CN201037719Y - Hot-water heat pump set for gradual increasing water temperature - Google Patents

Abstract

The utility model relates to a cascade water temperature lifting hot-water heat pump unit which belongs to hot water producing equipment which is used for cascade lifting backwater temperature of hot water. The hot-water heat pump unit adopts a combination mode of a plurality of heat pump units, and each heat pump unit has a compressor, a condenser, an expansion valve and an evaporator respectively, and the refrigerant of each heat pump device forms a singular circulation loop respectively; the condensers of each heat pump unit are in series connection one another to form a multi-section serially connected shell-tube type heat exchanger, and the backwater of hot water flows through each condenser in turn and flows from the condenser after cascade temperature lifting; the evaporators are in series connection one another to form a multi-section serially connected shell-tube type heat exchanger, and the backwater of refrigeration water flows through each condenser unit in the opposite direction of the backwater of the hot water and flows from each condenser unit after cascade temperature falling. The utility model can lift the temperature of the backwater of the hot water to a required water supply temperature gradually and can satisfy the demand of domestic hot water and heating demand, and also improves the comprehensive utility efficiency of energy.

Description

A hot water heat pump unit for stepwise raising water temperature

technical field

The utility model belongs to a medium-high temperature heat pump device for providing domestic hot water or heating hot water, especially for occasions where a large inlet and outlet temperature difference needs to be realized on the sides of frozen water and cooling water.

Background technique

At present, large-scale heat pump units have been widely used in central air-conditioning systems of public buildings. This type of heat pump generally uses water-water heat pumps, and its technology is relatively mature. For a heat pump heating system that uses groundwater or surface water as a low-temperature heat source, the water supply temperature generally needs to be higher than 55°C, but for a generally used heat pump, the difference between the condensation pressure and the evaporation pressure will be too large, and the irreversibility of the system will be greatly increased. increase, leading to low energy utilization efficiency of the system; at the same time, the temperature difference between the chilled water and cooling water inlet and outlet of the general heat pump unit is small, only about 5°C, which will increase the energy consumption of the waterway system for transmission and distribution, and the pipeline investment is too large question.

Utility model content

The purpose of this utility model is to propose a hot water heat pump unit with cascaded water temperature increase, that is, to propose a heat pump system capable of heating the lower hot water backwater cascade to a higher temperature, so as to improve the comprehensive utilization efficiency of energy, and at the same time The operation mode of large temperature difference and small flow can be realized on the side of the cold and heat source.

The technical scheme of the utility model is as follows:

A hot water heat pump unit for stepwise raising the water temperature, characterized in that the unit is composed of at least two heat pump units, each heat pump device includes a compressor, an evaporator, an expansion valve and a condenser, and each heat pump refrigerant They all form independent circulation loops according to the circulation process of compressor, condenser, expansion valve, evaporator and compressor; the condenser water system of each heat pump equipment is connected in series to form a multi-stage series shell-and-tube heat exchanger, that is, the first The inlet of the water circuit of a heat pump condenser is used as the inlet of the whole unit, and the outlet of the water circuit of the last heat pump condenser is used as the outlet of the whole unit; the evaporator water system of each heat pump equipment is connected in series to form a multi-stage series shell-and-tube heat exchange In other words, the inlet of the waterway of the last heat pump evaporator is used as the inlet of the whole unit, and the outlet of the waterway of the first heat pump evaporator is used as the outlet of the whole unit.

The biggest advantage of the utility model is that it can heat the lower hot water return water cascade to a higher temperature, and the chilled water will cool down in steps in the direction opposite to the cooling water temperature rise. Both the cooling water and the chilled water circuit of the heat pump unit can realize With the operation mode of large temperature difference and small flow, the comprehensive energy utilization efficiency of the system is greatly improved, which is mainly reflected in: first, the direction of cooling water temperature rise is opposite to that of chilled water, which reduces the temperature difference between the evaporator and condenser and reduces the irreversible Heat transfer loss, the overall performance coefficient of the unit is improved; secondly, the heat pump equipment is connected in series, and different heat pump units can be selected according to the working conditions of different temperature gradient sections to ensure that each heat pump can operate in its high-efficiency working condition; Third, adopting the method of temperature cascade rise and fall, hot water with a higher temperature (>55°C) can be produced, and at the same time, the hot water outlet temperature can be adjusted by controlling the number of heat pumps running according to the user's heat consumption requirements; fourth, The temperature difference between the supply and return water of chilled water and cooling water is increased, which reduces the energy consumption of transmission and distribution of the system and the investment of the pipeline network system.

Description of drawings

Fig. 1 is a flow diagram of an embodiment of a two-stage cascaded cascade raising water temperature and hot water heat pump unit.

Fig. 2 is a schematic flowchart of an embodiment of a three-stage cascaded cascade raising water temperature and hot water heat pump unit.

In the figure: 1a—the first stage condenser; 1b—the second stage condenser; 1c—the third stage condenser; 2a—the first stage evaporator; 2b—the second stage evaporator; 2c—the third stage evaporator ; 3a—first-stage compressor; 3b—second-stage compressor; 3c—third-stage compressor; 4a—first-stage expansion valve; 4b—second-stage expansion valve; 4c—third-stage expansion valve.

Detailed ways

Below in conjunction with accompanying drawing, concrete structure and work process of the present utility model are further described

As shown in Figure 1, the heat pump unit is composed of two heat pump units. Each heat pump unit is composed of a compressor, a condenser, an expansion valve and an evaporator, which are connected by pipelines to form two mutually independent refrigeration units. quality cycle. The condensers of the two heat pumps are connected in series to form a shell-and-tube heat exchanger, that is, the water inlet of the second-stage condenser 1b is used as the cooling water inlet of the whole unit, and the water outlet of the second-stage condenser 1b is connected with the first-stage condenser. The water inlet of the first-stage condenser 1a is connected, and the water outlet of the first-stage condenser 1a is used as the water outlet of the whole unit. The hot water return flows through the second-stage condenser 1b and the first-stage condenser 1a in turn, and is sent out after being heated by two stages; The evaporators of the two heat pumps are connected in series to form a shell-and-tube heat exchanger, that is, the water inlet of the first-stage evaporator 2a is used as the chilled water inlet of the whole unit, and the water outlet of the first-stage evaporator 2a is connected with the second-stage evaporator. The water inlet of the second-stage evaporator 2b is connected, and the water outlet of the second-stage evaporator 2b is used as the water outlet of the whole unit. The cold water return flows through the first-stage evaporator 2a and the second-stage evaporator 2b in turn, and then is sent out after being cooled step by step.

As shown in Figure 2, the heat pump unit is composed of three heat pump units. Each heat pump unit is composed of a compressor, a condenser, an expansion valve and an evaporator, which are connected by pipelines to form three mutually independent refrigeration units. quality cycle. The condensers of the three heat pumps are connected in series to form a shell-and-tube heat exchanger, that is, the water inlet of the third-stage condenser 1c is used as the cooling water inlet of the whole unit, and the water outlet of the third-stage condenser 1c is connected with the second-stage condenser The water inlet of the second-stage condenser 1b is connected, the water outlet of the second-stage condenser 1b is connected with the water inlet of the first-stage condenser 1a, and the water outlet of the first-stage condenser 1a is used as the water outlet of the whole unit, and the hot water return water flows sequentially Through the third-stage condenser 1c, the second-stage condenser 1b and the first-stage condenser 1c are heated step by step and sent out; the evaporators of the three heat pumps are connected in series to form a shell-and-tube heat exchanger, that is, the first-stage evaporator The water inlet of the evaporator 2a is used as the chilled water inlet of the whole unit, the water outlet of the first-stage evaporator 2a is connected with the water inlet of the second-stage evaporator 2b, and the water outlet of the second-stage evaporator 2b is connected with the third-stage evaporator The water inlets of 2c are connected, and the water outlet of the third-stage evaporator 2c is used as the water outlet of the whole unit. The cold water return flows through the first-stage evaporator 2a in sequence, the second-stage evaporator 2b and the third-stage evaporator 2c step by step Send out after cooling down.

Claims (1)

1. a step promotes the hot water heat pump unit of water temperature, it is characterized in that: this unit is combined by two heat pump units at least, every heat pump unit comprises compressor, evaporimeter, expansion valve and condenser, and every heat pump refrigerating working medium all forms independently closed circuit respectively by the circulation process of compressor, condenser, expansion valve, evaporimeter and compressor; The condenser water route system of each heat-pump apparatus series connection mutually becomes a shell-and-tube heat exchanger, and promptly the inlet in first heat pump condenser water route is as the inlet of whole unit, and the outlet in last heat pump condenser water route is as the outlet of whole unit; The evaporimeter water route system of each heat-pump apparatus connects mutually, and constituting connects becomes a shell-and-tube heat exchanger, be the inlet of the inlet in last evaporator with heat pump water route as whole unit, the outlet in first evaporator with heat pump water route is as the outlet of whole unit.

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