KR20120119140A - Heat pump system utilizing 3 compression cycles - Google Patents

Abstract

PURPOSE: A heat pump system with three compression cycles is provided to easily generate high temperature water used for heating a room as a single cycle heat pump and dual cycle heat pump heat potable water several times. CONSTITUTION: A heat pump system with three compression cycles comprises a single cycle heat pump(100) and a double cycle heat pump(200). The single cycle heat pump comprises a first compressor(1), a first plate type heat exchanger(3), a first expansion valve(5), and a first fin coil heat exchanger(7). The single cycle heat pump firstly heats water. The double cycle heat pump comprises a second compressor(9), a second plate type heat exchanger(11), a second expansion valve(13), a third plate type heat exchanger(15), a third compressor(17), a third expansion valve(19), and a second fin coil heat exchanger(21). The double cycle heat pump secondly heats the water. The heat absorbed by the first fin coil heat exchanger and first compressor is used when the first plate type heat exchanger firstly heats potable water at 50°C~55°C. The heat absorbed by the second fin coil heat exchanger, and the heat from the second and third compressors are used when the second plate type heat exchanger secondly heats the potable water. The hot water at 70°C~90°C for heating a room is generated. [Reference numerals] (AA) High temperature water; (BB) Water

Description

Three-way heat pump system {HEAT PUMP SYSTEM UTILIZING 3 COMPRESSION CYCLES}

The present invention relates to a three-way heat pump system, and more particularly, in a single-stage heat pump composed of a single refrigerant compression cycle, firstly heating the time water to generate hot water (50 ° C. to 55 ° C.), and then The present invention relates to a three-way heat pump system for generating hot water, which can generate hot water (70 ° C. to 90 ° C.) by reheating in a two-way heat pump including a two-stage cycle of a low stage refrigerant compression cycle and a high stage refrigerant compression cycle.

BACKGROUND ART An air heat source heat pump that absorbs heat from outside air with an evaporator of a refrigerant compression cycle and heat-exchanges heat absorbed by a condenser into water is known. The generated hot water is used for hot water supply or for heating.

In order to use the air heat source heat pump as a substitute for an existing boiler that generates hot water for heating or hot water, the air heat source heat pump receives water (usually around 15 ° C) and receives hot water of about 70 ° C to 90 ° C. It should be possible to generate and discharge "hot water"). However, in general, the maximum temperature of hot water that a single stage heat pump using CFC- or HFC-based refrigerants can be produced by receiving water of around 15 ° C is 50 ° C to 55 ° C even when the outside temperature is 7 ° C or more. Do not exceed This limit is due to physical properties such as the boiling point of the refrigerant, the freezing point, the critical temperature, the critical pressure, the heat of evaporation per unit mass, and the compressor discharge gas temperature is excessively increased when the exhaust capacity or capacity of the compressor is matched to the large temperature difference. It is also due to the characteristic that the heating temperature, heating capacity and grade coefficient are rapidly lowered.

Hot water or heating heat pumps are mainly used in winter. In the case of the heat pump, when the air heat source is used as the heat source, a decrease in the coefficient of performance due to the decrease in the outside temperature is inevitable. As the evaporator is implanted, the amount of air passing through the coil decreases, and the heat transfer to the refrigerant is blocked, thereby lowering the heat absorption capacity and evaporation capacity of the refrigerant, and consequently the heating capacity in the condenser. Efficiency is also drastically reduced. In general, in the heat pump, an electric heater is installed to compensate for such a problem. Since the grade coefficient is 1, the heat pump offsets the advantages of the heat pump.

In order to generate hot water while using CFC- or HFC-based refrigerants, a number of binary heat pump systems or binary refrigeration cycles are disclosed which combine two refrigeration cycles in one heat exchanger.

Korean Patent No. 10-0639104 discloses a heat pump system for cooling and heating and hot water using a dual refrigeration cycle having a cascade heat exchanger, and Korean Patent No. 10-0690090 discloses a cascade heat pump system using seawater as a heat source. In addition, Korean Patent No. 10-0974271 discloses a heat pump system using a binary compression method, Korean Patent No. 10-0815727 discloses a drying system using a binary heat pump, and Korean Patent No. 10-0531653 describes an auxiliary heat. A dual heat pump system is disclosed in which a heat source of a pump system is heat exchanged with a heating medium of a main cycle system in an auxiliary heat exchanger. Although these two-way heat pump systems show that a combination of two-way refrigeration cycles can reach operating ranges that cannot be output by conventional single-stage cycles, these two-level heat pump systems have reached a level that makes them practical to produce hot water at 70 ° C to 90 ° C. I can't.

However, when the outside air temperature falls in winter, especially when the outside air temperature falls below -6.7 ° C, the coefficient of performance (COP) of the heat pump falls below two. In other words, the amount of heat absorbed from the outside air falls below the level of heat supplied from the compressor. Moreover, in winter, when the outside air temperature falls below 4.5 ° C, frost is generated around the evaporator, which further prevents the absorption of heat from the air. Therefore, when the outside air temperature falls below zero in winter, even when using a binary heat pump system, it is more difficult to generate hot water of 70 ° C to 90 ° C.

In order to produce hot water of 70 ℃ ~ 90 ℃ as a heat pump, a carbon dioxide heat pump system using carbon dioxide (CO ₂ ) refrigerant has been developed and spread, but if the system adopts the air heat source method, the outside air temperature is below- When the temperature falls below 6.7 ° C, it is difficult to generate high temperature water of 70 ° C to 90 ° C because the decrease in the coefficient of performance is caused by the reduction of evaporation heat.

However, the heat pump is certainly economical than using an electric heater having a grade coefficient of 1 because the grade coefficient can be maintained at 1.5 to 3.5 depending on the outside temperature even in winter.

The present invention was made to solve the problem of generating hot water using a winter heat pump, and the first problem to be solved by the present invention can be used for hot water supply or heating regardless of the outdoor air temperature during the winter while utilizing the energy saving effect of the heat pump. To provide a three-way heat pump system capable of producing hot water of 70 ℃ ~ 90 ℃.

The second problem to be solved by the present invention is to provide a three-way heat pump system that can also be used as a single stage heat pump or binary heat pump according to the outside temperature.

The above object of the present invention is a first compressor for compressing a first refrigerant at high temperature and high pressure, a first plate heat exchanger in which the first refrigerant discharged from the first compressor releases heat to condense and water, and the first plate type. It is composed of a first expansion valve in which the first refrigerant condensed in the heat exchanger expands to low pressure, and a first fin coil heat exchanger in which the first refrigerant expanded to low pressure in the first expansion valve absorbs heat from air and evaporates water. A single stage heat pump for primary heating; And a second plate heat exchanger for compressing the second refrigerant at high temperature and high pressure, and a second plate heat exchange in which the second refrigerant discharged from the second compressor discharges heat to water introduced from the first plate heat exchanger of the single stage heat pump. For example, the second expansion valve in which the second refrigerant condensed in the second plate heat exchanger expands to low pressure, the second refrigerant expanded to low pressure in the second expansion valve exchange heat with the third refrigerant, and the second refrigerant evaporates. The third refrigerant includes a third plate heat exchanger condensing, a third compressor compressing the third refrigerant at high temperature and high pressure, and injecting the third plate heat exchanger into the third plate heat exchanger, and expanding the third refrigerant condensed in the third plate heat exchanger to low pressure. And a second expansion valve configured to include a second fin coil heat exchanger configured to absorb the amount of heat from the air and evaporate the third refrigerant expanded at low pressure in the third expansion valve. One Heat Pump Sheath To be settled by.

According to the present invention having the above-described configuration, the first and second heat exchangers in the first plate heat exchanger of the single stage heat pump are heat-treated at 50 ° C. to 55 ° C. by the heat absorbed by the first fin coil heat exchanger and the heat applied by the first compressor. Thereafter, the first heated time water is secondarily heated in the second plate heat exchanger of the binary heat pump by the heat absorbed by the second fin coil heat exchanger, the heat applied by the third compressor, and the heat applied by the second compressor. By the heat pump can be easily obtained hot water of 70 ℃ ~ 90 ℃ can be used for hot water supply or heating, there is an effect that can be used as a single-stage heat pump or binary heat pump according to the outside temperature in one system.

1 is a block diagram of an embodiment of a three-way heat pump system according to the present invention.
2 is a block diagram of another embodiment of a three-way heat pump system according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the three-way heat pump system according to the present invention.

Although not shown in the drawings, the three-way heat pump system according to the present invention is well-known programmable logic for controlling the components (such as the compressor, the solenoid valve, the water temperature sensor, the outside temperature sensor, and the like) described below. It includes a controller (PLC), a microcomputer employing controller (MCU) or a microprocessor and a controller employing a peripheral device thereof, and a control program executed in these controllers.

As shown in FIG. 1, the three-way heat pump system according to the present invention organically combines a single stage heat pump 100 and a binary heat pump 200 to generate hot water. . The single stage bottom pump 100 and the binary heat pump 200 are connected to the water pipe WP in the first plate heat exchanger 3 and the second plate heat exchanger 11 in which the refrigerant circulating each cycle is condensed. Is connected. The single stage heat pump 100 receives the water of about 15 ° C. and heats it first to make hot water of 50 ° C. to 55 ° C., and the binary heat pump 200 is primarily heated in the single stage heat pump 100. The water is heated second to hot water at 70 ° C to 90 ° C.

The single stage heat pump 100 includes a first compressor 1 for compressing a first refrigerant at high temperature and high pressure, and a first plate type in which the first refrigerant discharged from the first compressor 1 discharges heat to water and condenses it. A heat exchanger (3), a first expansion valve (5) in which the first refrigerant condensed in the first plate heat exchanger (3) expands at a low pressure, and a first expansion valve at a low pressure in the first expansion valve (5) One refrigerant consists of a first fincoil heat exchanger 7 which absorbs heat from the air and evaporates. R12 or R114 may be used as the first refrigerant.

The binary heat pump 200 includes a second compressor 9 for compressing the second refrigerant at a high temperature and high pressure, and a second plate discharged from the second compressor 9 is the first plate type of the single stage heat pump 100. The second plate heat exchanger 11 for releasing and condensing heat quantity into water introduced from the heat exchanger 3 and the second expansion valve for expanding the second refrigerant condensed in the second plate heat exchanger 11 to low pressure. (13), and a third plate heat exchanger (15) in which the second refrigerant expanded at a low pressure in the second expansion valve (13) exchanges heat with the third refrigerant, and the second refrigerant is evaporated and the third refrigerant is condensed. The third compressor 17 for compressing the third refrigerant at a high temperature and high pressure to be introduced into the third plate heat exchanger 15 and the third refrigerant condensed in the third plate heat exchanger 15 to expand at low pressure. A third expansion valve 19 and a second fin coil heat exchanger in which the third refrigerant expanded at low pressure in the third expansion valve 19 absorbs heat from the air and evaporates it; 21), the water flowing from the first plate heat exchanger (3) of the single stage heat pump (100) is heated second to the second plate heat exchanger (11) to form hot water of 70 ° C to 90 ° C.

At this time, the second refrigerant compression cycle of the two refrigerant compression cycles constituting the binary heat pump 200, the second refrigerant is the second compressor (9)-> second plate type heat exchanger (11)-> second expansion valve (13)-> Third plate heat exchanger (15)-> Second compressor (9) is circulated. In addition, the third refrigerant compression cycle of the two refrigerant compression cycles constituting the binary heat pump 200, the third refrigerant is the third compressor (17)-> third plate heat exchanger (15)-> third expansion valve ( 19)-> The second fin coil heat exchanger (21)-> The third compressor (17) is circulated. In this process, the second fin coil heat exchanger 21 absorbs the heat of outside air and releases it to the third plate heat exchanger together with the heat applied from the third compressor. Absorbed in the evaporation process of the second refrigerant. In this process, the third plate heat exchanger 15 performs heat exchange between the second refrigerant and the third refrigerant, wherein the third refrigerant is condensed and supercooled, and the second refrigerant is evaporated and superheated. In the third plate heat exchanger (15), the second refrigerant received heat from the third refrigerant is evaporated, and the second refrigerant gas evaporated is sucked into the second compressor (9) and then compressed. The second refrigerant gas is to heat the water with hot water while removing the superheat, completely condensing and subcooling the second plate heat exchanger (11).

The present invention uses the first plate heat exchanger 3 of the single stage heat pump 100 as the primary heater of water, and the output refrigerant is used as the second refrigerant in the second plate heat exchanger 11 of the binary heat pump 200. By exchanging heat with water, the water temperature which can be produced | generated only by the single stage heat pump 100 is exceeded.

The second and third refrigerants may use a combination of R12 and R22 or a combination of R12 and R114, respectively. In the binary heat pump 200 of the present invention, the ratio of the refrigerant discharge amount between the third compressor 17 and the second compressor 9 may be different. In general, the larger the difference between the evaporation temperature and the condensation temperature is, the greater the third refrigerant discharge amount is, which is advantageous for efficiency, and the smaller the temperature difference, the lower the third refrigerant discharge amount is preferably designed. This is because the third refrigerant can absorb more heat from the outside air and transfer it to the second refrigerant.

2 shows another embodiment of the present invention. As described below, according to another embodiment of the present invention, various operations are possible according to the water exit temperature and the outside air temperature. Although not shown in the drawings, the present invention includes an outside air temperature sensor for measuring the outside air temperature, and each component is controlled by the controller.

As shown in FIG. 2, a temperature sensor 23 is further provided at a high temperature water output end of the second plate heat exchanger 11, and an output value of the temperature sensor 23 is equal to or less than a predetermined temperature (for example, 70 ° C.). Only in this case, the third compressor 17 can be controlled to operate the third refrigerant cycle. This is because, in a season such as spring or autumn, when the outside air temperature rises to 7 ° C. or more, hot water can be obtained only by the first refrigerant cycle and the second refrigerant cycle without using the third refrigerant cycle of the binary cycle 200.

In addition, as shown in Figure 2, the hot water output terminal of the first plate heat exchanger (3) after branching the water pipe (WP) is provided with a first solenoid valve 25 in the branched water pipe, the second plate heat exchange The second solenoid valve 27 is also provided at the high temperature water output stage of the machine 11, and when the output of the high temperature water is unnecessary, such as in summer, the operation of the binary heat pump 200 is stopped, and the second solenoid valve ( 27 may be closed and the first solenoid valve 25 may be opened to use only hot water generated by the single stage heat pump 100. In addition, when the outside air temperature is lowered and it is difficult to generate hot water at 50 ° C. to 60 ° C. only by the single stage heat pump 100, the operation of the single stage heat pump 100 may be stopped and only the dual heat pump 200 may be operated. .

By doing so, the three-way heat pump system according to the present invention can be used as a single stage heat pump or binary heat pump according to the outside temperature.

1: first compressor 3: first plate heat exchanger
5: first expansion valve 7: first fin coil heat exchanger
9: second compressor 11: second plate heat exchanger
13: 2nd expansion valve 15: 3rd plate type heat exchanger
17: third compressor 19: third expansion valve
21: second fin coil heat exchanger 23: water temperature sensor
25, 26: solenoid valve 100: single stage heat pump
200: binary heat pump WP: water pipe
CP: refrigerant tube

Claims (3)

A first compressor for compressing the first refrigerant at high temperature and high pressure, a first plate heat exchanger in which the first refrigerant discharged from the first compressor discharges heat to condense, and a first refrigerant condensed in the first plate heat exchanger A first expansion valve configured to expand at a low pressure, and a first fin coil heat exchanger configured to absorb a quantity of heat from air and evaporate the first refrigerant expanded at a low pressure from the first expansion valve; And
A second compressor for compressing the second refrigerant at a high temperature and high pressure, and a second plate heat exchanger in which the second refrigerant discharged from the second compressor discharges heat to the water introduced from the first plate heat exchanger of the single stage heat pump. And a second expansion valve in which the second refrigerant condensed in the second plate heat exchanger expands at a low pressure, and a second refrigerant expanded at a low pressure in the second expansion valve exchanges heat with the third refrigerant to evaporate the second refrigerant. The third refrigerant is a third plate heat exchanger that condenses, the third compressor compresses the third refrigerant at high temperature and high pressure, and enters the third plate heat exchanger to expand the third refrigerant condensed in the third plate heat exchanger to low pressure. A third expansion valve and a second heat pump configured to heat the secondary water by a second fin coil heat exchanger configured to absorb the amount of heat from the air by evaporation of the third refrigerant at a low pressure from the third expansion valve; Heat pump system.
The method of claim 1,
A water temperature sensor 23 is further provided at the water output end of the second plate heat exchanger 11, and the third compressor 17 is operated only when the output value of the water temperature sensor 23 is equal to or lower than a predetermined temperature. Three-way heat pump system characterized by.
The method of claim 1,
At the water output end of the first plate heat exchanger (3), after branching the water pipe (WP), a first solenoid valve (25) is provided at the branched water pipe, and a second water output end of the second plate heat exchanger (11) is also provided. When the solenoid valve 27 is provided and the output of the high temperature water is not necessary, the operation of the binary heat pump 200 is stopped, the second solenoid valve 27 is closed and the first solenoid valve 25 is opened. The three-way heat pump system, characterized in that to use only hot water generated in the single-stage heat pump (100).

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