WO2013016883A1 - Flow-changing cyclic heat pump water heater - Google Patents

Abstract

Disclosed in the present invention is a flow-changing cyclic heat pump water heater, which comprises a refrigerant loop system, a evaporator intake system, a condenser water side flow-changing automatic cyclic loop system and an electric control system. A water inlet pipeline (2) of the condenser water side flow-changing automatic cyclic loop system is provided with a flow rate automatic regulating valve or automatic regulating bypass vale (10). Or a circulating water pump which is arranged on the water inlet pipeline of the condenser is arranged as a variable flow pump (3). The flow rate automatic regulating valve or automatic regulating bypass vale (10) or the circulating water pump (3) is connected with the electric control system through a circuit. The average water temperature at the condenser water side (a heated side) and the temperature of the outlet water of the condenser is controlled though an inlet water changing method of the condenser of the heat pump water heater so that the heat pump system works relatively steadily, the condensing efficiency of the condenser(6) is improved, and the working pressure of the compressor (5)is reduced, thereby prolonging the service life of the compressor(5), reducing the power consumption and improving the thermal coefficient of performance(COP).

Description

 Variable flow circulating heat pump water heater

[Technical Field] The present invention relates to the field of water heater technology, and more particularly to a variable flow circulating heat pump water heater. [Background Art] It is said that heat pump water heaters have gradually become popular as a new energy technology, and gradually replace the traditional electric heating heat books.

Water. Developed countries have included electric water heaters as banned products, replaced by solar water heaters or heat pump water heaters. Heat pump water heater due to its working characteristics for heating water, (1 water temperature changes throughout the year; 2 water temperature change during heating; 3 heat pump operation efficiency change in winter and summer) heat pump water heater system condenser water side (heated side) temperature instability The condenser fluorine side (heating side) is unstable, the compressor load changes, the temperature rises and overheats, the compressor working pressure rises, and the condensing saturation temperature point rises, so that the heat conversion efficiency (COP) decreases. The efficiency indicated on the nameplate of the manufacturer's heat pump water heater is the result of the operation under the ideal working condition of the laboratory, and the actual operating efficiency is at least 30% of the marked value. The national standard stipulates that the COP of the circulating heat pump water heater shall not be lower than 3.7 (C0P^3. 7), and the actual operation value shall not be less than 90% of the marked value. Actually, the operation is generally very high under the efficiency of C0P=2.5. Well, the test of the heat pump water heater sold in the market shows that the operating efficiency C0P=1. 7 has, the water temperature rises and the COP decreases, and the compressor overheating affects the service life, which makes the popular application of the heat pump water heater seriously affected, and the consumers spend more common. The heat pump water heater bought by the water heater 2-3 times is not as energy-saving as the manufacturer advertised. How to stabilize the heat pump efficiency at the test level? How can the fundamental improvement of the unstable state of the heat pump water heater be improved? How can the compressor be operated under relatively stable conditions? This is critical for heat pump water heaters.

[Summary of the Invention] The object of the present invention is to solve the above-mentioned deficiencies and provide a variable flow circulating heat pump water heater. The condenser inlet water flow rate change method of the heat pump water heater system controls the average water temperature of the condenser water side (heated side), and controls the condenser water outlet temperature to make the heat pump system work relatively stable, enhances the condenser condensation efficiency, and reduces compressor operation. The pressure, which extends the life of the compressor and reduces power consumption, increases the heat transfer efficiency (C0P). In order to achieve the above object, a variable flow circulating heat pump water heater is designed, which comprises a refrigerant circuit system, an evaporator air inlet system, a condenser water side variable flow automatic circulation loop system and a circuit control system, wherein the refrigerant circuit system includes a pipeline A closed flow path composed of a compressor, a condenser, an expansion valve and an evaporator is sequentially connected, and the evaporator air inlet system includes an air inlet and outlet guide device and a wind inlet and outlet power device, and the condenser water side variable flow automatic circulation The loop system includes a condenser, a water storage tank and a circulating water pump connected in sequence through a pipeline, and the condenser water inlet conduit of the condenser water side variable flow automatic circulation loop system is provided with a flow automatic regulating valve or a flow automatic adjusting bypass valve Or the circulating water pump on the condenser inlet pipe adopts a variable flow pump, and the flow automatic regulating valve or the flow automatic adjusting bypass valve or the variable flow pump controls the system through the circuit connecting circuit. The circuit control system includes a main controller, a human machine interface, a signal sensor, and a combined component. The signal sensor comprises a temperature sensor and a pressure sensor, wherein the temperature and pressure sensors are respectively installed in an air inlet of the evaporator, in the water storage tank, on the refrigerant circuit system pipeline, and on the water side of the condenser water flow automatic circulation loop system. On the road. The working principle of the invention:

= l ^{x V} , ^XX temperature rise, ¥ = heated water input work J 860 X meter power consumption

C = specific heat of water, = density of water); 2. Output heat = · Q · C · (Q = flow rate (L/min liter / min), Δί = condenser outlet water temperature Τ 6 - condenser inlet water temperature Τ 5, = water specific heat lkcal / kg · K, = Water density);

 3. The invention changes the inlet flow rate of the condenser by recognizing the change of the water temperature, so that the outlet water temperature of the condenser satisfies the national standard (GB23137-2008, the outlet water temperature is 55°0 and is not too high. For example: multiple circulation heat pump water heater condenser The inlet water temperature starts at 20 °C. Under the constant flow rate, a cycle temperature rise (At=15 °C) is assumed, and the water temperature rises to 35 °C (At=15 °C) at the end of the first cycle, the second cycle (At=15 °C), water inlet 35°C, water output 50°C, water temperature 55°〇 according to national standard GB23137-2008, third cycle must be carried out, third cycle water inlet 50°C (At=15° C), the effluent is 65 ° C, the result of the third cycle leads to a decrease in COP. (The third cycle causes the COP to fall: the effluent is 65 ° C, the condensation saturation temperature is usually 65 V, and the saturation temperature is 65 ° C. Taking the refrigerant 134a as an example The saturation pressure is 18.9bar, the pressure rises, and the work results in a decrease in efficiency. The pressure rises to work and the conversion to thermal energy efficiency does not exceed 1, that is, C0P 1. Therefore, operating at over temperature causes the COP to drop.

Compared with the prior art, the invention has the advantages that: the invention adopts a method for recognizing the temperature change flow, and effectively avoids the instability of the condenser refrigerant over temperature operation, for example, whether the inlet water temperature is 20 ° C, and the temperature is recognized by the temperature. The inlet water is 20 °C. According to the programmed procedure, the first circulating water temperature can be adjusted to 45 °C by adjusting the flow method. During the operation, the flow rate can be corrected continuously by detecting the change of the water temperature, so that the outlet water temperature is basically Constant at 45 ° C, then when entering the second cycle, through the above method, the outlet water temperature is controlled between 55 ° C ~ 57 ° C, completely avoid the water temperature rise above 65 ° C, the condenser refrigerant overheating The temperature of the condensation saturation point is controlled at 55 ° C, 10 ° C lower than 65 ° C, the pressure corresponding to the saturation point temperature of 55 ° C is 14. 9 bar ( 134a), the specific saturation temperature is 65 ° C The saturation pressure P=18. 9bar (134a) is 4bar lower, which improves the operating efficiency of the system and prevents the compressor from overheating. In the same way, the primary heating heat pump water heater will cause unstable operating conditions and low operating efficiency due to seasonal changes in water temperature and efficiency. The flow change is determined by the program preset by the circuit control system. The method drives a variable flow pump or a flow automatic regulating valve or a flow automatic regulating bypass valve to change the flow rate, so that the heat pump operates in an optimally stable and high COP state. The program design basis for variable flow: First, in order to improve the COP (the heat pump is operated to make the average temperature of the condenser water side (heated side) as low as possible to ensure that the system operates under high efficiency conditions); Meet the specified temperature of 55 ° C, and not too high, the condensing saturation temperature and saturation pressure are effectively controlled, protect the compressor and increase the COP, select the best mode of operation according to changes in ambient temperature and inlet water temperature: one-time heating or Multiple cycles of heating. The invention runs through the test, and the variable flow method is adopted in the same system to increase the COP by 10% to 13% than that of the method without changing the flow rate, and the effect is very remarkable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the structure of a variable flow pump according to the present invention; FIG. 2 is a schematic view showing the structure of an automatic flow regulating valve according to the present invention; 4 is a schematic structural view of a second method for automatically adjusting a bypass valve according to the present invention; FIG. 5 is a schematic diagram of the working principle of the present invention; wherein: 1 is a water storage tank, 2 is a condenser water inlet pipe, 3 is a variable flow pump, 4 is the expansion valve, 5 is the compressor, 6 is the condenser, 7 is the evaporator, 8 is the condenser outlet pipe, 9 is the water to be heated, 10 is the flow automatic adjustment valve or the flow automatic adjustment bypass valve, 11 is Water pump, 12 inlet and outlet wind power unit (axial flow fan), T1 is water tank water temperature sensor, T2 is ambient temperature sensor, T3 is compressor inlet temperature sensor, T4 compressor outlet refrigerant temperature sensor, T5 is condenser inlet water temperature sensor, T6 is the condenser outlet water temperature sensor, P1 is the low pressure sensor, and P2 is the high pressure sensor.

[detailed description] The present invention will be further described below with reference to the accompanying drawings. As shown in FIG. 1, the present invention includes a refrigerant circuit system, an evaporator air inlet system, a condenser water side variable flow automatic circulation loop system, and a circuit control system. The reagent loop system comprises a closed flow path comprising a compressor 5, a condenser 6, an expansion valve 4 and an evaporator 7 through a pipeline, the evaporator inlet air system comprising a wind inlet and outlet guide and an air inlet and outlet power The device (axial flow fan) 12; the condenser water side variable flow automatic circulation loop system includes a condenser 6 connected to the condenser, a water storage tank 1 and a variable flow pump 3, and the variable flow pump 3 is installed in the condenser On the water inlet pipe 2, the variable flow pump controls the system through a circuit connection circuit. The circuit control system comprises a main controller, a human machine interface, a signal sensor and a combined component; the signal sensor comprises a water tank water temperature sensor Tl, an ambient temperature sensor Τ2, a compressor inlet temperature sensor Τ3, a compressor outlet refrigerant temperature sensor Τ4 The condenser inlet water temperature sensor Τ5, the condenser outlet water temperature sensor Τ6, the low pressure sensor PI and the high pressure sensor P2; the water tank water temperature sensor Π is installed in the water storage tank 1, and the ambient temperature sensor T2 is installed in the evaporator At the wind, the compressor inlet temperature sensor T3 and the compressor outlet refrigerant temperature sensor Τ4 are installed on the refrigerant circuit system line, and the condenser inlet water temperature sensor Τ5 and the condenser outlet water temperature sensor Τ6 are installed in the condenser water. On the pipeline of the side variable flow automatic circulation loop system, the low pressure sensor P1 and the high pressure sensor Ρ2 are respectively installed at the inlet and the outlet of the compressor. As shown in Figures 2, 3 and 4, the other embodiments of the present invention differ from the embodiment shown in Figure 1 only in that: the variable flow pump 3 becomes the existing constant flow circulating water pump 11, The condenser inlet pipe of the condenser water side variable flow automatic circulation loop system is provided with a flow automatic regulating valve or a flow automatic regulating bypass valve 10, and the flow automatic regulating valve or the flow automatic adjusting bypass valve 10 is connected through the circuit Control System. This technical solution can also achieve the object of the present invention. The gist of the present invention is that the heat pump water heater system realizes the control of the average water temperature of the water side (heated side) of the condenser by changing the flow rate of the water side of the condenser, and the water temperature of the water side (heated side) of the condenser Degree, make the heat pump system condenser fluorine side (heating side) saturation point temperature and pressure relatively stable. Change the heat pump water heater system due to changes in water temperature, ambient temperature changes, the flow side of the condenser water flow is unchanged, and the operating conditions are unstable. See Figure 5 for the variable flow principle of the water side (heated side) of the condenser of the heat pump water heater. Changes in efficiency due to seasonal changes, changes in inlet water temperature, or heating during operation (water tank temperature is increasing) cause changes in condenser inlet water temperature (sensor T5) and condenser outlet water temperature (sensor Τ6). The flow control condenser outlet water temperature (sensor Τ6) is used to control the change of the compressor outlet refrigerant temperature (sensor Τ4), thereby stabilizing the compressor operating conditions and effectively increasing the COP. To achieve the adjustment of the condenser inlet water flow, there are mature technologies that can be utilized. (For example: 1 pressure regulating variable flow pump 2 variable frequency variable flow pump 3 flow automatic regulating valve 4 bypass adjustment, etc., can achieve the purpose of linear adjustment of water flow.) The present invention is not limited by the above embodiments, any other Changes, modifications, substitutions, combinations, and simplifications that are made without departing from the spirit and scope of the invention are intended to be equivalents and are included in the scope of the invention.

Claims

Claim  A variable-flow circulating heat pump water heater comprising a refrigerant circuit system, an evaporator air inlet system, a condenser water-side variable-flow automatic circulation loop system, and a circuit control system, wherein the refrigerant circuit system includes a pipeline through a closed flow path comprising a compressor, a condenser, an expansion valve and an evaporator, the evaporator air inlet system comprising an air inlet and outlet guide and a wind inlet and outlet power device, the condenser water side variable flow automatic circulation circuit The system comprises a condenser, a water storage tank and a circulating water pump connected in sequence through a pipeline, wherein: the condenser water side variable flow automatic circulation loop system has a flow automatic regulating valve or automatic flow regulation on the condenser inlet pipe of the condenser The bypass pump or the circulating water pump on the condenser inlet pipe adopts a variable flow pump, and the flow automatic regulating valve or the flow automatic adjusting bypass valve or the variable flow pump passes through the circuit connecting circuit control system.  2. The variable flow circulating heat pump water heater according to claim 1, wherein: said circuit control system comprises a main controller, a human machine interface, a signal sensor and a combined component.  The variable-flow circulating heat pump water heater according to claim 2, wherein: the signal sensor comprises a temperature sensor and a pressure sensor, wherein the temperature and pressure sensors are respectively installed in an air inlet of the evaporator and in the water storage tank. , on the refrigerant circuit system pipeline and on the pipeline of the condenser water side variable flow automatic circulation loop system.