KR100531113B1 - Tow-stage Compression Heat Pump Using Controllable Intermediate Heat Exchanger - Google Patents

Abstract

The present invention relates to a two-stage compressed cold and hot manufacturing system manufactured to perform cooling and heating in one system, a single stage compression operation in the summer, a two-stage compression operation in the winter season, the system having an optimal intermediate pressure A system comprising a separate intermediate cooler for control and a high stage compressor protection device through liquid level control in a flash tank, wherein the flash tank (17) and the intermediate cooler (16) are separated and disposed. 17 is provided with a water level detection sensor 18, which is a sensor for detecting the level of the refrigerant, and an alarm sensor 181 informing the flash tank 17 that the refrigerant is saturated, and the pressure of the refrigerant flowing into the evaporator 118. Evaporator pressure sensor 121 for telling the measurement and the condenser pressure sensor 120 for measuring and indicating the pressure of the refrigerant flowing out of the condenser 14 is provided, the sensors A flash tank level controller 112 is provided to control the level of the intermediate pressure and the flash tank in response to a signal, and receives a signal from the alarm sensor 181 to immediately send refrigerant from the low stage compressor 11 to the high stage compressor 13. It relates to a two-stage compression cold and hot manufacturing system having a bypass valve controller 19 for controlling the bypass valve 110 to be made.

Description

Two-stage Compression Cold / Heat Manufacturing System with Separate Intermediate Cooler {Tow-stage Compression Heat Pump Using Controllable Intermediate Heat Exchanger}

The present invention relates to a two-stage compressed cold and hot manufacturing system manufactured to perform cooling and heating in one system, a single stage compression operation in the summer, a two-stage compression operation in the winter, and to have an optimal intermediate pressure A system comprising a separate intermediate cooler for control and a high stage compressor protection through liquid level control in a flash tank.

Where a single system is capable of heating and cooling, existing products are either air conditioners (or chillers) and heaters in one package, or heat pump type air conditioners using only one compressor.

However, when the air conditioner (or chiller) and the heater are placed in one package like the former, the energy consumption for heating heat is excessively high, and even the heat pump type air conditioner that saves energy like the latter is winter When the temperature of the heat source decreases during operation, the operation efficiency of the compressor decreases due to the excessive compression ratio along with the evaporation pressure decrease, and the system efficiency decreases due to the decrease in the heating capacity due to the decrease in the system circulation flow rate. In addition, if the evaporation pressure is lowered, the compressor discharge port refrigerant temperature may be excessively increased, which may adversely affect the safety of the system.

Accordingly, the present invention is designed to solve the above problems, even if the temperature of the heat source during the winter operation is lowered, it is not operated at an excessive compression ratio to prevent a reduction in the operating efficiency of the compressor, and at the same time prevents a reduction in the system circulation flow rate heating capacity It is aimed at preventing the degradation of the system efficiency by maintaining. In addition, even if the evaporation pressure is lowered, there is also an object to prevent the excessive rise of the compressor discharge refrigerant temperature to promote the safety of the system.

In the present invention in order to achieve the above object in the two-stage compressed cold and hot manufacturing system manufactured to perform the cooling and heating in one system, the single stage compressed cooling operation for the stable operation of the system in the summer, In winter, two stages of compression heating operation was performed for high efficiency operation, and a separate intermediate cooler for easy system control to have an optimum intermediate pressure and a high stage compressor protection device through liquid level control in a flash tank were provided.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a two-stage compression cold and hot manufacturing system to which a separate intermediate cooler according to the present invention is applied.

In the summer operation mode, after the cold water 123 is manufactured, the refrigerant compressed by the low stage compressor 11 through the accumulator 119 is introduced into the condenser 14 through the three-way side 12. The refrigerant condensed by exchanging heat with the heat sink 124 collects in the receiver 15, passes through the three-way valve 126, expands through the main refrigerant line expansion valve 117, and flows into the evaporator 118 to be cooled again. 123 is prepared.

In the winter operation mode, the refrigerant absorbed heat from the heat source water 122, passed through the accumulator 119, and the refrigerant compressed by the low stage compressor 11 flows into the flash tank 17 through the three-way side 12. At the same time, a portion of the high pressure liquid refrigerant passing through the condenser 14, the receiver 15, and the three-way side 126 passes through the secondary refrigerant line expansion side 113, and then the intermediate cooling flow rate control side 1 115 and the separate type. It enters the flash tank 17 through the intermediate cooler 16 and the intermediate cooling flow rate control valve 2 116. Next, the saturated gas collected in the upper portion of the flash tank 17 is compressed again in the high stage compressor 13, passes through the condenser 14 to produce the hot water 125, and then collects in the receiver 15. Pass 126 through the secondary refrigerant line flow control valve 114 and the separate intermediate cooler (16). Next, it expands while passing through the main refrigerant line expansion valve 117 and flows into the evaporator 118 to absorb heat from the heat source water 122.

In the process as described above, the intermediate pressure and flash tank level controller 112 is installed to obtain the best system operating efficiency for any high pressure and low pressure. In order to obtain the optimum intermediate pressure, the input signal of the intermediate pressure and flash tank level controller 112 is an output signal of the high pressure signal converter 120, an output signal of the low pressure signal converter 121, and an output signal of the water level detector 18. With respect to the above three input signals, the intermediate pressure and the flash tank level controller 112 may use the secondary refrigerant line expansion valve 113 and the secondary refrigerant line flow control valve to obtain the optimum intermediate pressure within the range of maintaining the safety level in the flash tank. 114), the opening degree of the intermediate cooling flow rate control valve 1 (115) and the intermediate cooling flow rate control valve 2 (116) is controlled.

In addition, the bypass valve controller 19 can protect the high stage compressor 13 even if an operation condition exceeding a control range may occur or if the entire system is unstable due to a system problem outside the controller. ) Was installed. The input signal of the bypass valve controller 19 is the output signal of the alarm sensor 181, and when the output signal is "off", the bypass valve controller 19 closes the bypass valve 110 and the safety valve 111 ) To allow the system to operate normally. If the output signal of the water level detection unit 181 is "on", the bypass valve controller 19 opens the bypass valve 110 and closes the safety valve 111 so that liquid refrigerant flows into the high stage compressor 13. Prevents the system from becoming unsafe.

As described above, the present invention can perform cooling and heating in one system, and in the case of winter operation, due to the control operation of the intermediate pressure and the flash tank level controller 112 and the bypass valve controller 19, Since the system is always operated to have an optimum intermediate pressure, the high stage operation of the low stage compressor 11 and the high stage compressor 13 is always maintained in a high efficiency operation state, and through the separate intermediate cooler 16 to the main refrigerant line expansion valve 117. Since the coolant liquid can be sufficiently cooled, the reduction in the heating capacity is much smaller than that of the conventional single stage compressor applied heat pump heating system even when the temperature of the heat source water 122 decreases. In addition, since the high stage compressor 13 sucks only the saturated gaseous refrigerant after heat exchange in the separate intermediate cooler 16 and the flash tank 17, the outlet temperature of the high stage compressor 13 is higher than that of the conventional single stage compressor. It is significantly lower than the compressor outlet refrigerant temperature of the system, and therefore has very good characteristics in terms of safety of the system.

1: Schematic diagram of a two-stage compressed cold and hot manufacturing system applying a separate intermediate cooler according to the present invention

*** Explanation of symbols for main parts of drawing ***

 11: 1st (low) stage compressor

 12, 126: 3-way valve

 13: 2nd (high stage compressor)

 14 condenser

 15: liquid reservoir

 16: Intermediate Heat Exchanger

 17: flash tank

 18: liquid level sensor

 19: by-pass valve controller

 110: by-pass valve

 111: safety valve

 112: intermediate pressure and flash tank liquid level controller

 113: liquid sub-stream expansion valve

 114: liquid sub-stream control valve

 115: intermediate heat exchange control valve 1

 116: intermediate heat exchange control valve 2

 117: liquid main-stream expansion valve

 118 evaporator

 119: accumulator

 120: high pressure transducer

 121: low pressure transducer

 122: heat source for winter season in winter operation mode

 123: chilled water for summer season

 124: Heat sink for summer season

 125: hot water for winter season produced in winter operation mode

 181: liquid level alarm sensor

Claims (3)

Cold and hot heat system equipped with an intermediate cooler (16) for maximizing the cooling effect by increasing the supercooling rate of the refrigerant sent to the flash tank (17) and the evaporator. As a manufacturing system, the single stage compressed cooling operation using only the low stage compressor 11 is performed in the summer for the stable operation of the system, and the two stage compressed heating using both the low stage compressor 11 and the high stage compressor 13 for the high efficiency operation in winter. In the cold and hot compression system to operate, The flash tank 17 and the intermediate cooler 16 are separated and disposed, and the level detection sensor 18 and the flash tank 17, which are sensors for detecting the level of the refrigerant in the flash tank 17, are notified that the refrigerant is saturated. Is provided with an alarm sensor 181, the condenser pressure sensor for measuring the pressure of the refrigerant flowing out of the evaporator pressure sensor 121 and the condenser 14 to inform by measuring the pressure of the refrigerant flowing into the evaporator 118 120 is provided, the flash tank level controller 112 for controlling the intermediate pressure and the level of the flash tank in response to the signals of the sensor is provided, and receives the signal of the alarm sensor 181 in the low stage compressor (11) A two-stage compression cold and hot manufacturing system with a bypass valve controller 19 for controlling the bypass valve 110 to send the refrigerant directly to the high stage compressor (13). The method of claim 1, The intermediate pressure and the flash tank level controller 112 are designed to obtain an optimal intermediate pressure that can achieve the best system operating efficiency within the range of maintaining the safety level in the flash tank 17 for any high pressure and low pressure during winter operation. Receiving the output signal of the condenser pressure sensor 120, the output signal of the evaporator pressure sensor 121 and the output signal of the flash tank level detection sensor 18 as an input signal, the secondary refrigerant line expansion valve 113, the secondary refrigerant line flow rate adjustment A two-stage compression cold and hot manufacturing system that controls the opening degree of the side (114), the intermediate cooling flow rate control side 1 (115) and the intermediate cooling flow rate control side 2 (116) to ensure operation at optimum efficiency conditions at all times. The method of claim 1, In order to prevent the liquid refrigerant from flowing into the high stage compressor 13 even when the operating condition exceeds the control range during winter operation or the entire system is unstable due to a system problem outside the controller, an alarm sensor as an input signal. In response to the output signal of 181, when the output signal is "off", close the bypass valve 110 and open the safety valve 111 to allow the system to operate normally, the output signal of the alarm sensor 181 Is “on”, the bypass valve controller 19 opens the bypass valve 110 and closes the safety valve 111 to perform a control operation to protect the high stage compressor 13. .