detects the hot water outlet temperature of the hot water. Equipped with, The ejector-type cooling system is characterized in that the control unit controls the opening and closing of the flow rate control valve so that the added temperature, obtained by adding a predetermined value to the hot water outlet temperature detected by the hot water outlet temperature sensor, approaches the target hot water intermediate temperature, which is a target value on the hot water outlet side of the intermediate heat exchanger, and controls the opening degree of the expansion valve so that the hot water outlet temperature detected by the hot water outlet temperature sensor approaches the target hot water outlet temperature, which is a target value on the hot water outlet side of the evaporator .

Description

This invention relates to an ejector-type cooling device. Conventionally, an ejector-type cooling system is known, as proposed in Patent Document 1. In this ejector-type cooling system, an ejector is provided between a steam generator (which serves as a refrigerant heating means) and a condenser in the circulation path through which the refrigerant is circulated. The refrigerant discharged from the steam generator is supplied to the ejector as a driving fluid, while the refrigerant discharged from the ejector is supplied to the condenser. A branch path is provided in the section of the circulation path located between the condenser and the refrigerant pump. The branch path is equipped with an expansion valve and an evaporator, and supplies the refrigerant after passing through the evaporator as a suction fluid to the ejector. In this ejector-type cooling system, if a heat source such as hot water is supplied to the steam generator and radiant water is supplied to the evaporator, it is possible to obtain chilled water cooled in the evaporator. Japanese Patent Publication No. 2022-144290 Figure 1 is a block diagram showing the configuration of a production system to which an ejector-type cooling device, an embodiment of the present invention, is applied.Figure 2 is a circuit diagram showing the configuration of an ejector-type cooling device according to Embodiment 1 of the present invention.Figure 3 is a flowchart showing the superheating control process procedure by the control unit shown in Figure 2.Figure 4 is a circuit diagram showing the configuration of an ejector-type cooling device according to Embodiment 2 of the present invention.Figure 5 is a flowchart showing the control processing procedure by the control unit shown in Figure 4.Figure 6 is a circuit diagram showing the configuration of an ejector-type cooling device according to Embodiment 3 of the present invention.Figure 7 is a flowchart showing the control processing procedure by the flow control valve opening/closing processing unit of the control unit shown in Figure 6.Figure 8 is a flowchart showing the control processing procedure by the expansion valve opening adjustment processing unit of the control unit shown in Figure 6. A preferred embodiment of the ejector-type cooling device according to the present invention will be described in detail below with reference to the attached drawings. <Embodiment 1> Figure 1 is a block diagram showing the configuration of a production system to which an ejector-type cooling device, an embodiment of the present invention, is applied. The production system illustrated here involves connecting an ejector-type cooling device 10, which utilizes an ejector, to a production device 11 such as an aluminum die-casting machine. The ejector-type cooling device 10 cools the hot water W1 discharged from the production device 11, which has reached a high temperature of, for example, about 60°C, to, for example, hot water W2 of about 25°C, and returns it to the production device 11. The production device 11 then uses the cooled hot water W2 for its cooling process during production. In other words, this production system creates a circulation system for hot water W1, where the ejector-type cooling device 10 cools the cooled hot water used by the production device 11 for its cooling process and returns it to the production device 11 again as cooling water. The target to which the ejector-type cooling device 10 is connected is not limited to the production equipment 11. The source supplying hot water W1 to the ejector-type cooling device 10 and the destination supplying hot water W2 may be different. Figure 2 is a circuit diagram showing the configuration of an ejector-type cooling device according to Embodiment 1 of the present invention. The ejector-type cooling device 10A illustrated here comprises a refrigerant pump 12, a steam generator 14, an ejector 16, a condenser 18, an evaporator 20, an expansion valve 22, a drive pressure sensor 41, a drive temperature sensor 42, a hot water input temperature sensor 43, and a control unit 50A. The refrigerant pump 12 pressurizes the liquid phase refrigerant and circulates it within the circuit. The steam generator 14 receives the refrigerant discharged from the refrigerant pump 12 and evaporates it by exchanging heat with the hot water W1. The ejector 16 receives the refrigerant evaporated in the steam generator 14 through the drive port 16a and supplies it to the condenser 18. The condenser 18 condenses the gaseous refrigerant supplied from the ejector 16 by exchanging heat with the radiating water. This radiating water is supplied via the branching section B2 of the flow path L3 in the cooling water circuit. The radiating water supplied from the flow path L3 is mainly industrial water or water supplied from a circulating cooling tower. The radiating water that has exchanged heat with the refrigerant in the condenser 18 is discharged from the flow path L4. The refrigerant