CN102865671A - Variable-flow sewage-source heat pump water heating system utilizing solar energy - Google Patents

Abstract

A variable flow solar sewage source heat pump hot water system comprises a variable flow solar heat collector system and a variable flow sewage source heat pump system. The present invention is composed of two main circulation systems, one is a circulation system composed of a solar heat collector and a hot water storage tank, a variable frequency pump is installed on the circuit from the hot water storage tank to the solar heat collector, and the water is mainly changed through the frequency conversion pump. flow, reducing the amount of heat loss in the return line and the loss of the heat pump. The other is a sewage source heat pump circulation system that uses bathing sewage as the heat source. A variable frequency pump is installed on the condenser side. The variable frequency pump adjusts the flow of cooling water to change the condensation temperature to prevent the condensation temperature from being too low and causing unstable operation of the system. Through the optimal control of the composite system, the effect of energy saving is achieved.

Description

A variable flow solar water source heat pump hot water system

technical field

The invention relates to a solar sewage source heat pump hot water system, in particular to a variable flow solar sewage source heat pump hot water system.

Background technique

With the development of the economy and the continuous improvement of people's living standards, the proportion of domestic hot water in the rapidly growing energy consumption of buildings is increasing. The combination of solar energy and water source heat pump not only meets the user's demand for hot water, but also saves energy. Since the temperature of bathing sewage is generally around 20°C, using bathing sewage as a heat source for water source heat pumps and recycling waste heat is of great significance to building energy conservation and environmental protection. In the solar water source heat pump hot water system, on the one hand, although insulation measures have been taken for the pipelines on the solar hot water circulation circuit, due to the relatively long pipeline, the heat loss on the pipe network is still relatively large; on the other hand, in the sewage source heat pump When the system is running, when the water temperature of the hot water storage tank is relatively low (especially in winter), it is easy to cause the condensation temperature to be too low, so that the oil return of the compressor cannot be normal, and the system cannot run stably.

Contents of the invention

The purpose of the present invention is to provide a system that can reduce the heat loss on the pipe network of the solar heat pump system, reduce the power loss of the heat pump, and at the same time enable the water source heat pump system to run stably, and finally improve the heating efficiency of the entire system to ensure that it can meet the needs of users in any weather Variable flow solar water source heat pump hot water system.

In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is to include a hot water storage tank with a user water supply outlet and a solar collector connected to the hot water storage tank through pipelines to form a solar collector circulation loop, and the hot water storage The first temperature sensor is installed on the tank, and the inlet solenoid valve of the solar collector and the variable frequency pump of the solar collector are installed on the outlet of the hot water storage tank and the inlet pipeline of the solar collector. A second temperature sensor is installed on the inlet pipeline;

It also includes a sewage solenoid valve connected to the sewage source. The sewage solenoid valve is connected to the evaporator through the pipeline and then discharged to the sewage treatment plant. The evaporator, expansion valve, condenser and compressor form a heating cycle loop. The condenser and hot water storage The tank constitutes a heat exchange loop; the condenser inlet and the hot water storage tank outlet are sequentially installed with a condenser frequency conversion pump and a third temperature sensor, and the condenser outlet and the hot water storage tank inlet are installed with a fourth temperature sensor.

A water pump is installed between the sewage solenoid valve and the evaporator.

来调节水流量，使冷凝温度不能过低，处在一个相对稳定的温度范围内，保证水源热泵系统能够稳定运行，达到节能的效果。In the present invention, frequency conversion pumps are respectively installed on the solar heat collector system and the sewage source heat pump system. T ₁ -T ₂ ) to adjust the flow to reduce the heat loss on the circulation pipeline; while the frequency conversion pump on the circulation circuit of the sewage source heat pump is based on the average temperature of the inlet and outlet water of the hot water storage tank on the condenser side

To adjust the water flow, so that the condensation temperature can not be too low, in a relatively stable temperature range, to ensure the stable operation of the water source heat pump system, to achieve the effect of energy saving.

Description of drawings

Fig. 1 is a schematic diagram of the overall system structure of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, the present invention includes a solar collector heating system and a sewage source heat pump heating system, the solar collector heating system includes a hot water storage tank 9 with a user water supply outlet and a water storage tank 9 through pipelines and a hot water storage tank. 9 are connected to form the solar heat collector 13 of the solar heat collector circulation loop, the first temperature sensor 10 is installed on the hot water storage tank 9, and the solar collector is installed on the outlet of the hot water storage tank 9 and the inlet pipeline of the solar heat collector 13. Heater inlet solenoid valve 11, solar heat collector variable frequency pump 12, a second temperature sensor 14 is installed on the solar heat collector 13 and the inlet pipeline of the hot water storage tank 9;

The sewage source heat pump heating system includes a sewage solenoid valve 1 connected to the sewage source. The sewage solenoid valve 1 is connected to the evaporator 3 through the water pump and then discharged to the sewage treatment plant. The evaporator 3 and the expansion valve 4, the condenser 5, and the compressor 6 A heating cycle is formed, and the condenser 5 and the hot water storage tank 9 form a heat exchange cycle; the pipeline between the inlet of the condenser 5 and the outlet of the hot water storage tank 9 is sequentially installed with a condenser frequency conversion pump 7 and a third temperature sensor 8, A fourth temperature sensor 15 is installed on the pipeline between the outlet of the condenser 5 and the inlet of the hot water storage tank 9 .

Control strategy of the present invention:

When the solar water heating system is running:

（K＞0），第一、二温度传感器10、14将温差ΔT反馈到太阳能集热器变频泵12，当K≥1时，太阳能集热器变频泵12将流量设定为满流量G_max不变；当0＜K＜1时，太阳能集热器变频泵12减小流量G为K·G_max。The heat collection cycle of the solar system is controlled by a constant temperature difference. The system sets a certain value ΔT′=10°C for the temperature difference, and the proportional relationship between ΔT and ΔT′ is

(K>0), the first and second temperature sensors 10 and 14 feed back the temperature difference ΔT to the variable frequency pump 12 of the solar collector, and when K≥1, the variable frequency pump 12 of the solar collector sets the flow rate to full flow G _max No change; when 0<K<1, the frequency conversion pump 12 of the solar heat collector reduces the flow rate G to K·G _max .

When the sewage source heat pump system is running:

The sewage source heat pump system adopts temperature average control. The system sets the average temperature of the inlet and outlet water of the hot water storage tank on the condenser side to 45°C, and the water source heat pump system can operate safely and stably. The third and fourth temperature sensors record the average temperature of the inlet and outlet water of the hot water storage tank on the condenser side Feedback to the condenser variable frequency pump 7, when the average value is ≥ 45°C, the condenser variable frequency pump 7 will set the flow rate to run at full flow G _max ; when the average value is < 45°C, the condenser variable frequency pump 7 will reduce the flow rate to In this way, the condensation temperature can be increased to ensure the stable operation of the system.

Claims (2)

1. A variable flow solar sewage source heat pump hot water system, characterized in that it includes a hot water storage tank (9) with a user water supply outlet and a solar collector connected to the hot water storage tank (9) through pipelines The solar heat collector (13) of the circulation loop, the first temperature sensor (10) is installed on the hot water storage tank (9), and the outlet of the hot water storage tank (9) is installed on the inlet pipeline of the solar heat collector (13) There are solar heat collector inlet solenoid valve (11), solar heat collector variable frequency pump (12), and a second temperature sensor (14) is installed on the solar heat collector (13) and the inlet pipeline of the hot water storage tank (9) ; It also includes the sewage solenoid valve (1) connected to the sewage source, the sewage solenoid valve (1) is connected to the evaporator (3) through the pipeline and then discharged to the sewage treatment plant, the evaporator (3) and the expansion valve (4), the condenser (5), the compressor (6) constitutes a heating circulation circuit, the condenser (5) and the hot water storage tank (9) constitute a heat exchange circulation circuit; A condenser frequency conversion pump (7) and a third temperature sensor (8) are installed in sequence on the road, and a fourth temperature sensor (15) is installed on the pipeline between the outlet of the condenser (5) and the inlet of the hot water storage tank (9). 2. The variable flow solar sewage source heat pump hot water system according to claim 1, characterized in that: a water pump (2) is installed between the sewage solenoid valve (1) and the evaporator (3).

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